3D Bioprinting of Melanoma Cells with commercially available Bio Inks - Schmidt, Sarah; Schmid, Rafael; Arkudas, Andreas; Kengelbach-Weigand, Annika; Boßerhoff, Anja Katrin (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2020)
CRIS-Team WoS Importer:2020-09-11

3D hydrogel-based microcapsules as an in vitro model to study tumorigenicity, cell migration and drug resistance. - Ertekin, Özlem; Monavari, Mahshid; Krüger, René; Fuentes Chandia, Miguel Angel; Parma, Beatrice; Letort, Gaelle; Tripal, Philipp; Boccaccini, Aldo R.; Boßerhoff, Anja Katrin; Ceppi, Paolo; Kappelmann-Fenzl, Melanie; Leal-Egaña, Aldo (Acta Biomaterialia, 2022)
In this work, we analyzed the reliability of alginate-gelatin microcapsules as artificial tumor model. These tumor-like scaffolds are characterized by their composition and stiffness (∼25 kPa), and their capability to restrict -but not hinder- cell migration, proliferation and release from confinement. Hydrogel-based microcapsules were initially utilized to detect differences in mechano-sensitivity between MCF7 and MDA-MB-231 breast cancer cells, and the endothelial cell line EA.hy926. Additionally, we used RNA-seq and transcriptomic methods to determine how the culture strategy (i.e. 2D v/s 3D) may pre-set the expression of genes involved in multidrug resistance, being then validated by performing cytotoxicological tests and assays of cell morphology. Our results show that both breast cancer cells can generate elongated multicellular spheroids inside the microcapsules, prior being released (mimicking intravasation stages), a behavior which was not observed in endothelial cells. Further, we demonstrate that cells isolated from 3D scaffolds show resistance to cisplatin, a process which seems to be strongly influenced by mechanical stress, instead of hypoxia. We finally discuss the role played by aneuploidy in malignancy and resistance to anticancer drugs, based on the increased number of polynucleated cells found within these microcapsules. Overall, our outcomes demonstrate that alginate-gelatin microcapsules represent a simple, yet very accurate tumor-like model, enabling us to mimic the most relevant malignant hints described in vivo, suggesting that confinement and mechanical stress need to be considered when studying pathogenicity and drug resistance of cancer cells in vitro. STATEMENT OF SIGNIFICANCE: In this work, we analyzed the reliability of alginate-gelatin microcapsules as an artificial tumor model. These scaffolds are characterized by their composition, elastic properties, and their ability to restrict cell migration, proliferation, and release from confinement. Our results demonstrate four novel outcomes: (i) studying cell migration and proliferation in 3D enabled discrimination between malignant and non-pathogenic cells, (ii) studying the cell morphology of cancer aggregates entrapped in alginate-gelatin microcapsules enabled determination of malignancy degree in vitro, (iii) determination that confinement and mechanical stress, instead of hypoxia, are required to generate clones resistant to anticancer drugs (i.e. cisplatin), and (iv) evidence that resistance to anticancer drugs could be due to the presence of polynucleated cells localized inside polymer-based artificial tumors.

3D information-rich databases derived from quantum mechanical calculations - Beck, Bernd; Clark, Timothy; Horn, Anselm; et al. (ACS National Meeting Book of Abstracts, 1999)

3D Spheroids Versus 3D Tumor-Like Microcapsules: Confinement and Mechanical Stress May Lead to the Expression of Malignant Responses in Cancer Cells - Fuentes-Chandía, Miguel; Vierling, Andreas; Kappelmann-Fenzl, Melanie; Monavari, Mahshid; Letort, Gaelle; Höne, Lucas; Parma, Beatrice; Antara, Sharmin Khan; Ertekin, Özlem; Palmisano, Ralf; Dong, Meng; Böpple, Kathrin; et al. (Advanced Biology, 2021)
As 2D surfaces fail to resemble the tumoral milieu, current discussions are focused on which 3D cell culture strategy may better lead the cells to express in vitro most of the malignant hints described in vivo. In this study, this question is assessed by analyzing the full genetic profile of MCF7 cells cultured either as 3D spheroids-considered as “gold standard” for in vitro cancer research- or immobilized in 3D tumor-like microcapsules, by RNA-Seq and transcriptomic methods, allowing to discriminate at big-data scale, which in vitro strategy can better resemble most of the malignant features described in neoplastic diseases. The results clearly show that mechanical stress, rather than 3D morphology only, stimulates most of the biological processes involved in cancer pathogenicity, such as cytoskeletal organization, migration, and stemness. Furthermore, cells entrapped in hydrogel-based scaffolds are likely expressing other physiological hints described in malignancy, such as the upregulated expression of metalloproteinases or the resistance to anticancer drugs, among others. According to the knowledge, this study represents the first attempt to answer which 3D experimental system can better mimic the neoplastic architecture in vitro, emphasizing the relevance of confinement in cancer pathogenicity, which can be easily achieved by using hydrogel-based matrices.
CRIS-Team Scopus Importer:2021-05-28
Keywords: 3D cancer models; 3D cell culture; biomaterials for cancer research; solid stress; tumor-like microcapsules

Ablation of Protein Kinase CK2β in Skeletal Muscle Fibers Interferes with Their Oxidative Capacity - Eiber, Nane; Simeone, Luca; Hashemolhosseini, Said (Pharmaceuticals, 2017)
The tetrameric protein kinase CK2 was identified playing a role at neuromuscular junctions by studying CK2β-deficient muscle fibers in mice, and in cultured immortalized C2C12 muscle cells after individual knockdown of CK2α and CK2β subunits. In muscle cells, CK2 activity appeared to be at least required for regular aggregation of nicotinic acetylcholine receptors, which serves as a hallmark for the presence of a postsynaptic apparatus. Here, we set out to determine whether any other feature accompanies CK2β-deficient muscle fibers. Hind limb muscles gastrocnemius, plantaris, and soleus of adult wildtype and CK2β-deficient mice were dissected, cross-sectioned, and stained histochemically by Gomori trichrome and for nicotinamide adenine dinucleotide (NADH) dehydrogenase and succinate dehydrogenase (SDH) enzymatic activities. A reduction of oxidative enzymatic activity was determined for CK2β-deficient muscle fibers in comparison with wildtype controls. Importantly, the CK2β-deficient fibers, muscle fibers that typically exhibit high NADH dehydrogenase and SDH activities, like slow-type fibers, showed a marked reduction in these activities. Altogether, our data indicate additional impairments in the absence of CK2β in skeletal muscle fibers, pointing to an eventual mitochondrial myopathy.
EVALuna2:33489

Absence of polyomavirus JC in glial brain tumors and glioma-derived cell lines - Wegner, Michael; et al. (Glia, 1998)
The human neurotropic papovavirus JC, a close relative of simian virus 40, has been associated with the formation of brain tumors in humans because of its ability to induce such tumors in other primates under experimental conditions. Here we have analyzed 30 brain tumors classified as either oligodendroglioma or astrocytoma and 22 cell lines derived from human gliomas for the presence of JC viral sequences using polymerase chain reaction with two different sets of primers. None of the tumors or cell lines contained JC viral sequences. Similarly, we failed to detect expression of JC T antigen in any of 26 human glioma lines analyzed in this study. We conclude that JC virus is not a major cause of human brain tumors.
UnivIS-Import:2015-03-05:Pub.1998.med.IB.LPCIPDBI.absenc
Keywords: Astrocytoma; Glioblastoma; JCV; Oligodendroglioma; PML

Absence of the RING domain in MID1 results in patterning defects in the developing human brain - Frank, Sarah; Gabassi, Elisa; Käseberg, Stephan; Bertin, Marco; Zografidou, Lea; Pfeiffer, Daniela; Brennenstuhl, Heiko; Falk, Sven; Karow, Marisa; Schweiger, Susann (Life Science Alliance, 2024)
The X-linked form of Opitz BBB/G syndrome (OS) is a monogenic disorder in which symptoms are established early during embryonic development. OS is caused by pathogenic variants in the X-linked gene MID1 Disease-associated variants are distributed across the entire gene locus, except for the N-terminal really interesting new gene (RING) domain that encompasses the E3 ubiquitin ligase activity. By using genome-edited human induced pluripotent stem cell lines, we here show that absence of isoforms containing the RING domain of MID1 causes severe patterning defects in human brain organoids. We observed a prominent neurogenic deficit with a reduction in neural tissue and a concomitant increase in choroid plexus-like structures. Transcriptome analyses revealed a deregulation of patterning pathways very early on, even preceding neural induction. Notably, the observed phenotypes starkly contrast with those observed in MID1 full-knockout organoids, indicating the presence of a distinct mechanism that underlies the patterning defects. The severity and early onset of these phenotypes could potentially account for the absence of patients carrying pathogenic variants in exon 1 of the MID1 gene coding for the N-terminal RING domain.
CRIS-Team Scopus Importer:2024-02-02

Absolute quantification of DcR3 and GDF15 from human serum by LC-ESI MS - Lancrajan, Ioana Maria; Schneider-Stock, Regine; Naschberger, Elisabeth; Schellerer, Vera; Stürzl, Michael; Enz, Ralf (Journal of Cellular and Molecular Medicine, 2015)
Biomarkers are widely used in clinical diagnosis, prognosis and therapy monitoring. Here, we developed a protocol for the efficient and selective enrichment of small and low concentrated biomarkers from human serum, involving a 95% effective depletion of high-abundant serum proteins by partial denaturation and enrichment of low-abundant biomarkers by size exclusion chromatography. The recovery of low-abundance biomarkers was above 97%. Using this protocol, we quantified the tumour markers DcR3 and growth/differentiation factor (GDF)15 from 100 ?l human serum by isotope dilution mass spectrometry, using (15) N metabolically labelled and concatamerized fingerprint peptides for the both proteins. Analysis of three different fingerprint peptides for each protein by liquid chromatography electrospray ionization mass spectrometry resulted in comparable concentrations in three healthy human serum samples (DcR3: 27.23 ± 2.49 fmol/ml; GDF15: 98.11 ± 0.49 fmol/ml). In contrast, serum levels were significantly elevated in tumour patients for DcR3 (116.94 ± 57.37 fmol/ml) and GDF15 (164.44 ± 79.31 fmol/ml). Obtained data were in good agreement with ELISA and qPCR measurements, as well as with literature data. In summary, our protocol allows the reliable quantification of biomarkers, shows a higher resolution at low biomarker concentrations than antibody-based strategies, and offers the possibility of multiplexing. Our proof-of-principle studies in patient sera encourage the future analysis of the prognostic value of DcR3 and GDF15 for colon cancer patients in larger patient cohorts.
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Acidic tumor microenvironment in human melanoma - Böhme, Ines; Boßerhoff, Anja Katrin (Pigment Cell & Melanoma Research, 2016)
One characteristic of solid tumors such as malignant melanoma is the acidification of the tumor microenvironment. The deregulation of cancer cell metabolism is considered a main cause of extracellular acidosis. Here, cancer cells utilize aerobic glycolysis instead of oxidative phosphorylation even under normoxic conditions, as originally described by Otto Warburg. These metabolic alterations cause enhanced acid production, especially of lactate and carbon dioxide (CO2 ). The extensive production of acidic metabolites and the enhanced acid export to the extracellular space cause a consistent acidification of the tumor microenvironment, thus promoting the formation of an acid-resistant tumor cell population with increased invasive and metastatic potential. As melanoma is one of the deadliest and most metastatic forms of cancer, understanding the effects of this extracellular acidosis on human melanoma cells with distinct metastatic properties is important. The aim of this review was to summarize recent studies of the acidification of the tumor microenvironment, focusing on the specific effects of the acidic milieu on melanoma cells and to give a short overview of therapeutic approaches.
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Acidification is an essential process of cold atmospheric plasma and promotes the anti-cancer effect on malignant melanoma cells - Schneider, Christin; Gebhardt, Lisa; Arndt, Stephanie; Karrer, Sigrid; Zimmermann, Julia L.; Fischer, Michael; Boßerhoff, Anja Katrin (Cancers, 2019)
(1) Background: Cold atmospheric plasma (CAP) is ionized gas near room temperature. The anti-cancer effects of CAP were confirmed for several cancer types and were attributed to CAP-induced reactive species. However, the mode of action of CAP is still not well understood. (2) Methods: Changes in cytoplasmic Ca2+ level after CAP treatment of malignant melanoma cells were analyzed via the intracellular Ca2+ indicator fura-2 AM. CAP-produced reactive species were determined by fluorescence spectroscopic and protein nitration by Western Blot analysis. (3) Results: CAP caused a strong acidification of water and solutions that were buffered with the so-called Good buffers, while phosphate-buffered solutions with higher buffer capacity showed minor pH reductions. The CAP-induced Ca2+ influx in melanoma cells was stronger in acidic pH than in physiological conditions. NO formation that is induced by CAP was dose-and pH-dependent and CAP-treated solutions only caused protein nitration in cells under acidic conditions. (4) Conclusions: We describe the impact of CAP-induced acidification on the anti-cancer effects of CAP. A synergistic effect of CAP-induced ROS, RNS, and acidic conditions affected the intracellular Ca2+ level of melanoma cells. As the microenvironment of tumors is often acidic, further acidification might be one reason for the specific anti-cancer effects of CAP.
CRIS-Team Scopus Importer:2019-06-21
Keywords: Acidification; Calcium signaling; Cold atmospheric plasma; Malignant melanoma; Nitration

Acidified nitrite contributes to the antitumor effect of cold atmospheric plasma on melanoma cells - Zimmermann, Tom; Gebhardt, Lisa; Kreiß, Lucas; Schneider, Christin; Arndt, Stephanie; Karrer, Sigrid; Friedrich, Oliver; Fischer, Michael Jochen Marco; Boßerhoff, Anja Katrin (International Journal of Molecular Sciences, 2021)
Cold atmospheric plasma (CAP) is partially ionized gas near room temperature with previously reported antitumor effects. Despite extensive research and growing interest in this technol-ogy, active components and molecular mechanisms of CAP are not fully understood to date. We used Raman spectroscopy and colorimetric assays to determine elevated nitrite and nitrate levels after treatment with a MiniFlatPlaster CAP device. Previously, we demonstrated CAP-induced acidification. Cellular effects of nitrite and strong extracellular acidification were assessed using live-cell imaging of intracellular Ca2+ levels, cell viability analysis as well as quantification of p21 and DNA damage. We further characterized these observations by analyzing established molecular effects of CAP treatment. A synergistic effect of nitrite and acidification was found, leading to strong cytotoxicity in melanoma cells. Interestingly, protein nitration and membrane damage were absent after treatment with acidified nitrite, thereby challenging their contribution to CAP-induced cyto-toxicity. Further, phosphorylation of ERK1/2 was increased after treatment with both acidified ni-trite and indirect CAP. This study characterizes the impact of acidified nitrite on melanoma cells and supports the importance of RNS during CAP treatment. Further, it defines and evaluates im-portant molecular mechanisms that are involved in the cancer cell response to CAP.
CRIS-Team Scopus Importer:2021-04-16
Keywords: Acidification; Acidified nitrite; Cold atmospheric plasma; Malignant melanoma; Membrane damage; Nitration; Nitrite

A comparative study of HIV-1 and HTLV-I protease structure and dynamics reveals a conserved residue interaction network - Ruecker, Pia; Horn, Anselm; Meiselbach, Heike; Sticht, Heinrich (Journal of Molecular Modeling, 2011)
The two retroviruses human T-lymphotropic virus type I (HTLV-I) and human immunodeficiency virus type 1 (HIV-1) are the causative agents of severe and fatal diseases including adult T-cell leukemia and the acquired immune deficiency syndrome (AIDS). Both viruses code for a protease that is essential for replication and therefore represents a key target for drugs interfering with viral infection. The retroviral proteases from HIV-1 and HTLV-I share 31% sequence identity and high structural similarities. Yet, their substrate specificities and inhibition profiles differ substantially. In this study, we performed all-atom molecular dynamics (MD) simulations for both enzymes in their ligand-free states and in complex with model substrates in order to compare their dynamic behaviors and enhance our understanding of the correlation between sequence, structure, and dynamics in this protein family. We found extensive similarities in both local and overall protein dynamics, as well as in the energetics of their interactions with model substrates. Interestingly, those residues that are important for strong ligand binding are frequently not conserved in sequence, thereby offering an explanation for the differences in binding specificity. Moreover, we identified an interaction network of contacts between conserved residues that interconnects secondary structure elements and serves as a scaffold for the protein fold. This interaction network is conformationally stable over time and may provide an explanation for the highly similar dynamic behavior of the two retroviral proteases, even in the light of their rather low overall sequence identity.
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A comprehensive expression analysis of the MIA gene family in malignancies: MIA gene family members are novel, useful markers of esophageal, lung, and cervical squamous cell carcinoma - Sasahira, Tomonori; Kirita, Tadaaki; Nishiguchi, Yukiko; Kurihara, Miyako; Nakashima, Chie; Boßerhoff, Anja Katrin; Kuniyasu, Hiroki (Oncotarget, 2016)
Melanoma inhibitory activity (MIA) gene family members include MIA, MIA2, and Transport and Golgi organization protein 1 (TANGO). Although MIA gene family members have several tumor-related functions, their detailed roles in malignancies remain poorly elucidated. In this study, 477 tumor specimens were subjected to immunohistochemical screening to evaluate MIA gene family expression. For a validation analysis, we also examined the association between MIA gene family expression and clinicopathological factors in 66 cases of esophageal cancer, 145 cases of lung cancer, and 126 cases of cervical cancer. The frequency of MIA gene family expression was higher among squamous cell carcinomas than among other tumor types subjected to screening. In the validation analysis, MIA gene family staining was observed frequently in esophageal and lung cancers associated with nodal and/or distant metastasis. In cervical cancers, MIA and TANGO immunostaining also correlated with tumor progression and metastasis. Furthermore, MIA2 expression levels in invasive cervical cancer were upregulated relative to those in cervical intraepithelial neoplasia 3. A disease-free survival analysis revealed that MIA-, MIA2, or TANGO-positive patients had a significantly shorter disease-free survival than did those patients who were negative. Our results suggest that MIA, MIA2, and TANGO may be useful diagnostic and therapeutic molecular targets in human malignancies.
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Activating enhancer binding protein 2 epsilon (AP-2?)-deficient mice exhibit increased matrix metalloproteinase 13 expression and progressive osteoarthritis development - Niebler, Stephan; Schubert, Thomas; Hunziker, Ernst B.; Boßerhoff, Anja Katrin (Arthritis Research & Therapy, 2015)
The transcription factor activating enhancer binding protein 2 epsilon (AP-2?) was recently shown to be expressed during chondrogenesis as well as in articular chondrocytes of humans and mice. Furthermore, expression of AP-2? was found to be upregulated in affected cartilage of patients with osteoarthritis (OA). Despite these findings, adult mice deficient for AP-2? (Tfap2e(-/-)) do not exhibit an obviously abnormal cartilaginous phenotype. We therefore analyzed embryogenesis of Tfap2e(-/-) mice to elucidate potential transient abnormalities that provide information on the influence of AP-2? on skeletal development. In a second part, we aimed to define potential influences of AP-2? on articular cartilage function and gene expression, as well as on OA progression, in adult mice.Murine embryonic development was accessed via in situ hybridization, measurement of skeletal parameters and micromass differentiation of mesenchymal cells. To reveal discrepancies in articular cartilage of adult wild-type (WT) and Tfap2e(-/-) mice, light and electron microscopy, in vitro culture of cartilage explants, and quantification of gene expression via real-time PCR were performed. OA was induced via surgical destabilization of the medial meniscus in both genotypes, and disease progression was monitored on histological and molecular levels.Only minor differences between WT and embryos deficient for AP-2? were observed, suggesting that redundancy mechanisms effectively compensate for the loss of AP-2? during skeletal development. Surprisingly, though, we found matrix metalloproteinase 13 (Mmp13), a major mediator of cartilage destruction, to be significantly upregulated in articular cartilage of adult Tfap2e(-/-) mice. This finding was further confirmed by increased Mmp13 activity and extracellular matrix degradation in Tfap2e(-/-) cartilage explants. OA progression was significantly enhanced in the Tfap2e(-/-) mice, which provided evidence for in vivo relevance. This finding is most likely attributable to the increased basal Mmp13 expression level in Tfap2e(-/-) articular chondrocytes that results in a significantly higher total Mmp13 expression rate during OA as compared with the WT.We reveal a novel role of AP-2? in the regulation of gene expression in articular chondrocytes, as well as in OA development, through modulation of Mmp13 expression and activity.
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Activation and regulation of endogenous retroviral genes in the human pituitary gland and related endocrine tumours - Buslei, R.; Strissel, Pamela; Henke, Christine; Schey, Regina; Lang, Nadine; Ruebner, M.; Stolt, Claus; Fabry, Ben; Buchfelder, Michael; Strick, Reiner (Neuropathology and Applied Neurobiology, 2015)
Adenohypophysis (AH) hormone-producing cells represent the origin of diverse groups of pituitary adenomas (PA). Deregulation of hypothalamic hormone receptors, growth factors and cAMP signalling have been implicated in the aetiology of PA. Endogenous retroviruses (ERVs) are derived from past exogenous retroviral infections and represent more than 8% of the human genome. Some ERV genes encode open reading frames and produce functional proteins, for example, the ERVW-1 envelope gene Syncytin-1, essential for placentogenesis, but also deregulated in human tumours. Data concerning ERV expression in the AH and related endocrine tumours are missing.Syncytin-1 protein was analysed in normal AH (n = 15) and compared with five PA subtypes (n = 117) by immunohistochemistry. Absolute gene expression of 20 ERV functional envelope genes and ERVW-5 gag was measured. PA tissues were examined for Syncytin-1 and the cAMP signalling marker phospho-CREB-Ser133 using immunohistochemistry. Isolated primary human PA cells were treated with different hormones. Murine embryonic and adult pituitary gland ERV expressions were compared with human AH.Syncytin-1 protein colocalized with corticotropic cells of AH. In contrast, all PA demonstrated significant Syncytin-1 protein overexpression, supporting deregulation. All other ERV genes showed significant up-regulations in different PA subtypes. Phospho-CREB-Ser133 and Syncytin-1 colocalized in PA cells. Cultivated primary PA cells with ACTH or CRH induced their respective receptors and ERV genes. Syncytin-A/-B, murine orthologues to human Syncytin-1/-2, localized to embryonic and adult pituitary glands demonstrating functional mammalian conservation.Deregulated ERV genes may contribute to PA development via cAMP signalling.
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Activation of AP-1 and NF-kappa B transcription factors is involved in hydrogen peroxide-induced apoptopic cell death of oligodendrocytes - Wegner, Michael; et al. (Journal of Neurochemistry, 1999)
UnivIS-Import:2015-03-05:Pub.1999.med.IB.LPCIPDBI.activa

Activation of Krox20 gene expression by Sox10 in myelinating Schwann cells. - Reiprich, Simone; Müller, Jana; Wegner, Michael; et al. (Journal of Neurochemistry, 2010)
The high-mobility group domain transcription factor Sox10 is believed to influence myelination in Schwann cells by directly activating myelin genes and by inducing Krox20 as a pivotal regulator of peripheral myelination. Krox20 induction at this stage is thought to be mediated by the myelinating Schwann cell element 35 kb downstream of the Krox20 transcriptional start site and requires cooperation with Oct6. Here, we prove for the first time in vivo that Schwann cell-specific Krox20 expression indeed depends on Sox10. We also provide evidence that Sox10 functions through multiple, mostly monomeric binding sites in the myelinating Schwann cell element in a manner that should render the enhancer exquisitely sensitive to Sox10 levels. Synergistic activation of the enhancer by Sox10 and Oct6 furthermore does not involve cooperative binding to closely spaced binding sites in defined composite elements. Nevertheless, the POU domain of Oct6 and the high-mobility group domain of Sox10 as the two DNA-binding domains were both essential indicating that each transcription factor has to bind independently to DNA. Whereas the POU domain was the only important region of Oct6, two further Sox10 domains were required for synergistic Krox20 activation. These were the carboxyterminal transactivation domain and the conserved K2 domain in the central portion of Sox10. All required regions are conserved in several closely related POU and Sox proteins thus explaining why Oct6 and Sox10 can be replaced by their relatives during Krox20 induction in myelinating Schwann cells. © 2009 International Society for Neurochemistry.
UnivIS-Import:2015-03-09:Pub.2010.med.IB.LPCIPDBI.activa
Keywords: Glia; High-mobility group; Neural crest; Peripheral nervous system; POU; Transcription factor

Activation of SV40 DNA replication in vivo by amplification-promoting sequences of the mouse ribosomal gene cluster - Wegner, Michael; et al. (Chromosoma, 1998)
UnivIS-Import:2015-03-05:Pub.1998.med.IB.LPCIPDBI.activa

Activin Controls Ethanol Potentiation of Inhibitory Synaptic Transmission Through GABAA Receptors and Concomitant Behavioral Sedation - Zheng, Fang; Puppel, Anne; Hubert, Sabine E.; Link, Andrea; Eulenburg, Volker; van Brederode, Johannes; Müller, Christiane; Alzheimer, Christian (Neuropsychopharmacology, 2016)
Activin, a member of the transforming growth factor-? family, exerts multiple functions in the nervous system. Originally identified as a neurotrophic and -protective agent, increasing evidence implicates activin also in the regulation of glutamatergic and GABAergic neurotransmission in brain regions associated with cognitive and affective functions. To explore how activin impacts on ethanol potentiation of GABA synapses and related behavioral paradigms, we used an established transgenic model of disrupted activin receptor signaling, in which mice express a dominant-negative activin receptor IB mutant (dnActRIB) under the control of the CaMKII? promoter. Comparison of GABAA receptor currents in hippocampal neurons from dnActRIB mice and wild-type mice showed that all concentrations of ethanol tested (30-150 mM) produced much stronger potentiation of phasic inhibition in the mutant preparation. In dentate granule cells of dnActRIB mice, tonic GABA inhibition was more pronounced than in wild-type neurons, but remained insensitive to low ethanol (30 mM) in both preparations. The heightened ethanol sensitivity of phasic inhibition in mutant hippocampi resulted from both pre- and postsynaptic mechanisms, the latter probably involving PKC?. At the behavioral level, ethanol produced significantly stronger sedation in dnActRIB mice than in wild-type mice, but did not affect consumption of ethanol or escalation after withdrawal. We link the abnormal narcotic response of dnActRIB mice to ethanol to the excessive potentiation of inhibitory neurotransmission. Our study suggests that activin counteracts oversedation from ethanol by curtailing its augmenting effect at GABA synapses.
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Activin Signaling in the Pathogenesis and Therapy of Neuropsychiatric Diseases - Link, Andrea; Zheng, Fang; Alzheimer, Christian (Frontiers in Molecular Neuroscience, 2016)
Activins are members of the transforming growth factor β (TGFβ) family and serve as multifunctional regulatory proteins in many tissues and organs. In the brain, activin A, which is formed by two disulfide-linked βA subunits, is recognized as the predominant player in activin signaling. Over the last years, considerable progress has been made in elucidating novel and unexpected functions of activin in the normal and diseased brain and in deciphering the underlying molecular mechanisms. Initially identified as a neurotrophic and protective factor during development and in several forms of acute injury, the scope of effects of activin A in the adult central nervous system (CNS) has been considerably broadened by now. Here, we will highlight recent findings that bear significance for a better understanding of the pathogenesis of various neuropsychiatric diseases and might hold promise for novel therapeutic strategies. While the basal level of activin A in the adult brain is low, significant short-term up-regulation occurs in response to increased neuronal activity. In fact, brief exposure to an enriched environment (EE) is already sufficient to considerably strengthen activin signaling. Enhancement of this pathway tunes the performance of glutamatergic and GABAergic synapses in a fashion that impacts on cognitive functions and affective behavior, counteracts death-inducing signals through extrasynaptic NMDA receptors (NMDARs), and stimulates adult neurogenesis in the hippocampus. We will discuss how impaired activin signaling is involved in anxiety disorders, depression, drug dependence, and neurodegenerative diseases such as Alzheimer's and Parkinson's, and how reinforcement of activin signaling might be exploited for therapeutic interventions.
EVALuna2:32811

ADSCs and adipocytes are the main producers in the autotaxin-lysophosphatidic acid axis of breast cancer and healthy mammary tissue in vitro - Schmid, Rafael; Wolf, Katharina; Robering, Jan Willem; Strauss, Selina; Strissel, Pamela; Strick, Reiner; Rübner, Matthias; Fasching, Peter; Horch, Raymund E.; Kremer, Andreas; Boos, Anja; Weigand, Annika (BMC Cancer, 2018)
BACKGROUND: Breast cancer is the most common malignancy in women affecting one out of eight females throughout their lives. Autotaxin (ATX) is upregulated in breast cancer which results in increased lysophosphatidic acid (LPA) formation within the tumor. This study's aim was to identify the role of different mammary cell populations within the ATX-LPA axis. METHODS: Epithelial-cell-adhesion-molecule-positive (EpCAM) and -negative cells from breast tumors, adipose-derived stem cells (ADSCs) of tumor-adjacent and tumor-distant mammary fat were isolated and compared to healthy ADSCs, mammary epithelial cells (HMECs), and mesenchymal cells (MES) of healthy mammary tissue (n = 4 each) and further to well-established breast (cancer) cell lines. RESULTS: mRNA expression analyses revealed that ADSCs and MES largely expressed LPA receptor 1 (LPAR1) while epithelial cells mainly expressed LPAR6. LPA 18:1 activated all the cell populations and cell lines by rise in cytosolic free calcium concentrations. MES and ADSCs expressed ATX whereas epithelial cells did not. ADSCs revealed the highest expression in ATX with a significant decline after adipogenic differentiation in healthy ADSCs, whereas ATX expression increased in ADSCs from tumor patients. Breast (cancer) cell lines did not express ATX. Transmigration of MES was stimulated by LPA whereas an inhibitory effect was observed in epithelial cells with no differences between tumors and healthy cells. Triple-negative breast cancer (TNBC) cell lines were also stimulated and the transmigration partly inhibited using the LPA receptor antagonist Ki16425. CONCLUSIONS: We here show that each mammary cell population plays a different role in the ATX-LPA axis with ADSCs and adipocytes being the main source of ATX in tumor patients in our experimental setting. Inhibitors of this axis may therefore present a valuable target for pharmacological therapies.
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A Dual-Pathogen Mitral Valve Endocarditis Caused by Coxiella burnetii and Streptococcus gordonii—Which Came First? - Kaemmerer, Ann-Sophie; Ciotola, Francesco; Geißdörfer, Walter; Harig, Frank; Mattner, Jochen; Seitz, Tatjana; Suleiman, Mathieu; Weyand, Michael; Heim, Christian (Pathogens, 2023)
Infective endocarditis (IE) is still a life-threatening disease with high morbidity and mortality. While usually caused by a single bacterium, poly-microbial infective endocarditis (IE) is rare. Here, we report a (blood-culture-negative) dual pathogen mitral valve IE caused by Coxiella burnetii and Streptococcus gordonii: A 53-year-old woman was presented to an internal medicine department with abdominal pain for further evaluation. Within the diagnostic work up, transthoracic echocardiography (TTE) revealed an irregularly shaped echogenic mass (5 × 13 mm) adherent to the edge of the posterior mitral valve leaflet and protruding into the left atrium. As infected endocarditis was suspected, blood cultures were initially obtained, but they remained negative. Chronic Q fever infection was diagnosed using serologic testing. After the occurrence of cerebral thromboembolic events, the patient was admitted for mitral valve surgery. Intraoperatively, a massively destructed mitral valve with adhering vegetations was noted. Examination of the mitral valve by broad-range bacterial polymerase chain reaction (PCR) and amplicon sequencing confirmed Coxiella burnetii infection and yielded Streptococcus gordonii as the second pathogen. Based on the detailed diagnosis, appropriate antibiotic therapy of both pathogens was initiated, and the patient could be discharged uneventfully on the 11th postoperative day after a successful minimal-invasive mitral valve replacement.
CRIS-Team Scopus Importer:2023-10-20
Keywords: blood-culture-negative endocarditis; Coxiella burnetii; dual-pathogen endocarditis; endocarditis; minimally invasive mitral valve replacement; polymicrobial infective endocarditis; Q fever; Streptococcus gordonii

A dual role for SOX10 in the maintenance of the postnatal melanocyte lineage and the differentiation of melanocyte stem cell progenitors - Harris, Melissa L.; Buac, Kristina; Shakhova, Olga; Hakami, Ramin M.; Wegner, Michael; Sommer, Lukas; Pavan, William J. (PLoS Genetics, 2013)
During embryogenesis, the transcription factor, Sox10, drives the survival and differentiation of the melanocyte lineage. However, the role that Sox10 plays in postnatal melanocytes is not established. We show in vivo that melanocyte stem cells (McSCs) and more differentiated melanocytes express SOX10 but that McSCs remain undifferentiated. Sox10 knockout (Sox10(fl); Tg(Tyr::CreER)) results in loss of both McSCs and differentiated melanocytes, while overexpression of Sox10 (Tg(DctSox10)) causes premature differentiation and loss of McSCs, leading to hair graying. This suggests that levels of SOX10 are key to normal McSC function and Sox10 must be downregulated for McSC establishment and maintenance. We examined whether the mechanism of Tg(DctSox10) hair graying is through increased expression of Mitf, a target of SOX10, by asking if haploinsufficiency for Mitf (Mitf(vga9) ) can rescue hair graying in Tg(DctSox10) animals. Surprisingly, Mitf(vga9) does not mitigate but exacerbates Tg(DctSox10) hair graying suggesting that MITF participates in the negative regulation of Sox10 in McSCs. These observations demonstrate that while SOX10 is necessary to maintain the postnatal melanocyte lineage it is simultaneously prevented from driving differentiation in the McSCs. This data illustrates how tissue-specific stem cells can arise from lineage-specified precursors through the regulation of the very transcription factors important in defining that lineage.
EVALuna2:4946

Adult astrogenesis and functional astrocyte heterogeneity in the adult mouse hippocampus - Beckervordersandforth, Ruth (GLIA, 2019)
CRIS-Team WoS Importer:2020-01-10

Adult-onset degeneration of adipose tissue in mice deficient for the Sox8 transcription factor. - Wegner, Michael; et al. (Journal of Lipid Research, 2009)
Although the transcription factor Sox8 is broadly expressed during embryogenesis in developing ectodermal and mesodermal tissues, mice develop surprisingly normally in the absence of Sox8. Phenotypes in adult Sox8-deficient mice include mild osteopenia, late-onset male infertility, and reduced weight. We show here that progressive degeneration of adipose tissue in adult Sox8-deficient mice significantly contributes to weight reduction. Although serum levels of leptin, IGF-1, and noradrenaline were altered in Sox8-deficient mice, these changes could not explain the observed phenotype. Other serum parameters, including indicators of glucose metabolism, were largely normal. However, expression of the preadipocyte marker Pref-1 was elevated in adipose tissues of Sox8-deficient mice. This increase correlated with an impaired differentiation of Sox8-deficient fibroblasts to adipocytes in culture, a defect that could be rescued by reintroducing Sox8 into the cells. Furthermore, Sox8 levels were higher in mesodermal precursors than in mature adipocytes. We postulate a precursor-intrinsic role of Sox8 during replenishment of the adipocyte pool in adult mice and assume that disturbance of this function significantly contributes to adipose tissue degeneration in Sox8-deficient mice. Copyright © 2009 by the American Society for Biochemistry and Molecular Biology, Inc.
UnivIS-Import:2015-03-09:Pub.2009.med.IB.LPCIPDBI.adulto
Keywords: High-mobility-group; Mesoderm; Sry; Transgenic mouse model

A fully human anti-BMP6 antibody reduces the need for erythropoietin in rodent models of the anemia of chronic disease - Petzer, Verena; Tymoszuk, Piotr; Asshoff, Malte; Carvalho, Joana; Papworth, Jonathan; Deantonio, Cecilia; Bayliss, Luke; Wake, Matthew Stephen; Seifert, Markus; Brigo, Natascha; Valente de Souza, Lara; Hilbe, Richard; et al. (Blood, 2020)
Recombinant erythropoietin (EPO) and iron substitution are a standard of care for treatment of anemias associated with chronic inflammation, including anemia of chronic kidney disease. A black box warning for EPO therapy and concerns about negative side effects related to high-dose iron supplementation as well as the significant proportion of patients becoming EPO resistant over time explains the medical need to define novel strategies to ameliorate anemia of chronic disease (ACD). As hepcidin is central to the iron-restrictive phenotype in ACD, therapeutic approaches targeting hepcidin were recently developed. We herein report the therapeutic effects of a fully human anti-BMP6 antibody (KY1070) either as monotherapy or in combination with Darbepoetin alfa on iron metabolism and anemia resolution in 2 different, well-established, and clinically relevant rodent models of ACD. In addition to counteracting hepcidin-driven iron limitation for erythropoiesis, we found that the combination of KY1070 and recombinant human EPO improved the erythroid response compared with either monotherapy in a qualitative and quantitative manner. Consequently, the combination of KY1070 and Darbepoetin alfa resulted in an EPO-sparing effect. Moreover, we found that suppression of hepcidin via KY1070 modulates ferroportin expression on erythroid precursor cells, thereby lowering potentially toxic-free intracellular iron levels and by accelerating erythroid output as reflected by increased maturation of erythrocyte progenitors. In summary, we conclude that treatment of ACD, as a highly complex disease, becomes more effective by a multifactorial therapeutic approach upon mobilization of endogenous iron deposits and stimulation of erythropoiesis.
CRIS-Team Scopus Importer:2020-09-11

A gene regulatory architecture that controls region-independent dynamics of oligodendrocyte differentiation - Cantone, Martina; Küspert, Melanie; Reiprich, Simone; Lai, Xin; Eberhardt, Martin; Göttle, Peter; Beyer, Felix; Azim, Kasum; Küry, Patrick; Wegner, Michael; Vera, Julio (Glia, 2019)
Oligodendrocytes (OLs) facilitate information processing in the vertebrate central nervous system via axonal ensheathment. The structure and dynamics of the regulatory network that mediates oligodendrogenesis are poorly understood. We employed bioinformatics and meta-analysis of high-throughput datasets to reconstruct a regulatory network underpinning OL differentiation. From this network, we identified families of feedforward loops comprising the transcription factors (TFs) Olig2, Sox10, and Tcf7l2 and their targets. Among the targets, we found eight other TFs related to OL differentiation, suggesting a hierarchical architecture in which some TFs (Olig2, Sox10, and Tcf7l2) regulate via feedforward loops the expression of others (Sox2, Sox6, Sox11, Nkx2-2, Nkx6-2, Hes5, Myt1, and Myrf). Model simulations with a kinetic model reproduced the mechanisms of OL differentiation only when in the model, Sox10-mediated repression of Tcf7l2 by miR-338/miR-155 was introduced, a prediction confirmed in genetic functional experiments. Additional model simulations suggested that OLs from dorsal regions emerge through BMP/Sox9 signaling.
EVALuna2:35752

A glutaminyl cyclase-catalyzed α-synuclein modification identified in human synucleinopathies - Hartlage-Rübsamen, Maike; Bluhm, Alexandra; Moceri, Sandra; Machner, Lisa; Köppen, Janett; Schenk, Mathias; Hilbrich, Isabel; Holzer, Max; Weidenfeller, Martin; Richter, Franziska; Coras, Roland; Serrano, Geidy E.; et al. (Acta Neuropathologica, 2021)
Parkinson’s disease (PD) is a progressive neurodegenerative disorder that is neuropathologically characterized by degeneration of dopaminergic neurons of the substantia nigra (SN) and formation of Lewy bodies and Lewy neurites composed of aggregated α-synuclein. Proteolysis of α-synuclein by matrix metalloproteinases was shown to facilitate its aggregation and to affect cell viability. One of the proteolysed fragments, Gln79-α-synuclein, possesses a glutamine residue at its N-terminus. We argue that glutaminyl cyclase (QC) may catalyze the pyroglutamate (pGlu)79-α-synuclein formation and, thereby, contribute to enhanced aggregation and compromised degradation of α-synuclein in human synucleinopathies. Here, the kinetic characteristics of Gln79-α-synuclein conversion into the pGlu-form by QC are shown using enzymatic assays and mass spectrometry. Thioflavin T assays and electron microscopy demonstrated a decreased potential of pGlu79-α-synuclein to form fibrils. However, size exclusion chromatography and cell viability assays revealed an increased propensity of pGlu79-α-synuclein to form oligomeric aggregates with high neurotoxicity. In brains of wild-type mice, QC and α-synuclein were co-expressed by dopaminergic SN neurons. Using a specific antibody against the pGlu-modified neo-epitope of α-synuclein, pGlu79-α-synuclein aggregates were detected in association with QC in brains of two transgenic mouse lines with human α-synuclein overexpression. In human brain samples of PD and dementia with Lewy body subjects, pGlu79-α-synuclein was shown to be present in SN neurons, in a number of Lewy bodies and in dystrophic neurites. Importantly, there was a spatial co-occurrence of pGlu79-α-synuclein with the enzyme QC in the human SN complex and a defined association of QC with neuropathological structures. We conclude that QC catalyzes the formation of oligomer-prone pGlu79-α-synuclein in human synucleinopathies, which may—in analogy to pGlu-Aβ peptides in Alzheimer’s disease—act as a seed for pathogenic protein aggregation.
CRIS-Team Scopus Importer:2021-08-06
Keywords: Animal models; Dementia with Lewy bodies; Glutaminyl cyclase; Parkinson’s disease; Post-translational modification; Substantia nigra; α-Synuclein

Agonist binding and g protein coupling in histamine h2 receptor: A molecular dynamics study - Conrad, Marcus; Söldner, Christian; Miao, Yinglong; Sticht, Heinrich (International Journal of Molecular Sciences, 2020)
The histamine H2 receptor (H2 R) plays an important role in the regulation of gastric acid secretion. Therefore, it is a main drug target for the treatment of gastroesophageal reflux or peptic ulcer disease. However, there is as of yet no 3D-structural information available hampering a mechanistic understanding of H2 R. Therefore, we created a model of the histamine-H2 R-Gs complex based on the structure of the ternary complex of the β2-adrenoceptor and investigated the conformational stability of this active GPCR conformation. Since the physiologically relevant motions with respect to ligand binding and conformational changes of GPCRs can only partly be assessed on the timescale of conventional MD (cMD) simulations, we also applied metadynamics and Gaussian accelerated molecular dynamics (GaMD) simulations. A multiple walker metadynamics simulation in combination with cMD was applied for the determination of the histamine binding mode. The preferential binding pose detected is in good agreement with previous data from site directed mutagenesis and provides a basis for rational ligand design. Inspection of the H2 R-Gs interface reveals a network of polar interactions that may contribute to H2 R coupling selectivity. The cMD and GaMD simulations demonstrate that the active conformation is retained on a µs-timescale in the ternary histamine-H2 R-Gs complex and in a truncated complex that contains only Gs helix α5 instead of the entire G protein. In contrast, histamine alone is unable to stabilize the active conformation, which is in line with previous studies of other GPCRs.
CRIS-Team Scopus Importer:2020-09-18
Keywords: G protein-coupled receptors (GPCRs); G; Gastric acid related diseases; Gaussian accelerated simulations (GaMD); Ligand binding mode; Metadynamics; Molecular dynamics simulations; Receptor–ligand interactions; Ternary complex

A Homozygous Mutation in GPT2 Associated with Nonsyndromic Intellectual Disability in a Consanguineous Family from Costa Rica - Lobo-Prada, Tanya; Sticht, Heinrich; Bogantes-Ledezma, Sixto; Ekici, Arif Bülent; Uebe, Steffen; Reis, André; Leal, Alejandro (JIMD reports, 2017)
Intellectual disability is a highly heterogeneous disease that affects the central nervous system and impairs patients' ability to function independently. Despite multiples genes involved in the etiology of disease, most of the genetic background is yet to be discovered. We used runs of homozygosity and exome sequencing to study a large Costa Rican family with four individuals affected with severe intellectual disability and found a novel homozygous missense mutation, p. 96G>R, c. 286G>A, in all affected individuals. This gene encodes for a pyridoxal enzyme involved in the production of the neurotransmitter glutamate and is highly expressed in the white matter of brain and cerebellum. Protein modeling of GPT2 predicted that the mutation is located in a loop where the substrate binds to the active site of the enzyme, therefore, suggesting that the catalytic activity is impaired. With our report of a second mutation we fortify the importance of GPT2 as a novel cause of autosomal recessive nonsyndromic intellectual disability and support the premise that GPT2 is highly important for the neurodevelopment of the central nervous system.The mutation p. 96G>R c. 286G>A in GPT2, located in a loop where the substrate binds to the active site of the enzyme, fortifies the importance of GPT2 in the pathogenesis of nonsyndromic intellectual disability.
EVALuna2:9390

A huge left atrial mass "not a myxoma" - Strecker, Thomas; Ruemmele, Petra; Seitz, Tatjana; Nooh, Ehab (Cardiology Journal, 2017)
N/A.
EVALuna2:35101

A human periodontal ligament fibroblast cell line as a new model to study periodontal stress - Weider, Matthias; Schröder, Agnes; Docheva, Denitsa; Rodrian, Gabriele; Enderle, Isabel; Seidel, Corinna Lesley; Andreev, Darja; Wegner, Michael; Bozec, Aline; Deschner, James; Kirschneck, Christian; Proff, Peter; et al. (International Journal of Molecular Sciences, 2020)
The periodontal ligament (PDL) is exposed to different kinds of mechanical stresses such as bite force or orthodontic tooth movement. A simple and efficient model to study molecular responses to mechanical stress is the application of compressive force onto primary human periodontal ligament fibroblasts via glass disks. Yet, this model suffers from the need for primary cells from human donors which have a limited proliferative capacity. Here we show that an immortalized cell line, PDL-hTERT, derived from primary human periodontal ligament fibroblasts exhibits characteristic responses to glass disk-mediated compressive force resembling those of primary cells. These responses include induction and secretion of pro-inflammatory markers, changes in expression of extracellular matrix-reorganizing genes and induction of genes related to angiogenesis, osteoblastogenesis and osteoclastogenesis. The fact that PDL-hTERT cells can easily be transfected broadens their usefulness, as molecular gain- and loss-of-function studies become feasible.
CRIS-Team Scopus Importer:2020-11-13
Keywords: Bone remodeling; Cell culture techniques; Mechanical loading; Orthodontic tooth movement

Alkali ion influence on structure and stability of fibrillar amyloid-beta oligomers - Huraskin, Danyil; Horn, Anselm (Journal of Molecular Modeling, 2019)
Alzheimer's disease is characterized by the aggregation of Amyloid-beta (A beta) peptide into oligomers, fibrils and plaques. Many factors influencing this process as well as the stability of the various A beta aggregates are known to date, and include the concentration and type of metal ions. Most experimental and theoretical studies have concentrated on heavy metal ions, like Fe2+, Zn2+, or Cu2+, while the smaller alkali ions Li+, Na+, and K+ have not gained much attention notwithstanding their role and ubiquity in physiological environments. In this work, we applied atomistic molecular dynamics simulations to investigate the potential role of these alkali ions in stabilizing fibrillar A beta oligomers of different size and topology, i.e., single and double filament systems comprising 3-24 peptide chains per filament. We find a pronounced difference on the molecular level in the interaction behavior with free carboxylate groups of the A beta oligomer: Li+ forms stable bridged interactions, whereas K+ interacts more transiently and lacks bridging. The behavior of Na+ is in between, so that this ion-protein interaction obeys the renowned Hofmeister series. These differences are also reflected in the ability of the alkali ions to stabilize the oligomer secondary structure. The stabilizing effect is most pronounced for the smaller fibrillar oligomers, suggesting that the type of alkali ion critically affects the initial stages of fibril formation. Our findings thus offer a molecular explanation for the observation that the polymorphisms of A beta fibril structures are caused by differences in the surrounding ionic environment.
CRIS-Team WoS Importer:2019-02-21

All purpose SOX: The many roles of Sox proteins in gene expression. - Wegner, Michael (International Journal of Biochemistry & Cell Biology, 2010)
Sox proteins are found in all metazoans and are active in many developmental processes. Their function as transcription factors is governed by their DNA-binding properties as much as by their interactions with other transcription factors and cofactors, and subject to modulation by posttranslational modifications. Although most Sox proteins predominantly function as transcriptional activators, there is also evidence for transcriptional repression and architectural roles. Further effects involve complex formation of Sox proteins with transcriptionally relevant factors off DNA. Sox proteins may be additionally active on the posttranscriptional level and are therefore remarkably versatile regulators of gene expression. © 2009 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.med.IB.LPCIPDBI.allpur
Keywords: Coactivator; High-mobility-group; Sry-box; Transactivation; Transcriptional repression

Alpha-synuclein activates BV2 microglia dependent on its aggregation state - Hoffmann, Alana; Ettle, Benjamin; Bruno, Ariane; Kulinich, Anna; Hoffmann, Anna-Carin; von Wittgenstein, Julia; Winkler, Jürgen; Xiang, Wei; Schlachetzki, Johannes (Biochemical and Biophysical Research Communications, 2016)
Synucleinopathies such as Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA) are defined by the presence of intracellular alpha-synuclein aggregates in neurons and/or oligodendrocytes. In addition, post mortem tissue analysis revealed profound changes in microglial morphology, indicating microglial activation and neuroinflammation. Thus, alpha-synuclein may directly activate microglia, leading to increased production of key pro-inflammatory cytokines like tumor necrosis factor-alpha (TNF-?) and interleukin-1beta (IL-1?), which in turn modulates the disease progression. The distinct alpha-synuclein species, which mediates the activation of microglia, is not well defined. We hypothesized that microglial activation depends on a specific aggregation state of alpha-synuclein. Here, we show that primarily human fibrillar alpha-synuclein increased the production and secretion of pro-inflammatory cytokines by microglial BV2 cells compared to monomeric and oligomeric alpha-synuclein. BV2 cells also preferentially phagocytosed fibrillar alpha-synuclein compared to alpha-synuclein monomers and oligomers. Microglial uptake of alpha-synuclein fibrils and the consequent activation were time- and concentration-dependent. Moreover, the degree of fibrillization determined the efficiency of microglial internalization. Taken together, our study highlights the specific crosstalk of distinct alpha-synuclein species with microglial cells.
EVALuna2:4715

Alpha-Synuclein and Its Role in Melanocytes - Rachinger, Nicole; Mittag, Nora; Böhme-Schäfer, Ines; Xiang, Wei; Kuphal, Silke; Boßerhoff, Anja Katrin (Cells, 2022)
Pigmentation is an important process in skin physiology and skin diseases and presumably also plays a role in Parkinson’s disease (PD). In PD, alpha-Synuclein (aSyn) has been shown to be involved in the pigmentation of neurons. The presynaptic protein is intensively investigated for its pathological role in PD, but its physiological function remains unknown. We hypothesized that aSyn is both involved in melanocytic differentiation and melanosome trafficking processes. We detected a strong expression of aSyn in human epidermal melanocytes (NHEMs) and observed its regulation in melanocytic differentiation via the microphthalmia-associated transcription factor (MITF), a central regulator of differentiation. Moreover, we investigated its role in pigmentation by performing siRNA experiments but found no effect on the total melanin content. We discovered a localization of aSyn to melanosomes, and further analysis of aSyn knockdown revealed an important role in melanocytic morphology and a reduction in melanosome release. Additionally, we found a reduction of transferred melanosomes in co-culture experiments of melanocytes and keratinocytes but no complete inhibition of melanosome transmission. In summary, this study highlights a novel physiological role of aSyn in melanocytic morphology and its so far unknown function in the pigment secretion in melanocytes.
CRIS-Team Scopus Importer:2022-07-15
Keywords: alpha-Synuclein; melanocytes; melanosomes; pigment transport; pigmentation

Altered glycan accessibility on native immunoglobulin G complexes in early rheumatoid arthritis and its changes during therapy - Stuemer, J.; Biermann, Mona; Knopf, Jasmin; Magorivska, I.; Kastbom, A.; Svaerd, A.; Janko, Christina; Bilyy, R.; Schett, Georg; Sjoewall, C.; Herrmann, Martin; Munoz, Luis Enrique; et al. (Clinical and Experimental Immunology, 2017)
The goal of this study was to investigate the glycosylation profile of native immunoglobulin (Ig)G present in serum immune complexes in patients with rheumatoid arthritis (RA). To accomplish this, lectin binding assays, detecting the accessibility of glycans present on IgG-containing immune complexes by biotinylated lectins, were employed. Lectins capturing fucosyl residues (AAL), fucosylated tri-mannose N-glycan core sites (LCA), terminal sialic acid residues (SNA) and O-glycosidically linked galactose/N-acetylgalactosamine (GalNac-L) were used. Patients with recent-onset RA at baseline and after 3-year follow-up were investigated. We found that native IgG was complexed significantly more often with IgM, C1q, C3c and C-reactive protein (CRP) in RA patients, suggesting alterations of the native structure of IgG. The total accessibility of fucose residues on captured immune complexes to the respective lectin was significantly higher in patients with RA. Moreover, fucose accessibility on IgG-containing immune complexes correlated positively with the levels of antibodies to cyclic citrullinated peptides (anti-CCP). We also observed a significantly higher accessibility to sialic acid residues and galactose/GalNAc glyco-epitopes in native complexed IgG of patients with RA at baseline. While sialic acid accessibility increased during treatment, the accessibility of galactose/GalNAc decreased. Hence, successful treatment of RA was associated with an increase in the SNA/GalNAc-L ratio. Interestingly, the SNA/GalNAc-L ratio in particular rises after glucocorticoid treatment. In summary, this study shows the exposure of glycans in native complexed IgG of patients with early RA, revealing particular glycosylation patterns and its changes following pharmaceutical treatment.
EVALuna2:13418

Alternative Wnt-signaling axis leads to a break of oncogene-induced senescence - Kluge, Viola; Kappelmann-Fenzl, Melanie; Fischer, Stefan; Zimmermann, Tom; Pommer, Michaela; Kuphal, Silke; Boßerhoff, Anja Katrin (Cell Death & Disease, 2024)
Oncogene-induced senescence (OIS) is an important process that suppresses tumor development, but the molecular mechanisms of OIS are still under investigation. It is known that BRAFV600E-mutated melanocytes can overcome OIS and develop melanoma, but the underlying mechanism is largely unknown. Using an established OIS model of primary melanocytes transduced with BRAFV600E, YAP activity was shown to be induced in OIS as well as in melanoma cells compared to that in normal epidermal melanocytes. This led to the assumption that YAP activation itself is not a factor involved in the disruption of OIS. However, its role and interaction partners potentially change. As Wnt molecules are known to be important in melanoma progression, these molecules were the focus of subsequent studies. Interestingly, activation of Wnt signaling using AMBMP resulted in a disruption of OIS in BRAFV600E-transduced melanocytes. Furthermore, depletion of Wnt6, Wnt10b or β-catenin expression in melanoma cells resulted in the induction of senescence. Given that melanoma cells do not exhibit canonical Wnt/β-catenin activity, alternative β-catenin signaling pathways may disrupt OIS. Here, we discovered that β-catenin is an interaction partner of YAP on DNA in melanoma cells. Furthermore, the β-catenin–YAP interaction changed the gene expression pattern from senescence-stabilizing genes to tumor-supportive genes. This switch is caused by transcriptional coactivation via the LEF1/TEAD interaction. The target genes with binding sites for LEF1 and TEAD are involved in rRNA processing and are associated with poor prognosis in melanoma patients. This study revealed that an alternative YAP-Wnt signaling axis is an essential molecular mechanism leading to OIS disruption in melanocytes. (Figure presented.).
CRIS-Team Scopus Importer:2024-03-01

AM1*parameters for phosphorus, sulfur and chlorine - Winget, Paul; Horn, Anselm; Martin, Bodo; Clark, Timothy; et al. (Journal of Molecular Modeling, 2003)
An extension of the AM1 semiempirical molecular orbital technique, AM1*, is introduced. AM1* uses AM1 parameters and theory unchanged for the elements H, C, N, O and F. The elements P, S and Cl have been reparameterized using an additional set of d orbitals in the basis set and with two-center core-core parameters, rather than the Gaussian functions used to modify the core-core potential in AM1. Voityuk and Rosch's AM1(d) parameters have been adopted unchanged for AM1* with the exception that new core-core parameters are defined for Mo-P, Mo-S and Mo-Cl interactions. Thus, AM1* gives identical results to AM1 for compounds with only H, C, N, O, and F, AM1(d) for compounds containing Mo, H, C, N, O and F only, but differs for molybdenum compounds containing P, S or Cl. The performance and typical errors of AM1* are discussed.
Keywords: semiempirical parameterization; AM1; NDDO

A matter of identity: transcriptional control in oligodendrocytes. - Wegner, Michael (Journal of Molecular Neuroscience, 2008)
UnivIS-Import:2015-03-09:Pub.2008.med.IB.LPCIPDBI.amatte

AMBER force-field parameters for phosphorylated amino acids in different protonation states: phosphoserine, phosphothreonine, phosphotyrosine, and phosphohistidine. - Homeyer, Nadine; Horn, Anselm; Lanig, Harald; Sticht, Heinrich (Journal of Molecular Modeling, 2006)
We report a consistent set of AMBER force-field parameters for the most common phosphorylated amino acids, phosphoserine, phosphothreonine, phosphotyrosine, and phosphohistidine in different protonation states. The calculation of atomic charges followed the original restrained electrostatic potential fitting procedure used to determine the charges for the parm94/99 parameter set, taking alpha-helical and beta-strand conformations of the corresponding ACE-/NME-capped model peptide backbone into account. Missing force-field parameters were taken directly from the general AMBER force field (gaff) and the parm99 data set with minor modifications, or were newly generated based on ab initio calculations for model systems. Final parameters were validated by geometry optimizations and molecular-dynamics simulations. Template libraries for the phosphorylated amino acids in Leap format and corresponding frcmod parameter files are made available. [Figure: see text].

A Metadynamics-Based Protocol for the Determination of GPCR-Ligand Binding Modes - Söldner, Christian; Horn, Anselm; Sticht, Heinrich (International Journal of Molecular Sciences, 2019)
G protein-coupled receptors (GPCRs) are a main drug target and therefore a hot topic in pharmaceutical research. One important prerequisite to understand how a certain ligand affects a GPCR is precise knowledge about its binding mode and the specific underlying interactions. If no crystal structure of the respective complex is available, computational methods can be used to deduce the binding site. One of them are metadynamics simulations which have the advantage of an enhanced sampling compared to conventional molecular dynamics simulations. However, the enhanced sampling of higher-energy states hampers identification of the preferred binding mode. Here, we present a novel protocol based on clustering of multiple walker metadynamics simulations which allows identifying the preferential binding mode from such conformational ensembles. We tested this strategy for three different model systems namely the histamine H1 receptor in combination with its physiological ligand histamine, as well as the β 2 adrenoceptor with its agonist adrenaline and its antagonist alprenolol. For all three systems, the proposed protocol was able to reproduce the correct binding mode known from the literature suggesting that the approach can more generally be applied to the prediction of GPCR ligand binding in future.
CRIS-Team Scopus Importer:2019-05-17
Keywords: clustering; G protein-coupled receptors (GPCRs); ligand binding modes; metadynamics simulations; molecular dynamics simulations; receptor-ligand interactions

Amino-Terminal Processing of Helicobacter pylori Serine Protease HtrA: Role in Oligomerization and Activity Regulation - Albrecht, Nicole; Tegtmeyer, Nicole; Sticht, Heinrich; Skorko-Glonek, Joanna; Backert, Steffen (Frontiers in Microbiology, 2018)
The HtrA family of serine proteases is found in most bacteria, and plays an essential role in the virulence of the gastric pathogen Helicobacter pylori. Secreted H. pylori HtrA (HtrA(Hp)) cleaves various junctional proteins such as E-cadherin disrupting the epithelial barrier, which is crucial for bacterial transmigration across the polarized epithelium. Recent studies indicated the presence of two characteristic HtrAHp forms of 55 and 52 kDa (termed p55 and p52, respectively), in worldwide strains. In addition, p55 and p52 were produced by recombinant HtrA(Hp), indicating auto-cleavage. However, the cleavage sites and their functional importance are yet unclear. Here, we determined the amino-terminal ends of p55 and p52 by Edman sequencing. Two proteolytic cleavage sites were identified (H46/D47 and K50/D51). Remarkably, the cleavage site sequences are conserved in HtrA(Hp) from worldwide isolates, but not in other Gram-negative pathogens, suggesting a highly specific assignment in H. pylori. We analyzed the role of the amino-terminal cleavage sites on activity, secretion and function of HtrA(Hp). Three-dimensional modeling suggested a trimeric structure and a role of amino-terminal processing in oligomerization and regulation of proteolytic activity of HtrA(Hp). Furthermore, point and deletion mutants of these processing sites were generated in the recently reported Campylobacter jejuni 1 htrA/htrA(Hp) genetic complementation system and the minimal sequence requirements for processing were determined. Polarized Caco-2 epithelial cells were infected with these strains and analyzed by immunofluorescence microscopy. The results indicated that HtrA(Hp) processing strongly affected the ability of the protease to disrupt the E-cadherin-based cell-to-cell junctions. Casein zymography confirmed that the amino-terminal region is required for maintaining the proteolytic activity of HtrA(Hp). Furthermore, we demonstrated that this cleavage influences the secretion of HtrA(Hp) in the extracellular space as an important prerequisite for its virulence activity. Taken together, our data demonstrate that amino-terminal cleavage of HtrA(Hp) is conserved in this pathogen and affects oligomerization and thus, secretion and regulatory activities, suggesting an important role in the pathogenesis of H. pylori.
EVALuna2:35494

A molecular analysis of the Yemenite deaf-blind hypopigmentation syndrome: Sox10 dysfunction causes different neurocristopathies - Wegner, Michael; et al. (Human Molecular Genetics, 1999)
The Yemenite deaf-blind hypopigmentation syndrome was first observed in a Yemenite sister and brother showing cutaneous hypopigmented and hyperpigmented spots and patches, microcornea, coloboma and severe hearing loss. A second case, observed in a girl with similar skin symptoms and hearing loss but without microcornea or coloboma, was reported as a mild form of this syndrome. Here we show that a SOX10 missense mutation is responsible for the mild form, resulting in a loss of DNA binding of this transcription factor. In contrast, no SOX10 alteration could be found in the other, severe case of the Yemenite deaf-blind hypopigmentation syndrome. Based on genetic, clinical, molecular and functional data, we suggest that these two cases represent two different syndromes. Moreover, as mutations of the SOX10 transcription factor were previously described in Waardenburg-Hirschsprung disease, these results show that SOX10 mutations cause various types of neurocristopathy.
UnivIS-Import:2015-03-05:Pub.1999.med.IB.LPCIPDBI.amolec

A molecular model for the differential activation of STAT3 and STAT6 by the herpesviral oncoprotein tip - Mazumder, Eman Dey; Jardin, Christophe; Vogel, Benjamin; Heck, Elke; Scholz, Brigitte; Lengenfelder, Doris; Sticht, Heinrich; Enßer, Armin (PLoS ONE, 2012)
Constitutive STAT signaling provides growth promoting signals in many forms of malignancy. We performed molecular modeling and molecular dynamics studies of the interaction between the regulatory Src homology 2 (SH2) domains of STAT3 and 6 with phosphorylated peptides of the herpesviral oncoprotein Tip, which facilitates Src kinase mediated STAT-activation and T cell proliferation. The studies give insight into the ligand binding specificity of the STAT SH2 domains and provide the first model for the differential activation of STAT3 or STAT6 by two distinct regions of the viral Tip protein. The biological relevance of the modeled interactions was then confirmed by activation studies using corresponding recombinant oncoproteins, and finally by respective recombinant viruses. The functional data give experimental validation of the molecular dynamics study, and provide evidence for the involvement of STAT6 in the herpesvirus induced T cell proliferation.
EVALuna2:8146

AMPA-receptor specific biogenesis complexes control synaptic transmission and intellectual ability - Brechet, Aline; Buchert, Rebecca; Schwenk, Jochen; Boudkkazi, Sami; Zolles, Gerd; Siquier-Pernet, Karine; Schaber, Irene; Bildl, Wolfgang; Saadi, Abdelkrim; Bole-Feysot, Christine; Nitschke, Patrick; Reis, André; et al. (Nature Communications, 2017)
AMPA-type glutamate receptors (AMPARs), key elements in excitatory neurotransmission in the brain, are macromolecular complexes whose properties and cellular functions are determined by the co-assembled constituents of their proteome. Here we identify AMPAR complexes that transiently form in the endoplasmic reticulum (ER) and lack the core-subunits typical for AMPARs in the plasma membrane. Central components of these ER AMPARs are the proteome constituents FRRS1l (C9orf4) and CPT1c that specifically and cooperatively bind to the pore-forming GluA1-4 proteins of AMPARs. Bi-allelic mutations in the human FRRS1L gene are shown to cause severe intellectual disability with cognitive impairment, speech delay and epileptic activity. Virus-directed deletion or overexpression of FRRS1l strongly impact synaptic transmission in adult rat brain by decreasing or increasing the number of AMPARs in synapses and extra-synaptic sites. Our results provide insight into the early biogenesis of AMPARs and demonstrate its pronounced impact on synaptic transmission and brain function.
EVALuna2:9374

Amphiregulin Regulates Melanocytic Senescence - Pommer, Michaela; Kuphal, Silke; Boßerhoff, Anja Katrin (Cells, 2021)
Oncogene-induced senescence (OIS) is a decisive process to suppress tumor development, but the molecular details of OIS are still under investigation. Using an established OIS model of primary melanocytes transduced with BRAF V600E and compared to control cells, amphiregulin (AREG) was shown to be induced. In addition, AREG expression was observed in nevi, which by definition, are senescent cell clusters, compared to melanocytes. Interestingly, treatment of melanocytes with recombinant AREG did induce senescence. This led to the assumption that extracellular AREG has an important function in this process. Inhibition of the epidermal growth factor receptor (EGFR) using Gefitinib identified AREG as one of EGFR ligands responsible for senescence. Furthermore, depletion of AREG expression in senescent BRAF V600E melanocytes resulted in a significant reduction of senescent melanocytes. This study reveals AREG as an essential molecular component of signaling pathways leading to senescence in melanocytes.
CRIS-Team Scopus Importer:2021-03-05
Keywords: amphiregulin; AREG; normal human primary melanocytes; OIS; oncogene induced senescence

A Multiple Piccolino-RIBEYE Interaction Supports Plate-Shaped Synaptic Ribbons in Retinal Neurons - Müller, Tanja; Gierke, Kaspar; Joachimsthaler, Anneka; Sticht, Heinrich; Izsvak, Zsuzsanna; Hamra, F. Kent; Fejtová, Anna; Ackermann, Frauke; Garner, Craig C.; Kremers, Jan; Brandstätter, Johann Helmut; Regus-Leidig, Hanna (Journal of Neuroscience, 2019)
Active zones at chemical synapses are highly specialized sites for the regulated release of neurotransmitters. Despite a high degree of active zone protein conservation in vertebrates, every type of chemical synapse expresses a given set of protein isoforms and splice variants adapted to the demands on neurotransmitter release. So far, we know little about how specific active zone proteins contribute to the structural and functional diversity of active zones. In this study, we explored the nanodomain organization of ribbon-type active zones by addressing the significance of Piccolino, the ribbon synapse-specific splice variant of Piccolo, for shaping the ribbon structure. We followed up on previous results, which indicated that rod photoreceptor synaptic ribbons lose their structural integrity in a knockdown of Piccolino. Here, we demonstrate an interaction between Piccolino and the major ribbon component RIBEYE that supports plate-shaped synaptic ribbons in retinal neurons. In a detailed ultrastructural analysis of three different types of retinal ribbon synapses in Piccolo/Piccolino-deficient male and female rats, we show that the absence of Piccolino destabilizes the superstructure of plate-shaped synaptic ribbons, although with variable manifestation in the cell types examined. Our analysis illustrates how the expression of a specific active zone protein splice variant (e.g., Piccolino) contributes to structural diversity of vertebrate active zones.
CRIS-Team WoS Importer:2019-04-12

A mutation in the β-subunit of ENaC identified in a patient with cystic fibrosis-like symptoms has a gain-of-function effect - Rauh, Robert; Söll, Daniel; Härteis, Silke; Diakov, Alexei; Nesterov, Viatcheslav; Krüger, Bettina; Sticht, Heinrich; Korbmacher, Christoph (American Journal of Physiology-Lung Cellular and Molecular Physiology, 2013)
In some patients with atypical cystic fibrosis (CF), only one allele of the CF transmembrane conductance regulator (CFTR) gene is affected. Mutations of the epithelial sodium channel (ENaC) may contribute to the pathophysiology of the disease in these patients. To functionally characterize a mutation in the ?-subunit of ENaC (?V348M) recently identified in a patient with severe CF-like symptoms (Mutesa et al. 2009), we expressed wild-type (wt) ???ENaC or mutant ??V348M?ENaC in Xenopus laevis oocytes. The ?V348M mutation stimulated amiloride-sensitive whole-cell current (?I(ami)) by 40% but had no effect on surface expression or single-channel conductance of ENaC. Instead the mutation increased channel open probability (P(o)). Proteolytic activation of mutant ENaC by chymotrypsin was reduced compared with that of wt ENaC ( 3.0-fold vs. 4.2-fold), which is consistent with the increased baseline P(o) of mutant ENaC. Similarly, the ENaC activator S3969 stimulated mutant ENaC currents to a lesser degree (by 2.6-fold) than wt ENaC currents (by 3.5-fold). The gain-of-function effect of the ?V348M mutation was confirmed by whole-cell current measurements in HEK293 cells transiently transfected with wt or mutant ENaC. Computational channel modeling in combination with functional expression of different ?V348 mutants in oocytes suggests that the ?V348M mutation increases channel P(o) by destabilizing the closed channel state. Our findings indicate that the gain-of-function effect of the ?V348M mutation may contribute to CF pathophysiology by inappropriately increasing sodium and fluid absorption in the respiratory trac
EVALuna2:4483

A mutation of the epithelial sodium channel associated with atypical cystic fibrosis increases channel open probability and reduces Na+ self inhibition - Rauh, Robert; Diakov, Alexei; Tzschoppe, Anja; Korbmacher, Judit; Azad, Abul Kalam; Cuppens, Harry; Cassiman, Jean-Jaques; Dötsch, Jörg; Sticht, Heinrich; Korbmacher, Christoph (The Journal of Physiology, 2010)
Increased activity of the epithelial sodium channel (ENaC) in the respiratory airways contributes to the pathophysiology of cystic fibrosis (CF), a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. In some patients suffering from atypical CF a mutation can be identified in only one CFTR allele. We recently identified in this group of CF patients a heterozygous mutation (W493R) in the α-subunit of ENaC. Here, we investigate the functional effects of this mutation by expressing wild-type αβγENaC or mutant αW493RβγENaC in Xenopus oocytes. The αW493R mutation stimulated amiloride-sensitive whole-cell currents (ΔIami) by ∼4-fold without altering the single-channel conductance or surface expression of ENaC. As these data suggest that the open probability (Po) of the mutant channel is increased, we investigated the proteolytic activation of ENaC by chymotrypsin. Single-channel recordings revealed that chymotrypsin activated near-silent channels in outside-out membrane patches from oocytes expressing wild-type ENaC, but not in membrane patches from oocytes expressing the mutant channel. In addition, the αW493R mutation abolished Na+ self inhibition of ENaC, which might also contribute to its gain-of-function effects. We conclude that the αW493R mutation promotes constitutive activation of ENaC by reducing the inhibitory effect of extracellular Na+ and decreasing the pool of near-silent channels. The resulting gain-of-function phenotype of the mutant channel might contribute to the pathophysiology of CF in patients carrying this mutation. © 2010 The Authors. Journal compilation © 2010 The Physiological Society.
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Amyloid-? dimers in the absence of plaque pathology impair learning and synaptic plasticity - Mueller-Schiffmann, Andreas; Herring, Arne; Abdel-Hafiz, Laila; Chepkova, Aisa N.; Schaeble, Sandra; Wedel, Diana; Horn, Anselm; Sticht, Heinrich; Silva, Maria A. De Souza; Gottmann, Kurt; Sergeeva, Olga A.; Huston, Joseph P.; et al. (Brain, 2016)
Despite amyloid plaques, consisting of insoluble, aggregated amyloid-? peptides, being a defining feature of Alzheimer's disease, their significance has been challenged due to controversial findings regarding the correlation of cognitive impairment in Alzheimer's disease with plaque load. The amyloid cascade hypothesis defines soluble amyloid-? oligomers, consisting of multiple amyloid-? monomers, as precursors of insoluble amyloid-? plaques. Dissecting the biological effects of single amyloid-? oligomers, for example of amyloid-? dimers, an abundant amyloid-? oligomer associated with clinical progression of Alzheimer's disease, has been difficult due to the inability to control the kinetics of amyloid-? multimerization. For investigating the biological effects of amyloid-? dimers, we stabilized amyloid-? dimers by an intermolecular disulphide bridge via a cysteine mutation in the amyloid-? peptide (A?-S8C) of the amyloid precursor protein. This construct was expressed as a recombinant protein in cells and in a novel transgenic mouse, termed tgDimer mouse. This mouse formed constant levels of highly synaptotoxic soluble amyloid-? dimers, but not monomers, amyloid-? plaques or insoluble amyloid-? during its lifespan. Accordingly, neither signs of neuroinflammation, tau hyperphosphorylation or cell death were observed. Nevertheless, these tgDimer mice did exhibit deficits in hippocampal long-term potentiation and age-related impairments in learning and memory, similar to what was observed in classical Alzheimer's disease mouse models. Although the amyloid-? dimers were unable to initiate the formation of insoluble amyloid-? aggregates in tgDimer mice, after crossbreeding tgDimer mice with the CRND8 mouse, an amyloid-? plaque generating mouse model, A?-S8C dimers were sequestered into amyloid-? plaques, suggesting that amyloid-? plaques incorporate neurotoxic amyloid-? dimers that by themselves are unable to self-assemble. Our results suggest that within the fine interplay between different amyloid-? species, amyloid-? dimer neurotoxic signalling, in the absence of amyloid-? plaque pathology, may be involved in causing early deficits in synaptic plasticity, learning and memory that accompany Alzheimer's disease.
EVALuna2:26292

An AGO2 variant affects the function of miRNAs and influences the viability of melanoma cells - Linck-Paulus, L.; Kappelmann-Fenzl, M.; Meister, G.; Boßerhoff, Anja Katrin (EXPERIMENTAL DERMATOLOGY, 2022)
CRIS-Team WoS Importer:2022-03-04

Analyses of the similarity and difference of global gene expression profiles in cortex regions of three neurodegenerative diseases: sporadic Creutzfeldt-Jakob disease (sCJD), fatal familial insomnia (FFI), and Alzheimer's disease (AD) - Tian, Chan; Liu, Di; Xiang, Wei; Kretzschmar, Hans A.; Sun, Qing-Lan; Gao, Chen; Xu, Yin; Wang, Hui; Fan, Xue-Yu; Meng, Ge; Li, Wei; Dong, Xiao-Ping (Molecular Neurobiology, 2014)
Neurodegenerative disease is a general designation for the disorders that are progressive loss of structure or function and final death of neurons, including Alzheimer's, Parkinson's, Huntington's, prion diseases, etc. In this study, we comparatively analyzed 21 individual microarray data sets of the cortex tissues from 11 sporadic Creutzfeldt-Jakob disease (sCJD), 3 fatal familial insomnia (FFI), 3 Alzheimer's disease (AD), and 4 normal controls. After normalization, a collection of 730 differently expressed sets (DESets) were obtained by comparison of the data of three diseases with their original controls. Principal component analysis (PCA) showed a background-related distribution within the groups of FFI, AD, and normal control, but two apparently different subgroups within the group of sCJD were observed. Review of the clinical materials of 11 sCJD patients identified the difference in brain PrP(Sc) deposits between two subgroups. Hierarchical cluster analysis illustrated the relatively independent clusters of normal controls, FFIs, six sCJD cases (subgroup 1) with more PrP(Sc) deposits, respectively, while an overlapped cluster of five cases of sCJD2 (subgroup 2) with less PrP(Sc) deposits and AD patients. Despite of the presence of special gene expressions, many common features were found among those neurodegenerative diseases. The most commonly changed biological processes (BPs) were signal transduction, synaptic transmission, and neuropeptide signaling pathway. The most commonly changed pathways were MAPK signaling pathway, Parkinson's disease, and oxidative phosphorylation. Our data here provide the similarity and difference in global gene expressions among the patients with sCJD, FFI, and AD, which may help to understand the common mechanism of neurodegenerative diseases.
EVALuna2:4697

Analysis and biological relevance of advanced glycation end-products of DNA in eukaryotic cells - Breyer, Viola; Frischmann, Matthias; Bidmon, Clemens; Schemm, Annelen; Schiebel, Katrin; Pischetsrieder, Monika (Febs Journal, 2008)
Advanced glycation end-products (AGEs) of DNA are formed spontaneously by the reaction of carbonyl compounds such as sugars, methylglyoxal or dihydroxyacetone in vitro and in vivo. Little is known, however, about the biological consequences of DNA AGEs. In this study, a method was developed to determine the parameters that promote DNA glycation in cultured cells. For this purpose, the formation rate of N2-carboxyethyl-2′- deoxyguanosine (CEdG), a major DNA AGE, was measured in cultured hepatic stellate cells by liquid chromatography (LC)-MS/MS. In resting cells, a 1.7-fold increase of CEdG formation rate was observed during 14 days of incubation. To obtain insights into the functional consequences of DNA glycation, CEdG was introduced into a luciferase reporter gene vector and transfected into human embryonic kidney (HEK 293 T) cells. Gene activity was determined by chemiluminescence of the luciferase. Thus, CEdG adducts led to a dose-dependent and highly significant decrease in protein activity, which is caused by loss of functionality of the luciferase in addition to reduced transcription of the gene. When the CEdG-modified vector was transformed into Escherichia coli, a loss of ampicillin resistance was observed in comparison to transformation with the unmodified plasmid. These results indicate that CEdG accumulates in the genomic DNA of resting cells, which could lead to diminished protein activity. © 2008 The Authors.
UnivIS-Import:2015-03-09:Pub.2008.nat.dchph.llmch.analys
Keywords: Advanced glycation end-products; DNA; Eukaryotic cells; Maillard reaction; N

Analysis of amino acid residues in the predicted transmembrane pore influencing transport kinetics of the hepatic drug transporter organic anion transporting polypeptide 1B1 (OATP1B1) - Gruetz, Moritz; Sticht, Heinrich; Gläser, Hartmut; Fromm, Martin; König, Jörg (BBA - Biochimica et Biophysica Acta, 2016)
The hepatic uptake transporters OATP1B1 (SLCO1B1) and OATP1B3 (SLCO1B3) mediate the uptake of endogenous metabolites and drugs from blood into hepatocytes. Alterations of transport function are accompanied with variations in drug plasma concentrations and the risk of adverse drug effects. Thus, knowledge on amino acids determining substrate recognition or transport kinetics are important to predict alterations in transport kinetics. Therefore, we analyzed the charged amino acids His54 and Tyr169, both located at the extracellular entry of the predicted transmembrane pore of OATP1B1. Based on a computational analysis we established HEK293 cell lines overexpressing the mutant OATP1B1 proteins HEK-OATP1B1p.H54Q, -p.H54A, -p.Y169H and -p.Y169A and analyzed protein expression, localization and transport kinetics of the four OATP1B1 substrates bromosulfophthalein, estradiaol-17?-glucuronide, taurocholate and pravastatin. Consequences on transport were detected for all mutants and these were different for each amino acid exchange and for each substrate tested. For example, the exchange H54Q resulted in reduced transport for BSP (78% of wildtype OATP1B1 transport at 0.05?M, P<0.01) with reduced affinity to this substrate (Km value increases from 0.76?M to 8.04?M) but in stimulated E217?G transport (138% compared to wildtype transport at 10?M, P<0.001). Investigating amino acid exchanges located at the extracellular entry of the transport pore of the OATP1B1 protein we demonstrated that these residues are involved in modulating transport kinetics and this participation strongly depends on the substrate and not on the physicochemical character of the investigated amino acid.
EVALuna2:8698

Analysis of ectopic Sox9 expression in NG2 glia of the adult murine brain - Engler, Lisa; Wegner, Michael (GLIA, 2021)
CRIS-Team WoS Importer:2021-07-16

Analysis of Glucose Concentration in Melanoma cells under physiological and nutrient-deficient Conditions - Herr, Felix; Schmidt, Sarah; Böhme, Ines; Boßerhoff, Anja Katrin (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2021)
CRIS-Team WoS Importer:2021-09-24

Analysis of Kruppel like factors in oligodendroglial differentiation and myelin gene expression - Bernhardt, Celine; Sock, Elisabeth; Wegner, Michael (GLIA, 2021)
CRIS-Team WoS Importer:2021-07-16

Analysis of lysozyme in cheese by immunocapture mass spectrometry - Schneider, Nadine; Becker, Cord-Michael; Pischetsrieder, Monika (Journal of Chromatography B-Analytical Technologies in the Biomedical and Life Sciences, 2010)
The enzyme lysozyme is used as a preservative to prevent late blowing of ripened cheese, caused by Clostridium tyrobutyricum. Since the enzyme is extracted from hen egg white, lysozyme has to be declared on food product labels as a potential allergen. Here, a method is reported that combines immunocapture purification and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis for the detection of lysozyme in cheese samples. Cheese extracts were treated with magnetic particles coated with a monoclonal antibody directed against lysozyme. After immunocapture purification, lysozyme was detected by MALDI-TOF-MS. The limit of detection of the assay was about 5 mg/kg lysozyme in cheese. The method reliably distinguished between cheese samples which had been produced with and without lysozyme. Thus, the novel assay allows the reliable, sensitive, and specific detection of lysozyme in a food matrix. The assay could be easily adapted to other target peptides and proteins in complex food matrices and, therefore, has a broad application potential, e.g. for the analysis of allergens. © 2009 Elsevier B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2010.nat.dchph.llmch.analys
Keywords: Cheese; Immunocapture mass spectrometry; Lysozyme; Matrix-assisted laser desorption/ionization mass spectrometry

ANALYSIS OF MOLECULAR MECHANISMS OF 5-FLUOROURACIL INDUCED STEATOSIS AND INFLAMMATION IN VITRO AND IN MICE - Sommer, J.; Mahli, A.; Freese, K.; Thasler, W.; Kuecuekoktay, F.; Boßerhoff, Anja Katrin; Mueller, M.; Hellerbrand, C. (2016)
EVALuna2:33709

Analysis of molecular mechanisms of 5-fluorouracil-induced steatosis and inflammation in vitro and in mice - Sommer, Judith; Mahli, Abdo; Freese, Kim; Schiergens, Tobias S.; Kuecuekoktay, Fulya Suzan; Teufel, Andreas; Thasler, Wolfgang E.; Mueller, Martina; Boßerhoff, Anja Katrin; Hellerbrand, Claus (Oncotarget, 2017)
Chemotherapy-associated steatohepatitis is attracting increasing attention because it heralds an increased risk of morbidity and mortality in patients undergoing surgery because of liver metastases. The aim of this study was to develop in vitro and in vivo models to analyze the pathogenesis of 5-fluorouracil (5-FU)-induced steatohepatitis.Therefore, primary human hepatocytes and HepG2 hepatoma cells were incubated with 5-FU at non-toxic concentrations up to 24 h. Furthermore, hepatic tissue of C57BL/6N mice was analyzed 24 h after application of a single 5-FU dose (200 mg/kg body weight). In vitro, incubation with 5-FU induced a significant increase of hepatocellular triglyceride levels. This was paralleled by an impairment of mitochondrial function and a dose- and time-dependently increased expression of fatty acid acyl-CoA oxidase 1 (ACOX1), which catalyzes the initial step for peroxisomal ?-oxidation. The latter is known to generate reactive oxygen species, and consequently, expression of the antioxidant enzyme heme oxygenase 1 (HMOX1) was significantly upregulated in 5-FU-treated cells, indicative for oxidative stress. Furthermore, 5-FU significantly induced c-Jun N-terminal kinase (JNK) activation and the expression of pro-inflammatory genes IL-8 and ICAM-1. Also in vivo, 5-FU significantly induced hepatic ACOX1 and HMOX1 expression as well as JNK-activation, pro-inflammatory gene expression and immune cell infiltration. In summary, we identified molecular mechanisms by which 5-FU induces hepatocellular lipid accumulation and inflammation. Our newly developed models can be used to gain further insight into the pathogenesis of 5-FU-induced steatohepatitis and to develop therapeutic strategies to inhibit its development and progression.
EVALuna2:4753

Analysis of naturally occurring mutations in the human uptake transporter NaCT important for bone and brain development and energy metabolism - Selch, Stefan; Chafai, Anja; Sticht, Heinrich; Birkenfeld, Andreas L.; Fromm, Martin; König, Jörg (Scientific Reports, 2018)
The human uptake transporter NaCT is important for human brain development, brain function and energy metabolism and mediates the uptake of citrate and other intermediates of the tricarboxylic acid cycle from blood into neurons and hepatocytes. Mutations in the SLC13A5 gene encoding NaCT are associated with epileptic encephalopathy. To gain more insights into the transport mechanisms we analyzed the functional consequences of mutations in the SLC13A5 gene on NaCT-mediated transport function. Using HEK293 cells expressing wild-type and eight mutated NaCT proteins, we investigated the mRNA and protein amount as well as the protein localization of all NaCT variants. Furthermore, the impact on NaCT-mediated citrate uptake was measured. In addition, a structural model of the transport pore was generated to rationalize the consequences of the mutations on a structural basis. We demonstrated that all proteins were synthesized with an identical molecular weight as the wild-type transporter but several mutations (NaCTp.G219R, -p.G219E, -p.T227M, -p.L420P and -p.L488P) lead to a complete loss of NaCT-mediated citrate transport. This loss of transport activity can be explained on the basis of the developed structural model. This model may help in the further elucidation of the transport mechanism of this important uptake transporter.
EVALuna2:34652

Analysis of Protein Glycation Products by MALDI-TOF/MS - Kislinger, Thomas; Humeny, Andreas; Becker, Cord-Michael; Peich, Carlo; Pischetsrieder, Monika (Annals of the New York Academy of Sciences, 2005)
Matrix-assisted laser desorption ionization-mass spectrometry with time-of-flight detection (MALDI-TOF/MS) is a promising tool to analyze advanced glycation end product (AGE)-modified proteins. The combination of soft ionisation (MALDI) with time-of-flight mass detection allows analysis of peptides and proteins of a molecular mass up to 300 kDa with minimal sample workup. Because the direct structural analysis of intact AGE proteins is not possible due to the formation of broad and poorly resolved peaks, peptide mapping was introduced into the analysis of AGE proteins by MALDI-TOF/MS, allowing site-specific analysis of defined AGEs. When methylglyoxal-modified lysozyme was subjected to MALDI-TOF/MS peptide mapping, methylimidazolone and argpyrimidine attached to the arginine residue and carboxyethyl (CEL) bound to the lysine were detected on peptideaa1-7 (KVFGRCE). In contrast, only one methylimidazolone was found on peptideaa8-35 (LAAAMKRHGLDNYRGYSLGNWVCAAKFE) and peptideaa120-129 (VQAWIRGCRL), respectively. The analysis of AGE protein, which had been incubated with glucose, revealed the presence of am Amadori product and a carboxymethyl residue (CML) on peptideaa1-7 and peptideaa8-35, as well as an imidazolone A on peptideaa120-129. Furthermore, the early Maillard reaction of lysozyme, which had been glycated by seven different sugars, was monitored by MALDI-TOF/MS peptide mapping. Finally, this approach was successfully applied for site- and product-specific relative quantification of AGEs. For example, kinetics of CML and Amadori product formation on peptide aa1-7, as well as imidazolone A formation on peptide aa120-129, were determined. © 2005 New York Academy of Sciences.
UnivIS-Import:2015-04-16:Pub.2005.nat.dchph.llmch.analys
Keywords: Advanced glycation end products; Maillard reaction; MALDI-TOF/MS; Mass spectrometry; Peptide mapping

Analysis of the expression pattern of the schizophrenia-risk and intellectual disability gene TCF4 in the developing and adult brain suggests a role in development and plasticity of cortical and hippocampal neurons - Jung, Matthias; Häberle, Benjamin; Tschaikowsky, Tristan; Wittmann, Marie-Theres; Balta, Elli-Anna; Stadler, Vivien-Charlott; Zweier, Christiane; Dörfler, Arnd; Gloeckner, Christian Johannes; Lie, Dieter Chichung (Molecular Autism, 2018)
Background: Haploinsufficiency of the class I bHLH transcription factor TCF4 causes Pitt-Hopkins syndrome (PTHS), a severe neurodevelopmental disorder, while common variants in the TCF4 gene have been identified as susceptibility factors for schizophrenia. It remains largely unknown, which brain regions are dependent on TCF4 for their development and function. Methods: We systematically analyzed the expression pattern of TCF4 in the developing and adult mouse brain. We used immunofluorescent staining to identify candidate regions whose development and function depend on TCF4. In addition, we determined TCF4 expression in the developing rhesus monkey brain and in the developing and adult human brain through analysis of transcriptomic datasets and compared the expression pattern between species. Finally, we morphometrically and histologically analyzed selected brain structures in Tcf4-haploinsufficient mice and compared our morphometric findings to neuroanatomical findings in PTHS patients. Results: TCF4 is broadly expressed in cortical and subcortical structures in the developing and adult mouse brain. The TCF4 expression pattern was highly similar between humans, rhesus monkeys, and mice. Moreover, Tcf4 haploinsufficiency in mice replicated structural brain anomalies observed in PTHS patients. Conclusion: Our data suggests that TCF4 is involved in the development and function of multiple brain regions and indicates that its regulation is evolutionary conserved. Moreover, our data validate Tcf4-haploinsufficient mice as a model to study the neurodevelopmental basis of PTHS.
EVALuna:34022

Analysis of the human SOX10 mutation Q377X in mice and its implications for genotype-phenotype correlation in SOX10-related human disease. - Truch, Kathrin; Arter, Juliane; Turnescu, Tanja; Weider, Matthias; Hartwig, Anna; Tamm, Ernst R.; Sock, Elisabeth; Wegner, Michael (Human Molecular Genetics, 2018)
UnivIS-Import:2018-09-11:Pub.2018.med.IB.LPCIPDBI.analys

Analysis of the peptide profile of milk and its changes during thermal treatment and storage - Meltretter, Jasmin; Schmidt, Alexander; Humeny, Andreas; Becker, Cord-Michael; Pischetsrieder, Monika (Journal of Agricultural and Food Chemistry, 2008)
In this study a new method was developed for analysis of the low molecular weight protein fraction of milk, allowing a simple and fast overview of the peptide profile of various milk samples. For this purpose, immobilized metal affinity chromatography (IMAC) was coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). By this technique, two major peptides in milk could be identified as fragments of alpha-s1-casein. During heat treatment of raw milk, five new peptides were generated, the origin of which could be assigned to the casein fraction. Storage experiments with extended shelf life milk at 4 degrees C did not show any changes in the peptide profile, whereas in ultra high temperature milk stored at room temperature, one peptide increased significantly, which was identified as the N-terminus of alpha-s1-casein. The peptide was assumed to be formed in an enzymatic reaction, which was confirmed in a storage experiment with sterilized milk. Analyses of different commercially available milk samples confirmed the results obtained with the heated and stored milk. Furthermore, differences in the peptide profiles of the samples, probably due to different cow breeds or lactation stages, were observed. These results establish IMAC prior to MALDI-TOF-MS as a valid tool for the rapid analysis of the peptide profile of milk.
Keywords: Milk; peptides; proteolysis; heat treatment; storage; immobilized metal affinity chromatography; matrix-assisted laser desorption/ionization mass pectrometry

Anconeus epitrochlearis muscle (epitrochlearisanconeus muscle; Musculus epitrochleoanconeus) with cubital tunnel syndrome – a rare but relevant clinical entity - Grüner, Jasmin; Paulsen, Friedrich; Barth, Anna; Horch, Raymund E. (Annals of Anatomy-Anatomischer Anzeiger, 2023)
Background: Compression of the ulnar nerve at the elbow within the cubital tunnel is related to the anatomical structures and is generally believed to be caused by Osborne's ligament (also known as the cubital retinaculum). However, in rare cases an anatomical variation of the developmental peculiarity of a remaining anconeus epitrochlearis muscle may be responsible for the disease. Methods: We present a series of five cases in which an anconeus epitrochlearis muscle was found as the cause of illness. Results: All patients presented with typical symptoms of numbness and tingling in the hand and ulnar fingers, and recurring pain as well as weakness of the ulnar innervated muscles. With neurophysiologically confirmed diminished nerve conduction velocity and unsuccessful conservative treatment, surgical decompression revealed an anconeus epitrochlearis muscle as the reason of compression. Full symptom relief was achieved immediately after the procedure in all cases. Conclusions: This article strives to call attention to this entity when diagnosing ulnar nerve compression. Myectomy and medial epicondylectomy is the preferred treatment option in such cases.
CRIS-Team Scopus Importer:2023-10-27
Keywords: Cubital tunnel syndrome; Musculus anconeus epitrochlearis; Musculus epitrochleoanconeus; Sulcus ulnaris

A New Fluorogenic Small-Molecule Labeling Tool for Surface Diffusion Analysis and Advanced Fluorescence Imaging of β-Site Amyloid Precursor Protein-Cleaving Enzyme 1 Based on Silicone Rhodamine: SiR-BACE1 - Karch, Sandra; Broichhagen, Johannes; Schneider, Julia; Boening, Daniel; Hartmann, Stephanie; Schmid, Benjamin; Tripal, Philipp; Palmisano, Ralf; Alzheimer, Christian; Johnsson, Kai; Huth, Tobias (Journal of Medicinal Chemistry, 2018)
β-site APP-cleaving enzyme 1 (BACE1) is a major player in the pathogenesis of Alzheimer's disease. Structural and functional fluorescence microscopy offers a powerful approach to learn about the physiology and pathophysiology of this protease. Up to now, however, common labeling techniques require genetic manipulation, use large antibodies, or are not compatible with live cell imaging. Fluorescent small molecules that specifically bind to the protein of interest can overcome these limitations. Herein, we introduce SiR-BACE1, a conjugate of the BACE1 inhibitor S-39 and SiR647, as a novel fluorogenic, tag-free, and antibody-free label for BACE1. We present its chemical development, characterize its photophysical and pharmacologic properties, and evaluate its behavior in solution, in overexpression systems, and in native brain tissue. We demonstrate its applicability in confocal, stimulated emission depletion and dynamic single-molecule microscopy. The first functional studies with SiR-BACE1 on the surface mobility of BACE1 revealed a markedly confined diffusion pattern.
EVALuna2:35761

A newly identified secreted larval antigen elicits basophil-dependent protective immunity against N. brasiliensis infection - Thuma, Natalie; Döhler, Daniela; Mielenz, Dirk; Sticht, Heinrich; Radtke, Daniel; Reimann, Lena; Warscheid, Bettina; Vöhringer, David (Frontiers in Immunology, 2022)
Hookworms infect more that 400 million people and cause significant socio-economic burden on endemic countries. The lack of efficient vaccines and the emergence of anthelminthic drug resistance are of major concern. Free-living hookworm larvae infect their hosts via the skin and live as adult worms in the small intestine where they feed on host tissue and blood. Excretory/secretory (E/S) products, released by helminths as they migrate through their host, are thought to play a key role in facilitating infection and successful establishment of parasitism. However, E/S products can also elicit protective immune responses that might be harnessed for vaccine development. By performing Western blots with serum of Nippostrongylus brasiliensis (Nb) infected mice as a model for human hookworm infection, we identified a largely overlapping set of IgG1- and IgE-reactive antigens in E/S from infective L3 stage larvae. Mass spectrometry analysis led to the identification of a new protein family with 6 paralogues in the Nb genome which we termed Nb-LSA1 for “Nippostrongylus brasiliensis larval secreted protein 1”. The recombinantly expressed 17 kDa family member Nb-LSA1a was recognized by antibodies in the serum of Nb immune mice. Immunization of mice with Nb-LSA1a in alum elicited a strong IgG1 response but no detectable antigen-specific IgE. Most importantly, immunized mice were largely protected against a challenge Nb infection. This effect was dependent on the presence of basophils and occurred before the parasites reached the intestine. Therefore, basophils appear to play a critical role for rapid control of infection with L3 stage larvae in mice immunized with a single secreted larval protein. A better understanding of basophil-mediated protective immunity and identification of potent larval antigens of human hookworms could help to develop promising vaccination strategies.
CRIS-Team Scopus Importer:2022-09-30
Keywords: basophils; CAP domain; hookworms; immunization; SCP/TAPS protein

A new printable alginate / hyaluronic acid / gelatin hydrogel suitable for biofabrication of in vitro and in vivo metastatic melanoma models - Schmid, Rafael; Schmidt, Sonja; Detsch, Rainer; Horder, Hannes; Blunk, Torsten; Schrüfer, Stefan; Schubert, Dirk W.; Fischer, Lena; Thievessen, Ingo; Heltmann-Meyer, Stefanie; Steiner, Dominik; Schneidereit, Dominik; et al. (Advanced Functional Materials, 2021)
Two-dimensional (2D) cancer models have been the standard for drug development over the past few years, but they frequently do not resemble in vivo properties adequately. 3D models are superior in many aspects and are, therefore, more similar to human pathophysiology. Over the past years, the emerging field of biofabrication has made significant advances, resulting in even more sophisticated 3D models. With this study, a hydrogel is created for biofabrication that is suitable for mimicking the tumor microenvironment in vitro and is further tested as a new vascularized melanoma model in vivo. The alginate/hyaluronic acid/gelatin bioink shows good shape-fidelity, high cell survival rates, and enables successful cultivation of melanoma cells and adipose-derived stem cells as well as cell differentiation in vitro. In vivo, in the arteriovenous loop model, it proves to be a unique method to study melanoma progression, tumor vascularization, and ultimately and reliably metastases in an isolated and controlled environment. These results show that this 3D model is very application-oriented for molecular research and therapy developmen

A New Printable Alginate/Hyaluronic Acid/Gelatin Hydrogel Suitable for Biofabrication of In Vitro and In Vivo Metastatic Melanoma Models - Schmid, Rafael; Schmidt, Sonja; Detsch, Rainer; Horder, Hannes; Blunk, Torsten; Schrüfer, Stefan; Schubert, Dirk W.; Fischer, Lena; Thievessen, Ingo; Heltmann-Meyer, Stefanie; Steiner, Dominik; Schneidereit, Dominik; et al. (Advanced Functional Materials, 2021)
Two-dimensional (2D) cancer models have been the standard for drug development over the past few years, but they frequently do not resemble in vivo properties adequately. 3D models are superior in many aspects and are, therefore, more similar to human pathophysiology. Over the past years, the emerging field of biofabrication has made significant advances, resulting in even more sophisticated 3D models. With this study, a hydrogel is created for biofabrication that is suitable for mimicking the tumor microenvironment in vitro and is further tested as a new vascularized melanoma model in vivo. The alginate/hyaluronic acid/gelatin bioink shows good shape-fidelity, high cell survival rates, and enables successful cultivation of melanoma cells and adipose-derived stem cells as well as cell differentiation in vitro. In vivo, in the arteriovenous loop model, it proves to be a unique method to study melanoma progression, tumor vascularization, and ultimately and reliably metastases in an isolated and controlled environment. These results show that this 3D model is very application-oriented for molecular research and therapy development.
CRIS-Team Scopus Importer:2021-10-22
Keywords: bioinks; metastasis; stem cells; tissue engineering; tumors

A new printable alginate / hyaluronic acid / gelatin hydrogel suitable for biofabrication of in vitro and in vivo metastatic melanoma models - Schmid, Rafael; Schmidt, Sonja; Detsch, Rainer; Horder, Hannes; Blunk, Torsten; Schrüfer, Stefan; Schubert, Dirk W.; Fischer, Lena; Thievessen, Ingo; Heltmann-Meyer, Stefanie; Steiner, Dominik; Schneidereit, Dominik; et al. (Advanced Functional Materials, 2022)

An information-theoretic classification of amino acids for the assessment of interfaces in protein-protein docking - Jardin, Christophe; Stefani, Arno; Eberhardt, Martin; Huber, Johannes; Sticht, Heinrich (Journal of Molecular Modeling, 2013)
Docking represents a versatile and powerful method to predict the geometry of protein-protein complexes. However, despite significant methodical advances, the identification of good docking solutions among a large number of false solutions still remains a difficult task. We have previously demonstrated that the formalism of mutual information (MI) from information theory can be adapted to protein docking, and we have now extended this approach to enhance its robustness and applicability. A large dataset consisting of 22,934 docking decoys derived from 203 different protein-protein complexes was used for an MI-based optimization of reduced amino acid alphabets representing the protein-protein interfaces. This optimization relied on a clustering analysis that allows one to estimate the mutual information of whole amino acid alphabets by considering all structural features simultaneously, rather than by treating them individually. This clustering approach is fast and can be applied in a similar fashion to the generation of reduced alphabets for other biological problems like fold recognition, sequence data mining, or secondary structure prediction. The reduced alphabets derived from the present work were converted into a scoring function for the evaluation of docking solutions, which is available for public use via the web service score-MI: http://score-MI.biochem.uni-erlangen.de.
EVALuna2:26278

An inhibitory peptide derived from the α-subunit of the epithelial sodium channel (ENaC) shows a helical conformation - Härteis, Silke; Schaal, Daniel; Brauer, Felix; Brueschke, Stefan; Schweimer, Kristian; Rauh, Robert; Sticht, Heinrich; Roesch, Paul; Schwarzinger, Stephan; Korbmacher, Christoph (Cellular Physiology and Biochemistry, 2012)
Proteolytic activation of the heteromeric epithelial sodium channel (ENaC) is thought to involve the release of inhibitory peptides from the extracellular domains of its ?- and ?-subunit. Recently, we demonstrated that an ?-13-mer peptide, corresponding to a putative inhibitory region within the extracellular domain of human ?ENaC, inhibits human ???ENaC. The aim of the present study was to investigate the structural basis of the inhibitory effect of this ?-13-mer peptide. Analysis of the peptide by replica exchange molecular dynamics method, circular dichroism spectroscopy, nuclear magnetic resonance spectroscopy, and molecular dynamics simulations suggested that a helical turn at the carboxy-terminus is the preferred conformational state of the ?-13-mer peptide. From this we predicted that a specific mutation (leucine 188 to alanine) should have a strong effect on the conformational preferences of the peptide. To functionally test this, we compared the effect of the wild-type ?-13-mer with that of a mutant ?-L188A-13-mer on ENaC currents in Xenopus laevis oocytes heterologously expressing human ???ENaC. We demonstrated that replacing the leucine 188 by alanine abolished the inhibitory effect of the ?-13-mer peptide on ENaC. These findings suggest that a helical conformation in its carboxyterminal part is functionally important to mediate ENaC inhibition by the ?-13-mer peptide. However, high resolution structural information on the complex of the inhibitory ?ENaC peptide and the channel are needed to confirm this conclusio
EVALuna2:4484

An integrative network-driven pipeline for systematic identification of lncRNA-associated regulatory network motifs in metastatic melanoma - Singh, Nivedita; Eberhardt, Martin; Wolkenhauer, Olaf; Vera, Julio; Gupta, Shailendra K. (BMC Bioinformatics, 2020)
BACKGROUND: Melanoma phenotype and the dynamics underlying its progression are determined by a complex interplay between different types of regulatory molecules. In particular, transcription factors (TFs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) interact in layers that coalesce into large molecular interaction networks. Our goal here is to study molecules associated with the cross-talk between various network layers, and their impact on tumor progression. RESULTS: To elucidate their contribution to disease, we developed an integrative computational pipeline to construct and analyze a melanoma network focusing on lncRNAs, their miRNA and protein targets, miRNA target genes, and TFs regulating miRNAs. In the network, we identified three-node regulatory loops each composed of lncRNA, miRNA, and TF. To prioritize these motifs for their role in melanoma progression, we integrated patient-derived RNAseq dataset from TCGA (SKCM) melanoma cohort, using a weighted multi-objective function. We investigated the expression profile of the top-ranked motifs and used them to classify patients into metastatic and non-metastatic phenotypes. CONCLUSIONS: The results of this study showed that network motif UCA1/AKT1/hsa-miR-125b-1 has the highest prediction accuracy (ACC = 0.88) for discriminating metastatic and non-metastatic melanoma phenotypes. The observation is also confirmed by the progression-free survival analysis where the patient group characterized by the metastatic-type expression profile of the motif suffers a significant reduction in survival. The finding suggests a prognostic value of network motifs for the classification and treatment of melanoma.
CRIS-Team Scopus Importer:2020-08-07
Keywords: Data integration; LncRNA; Melanoma; MiRNA; Network approach; RNA motif; Systems biology; Transcription factor

An iso-α-acid-rich extract from hops (Humulus lupulus) attenuates acute alcohol-induced liver steatosis in mice - Hege, Marianne; Jung, Finn; Sellmann, Cathrin; Jin, Chengjun; Ziegenhardt, Doreen; Hellerbrand, Claus; Bergheim, Ina (Nutrition, 2018)
OBJECTIVE: Results of in vitro and in vivo studies suggest that consumption of beer is less harmful for the liver than consumption of spirits. It also has been suggested that secondary plant compounds derived from hops such as xanthohumol or iso-α-acids may have beneficial effects on the development of liver diseases of various etiologies. The aim of this study was to determine whether iso-α-acids consumed in doses achieved by "normal" beer consumption have beneficial effects on health. METHODS: Female C57 Bl/6 J mice, pretreated for 4 d with an iso-α-acid-rich extract (∼30% iso-α-acids from hops, 0.75 mg/kg body weight), were fed one bolus of ethanol (6 g/kg body weight intragastric) or an iso-caloric maltodextrin solution. Markers of liver damage, toll-like receptor-4 signaling, and lipid peroxidation were determined. Furthermore, the effect of isohumulone on the lipopolysaccharide-dependent activation of J774 A.1 macrophages, used as a model of Kupffer cells, was determined. RESULTS: In the liver, acute ethanol administration led to a significant accumulation of fat (∼10-fold), which was accompanied by significantly higher inducible nitric oxide synthase protein level, elevated nitric oxide production, and increased plasminogen activator inhibitor 1 protein concentration when compared to controls. In mice pretreated with iso-α-acids, these effects of alcohol were markedly attenuated. Pretreatment of J774 A.1 macrophages with isohumulone significantly attenuated lipopolysaccharide-induced mRNA expression of inducible nitric oxide synthase and interleukin-6 as well as the release of nitric oxide. CONCLUSION: Taken together, iso-α-acids markedly attenuated the development of acute alcohol-induced damage in mice.
EVALuna2:35802

A novel D-amino acid peptide with therapeutic potential (ISAD1) inhibits aggregation of neurotoxic disease-relevant mutant Tau and prevents Tau toxicity in vitro - Aillaud, Isabelle; Kaniyappan, Senthilvelrajan; Chandupatla, Ram Reddy; Ramirez, Lisa Marie; Alkhashrom, Sewar; Eichler, Jutta; Horn, Anselm; Zweckstetter, Markus; Mandelkow, Eckhard; Sticht, Heinrich; Funke, Susanne Aileen (Alzheimer's Research and Therapy, 2022)
Background Alzheimer's disease (AD), the most common form of dementia, is a progressive neurodegenerative disorder that mainly affects older adults. One of the pathological hallmarks of AD is abnormally aggregated Tau protein that forms fibrillar deposits in the brain. In AD, Tau pathology correlates strongly with clinical symptoms, cognitive dysfunction, and neuronal death. Methods We aimed to develop novel therapeutic D-amino acid peptides as Tau fibrillization inhibitors. It has been previously demonstrated that D-amino acid peptides are protease stable and less immunogenic than L-peptides, and these characteristics may render them suitable for in vivo applications. Using a phage display procedure against wild type full-length Tau (Tau(FL)), we selected a novel Tau binding L-peptide and synthesized its D-amino acid version ISAD1 and its retro inversed form, ISAD1rev, respectively. Results While ISAD1rev inhibited Tau aggregation only moderately, ISAD1 bound to Tau in the aggregation-prone PHF6 region and inhibited fibrillization of Tau(FL), disease-associated mutant full-length Tau (Tau(FL Delta K), Tau(FL-A152T), Tau(FL-P301L)), and pro-aggregant repeat domain Tau mutant (Tau(RD Delta K)). ISAD1 and ISAD1rev induced the formation of large high molecular weight Tau(FL) and Tau(RD Delta K) oligomers that lack proper Thioflavin-positive beta-sheet conformation even at lower concentrations. In silico modeling of ISAD1 Tau interaction at the PHF6 site revealed a binding mode similar to those known for other PHF6 binding peptides. Cell culture experiments demonstrated that ISAD1 and its inverse form are taken up by N2a-Tau(RD Delta K) cells efficiently and prevent cytotoxicity of externally added Tau fibrils as well as of internally expressed Tau(RD Delta K). Conclusions ISAD1 and related peptides may be suitable for therapy development of AD by promoting off-pathway assembly of Tau, thus preventing its toxicity.
CRIS-Team WoS Importer:2022-01-28

A novel human stem cell model for Coffin-Siris syndrome-like syndrome reveals the importance of SOX11 dosage for neuronal differentiation and survival - Turan, Sören; Börstler, Tom; Kavyanifar, Atria; Loskarn, Sandra; Reis, André; Winner, Beate; Lie, Dieter Chichung (Human Molecular Genetics, 2019)
The SOXC transcription factors Sox4, Sox11 and Sox12, are critical neurodevelopmental regulators that are thought to function in a highly redundant fashion. Surprisingly, heterozygous missense mutations or deletions of SOX11 were recently detected in patients with Coffin-Siris syndrome-like syndrome (CSSLS), a neurodevelopmental disorder associated with intellectual disability, demonstrating that in humans SOX11 haploinsufficiency cannot be compensated and raising the question of the function of SOX11 in human neurodevelopment. Here, we describe the generation of SOX11(+/-) heterozygous human embryonic stem cell (hESC) lines by CRISPR/Cas9 genome engineering. SOX11 haploinsufficiency impaired the generation of neurons and resulted in a proliferation/differentiation imbalance of neural precursor cells and enhanced neuronal cell death. Using the SOX11(+/-) hESC model we provide for the first time experimental evidence that SOX11 haploinsufficiency is sufficient to impair key processes of human neurodevelopment, giving a first insight into the pathophysiology of CSSLS and SOX11 function in human neurodevelopment.
CRIS-Team WoS Importer:2019-11-12

A novel splice variant of Argonaut 2 affects microRNA target genes and cell viability of melanoma cells - Linck-Paulus, Lisa; Horn, Angelika; Matthies, Alexander Oliver; Fischer, S.; Meister, G.; Sticht, Heinrich; Kappelmann-Fenzl, M.; Boßerhoff, Anja Katrin (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2022)
CRIS-Team WoS Importer:2022-09-23

A novel strain-specific neutralizing epitope on glycoprotein H of human cytomegalovirus - Thomas, Marco; Kropff, Barbara; Schneider, Andrea; Winkler, Thomas; Görzer, Irene; Sticht, Heinrich; Britt, William J.; Mach, Michael; Reuter, Nina (Journal of Virology, 2021)
Human cytomegalovirus (HCMV) is a ubiquitous pathogen that causes severe clinical disease in immunosuppressed patients and congenitally infected newborn infants. Viral envelope glycoproteins represent attractive targets for vaccination or passive immunotherapy. To extend the knowledge of mechanisms of virus neutralization, monoclonal antibodies (MAbs) were generated following immunization of mice with HCMV virions. Hybridoma supernatants were screened for in vitro neutralization activity, yielding three potent MAbs, 6E3, 3C11, and 2B10. MAbs 6E3 and 3C11 blocked infection of all viral strains that were tested, while MAb 2B10 neutralized only 50% of the HCMV strains analyzed. Characterization of the MAbs using indirect immunofluorescence analyses demonstrated their reactivity with recombinantly derived gH. While MAbs 6E3 and 3C11 reacted with gH when expressed alone, 2B10 detected gH only when it was coexpressed with gB and gL. Recognition of gH by 3C11 was dependent on the expression of the entire ectodomain of gH, whereas 6E3 required residues 1 to 629 of gH. The strain-specific determinant for neutralization by Mab 2B10 was identified as a single Met!Ile amino acid polymorphism within gH, located within the central part of the protein. The polymorphism is evenly distributed among described HCMV strains. The 2B10 epitope thus represents a novel strain-specific antibody target site on gH of HCMV. The dependence of the reactivity of 2B10 on the simultaneous presence of gB/gH/gL will be of value in the structural definition of this tripartite complex. The 2B10 epitope may also represent a valuable tool for diagnostics to monitor infections/reinfections with different HCMV strains during pregnancy or after transplantation. IMPORTANCE HCMV infections are life threatening to people with compromised or immature immune systems. Understanding the antiviral antibody repertoire induced during HCMV infection is a necessary prerequisite to define protective antibody responses. Here, we report three novel anti-gH MAbs that potently neutralized HCMV infectivity. One of these MAbs (2B10) targets a novel strain-specific conformational epitope on gH that only becomes accessible upon coexpression of the minimal fusion machinery gB/gH/gL. Strain specificity is dependent on a single amino acid polymorphism within gH. Our data highlight the importance of strain-specific neutralizing antibody responses against HCMV. The 2B10 epitope may also represent a valuable tool for diagnostics to monitor infections/reinfections with different HCMV strains during pregnancy or after transplantation. In addition, the dependence of the reactivity of 2B10 on the simultaneous presence of gB/gH/gL will be of value in the structural definition of this tripartite complex.
CRIS-Team Scopus Importer:2021-09-10
Keywords: Glycoprotein H; Herpesviruses; Human cytomegalovirus; Neutralizing antibodies

Antagonistic cross-regulation between Sox9 and Sox10 controls an anti-tumorigenic program in melanoma - Shakhova, Olga; Cheng, Phil; Mishra, Pravin J.; Zingg, Daniel; Schaefer, Simon M.; Debbache, Julien; Haeusel, Jessica; Matter, Claudia; Guo, Theresa; Davis, Sean; Meltzer, Paul; Mihic-Probst, Daniela; et al. (PLoS Genetics, 2015)
Melanoma is the most fatal skin cancer, but the etiology of this devastating disease is still poorly understood. Recently, the transcription factor Sox10 has been shown to promote both melanoma initiation and progression. Reducing SOX10 expression levels in human melanoma cells and in a genetic melanoma mouse model, efficiently abolishes tumorigenesis by inducing cell cycle exit and apoptosis. Here, we show that this anti-tumorigenic effect functionally involves SOX9, a factor related to SOX10 and upregulated in melanoma cells upon loss of SOX10. Unlike SOX10, SOX9 is not required for normal melanocyte stem cell function, the formation of hyperplastic lesions, and melanoma initiation. To the contrary, SOX9 overexpression results in cell cycle arrest, apoptosis, and a gene expression profile shared by melanoma cells with reduced SOX10 expression. Moreover, SOX9 binds to the SOX10 promoter and induces downregulation of SOX10 expression, revealing a feedback loop reinforcing the SOX10 low/SOX9 high ant,m/ii-tumorigenic program. Finally, SOX9 is required in vitro and in vivo for the anti-tumorigenic effect achieved by reducing SOX10 expression. Thus, SOX10 and SOX9 are functionally antagonistic regulators of melanoma development.
EVALuna2:4983

Anterior segment dysgenesis in the eyes of mice deficient for the high-mobility-group transcription factor Sox11. - Sock, Elisabeth; Wegner, Michael; et al. (Experimental Eye Research, 2008)
We describe that Sox11, a member of the group C of the Sox transcription factor family, is critically required during the morphogenetic processes of early eye development, and that lack of Sox11 results in ocular anterior segment dysgenesis (ASD). Sox11-deficient mice show a persistent lens stalk, a delay in lens formation, and the phenotypes of Peters' anomaly and microphthalmia at birth. In addition, the optic fissure does not close in the anterior halves of the eyes resulting in anterior coloboma. The delay in lens formation is associated with a reduced mitotic activity in the lens placode during its invagination into the optic cup. No changes in Pax6 expression are observed in the developing eyes of Sox11-/- mice, whereas the expression of Sox11 is reduced in optic cup, optic vesicle and lens placode of Pax6+/- embryos and in the optic vesicle of Pax6-/- mice. Transfection experiments show an increase in Sox11 expression when higher doses of Pax6 are present. Considerably smaller amounts of BMP7 are expressed in lens and optic cup of Sox11-/- mice as compared to their wild-type littermates. We conclude that Sox11 is required during separation of the lens vesicle from the surface ectoderm and the closure of the anterior optic fissure. The expression of Sox11 in early eye development is under control of Pax6, and changes in BMP7-signalling appear to be involved in the effects of Sox11 on anterior eye development. Our findings suggest that SOX11 might similarly be involved in the pathogenesis of ASD in human patients. © 2008 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2008.med.IB.LPCIPDBI.anteri
Keywords: BMP7; coloboma; Pax6; Peters' anomaly

Antisense inhibition of enolase strongly limits the metabolism of aromatic amino acids, but has only minor effects on respiration in leaves of transgenic tobacco plants - Voll, Lars M.; Hajirezaei, Mohammad R.; Czogalla-Peter, Caecilia; Lein, Wolfgang; Stitt, Mark; Sonnewald, Uwe; Boernke, Frederik (New Phytologist, 2009)
We conclude that a decrease in enolase activity affects secondary pathways, such as the shikimate branch of amino acid biosynthesis, but does not inhibit the rate of respiration.
Keywords: amino acids; antisense; enolase; glycolysis; phosphoenolpyruvate

A pair of non‐competing neutralizing human monoclonal antibodies protecting from disease in a SARS‐CoV‐2 infection model - Peter, Antonia Sophia; Roth, Edith; Schulz, Sebastian; Fraedrich, Kirsten; Steinmetz, Tobit; Damm, Dominik; Hauke, Manuela; Richel, Elie; Müller-Schmucker, Sandra; Habenicht, Katharina Marie; Eberlein, Valentina; Issmail, Leila; et al. (European Journal of Immunology, 2021)
TRIANNI mice carry an entire set of human immunoglobulin V region gene segments and are a powerful tool to rapidly isolate human monoclonal antibodies. After immunizing these mice with DNA encoding the spike protein of SARS-CoV-2 and boosting with spike protein, we identified 29 hybridoma antibodies that reacted with the SARS-CoV-2 spike protein. Nine antibodies neutralize SARS-CoV-2 infection at IC50 values in the subnanomolar range. ELISA-binding studies and DNA sequence analyses revealed one cluster of three clonally related neutralizing antibodies that target the receptor-binding domain and compete with the cellular receptor hACE2. A second cluster of six clonally related neutralizing antibodies bind to the N-terminal domain of the spike protein without competing with the binding of hACE2 or cluster 1 antibodies. SARS-CoV-2 mutants selected for resistance to an antibody from one cluster are still neutralized by an antibody from the other cluster. Antibodies from both clusters markedly reduced viral spread in mice transgenic for human ACE2 and protected the animals from SARS-CoV-2-induced weight loss. The two clusters of potent non-competing SARS-CoV-2 neutralizing antibodies provide potential candidates for therapy and prophylaxis of COVID-19. The study further supports transgenic animals with a human immunoglobulin gene repertoire as a powerful platform in pandemic preparedness initiatives.

A Peroxisomal Disorder of Severe Intellectual Disability, Epilepsy, and Cataracts Due to Fatty Acyl-CoA Reductase 1 Deficiency - Buchert, Rebecca; Tawamie, Hasan; Smith, Christopher; Uebe, Steffen; Innes, A. Micheil; Al Hallak, Bassam; Ekici, Arif Bülent; Sticht, Heinrich; Schwarze, Bernd; Lamont, Ryan E.; Parboosingh, Jillian S.; Bernier, Francois P.; et al. (American Journal of Human Genetics, 2014)
Rhizomelic chondrodysplasia punctata (RCDP) is a group of disorders with overlapping clinical features including rhizomelia, chondrodysplasia punctata, coronal clefts, cervical dysplasia, congenital cataracts, profound postnatal growth retardation, severe intellectual disability, and seizures. Mutations in PEX7, GNPAT, and AGPS, all involved in the plasmalogen-biosynthesis pathway, have been described in individuals with RCDP. Here, we report the identification of mutations in another gene in plasmalogen biosynthesis, fatty acyl-CoA reductase 1 (FAR1), in two families affected by severe intellectual disability, early-onset epilepsy, microcephaly, congenital cataracts, growth retardation, and spasticity. Exome analyses revealed a homozygous in-frame indel mutation (c.495_507delinsT [p.Glu165_Pro169delinsAsp]) in two siblings from a consanguineous family and compound-heterozygous mutations (c.[787C>T];[1094A>G], p.[Arg263(*)];[Asp365Gly]) in a third unrelated individual. FAR1 reduces fatty acids to their respective fatty alcohols for the plasmalogen-biosynthesis pathway. To assess the pathogenicity of the identified mutations, we transfected human embryonic kidney 293 cells with plasmids encoding FAR1 with either wild-type or mutated constructs and extracted the lipids from the cells. We screened the lipids with gas chromatography and mass spectrometry and found that all three mutations abolished the reductase activity of FAR1, given that no fatty alcohols could be detected. We also observed reduced plasmalogens in red blood cells in one individual to a range similar to that seen in individuals with RCDP, further supporting abolished FAR1 activity. We thus expand the spectrum of clinical features associated with defects in plasmalogen biosynthesis to include FAR1 deficiency as a cause of syndromic severe intellectual disability with cataracts, epilepsy, and growth retardation but without rhizomelia.
EVALuna2:9238

Application of information theory to feature selection in protein docking - Othersen, Olaf; Stefani, Arno; Huber, Johannes; Sticht, Heinrich (Journal of Molecular Modeling, 2012)
In the era of structural genomics, the prediction of protein interactions using docking algorithms is an important goal. The success of this method critically relies on the identification of good docking solutions among a vast excess of false solutions. We have adapted the concept of mutual information (MI) from information theory to achieve a fast and quantitative screening of different structural features with respect to their ability to discriminate between physiological and nonphysiological protein interfaces. The strategy includes the discretization of each structural feature into distinct value ranges to optimize its mutual information. We have selected 11 structural features and two datasets to demonstrate that the MI is dimensionless and can be directly compared for diverse structural features and between datasets of different sizes. Conversion of the MI values into a simple scoring function revealed that those features with a higher MI are actually more powerful for the identification of good docking solutions. Thus, an MI-based approach allows the rapid screening of structural features with respect to their information content and should therefore be helpful for the design of improved scoring functions in future. In addition, the concept presented here may also be adapted to related areas that require feature selection for biomolecules or organic ligands.
EVALuna2:26271

A previously unknown Argonaute 2 variant positively modulates the viability of melanoma cells - Linck-Paulus, Lisa; Meißgeier, Tina; Pieger, Katharina; Horn, Anselm; Matthies, Alexander Oliver; Fischer, Stefan; Meister, Gunter; Sticht, Heinrich; Kappelmann-Fenzl, Melanie; Boßerhoff, Anja Katrin (Cellular and Molecular Life Sciences, 2022)
In malignant melanoma, a highly aggressive form of skin cancer, many microRNAs are aberrantly expressed contributing to tumorigenesis and progression. Further, deregulation of microRNA processing enzymes, like the miRNA-binding protein Argonaute 2, significantly impacts microRNA function. This study characterizes a novel splice variant of Argonaut 2, AGO2-ex1/3. AGO2-ex1/3 is substantially expressed in different melanoma cell lines and patient-derived tissue samples. It is a mature mRNA, which is translated into an N-terminally truncated Argonaute 2 protein form. Molecular dynamics simulations show that the PAZ, MID, and PIWI domain largely retain their structure in AGO2-ex1/3 and that the truncation of the N-terminus leads to an increased interdomain flexibility. Expression of AGO2-ex1/3 provides a survival advantage for melanoma cells while the knockdown causes significantly reduced proliferation and increases apoptosis. RNA-sequencing revealed that in cells lacking AGO2-ex1/3 expression many miRNA target genes are deregulated, implicating a considerable role of AGO2-ex1/3 for miRNA function. This study inaugurates insights into an important role of a so far unknown splice variant of Argonaute 2 for the miRNA pathway as well as the mechanisms which drive growth and survival of melanoma cells. This knowledge provides the basis for potential new promising therapeutic targets focusing on small RNA-mediated gene regulation in melanoma.
CRIS-Team Scopus Importer:2022-08-19
Keywords: Alternative splicing; Argonaute 2; Melanoma; miRNAs

A proline-rich motif in the large intracellular loop of the glycine receptor α1 subunit interacts with the Pleckstrin homology domain of collybistin - Breitinger, Ulrike; Weinländer, Kristina; Pechmann, Yvonne; Langlhofer, Georg; Enz, Ralf; Becker, Cord-Michael; Sticht, Heinrich; Kneussel, Matthias; Villmann, Carmen; Breitinger, Hans Georg (Journal of Advanced Research, 2020)
Introduction: The inhibitory glycine receptor (GlyR), a mediator of fast synaptic inhibition, is located and held at neuronal synapses through the anchoring proteins gephyrin and collybistin. Stable localization of neurotransmitter receptors is essential for synaptic function. In case of GlyRs, only beta subunits were known until now to mediate synaptic anchoring. Objectives: We identified a poly-proline II helix (PPII) in position 365–373 of the intra-cellular TM3-4 loop of the human GlyRα1 subunit as a novel potential synaptic anchoring site. The potential role of the PPII helix as synaptic anchoring site was tested. Methods: Glycine receptors and collybistin variants were generated and recombinantly expressed in HEK293 cells and cultured neurons. Receptor function was assessed using patch-clamp electrophysiology, protein-protein interaction was studied using co-immuno-precipitation and pulldown experiments. Results: Recombinantly expressed collybistin bound to isolated GlyRα1 TM3-4 loops in GST-pulldown assays. When the five proline residues P365A, P366A, P367A, P369A, P373A (GlyRα1P1-5A) located in the GlyRα1-PPII helix were replaced by alanines, the PPII secondary structure was disrupted. Recombinant GlyRα1P1-5A mutant subunits displayed normal cell surface expression and wildtype-like ion channel function, but binding to collybistin was abolished. The GlyRα1-collybistin interaction was independently confirmed by o-immunoprecipitation assays using full-length GlyRα1 subunits. Surprisingly, the interaction was not mediated by the SH3 domain of collybistin, but by its Pleckstrin homology (PH) domain. The mutation GlyRα1P366L, identified in a hyperekplexia patient, is also disrupting the PPII helix, and caused reduced collybistin binding. Conclusion: Our data suggest a novel interaction between α1 GlyR subunits and collybistin, which is physiologically relevant in vitro and in vivo and may contribute to postsynaptic anchoring of glycine receptors.
CRIS-Team Scopus Importer:2020-10-30
Keywords: Collybistin; Gephyrin; Glycine receptor alpha1 subunit; Ion channel receptors; Pleckstrin homology domains; Polyproline II helix; Protein-protein interaction; SH3 domains; Synaptic anchoring

A retroelement modifies pre-mRNA splicing: The murine Glrbspa allele is a splicing signal polymorphism amplified by long interspersed nuclear element insertion - Becker, Kristina; Braune, Marlen; Benderska, Natalya; Buratti, Emanuele; Baralle, Francisco; Villmann, Carmen; Stamm, Stefan; Eulenburg, Volker; Becker, Cord-Michael (Journal of Biological Chemistry, 2012)
The glycine receptor-deficient mutant mouse spastic carries a full-length long interspersed nuclear element (LINE1) retrotransposon in intron 6 of the glycine receptor β subunit gene, Glrb(spa). The mutation arose in the C57BL/6J strain and is associated with skipping of exon 6 or a combination of the exons 5 and 6, thus resulting in a translational frameshift within the coding regions of the GlyR β subunit. The effect of the Glrb(spa) LINE1 insertion on pre-mRNA splicing was studied using a minigene approach. Sequence comparison as well as motif prediction and mutational analysis revealed that in addition to the LINE1 insertion the inactivation of an exonic splicing enhancer (ESE) within exon 6 is required for skipping of exon 6. Reconstitution of the ESE by substitution of a single residue was sufficient to prevent exon skipping. In addition to the ESE, two regions within the 5' and 3' UTR of the LINE1 were shown to be critical determinants for exon skipping, indicating that LINE1 acts as efficient modifier of subtle endogenous splicing phenotypes. Thus, the spastic allele of the murine glycine receptor β subunit gene is a two-hit mutation, where the hypomorphic alteration in an ESE is amplified by the insertion of a LINE1 element in the adjacent intron. Conversely, the LINE1 effect on splicing may be modulated by individual polymorphisms, depending on the insertional environment within the host genome.

Argonaute Family Protein Expression in Normal Tissue and Cancer Entities - Voeller, Daniel; Linck, Lisa; Bruckmann, Astrid; Hauptmann, Judith; Deutzmann, Rainer; Meister, Gunter; Boßerhoff, Anja Katrin (PLoS ONE, 2016)
The members of the Argonaute (AGO) protein family are key players in miRNA-guided gene silencing. They enable the interaction between small RNAs and their respective target mRNA(s) and support the catalytic destruction of the gene transcript or recruit additional proteins for downstream gene silencing. The human AGO family consists of four AGO proteins (AGO1-AGO4), but only AGO2 harbors nuclease activity. In this study, we characterized the expression of the four AGO proteins in cancer cell lines and normal tissues with a new mass spectrometry approach called AGO-APP (AGO Affinity Purification by Peptides). In all analyzed normal tissues, AGO1 and AGO2 were most prominent, but marked tissue-specific differences were identified. Furthermore, considerable changes during development were observed by comparing fetal and adult tissues. We also identified decreased overall AGO expression in melanoma derived cell lines compared to other tumor cell lines and normal tissues, with the largest differences in AGO2 expression. The experiments described in this study suggest that reduced amounts of AGO proteins, as key players in miRNA processing, have impact on several cellular processes. Deregulated miRNA expression has been attributed to chromosomal aberrations, promoter regulation and it is known to have a major impact on tumor development and progression. Our findings will further increase our basic understanding of the molecular basis of miRNA processing and its relevance for disease.
EVALuna2:4734

A severe congenital myasthenic syndrome with "dropped head" caused by novel MUSK mutations - Giarrana, Miriam L.; Joset, Pascal; Sticht, Heinrich; Robb, Stephanie; Steindl, Katharina; Rauch, Anita; Klein, Andrea (Muscle & Nerve, 2015)
Congenital myasthenic syndromes are rare. Mutations in MUSK were first described in 2004. Thirteen patients have been reported to date, mostly with a relatively mild course. The molecular diagnosis has implications for choice of treatment and genetic counseling.Clinical course and electrophysiological, pathological, and genetic findings were assessed.We describe the case of a boy with prenatal onset and severe respiratory symptoms with a persisting need for ventilation. The patient had severe bulbar symptoms, marked axial weakness causing a "dropped head," and some facial and proximal weakness. Ophthalmoparesis developed during the first year of life. Salbutamol led to improvement, 3,4-diaminopyridine had a modest effect, but pyridostigmine produced deterioration. Two novel mutations in MUSK were found by whole exome sequencing.We expand the phenotype of congenital myasthenic syndromes with MUSK mutations, describing a more severe clinical course with prenatal onset. Predominant bulbar and respiratory weakness with facial and axial weakness and ophthalmoparesis are diagnostic clues.
EVALuna2:26289

A shared transcriptional code orchestrates temporal patterning of the central nervous system - Sagner, Andreas; Zhang, Isabel; Watson, Thomas; Lazaro, Jorge; Melchionda, Manuela; Briscoe, James (Plos Biology, 2021)
The molecular mechanisms that produce the full array of neuronal subtypes in the vertebrate nervous system are incompletely understood. Here, we provide evidence of a global temporal patterning program comprising sets of transcription factors that stratifies neurons based on the developmental time at which they are generated. This transcriptional code acts throughout the central nervous system, in parallel to spatial patterning, thereby increasing the diversity of neurons generated along the neuraxis. We further demonstrate that this temporal program operates in stem cell-derived neurons and is under the control of the TGFβ signaling pathway. Targeted perturbation of components of the temporal program, Nfia and Nfib, reveals their functional requirement for the generation of late-born neuronal subtypes. Together, our results provide evidence for the existence of a previously unappreciated global temporal transcriptional program of neuronal subtype identity and suggest that the integration of spatial and temporal patterning mechanisms diversifies and organizes neuronal subtypes in the vertebrate nervous system. Copyright:
CRIS-Team Scopus Importer:2021-12-10

A single-nucleotide polymorphism in Helicobacter pylori promotes gastric cancer development - Sharafutdinov, Irshad; Tegtmeyer-Backert, Nicole; Linz, Bodo; Rohde, Manfred; Vieth, Michael; Tay, Alfred Chin Yen; Lamichhane, Binit; Tuan, Vo Phuoc; Fauzia, Kartika Afrida; Sticht, Heinrich; Yamaoka, Yoshio; Marshall, Barry J.; et al. (Cell Host & Microbe, 2023)
Single-nucleotide polymorphisms (SNPs) in various human genes are key factors in carcinogenesis. However, whether SNPs in bacterial pathogens are similarly crucial in cancer development is unknown. Here, we analyzed 1,043 genomes of the stomach pathogen Helicobacter pylori and pinpointed a SNP in the serine protease HtrA (position serine/leucine 171) that significantly correlates with gastric cancer. Our functional studies reveal that the 171S-to-171L mutation triggers HtrA trimer formation and enhances proteolytic activity and cleavage of epithelial junction proteins occludin and tumor-suppressor E-cadherin. 171L-type HtrA, but not 171S-HtrA-possessing H. pylori, inflicts severe epithelial damage, enhances injection of oncoprotein CagA into epithelial cells, increases NF-κB-mediated inflammation and cell proliferation through nuclear accumulation of β-catenin, and promotes host DNA double-strand breaks, collectively triggering malignant changes. These findings highlight the 171S/L HtrA mutation as a unique bacterial cancer-associated SNP and as a potential biomarker for risk predictions in H. pylori infections.
CRIS-Team Scopus Importer:2023-08-25
Keywords: 53BP1; DNA double-strand breaks; gastric cancer; H. pylori; HtrA; NF-κB; PFGE; signaling; SNP; β-catenin

A single point mutation decreases picrotoxinin sensitivity of the human GABA receptor *1 subunit. - Enz, Ralf (NeuroReport, 1995)
UnivIS-Import:2017-12-18:Pub.1995.med.IB.profes_1.asingl

A Sox10 rtTA mouse line for tetracycline-inducible expression of transgenes in neural crest cells and oligodendrocytes. - Wegner, Michael; et al. (Genesis, 2004)
UnivIS-Import:2015-03-09:Pub.2004.med.IB.LPCIPDBI.asox10

A specific A/T polymorphism in Western tyrosine phosphorylation B-motifs regulates Helicobacter pylori CagA epithelial cell interactions - Zhang, Xue-Song; Tegtmeyer, Nicole; Traube, Leah; Jindal, Shawn; Perez-Perez, Guillermo; Sticht, Heinrich; Backert, Steffen; Blaser, Martin J. (PLoS Pathogens, 2015)
Helicobacter pylori persistently colonizes the human stomach, with mixed roles in human health. The CagA protein, a key host-interaction factor, is translocated by a type IV secretion system into host epithelial cells, where its EPIYA tyrosine phosphorylation motifs (TPMs) are recognized by host cell kinases, leading to multiple host cell signaling cascades. The CagA TPMs have been described as type A, B, C or D, each with a specific conserved amino acid sequence surrounding EPIYA. Database searching revealed strong non-random distribution of the B-motifs (including EPIYA and EPIYT) in Western H. pylori isolates. In silico analysis of Western H. pylori CagA sequences provided evidence that the EPIYT B-TPMs are significantly less associated with gastric cancer than the EPIYA B-TPMs. By generating and using a phosphorylated CagA B-TPM-specific antibody, we demonstrated the phosphorylated state of the CagA B-TPM EPIYT during H. pylori co-culture with host cells. We also showed that within host cells, CagA interaction with phosphoinositol 3-kinase (PI3-kinase) was B-TPM tyrosine-phosphorylation-dependent, and the recombinant CagA with EPIYT B-TPM had higher affinity to PI3-kinase and enhanced induction of AKT than the isogenic CagA with EPIYA B-TPM. Structural modeling of the CagA B-TPM motif bound to PI3-kinase indicated that the threonine residue at the pY+1 position forms a side-chain hydrogen bond to N-417 of PI3-kinase, which cannot be formed by alanine. During co-culture with AGS cells, an H. pylori strain with a CagA EPIYT B-TPM had significantly attenuated induction of interleukin-8 and hummingbird phenotype, compared to the isogenic strain with B-TPM EPIYA. These results suggest that the A/T polymorphisms could regulate CagA activity through interfering with host signaling pathways related to carcinogenesis, thus influencing cancer risk.
EVALuna2:26288

Assessing clinical utility of preconception expanded carrier screening regarding residual risk for neurodevelopmental disorders - Boonsawat, Paranchai; Horn, Anselm H. C.; Steindl, Katharina; Baumer, Alessandra; Joset, Pascal; Kraemer, Dennis; Bahr, Angela; Ivanovski, Ivan; Cabello, Elena M.; Papik, Michael; Zweier, Markus; Oneda, Beatrice; et al. (npj Genomic Medicine, 2022)
The magnitude of clinical utility of preconception expanded carrier screening (ECS) concerning its potential to reduce the risk of affected offspring is unknown. Since neurodevelopmental disorders (NDDs) in their offspring is a major concern of parents-to-be, we addressed the question of residual risk by assessing the risk-reduction potential for NDDs in a retrospective study investigating ECS with different criteria for gene selection and definition of pathogenicity. We used exome sequencing data from 700 parents of children with NDDs and blindly screened for carrier-alleles in up to 3046 recessive/X-linked genes. Depending on variant pathogenicity thresholds and gene content, NDD-risk-reduction potential was up to 43.5% in consanguineous, and 5.1% in nonconsanguineous couples. The risk-reduction-potential was compromised by underestimation of pathogenicity of missense variants (false-negative-rate 4.6%), inherited copy-number variants and compound heterozygosity of one inherited and one de novo variant (0.9% each). Adherence to the ACMG recommendations of restricting ECS to high-frequency genes in nonconsanguineous couples would more than halve the detectable inherited NDD-risk. Thus, for optimized clinical utility of ECS, screening in recessive/X-linked genes regardless of their frequency (ACMG Tier-4) and sensible pathogenicity thresholds should be considered for all couples seeking ECS.
CRIS-Team Scopus Importer:2022-08-12

Assessment of Covalently Binding Warhead Compounds in the Validation of the Cytomegalovirus Nuclear Egress Complex as an Antiviral Target - Tillmanns, Julia; Häge, Sigrun; Borst, Eva Maria; Wardin, Julia; Eickhoff, Jan; Klebl, Bert; Wagner, Sabrina; Wangen, Christina; Hahn, Friedrich; Socher, Eileen; Marschall, Manfred (Cells, 2023)
Herpesviral nuclear egress is a regulated process of viral capsid nucleocytoplasmic release. Due to the large capsid size, a regular transport via the nuclear pores is unfeasible, so that a multistage-regulated export pathway through the nuclear lamina and both leaflets of the nuclear membrane has evolved. This process involves regulatory proteins, which support the local distortion of the nuclear envelope. For human cytomegalovirus (HCMV), the nuclear egress complex (NEC) is determined by the pUL50–pUL53 core that initiates multicomponent assembly with NEC-associated proteins and capsids. The transmembrane NEC protein pUL50 serves as a multi-interacting determinant that recruits regulatory proteins by direct and indirect contacts. The nucleoplasmic core NEC component pUL53 is strictly associated with pUL50 in a structurally defined hook-into-groove complex and is considered as the potential capsid-binding factor. Recently, we validated the concept of blocking the pUL50–pUL53 interaction by small molecules as well as cell-penetrating peptides or an overexpression of hook-like constructs, which can lead to a pronounced degree of antiviral activity. In this study, we extended this strategy by utilizing covalently binding warhead compounds, originally designed as binders of distinct cysteine residues in target proteins, such as regulatory kinases. Here, we addressed the possibility that warheads may likewise target viral NEC proteins, building on our previous crystallization-based structural analyses that revealed distinct cysteine residues in positions exposed from the hook-into-groove binding surface. To this end, the antiviral and NEC-binding properties of a selection of 21 warhead compounds were investigated. The combined findings are as follows: (i) warhead compounds exhibited a pronounced anti-HCMV potential in cell-culture-based infection models; (ii) computational analysis of NEC primary sequences and 3D structures revealed cysteine residues exposed to the hook-into-groove interaction surface; (iii) several of the active hit compounds exhibited NEC-blocking activity, as shown at the single-cell level by confocal imaging; (iv) the clinically approved warhead drug ibrutinib exerted a strong inhibitory impact on the pUL50–pUL53 core NEC interaction, as demonstrated by the NanoBiT assay system; and (v) the generation of recombinant HCMV ∆UL50-ΣUL53, allowing the assessment of viral replication under conditional expression of the viral core NEC proteins, was used for characterizing viral replication and a mechanistic evaluation of ibrutinib antiviral efficacy. Combined, the results point to a rate-limiting importance of the HCMV core NEC for viral replication and to the option of exploiting this determinant by the targeting of covalently NEC-binding warhead compounds.
Created from Fastlane, Scopus look-up
Keywords: antiviral targeting based on NEC 3D structures; conditional expression of viral core NEC proteins; covalently binding warhead compounds; human cytomegalovirus; nuclear egress complex (NEC); pronounced NEC-directed antiviral activity; regulation of viral replication

Assessment of heat treatment of dairy products by MALDI-TOF-MS - Meltretter, Jasmin; Birlouez-Aragon, Inés; Becker, Cord-Michael; Pischetsrieder, Monika (Molecular Nutrition & Food Research, 2009)
The formation of the Amadori product from lactose (protein lactosylation) is a major parameter to evaluate the quality of processed milk. Here, MALDI-TOF-MS was used for the relative quantification of lactose-adducts in heated milk. Milk was heated at a temperature of 70, 80, and 1001C between 0 and 300min, diluted, and subjected directly to MALDI-TOF-MS. The lactosylation rate of a-lactalbumin increased with increasing reaction temperature and time. The results correlated well with established markers for heat treatment of milk (concentration of total soluble protein, soluble a-lactalbumin and b-lactoglobulin at pH 4.6, and fluorescence of advanced Maillard products and soluble tryptophan index; r = 0.969-0.997). The method was also applied to examine commercially available dairy products. In severely heated products, protein pre-purification by immobilized metal affinity chromatography improved spectra quality. Relative quantification of protein lactosylation by MALDI-TOF-MS proved to be a very fast and reliable method to monitor early Maillard reaction during milk processing. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
UnivIS-Import:2015-03-09:Pub.2009.nat.dchph.llmch.assess
Keywords: Amadori product; Maillard reaction; MALDI-TOF-MS; Milk; Relative quantification

Association of polymorphous light eruption with NOD-2 and TLR-5 gene polymorphisms - Kurz, B.; Arndt, S.; Unger, P.; Ivanova, I.; Berneburg, M.; Hellerbrand, Claus; Karrer, S. (Journal of the European Academy of Dermatology and Venereology, 2022)
Background: Polymorphous light eruption (PLE) is a common, immunologically mediated, photosensitive skin disease. After ultraviolet-B (UV-B) irradiation, patients with PLE show reduced Langerhans cell (LC) depletion in the epidermis, which results in a non-suppressive microenvironment in the skin. Interestingly, severe acute graft-versus-host disease (aGvHD) occurred in stem cell transplanted patients that showed no or incomplete depletion of LCs after UVB irradiation. Genetic variation in nucleotide-binding oligomerization domain 2 (NOD-2) and toll-like receptor 5 (TLR-5) genes also confers susceptibility to aGvHD. Objectives: We hypothesized that PLE is associated with genetic variation in the NOD-2 and TLR-5 genes. Methods: We investigated single-nucleotid polymorphisms (SNPs) of NOD-2 (R702W, G908R, 3020Cins) and TLR-5 (A592S, P616L, N392STOP) in skin biopsies of patients with PLE (n = 143) and in healthy controls (n = 104) using restriction fragment length polymorphism analysis. Results: The frequency of NOD-2 alleles with the SNP R702W was significantly higher in PLE than in controls (31.8% vs. 6.3%; P < 0.0001), and homozygous carriers of this mutation were more common in PLE (27.9% vs. 0%; P < 0.0001). For SNP 3020Cins, the allele frequency (7.3% vs. 0.7%; P = 0.0025) and the number of heterozygotes (14.7% vs. 1.3%; P = 0.0019) were higher in PLE. The frequency of alleles with the N392STOP SNP of the TLR5 gene, which is associated with a truncated, non-functional receptor, was significantly higher in PLE (21% vs. 5%; 7% vs. 1% homozygotes, 28% vs. 8% heterozygotes; P < 0.0001). The other SNPs did not differ significantly. Conclusions: This study yielded a high frequency of functional SNPs in the NOD-2 and TLR-5 genes in PLE. The same SNPs are associated with aGvHD and there are similarities in the reaction of LCs after UVB irradiation between aGvHD and PLE. This leads to the hypothesis that patients with PLE may be more susceptible to developing GvHD after stem cell transplantation, an assumption that needs to be investigated further.
CRIS-Team Scopus Importer:2022-07-15

Association of Rare CYP39A1 Variants with Exfoliation Syndrome Involving the Anterior Chamber of the Eye - Li, Zheng; Wang, Zhenxun; Lee, Mei Chin; Zenkel, Matthias; Peh, Esther; Ozaki, Mineo; Topouzis, Fotis; Nakano, Satoko; Chan, Anita; Chen, Shuwen; Williams, Susan E.I.; Orr, Andrew; et al. (Journal of the American Medical Association, 2021)
Importance: Exfoliation syndrome is a systemic disorder characterized by progressive accumulation of abnormal fibrillar protein aggregates manifesting clinically in the anterior chamber of the eye. This disorder is the most commonly known cause of glaucoma and a major cause of irreversible blindness. Objective: To determine if exfoliation syndrome is associated with rare, protein-changing variants predicted to impair protein function. Design, Setting, and Participants: A 2-stage, case-control, whole-exome sequencing association study with a discovery cohort and 2 independently ascertained validation cohorts. Study participants from 14 countries were enrolled between February 1999 and December 2019. The date of last clinical follow-up was December 2019. Affected individuals had exfoliation material on anterior segment structures of at least 1 eye as visualized by slit lamp examination. Unaffected individuals had no signs of exfoliation syndrome. Exposures: Rare, coding-sequence genetic variants predicted to be damaging by bioinformatic algorithms trained to recognize alterations that impair protein function. Main Outcomes and Measures: The primary outcome was the presence of exfoliation syndrome. Exome-wide significance for detected variants was defined as P < 2.5 × 10-6. The secondary outcomes included biochemical enzymatic assays and gene expression analyses. Results: The discovery cohort included 4028 participants with exfoliation syndrome (median age, 78 years [interquartile range, 73-83 years]; 2377 [59.0%] women) and 5638 participants without exfoliation syndrome (median age, 72 years [interquartile range, 65-78 years]; 3159 [56.0%] women). In the discovery cohort, persons with exfoliation syndrome, compared with those without exfoliation syndrome, were significantly more likely to carry damaging CYP39A1 variants (1.3% vs 0.30%, respectively; odds ratio, 3.55 [95% CI, 2.07-6.10]; P = 6.1 × 10-7). This outcome was validated in 2 independent cohorts. The first validation cohort included 2337 individuals with exfoliation syndrome (median age, 74 years; 1132 women; n = 1934 with demographic data) and 2813 individuals without exfoliation syndrome (median age, 72 years; 1287 women; n = 2421 with demographic data). The second validation cohort included 1663 individuals with exfoliation syndrome (median age, 75 years; 587 women; n = 1064 with demographic data) and 3962 individuals without exfoliation syndrome (median age, 74 years; 951 women; n = 1555 with demographic data). Of the individuals from both validation cohorts, 5.2% with exfoliation syndrome carried CYP39A1 damaging alleles vs 3.1% without exfoliation syndrome (odds ratio, 1.82 [95% CI, 1.47-2.26]; P <.001). Biochemical assays classified 34 of 42 damaging CYP39A1 alleles as functionally deficient (median reduction in enzymatic activity compared with wild-type CYP39A1, 94.4% [interquartile range, 78.7%-98.2%] for the 34 deficient variants). CYP39A1 transcript expression was 47% lower (95% CI, 30%-64% lower; P <.001) in ciliary body tissues from individuals with exfoliation syndrome compared with individuals without exfoliation syndrome. Conclusions and Relevance: In this whole-exome sequencing case-control study, presence of exfoliation syndrome was significantly associated with carriage of functionally deficient CYP39A1 sequence variants. Further research is needed to understand the clinical implications of these findings.
CRIS-Team Scopus Importer:2021-03-05

Astrocytes and neurons share region-specific transcriptional signatures that confer regional identity to neuronal reprogramming - Herrero-Navarro, Alvaro; Puche-Aroca, Lorenzo; Moreno-Juan, Veronica; Sempere-Ferrandez, Alejandro; Espinosa, Ana; Susin, Rafael; Torres-Masjoan, Laia; Leyva-Diaz, Eduardo; Karow, Marisa; Figueres-Onate, Maria; Lopez-Mascaraque, Laura; Lopez-Atalaya, Jose P.; et al. (Science Advances, 2021)
Neural cell diversity is essential to endow distinct brain regions with specific functions. During development, progenitors within these regions are characterized by specific gene expression programs, contributing to the generation of diversity in postmitotic neurons and astrocytes. While the region-specific molecular diversity of neurons and astrocytes is increasingly understood, whether these cells share region-specific programs remains unknown. Here, we show that in the neocortex and thalamus, neurons and astrocytes express shared region-specific transcriptional and epigenetic signatures. These signatures not only distinguish cells across these two brain regions but are also detected across substructures within regions, such as distinct thalamic nuclei, where clonal analysis reveals the existence of common nucleus-specific progenitors for neurons and astrocytes. Consistent with their shared molecular signature, regional specificity is maintained following astrocyte-to-neuron reprogramming. A detailed understanding of these regional-specific signatures may thus inform strategies for future cell-based brain repair.
CRIS-Team Scopus Importer:2021-04-19

Astrocytes in the adult dentate gyrus—balance between adult and developmental tasks - Chalmers, Nicholas; Masouti, Evangelia; Beckervordersandforth, Ruth (Molecular Psychiatry, 2024)
Astrocytes, a major glial cell type in the brain, are indispensable for the integration, maintenance and survival of neurons during development and adulthood. Both life phases make specific demands on the molecular and physiological properties of astrocytes, and most research projects traditionally focus on either developmental or adult astrocyte functions. In most brain regions, the generation of brain cells and the establishment of neural circuits ends with postnatal development. However, few neurogenic niches exist in the adult brain in which new neurons and glial cells are produced lifelong, and the integration of new cells into functional circuits represent a very special form of plasticity. Consequently, in the neurogenic niche, the astrocytes must be equipped to execute both mature and developmental tasks in order to integrate newborn neurons into the circuit and yet maintain overall homeostasis without affecting the preexisting neurons. In this review, we focus on astrocytes of the hippocampal dentate gyrus (DG), and discuss specific features of the astrocytic compartment that may allow the execution of both tasks. Firstly, astrocytes of the adult DG are molecularly, morphologically and functionally diverse, and the distinct astrocytes subtypes are characterized by their localization to DG layers. This spatial separation may lead to a functional specification of astrocytes subtypes according to the neuronal structures they are embedded in, hence a division of labor. Secondly, the astrocytic compartment is not static, but steadily increasing in numbers due to lifelong astrogenesis. Interestingly, astrogenesis can adapt to environmental and behavioral stimuli, revealing an unexpected astrocyte dynamic that allows the niche to adopt to changing demands. The diversity and dynamic of astrocytes in the adult DG implicate a vital contribution to hippocampal plasticity and represent an interesting model to uncover mechanisms how astrocytes simultaneously fulfill developmental and adult tasks.
CRIS-Team Scopus Importer:2024-01-12

Astrogenesis and dynamic of astrocytes in the adult mouse hippocampus - Schneider, Julia; Karpf, J.; Beckervordersandforth, Ruth (GLIA, 2019)
CRIS-Team WoS Importer:2020-01-10

Astrogenesis in the murine dentate gyrus is a life-long and dynamic process - Schneider, Julia; Weigel, Johannes; Wittmann, Marie-Theres; Svehla, Pavel; Ehrt, Sebastian; Zheng, Fang; Elmzzahi, Tarek; Karpf, Julian; Paniagua-Herranz, Lucia; Basak, Onur; Ekici, Arif Bülent; Wiesmann da Silva Reis, André; et al. (EMBO Journal, 2022)
Astrocytes are highly abundant in the mammalian brain, and their functions are of vital importance for all aspects of development, adaption, and aging of the central nervous system (CNS). Mounting evidence indicates the important contributions of astrocytes to a wide range of neuropathies. Still, our understanding of astrocyte development significantly lags behind that of other CNS cells. We here combine immunohistochemical approaches with genetic fate-mapping, behavioral paradigms, single-cell transcriptomics, and in vivo two-photon imaging, to comprehensively assess the generation and the proliferation of astrocytes in the dentate gyrus (DG) across the life span of a mouse. Astrogenesis in the DG is initiated by radial glia-like neural stem cells giving rise to locally dividing astrocytes that enlarge the astrocyte compartment in an outside-in-pattern. Also in the adult DG, the vast majority of astrogenesis is mediated through the proliferation of local astrocytes. Interestingly, locally dividing astrocytes were able to adapt their proliferation to environmental and behavioral stimuli revealing an unexpected plasticity. Our study establishes astrocytes as enduring plastic elements in DG circuits, implicating a vital contribution of astrocyte dynamics to hippocampal plasticity.
CRIS-Team WoS Importer:2022-04-29

Astroglial changes induced by Gfap-dependent expression of a Sox9 transgene - Vogel, J. K.; Wegner, Michael (GLIA, 2021)
CRIS-Team WoS Importer:2021-07-16

A Survey of Biological Building Blocks for Synthetic Molecular Communication Systems - Söldner, Christian; Socher, Eileen; Jamali, Vahid; Wicke, Wayan; Ahmadzadeh, Arman; Breitinger, Hans Georg; Burkovski, Andreas; Castiglione, Kathrin; Schober, Robert; Sticht, Heinrich (IEEE Communications Surveys & Tutorials, 2020)
Synthetic molecular communication (MC) is a new communication engineering paradigm which is expected to enable revolutionary applications such as smart drug delivery and real-time health monitoring. The design and implementation of synthetic MC systems (MCSs) at nano- and microscale is very challenging. This is particularly true for synthetic MCSs employing biological components as transmitters and receivers or as interfaces with natural biological MCSs. Nevertheless, since such biological components have been optimized by nature over billions of years, using them in synthetic MCSs is highly promising. This paper provides a survey of biological components that can potentially serve as the main building blocks, i.e., transmitter, receiver, and signaling particles, for the design and implementation of synthetic MCSs. Nature uses a large variety of signaling particles of different sizes and with vastly different properties for communication among biological entities. Here, we focus on three important classes of signaling particles: cations (specifically protons and calcium ions), neurotransmitters (specifically acetylcholine, dopamine, and serotonin), and phosphopeptides. These three classes have unique and distinct features such as their large diffusion coefficients, their specificity, and/or their uniqueness of signaling that make them suitable candidates for signaling particles in synthetic MCSs. For each of these candidate signaling particles, we present several specific transmitter and receiver structures mainly built upon proteins that are capable of performing the distinct physiological functionalities required from the transmitters and receivers of MCSs. Moreover, we present options for both microscale implementation of MCSs as well as the micro-to-macroscale interfaces needed for experimental evaluation of MCSs. One of the main advantages of employing proteins for signal emission and detection is that they can be modified with tools from synthetic biology and be tailored to a wide range of application needs. We discuss the properties, limitations, and applications of the proposed biological building blocks for synthetic MCSs in detail. Furthermore, we outline new research directions for the implementation and the theoretical design and analysis of the proposed transmitter and receiver architectures.
CRIS-Team Scopus Importer:2020-12-04
Keywords: Molecular communications; signaling particles; synthetic biology; test-bed implementation; transmitter and receiver architecture

ATF2 loss promotes tumor invasion in colorectal cancer cells via upregulation of cancer driver TROP2 - Hübner, Kerstin; Erlenbach-Wünsch, Katharina; Prochazka, Jan; Sheraj, Ilir; Hampel, Chuanpit; Mrazkova, Blanka; Michalcikova, Tereza; Tureckova, Jolana; Iatsiuk, Veronika; Weissmann, Anne; Ferrazzi, Fulvia; Kunze, Philipp; et al. (Cellular and Molecular Life Sciences, 2022)
In cancer, the activating transcription factor 2 (ATF2) has pleiotropic functions in cellular responses to growth stimuli, damage, or inflammation. Due to only limited studies, the significance of ATF2 in colorectal cancer (CRC) is not well understood. We report that low ATF2 levels correlated with worse prognosis and tumor aggressiveness in CRC patients. NanoString gene expression and ChIP analysis confirmed trophoblast cell surface antigen 2 (TROP2) as a novel inhibitory ATF2 target gene. This inverse correlation was further observed in primary human tumor tissues. Immunostainings revealed that high intratumoral heterogeneity for ATF2 and TROP2 expression was sustained also in liver metastasis. Mechanistically, our in vitro data of CRISPR/Cas9-generated ATF2 knockout (KO) clones revealed that high TROP2 levels were critical for cell de-adhesion and increased cell migration without triggering EMT. TROP2 was enriched in filopodia and displaced Paxillin from adherens junctions. In vivo imaging, micro-computer tomography, and immunostainings verified that an ATF2(KO)/TROP2(high) status triggered tumor invasiveness in in vivo mouse and chicken xenograft models. In silico analysis provided direct support that ATF2(low)/TROP2(high) expression status defined high-risk CRC patients. Finally, our data demonstrate that ATF2 acts as a tumor suppressor by inhibiting the cancer driver TROP2. Therapeutic TROP2 targeting might prevent particularly the first steps in metastasis, i.e., the de-adhesion and invasion of colon cancer cells.
CRIS-Team WoS Importer:2022-07-29

A tissue restricted cAMP transcriptional response: SOX10 modulates MSH-triggered expression of MITF in melanocytes. - Wegner, Michael; et al. (Journal of Biological Chemistry, 2003)
UnivIS-Import:2015-03-09:Pub.2003.med.IB.LPCIPDBI.atissu

A Transgenic Mouse Line Expressing the Red Fluorescent Protein tdTomato in GABAergic Neurons - Besser, Stefanie; Sicker, Marit; Marx, Grit; Winkler, Ulrike; Eulenburg, Volker; Huelsmann, Swen; Hirrlinger, Johannes (PLoS ONE, 2015)
GABAergic inhibitory neurons are a large population of neurons in the central nervous system (CNS) of mammals and crucially contribute to the function of the circuitry of the brain. To identify specific cell types and investigate their functions labelling of cell populations by transgenic expression of fluorescent proteins is a powerful approach. While a number of mouse lines expressing the green fluorescent protein (GFP) in different subpopulations of GABAergic cells are available, GFP expressing mouse lines are not suitable for either crossbreeding to other mouse lines expressing GFP in other cell types or for Ca2+-imaging using the superior green Ca2+-indicator dyes. Therefore, we have generated a novel transgenic mouse line expressing the red fluorescent protein tdTomato in GABAergic neurons using a bacterial artificial chromosome based strategy and inserting the tdTomato open reading frame at the start codon within exon 1 of the GAD2 gene encoding glutamic acid decarboxylase 65 (GAD65). TdTomato expression was observed in all expected brain regions; however, the fluorescence intensity was highest in the olfactory bulb and the striatum. Robust expression was also observed in cortical and hippocampal neurons, Purkinje cells in the cerebellum, amacrine cells in the retina as well as in cells migrating along the rostral migratory stream. In cortex, hippocampus, olfactory bulb and brainstem, 80% to 90% of neurons expressing endogenous GAD65 also expressed the fluorescent protein. Moreover, almost all tdTomato-expressing cells coexpressed GAD65, indicating that indeed only GABAergic neurons are labelled by tdTomato expression. This mouse line with its unique spectral properties for labelling GABAergic neurons will therefore be a valuable new tool for research addressing this fascinating cell type.
EVALuna2:4724

A unique role for DNA (hydroxy)methylation in epigenetic regulation of human inhibitory neurons - Kozlenkov, Alexey; Li, Junhao; Apontes, Pasha; Hurd, Yasmin L.; Byne, William M.; Koonin, Eugene; Wegner, Michael; Mukamel, Eran A.; Dracheva, Stella (Science Advances, 2018)
Brain function depends on interaction of diverse cell types whose gene expression and identity are defined, in part, by epigenetic mechanisms. Neuronal DNA contains two major epigenetic modifications, methylcytosine (mC) and hydroxymethylcytosine (hmC), yet their cell type-specific landscapes and relationship with gene expression are poorly understood. We report high-resolution (h)mC analyses, together with transcriptome and histone modification profiling, in three major cell types in human prefrontal cortex: glutamatergic excitatory neurons, medial ganglionic eminence-derived γ-aminobutyric acid (GABA)ergic inhibitory neurons, and oligodendrocytes. We detected a unique association between hmC and gene expression in inhibitory neurons that differed significantly from the pattern in excitatory neurons and oligodendrocytes. We also found that risk loci associated with neuropsychiatric diseases were enriched near regions of reduced hmC in excitatory neurons and reduced mC in inhibitory neurons. Our findings indicate differential roles for mC and hmC in regulation of gene expression in different brain cell types, with implications for the etiology of human brain diseases.
EVALuna2:35739

Autoantibodies Recognizing Secondary NEcrotic Cells Promote Neutrophilic Phagocytosis and Identify Patients With Systemic Lupus Erythematosus - Biermann, Mona; Boeltz, Sebastian; Pieterse, Elmar; Knopf, Jasmin; Rech, Jürgen; Bilyy, Rostyslav; Van Der Vlag, Johan; Tincani, Angela; Distler, Jörg; Krönke, Gerhard; Schett, Georg; Herrmann, Martin; et al. (Frontiers in Immunology, 2018)
Deficient clearance of apoptotic cells reportedly contributes to the etiopathogenesis of the autoimmune disease systemic lupus erythematosus (SLE). Based on this knowledge, we developed a highly specific and sensitive test for the detection of SLE autoantibodies (AAb) utilizing secondary NEcrotic cell (SNEC)-derived material as a substrate. The goal of the present study was to validate the use of SNEC as an appropriate antigen for the diagnosis of SLE in large cohort of patients. We confirmed the presence of apoptotically modified autoantigens on SNEC (dsDNA, high mobility group box 1 protein, apoptosis-associated chromatin modifications, e.g., histones H3-K27-me3; H2A/H4 AcK8,12,16; and H2B-AcK12). Anti-SNEC AAb were measured in the serum of 155 patients with SLE, 89 normal healthy donors (NHD), and 169 patients with other autoimmune connective tissue diseases employing SNEC-based indirect enzyme-linked immunosorbent assay (SNEC ELISA). We compared the test performance of SNEC ELISA with the routine diagnostic tests dsDNA Farr radioimmunoassay (RIA) and nucleosome-based ELISA (anti-dsDNA-NcX-ELISA). SNEC ELISA distinguished patients with SLE with a specificity of 98.9% and a sensitivity of 70.6% from NHD clearly surpassing RIA and anti-dsDNA-NcX-ELISA. In contrast to the other tests, SNEC ELISA significantly discriminated patients with SLE from patients with rheumatoid arthritis, primary anti-phospholipid syndrome, spondyloarthropathy, psoriatic arthritis, and systemic sclerosis. A positive test result in SNEC ELISA significantly correlated with serological variables and reflected the uptake of opsonized SNEC by neutrophils. This stresses the relevance of SNECs in the pathogenesis of SLE. We conclude that SNEC ELISA allows for the sensitive detection of pathologically relevant AAb, enabling its diagnostic usage. A positive SNEC test reflects the opsonization of cell remnants by AAb, the neutrophil recruitment to tissues, and the enhancement of local and systemic inflammatory responses.
EVALuna2:34144

Autophagy inhibition promotes SNCA/alpha-synuclein release and transfer via extracellular vesicles with a hybrid autophagosome-exosome-like phenotype - Minakaki, Georgia; Menges, Stefanie; Kittel, Agnes; Emmanouilidou, Evangelia; Schäffner, Iris; Barkovits, Katalin; Bergmann, Anna; Rockenstein, Edward; Adame, Anthony; Marxreiter, Franz; Mollenhauer, Brit; Galasko, Douglas; et al. (Autophagy, 2017)
The autophagy-lysosome pathway (ALP) regulates intracellular homeostasis of the cytosolic protein SNCA/alpha-synuclein and is impaired in synucleinopathies, including Parkinson disease and dementia with Lewy bodies (DLB). Emerging evidence suggests that ALP influences SNCA release, but the underlying cellular mechanisms are not well understood. Several studies identified SNCA in exosome/extracellular vesicle (EV) fractions. EVs are generated in the multivesicular body compartment and either released upon its fusion with the plasma membrane, or cleared via the ALP. We therefore hypothesized that inhibiting ALP clearance 1) enhances SNCA release via EVs by increasing extracellular shuttling of multivesicular body contents, 2) alters EV biochemical profile, and 3) promotes SNCA cell-to-cell transfer. Indeed, ALP inhibition increased the ratio of extra- to intracellular SNCA and upregulated SNCA association with EVs in neuronal cells. Ultrastructural analysis revealed a widespread, fused multivesicular body-autophagosome compartment. Biochemical characterization revealed the presence of autophagosome-related proteins, such as LC3-II and SQSTM1. This distinct "autophagosome-exosome-like" profile was also identified in human cerebrospinal fluid (CSF) EVs. After a single intracortical injection of SNCA-containing EVs derived from CSF into mice, human SNCA colocalized with endosome and neuronal markers. Prominent SNCA immunoreactivity and a higher number of neuronal SNCA inclusions were observed after DLB patient CSF EV injections. In summary, this study provides compelling evidence that a) ALP inhibition increases SNCA in neuronal EVs, b) distinct ALP components are present in EVs, and c) CSF EVs transfer SNCA from cell to cell in vivo. Thus, macroautophagy/autophagy may regulate EV protein composition and consequently progression in synucleinopathies.
EVALuna2:4781

Autophagy modulates SNCA/?-synuclein release, thereby generating a hostile microenvironment - Pöhler, Anne-Maria; Xiang, Wei; Spitzer, Philipp; May, Verena Elisabeth Luise; Meixner, Holger; Rockenstein, Edward; Chutna, Oldriska; Outeiro, Tiago Fleming; Winkler, Jürgen; Masliah, Eliezer; Klucken, Jochen; Klucken, Jochen (Autophagy, 2014)
SNCA/?-synuclein aggregation plays a crucial role in synucleinopathies such as Parkinson disease and dementia with Lewy bodies. Aggregating and nonaggregating SNCA species are degraded by the autophagy-lysosomal pathway (ALP). Previously, we have shown that the ALP is not only responsible for SNCA degradation but is also involved in the intracellular aggregation process of SNCA. An additional role of extracellular SNCA in the pathology of synucleinopathies substantiating a prion-like propagation hypothesis has been suggested since released SNCA species and spreading of SNCA pathology throughout neural cells have been observed. However, the molecular interplay between intracellular pathways, SNCA aggregation, release, and response of the local microenvironment remains unknown. Here, we attributed SNCA-induced toxicity mainly to secreted species in a cell culture model of SNCA aggregation and in SNCA transgenic mice: We showed that ALP inhibition by bafilomycinA1 reduced intracellular SNCA aggregation but increased secretion of smaller oligomers that exacerbated microenvironmental response including uptake, inflammation, and cellular damage. Low-aggregated SNCA was predominantly released by exosomes and RAB11A-associated pathways whereas high-aggregated SNCA was secreted by membrane shedding. In summary, our study revealed a novel role of the ALP by linking protein degradation to nonclassical secretion for toxic SNCA species. Thus, impaired ALP in the diseased brain not only limits intracellular degradation of misfolded proteins, but also leads to a detrimental microenvironmental response due to enhanced SNCA secretion. These findings suggest that the major toxic role of SNCA is related to its extracellular species and further supports a protective role of intracellular SNCA aggregation.
EVALuna2:4698

Autosomal-Recessive Mutations in the tRNA Splicing Endonuclease Subunit TSEN15 Cause Pontocerebellar Hypoplasia and Progressive Microcephaly - Breuss, Martin W.; Sultan, Tipu; James, Kiely N.; Rosti, Rasim O.; Scott, Eric; Musaev, Damir; Furia, Bansri; Reis, André; Sticht, Heinrich; Al-Owain, Mohammed; Alkuraya, Fowzan S.; Reuter, Miriam; et al. (American Journal of Human Genetics, 2016)
The tRNA splicing endonuclease is a highly evolutionarily conserved protein complex, involved in the cleavage of intron-containing tRNAs. In human it consists of the catalytic subunits TSEN2 and TSEN34, as well as the non-catalytic TSEN54 and TSEN15. Recessive mutations in the corresponding genes of the first three are known to cause pontocerebellar hypoplasia (PCH) types 2A-C, 4, and 5. Here, we report three homozygous TSEN15 variants that cause a milder version of PCH2. The affected individuals showed progressive microcephaly, delayed developmental milestones, intellectual disability, and, in two out of four cases, epilepsy. None, however, displayed the central visual failure seen in PCH case subjects where other subunits of the TSEN are mutated, and only one was affected by the extensive motor defects that are typical in other forms of PCH2. The three amino acid substitutions impacted the protein level of TSEN15 and the stoichiometry of the interacting subunits in different ways, but all resulted in an almost complete loss of in vitro tRNA cleavage activity. Taken together, our results demonstrate that mutations in any known subunit of the TSEN complex can cause PCH and progressive microcephaly, emphasizing the importance of its function during brain development.
EVALuna2:9333

A web tool for the oligodendrocyte differentiation data and network analysis - Cantone, Martina; Eberhardt, Martin; Küspert, Melanie; Reiprich, Simone; Wegner, Michael; Vera, Julio (2017)
EVALuna2:33481

A Xanthohumol-Rich Hop Extract Diminishes Endotoxin-Induced Activation of TLR4 Signaling in Human Peripheral Blood Mononuclear Cells: A Study in Healthy Women - Jung, Finn; Staltner, Raphaela; Baumann, Anja; Burger, Katharina; Halilbasic, Emina; Hellerbrand, Claus; Bergheim, Ina (International Journal of Molecular Sciences, 2022)
Infections with Gram-negative bacteria are still among the leading causes of infection-related deaths. Several studies suggest that the chalcone xanthohumol (XN) found in hop (Humulus lupulus) possesses anti-inflammatory effects. In a single-blinded, placebo controlled randomized cross-over design study we assessed if the oral intake of a single low dose of 0.125 mg of a XN derived through a XN-rich hop extract (75% XN) affects lipopolysaccharide (LPS)-induced immune responses in peripheral blood mononuclear cells (PBMCs) ex vivo in normal weight healthy women (n = 9) (clinicaltrials.gov: NCT04847193) and determined associated molecular mechanisms. LPS-stimulation of PBMCs isolated from participants 1 h after the intake of the placebo for 2 h resulted in a significant induction of pro-inflammatory cytokine release which was significantly attenuated when participants had consumed XN. The XN-dependent attenuation of proinflammatory cytokine release was less pronounced 6 h after the LPS stimulation while the release of sCD14 was significantly reduced at this timepoint. The LPS-dependent activation of hTLR4 transfected HEK293 cells was significantly and dose-dependently suppressed by the XN-rich hop extract which was attenuated when cells were co-challenged with sCD14. Taken together, our results suggest even a one-time intake of low doses of XN consumed in a XN-rich hop extract can suppress LPS-dependent stimulation of PBMCs and that this is related to the interaction of the hop compound with the CD14/TLR4 signaling cascade.
CRIS-Team Scopus Importer:2022-11-11
Keywords: CD14; hop; inflammation; LPS; TLR4

Band 4.1 proteins are expressed in the retina and interact with both isoforms of the metabotropic glutamate receptor type 8. - Rose, Melanie; Dütting, E.; Enz, Ralf (Journal of Neurochemistry, 2008)
The function of the CNS depends on the correct regulation of neurotransmitter receptors by interacting proteins. Here, we screened a retinal cDNA library for proteins interacting with the intracellular C-terminus of the metabotropic glutamate receptor isoform 8a (mGluR8a). The band 4.1B protein binds to the C-termini of mGluR8a and mGluR8b, co-localizes with these glutamate receptors in transfected mammalian cells, facilitates their cell surface expression and inhibits the mGluR8 mediated reduction of intracellular cAMP concentrations. In contrast, no interaction with 4.1B was observed for other mGluRs tested. Amino acids encoded by exons 19 and 20 of 4.1B and a stretch of four basic amino acids present in the mGluR8 C-termini mediate the protein interaction. Besides binding to 4.1B, mGluR8 isoforms interact with 4.1G, 4.1N, and 4.1R. Because band 4.1 transcripts undergo extensive alternative splicing, we analyzed the splicing pattern of interacting regions and detected a 4.1B isoform expressed specifically in the retina. Within this tissue, mGluR8 and 4.1B, 4.1G, 4.1N, and 4.1R show a comparable distribution, being expressed in both synaptic layers and in somata of the ganglion cell layer. In summary, our studies identified band 4.1 proteins as new players for the mGluR8 mediated signal transduction. © 2008 The Authors.
UnivIS-Import:2017-12-18:Pub.2008.med.IB.profes_1.band41
Keywords: Alternative splicing; Protein interaction; Retina; Synaptic signal complex

B cell repertoire analysis identifies new antigenic domains on glycoprotein B of human cytomegalovirus which are target of neutralizing antibodies - Pötzsch, Sonja; Spindler, Nadja; Wiegers, Anna-Katharina; Fisch, Tanja; Ruecker, Pia; Sticht, Heinrich; Grieb, Nina; Baroti, Tina; Weisel, Florian; Stamminger, Thomas; Martin-Parras, Luis; Mach, Michael; et al. (PLoS Pathogens, 2011)
Human cytomegalovirus (HCMV), a herpesvirus, is a ubiquitously distributed pathogen that causes severe disease in immunosuppressed patients and infected newborns. Efforts are underway to prepare effective subunit vaccines and therapies including antiviral antibodies. However, current vaccine efforts are hampered by the lack of information on protective immune responses against HCMV. Characterizing the B-cell response in healthy infected individuals could aid in the design of optimal vaccines and therapeutic antibodies. To address this problem, we determined, for the first time, the B-cell repertoire against glycoprotein B (gB) of HCMV in different healthy HCMV seropositive individuals in an unbiased fashion. HCMV gB represents a dominant viral antigenic determinant for induction of neutralizing antibodies during infection and is also a component in several experimental HCMV vaccines currently being tested in humans. Our findings have revealed that the vast majority (>90%) of gB-specific antibodies secreted from B-cell clones do not have virus neutralizing activity. Most neutralizing antibodies were found to bind to epitopes not located within the previously characterized antigenic domains (AD) of gB. To map the target structures of these neutralizing antibodies, we generated a 3D model of HCMV gB and used it to identify surface exposed protein domains. Two protein domains were found to be targeted by the majority of neutralizing antibodies. Domain I, located between amino acids (aa) 133-343 of gB and domain II, a discontinuous domain, built from residues 121-132 and 344-438. Analysis of a larger panel of human sera from HCMV seropositive individuals revealed positivity rates of >50% against domain I and >90% against domain II, respectively. In accordance with previous nomenclature the domains were designated AD-4 (Dom II) and AD-5 (Dom I), respectively. Collectively, these data will contribute to optimal vaccine design and development of antibodies effective in passive immunization. © 2011 Pötzsch et al.
EVALuna2:8099

beta(2)-m - a Trigger for NLRP3 Inflammasome Activation within Macrophages Promoting Multiple Myeloma Cell Proliferation - Hofbauer, Daniel; Mougiakakos, Dimitrios; Büttner-Herold, Maike; Neumann, Frank; Nolting, Jens; Bisht, Savita; Zeiser, Robert; Hamarsheh, Shaima'A; Ricagno, Stefano; Zaiss, Mario; Eberhardt, Martin; Böttcher, Martin; et al. (BLOOD, 2019)
CRIS-Team WoS Importer:2021-10-18

Bi-allelic loss-of-function variants in PPFIBP1 cause a neurodevelopmental disorder with microcephaly, epilepsy, and periventricular calcifications - Rosenhahn, Erik; O'Brien, Thomas J.; Zaki, Maha S.; Sorge, Ina; Wieczorek, Dagmar; Rostasy, Kevin; Vitobello, Antonio; Nambot, Sophie; Alkuraya, Fowzan S.; Hashem, Mais O.; Alhashem, Amal; Tabarki, Brahim; et al. (American Journal of Human Genetics, 2022)
PPFIBP1 encodes for the liprin-β1 protein, which has been shown to play a role in neuronal outgrowth and synapse formation in Drosophila melanogaster. By exome and genome sequencing, we detected nine ultra-rare homozygous loss-of-function variants in 16 individuals from 12 unrelated families. The individuals presented with moderate to profound developmental delay, often refractory early-onset epilepsy, and progressive microcephaly. Further common clinical findings included muscular hyper- and hypotonia, spasticity, failure to thrive and short stature, feeding difficulties, impaired vision, and congenital heart defects. Neuroimaging revealed abnormalities of brain morphology with leukoencephalopathy, ventriculomegaly, cortical abnormalities, and intracranial periventricular calcifications as major features. In a fetus with intracranial calcifications, we identified a rare homozygous missense variant that by structural analysis was predicted to disturb the topology of the SAM domain region that is essential for protein-protein interaction. For further insight into the effects of PPFIBP1 loss of function, we performed automated behavioral phenotyping of a Caenorhabditis elegans PPFIBP1/hlb-1 knockout model, which revealed defects in spontaneous and light-induced behavior and confirmed resistance to the acetylcholinesterase inhibitor aldicarb, suggesting a defect in the neuronal presynaptic zone. In conclusion, we establish bi-allelic loss-of-function variants in PPFIBP1 as a cause of an autosomal recessive severe neurodevelopmental disorder with early-onset epilepsy, microcephaly, and periventricular calcifications.
CRIS-Team Scopus Importer:2022-08-19

Biallelic SEMA3A defects cause a novel type of syndromic short stature - Hofmann, Kristin; Zweier, Markus; Sticht, Heinrich; Zweier, Christiane; Wittmann, Wolfgang; Hoyer, Juliane; Uebe, Steffen; Van Haeringen, Arie; Thiel, Christian; Ekici, Arif Bülent; Reis, André; Rauch, Anita (American Journal of Medical Genetics Part A, 2013)
Chromosomal microarray testing is commonly used to identify disease causing de novo copy number variants in patients with developmental delay and multiple congenital anomalies. In such a patient we now observed an 150 kb deletion on chromosome 7q21.11 affecting the first exon of the axon guidance molecule gene SEMA3A (sema domain, immunoglobulin domain (Ig), short basic domain, secreted, (semaphorin) 3A). This deletion was inherited from the healthy father, but considering the function of SEMA3A and phenotypic similarity to the knock-out mice, we still assumed a pathogenic relevance and tested for a recessive second defect. Sequencing of SEMA3A in the patient indeed revealed the de novo in-frame mutation p.Phe316_Lys317delinsThrSerSerAsnGlu. Cloning of the mutated allele in combination with two informative SNPs confirmed compound heterozygosity in the patient. While the altered protein structure was predicted to be benign, aberrant splicing resulting in a premature stop codon was proven by RT-PCR to occur in about half of the transcripts from this allele. Expression profiling in human fetal and adult cDNA panels, confirmed a high expression of SEMA3A in all brain regions as well as in adult and fetal heart and fetal skeletal muscle. Normal intellectual development in the patient was surprising but may be explained by the remaining 20% of SEMA3A expression level demonstrated by quantitative RT-PCR. We therefore report a novel autosomal recessive syndrome characterized by postnatal short stature with relative macrocephaly, camptodactyly, septal heart defect and several minor anomalies caused by biallelic mutations in SEMA3A.
EVALuna2:9194

Bi-allelic variants in CHKA cause a neurodevelopmental disorder with epilepsy and microcephaly - Kloeckner, Chiara; Murray, J. Pedro Fernandez; Tavasoli, Mahtab; Sticht, Heinrich; Stoltenburg-Didinger, Gisela; Scholle, Leila Motlagh; Bakhtiari, Somayeh; Kruer, Michael C.; Darvish, Hossein; Firouzabadi, Saghar Ghasemi; Pagnozzi, Alex; Shukla, Anju; et al. (Brain, 2022)
The Kennedy pathways catalyse the de novo synthesis of phosphatidylcholine and phosphatidylethanolamine, the most abundant components of eukaryotic cell membranes. In recent years, these pathways have moved into clinical focus because four of ten genes involved have been associated with a range of autosomal recessive rare diseases such as a neurodevelopmental disorder with muscular dystrophy (CHKB), bone abnormalities and cone-rod dystrophy (PCYT1A) and spastic paraplegia (PCYT2, SELENOI). We identified six individuals from five families with bi-allelic variants in CHKA presenting with severe global developmental delay, epilepsy, movement disorders and microcephaly. Using structural molecular modelling and functional testing of the variants in a cell-based Saccharomyces cerevisiae model, we determined that these variants reduce the enzymatic activity of CHKA and confer a significant impairment of the first enzymatic step of the Kennedy pathway. In summary, we present CHKA as a novel autosomal recessive gene for a neurodevelopmental disorder with epilepsy and microcephaly.
CRIS-Team WoS Importer:2022-06-17

Bi-allelic variants in SPATA5L1 lead to intellectual disability, spastic-dystonic cerebral palsy, epilepsy, and hearing loss - Richard, Elodie M.; Bakhtiari, Somayeh; Marsh, Ashley P.L.; Kaiyrzhanov, Rauan; Wagner, Matias; Shetty, Sheetal; Pagnozzi, Alex; Nordlie, Sandra M.; Guida, Brandon S.; Cornejo, Patricia; Magee, Helen; Liu, James; et al. (American Journal of Human Genetics, 2021)
Spermatogenesis-associated 5 like 1 (SPATA5L1) represents an orphan gene encoding a protein of unknown function. We report 28 bi-allelic variants in SPATA5L1 associated with sensorineural hearing loss in 47 individuals from 28 (26 unrelated) families. In addition, 25/47 affected individuals (53%) presented with microcephaly, developmental delay/intellectual disability, cerebral palsy, and/or epilepsy. Modeling indicated damaging effect of variants on the protein, largely via destabilizing effects on protein domains. Brain imaging revealed diminished cerebral volume, thin corpus callosum, and periventricular leukomalacia, and quantitative volumetry demonstrated significantly diminished white matter volumes in several individuals. Immunofluorescent imaging in rat hippocampal neurons revealed localization of Spata5l1 in neuronal and glial cell nuclei and more prominent expression in neurons. In the rodent inner ear, Spata5l1 is expressed in the neurosensory hair cells and inner ear supporting cells. Transcriptomic analysis performed with fibroblasts from affected individuals was able to distinguish affected from controls by principal components. Analysis of differentially expressed genes and networks suggested a role for SPATA5L1 in cell surface adhesion receptor function, intracellular focal adhesions, and DNA replication and mitosis. Collectively, our results indicate that bi-allelic SPATA5L1 variants lead to a human disease characterized by sensorineural hearing loss (SNHL) with or without a nonprogressive mixed neurodevelopmental phenotype.
CRIS-Team Scopus Importer:2021-10-22
Keywords: AAA+ superfamily; ATPase; cerebral palsy; epilepsy; intellectual disability; movement disorder; neurodevelopmental disorder; sensorineural hearing loss; SPATA5L1

Binding of histamine to the H1 receptora molecular dynamics study - Söldner, Christian; Horn, Anselm; Sticht, Heinrich (Journal of Molecular Modeling, 2018)
Binding of histamine to the G-protein coupled histamine H-1 receptor plays an important role in the context of allergic reactions; however, no crystal structure of the resulting complex is available yet. To deduce the histamine binding site, we performed unbiased molecular dynamics (MD) simulations on a microsecond time scale, which allowed to monitor one binding event, in which particularly the residues of the extracellular loop 2 were involved in the initial recognition process. The final histamine binding pose in the orthosteric pocket is characterized by interactions with Asp107(3.32), Tyr108(3.33), Thr194(5.43), Asn198(5.46), Trp428(6.48), Tyr431(6.51), Phe432(6.52), and Phe435(6.55), which is in agreement with existing mutational data. The conformational stability of the obtained complex structure was subsequently confirmed in 2 s equilibrium MD simulations, and a metadynamics simulation proved that the detected binding site represents an energy minimum. A complementary investigation of a D107A mutant, which has experimentally been shown to abolish ligand binding, revealed that this exchange results in a significantly weaker interaction and enhanced ligand dynamics. This finding underlines the importance of the electrostatic interaction between the histamine ammonium group and the side chain of Asp107(3.32) for histamine binding.
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Binding partners of metabotropic glutamate receptors. - Enz, Ralf (Molecular aspects of G protein-coupled receptors: Interacting proteins and function, 2008)
UnivIS-Import:2017-12-18:Pub.2008.med.IB.profes_1.bindin

Binding properties of SUMO-interacting motifs (SIMs) in yeast - Jardin, Christophe; Horn, Anselm; Sticht, Heinrich (Journal of Molecular Modeling, 2015)
Small ubiquitin-like modifier (SUMO) conjugation and interaction play an essential role in many cellular processes. A large number of yeast proteins is known to interact non-covalently with SUMO via short SUMO-interacting motifs (SIMs), but the structural details of this interaction are yet poorly characterized. In the present work, sequence analysis of a large dataset of 148 yeast SIMs revealed the existence of a hydrophobic core binding motif and a preference for acidic residues either within or adjacent to the core motif. Thus the sequence properties of yeast SIMs are highly similar to those described for human. Molecular dynamics simulations were performed to investigate the binding preferences for four representative SIM peptides differing in the number and distribution of acidic residues. Furthermore, the relative stability of two previously observed alternative binding orientations (parallel, antiparallel) was assessed. For all SIMs investigated, the antiparallel binding mode remained stable in the simulations and the SIMs were tightly bound via their hydrophobic core residues supplemented by polar interactions of the acidic residues. In contrary, the stability of the parallel binding mode is more dependent on the sequence features of the SIM motif like the number and position of acidic residues or the presence of additional adjacent interaction motifs. This information should be helpful to enhance the prediction of SIMs and their binding properties in different organisms to facilitate the reconstruction of the SUMO interactome.
EVALuna2:26291

Blood-borne phagocytes internalize urate microaggregates and prevent intravascular NETosis by urate crystals - Pieterse, Elmar; Jeremic, Ivica; Czegley, Christine; Weidner, Daniela; Biermann, Mona; Veissi, Susan; Maueröder, Christian; Schauer, Christine; Bilyy, Rostyslav; Dumych, Tetiana; Hoffmann, Markus; Munoz, Luis Enrique; et al. (Scientific Reports, 2016)
Hyperuricemia is strongly linked to cardiovascular complications including atherosclerosis and thrombosis. In individuals with hyperuricemia, needle-shaped monosodium urate crystals (nsMSU) frequently form within joints or urine, giving rise to gouty arthritis or renal calculi, respectively. These nsMSU are potent instigators of neutrophil extracellular trap (NET) formation. Little is known on the mechanism(s) that prevent nsMSU formation within hyperuricemic blood, which would potentially cause detrimental consequences for the host. Here, we report that complement proteins and fetuins facilitate the continuous clearance by blood-borne phagocytes and resident macrophages of small urate microaggregates (UMA; <1 ?m in size) that initially form in hyperuricemic blood. If this clearance fails, UMA exhibit bipolar growth to form typical full-sized nsMSU with a size up to 100 ?m. In contrast to UMA, nsMSU stimulated neutrophils to release NETs. Under conditions of flow, nsMSU and NETs formed densely packed DNase I-resistant tophus-like structures with a high obstructive potential, highlighting the importance of an adequate and rapid removal of UMA from the circulation. Under pathological conditions, intravascularly formed nsMSU may hold the key to the incompletely understood association between NET-driven cardiovascular disease and hyperuricemia.
EVALuna2:13377

BMP6-induced modulation of the tumor micro-milieu - Stieglitz, David; Lamm, Susanne; Braig, Simone; Feuerer, Lena; Kuphal, Silke; Dietrich, Peter; Arndt, Stephanie; Echtenacher, Bernd; Hellerbrand, Claus; Karrer, Sigrid; Boßerhoff, Anja Katrin (Oncogene, 2019)
Melanoma is the deadliest form of skin cancer with rising incidence, creating a significant health problem. We discovered increased expression of bone morphogenetic protein 6 (BMP6) in melanoma cells and tissues, and observed that BMP6 deficiency caused significantly delayed tumor onset and decelerated tumor progression in a melanoma mouse model. Moreover, we determined that BMP6 inhibits dermal mast cell recruitment and found that mast cell-derived mediators significantly reduced melanoma growth in vitro. In line with this, mast cell deficiency accelerated tumor onset and progression in a melanoma mouse model. Analysis of human melanoma tissues revealed a strong negative correlation between melanoma proliferation and mast cell infiltration. This study elucidates a novel role of BMP6-induced modulation of the tumor microenvironment.
EVALuna2:106826

BMP-9 interferes with liver regeneration and promotes liver fibrosis - Breitkopf-Heinlein, Katja; Meyer, Christoph; Koenig, Courtney; Gaitantzi, Haristi; Addante, Annalisa; Thomas, Maria; Wiercinska, Eliza; Cai, Chen; Li, Qi; Wan, Fengqi; Hellerbrand, Claus; Valous, Nektarios A.; et al. (Gut, 2017)
Bone morphogenetic protein (BMP)-9, a member of the transforming growth factor-? family of cytokines, is constitutively produced in the liver. Systemic levels act on many organs and tissues including bone and endothelium, but little is known about its hepatic functions in health and disease.Levels of BMP-9 and its receptors were analysed in primary liver cells. Direct effects of BMP-9 on hepatic stellate cells (HSCs) and hepatocytes were studied in vitro, and the role of BMP-9 was examined in acute and chronic liver injury models in mice.Quiescent and activated HSCs were identified as major BMP-9 producing liver cell type. BMP-9 stimulation of cultured hepatocytes inhibited proliferation, epithelial to mesenchymal transition and preserved expression of important metabolic enzymes such as cytochrome P450. Acute liver injury caused by partial hepatectomy or single injections of carbon tetrachloride (CCl4) or lipopolysaccharide (LPS) into mice resulted in transient downregulation of hepatic BMP-9 mRNA expression. Correspondingly, LPS stimulation led to downregulation of BMP-9 expression in cultured HSCs. Application of BMP-9 after partial hepatectomy significantly enhanced liver damage and disturbed the proliferative response. Chronic liver damage in BMP-9-deficient mice or in mice adenovirally overexpressing the selective BMP-9 antagonist activin-like kinase 1-Fc resulted in reduced deposition of collagen and subsequent fibrosis.Constitutive expression of low levels of BMP-9 stabilises hepatocyte function in the healthy liver. Upon HSC activation, endogenous BMP-9 levels increase in vitro and in vivo and high levels of BMP-9 cause enhanced damage upon acute or chronic injury.
EVALuna2:4778

BMP-9 Modulates the Hepatic Responses to LPS - Gaitantzi, Haristi; Karch, Julius; Germann, Lena; Cai, Chen; Rausch, Vanessa; Birgin, Emrullah; Rahbari, Nuh; Seitz, Tatjana; Hellerbrand, Claus; Koenig, Courtney; Augustin, Hellmut G.; Mogler, Carolin; et al. (Cells, 2020)
It was previously shown that Bone Morphogenetic Protein (BMP)-9 is constitutively produced and secreted by hepatic stellate cells (HSC). Upon acute liver damage, BMP-9 expression is transiently down-regulated and blocking BMP-9 under conditions of chronic damage ameliorated liver fibrogenesis in C57BL/6 mice. Thereby, BMP-9 acted as a pro-fibrogenic cytokine in the liver but without directly activating isolated HSC in vitro. Lipopolysaccharide (LPS), an endotoxin derived from the membrane of Gram-negative bacteria in the gut, is known to be essential in the pathogenesis of diverse kinds of liver diseases. The aim of the present project was therefore to investigate how high levels of BMP-9 in the context of LPS signalling might result in enhanced liver damage. For this purpose, we stimulated human liver sinusoidal endothelial cells (LSEC) with LPS and incubated primary human liver myofibroblasts (MF) with the conditioned medium of these cells. We found that LPS led to the secretion of factors from LSEC that upregulate BMP-9 expression in MF. At least one of these BMP-9 enhancing factors was defined to be IL-6. High BMP-9 in turn, especially in combination with LPS stimulation, induced the expression of certain capillarization markers in LSEC and enhanced the LPS-mediated induction of pro-inflammatory cytokines in primary human macrophages. In LSEC, pre-treatment with BMP-9 reduced the LPS-mediated activation of the NfkB pathway, whereas in macrophages, LPS partially inhibited the BMP-9/Smad-1 signaling cascade. In vivo, in mice, BMP-9 led to the enhanced presence of F4/80-positive cells in the liver and it modulated the LPS-mediated regulation of inflammatory mediators. In summary, our data point to BMP-9 being a complex and highly dynamic modulator of hepatic responses to LPS: Initial effects of LPS on LSEC led to the upregulation of BMP-9 in MF but sustained high levels of BMP-9 in turn promote pro-inflammatory reactions of macrophages. Thereby, the spatial and timely fine-tuned presence (or absence) of BMP-9 is needed for efficient wound-healing responses in the liver.
CRIS-Team WoS Importer:2020-05-15

BMP and WNT signalling cooperate through LEF1 in the neuronal specification of adult hippocampal neural stem and progenitor cells. - Armenteros, Tomas; Andreu, Zoraida; Hortiguela, Rafael; Lie, Dieter Chichung; Mira, Helena (Scientific Reports, 2018)
Neuronal production from neural stem cells persists during adulthood in the subgranular zone of the hippocampal dentate gyrus. Extracellular signals provided by the hippocampal microenvironment regulate the neuronal fate commitment of the stem cell progeny. To date, the identity of those signals and their crosstalk has been only partially resolved. Here we show that adult rat hippocampal neural stem and progenitor cells (AH-NSPCs) express receptors for bone morphogenetic proteins (BMPs) and that the BMP/P-Smad pathway is active in AH-NSPCs undergoing differentiation towards the neuronal lineage. In vitro, exposure to the BMP2 and BMP4 ligands is sufficient to increase neurogenesis from AH-NSPCs in a WNT dependent manner while decreasing oligodendrogenesis. Moreover, BMP2/4 and WNT3A, a key regulator of adult hippocampal neurogenesis, cooperate to further enhance neuronal production. Our data point to a mechanistic convergence of the BMP and WNT pathways at the level of the T-cell factor/lymphoid enhancer factor gene Lef1. Altogether, we provide evidence that BMP signalling is an important regulator for the neuronal fate specification of AH-NSPCs cultures and we show that it significantly cooperates with the previously described master regulator of adult hippocampal neurogenesis, the WNT signalling pathway.
EVALuna2:421422

Bone Morphogenetic Protein 13 Has Protumorigenic Effects on Hepatocellular Carcinoma Cells In Vitro. - Kersten, Vanessa; Seitz, Tatjana; Sommer, Judith; Thasler, Wolfgang E.; Boßerhoff, Anja Katrin; Hellerbrand, Claus (International Journal of Molecular Sciences, 2023)
Activated hepatic stellate cells (HSCs) play a key role in hepatic fibrosis and, thus, build the "soil" for hepatocarcinogenesis. Furthermore, HSCs are known to promote the progression of hepatocellular carcinoma (HCC), but the molecular mechanisms are only incompletely understood. Recently, we newly described the expression of bone morphogenetic protein 13 (BMP13) by HSCs in fibrotic liver tissue. In addition, BMP13 has mostly been studied in the context of cartilage and bone repair, but not in liver disease or cancer. Thus, we aimed to analyze the expression and function of BMP13 in HCC. Expression analyses revealed high BMP13-expression in activated human HSCs, but not in human HCC-cell-lines. Furthermore, analysis of human HCC tissues showed a significant correlation between BMP13 and α-smooth muscle actin (α-SMA), and immunofluorescence staining confirmed the co-localization of BMP13 and α-SMA, indicating activated HSCs as the cellular source of BMP13 in HCC. Stimulation of HCC cells with recombinant BMP13 increased the expression of the inhibitors of differentiation 1 (ID1) and 2 (ID2), which are known targets of BMP-signaling and cell-cycle promotors. In line with this, BMP13-stimulation caused an induced SMAD 1/5/9 and extracellular signal-regulated kinase (ERK) phosphorylation, as well as reduced expression of cyclin-dependent kinase inhibitors 1A (CDKN1A) and 2A (CDKN2A). Furthermore, stimulation with recombinant BMP13 led to increased proliferation and colony size formation of HCC cells in clonogenicity assays. The protumorigenic effects of BMP13 on HCC cells were almost completely abrogated by the small molecule dorsomorphin 1 (DMH1), which selectively blocks the intracellular kinase domain of ALK2 and ALK3, indicating that BMP13 acts via these BMP type I receptors on HCC cells. In summary, this study newly identifies stroma-derived BMP13 as a potential new tumor promotor in HCC and indicates this secreted growth-factor as a possible novel therapeutic target in HCC.
EVALuna2:538506

Bone morphogenetic protein 13 in hepatic stellate cells and hepatic fibrosis - Peschl, Vanessa; Seitz, Tatjana; Sommer, Judith; Thasler, Wolfgang; Boßerhoff, Anja Katrin; Hellerbrand, Claus (Journal of Cellular Biochemistry, 2022)
Hepatic fibrosis can be considered as a deregulated wound healing process in response to chronic liver injury. Bone morphogenetic protein 13 (BMP13) has been described to promote bone and tendon repair. In this study, we aimed to analyze the expression and function of BMP13 in hepatic fibrosis. We found increased BMP13 expression during the activation of hepatic stellate cells (HSCs), which is known as the key event of hepatic fibrosis. Fitting to this, BMP13 was elevated in murine models of hepatic fibrosis, and immunofluorescence staining showed colocalization of BMP13 and α-smooth muscle actin (α-SMA), a marker for activated HSC, in cirrhotic human liver tissue. BMP13 depletion in activated human HSC reduced the phosphorylation of smad1/5/9 and the expression of the transcription factor inhibitor of differentiation 1 (ID1), a known BMP target gene and profibrogenic factor. Furthermore, BMP13-depletion led to reduced proliferation and downregulation of collagen I α1 (COL1A1) and α-SMA, and, interestingly, also reduced phosphorylation of extracellular signal-regulated kinases (ERK). Conversely, stimulation with recombinant BMP13 induced the phosphorylation of smad1/5/9 and ERK, as well as the proliferation and the expression of ID1, COL1A1, and α-SMA in HSCs. These stimulatory effects were inhibited by dorsomorphin 1, a small-molecule inhibitor of the BMP-type I receptors activin receptor-like kinase-2 and -3, which are both expressed by HSC. In summary, these data indicate increased BMP13 expression in hepatic fibrosis as a profibrogenic factor. Thus, this soluble growth factor might have the potential as a new fibrosis marker and antifibrogenic therapeutic target in patients with chronic liver disease.
CRIS-Team Scopus Importer:2022-04-29
Keywords: BMP13; hepatic stellate cells; liver fibrosis

Bone Morphogenetic Protein-6 Inhibits Fibrogenesis in Scleroderma Offering Treatment Options for Fibrotic Skin Disease - Arndt, Stephanie; Karrer, Sigrid; Hellerbrand, Claus; Boßerhoff, Anja Katrin (Journal of Investigative Dermatology, 2019)
BMP6 is known to be crucial for regulating embryonic skin development. This study assessed the role of BMP6 in dermal fibrosis. We detected that BMP6 is significantly increased in skin-derived fibroblasts of patients with localized scleroderma. Moreover, it was shown that BMP6 significantly impacts proliferation, migration, cytoskeletal organization, and collagen expression, as well as activity of the major pro-fibrogenic transcription factor AP-1 in dermal fibroblasts. The importance of BMP6 in dermal fibrosis was further confirmed in an in vivo model of dermal fibrosis in which BMP6-deficient mice showed significantly enhanced fibrosis compared with wild-type mice. Conversely, application of recombinant BMP6 significantly ameliorated dermal fibrosis in this preclinical bleomycin-induced sclerosis model, and herewith provided proof of concept for the successful treatment of this fibrotic skin disease.
CRIS-Team Scopus Importer:2019-05-17

Bone Morphogenetic Protein-8B Expression is Induced in Steatotic Hepatocytes and Promotes Hepatic Steatosis and Inflammation In Vitro - Mahli, Abdo; Seitz, Tatjana; Beckroege, Tobias; Freese, Kim; Thasler, Wolfgang Erwin; Benkert, Matthias; Dietrich, Peter; Weiskirchen, Ralf; Boßerhoff, Anja Katrin; Hellerbrand, Claus (Cells, 2019)
Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic manifestation of the metabolic syndrome. The bone morphogenetic protein-8B (BMP8B) has been shown to be expressed in brown adipose tissues and the hypothalamus and to affect thermogenesis and susceptibility to diet-induced obesity. Here, we aimed to analyze BMP8B expression in NAFLD and to gain insight into BMP8B effects on pathophysiological steps of NAFLD progression. BMP8B mRNA and protein expression were dose-dependently induced in primary human hepatocytes in vitro upon incubation with fatty acids. Furthermore, hepatic BMP8B expression was significantly increased in a murine NAFLD model and in NAFLD patients compared with controls. Incubation with recombinant BMP8B further enhanced the fatty acid-induced cellular lipid accumulation as well as NFB activation and pro-inflammatory gene expression in hepatocytes, while siRNA-mediated BMP8B depletion ameliorated these fatty acid-induced effects. Analysis of the expression of key factors of hepatocellular lipid transport and metabolisms indicated that BMP8B effects on fatty acid uptake as well as de novo lipogenesis contributed to hepatocellular accumulation of fatty acids leading to increased storage in the form of triglycerides and enhanced combustion by beta oxidation. In conclusion, our data indicate that BMP8B enhances different pathophysiological steps of NAFLD progression and suggest BMP8B as a promising prognostic marker and therapeutic target for NAFLD and, potentially, also for other chronic liver diseases.
CRIS-Team WoS Importer:2019-06-28

Bone morphogenetic proteins are required in vivo for the generation of sympathetic neurons - Wegner, Michael; et al. (Neuron, 1999)
Bone morphogenetic proteins (BMPs) induce autonomic neurogenesis in neural crest cultures and stimulate sympathetic neuron development when overexpressed in vivo. We demonstrate that inhibition of BMPs in the chick embryo by the BMP antagonist Noggin prevents sympathetic neuron generation. In Noggin-treated embryos, the noradrenergic marker genes tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DBH), panneuronal neurofilament 160 (NF160) and SCG10 genes, and the transcriptional regulators Phox2b and Phox2a are not expressed in sympathetic ganglia. Whereas initial ganglion development is not affected, the expression of the basic helix-loop-helix transcription factor Cash-1 is strongly reduced. These results demonstrate that BMPs are essential for sympathetic neuron development and establish Cash-1 and Phox2 genes as downstream effectors of BMPs in this lineage.
UnivIS-Import:2015-03-05:Pub.1999.med.IB.LPCIPDBI.bonemo

Bone Tissue Engineering Under Xenogeneic-Free Conditions in a Large Animal Model as a Basis for Early Clinical Applicability - Weigand, Annika; Beier, Justus; Schmid, Rafael; Knorr, Thomas; Kilian, David; Goetzl, Rebekka; Gerber, Thomas; Horch, Raymund E.; Boos, Anja (Tissue Engineering: Parts A, B, and C, 2017)
For decades, researchers have been developing a range of promising strategies in bone tissue engineering with the aim of producing a significant clinical benefit over existing therapies. However, a major problem concerns the traditional use of xenogeneic substances for the expansion of cells, which complicates direct clinical transfer. The study's aim was to establish a totally autologous sheep model as a basis for further preclinical studies and future clinical application. Ovine mesenchymal stromal cells (MSC) were cultivated in different concentrations (0%, 2%, 5%, 10%, and 25%) of either autologous serum (AS) or fetal calf serum (FCS). With an increase of serum concentration, enhanced metabolic activity and proliferation could be observed. There were minor differences between MSC cultivated in AS or FCS, comparing gene and protein expression of osteogenic and stem cell markers, morphology, and osteogenic differentiation. MSC implanted subcutaneously in the sheep model, together with a nanostructured bone substitute, either in stable block or moldable putty form, induced similar vascularization and remodeling of the bone substitute irrespective of cultivation of MSC in AS or FCS and osteogenic differentiation. The bone substitute in block form together with MSC proved particularly advantageous in the induction of ectopic bone formation compared to the cell-free control and putty form. It could be demonstrated that AS is suitable for replacement of FCS for cultivation of ovine MSC for bone tissue engineering purposes. Substantial progress has been made in the development of a strictly xenogeneic-free preclinical animal model to bring future clinical application of bone tissue engineering strategies within reach.
EVALuna2:32847

Brain-derived neurotrophic factor, Val66Met single nucleotide polymorphism is not associated with alcohol dependence - Muschler, Marc Andre Nicolas; Heberlein, Annemarie; Frieling, Helge; Vogel, Nicolas; Becker, Cord-Michael; Kornhuber, Johannes; Bleich, Stefan; Hillemacher, Thomas (Psychiatric Genetics, 2011)
EVALuna2:4656

Brg1-dependent chromatin remodelling is not essentially required during oligodendroglial differentiation - Bischof, Melanie; Weider, Matthias; Küspert, Melanie; Nave, Klaus-Armin; Wegner, Michael (The Journal of Neuroscience, 2015)
Myelinating Schwann cells in the vertebrate peripheral nervous system rely on Brg1 (Smarca4) for terminal differentiation. Brg1 serves as central ATP-hydrolyzing subunit of the chromatin remodelling BAF complexes and is recruited during myelination as part of these complexes by the transcription factor Sox10 in Schwann cells. Here, we analyzed the role of Brg1 during development of myelinating oligodendrocytes in the CNS of the mouse. Following Brg1 deletion in oligodendrocyte precursors, these cells showed normal survival, proliferation, and migration. A mild but significant reduction in the number of oligodendrocytes with myelin gene expression in the absence of Brg1 points to a contribution to oligodendroglial differentiation but also shows that the role of Brg1 is much less prominent than during Schwann cell differentiation. Additionally, we failed to obtain evidence for a genetic interaction between Brg1 and Sox10 comparable with the one in Schwann cells. This argues that similarities exist between the regulatory networks and mechanisms in both types of myelinating glia but that the exact mode of action and the relevance of functional interactions differ, pointing to a surprising degree of variability in the control of myelination.
EVALuna2:4972

BRG1 interacts with SOX10 to establish the melanocyte lineage and to promote differentiation. - Marathe, Himangi G.; Watkins-Chow, Dawn E.; Weider, Matthias; Hoffmann, Alana; Trivedi, Archit; Aras, Shweta; Mehta, Gaurav; Basuroy, Tupa; Mehrotra, Aanchal; Bennett, Dorothy C.; Wegner, Michael; Pavan, William J.; et al. (Nucleic Acids Research, 2017)
Mutations in SOX10 cause neurocristopathies which display varying degrees of hypopigmentation. Using a sensitized mutagenesis screen, we identified Smarca4 as a modifier gene that exacerbates the phenotypic severity ofSox10 haplo-insufficientmice. Conditional deletion of Smarca4 in SOX10 expressing cells resulted in reduced numbers of cranial and ventral trunk melanoblasts. To define the requirement for the Smarca4 -encoded BRG1 subunit of the SWI/SNF chromatin remodeling complex, we employed in vitro models of melanocyte differentiation in which induction of melanocyte-specific gene expression is closely linked to chromatin alterations. We found that BRG1 was required for expression of Dct, Tyrp1 and Tyr, genes that are regulated by SOX10 and MITF and for chromatin remodeling at distal and proximal regulatory sites. SOX10 was found to physically interact with BRG1 in differentiating melanocytes and binding of SOX10 to the Tyrp1 distal enhancer temporally coincided with recruitment of BRG1. Our data show that SOX10 cooperates with MITF to facilitate BRG1 binding to distal enhancers of melanocyte-specific genes. Thus, BRG1 is a SOX10 co-activator, required to establish the melanocyte lineage and promote expression of genes important for melanocyte function.
EVALuna2:33480

Brn3a expression is epigenetically controlled by HDAC2 in melanocytes and melanoma - Heppt, Markus; Wessely, A.; Hornig, E.; Kammerbauer, C.; Graf, S.; Besch, R.; French, L. E.; Kuphal, Silke; Kappelmann-Fenzl, Melanie; Boßerhoff, Anja Katrin; Berking, Carola (EXPERIMENTAL DERMATOLOGY, 2021)
CRIS-Team WoS Importer:2021-05-14

Campylobacter jejuni enters gut epithelial cells and impairs intestinal barrier function through cleavage of occludin by serine protease HtrA - Harrer, Aileen; Buecker, Roland; Böhm, Manja; Zarzecka, Urszula; Tegtmeyer, Nicole; Sticht, Heinrich; Schulzke, Joerg D.; Backert, Steffen (Gut Pathogens, 2019)
Campylobacter jejuni secretes HtrA (high temperature requirement protein A), a serine protease that is involved in virulence. Here, we investigated the interaction of HtrA with the host protein occludin, a tight junction strand component. Immunofluorescence studies demonstrated that infection of polarized intestinal Caco-2 cells with C. jejuni strain 81-176 resulted in a redistribution of occludin away from the tight junctions into the cytoplasm, an effect that was also observed in human biopsies during acute campylobacteriosis. Occludin knockout Caco-2 cells were generated by CRISPR/Cas9 technology. Inactivation of this gene affected the polarization of the cells in monolayers and transepithelial electrical resistance (TER) was reduced, compared to wild-type Caco-2 cells. Although tight junctions were still being formed, occludin deficiency resulted in a slight decrease of the tight junction plaque protein ZO-1, which was redistributed off the tight junction into the lateral plasma membrane. Adherence of C. jejuni to Caco-2 cell monolayers was similar between the occludin knockout compared to wild-type cells, but invasion was enhanced, indicating that deletion of occludin allowed larger numbers of bacteria to pass the tight junctions and to reach basal membranes to target the fibronectin receptor followed by cell entry. Finally, we discovered that purified C. jejuni HtrA cleaves recombinant occludin in vitro to release a 37 kDa carboxy-terminal fragment. The same cleavage fragment was observed in Western blots upon infection of polarized Caco-2 cells with wild-type C. jejuni, but not with isogenic Delta htrA mutants. HtrA cleavage was mapped to the second extracellular loop of occludin, and a putative cleavage site was identified. In conclusion, HtrA functions as a secreted protease targeting the tight junctions, which enables the bacteria by cleaving occludin and subcellular redistribution of other tight junction proteins to transmigrate using a paracellular mechanism and subsequently invade epithelial cells.
CRIS-Team WoS Importer:2019-03-06

Campylobacter jejuni Serine Protease HtrA Cleaves the Tight Junction Component Claudin-8 - Sharafutdinov, Irshad; Soltan Esmaeili, Delara; Harrer, Aileen; Tegtmeyer, Nicole; Sticht, Heinrich; Backert, Steffen (Frontiers in Cellular and Infection Microbiology, 2020)
Campylobacter jejuni express the high temperature requirement protein A (HtrA), a secreted serine protease, which is implicated in virulence properties of the pathogen. Previous studies have shown that C. jejuni HtrA can cleave the epithelial transmembrane proteins occludin and E-cadherin in the tight and adherens junctions, respectively. In the present report, we studied the interaction of HtrA with another human tight junction protein, claudin-8. Confocal immunofluorescence experiments have shown that C. jejuni infection of the intestinal polarized epithelial cells in vitro leads to a relocation of claudin-8. Wild-type C. jejuni induced the downregulation of claudin-8 signals in the tight junctions and an accumulation of claudin-8 agglomerates in the cytoplasm, which were not seen during infection with isogenic Delta htrA knockout deletion or protease-inactive S197A point mutants. Western blotting of protein samples from infected vs. uninfected cells revealed that an 18-kDa carboxy-terminal fragment is cleaved-off from the 26-kDa full-length claudin-8 protein, but not during infection with the isogenic Delta htrA mutant. These results were confirmed by in vitro cleavage assays using the purified recombinant C. jejuni HtrA and human claudin-8 proteins. Recombinant HtrA cleaved purified claudin-8 in vitro giving rise to the same 18-kDa sized carboxy-terminal cleavage product. Mapping studies revealed that HtrA cleavage occurs in the first extracellular loop of claudin-8. Three-dimensional modeling of the claudin-8 structure identified an exposed HtrA cleavage site between the amino acids alanine 58 and asparagine 59, which is in well agreement with the mapping studies. Taken together, HtrA operates as a secreted virulence factor targeting multiple proteins both in the tight and adherens junctions. This strategy may help the bacteria to open the cell-to-cell junctions, and to transmigrate across the intestinal epithelium by a paracellular mechanism and establish an acute infection.
CRIS-Team WoS Importer:2021-01-08

Can checkpoint inhibitor therapy improve response to chemotherapy? - Boßerhoff, Anja Katrin; Schuler, Gerold; Heinzerling, Lucie; Schilling, Bastian; Haferrkamp, Sebastian; Kirchberger, MC (2017)
EVALuna2:4767

Can checkpoint inhibitor therapy improve response to chemotherapy? - Kirchberger, Michael Constantin; Schilling, Bastian; Haferkamp, Sebastian; Boßerhoff, Anja Katrin; Schuler, Gerold; Heinzerling, Lucie (Journal of Cancer Research and Clinical Oncology, 2018)
EVALuna2:34410

Cardiac outflow tract development relies on the complex function of Sox4 and Sox11 in multiple cell types - Paul, Mandy; Harvey, Richard P.; Wegner, Michael; Sock, Elisabeth (Cellular and Molecular Life Sciences, 2014)
Congenital heart defects represent the most common human birth defects and are often life-threatening. Frequently, they are caused by abnormalities of the outflow tract whose formation results from coordinated development of cells from mesodermal and neural crest origin and depends on the activity of many different transcription factors. However, place, time, and mode of action have only been analyzed for a few of them. Here we assess the contribution of the closely related high-mobility-group transcription factors Sox4 and Sox11 to outflow tract development and determine their function. Using cell-type-specific deletion in the mouse, we show that Sox11 is required for proper development in both mesodermal cells and neural crest cells. Deletion in either mesoderm or neural crest, or both, leads to outflow tract defects ranging from double outlet right ventricle to common arterial trunk. Sox4 supports Sox11 in its function, but has additional roles with relevance for outflow tract formation in other cell types. The two Sox proteins are dispensable during early phases of cardiac neural crest development including neural tube emigration, proliferation, and migration through the pharyngeal arches. They become essential after arrival of the neural crest cells in the outflow tract for their proper differentiation and interaction with each other as well as with the environment through regulation of cytoskeletal, cell adhesion, and extracellular matrix molecules. Our results demonstrate that Sox4 and Sox11 have multiple functions in several cell types during outflow tract formation and may thus help to understand the basis of congenital heart defects in humans.
EVALuna2:4968

Casein kinase 2-dependent serine phosphorylation of MuSK regulates acetylcholine receptor aggregation at the neuromuscular junction. - Cheusova, Tatiana; Khan, Muhammad A.; Schubert, Steffen; Gavin, Anne-Claude; Buchou, Thierry; Jacob, Germaine; Sticht, Heinrich; Allende, Jorge; Boldyreff, Brigitte; Brenner, Hans Rudolf; Hashemolhosseini, Said (Genes & Development, 2006)
The release of Agrin by motoneurons activates the muscle-specific receptor tyrosine kinase (MuSK) as the main organizer of subsynaptic specializations at the neuromuscular junction. MuSK downstream signaling is largely undefined. Here we show that protein kinase CK2 interacts and colocalizes with MuSK at post-synaptic specializations. We observed CK2-mediated phosphorylation of serine residues within the kinase insert (KI) of MuSK. Inhibition or knockdown of CK2, or exchange of phosphorylatable serines by alanines within the KI of MuSK, impaired acetylcholine receptor (AChR) clustering, whereas their substitution by residues that imitate constitutive phosphorylation led to aggregation of AChRs even in the presence of CK2 inhibitors. Impairment of AChR cluster formation after replacement of MuSK KI with KIs of other receptor tyrosine kinases correlates with potential CK2-dependent serine phosphorylation within KIs. MuSK activity was unchanged but AChR stability decreased in the presence of CK2 inhibitors. Muscle-specific CK2β knockout mice develop a myasthenic phenotype due to impaired muscle endplate structure and function. This is the first description of a regulatory cross-talk between MuSK and CK2 and of a role for the KI of the receptor tyrosine kinase MuSK for the development of subsynaptic specializations. © 2006 by Cold Spring Harbor Laboratory Press.
UnivIS-Import:2015-03-09:Pub.2006.med.IB.LPCIPDBI.casein
Keywords: Casein kinase; CK2; MuSk; Neuromuscular junction; Skeletal muscle; Synapse

CD83 acts as immediate early response gene in activated macrophages and exhibits specific intracellular trafficking properties - Langguth, Pia; Peckert, Katrin; Beck, Philipp; Kuhnt, Christine; Draßner, Christina; Deinzer, Andrea; Steinkasserer, Alexander; Wild, Andreas (Biochemical and Biophysical Research Communications, 2023)
Macrophages (MΦ) are remarkably plastic cells, which assume phenotypes in every shade between a pro-inflammatory classical activation, and anti-inflammatory or resolving activation. Therefore, elucidation of mechanisms involved in shaping MΦ plasticity and function is key to understand their role during immunological balance. The immune-modulating CD83 molecule is expressed on activated immune cells and various tissue resident MΦ, rendering it an interesting candidate for affecting MΦ biology. However, in-depth analyses of the precise kinetics and trafficking of CD83 within pro-inflammatory, LPS activated bone-marrow-derived MΦ have not been performed. In this study, we show that activation with LPS leads to a very fast and strong, but transient increase of CD83 expression on these cells. Its expression peaks within 2 h of stimulation and is thereby faster than the early activation antigen CD69. To trace the CD83 trafficking through MΦs, we employed multiple inhibitors, thereby revealing a de novo synthesis and transport of the protein to the cell surface followed by lysosomal degradation, all within 6 h. Moreover, we found a similar expression kinetic and trafficking in human monocyte derived MΦ. This places CD83 at a very early point of MΦ activation suggesting an important role in decisions regarding the subsequent cellular fate.
CRIS-Team Scopus Importer:2023-02-10
Keywords: CD83; expression; intracellular trafficking; lipopolysaccharide; macrophages

CD83 and GRASP55 interact in human dendritic cells - Stein, Marcello F.; Blume, Katja; Heilingloh, Christiane; Kummer, Mirko; Biesinger, Brigitte; Sticht, Heinrich; Steinkasserer, Alexander (Biochemical and Biophysical Research Communications, 2015)
CD83 is one of the best known surface markers for mature human dendritic cells (DCs). The full-length 45 kDa type-I membrane-bound form (mbCD83) is strongly glycosylated upon DCs maturation. As co-stimulatory properties of CD83 are attributed to mbCD83 surface expression is required for efficient T-cell stimulation by mature DCs. By yeast two-hybrid screening, we were able to identify GRASP55 as interaction partner of CD83. DCs maturation induces endogenous CD83 protein expression with simultaneous regulation of CD83 glycosylation, interaction and co-localization with GRASP55 and CD83 surface exposure. GRASP55 is especially known for its role in maintaining Golgi architecture, but also plays a role in Golgi transport of specific cargo proteins bearing a C-terminal valine residue. Here we additionally demonstrate that binding of CD83 and GRASP55 rely on the C-terminal TELV-motif of CD83. Mutation of this TELV-motif not only disrupted binding to GRASP55, but also altered the glycosylation pattern of CD83 and reduced its membrane expression. Here we show for the first time that GRASP55 interacts with CD83 shortly after induction of DC maturation and that this interaction plays a role in CD83 glycosylation as well as in surface expression of CD83 on DCs.
EVALuna2:8259

CD83 expression is essential for Treg cell differentiation and stability - Döbbeler, Marina; Koenig, Christina; Krzyzak, Lena; Seitz, Christine; Wild, Andreas; Ulas, Thomas; Bassler, Kevin; Kopelyanskiy, Dmitry; Butterhof, Alina; Kuhnt, Christine; Kreiser, Simon; Stich, Lena; et al. (JCI Insight, 2018)
Foxp3-positive regulatory T cells (Tregs) are crucial for the maintenance of immune homeostasis and keep immune responses in check. Upon activation, Tregs are transferred into an effector state expressing transcripts essential for their suppressive activity, migration, and survival. However, it is not completely understood how different intrinsic and environmental factors control differentiation. Here, we present for the first time to our knowledge data suggesting that Treg-intrinsic expression of CD83 is essential for Treg differentiation upon activation. Interestingly, mice with Treg-intrinsic CD83 deficiency are characterized by a proinflammatory phenotype. Furthermore, the loss of CD83 expression by Tregs leads to the downregulation of Treg-specific differentiation markers and the induction of an inflammatory profile. In addition, Treg-specific conditional knockout mice showed aggravated autoimmunity and an impaired resolution of inflammation. Altogether, our results show that CD83 expression in Tregs is an essential factor for the development and function of effector Tregs upon activation. Since Tregs play a crucial role in the maintenance of immune tolerance and thus prevention of autoimmune disorders, our findings are also clinically relevant.
EVALuna2:36212

CD83 orchestrates immunity toward self and non-self in dendritic cells - Wild, Andreas; Krzyzak, Lena; Peckert, Katrin; Stich, Lena; Kuhnt, Christine; Butterhof, Alina; Seitz, Christine; Mattner, Jochen; Grner, Niklas; Gänsbauer, Maximilian; Purtak, Martin; Soulat, Didier; et al. (JCI Insight, 2019)
Dendritic cells (DCs) are crucial to balance protective immunity and autoimmune inflammatory processes. Expression of CD83 is a well-established marker for mature DCs, although its physiological role is still not completely understood. Using a DC-specific CD83-conditional KO (CD83(Delta DC)) mouse, we provide new insights into the function of CD83 within this cell type. Interestingly, CD83-deficient DCs produced drastically increased IL-2 levels and displayed higher expression of the costimulatory molecules CD25 and OX40L, which causes superior induction of antigen-specific T cell responses and compromises Treg suppressive functions. This also directly translates into accelerated immune responses in vivo. Upon Salmonella typhimurium and Listeria monocytogenes infection, CD83(Delta DC) mice cleared both pathogens more efficiently, and CD83-deficient DCs expressed increased IL-12 levels after bacterial encounter. Using the experimental autoimmune encephalomyelitis model, autoimmune inflammation was dramatically aggravated in CD83(Delta DC) mice while resolution of inflammation was strongly reduced. This phenotype was associated with increased cell influx into the CNS accompanied by elevated Th17 cell numbers. Concomitantly, CD83(Delta DC) mice had reduced Treg numbers in peripheral lymphoid organs. In summary, we show that CD83 ablation on DCs results in enhanced immune responses by dysregulating tolerance mechanisms and thereby impairing resolution of inflammation, which also demonstrates high clinical relevance.
CRIS-Team WoS Importer:2019-11-01

Cellular and extracellular proteome of the animal pathogen corynebacterium silvaticum, a close relative of zoonotic corynebacterium ulcerans and corynebacterium pseudotuberculosis - Möller, Jens; Schorlemmer, Svenja; Hofmann, Jörg; Burkovski, Andreas (Proteomes, 2020)
Corynebacterium silvaticum is a newly described animal pathogen, closely related to the emerging human pathogen Corynebacterium ulcerans and Corynebacterium pseudotuberculosis, a major pathogen of small ruminants. In this study, proteins of a whole cell and a shaving fraction and the exoproteome of C. silvaticum strain W25 were analyzed as a first proteome study of this species. In total, 1305 proteins were identified out of 2013 proteins encoded by the W25 genome sequence and number of putative virulence factors were detected already under standard growth conditions including phospholipase D and sialidase. An up to now uncharacterized trypsin-like protease is by far the most secreted protein in this species, indicating a putative role in pathogenicity. Furthermore, the proteome analyses carried out in this study support the recently published taxonomical delineation of C. silvaticum from the closely related zoonotic Corynebacterium species.
CRIS-Team Scopus Importer:2020-09-11
Keywords: Exoproteome; LC-MS/MS; Mass spectrometry; Necrotizing lymphadenitis; Secretome; Trypsin-like serine protease; Zoonosis

Cellular identity through the lens of direct lineage reprogramming - Falk, Sven; Han, Dandan; Karow, Marisa (Current Opinion in Genetics & Development, 2021)
Direct lineage reprogramming challenges our traditional view on basic aspects of cellular identity, and in particular on processes crucial for identity acquisition. This is partly because in direct lineage reprogramming but not during natural differentiation processes changing cellular identity can occur in the absence of mitosis. Only recently, technologies emerged to deconstruct the cellular and molecular processes governing the transitory states a cell passes through on the journey from its original identity to the new target cell fate. Here we discuss arising concepts on the nature of these transitory states and the challenges and decisions cells must conquer to reach their new cellular identity.
CRIS-Team Scopus Importer:2021-08-20

Centrosomal microtubule nucleation regulates radial migration of projection neurons independently of polarization in the developing brain - Vinopal, Stanislav; Dupraz, Sebastian; Alfadil, Eissa; Pietralla, Thorben; Bendre, Shweta; Stiess, Michael; Falk, Sven; Ortega, German Camargo; Maghelli, Nicola; Tolic, Iva M.; Smejkal, Jiri; Goetz, Magdalena; et al. (Neuron, 2023)
Cortical projection neurons polarize and form an axon while migrating radially. Even though these dynamic processes are closely interwoven, they are regulated separately-the neurons terminate their migration when reaching their destination, the cortical plate, but continue to grow their axons. Here, we show that in rodents, the centrosome distinguishes these processes. Newly developed molecular tools modulating centrosomal microtubule nucleation combined with in vivo imaging uncovered that dysregulation of centro-somal microtubule nucleation abrogated radial migration without affecting axon formation. Tightly regu-lated centrosomal microtubule nucleation was required for periodic formation of the cytoplasmic dilation at the leading process, which is essential for radial migration. The microtubule nucleating factor g-tubulin decreased at neuronal centrosomes during the migratory phase. As distinct microtubule networks drive neuronal polarization and radial migration, this provides insight into how neuronal migratory defects occur without largely affecting axonal tracts in human developmental cortical dysgeneses, caused by mutations in g-tubulin.
CRIS-Team WoS Importer:2023-05-26

Cereblon is expressed in the retina and binds to voltage-gated chloride channels. - Hohberger, Bettina; Enz, Ralf (FEBS letters, 2009)
UnivIS-Import:2018-09-11:Pub.2009.med.IB.profes_1.cerebl
Keywords: Cereblon; CIC-1; CIC-2; CRBN; Protein interaction; Retina

Challenges for the implementation of next generation sequencing-based expanded carrier screening: Lessons learned from the ciliopathies - Vintschger, Ella; Kraemer, Dennis; Joset, Pascal; Horn, Anselm; Rauch, Anita; Sticht, Heinrich; Bachmann-Gagescu, Ruxandra (European Journal of Human Genetics, 2022)
Next generation sequencing (NGS) can detect carrier status for rare recessive disorders, informing couples about their reproductive risk. The recent ACMG recommendations support offering NGS-based carrier screening (NGS-CS) in an ethnic and population-neutral manner for all genes that have a carrier frequency > 1/200 (based on GnomAD). To evaluate current challenges for NGS-CS, we focused on the ciliopathies, a well-studied group of rare recessive disorders. We analyzed 118 ciliopathy genes by whole exome sequencing in similar to 400 healthy local individuals and similar to 1000 individuals from the UK1958-birth cohort. We found 20% of healthy individuals (1% of couples) to be carriers of reportable variants in a ciliopathy gene, while 50% (4% of couples) carry variants of uncertain significance (VUS). This large proportion of VUS is partly explained by the limited utility of the ACMG/AMP variant-interpretation criteria in healthy individuals, where phenotypic match or segregation criteria cannot be used. Most missense variants are thus classified as VUS and not reported, which reduces the negative predictive value of the screening test. We show how gene-specific variation patterns and structural protein information can help prioritize variants most likely to be disease-causing, for (future) functional assays. Even when considering only strictly pathogenic variants, the observed carrier frequency is substantially higher than expected based on estimated disease prevalence, challenging the 1/200 carrier frequency cut-off proposed for choice of genes to screen. Given the challenges linked to variant interpretation in healthy individuals and the uncertainties about true carrier frequencies, genetic counseling must clearly disclose these limitations of NGS-CS.
CRIS-Team WoS Importer:2023-02-03

Channel Estimation for Diffusive Molecular Communications - Jamali Kooshkghazi, Vahid; Ahmadzadeh, Arman; Jardin, Christophe; Sticht, Heinrich; Schober, Robert (IEEE Transactions on Communications, 2016)
In molecular communication (MC) systems, the expected number of molecules observed at the receiver over time after the instantaneous release of molecules by the transmitter is referred to as the channel impulse response (CIR). Knowledge of the CIR is needed for the design of detection and equalization schemes. In this paper, we present a training-based CIR estimation framework for MC systems, which aims at estimating the CIR based on the observed number of molecules at the receiver due to emission of a sequence of known numbers of molecules by the transmitter. Thereby, we distinguish two scenarios depending on whether or not statistical channel knowledge is available. In particular, we derive maximum likelihood and least sum of square errors estimators, which do not require any knowledge of the channel statistics. For the case, when statistical channel knowledge is available, the corresponding maximum a posteriori and linear minimum mean square error estimators are provided. As performance bound, we derive the classical Cramer Rao (CR) lower bound, valid for any unbiased estimator, which does not exploit statistical channel knowledge, and the Bayesian CR lower bound, valid for any unbiased estimator, which exploits statistical channel knowledge. Finally, we propose the optimal and suboptimal training sequence designs for the considered MC system. Simulation results confirm the analysis and compare the performance of the proposed estimation techniques with the respective CR lower bounds.<br
Keywords: Channel estimation; Receivers; Transmitters; Channel models; Maximum likelihood estimation; Training

Channel estimation techniques for diffusion-based molecular communications - Jamali Kooshkghazi, Vahid; Ahmadzadeh, Arman; Jardin, Christophe; Sticht, Heinrich; Schober, Robert (2016 IEEE International Conference on Communications (ICC), 2016)
In molecular communication (MC) systems, the expected number of molecules observed at the receiver over time after the instantaneous release of molecules by the transmitter is referred to as the channel impulse response (CIR). Knowledge of the CIR is needed for the design of detection and equalization schemes. In this paper, we present a training-based CIR estimation framework for MC systems which aims at estimating the CIR based on the observed number of molecules at the receiver due to emission of a sequence of known numbers of molecules by the transmitter. In particular, we derive maximum likelihood (ML) and least sum of square errors (LSSE) estimators. We also study the Cramer Rao (CR) lower bound and training sequence design for the considered system. Simulation results confirm the analysis and compare the performance of the proposed estimation techniques with the CR lower bound.<br
Keywords: Receivers; Transmitters; Channel estimation; Channel models; Maximum likelihood estimation; Training

Characterization of a discontinuous neutralizing epitope on glycoprotein B of human cytomegalovirus - Spindler, Nadja; Ruecker, Pia; Pötzsch, Sonja; Diestel, Uschi; Sticht, Heinrich; Martin-Parras, Luis; Winkler, Thomas; Mach, Michael (Journal of Virology, 2013)
Human cytomegalovirus (HCMV) is a ubiquitously distributed pathogen that causes severe disease in immunosuppressed patients and newborn infants infected in utero. The viral envelope glycoprotein B (gB) is an attractive molecule for active vaccination and passive immunoprophylaxis and therapy. Using human monoclonal antibodies (MAbs), we have recently identified antigenic region 4 (AD-4) on gB as an important target for neutralizing antibodies. AD-4 is formed by a discontinuous sequence comprising amino acids 121 to 132 and 344 to 438 of gB of HCMV strain AD169. To map epitopes for human antibodies on this protein domain, we used a three-dimensional (3D) model of HCMV gB to identify surface-exposed amino acids on AD-4 and selected juxtaposed residues for alanine scans. A tyrosine (Y) at position 364 and a lysine (K) at position 379 (the YK epitope), which are immediate neighbors on the AD-4 surface, were found to be essential for binding of the human MAbs. Recognition of AD-4 by sera from HCMV-infected individuals also was largely dependent on these two residues, indicating a general importance for the antibody response against AD-4. A panel of AD-4 recombinant viruses harboring mutations at the crucial antibody binding sites was generated. The viruses showed significantly reduced susceptibility to neutralization by AD-4-specific MAbs or polyclonal AD-4-specific antibodies, indicating that the YK epitope is dominant for the AD-4-specific neutralizing antibody response during infection. To our knowledge, this is the first molecular identification of a functional discontinuous epitope on HCMV gB. Induction of antibodies specific for this epitope may be a desirable goal following vaccination with gB.
EVALuna2:8189

Characterization of a single-chain variable fragment recognizing a linear epitope of a?: a biotechnical tool for studies on Alzheimer's disease? - Dornieden, Silke; Mueller-Schiffmann, Andreas; Sticht, Heinrich; Jiang, Nan; Cinar, Yeliz; Woerdehoff, Michael; Korth, Carsten; Funke, Susanne Aileen; Willbold, Dieter (PLoS ONE, 2013)
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with devastating effects. Currently, therapeutic options are limited to symptomatic treatment. For more than a decade, research focused on immunotherapy for the causal treatment of AD. However, clinical trials with active immunization using A? encountered severe complications, for example meningoencephalitis. Consequently, attention focused on passive immunization using antibodies. As an alternative to large immunoglobulins (IgGs), A? binding single-chain variable fragments (scFvs) were used for diagnostic and therapeutic research approaches. scFvs can be expressed in E. coli and may provide improved pharmacokinetic properties like increased blood-brain barrier permeability or reduced side-effects in vivo. In this study, we constructed an scFv from an A? binding IgG, designated IC16, which binds the N-terminal region of A? (A?(1-8)). scFv-IC16 was expressed in E. coli, purified and characterized with respect to its interaction with different A? species and its influence on A? fibril formation. We were able to show that scFv-IC16 strongly influenced the aggregation behavior of A? and could be applied as an A? detection probe for plaque staining in the brains of transgenic AD model mice. The results indicate potential for therapy and diagnosis of AD.
EVALuna2:26279

Characterization of Glomerular Sox9+ Cells in Anti-Glomerular Basement Membrane Nephritis in the Rat - Prochnicki, Ania; Amann, Kerstin Ute; Wegner, Michael; Sock, Elisabeth; Pfister, Eva; Shankland, Stuart; Pippin, Jeffrey; Daniel, Christoph (American Journal of Pathology, 2018)
Mechanisms of glomerular crescent formation and podocyte repair processes are still unclear. Therefore, we investigated the expression of the transcription factor Sox9 as a potential marker of a subpopulation of parietal epithelial cells (PECs) with potential regenerative properties. Glomerular Sox9 expression was characterized in detail in a rat anti-glomerular basement membrane (GBM) nephritis model using immunofluorescence and confocal laser scanning microscopy. In healthy kidneys Sox9 is expressed in a subpopulation of PECs restricted to approximately 20% to 50% of PEC nuclei and was highly conserved in all investigated species. During rat anti-GBM nephritis the number of glomerular Sox9+ cells increased and was associated with proliferation activity. In nephritic glomeruli Sox9 expression was not restricted to Bowman's capsule lining but was also found on cells of the glomerular tuft. Nearly all Sox9+ cells also expressed the PEC marker Pax8, whereas endothelial cells, mesangial cells, macrophages, and T lymphocytes lacked Sox9 expression. At the margins of crescents Sox9+/Pax8+ cells additionally expressed podocyte markers. In contrast, in sclerotic lesions a minority of Sox9+/Pax8+ cells expressed the myofibroblast marker α-smooth muscle actin. In glomerular Sox9+ cells Jagged 1 was up-regulated. During anti-GBM nephritis Sox9+ PECs proliferate and migrate onto the glomerular tuft. Future studies are needed to confirm the origin of Sox9+ cells from PECs and differentiation in both podocytes and/or myofibroblasts.
EVALuna2:35393

Characterization of glycolysis-related gene expression in malignant melanoma - Koch, Andreas; Ebert, Eva Vanessa; Seitz, Tatjana; Dietrich, Peter; Berneburg, Mark; Boßerhoff, Anja Katrin; Hellerbrand, Claus (Pathology Research and Practice, 2020)
Malignant melanoma exhibits a distinct metabolic phenotype with high glycolytic activity. Previously, we have shown that glucose transporter isoform 1 (GLUT1) favors growth and metastasis of malignant melanoma. In this study, we investigated the expression of GLUT1 and the further glycolysis-related genes hexokinase 1 and 2 (HK1, HK2), lactate dehydrogenase A (LDH-A) and monocarboxylate transporters 1 and 4 (MCT1, MCT4) in eleven human melanoma cell lines under normoxic and hypoxic conditions. Furthermore, a set of 25 human malignant melanoma tissue samples was analyzed. Under hypoxic conditions, we could observe a significant upregulation of hypoxia-inducible factor 1 alpha (HIF-1a) target genes GLUT1, HK2 and LDH-A, but not MCT4. While under normoxic conditions the expression of glycolysis-related genes showed no correlation with origin or BRAF mutation status, GLUT1 expression was significantly elevated in metastatic and BRAF-V600E mutated melanoma cell lines under hypoxic conditions. Furthermore, GLUT1 expression in human melanoma tissue samples correlated significantly with HK1, LDH-A and MCT1 expression, confirming a glycolytic phenotype. Notably, Cyclin D1 expression, which is used as a prognostic marker for the outcome of melanoma patients, as it is associated with proliferation and invasiveness of melanoma, significantly correlated with GLUT1, HK1, LDH-A and MCT1 expression. In summary, our findings provide further evidence that enhanced glycolytic activity in melanoma favors disease progression and is an attractive therapeutic target for this highly aggressive tumor.
CRIS-Team Scopus Importer:2019-12-13
Keywords: Cyclin D1; GLUT1; Glycolysis; HK1; HK2; LDH-A; MCT1; MCT4; Melanoma

Characterization of recombinant human cytomegaloviruses encoding IE1 mutants L174P and 1-382 reveals that viral targeting of PML bodies perturbs both intrinsic and innate immune responses - Scherer, Myriam; Otto, Victoria; Stump, Joachim; Klingl, Stefan; Müller, Regina; Reuter, Nina; Muller, Yves; Sticht, Heinrich; Stamminger, Thomas (Journal of Virology, 2015)
PML is the organizer of cellular structures termed nuclear domain 10 (ND10) or PML-nuclear bodies (PML-NBs) that act as key mediators of intrinsic immunity against human cytomegalovirus (HCMV) and other viruses. The antiviral function of ND10 is antagonized by viral regulatory proteins such as the immediate early protein IE1 of HCMV. IE1 interacts with PML through its globular core domain (IE1) and induces ND10 disruption in order to initiate lytic HCMV infection. Here, we investigate the consequences of a point mutation (L174P) in IE1CORE, which was shown to abrogate the interaction with PML, for lytic HCMV infection. We found that a recombinant HCMV encoding IE1-L174P displays a severe growth defect similar to that of an IE1 deletion virus. Bioinformatic modeling based on the crystal structure of IE1 suggested that insertion of proline into the highly alpha-helical domain severely affects its structural integrity. Consistently, L174P mutation abrogates the functionality of IE1 and results in degradation of the IE1 protein during infection. In addition, our data provide evidence that IE1 as expressed by a recombinant HCMV encoding IE1 1-382 not only is required to antagonize PML-mediated intrinsic immunity but also affects a recently described function of PML in innate immune signaling. We demonstrate a coregulatory role of PML in type I and type II interferon-induced gene expression and provide evidence that upregulation of interferon-induced genes is inhibited by IE1. In conclusion, our data suggest that targeting PML by viral regulatory proteins represents a strategy to antagonize both intrinsic and innate immune mechanisms.
EVALuna2:8299

Characterization of SARS-CoV-2 Escape Mutants to a Pair of Neutralizing Antibodies Targeting the RBD and the NTD - Peter, Antonia Sophia; Grüner, Eva; Socher, Eileen; Fraedrich, Kirsten; Richel, Elie; Müller-Schmucker, Sandra; Cordsmeier, Arne; Enßer, Armin; Sticht, Heinrich; Überla, Klaus (International Journal of Molecular Sciences, 2022)
Mutations in the spike protein of SARS-CoV-2 can lead to evasion from neutralizing antibodies and affect the efficacy of passive and active immunization strategies. Immunization of mice harboring an entire set of human immunoglobulin variable region gene segments allowed to identify nine neutralizing monoclonal antibodies, which either belong to a cluster of clonally related RBD or NTD binding antibodies. To better understand the genetic barrier to emergence of SARS-CoV-2 variants resistant to these antibodies, escape mutants were selected in cell culture to one antibody from each cluster and a combination of the two antibodies. Three independently derived escape mutants to the RBD antibody harbored mutations in the RBD at the position T478 or S477. These mutations impaired the binding of the RBD antibodies to the spike protein and conferred resistance in a pseudotype neutralization assay. Although the binding of the NTD cluster antibodies were not affected by the RBD mutations, the RBD mutations also reduced the neutralization efficacy of the NTD cluster antibodies. The mutations found in the escape variants to the NTD antibody conferred resistance to the NTD, but not to the RBD cluster antibodies. A variant resistant to both antibodies was more difficult to select and only emerged after longer passages and higher inoculation volumes. VOC carrying the same mutations as the ones identified in the escape variants were also resistant to neutralization. This study further underlines the rapid emergence of escape mutants to neutralizing monoclonal antibodies in cell culture and indicates the need for thorough investigation of escape mutations to select the most potent combination of monoclonal antibodies for clinical use.
CRIS-Team WoS Importer:2022-08-26

Characterization of the Methylthioadenosine Phosphorylase Polymorphism rs7023954 - Incidence and Effects on Enzymatic Function in Malignant Melanoma - Limm, Katharina; Dettmer, Katja; Reinders, Joerg; Oefner, Peter J.; Boßerhoff, Anja Katrin (PLoS ONE, 2016)
Deficiency of methylthioadenosine phosphorylase (MTAP) supports melanoma development and progression through accumulation of its substrate 5'-methylthioadenosine (MTA), which leads amongst others to a constitutive inhibition of protein arginine methyltransferases (PRMTs) and activation of the transcription factor AP-1 via the receptor ADORA2B. Genetic association studies have also suggested that genetic polymorphism in MTAP may modulate the risk of melanoma. Here, we investigated the only globally common non-synonymous single nucleotide polymorphism (SNP) reported to date for MTAP. The SNP rs7023954 is located in exon 3 (c.166G>A), and leads to the conservative substitution of one branched-chain amino acid residue (valine) for another (isoleucine) at position 56 (p.Val56Ile). Whereas genotype frequencies in normal and primary melanoma tissues or cell lines were in Hardy-Weinberg equilibrium based on cDNA amplicon sequencing, a marked (P = 0.00019) deviation was observed in metastatic melanoma tissues and cell lines due to a deficit of heterozygotes. Enzyme assays conducted on the co-dominantly expressed alleles revealed no difference in the conversion rate of MTA to adenine and 5-methylthioribose-1-phosphate, indicating that this known enzymatic activity does not modulate the tumor suppressive function of MTAP.
EVALuna2:4733

CHARACTERIZATION OF THE SPYTAG - SPY-CATCHER INTERACTION - Ludwig, Jonas; Ulm, Nadine; Pröschel, Marlene; Sticht, Heinrich; Sonnewald, Uwe; Eichler, Jutta (Journal of Peptide Science, 2016)

Characterization of two mutations in the SPTLC1 subunit of serine palmitoyltransferase associated with hereditary sensory and autonomic neuropathy type I - Rotthier, Annelies; Penno, Anke; Rautenstrauss, Bernd; Auer-Grumbach, Michaela; Stettner, Georg M.; Asselbergh, Bob; Van Hoof, Kim; Sticht, Heinrich; Levy, Nicolas; Timmerman, Vincent; Hornemann, Thorsten; Janssens, Katrien (Human Mutation, 2011)
Hereditary sensory and autonomic neuropathy type I (HSAN-I) is an axonal peripheral neuropathy leading to progressive distal sensory loss and severe ulcerations. Mutations in SPTLC1 and SPTLC2, encoding the two subunits of serine palmitoyltransferase (SPT), the enzyme catalyzing the first and rate-limiting step in the de novo synthesis of sphingolipids, have been reported to cause HSAN-I. Here, we demonstrate that the SPTLC1 mutations p.S331F and p.A352V result in a reduction of SPT activity in vitro and are associated with increased levels of the deoxysphingoid bases 1-deoxy-sphinganine and 1-deoxymethyl-sphinganine in patients' plasma samples. Stably expressing p.S331F-SPTLC1 HEK293T cell lines likewise show accumulation of deoxysphingoid bases, but this accumulation is not observed in HEK293T cells overexpressing p.A352V-SPTLC1. These results confirm that the increased formation of deoxysphingoid bases is a key feature for HSAN-I as it is associated with all pathogenic SPTLC1 and SPTLC2 mutations reported so far, but also warrant for caution in the interpretation of in vitro data.
EVALuna2:26264

Characterizing the interaction between the htlv-1 transactivator tax-1 with transcription elongation factor ell2 and its impact on viral transactivation - Kohrt, Stephan; Strobel, Sarah; Mann, Melanie; Sticht, Heinrich; Fleckenstein, Bernhard; Thoma-Kreß, Andrea (International Journal of Molecular Sciences, 2021)
The human T-cell leukemia virus type 1 (HTLV-1)-encoded transactivator and oncoprotein Tax-1 is essential for HTLV-1 replication. We recently found that Tax-1 interacts with transcription elongation factor for RNA polymerase II 2, ELL2, which enhances Tax-1-mediated transactivation of the HTLV-1 promotor. Here, we characterize the Tax-1:ELL2 interaction and its impact on viral transactivation by confocal imaging, co-immunoprecipitation, and luciferase assays. We found that Tax-1 and ELL2 not only co-precipitate, but also co-localize in dot-like structures in the nucleus. Tax-1:ELL2 complex formation occurred independently of Tax-1 point mutations, which are crucial for post translational modifications (PTMs) of Tax-1, suggesting that these PTMs are irrelevant for Tax-1:ELL2 interaction. In contrast, Tax-1 deletion mutants lacking either N-terminal (aa 1–37) or C-terminal regions (aa 150–353) of Tax-1 were impaired in interacting with ELL2. Contrary to Tax-1, the related, non-oncogenic Tax-2B from HTLV-2B did not interact with ELL2. Finally, we found that ELL2-R1 (aa 1–353), which carries an RNA polymerase II binding domain, and ELL2-R3 (aa 515–640) are sufficient to interact with Tax-1; however, only ELL2-truncations expressing R1 could enhance Tax-1-mediated transactivation of the HTLV-1 promoter. Together, this study identifies domains in Tax-1 and ELL2 being required for Tax-1:ELL2 complex formation and for viral transactivation.
CRIS-Team Scopus Importer:2021-12-24
Keywords: ELL2; HTLV-1; Human T-cell leukemia virus type 1; Tax-1; Tax-2; Transcription elongation factor for RNA polymerase II; Viral oncoprotein; Viral transactivation

Chromatin remodeler Ep400 ensures oligodendrocyte survival and is required for myelination in the vertebrate central nervous system - Elsesser, Olga; Fröb, Franziska; Küspert, Melanie; Tamm, Ernst R.; Fujii, Toshihiro; Fukunaga, Rikiro; Wegner, Michael (Nucleic Acids Research, 2019)
Differentiating oligodendrocytes generate myelin to ensure rapid saltatory conduction in the vertebrate central nervous system. Although oligodendroglial differentiation and myelination are accompanied by dramatic chromatin reorganizations, previously studied chromatin remodelers had only limited direct effects on the process. To study the functional significance of chromatin changes for myelination and identify relevant remodelers, we deleted Ep400, the central ATP-hydrolyzing subunit of the TIP60/EP400 complex, at defined times of mouse oligodendrocyte development. Whereas Ep400-deficient oligodendrocyte precursors develop normally, terminal differentiation and myelination are dramatically impaired. Mechanistically, Ep400 interacts with transcription factor Sox10, binds to regulatory regions of the Myrf gene and is required to induce this central transcriptional regulator of the myelination program. In addition to reduced and aberrant myelin formation, oligodendrocytes exhibit increased DNA damage and apoptosis so that numbers never reach wildtype levels during the short lifespan of Ep400-deficient mice. Ep400 deletion in already mature oligodendrocytes remains phenotypically inapparent arguing that Ep400 is dispensable for myelin maintenance. Given its essential function in myelin formation, modulation of Ep400 activity may be beneficial in conditions such as multiple sclerosis where this process is compromised.
CRIS-Team Scopus Importer:2019-07-30

Chromatin remodelling factor Brg1 is required for Schwann cell differentiation and myelination. - Weider, Matthias; Küspert, Melanie; Bischof, Melanie; Müller, Jana; Hillgärtner, Simone; Wegner, Michael; et al. (Developmental Cell, 2012)
Schwann cells produce myelin sheaths and thereby permit rapid saltatory conductance in the vertebrate peripheral nervous system. Their stepwise differentiation from neural crest cells is driven by a defined set of transcription factors. How this is linked to chromatin changes is not well understood. Here we show that the glial transcription factor Sox10 functions in Schwann cells by recruiting Brg1-containing chromatin-remodeling complexes via Baf60a to regulatory regions of Oct6 and Krox20 genes. It thereby stimulates expression of these transcriptional regulators that then cooperate with Sox10 to convert immature into myelinating Schwann cells. The functional interaction between Sox10 and Brg1 is evident from gain- and loss-of-function studies, similar neuropathies in the corresponding mouse mutants, and an aggravated neuropathy in compound mutants. Our results demonstrate that the transcription factor-mediated recruitment of the chromatin-remodeling machinery to specific genomic loci is an essential driving force for Schwann cell differentiation and myelination. © 2012 Elsevier Inc.
UnivIS-Import:2015-03-09:Pub.2012.med.IB.LPCIPDBI.chroma

Chronicles of a switch hunt: gcm genes in development - Wegner, Michael; et al. (Trends in Genetics, 2001)
Co-conservation of sequence and function is an important principle during evolution. As a consequence, sequence-related genes often have similar functions in evolutionarily distant species. Enter the 'glial cells missing' (gcm) genes. They code for a small family of novel transcription factors that share DNA-binding properties and domain structure. However, no evolutionarily conserved function is apparent as yet. The prototypical gcm from Drosophila dominates nervous system development as a fate switch and master regulator of gliogenesis, whereas mammalian gcm genes have roles in placental morphogenesis and development of the parathyroid gland. Apparently, structure and function sometimes can go separate ways.
UnivIS-Import:2015-03-09:Pub.2001.med.IB.LPCIPDBI.chroni

Chronic Psychosocial Stress in Mice Is Associated With Increased Acid Sphingomyelinase Activity in Liver and Serum and With Hepatic C16:0-Ceramide Accumulation - Reichel, Martin; Rhein, Cosima; Hofmann, Lena M.; Monti, Juliana; Japtok, Lukasz; Langgartner, Dominik; Fuechsl, Andrea M.; Kleuser, Burkhard; Gulbins, Erich; Hellerbrand, Claus; Reber, Stefan O.; Kornhuber, Johannes (Frontiers in Psychiatry, 2018)
Chronic psychosocial stress adversely affects human morbidity and is a risk factor for inflammatory disorders, liver diseases, obesity, metabolic syndrome, and major depressive disorder (MDD). In recent studies, we found an association of MDD with an increase of acid sphingomyelinase (ASM) activity. Thus, we asked whether chronic psychosocial stress as a detrimental factor contributing to the emergence of MDD would also affect ASM activity and sphingolipid (SL) metabolism. To induce chronic psychosocial stress in male mice we employed the chronic subordinate colony housing (CSC) paradigm and compared them to non-stressed single housed control (SHC) mice. We determined Asm activity in liver and serum, hepatic SL concentrations as well as hepatic mRNA expression of genes involved in SL metabolism. We found that hepatic Asm activity was increased by 28% (P = 0.006) and secretory Asm activity by 47% (P = 0.002) in stressed mice. C16:0-Cer was increased by 40% (P = 0.008). Gene expression analysis further revealed an increased expression of tumor necrosis factor (TNF)-α (P = 0.009) and of several genes involved in SL metabolism (Cers5, P = 0.028; Cers6, P = 0.045; Gba, P = 0.049; Gba2, P = 0.030; Ormdl2, P = 0.034; Smpdl3B; P = 0.013). Our data thus provides first evidence that chronic psychosocial stress, at least in mice, induces alterations in SL metabolism, which in turn might be involved in mediating the adverse health effects of chronic psychosocial stress and peripheral changes occurring in mood disorders.
EVALuna2:35808

Circadian rhythm and day to day variability of serum potassium concentration: a pilot study - Schmidt, Stefan; Ditting, T.; Deutsch, Birgit; Schutte, R.; Friedrich, S.; Kistner, I.; Ott, Christian; Raff, U.; Veelken, Roland; Schmieder, Roland (Journal of Nephrology, 2015)
Hyperkalemia is a common and life-threatening complication frequently seen in patients with acute kidney injury, end-stage renal disease and chronic heart failure. Cardiac arrest and ventricular fibrillation are possible consequences. Biosensors are currently being developed to measure serum potassium under ambulatory conditions and trigger an alarm if the potassium concentration exceeds normal limits. Only few studies exist on the circadian rhythm of potassium; and its dependence on age and kidney function is less clear.Our observational monocentric exploratory study included 30 subjects of which 15 had impaired renal function (RF) (GFR <60 ml/min/1.73 m(2)). Subjects were further categorized into three age groups: 18-39 years (N normal RF = 5, N impaired RF = 4), 40-59 years (N normal RF = 5, N impaired RF = 6), 60-80 years (N normal RF = 5, N impaired RF = 5). Serum potassium levels were measured every 2 h during a 24 h period and repeated once after 2, 4, or 6 days.In the 15 subjects with normal RF, the lowest mean potassium level (3.96 ± 0.14 mmol/l) was observed at 9 p.m. and the greatest (4.23 ± 0.23 mmol/l) at 1 p.m. In patients with impaired RF the lowest mean potassium level (4.20 ± 0.32 mmol/l) was observed at 9 p.m. and the highest (4.57 ± 0.46 mmol/l) at 3 p.m. The range between the mean of minimum and maximum was greater in patients with impaired RF (0.71 ± 0.45 mmol/l) than in subjects with normal RF (0.53 ± 0.14 mmol/l) [p < 0.001]. No difference in the circadian rhythm was found between the first and second examination.Our results indicate that patients with normal and impaired RF have comparable circadian patterns of serum potassium concentrations, but higher fluctuations in patients with impaired RF. These results have clinical relevance for developing an automatic biosensor to measure the potassium concentration in blood under ambulatory conditions in patients at high risk for potassium fluctuations.
EVALuna2:3700

C-Jun drives melanoma progression in PTEN wild type melanoma cells - Kappelmann-Fenzl, Melanie; Gebhard, Claudia; Matthies, Alexander Oliver; Kuphal, Silke; Rehli, Michael; Boßerhoff, Anja Katrin (Cell Death & Disease, 2019)
Due to the critical impact of active AP-1 transcription factors in melanoma, it is important to define their target genes and to identify and ultimately inhibit oncogenic signals. Here we mapped the genome-wide occupancy of the AP-1 family member c-Jun in different melanoma cells and correlated AP-1 binding with transcriptome data to detect genes in melanoma regulated by c-Jun. Our analysis shows that c-Jun supports the malignant phenotype by deregulating genes in cancer-relevant signaling pathways, such as mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K) pathways. Moreover, we demonstrate that the importance of c-Jun depends on melanoma stage and mutation status of the tumor suppressor PTEN. Our study reveals that activation of c-Jun overrules the tumor suppressive effect of PTEN in early melanoma development. These findings help to understand the relevance of c-Jun within cancer pathways in different melanoma cell types, especially in relation to MAPK and PI3K pathways, which are commonly deregulated in melanomas. Consequently, targeting c-Jun in PTEN+ melanoma cells may represent a promising therapeutic strategy to inhibit survival of melanoma cells to prevent the development of a metastatic phenotype.
CRIS-Team Scopus Importer:2019-08-13

Clinical and molecular delineation of spondylocostal dysostosis type 3 - Schuhmann, Sarah; Koller, Heiko; Sticht, Heinrich; Kraus, Cornelia; Krumbiegel, Mandy; Uebe, Steffen; Ekici, Arif Bülent; Reis, André; Thiel, Christian (Clinical Genetics, 2021)
CRIS-Team Scopus Importer:2021-03-26

Clinical relevance of systematic phenotyping and exome sequencing in patients with short stature - Hauer, Nadine; Popp, Bernt; Schoeller, Eva; Schuhmann, Sarah; Heath, Karen E.; Hisado-Oliva, Alfonso; Klinger, Patricia; Kraus, Cornelia; Trautmann, Udo; Zenker, Martin; Zweier, Christiane; Wiesener, Antje; et al. (Genetics in Medicine, 2018)
PurposeShort stature is a common condition of great concern to patients and their families. Mostly genetic in origin, the underlying cause often remains elusive due to clinical and genetic heterogeneity.MethodsWe systematically phenotyped 565 patients where common nongenetic causes of short stature were excluded, selected 200 representative patients for whole-exome sequencing, and analyzed the identified variants for pathogenicity and the affected genes regarding their functional relevance for growth.ResultsBy standard targeted diagnostic and phenotype assessment, we identified a known disease cause in only 13.6% of the 565 patients. Whole-exome sequencing in 200 patients identified additional mutations in known short-stature genes in 16.5% of these patients who manifested only part of the symptomatology. In 15.5% of the 200 patients our findings were of significant clinical relevance. Heterozygous carriers of recessive skeletal dysplasia alleles represented 3.5% of the cases.ConclusionA combined approach of systematic phenotyping, targeted genetic testing, and whole-exome sequencing allows the identification of the underlying cause of short stature in at least 33% of cases, enabling physicians to improve diagnosis, treatment, and genetic counseling. Exome sequencing significantly increases the diagnostic yield and consequently care in patients with short stature.
EVALuna2:34628

Clinicopathologic overview of melanoma - Boßerhoff, Anja Katrin; Strizzi, Luigi (Springer International Publishing, 2017)
Human melanoma is the most rapidly increasing malignant skin disease in Caucasians (Siegel et al. 2015). Once considered a rare disease, the lifetime risk for developing melanoma in the US has increased from approximately 1 in 1500 during the 1930s to its present risk of approximately 1 in 60 (Giblin and Thomas 2007). The American Cancer Society’s recent cancer report estimates that 76,380 new cases of melanoma will be diagnosed and 10,130 deaths will result from melanoma during 2016 in the United States (American Cancer Society 2016). Important risk factors for developing melanoma include increased number of melanocytic nevi, a family history of melanoma, or a history of previous melanoma (Seykora and Elder 1996; Psaty et al. 2010). Prolonged sun exposure associated with increased outdoor activity has been suggested to play an important role in the epidemiologic increase in the incidence of melanoma (Leiter and Garbe 2008; Moan et al. 2008). Acute exposure of the skin to ultraviolet radiation (UVR) can induce varying degrees of erythema, pigmentation, and impairment of immune function (Matsumura and Ananthaswamy 2004). Increased numbers of melanocytic nevi associated with sunburn and intermittent or “holiday” sun exposure has been suggested as a major risk factor for developing melanoma in different studies (Elwood and Jopson 1997; Newton-Bishop et al. 2010). In fact, the Clark model for melanoma suggests a stepwise progression from hyperplastic and dysplastic nevi to melanoma (Clark et al. 1984).
CRIS-Team Scopus Importer:2022-08-05

Cold atmospheric plasma (CAP) activates angiogenesis-related molecules in skin keratinocytes, fibroblasts and endothelial cells and improves wound angiogenesis in an autocrine and paracrine mode - Arndt, Stephanie; Unger, Petra; Berneburg, Mark; Boßerhoff, Anja Katrin; Karrer, Sigrid (Journal of Dermatological Science, 2017)
Cold atmospheric plasma (CAP) emerged as a novel therapeutic field with applications developed for bacterial sterilization, wound healing and cancer treatment. For clinical implementation it is important to know how CAP works and which molecular changes occur after the CAP treatment. Vascularization is an important step during wound healing, however, the effects of CAP on wound angiogenesis are not well examined so far. Furthermore, it has not been investigated, whether CAP primarily affects endothelial cells directly or via paracrine mechanisms to modulate the vasculature.This study concentrates on the influence of CAP on angiogenesis-related molecules in human epidermal keratinocytes, dermal fibroblasts and endothelial cells.CAP was generated by the MicroPlaSter ß® plasma torch system and CAP effects on angiogenesis were determined in vitro and in vivo.We observed that CAP significantly induces the expression of Artemin, EGF, EG-VEGF (PK1), Endothelin-1 (ET-1), FGF-2 (FGF basic), IL-8 (CXCL8) and uPA in keratinocytes and Angiogenin (ANG), Endostatin (Col18A1), MCP-1 (CCL2), MMP-9, TIMP-1, uPA and VEGF in fibroblasts. In addition, CAP activates the expression of Angiopoietin-2 (Ang-2), Angiostatin (PLG), Amphiregulin (AR), Endostatin, FGF-2 and angiogenic-involved receptor expression of FGF R1 and VEGF R1 in HUVEC endothelial cells. It was also demonstrated that supernatants collected from CAP activated fibroblasts and keratinocytes elevate tube formation by endothelial cells and FGF-2 appears to be an important pro-angiogenic factor that controls vascularization via paracrine mechanisms. Mouse experiments supplement that CAP promotes angiogenesis during wound healing in vivo.Taken together, these results suggest that CAP modulates angiogenesis-involved factors via autocrine and paracrine mechanisms and may be used to affect angiogenesis during wound healing.
EVALuna2:4777

Cold atmospheric plasma (CAP) for the selective control of tumor cells - Arndt, S.; Unger, P.; Schneider, C.; Boßerhoff, Anja Katrin; Karrer, S. (EXPERIMENTAL DERMATOLOGY, 2021)
CRIS-Team WoS Importer:2021-05-14

Cold atmospheric plasma causes a calcium influx in melanoma cells triggering CAP-induced senescence - Schneider, Christin; Gebhardt, Lisa; Arndt, Stephanie; Karrer, Sigrid; Zimmermann, Julia L.; Fischer, Michael; Boßerhoff, Anja Katrin (Scientific Reports, 2018)
Cold atmospheric plasma (CAP) is a promising approach in anti-cancer therapy, eliminating cancer cells with high selectivity. However, the molecular mechanisms of CAP action are poorly understood. In this study, we investigated CAP effects on calcium homeostasis in melanoma cells. We observed increased cytoplasmic calcium after CAP treatment, which also occurred in the absence of extracellular calcium, indicating the majority of the calcium increase originates from intracellular stores. Application of previously CAP-exposed extracellular solutions also induced cytoplasmic calcium elevations. A substantial fraction of this effect remained when the application was delayed for one hour, indicating the chemical stability of the activating agent(s). Addition of ryanodine and cyclosporin A indicate the involvement of the endoplasmatic reticulum and the mitochondria. Inhibition of the cytoplasmic calcium elevation by the intracellular chelator BAPTA blocked CAP-induced senescence. This finding helps to understand the molecular influence and the mode of action of CAP on tumor cells.
EVALuna2:185219

Cold atmospheric plasma changes the amino acid composition of solutions and influences the anti‐tumor effect on melanoma cells - Arndt, Stephanie; Fadil, Fadi; Dettmer, Katja; Unger, Petra; Boskovic, Marko; Samol, Claudia; Boßerhoff, Anja Katrin; Zimmermann, Julia L.; Gruber, Michael; Gronwald, Wolfram; Karrer, Sigrid (International Journal of Molecular Sciences, 2021)
Cold Atmospheric Plasma (CAP) is an ionized gas near room temperature. Its anti‐tumor effect can be transmitted either by direct treatment or mediated by a plasma‐treated solution (PTS), such as treated standard cell culture medium, which contains different amino acids, inorganic salts, vitamins and other substances. Despite extensive research, the active components in PTS and its molecular or cellular mechanisms are not yet fully understood. The purpose of this study was the measurement of the reactive species in PTS and their effect on tumor cells using different plasma modes and treatment durations. The PTS analysis yielded mode‐ and dose‐dependent differences in the production of reactive oxygen and nitrogen species (RONS), and in the decomposition and modification of the amino acids Tyrosine (Tyr) and Tryptophan (Trp). The Trp metabolites Formylkynurenine (FKyn) and Kynurenine (Kyn) were produced in PTS with the 4 kHz (oxygen) mode, inducing apoptosis in Mel Im melanoma cells. Nitrated derivatives of Trp and Tyr were formed in the 8 kHz (nitrogen) mode, elevating the p16 mRNA expression and senescence-associated ß‐Galactosidase staining. In conclusion, the plasma mode has a strong impact on the composition of the active components in PTS and affects its anti‐tumor mechanism. These findings are of decisive importance for the development of plasma devices and the effectiveness of tumor treatment.
CRIS-Team Scopus Importer:2021-07-30
Keywords: Amino acid; Anti‐tumor; Apoptosis; Cold atmospheric plasma (CAP); Melanoma; Plasma‐treated solution (PTS); Senescence

Cold Atmospheric Plasma Changes the Amino Acid Composition of Solutions and Influences the Anti-Tumor Effect on Melanoma Cells - Arndt, Stephanie; Fadil, Fadi; Dettmer, Katja; Unger, Petra; Boskovic, Marko; Samol, Claudia; Boßerhoff, Anja Katrin; Zimmermann, Julia L.; Gruber, Michael; Gronwald, Wolfram; Karrer, Sigrid (International Journal of Molecular Sciences, 2021)
Cold Atmospheric Plasma (CAP) is an ionized gas near room temperature. Its anti-tumor effect can be transmitted either by direct treatment or mediated by a plasma-treated solution (PTS), such as treated standard cell culture medium, which contains different amino acids, inorganic salts, vitamins and other substances. Despite extensive research, the active components in PTS and its molecular or cellular mechanisms are not yet fully understood. The purpose of this study was the measurement of the reactive species in PTS and their effect on tumor cells using different plasma modes and treatment durations. The PTS analysis yielded mode- and dose-dependent differences in the production of reactive oxygen and nitrogen species (RONS), and in the decomposition and modification of the amino acids Tyrosine (Tyr) and Tryptophan (Trp). The Trp metabolites Formylkynurenine (FKyn) and Kynurenine (Kyn) were produced in PTS with the 4 kHz (oxygen) mode, inducing apoptosis in Mel Im melanoma cells. Nitrated derivatives of Trp and Tyr were formed in the 8 kHz (nitrogen) mode, elevating the p16 mRNA expression and senescence-associated ß-Galactosidase staining. In conclusion, the plasma mode has a strong impact on the composition of the active components in PTS and affects its anti-tumor mechanism. These findings are of decisive importance for the development of plasma devices and the effectiveness of tumor treatment.

Cold atmospheric plasma promotes the immunoreactivity of granulocytes in vitro - Kupke, Laura S.; Arndt, Stephanie; Lenzer, Simon; Metz, Sophia; Unger, Petra; Zimmermann, Julia L.; Boßerhoff, Anja Katrin; Gruber, Michael; Karrer, Sigrid (Biomolecules, 2021)
Cold atmospheric plasma (CAP) reduces bacteria and interacts with tissues and cells, thus improving wound healing. The CAP-related induction of neutrophils was recently described in stained sections of wound tissue in mice. Consequently, this study aimed to examine the functionality of human polymorphonuclear cells (PMN)/granulocytes through either a plasma-treated solution (PTS) or the direct CAP treatment with different plasma modes and treatment durations. PTS analysis yielded mode-dependent differences in the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) after CAP treatment. Live-cell imaging did not show any chemo-attractive or NETosis-inducing effect on PMNs treated with PTS. The time to maximum ROS production (TmaxROS) in PMNs was reduced by PTS and direct CAP treatment. PMNs directly treated with CAP showed an altered cell migration dependent on the treatment duration as well as decreased TmaxROS without inducing apoptosis. Additionally, flow cytometry showed enhanced integrin and selectin expression, as a marker of activation, on PMN surfaces. In conclusion, the modification of PMN immunoreactivity may be a main supporting mechanism for CAP-induced improvement in wound healing.
CRIS-Team Scopus Importer:2021-06-25
Keywords: Cold atmospheric plasma; Flow cytometry; Granulocytes; Live-cell imaging; NETosis; Wound treatment

Cold atmospheric plasma treatment inhibits growth in colorectal cancer cells - Schneider, Christin; Arndt, Stephanie; Zimmermann, Julia L.; Li, Yangfang; Karrer, Sigrid; Boßerhoff, Anja Katrin (Biological Chemistry, 2018)
Plasma oncology is a relatively new field of research. Recent developments have indicated that cold atmospheric plasma (CAP) technology is an interesting new therapeutic approach to cancer treatment. In this study, p53 wildtype (LoVo) and human p53 mutated (HT29 and SW480) colorectal cancer cells were treated with the miniFlatPlaSter - a device particularly developed for the treatment of tumor cells - that uses the Surface Micro Discharge (SMD) technology for plasma production in air. The present study analyzed the effects of plasma on colorectal cancer cells in vitro and on normal colon tissue ex vivo. Plasma treatment had strong effects on colon cancer cells, such as inhibition of cell proliferation, induction of cell death and modulation of p21 expression. In contrast, CAP treatment of murine colon tissue ex vivo for up to 2 min did not show any toxic effect on normal colon cells compared to H2O2 positive control. In summary, these results suggest that the miniFlatPlaSter plasma device is able to kill colorectal cancer cells independent of their p53 mutation status. Thus, this device presents a promising new approach in colon cancer therapy.
EVALuna2:202900

Cold Atmospheric Plasma Triggers Apoptosis via the Unfolded Protein Response in Melanoma Cells - Zimmermann, Tom; Stäbler, Sebastian; Taudte, R. Verena; Ünüvar, Sumeyya; Groesch, Sabine; Arndt, Stephanie; Karrer, Sigrid; Fromm, Martin; Boßerhoff, Anja Katrin (Cancers, 2023)
Cold atmospheric plasma (CAP) describes a partially ionized gas carrying large amounts of reactive oxygen (ROS) and nitrogen species (RNS). Numerous studies reported strong antitumor activity of CAP, thus rendering it a promising approach for tumor therapy. Although several cellular mechanisms of its cytotoxicity were identified in recent years, the exact molecular effects and contributing signaling pathways are yet to be discovered. We discovered a strong activation of unfolded protein response (UPR) after CAP treatment with increased C/EBP homologous protein (CHOP) expression, which was mainly caused by protein misfolding and calcium loss in the endoplasmic reticulum. In addition, both ceramide level and ceramide metabolism were reduced after CAP treatment, which was then linked to the UPR activation. Pharmacological inhibition of ceramide metabolism resulted in sensitization of melanoma cells for CAP both in vitro and ex vivo. This study identified a novel mechanism of CAP-induced apoptosis in melanoma cells and thereby contributes to its potential application in tumor therapy.
CRIS-Team Scopus Importer:2023-03-10
Keywords: apoptosis; ceramide; cold atmospheric plasma; melanoma; unfolded protein response

Collagen VI is required for the structural and functional integrity of the neuromuscular junction - Cescon, Matilde; Gregorio, Ilaria; Eiber, Nane; Borgia, Doriana; Fusto, Aurora; Sabatelli, Patrizia; Scorzeto, Michele; Megighian, Aram; Pegoraro, Elena; Hashemolhosseini, Said; Bonaldo, Paolo (Acta Neuropathologica, 2018)
The synaptic cleft of the neuromuscular junction (NMJ) consists of a highly specialized extracellular matrix (ECM) involved in synapse maturation, in the juxtaposition of pre- to post-synaptic areas, and in ensuring proper synaptic transmission. Key components of synaptic ECM, such as collagen IV, perlecan and biglycan, are binding partners of one of the most abundant ECM protein of skeletal muscle, collagen VI (ColVI), previously never linked to NMJ. Here, we demonstrate that ColVI is itself a component of this specialized ECM and that it is required for the structural and functional integrity of NMJs. In vivo, ColVI deficiency causes fragmentation of acetylcholine receptor (AChR) clusters, with abnormal expression of NMJ-enriched proteins and re-expression of fetal AChRγ subunit, both in Col6a1 null mice and in patients affected by Ullrich congenital muscular dystrophy (UCMD), the most severe form of ColVI-related myopathies. Ex vivo muscle preparations from ColVI null mice revealed altered neuromuscular transmission, with electrophysiological defects and decreased safety factor (i.e., the excess current generated in response to a nerve impulse over that required to reach the action potential threshold). Moreover, in vitro studies in differentiated C2C12 myotubes showed the ability of ColVI to induce AChR clustering and synaptic gene expression. These findings reveal a novel role for ColVI at the NMJ and point to the involvement of NMJ defects in the etiopathology of ColVI-related myopathies.
EVALuna2:35740

Colocalization analysis of pancreas eQTLs with risk loci from alcoholic and novel non-alcoholic chronic pancreatitis GWAS suggests potential disease causing mechanisms - Schmidt, Andreas W.; Kühnapfel, Andreas; Kirsten, Holger; Grallert, Harald; Hellerbrand, Claus; Kiefer, Falk; Mann, Karl; Mueller, Sebastian; Nöthen, Markus M.; Peters, Annette; Ridinger, Monika; Frank, Josef; et al. (Pancreatology, 2022)
Background: Previous genome-wide association studies (GWAS) identified genome-wide significant risk loci in chronic pancreatitis and investigated underlying disease causing mechanisms by simple overlaps with expression quantitative trait loci (eQTLs), a procedure which may often result in false positive conclusions. Methods: We conducted a GWAS in 584 non-alcoholic chronic pancreatitis (NACP) patients and 6040 healthy controls. Next, we applied Bayesian colocalization analysis of identified genome-wide significant risk loci from both, our recently published alcoholic chronic pancreatitis (ACP) and the novel NACP dataset, with pancreas eQTLs from the GTEx V8 European cohort to prioritize candidate causal genes and extracted credible sets of shared causal variants. Results: Variants at the CTRC (p = 1.22 × 10−21) and SPINK1 (p = 6.59 × 10−47) risk loci reached genome-wide significance in NACP. CTRC risk variants colocalized with CTRC eQTLs in ACP (PP4 = 0.99, PP4/PP3 = 95.51) and NACP (PP4 = 0.99, PP4/PP3 = 95.46). For both diseases, the 95% credible set of shared causal variants consisted of rs497078 and rs545634. CLDN2-MORC4 risk variants colocalized with CLDN2 eQTLs in ACP (PP4 = 0.98, PP4/PP3 = 42.20) and NACP (PP4 = 0.67, PP4/PP3 = 7.18), probably driven by the shared causal variant rs12688220. Conclusions: A shared causal CTRC risk variant might unfold its pathogenic effect in ACP and NACP by reducing CTRC expression, while the CLDN2-MORC4 shared causal variant rs12688220 may modify ACP and NACP risk by increasing CLDN2 expression.
CRIS-Team Scopus Importer:2022-04-08
Keywords: Bayesian colocalization analysis; Chronic pancreatitis; eQTL; GTEx; GWAS

Combined de‐repression of chemoresistance associated mitogen‐activated protein kinase 14 and activating transcription factor 2 by loss of microrna‐622 in hepatocellular carcinoma - Fritz, Valerie; Malek, Lara; Gaza, Anne; Wormser, Laura; Appel, Majken; Kremer, Andreas; Thasler, Wolfgang E.; Neurath, Markus; Hellerbrand, Claus; Boßerhoff, Anja Katrin; Dietrich, Peter; Siebler, Jürgen (Cancers, 2021)
Chemoresistance is a major hallmark driving the progression and poor prognosis of hepatocellular carcinoma (HCC). Limited chemoresponse of HCC was demonstrated to be mediated by mitogen‐activated protein kinase 14 (MAPK14) and activating transcription factor 2 (ATF2). Recently, we have demonstrated loss of control of RAS‐RAF‐ERK‐signaling as a consequence of miR‐622 downregulation in HCC. However, the majority of target genes of this potent tumorsuppressive microRNA had remained elusive. The MAPK14‐ATF2‐axis represents a collateral pathway ensuring persisting ERK‐activation in the presence of sorafenib‐mediated RAF-inhibition. In contrast to the function of the MAPK14‐ATF2‐axis, both the expression and regulation of MAPK14 and ATF2 in human HCC remained to be clarified. We found combined overexpression of MAPK14 and ATF2 in human HCC cells, tissues and in sorafenib resistant cell lines. High expression of MAPK14 and ATF2 was associated with reduced overall survival in HCC patients. Deciphering the molecular mechanism promoting combined upregulation of MAPK14 and ATF2 in HCC, we revealed that miR‐622 directly targets both genes, resulting in combined de‐repression of the MAPK14‐ATF2‐axis. Together, miR‐622 represents a superior regulator of both RAS‐RAF‐ERK as well as MAPK14‐ATF2‐signaling pathways in liver cancer.
CRIS-Team Scopus Importer:2021-03-19
Keywords: HCC; Hepatocellular carcinoma; Liver cancer; MAPK14; MicroRNA; MiR‐622; RAS

Combined effects of PLK1 and RAS in hepatocellular carcinoma reveal rigosertib as promising novel therapeutic "dual-hit" option - Dietrich, Peter; Freese, Kim; Mahli, Abdo; Thasler, Wolfgang Erwin; Hellerbrand, Claus; Boßerhoff, Anja Katrin (Oncotarget, 2018)
Inhibition of RAS-RAF-ERK-signaling is a major mechanism mediated by the multi-kinase inhibitors sorafenib and regorafenib, the only effective therapeutic approaches for advanced hepatocellular carcinoma (HCC). This underlines the importance of RAS-RAF-ERK-signaling in HCC. Most RAS isoforms were not yet described to play crucial roles in HCC. However, several studies indicate that the HRAS isoform can function as potent oncogene in HCC, but pharmacologic RAS inhibition has not yet been investigated. Moreover, the cell cycle promoting polo-like kinase 1 (PLK1) is an increasingly recognized therapeutic target in HCC that can be activated by RAS-RAF-signaling. A recently developed small molecule inhibitor, ON-01910 ("rigosertib", RGS), was shown to interfere with both RAS- and PLK1-signaling. The aim of this study was to analyze the effects of RGS in HCC and to assess PLK1 and HRAS expression in HCC. RGS treatment reduced cell proliferation and induced cell cycle arrest in human HCC cell lines in vitro. Moreover, RGS strongly inhibited both ERK- and AKT-activation in HCC cells, indicating disruption of RAS-signaling. Analysis of HCC patient data showed that PLK1 and HRAS expression levels are upregulated during HCC development and in advanced HCC, respectively. High expression levels of PLK1 significantly correlated with poor patient survival. Moreover, high expression of both PLK1 and HRAS revealed combined effects on patient outcome. This underscores the importance of these genes and associated pathways in HCC. We newly demonstrate the therapeutic potential of RGS in HCC by inhibition of both PLK1 activation and major RAS-pathways, revealing a novel therapeutic "dual-hit" approach for HCC.
EVALuna2:34067

Combined free flaps with arteriovenous loops for reconstruction of extensive thoracic defects after sternal osteomyelitis - Taeger, Christian; Horch, Raymund E.; Arkudas, Andreas; Schmitz, Marweh; Stübinger, Axel; Lang, Werner; Meyer, Alexander; Seitz, Tatjana; Weyand, Michael; Beier, Justus (Microsurgery, 2016)
Various local flaps have been described for patients suffering from sternal osteomyelitis and are regarded as a standard procedure for defect reconstruction. In contrast, the use of microsurgical free flaps has been reported anecdotally only. We present our experiences with the combination of an arteriovenous loop and a free flap transfer in defects larger than half of the sternum.Between January 2012 and October 2014, eight patients with a mean age of 68 years who suffered from extensive deep sternal osteomyelitis were operated in a consecutive series. After radical surgical debridement, the defect size comprised all three thirds of the sternum. Defect reconstruction was achieved by means of free flap transplantation using the vastus lateralis myocutaneous flap, rectus abdominis, and bipedicled latissimus dorsi/parascapular flap. As local recipient vessels were depleted in all patients, the pedicle of the flap was anastomosed to a high-flow and short-length subclavian arteriovenous loop as recipient vessel in all cases.The immediate postoperative course in all patients was uneventful despite one axonal injury to the femoral nerve at the donor site. There was no partial or total flap loss. During a mean follow-up of 9 months, one patient suffered from a local infection at the donor site. In all patients, a successful defect reconstruction could be achieved.Depletion of local recipient vessels as an obstacle for free flap reconstruction can be overcome by creating an arteriovenous loop. Even extensive defects are adequate for defect reconstruction using a single or, in extreme cases, bipedicled free flap. © 2015 Wiley Periodicals, Inc. Microsurgery 36:121-127, 2016.
EVALuna2:15222

Common RUNX3 missense variant contributes to psoriatic arthritis by affecting splicing and modifying signaling, activation and differentiation of T-cells - Hüffmeier, Ulrike; Löhr, Sabine; Uebe, Steffen; Popp, Bernt; Bowes, J.; Kirchner, P.; Giardina, E.; Korendowych, E.; Ekici, Arif Bülent; Ho, P.; Behrens, F.; Koehm, M.; et al. (EUROPEAN JOURNAL OF HUMAN GENETICS, 2020)
CRIS-Team WoS Importer:2021-01-22

Common RUNX3 missense variant contributes to psoriatic arthritis by modifying differentiation of CD8(+) T-cells - Kerker, Iris; Löhr, Sabine; Uebe, Steffen; Popp, Bernt; Vasileiou, Georgia; Bowes, John; Kirchner, Philipp; Becker, Ina; Giardina, Emiliano; Korendowych, Eleanor; Ekici, Arif Bülent; Ho, Pauline; et al. (EUROPEAN JOURNAL OF HUMAN GENETICS, 2022)
CRIS-Team WoS Importer:2022-05-06

Common schizophrenia risk variants are enriched in open chromatin regions of human glutamatergic neurons - Hauberg, Mads E.; Creus-Muncunill, Jordi; Bendl, Jaroslav; Kozlenkov, Alexey; Zeng, Biao; Corwin, Chuhyon; Chowdhury, Sarah; Kranz, Harald; Hurd, Yasmin L.; Wegner, Michael; Børglum, Anders D.; Dracheva, Stella; et al. (Nature Communications, 2020)
The chromatin landscape of human brain cells encompasses key information to understanding brain function. Here we use ATAC-seq to profile the chromatin structure in four distinct populations of cells (glutamatergic neurons, GABAergic neurons, oligodendrocytes, and microglia/astrocytes) from three different brain regions (anterior cingulate cortex, dorsolateral prefrontal cortex, and primary visual cortex) in human postmortem brain samples. We find that chromatin accessibility varies greatly by cell type and, more moderately, by brain region, with glutamatergic neurons showing the largest regional variability. Transcription factor footprinting implicates cell-specific transcriptional regulators and infers cell-specific regulation of protein-coding genes, long intergenic noncoding RNAs and microRNAs. In vivo transgenic mouse experiments validate the cell type specificity of several of these human-derived regulatory sequences. We find that open chromatin regions in glutamatergic neurons are enriched for neuropsychiatric risk variants, particularly those associated with schizophrenia. Integration of cell-specific chromatin data with a bulk tissue study of schizophrenia brains increases statistical power and confirms that glutamatergic neurons are most affected. These findings illustrate the utility of studying the cell-type-specific epigenome in complex tissues like the human brain, and the potential of such approaches to better understand the genetic basis of human brain function.
CRIS-Team Scopus Importer:2020-11-13

Comparative analysis of gene expression profiles between cortex and thalamus in Chinese fatal familial insomnia patients - Tian, Chan; Liu, Di; Sun, Qing-Lan; Chen, Chen; Xu, Yin; Wang, Hui; Xiang, Wei; Kretzschmar, Hans A.; Li, Wei; Chen, Cao; Shi, Qi; Gao, Chen; et al. (Molecular Neurobiology, 2013)
Fatal familial insomnia (FFI) is a special subtype of genetic human prion diseases that is caused by the D178N mutation of the prion protein gene (PRNP). According to the surveillance data from 2006, FFI accounts for about half of all genetic prion disease cases in China. In this study, global expression patterns of the thalamus and parietal cortex from three patients with FFI were analyzed by Affymetrix Human Genome U133+ 2.0 chip. A total of 1,314 genes in the thalamus and 332 ones in the parietal lobe were determined to be differentially expressed genes (DEGs). The percentage of upregulated DEGs is much less in the thalamus (19.3 %) than that in the parietal lobe (42.8 %). Moreover, 255 of those DEGs showed the same altering tendencies in both tested regions, including 99 upregulated and 156 downregulated ones. The reliability of the results was confirmed by the real-time RT-PCR assays. There were 1,152 and 531 biological processes affected in the thalamus and the parietal lobe, respectively, as well as 391 overlapping ones in both regions. The most significantly changed molecular functions included transcription and DNA-dependent regulation of transcription, RNA splicing, mitochondrial electron transport, etc. The changed functions in the thalamus contained more numbers of DEGs than parietal lobe. According to KEGG classification, there were 167 and 115 different pathways changed in the thalamus and the parietal lobe, respectively, while 102 were changed in both. Interestingly, the top three changed pathways in the three groups mentioned above were Parkinson's disease, Alzheimer's disease, and oxidative phosphorylation. These results demonstrate the greater damage in the thalamus than in the parietal lobe during FFI pathogenesis, which is consistent with previous pathological observations. This study aims to describe the global expression profiles in various brain regions of FFI while proposing useful clues for understanding the pathogenesis of FFI and selecting potential biomarkers for diagnostic and therapeutic tools.
EVALuna2:4687

Comparison of Early Retinal Microvascular Changes and Microalbuminuria as Indicators for Increased Cardioascular Risk - Huchzermeyer, Cord; Schaller, Barbara; Schmid, Kathrin; Schmieder, Roland; Michelson, Georg (Klinische Monatsblätter für Augenheilkunde, 2011)
Prevention of cardiovascular disease is an important goal in clinical medicine and public health. In the process, the diagnosis of early end-organ damage is a priority beside the treatment of classic cardiovascular risk factors. To achieve this, the ophthalmoscopic examination of the retinal vessels plays a prominent role. Alternatively, the quantification of low quantities of albumin in the urine (microalbuminuria) allows the detection of early vascular damage in the kidney. The question is addressed as to whether these two methods are interchangeable or are rather complementary.We examined 226 members of the staff of the University Hospital Erlangen who volunteered to participate in a preventive campaign. A comprehensive history was taken, and height, weight and blood pressure were measured. Analysis of serum lipids and determination of the urinary albumin/creatinine ratio were performed. Fotos of the central fundus were taken with a non-mydriatic camera and analysed by an experienced ophthalmologist in a standardised fashion. The risk for cardiovascular mortality within the next ten years was estimated from age, sex, blood pressure and serum cholesterol using the euroSCORE tables for Germany.There was no signficant correlation between the arteriovenous ratio of the retinal vessels and the urinary albumin/creatinine ratio. Neither parameter correlated with the euroSCORE Germany. Arteriovenous crossings and focal narrowing of the retinal vessels were associated signficantly with an elevated euroSCORE risk.In large population-based studies, the arteriovenous ratio and the urinary albumin/creatinine ratio have been confirmed as markers of cardiovascular risk. In our study, there was no correlation between these two parameters. Thus, they seem to present independent risk markers. The presence of arteriovenous crossings and focal narrowing seems to be linked more closely to the classic cardiovascular risk factors from which the euroSCORE is calculated. The ophathlmolscopic examination of retinal vessels and the analysis of urinary albumin/creatinine ratio seem to complement rather than replace each other.
EVALuna2:3434

Comparison of hydrogels for the development of well-defined 3d cancer models of breast cancer and melanoma - Schmid, Rafael; Schmidt, Sonja; Hazur, Jonas; Detsch, Rainer; Maurer, Evelyn; Boccaccini, Aldo R.; Hauptstein, Julia; Teßmar, Jörg; Blunk, Torsten; Schrüfer, Stefan; Schubert, Dirk W.; Horch, Raymund E.; et al. (Cancers, 2020)
Bioprinting offers the opportunity to fabricate precise 3D tumor models to study tumor pathophysiology and progression. However, the choice of the bioink used is important. In this study, cell behavior was studied in three mechanically and biologically different hydrogels (alginate, alginate dialdehyde crosslinked with gelatin (ADA–GEL), and thiol-modified hyaluronan (HA-SH crosslinked with PEGDA)) with cells from breast cancer (MDA-MB-231 and MCF-7) and melanoma (Mel Im and MV3), by analyzing survival, growth, and the amount of metabolically active, living cells via WST-8 labeling. Material characteristics were analyzed by dynamic mechanical analysis. Cell lines revealed significantly increased cell numbers in low-percentage alginate and HA-SH from day 1 to 14, while only Mel Im also revealed an increase in ADA–GEL. MCF-7 showed a preference for 1% alginate. Melanoma cells tended to proliferate better in ADA– GEL and HA-SH than mammary carcinoma cells. In 1% alginate, breast cancer cells showed equally good proliferation compared to melanoma cell lines. A smaller area was colonized in high-percentage alginate-based hydrogels. Moreover, 3% alginate was the stiffest material, and 2.5% ADA–GEL was the softest material. The other hydrogels were in the same range in between. Therefore, cellular responses were not only stiffness-dependent. With 1% alginate and HA-SH, we identified matrices that enable proliferation of all tested tumor cell lines while maintaining expected tumor heterogeneity. By adapting hydrogels, differences could be accentuated. This opens up the possibility of understanding and analyzing tumor heterogeneity by biofabrication.
CRIS-Team Scopus Importer:2020-08-28
Keywords: Biofabrication; Breast cancer; Hydrogel; Melanoma; Tumor heterogeneity

Comparison of the Serum Tumor Markers S100 and Melanoma-inhibitory Activity (MIA) in the Monitoring of Patients with Metastatic Melanoma Receiving Vaccination Immunotherapy with Dendritic Cells - Uslu, Ugur; Schliep, Stefan; Schliep, Klaus; Erdmann, Michael; Koch, Hans-Uwe; Parsch, Hans; Rosenheinrich, Stina; Anzengruber, Doris; Boßerhoff, Anja Katrin; Schuler, Gerold; Schuler-Thurner, Beatrice (Anticancer Research, 2017)
In patients with melanoma, early dissemination via lymphatic and hematogenous routes is frequently seen. Thus, besides clinical follow-up examination and imaging, reliable melanoma-specific serological tumor markers are needed.We retrospectively compared two serum markers for melanoma, S100 and melanoma-inhibitory activity (MIA), for monitoring of patients with metastatic melanoma under either adjuvant or therapeutic vaccination immunotherapy with dendritic cells (DC). Serum was obtained from a total of 100 patients (28 patients in stage III and 72 patients in stage IV, according to the American Joint Committee on Cancer 2002) at regular intervals during therapy, accompanied by follow-up imaging.When relapse was detected, both markers often remained within normal range. In contrast, in patients with metastatic measurable disease receiving therapeutic and not adjuvant DC vaccination, an increase of both markers was a strong indicator for disease progression. When comparing both markers in the whole study population, MIA showed a superior sensitivity to detect disease progression.S100 and MIA are highly sensitive tumor markers for monitoring of patients with melanoma with current metastases, but less sensitive for monitoring of tumor-free patients. In the current study, MIA had a slightly superior sensitivity to detect progressive disease compared to S100 and seems to be more useful in monitoring of patients with metastatic melanoma receiving immunotherapy.
EVALuna2:4755

Compensatory neuritogenesis of serotonergic afferents within the striatum of a transgenic rat model of Parkinson's disease - Stemick, Judith; Gauer, Carina; Wihan, Jeanette; Moceri, Sandra; Xiang, Wei; von Hörsten, Stephan; Kohl, Zacharias; Winkler, Jürgen (Brain Research, 2020)
The majority of patients with Parkinson's disease (PD) suffer from L-DOPA-induced dyskinesia (LID). Besides a dysfunctional dopaminergic system, changes of the serotonergic network may be linked to this severe and adverse symptom. Particularly, serotonergic neurons have the potential to synthesize dopamine, likely associated with a disproportional dopamine release within the striatum. We hypothesized that the serotonergic system is adaptively altered in the striatum due to the reduced dopaminergic input. To answer this question, we analyzed a transgenic rat PD model ubiquitously expressing human α-synuclein using a bacterial artificial chromosome. Neurite analysis showed a profound loss of dopaminergic fibers by 30–40% within the dorsal striatum paralleled by a 50% reduction of dopaminergic neurons in the substantia nigra pars compacta. In contrast, serotonergic fibers showed an increased fiber density in the dorsal striatum by 100%, while the number of serotonergic neurons within the raphe nuclei (RN) and its proximal neuritic processes were unaffected. Furthermore, both the dopaminergic and serotonergic fiber density remained unchanged in the neighboring motor cortex M1/M2. Interestingly, essential enzymes required for L-DOPA turnover and dopamine release were expressed in serotonergic neurons of the RN. In parallel, the serotonergic autoreceptor levels involved in a serotonergic negative feedback loop were reduced within the striatum, suggesting a dysfunctional neurotransmitter release. Overall, the increased serotonergic fiber density with its capacity for dopamine release within the striatum suggests a compensatory, site-specific serotonergic neuritogenesis. This maladaptive serotonergic plasticity may be linked to adverse symptoms such as LIDs in PD.
CRIS-Team Scopus Importer:2020-10-02
Keywords: Dopamine; L-DOPA-induced dyskinesia; Parkinson's disease; Serotonin; Striatum; α-synuclein

Competing waves of oligodendrocytes in the forebrain and postnatal elimination of an early embryonic lineage. - Wegner, Michael; et al. (Nature Neuroscience, 2006)
UnivIS-Import:2015-03-09:Pub.2006.med.IB.LPCIPDBI.compet