Special characteristics of the transcription and splicing machinery in photoreceptor cells of the mammalian retina - Derlig, Kristin; Gießl, Andreas; Brandstätter, Johann Helmut; Enz, Ralf; Dahlhaus, Regina (Cell and Tissue Research, 2015)
Chromatin organization and the management of transcription and splicing are fundamental to the correct functioning of every cell but, in particular, for highly active cells such as photoreceptors, the sensory neurons of the retina. Rod photoreceptor cells of nocturnal animals have recently been shown to have an inverted chromatin architecture compared with rod photoreceptor cells of diurnal animals. The heterochromatin is concentrated in the center of the nucleus, whereas the genetically active euchromatin is positioned close to the nuclear membrane. This unique chromatin architecture suggests that the transcription and splicing machinery is also subject to specific adaptations in these cells. Recently, we described the protein Simiate, which is enriched in nuclear speckles and seems to be involved in transcription and splicing processes. Here, we examine the distribution of Simiate and nuclear speckles in neurons of mouse retinae. In retinal neurons of the inner nuclear and ganglion cell layer, Simiate is concentrated in a clustered pattern in the nuclear interior, whereas in rod and cone photoreceptor cells, Simiate is present at the nuclear periphery. Further staining with markers for the transcription and splicing machinery has confirmed the localization of nuclear speckle components at the periphery. Comparing the distribution of nuclear speckles in retinae of the nocturnal mouse with the diurnal degu, we found no differences in the arrangement of the transcription and splicing machinery in their photoreceptor cells, thus suggesting that the organization of these machineries is not related to the animal's lifestyle but rather represents a general characteristic of photoreceptor organization and function.
EVALuna2:4722

Specific c-Jun target genes in malignant melanoma - Schummer, Patrick; Kuphal, Silke; Vardimon, Lily; Boßerhoff, Anja Katrin; Kappelmann, Melanie (Cancer Biology & Therapy, 2016)
A fundamental event in the development and progression of malignant melanoma is the de-regulation of cancer-relevant transcription factors. We recently showed that c-Jun is a main regulator of melanoma progression and, thus, is the most important member of the AP-1 transcription factor family in this disease. Surprisingly, no cancer-related specific c-Jun target genes in melanoma were described in the literature, so far. Therefore, we focused on pre-existing ChIP-Seq data (Encyclopedia of DNA Elements) of 3 different non-melanoma cell lines to screen direct c-Jun target genes. Here, a specific c-Jun antibody to immunoprecipitate the associated promoter DNA was used. Consequently, we identified 44 direct c-Jun targets and a detailed analysis of 6 selected genes confirmed their deregulation in malignant melanoma. The identified genes were differentially regulated comparing 4 melanoma cell lines and normal human melanocytes and we confirmed their c-Jun dependency. Direct interaction between c-Jun and the promoter/enhancer regions of the identified genes was confirmed by us via ChIP experiments. Interestingly, we revealed that the direct regulation of target gene expression via c-Jun can be independent of the existence of the classical AP-1 (5´-TGA(C/G)TCA-3´) consensus sequence allowing for the subsequent down- or up-regulation of the expression of these cancer-relevant genes. In summary, the results of this study indicate that c-Jun plays a crucial role in the development and progression of malignant melanoma via direct regulation of cancer-relevant target genes and that inhibition of direct c-Jun targets through inhibition of c-Jun is a potential novel therapeutic option for treatment of malignant melanoma.
EVALuna2:4713

Specific engineered G protein coupling to histamine receptors revealed from cellular assay experiments and accelerated molecular dynamics simulations - Höring, Carina; Conrad, Marcus; Söldner, Christian; Wang, Jinan; Sticht, Heinrich; Strasser, Andrea; Miao, Yinglong (International Journal of Molecular Sciences, 2021)
G protein-coupled receptors (GPCRs) are targets of extracellular stimuli and hence occupy a key position in drug discovery. By specific and not yet fully elucidated coupling profiles with α subunits of distinct G protein families, they regulate cellular responses. The histamine H2 and H4 receptors (H2R and H4R) are prominent members of Gs-and Gi-coupled GPCRs. Neverthe-less, promiscuous G protein and selective Gi signaling have been reported for the H2R and H4R, respectively, the molecular mechanism of which remained unclear. Using a combination of cellular experimental assays and Gaussian accelerated molecular dynamics (GaMD) simulations, we investigated the coupling profiles of the H2R and H4R to engineered mini-G proteins (mG). We obtained coupling profiles of the mGs, mGsi, or mGsq proteins to the H2R and H4R from the mini-G protein recruitment assays using HEK293T cells. Compared to H2R–mGs expressing cells, histamine responses were weaker (pEC50, Emax) for H2R–mGsi and –mGsq. By contrast, the H4R selectively bound to mGsi. Similarly, in all-atom GaMD simulations, we observed a preferential binding of H2R to mGs and H4R to mGsi revealed by the structural flexibility and free energy landscapes of the complexes. Although the mG α5 helices were consistently located within the HR binding cavity, alternative binding orientations were detected in the complexes. Due to the specific residue interactions, all mG α5 helices of the H2R complexes adopted the Gs-like orientation toward the receptor transmembrane (TM) 6 domain, whereas in H4R complexes, only mGsi was in the Gi-like orientation toward TM2, which was in agreement with Gs-and Gi-coupled GPCRs structures resolved by X-ray/cryo-EM. These cellular and molecular insights support (patho)physiological profiles of the histamine receptors, especially the hitherto little studied H2R function in the brain, as well as of the pharmacological potential of H4R selective drugs.
CRIS-Team Scopus Importer:2021-10-01
Keywords: Engineered G proteins; Gaussian accelerated molecular dynamics (GaMD); GPCR–G protein coupling profiles; Histamine H; Histamine H; Histamine signaling; Split-luciferase complementation assay

Specific residues of a conserved domain in the N terminus of the human cytomegalovirus pUL50 protein determine its intranuclear interaction with pUL53 - Milbradt, Jens; Auerochs, Sabrina; Sevvana, Madhumati; Muller, Yves; Sticht, Heinrich; Marschall, Manfred (Journal of Biological Chemistry, 2012)
Herpesviral capsids are assembled in the host cell nucleus and are subsequently translocated to the cytoplasm. During this process it has been demonstrated that the human cytomegalovirus proteins pUL50 and pUL53 interact and form, together with other viral and cellular proteins, the nuclear egress complex at the nuclear envelope. In this study we provide evidence that specific residues of a conserved N-terminal region of pUL50 determine its intranuclear interaction with pUL53. In silico evaluation and biophysical analyses suggested that the conserved region forms a regular secondary structure adopting a globular fold. Importantly, site-directed replacement of individual amino acids by alanine indicated a strong functional influence of specific residues inside this globular domain. In particular, mutation of the widely conserved residues Glu-56 or Tyr-57 led to a loss of interaction with pUL53. Consistent with the loss of binding properties, mutants E56A and Y57A showed a defective function in the recruitment of pUL53 to the nuclear envelope in expression plasmid-transfected and human cytomegalovirus-infected cells. In addition, in silico analysis suggested that residues 3-20 form an amphipathic ?-helix that appears to be conserved among Herpesviridae. Point mutants revealed a structural role of this N-terminal ?-helix for pUL50 stability rather than a direct role in the binding of pUL53. In contrast, the central part of the globular domain including Glu-56 and Tyr-57 is directly responsible for the functional interaction with pUL53 and thus determines formation of the basic nuclear egress complex.
EVALuna2:8148

STEATOSIS: A LUBRICANT FOR THE DEVELOPMENT AND PROGRESSION OF ALCOHOLIC LIVER DISEASE - Mahli, Abdo; Sommer, Judith; Koch, A.; Hellerbrand, Claus (ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH, 2021)
CRIS-Team WoS Importer:2021-07-02

Stem cell factor Sox2 and its close relative Sox3 have differentiation functions in oligodendrocytes - Hoffmann, Stephanie Annie; Hos, Deniz; Küspert, Melanie; Lang, Richard A.; Lovell-Badge, Robin; Wegner, Michael; Reiprich, Simone (Development, 2014)
Neural precursor cells of the ventricular zone give rise to all neurons and glia of the central nervous system and rely for maintenance of their precursor characteristics on the closely related SoxB1 transcription factors Sox1, Sox2 and Sox3. We show in mouse spinal cord that, whereas SoxB1 proteins are usually downregulated upon neuronal specification, they continue to be expressed in glial precursors. In the oligodendrocyte lineage, Sox2 and Sox3 remain present into the early phases of terminal differentiation. Surprisingly, their deletion does not alter precursor characteristics but interferes with proper differentiation. Although a direct influence on myelin gene expression may be part of their function, we provide evidence for another mode of action. SoxB1 proteins promote oligodendrocyte differentiation in part by negatively controlling miR145 and thereby preventing this microRNA from inhibiting several pro-differentiation factors. This study presents one of the few cases in which SoxB1 proteins, including the stem cell factor Sox2, are associated with differentiation rather than precursor functions.
EVALuna2:4939

Stem cell maintenance in the adult mammalian hippocampus: a matter of signal integration? - Schwarz, Tobias J.; Ebert, Birgit; Lie, Dieter Chichung (Developmental Neurobiology, 2012)
The continuous generation of new neurons from stem cells in the hippocampal dentate gyrus is considered an important contributor to hippocampal plasticity. A prerequisite for the life-long generation of new dentate granule neurons is the maintenance of the neural stem cell pool. A number of essential molecular regulators and signals for hippocampal neural stem cell maintenance have been identified, but how these pathways interact to prevent precocious differentiation or exhaustion of the stem cell pool is currently unknown. Here, we summarize the current knowledge on the molecular regulation of the hippocampal stem cell pool and discuss the possibility that signal integration through Notch signaling controls stem cell maintenance in the adult hippocampus.
EVALuna2:26315

Store-operated calcium entry is reduced in spastin-linked hereditary spastic paraplegia - Winner, Beate; Rizo Garza, Tania; Gebhardt, Lisa; Riedlberger, Julia; Eberhardt, Esther; Fester, Lars; Alansary, Dalia; Winkler, Jürgen; Turan, Sören; Arnold, Philipp; Niemeyer, Barbara; Fischer, Michael (2022)
Pathogenic variants in SPAST, the gene coding for spastin, are the single most common cause of hereditary spastic paraplegia, a progressive motor neuron disease. Spastin regulates key cellular functions, including microtubule-severing and endoplasmic reticulum-morphogenesis. However, it remains unclear how alterations in these cellular functions due to SPAST pathogenic variants result in motor neuron dysfunction. Since spastin influences both microtubule network and endoplasmic reticulum structure, we hypothesized that spastin is necessary for the regulation of Ca2+ homeostasis via store-operated calcium entry. Here, we show that the lack of spastin enlarges the endoplasmic reticulum and reduces store-operated calcium entry. In addition, elevated levels of different spastin variants induced clustering of STIM1 within the endoplasmic reticulum, altered the transport of STIM1 to the plasma membrane and reduced store-operated calcium entry, which could be rescued by exogenous expression of STIM1. Importantly, store-operated calcium entry was strongly reduced in induced pluripotent stem cell-derived neurons from hereditary spastic paraplegia patients with pathogenic variants in SPAST resulting in spastin haploinsufficiency. These neurons developed axonal swellings in response to lack of spastin. We were able to rescue both store-operated calcium entry and axonal swellings in SPAST patient neurons by restoring spastin levels, using CRISPR/Cas9 to correct the pathogenic variants in SPAST. These findings demonstrate that proper amounts of spastin are a key regulatory component for store-operated calcium entry mediated Ca2+ homeostasis and suggest store-operated calcium entry as a disease relevant mechanism of spastin-linked motor neuron disease.Rizo et al. use iPSC-derived neurons from patients to investigate how pathogenic variants in SPAST give rise to hereditary spastic paraplegia. They show that dysregulation of spastin, a microtubule- and ER-remodelling protein encoded by SPAST, alters the dynamics of the ER, resulting in aberrant Ca2+ regulation.
Keywords: spastin; STIM1; microtubules; endoplasmic reticulum; store-operated calcium entry

Storkhead box 2 and melanoma inhibitory activity promote oral squamous cell carcinoma progression - Sasahira, Tomonori; Nishiguchi, Yukiko; Fujiwara, Rina; Kurihara, Miyako; Kirita, Tadaaki; Boßerhoff, Anja Katrin; Kuniyasu, Hiroki (Oncotarget, 2016)
Storkhead box protein 2 (STOX2) is a transcriptional factor associated with pre-eclampsia with fetal growth restriction. We recently reported that melanoma inhibitory activity (MIA) promotes oral squamous cell carcinoma (OSCC) progression. However, the relationship between STOX2 and MIA remains unknown in malignancies.We used immunohistochemistry and PCR to investigate MIA and STOX2 expression in OSCC. We also performed functional analysis in human OSCC cells.MIA and STOX2 mRNA levels were higher in OSCCs than in normal oral epithelial cells, and upregulation of STOX2 was significantly correlated with overexpression of MIA. Immunostaining for STOX2 was associated with nodal metastasis (P = 0.0002) and MIA expression (P < 0.0001). Furthermore, MIA expression (P = 0.0035) and STOX2 expression (P = 0.0061) were associated with poor outcome in OSCCs. In vitro analysis using OSCC cells revealed that MIA increased expression of STOX2 by paracrine manner. Moreover, STOX2 accelerated OSCC cell growth, invasion, suppressed apoptosis, and enhanced resistance to paclitaxel, cisplatin, and 5-FU.Our results suggest that MIA-STOX2 signaling may be a useful diagnostic and therapeutic target in OSCCs.
EVALuna2:4731

Striking parallels between carotid body glomus cell and adrenal chromaffin cell development - Hockman, Dorit; Adameyko, Igor; Kaucka, Marketa; Barraud, Perrine; Otani, Tomoki; Hunt, Adam; Hartwig, Anna; Sock, Elisabeth; Waithe, Dominic; Franck, Marina C.M.; Ernfors, Patrik; Ehinger, Sean; et al. (Developmental Biology, 2018)
Carotid body glomus cells mediate essential reflex responses to arterial blood hypoxia. They are dopaminergic and secrete growth factors that support dopaminergic neurons, making the carotid body a potential source of patient-specific cells for Parkinson's disease therapy. Like adrenal chromaffin cells, which are also hypoxia-sensitive, glomus cells are neural crest-derived and require the transcription factors Ascl1 and Phox2b; otherwise, their development is little understood at the molecular level. Here, analysis in chicken and mouse reveals further striking molecular parallels, though also some differences, between glomus and adrenal chromaffin cell development. Moreover, histology has long suggested that glomus cell precursors are 'émigrés' from neighbouring ganglia/nerves, while multipotent nerve-associated glial cells are now known to make a significant contribution to the adrenal chromaffin cell population in the mouse. We present conditional genetic lineage-tracing data from mice supporting the hypothesis that progenitors expressing the glial marker proteolipid protein 1, presumably located in adjacent ganglia/nerves, also contribute to glomus cells. Finally, we resolve a paradox for the 'émigré' hypothesis in the chicken - where the nearest ganglion to the carotid body is the nodose, in which the satellite glia are neural crest-derived, but the neurons are almost entirely placode-derived - by fate-mapping putative nodose neuronal 'émigrés' to the neural crest.
EVALuna2:35753

Stromal cell regulation of inflammatory responses - Friscic, Jasna; Hoffmann, Markus (Current Opinion in Immunology, 2022)
In the last fifteen years it has become apparent that tissue resident mesenchymal cells such as fibroblasts, which are the structural elements of all organs, play a cardinal role in the pathology of immune-mediated inflammatory diseases. We now know that all fibroblasts originate from universal pan organ cellular ancestors and that they are diversified into more specific subsets according to the functional needs of their home tissue-and its activation state. In arthritis, a plethora of activated joint-resident and migrating fibroblast types have been recently described that are central for pathogenesis and persistence of inflammatory joint-disease. Here we provide a current overview on the multiple inflammatory and immune related functions of fibroblasts and how they could be curbed to induce long-lasting abatement of disease.
CRIS-Team WoS Importer:2021-12-10

Structural analysis of the protein phosphatase 1 docking motif: Molecular description of the binding specificity identifies new ligands. - Meiselbach, Heike; Sticht, Heinrich; Enz, Ralf (Chemistry & Biology, 2006)
The interplay between kinases and phosphatases represents a fundamental regulatory mechanism in biological systems. Being less numerous than kinases, phosphatases increase their diversity by the acquisition of a variety of binding partners, thereby forming a large number of holoenzymes. Proteins interacting with protein phosphatase 1 (PP1) often bind via a so-called docking motif to regulate its enzymatic activity, substrate specificity, and subcellular localization. Here, we systematically determined structural elements that mediate the binding specificity of PP1 interacting proteins, and propose a refined consensus sequence for high-affinity PP1 ligands. Applying this pattern to database searches, we predicted and experimentally confirmed several previously unknown PP1 interactors. Thus, the suggested PP1 docking motif enables a highly specific prediction of PP1 binding partners, thereby facilitating the genome-wide identification of PP1 interactors.<br
UnivIS-Import:2015-04-14:Pub.2006.med.IB.profes_1.struct

Structural and functional dissection reveals distinct roles of Ca2+-binding sites in the giant adhesin SiiE of Salmonella enterica - Peters, Britta; Stein, Johanna; Klingl, Stefan; Sander, Nathalie; Sandmann, Achim; Taccardi, Nicola; Sticht, Heinrich; Gerlach, Roman; Muller, Yves; Hensel, Michael (PLoS Pathogens, 2017)

Structural and functional dissection reveals distinct roles of Ca2+-binding sites in the giant adhesin SiiE of Salmonella enterica - Peters, Britta; Stein, Johanna; Klingl, Stefan; Sander, Nathalie; Sandmann, Achim; Taccardi, Nicola; Sticht, Heinrich; Gerlach, Roman G.; Muller, Yves; Hensel, Michael (PLoS Pathogens, 2017)

Structural and functional rejuvenation of the aged brain by an approved anti-asthmatic drug - Marschallinger, Julia; Schäffner, Iris; Klein, Barbara; Gelfert, Renate; Rivera, Francisco J.; Illes, Sebastian; Grassner, Lukas; Janssen, Maximilian; Rotheneichner, Peter; Schmuckermair, Claudia; Coras, Roland; Boccazzi, Marta; et al. (Nature Communications, 2015)
As human life expectancy has improved rapidly in industrialized societies, age-related cognitive impairment presents an increasing challenge. Targeting histopathological processes that correlate with age-related cognitive declines, such as neuroinflammation, low levels of neurogenesis, disrupted blood-brain barrier and altered neuronal activity, might lead to structural and functional rejuvenation of the aged brain. Here we show that a 6-week treatment of young (4 months) and old (20 months) rats with montelukast, a marketed anti-asthmatic drug antagonizing leukotriene receptors, reduces neuroinflammation, elevates hippocampal neurogenesis and improves learning and memory in old animals. By using gene knockdown and knockout approaches, we demonstrate that the effect is mediated through inhibition of the GPR17 receptor. This work illustrates that inhibition of leukotriene receptor signalling might represent a safe and druggable target to restore cognitive functions in old individuals and paves the way for future clinical translation of leukotriene receptor inhibition for the treatment of dementias.
EVALuna2:7294

Structural Basis for Species Selectivity in the HIV-1 gp120-CD4 Interaction: Restoring Affinity to gp120 in Murine CD4 Mimetic Peptides - Kaßler, Kristin; Meier, Julia; Eichler, Jutta; Sticht, Heinrich (Advances in Bioinformatics, 2011)
The first step of HIV-1 infection involves interaction between the viral glycoprotein gp120 and the human cellular receptor CD4. Inhibition of the gp120-CD4 interaction represents an attractive strategy to block HIV-1 infection. In an attempt to explore the known lack of affinity of murine CD4 to gp120, we have investigated peptides presenting the putative gp120-binding site of murine CD4 (mCD4). Molecular modeling indicates that mCD4 protein cannot bind gp120 due to steric clashes, while the larger conformational flexibility of mCD4 peptides allows an interaction. This finding is confirmed by experimental binding assays, which also evidenced specificity of the peptide-gp120 interaction. Molecular dynamics simulations indicate that the mCD4-peptide stably interacts with gp120 via an intermolecular ?-sheet, while an important salt-bridge formed by a C-terminal lysine is lost. Fixation of the C-terminus by introducing a disulfide bridge between the N- and C-termini of the peptide significantly enhanced the affinity to gp120.
EVALuna2:26276

Structural Basis for the Recognition of Human Cytomegalovirus Glycoprotein B by a Neutralizing Human Antibody - Spindler, Nadja; Diestel, Uschi; Stump, Joachim; Wiegers, Anna-Katharina; Winkler, Thomas; Sticht, Heinrich; Mach, Michael; Muller, Yves (PLoS Pathogens, 2014)
Human cytomegalovirus (HCMV) infections are life-threating to people with a compromised or immature immune system. Upon adhesion, fusion of the virus envelope with the host cell is initiated. In this step, the viral glycoprotein gB is considered to represent the major fusogen. Here, we present for the first time structural data on the binding of an anti-herpes virus antibody and describe the atomic interactions between the antigenic domain Dom-II of HCMV gB and the Fab fragment of the human antibody SM5-1. The crystal structure shows that SM5-1 binds Dom-II almost exclusively via only two CDRs, namely light chain CDR L1 and a 22-residue-long heavy chain CDR H3. Two contiguous segments of Dom-II are targeted by SM5-1, and the combining site includes a hydrophobic pocket on the Dom-II surface that is only partially filled by CDR H3 residues. SM5-1 belongs to a series of sequence-homologous anti-HCMV gB monoclonal antibodies that were isolated from the same donor at a single time point and that represent different maturation states. Analysis of amino acid substitutions in these antibodies in combination with molecular dynamics simulations show that key contributors to the picomolar affinity of SM5-1 do not directly interact with the antigen but significantly reduce the flexibility of CDR H3 in the bound and unbound state of SM5-1 through intramolecular side chain interactions. Thus, these residues most likely alleviate unfavorable binding entropies associated with extra-long CDR H3s, and this might represent a common strategy during antibody maturation. Models of entire HCMV gB in different conformational states hint that SM5-1 neutralizes HCMV either by blocking the pre- to postfusion transition of gB or by precluding the interaction with additional effectors such as the gH/gL complex.
EVALuna2:8231

Structural characterization of intracellular C-terminal domains of group III metabotropic glutamate receptors. - Seebahn, Angela; Dinkel, Holger; Mohrlüder, J.; Hartmann, Rainer; Vogel, N.; Becker, Cord-Michael; Sticht, Heinrich; Enz, Ralf (Febs Letters, 2011)
Metabotropic glutamate receptors (mGluRs) are regulated by interacting proteins that mostly bind to their intracellular C-termini. Here, we investigated if mGluR6, mGluR7a and mGluR8a C-termini form predefined binding surfaces or if they were rather unstructured. Limited tryptic digest of purified peptides argued against the formation of stable globular folds. Circular dichroism, 1H NMR and 1H 15N HSQC spectra indicated the absence of rigid secondary structure elements. Furthermore, we localized short linear binding motifs in the unstructured receptor domains. Our data provide evidence that protein interactions of the analyzed mGluR C-termini are mediated rather by short linear motifs than by preformed folds. © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
UnivIS-Import:2015-04-14:Pub.2011.med.IB.profes_1.struct
Keywords: G-protein coupled receptor; Metabotropic glutamate receptor; Neurotransmitter receptor; Short linear motif

Structural insight into the giant Ca²?-binding adhesin SiiE: implications for the adhesion of Salmonella enterica to polarized epithelial cells - Grießl, Martin; Schmid, Benedikt; Kaßler, Kristin; Braunsmann, Christoph; Ritter, Regina; Barlag, Britta; Stierhof, York-Dieter; Sturm, Karina U.; Danzer, Claudia Agnes; Wagner, Carolin; Schaeffer, Tilman E.; Sticht, Heinrich; et al. (Structure, 2013)
SiiE from Salmonella enterica is a giant 5,559-residue-long nonfimbrial adhesin that is secreted by a type 1 secretion system (T1SS) and initiates bacterial adhesion to polarized host cells. Structural insight has been gained into the 53 bacterial Ig-like (BIg) domains of SiiE, which account for 94% of the entire SiiE sequence. The crystal structure of a fragment comprising BIg domains 50 to 52 of SiiE reveals the BIg domain architecture and highlights two types of SiiE-specific Ca²?-binding sites. Sequence homology considerations suggest that full-length SiiE interacts with more than 100 Ca²? ions. Molecular dynamics simulations and single-molecule imaging indicate that Ca²? binding confers SiiE with a rigid 200 nm rod-like habitus that is required to reach out beyond the Salmonella lipopolysaccharide layer and to promote adhesion to host cells. The crystal structure suggests plausible routes for the establishment of the initial contact between Salmonella and host cells.
EVALuna2:7643

Structural requirements for DNA binding of GCM proteins - Wegner, Michael; et al. (Nucleic Acids Research, 1998)
Members of the GCM family of transcription factors contain a DNA binding domain unrelated to any other known DNA binding domain and bind to a DNA sequence motif not recognized by any other known transcription factor. Here we show that positions 2, 3, 6 and 7 of the 5'-ATGCGGGT-3' motif are particularly important for DNA binding and that methylation of several G residues on the upper strand, but not on the lower strand, interfered with binding of GCM proteins. No differences were detected between the DNA binding of Drosophila GCM and mammalian mGCMa. Alanine scan mutagenesis of the DNA binding domain of mGCMa identified the three conserved amino acids K74, C76 and C125 as being essential for DNA binding. Conserved cysteine residues were also found to be important for maintaining the overall integrity of the DNA binding domain and for mediating redox sensitivity of DNA binding. These cysteine residues are arranged in a symmetrical structure that bears no resemblance to other cysteine-containing structures, such as zinc fingers. In agreement with this, DNA binding of mGCMa was not dependent on zinc ions. Our results give insights into the exact nature of the GCM binding sites expected in target genes and point to a role for redox regulation in the function of GCM proteins.
UnivIS-Import:2015-03-05:Pub.1998.med.IB.LPCIPDBI.struct

Structure-based functional analysis of effector protein SifA in living cells reveals motifs important for Salmonella intracellular proliferation - Namakchian, Mahsa; Kaßler, Kristin; Sticht, Heinrich; Hensel, Michael; Deiwick, Joerg (International Journal of Medical Microbiology, 2018)
The facultative intracellular pathogen Salmonella enterica survives and replicates inside the Salmonella-containing vacuole (SCV) of mammalian host cells. SifA is a key effector protein translocated by a type III secretion system and involved in formation of Salmonella-induced filaments (SIF), extensive tubular endosomal compartments. Recruitment of LAMP1 (lysosomal-associated membrane protein 1)-positive membranes to SIF ensures integrity and dynamics of the membrane network. The binding of SifA to the host protein SKIP (SifA and kinesin interacting protein) was proposed as crucial for this function. Due to structural mimicry SifA has further been proposed to interact with G-proteins. We conducted a mutational study of SifA to identify domains and amino acid residues specifically relevant for intracellular replication and SIF formation. Mutations were designed based on the available structural data of SifA and its interface with SKIP, or modeled for SifA as putative guanine nucleotide exchange factor. We developed a live cell imaging-based approach for volume quantification of the SIF network that allowed determination of subtle changes in SIF network and performed a comprehensive analysis of mutant forms of SifA by this approach. We found that the SifA catalytic loop of WxxxE effectors is as important for SIF formation and intracellular proliferation as the SKIP interaction motif, or the CAAX motif for membrane anchoring of SifA.
EVALuna2:35496

Structure of metabotropic glutamate receptor C-terminal domains in contact with interacting proteins - Enz, Ralf (Frontiers in Molecular Neuroscience, 2012)
Metabotropic glutamate receptors (mGluRs) regulate intracellular signal pathways that control several physiological tasks, including neuronal excitability, learning, and memory. This is achieved by the formation of synaptic signal complexes, in which mGluRs assemble with functionally related proteins such as enzymes, scaffolds, and cytoskeletal anchor proteins. Thus, mGluR associated proteins actively participate in the regulation of glutamatergic neurotransmission. Importantly, dysfunction of mGluRs and interacting proteins may lead to impaired signal transduction and finally result in neurological disorders, e.g., night blindness, addiction, epilepsy, schizophrenia, autism spectrum disorders and Parkinson's disease. In contrast to solved crystal structures of extracellular N-terminal domains of some mGluR types, only a few studies analyzed the conformation of intracellular receptor domains. Intracellular C-termini of most mGluR types are subject to alternative splicing and can be further modified by phosphorylation and SUMOylation. In this way, diverse interaction sites for intracellular proteins that bind to and regulate the glutamate receptors are generated. Indeed, most of the known mGluR binding partners interact with the receptors' C-terminal domains. Within the last years, different laboratories analyzed the structure of these domains and described the geometry of the contact surface between mGluR C-termini and interacting proteins. Here, I will review recent progress in the structure characterization of mGluR C-termini and provide an up-to-date summary of the geometry of these domains in contact with binding partners.
EVALuna2:4691

Structure of the GCM domain-DNA complex: a DNA-binding domain with a novel fold and mode of target site recognition - Wegner, Michael; Hashemolhosseini, Said; et al. (EMBO Journal, 2003)
Glia cell missing (GCM) transcription factors form a small family of transcriptional regulators in metazoans. The prototypical Drosophila GCM protein directs the differentiation of neuron precursor cells into glia cells, whereas mammalian GCM proteins are involved in placenta and parathyroid development. GCM proteins share a highly conserved 150 amino acid residue region responsible for DNA binding, known as the GCM domain. Here we present the crystal structure of the GCM domain from murine GCM bound to its octameric DNA target site at 2.85 Å resolution. The GCM domain exhibits a novel fold consisting of two domains tethered together by one of two structural Zn ions. We observe the novel use of a β-sheet in DNA recognition, whereby a five-stranded β-sheet protrudes into the major groove perpendicular to the DNA axis. The structure combined with mutational analysis of the target site and of DNA-contacting residues provides insight into DNA recognition by this new type of Zn-containing DNA-binding domain.
UnivIS-Import:2015-03-09:Pub.2003.med.IB.LPCIPDBI.struct
Keywords: DNA recognition; Glia cells; Transcription factor; X-ray crystal structure; Zn-binding

Studying protein function and the role of altered protein expression by antibody interference and three-dimensional reconstructions - Derlig, Kristin; Gießl, Andreas; Brandstätter, Johann Helmut; Enz, Ralf; Dahlhaus, Regina (Journal of Visualized Experiments, 2016)
A strict management of protein expression is not only essential to every organism alive, but also an important strategy to investigate protein functions in cellular models. Therefore, recent research invented different tools to target protein expression in mammalian cell lines or even animal models, including RNA and antibody interference. While the first strategy has gathered much attention during the past two decades, peptides mediating a translocation of antibody cargos across cellular membranes and into cells, obtained much less interest. In this publication, we provide a detailed protocol how to utilize a peptide carrier named Chariot in human embryonic kidney cells as well as in primary hippocampal neurons to perform antibody interference experiments and further illustrate the application of three-dimensional reconstructions in analyzing protein function. Our findings suggest that Chariot is, probably due to its nuclear localization signal, particularly well-suited to target proteins residing in the soma and the nucleus. Remarkably, when applying Chariot to primary hippocampal cultures, the reagent turned out to be surprisingly well accepted by dissociated neurons.
EVALuna2:4743
Keywords: Active motif; Antibody interference; Bioengineering; Issue 110; Nuclear proteins; Primary hippocampal cultures; Protein expression; Three-dimensional reconstructions

Substantial DNA methylation differences between two major neuronal subtypes in human brain - Kozlenkov, Alexey; Wang, Minghui; Roussos, Panos; Rudchenko, Sergei; Barbu, Mihaela; Bibikova, Marina; Klotzle, Brandy; Dwork, Andrew J.; Zhang, Bin; Hurd, Yasmin L.; Koonin, Eugene V.; Wegner, Michael; et al. (Nucleic Acids Research, 2016)
The brain is built from a large number of cell types which have been historically classified using location, morphology and molecular markers. Recent research suggests an important role of epigenetics in shaping and maintaining cell identity in the brain. To elucidate the role of DNA methylation in neuronal differentiation, we developed a new protocol for separation of nuclei from the two major populations of human prefrontal cortex neurons–GABAergic interneurons and glutamatergic (GLU) projection neurons. Major differences between the neuronal subtypes were revealed in CpG, non-CpG and hydroxymethylation (hCpG). A dramatically greater number of undermethylated CpG sites in GLU versus GABA neurons were identified. These differences did not directly translate into differences in gene expression and did not stem from the differences in hCpG methylation, as more hCpG methylation was detected in GLU versus GABA neurons. Notably, a comparable number of undermethylated non-CpG sites were identified in GLU and GABA neurons, and non-CpG methylation was a better predictor of subtype-specific gene expression compared to CpG methylation. Regions that are differentially methylated in GABA and GLU neurons were significantly enriched for schizophrenia risk loci. Collectively, our findings suggest that functional differences between neuronal subtypes are linked to their epigenetic specification.
EVALuna2:4988

Substrate-integrated microfluidics for sensitive biosensing with complementary THz metamaterials in water - Weisenstein, Christian; Richter, Merle; Wigger, Anna Katharina; Boßerhoff, Anja Katrin; Haring Bolivar, Peter (Applied Physics Letters, 2022)
Metamaterials can be utilized for a variety of applications and have emerged as a valuable tool in THz technologies. Used as THz biosensors, metasurfaces can significantly improve the sensitivity in the detection of biomolecules, but the high THz absorption of water represents a major challenge for the realization of a sensor for measurements in liquids. In this article, we propose an approach where the resonance feature of complementary asymmetric split ring resonators (CASRR) is maintained even for measurements in water, allowing highly sensitive detection of biomolecules in strongly absorbing liquids. This is enabled by the introduction of substrate-integrated microfluidics, which are shown to have a minimal effect on the transmission properties of the metamaterial. Due to this approach, the metamaterial structure design is independent from the microfluidic channels. Our simulations also show that the sensitivity of CASRR changes only marginally for lossless and highly absorbing materials. At the same time, the presented concept is easy to fabricate by standard lithography methods and can be applied to other metamaterial structures as well. (C) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
CRIS-Team WoS Importer:2022-02-11

Subunits of the epithelial sodium channel family are differentially expressed in the retina of mice with ocular hypertension. - Enz, Ralf; et al. (Journal of Neurochemistry, 2005)
Glaucoma is a prevalent cause of blindness, resulting in the apoptotic death of retinal ganglion cells and optic nerve degeneration. The disease is often associated with elevated intraocular pressure, however, molecular mechanisms involved in ganglion cell death are poorly understood. To identify proteins contributing to this pathological process, we analysed the retinal gene expression of DBA/2J mice that develop an elevated intraocular pressure by the age of 6 months with subsequent ganglion cell loss. In this study, we identified subunits of the epithelial sodium channel (ENaC) family that are specifically expressed under elevated intraocular pressure. Using reverse transcriptase polymerase chain reaction we observed a significant increase of α-ENaC in the neuronal retina of DBA/2J mice when compared with control animals, while β-ENaC and γ-ENaC were not detectable in this tissue. Specific immune sera to ENaC subunits showed up-regulation of α-ENaC in synaptic and nuclear layers of the retina, and in the retinal pigment epithelium. Consistent with our polymerase chain reaction data, β-ENaC was not detected by specific antibodies in the retina, while γ-ENaC was only present in the retinal pigment epithelium under ocular hypertension. Finally, the increase of α-ENaC gene expression in the neuronal retina and the retinal pigment epithelium was not observed in other tissues of DBA/2J mice. Since the intraocular pressure is regulated by the transport of aqueous humour across epithelial structures of the eye that in turn is associated with ion flux, the specific up-regulation of ENaC proteins could serve as a protecting mechanism against elevated intraocular pressure. © 2005 International Society for Neurochemistry.
UnivIS-Import:2017-12-18:Pub.2005.med.IB.profes_1.subuni
Keywords: ENaC; Gene expression; Glaucoma; Intraocular pressure; Retina

Sumo E3 ligases are expressed in the retina and regulate sumoylation of the metabotropic glutamate receptor 8b. - Duetting, Eva; Schroeder-Kress, Nadja; Sticht, Heinrich; Enz, Ralf (Biochemical Journal, 2011)
The central nervous system regulates neuronal excitability by macromolecular signalling complexes that consist of functionally related proteins, including neurotransmitter receptors, enzymes and scaffolds. The composition of these signal complexes is regulated by post-translational modifications, such as phosphorylation and SUMOylation (SUMO is small ubiquitin-related modifier). In the present study, we searched for proteins interacting with the intracellular C-termini of the metabotropic glutamate receptors mGluR8a and mGluR8b and identified proteins of the SUMOylation and NEDDylation machinery. The SUMO E3 ligases Pias1 [Pias is protein inhibitor of activated STAT (signal transducer and activator of transcription)] and Pias3L interacted strongly with mGluR8b, and were co-localized with the E2-conjugating Ubc9, SUMO1 and mGluR8b in cell bodies present in the ganglion cell layer of the mammalian retina. SUMO1 conjugation of Lys 882, present in a bona fide consensus sequence for SUMOylation (VKSE) in the mGluR8b C-terminus, was enhanced by addition of Pias1, consistent with an interaction between both proteins. Mutation of Lys 882 to arginine reduced, but did not abolish, mGluR8b SUMOylation. Co-mutating a second lysine residue (Lys 903) located in the mGluR8b isoform-specific C-terminus largely prevented SUMO1 conjugation by Ubc9. Modelling studies suggested that Lys 903 contacts Ubc9 and thus is part of the non-canonical SUMOylation site VKSG. In summary, the results of the present study show in vivo SUMOylation of the complete mGluR8b and co-localize proteins of the SUMOylation machinery in the retina. © The Authors Journal compilation © 2011 Biochemical Society.
UnivIS-Import:2015-04-14:Pub.2011.med.IB.profes_1.sumoe3
Keywords: G-protein-coupled receptor (GPCR); Metabotropic glutamate receptor (mGluR); Protein inhibitor of activated STAT (signal transducer and activator of transcription) 1 (Pias1); Retina

Suppressive effects of tumor cell-derived 5'-deoxy-5'-methylthioadenosine on human T cells - Henrich, Frederik; Singer, Katrin; Poller, Kerstin; Bernhardt, Luise; Strobl, Carolin; Limm, Katharina; Ritter, Axel P.; Gottfried, Eva; Voelkl, Simon; Jacobs, Benedikt; Peter, Katrin; Mougiakakos, Dimitrios; et al. (OncoImmunology, 2016)
The immunosuppressive tumor microenvironment represents one of the main obstacles for immunotherapy of cancer. The tumor milieu is among others shaped by tumor metabolites such as 5'-deoxy-5'-methylthioadenosine (MTA). Increased intratumoral MTA levels result from a lack of the MTA-catabolizing enzyme methylthioadenosine phosphorylase (MTAP) in tumor cells and are found in various tumor entities. Here, we demonstrate that MTA suppresses proliferation, activation, differentiation, and effector function of antigen-specific T cells without eliciting cell death. Conversely, if MTA is added to highly activated T cells, MTA exerts cytotoxic effects on T cells. We identified the Akt pathway, a critical signal pathway for T cell activation, as a target of MTA, while, for example, p38 remained unaffected. Next, we provide evidence that MTA exerts its immunosuppressive effects by interfering with protein methylation in T cells. To confirm the relevance of the suppressive effects of exogenously added MTA on human T cells, we used an MTAP-deficient tumor cell-line that was stably transfected with the MTAP-coding sequence. We observed that T cells stimulated with MTAP-transfected tumor cells revealed a higher proliferative capacity compared to T cells stimulated with Mock-transfected cells. In conclusion, our findings reveal a novel immune evasion strategy of human tumor cells that could be of interest for therapeutic targeting.
EVALuna2:4745

Survival and glial fate acquisition of neural crest cells are regulated by an interplay between the transcription factor Sox10 and extrinsic combinatorial signaling - Wegner, Michael; et al. (Development, 2001)
The transcription factor Sox10 is required for proper development of various neural crest-derived cell types. Several lineages including melanocytes, autonomic and enteric neurons, and all subtypes of peripheral glia are missing in mice homozygous for Sox10 mutations. Moreover, haploinsufficiency of Sox10 results in neural crest defects that cause Waardenburg/Hirschsprung disease in humans. We provide evidence that the cellular basis to these phenotypes is likely to be a requirement for Sox10 by neural crest stem cells before lineage segregation. Cell death is increased in undifferentiated, postmigratory neural crest cells that lack Sox10, suggesting a role of Sox10 in the survival of neural crest cells. This function is mediated by neuregulin, which acts as a survival signal for postmigratory neural crest cells in a Sox10-dependent manner. Furthermore, Sox10 is required for glial fate acquisition, as the surviving mutant neural crest cells are unable to adopt a glial fate when challenged with different gliogenic conditions. In Sox10 heterozygous mutant neural crest cells, survival appears to be normal, while fate specifications are drastically affected. Thereby, the fate chosen by a mutant neural crest cell is context dependent. Our data indicate that combinatorial signaling by Sox10, extracellular factors such as neuregulin 1, and local cell-cell interactions is involved in fine-tuning lineage decisions by neural crest stem cells. Failures in fate decision processes might thus contribute to the etiology of Waardenburg/Hirschsprung disease.
UnivIS-Import:2015-03-09:Pub.2001.med.IB.LPCIPDBI.cellul
Keywords: Community effects; Gliogenesis; Mouse; Neural crest; Sox10; Waardenburg/Hirschsprung disease

Sweet but dangerous - the role of immunoglobulin G glycosylation in autoimmunity and inflammation - Biermann, Mona; Griffante, G.; Podolska, Malgorzata; Boeltz, Sebastian; Stürmer, Jörg; Munoz, Luis Enrique; Bilyy, R.; Herrmann, Martin; Munoz Becerra, Luis (Lupus, 2016)
Glycosylation is well-known to modulate the functional capabilities of immunoglobulin G (IgG)-mediated cellular and humoral responses. Indeed, highly sialylated and desialylated IgG is endowed with anti- and pro-inflammatory activities, respectively, whereas fully deglycosylated IgG is a rather lame duck, with no effector function besides toxin neutralization. Recently, several studies revealed the impact of different glycosylation patterns on the Fc part and Fab fragment of IgG in several autoimmune diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Here, we provide a synoptic update summarizing the most important aspects of antibody glycosylation, and the current progress in this field. We also discuss the therapeutic options generated by the modification of the glycosylation of IgG in a potential treatment for chronic inflammatory diseases.
EVALuna2:13284

Switchable Signaling Molecules for Media Modulation: Fundamentals, Applications, and Research Directions - Brand, Lukas; Scherer, Maike; Lotter, Sebastian; tom Dieck, Teena; Schaufer, Maximilian; Burkovski, Andreas; Sticht, Heinrich; Castiglione, Kathrin; Schober, Robert (IEEE Communications Magazine, 2023)
Although visionary applications of molecular communication (MC), such as long-term continuous health monitoring by cooperative in-body nanomachines, have been proposed, MC is still in its infancy when it comes to practical implementation. In particular, long-term experiments and applications face issues such as depletion of signaling molecules (SMs) at the transmitter (TX) and inter-symbol interference (ISI) at the receiver (RX). To overcome these practical challenges, a new class of SMs with switchable states seems to be promising for future MC applications. In this work, we provide an overview of existing switchable SMs, and classify them according to their properties. Furthermore, we highlight how switchable SMs can be utilized as information carriers for media modulation. In addition, we present theoretical and experimental results for an end-toend MC system employing the green fluorescent protein variant "Dreiklang" (GFPD) as switchable SM. Our experimental results show, for the first time, successful information transmission in a closed-loop pipe system using media modulation. Finally, we discuss media modulation specific challenges and opportunities.
Created from Fastlane, Scopus look-up
Keywords: Information processing; Media; Modulation; Monitoring; Optical switches; Optical transmitters; Proteins

Synergic Functions of miRNAs Determine Neuronal Fate of Adult Neural Stem Cells - Pons-Espinal, Meritxell; De Luca, Emanuela; Marzi, Matteo Jacopo; Beckervordersandforth, Ruth; Armirotti, Andrea; Nicassio, Francesco; Fabel, Klaus; Kempermann, Gerd; Tonelli, Davide De Pietri (Stem Cell Reports, 2017)
Adult neurogenesis requires the precise control of neuronal versus astrocyte lineage determination in neural stem cells. While microRNAs (miRNAs) are critically involved in this step during development, their actions in adult hippocampal neural stem cells (aNSCs) has been unclear. As entry point to address that question we chose DICER, an endoribonuclease essential for miRNA biogenesis and other RNAi-related processes. By specific ablation of Dicer in aNSCs in vivo and in vitro, we demonstrate that miRNAs are required for the generation of new neurons, but not astrocytes, in the adult murine hippocampus. Moreover, we identify 11 miRNAs, of which 9 have not been previously characterized in neurogenesis, that determine neurogenic lineage fate choice of aNSCs at the expense of astrogliogenesis. Finally, we propose that the 11 miRNAs sustain adult hippocampal neurogenesis through synergistic modulation of 26 putative targets from different pathways.
EVALuna2:4761

Synthetic Peptides as Protein Mimics - Groß, Andrea; Hashimoto, Chie; Sticht, Heinrich; Eichler, Jutta (Frontiers in Bioengineering and Biotechnology, 2015)
The design and generation of molecules capable of mimicking the binding and/or functional sites of proteins represents a promising strategy for the exploration and modulation of protein function through controlled interference with the underlying molecular interactions. Synthetic peptides have proven an excellent type of molecule for the mimicry of protein sites because such peptides can be generated as exact copies of protein fragments, as well as in diverse chemical modifications, which includes the incorporation of a large range of non-proteinogenic amino acids as well as the modification of the peptide backbone. Apart from extending the chemical and structural diversity presented by peptides, such modifications also increase the proteolytic stability of the molecules, enhancing their utility for biological applications. This article reviews recent advances by this and other laboratories in the use of synthetic protein mimics to modulate protein function, as well as to provide building blocks for synthetic biology.
EVALuna2:26297

?-Synuclein impairs oligodendrocyte progenitor maturation in multiple system atrophy - May, Verena Elisabeth Luise; Ettle, Benjamin; Pöhler, Anne-Maria; Nuber, Silke; Ubhi, Kiren; Rockenstein, Edward; Winner, Beate; Wegner, Michael; Masliah, Eliezer; Winkler, Jürgen (Neurobiology of Aging, 2014)
Multiple system atrophy (MSA), an atypical parkinsonian disorder, is characterized by ?-synuclein (?-syn(+)) cytoplasmatic inclusions in mature oligodendrocytes. Oligodendrocyte progenitor cells (OPCs) represent a distinct cell population with the potential to replace dysfunctional oligodendrocytes. However, the role of OPCs in MSA and their potential to replace mature oligodendrocytes is still unclear. A postmortem analysis in MSA patients revealed ?-syn within OPCs and an increased number of striatal OPCs. In an MSA mouse model, an age-dependent increase of dividing OPCs within the striatum and the cortex was detected. Despite of myelin loss, there was no reduction of mature oligodendrocytes in the corpus callosum or the striatum. Dissecting the underlying molecular mechanisms an oligodendroglial cell line expressing human ?-syn revealed that ?-syn delays OPC maturation by severely downregulating myelin-gene regulatory factor and myelin basic protein. Brain-derived neurotrophic factor was reduced in MSA models and its in vitro supplementation partially restored the phenotype. Taken together, efficacious induction of OPC maturation may open the window to restore glial and neuronal function in MSA.
EVALuna2:4963

?-Synuclein-induced myelination deficit defines a novel interventional target for multiple system atrophy - Ettle, Benjamin; Kerman, Bilal E.; Valera, Elvira; Gillmann, Clarissa; Schlachetzki, Johannes; Reiprich, Simone; Büttner, Christian; Ekici, Arif Bülent; Reis, André; Wegner, Michael; Bäuerle, Tobias; Riemenschneider, Markus J.; et al. (Acta Neuropathologica, 2016)
Multiple system atrophy (MSA) is a rare atypical parkinsonian disorder characterized by a rapidly progressing clinical course and at present without any efficient therapy. Neuropathologically, myelin loss and neurodegeneration are associated with ?-synuclein accumulation in oligodendrocytes, but underlying pathomechanisms are poorly understood. Here, we analyzed the impact of oligodendrocytic ?-synuclein on the formation of myelin sheaths to define a potential interventional target for MSA. Post-mortem analyses of MSA patients and controls were performed to quantify myelin and oligodendrocyte numbers. As pre-clinical models, we used transgenic MSA mice, a myelinating stem cell-derived oligodendrocyte-neuron co-culture, and primary oligodendrocytes to determine functional consequences of oligodendrocytic ?-synuclein overexpression on myelination. We detected myelin loss accompanied by preserved or even increased numbers of oligodendrocytes in post-mortem MSA brains or transgenic mouse forebrains, respectively, indicating an oligodendrocytic dysfunction in myelin formation. Corroborating this observation, overexpression of ?-synuclein in primary and stem cell-derived oligodendrocytes severely impaired myelin formation, defining a novel ?-synuclein-linked pathomechanism in MSA. We used the pro-myelinating activity of the muscarinic acetylcholine receptor antagonist benztropine to analyze the reversibility of the myelination deficit. Transcriptome profiling of primary pre-myelinating oligodendrocytes demonstrated that benztropine readjusts myelination-related processes such as cholesterol and membrane biogenesis, being compromised by oligodendrocytic ?-synuclein. Additionally, benztropine restored the ?-synuclein-induced myelination deficit of stem cell-derived oligodendrocytes. Strikingly, benztropine also ameliorated the myelin deficit in transgenic MSA mice, resulting in a prevention of neuronal cell loss. In conclusion, this study defines the ?-synuclein-induced myelination deficit as a novel and crucial pathomechanism in MSA. Importantly, the reversible nature of this oligodendrocytic dysfunction opens a novel avenue for an intervention in MSA.
EVALuna2:4991

Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of East Asian-type Helicobacter pylori strains - Lind, Judith; Backert, Steffen; Hoffmann, Rebecca; Eichler, Jutta; Yamaoka, Yoshio; Perez-Perez, Guillermo I.; Torres, Javier; Sticht, Heinrich; Tegtmeyer, Nicole (BMC Microbiology, 2016)
Highly virulent strains of the gastric pathogen Helicobacter pylori encode a type IV secretion system (T4SS) that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation by members of the oncogenic c-Src and c-Abl host kinases at EPIYA-sequence motifs A, B and D in East Asian-type strains. These phosphorylated EPIYA-motifs serve as recognition sites for various SH2-domains containing human proteins, mediating interactions of CagA with host signaling factors to manipulate signal transduction pathways. Recognition of phospho-CagA is mainly based on the use of commercial pan-phosphotyrosine antibodies that were originally designed to detect phosphotyrosines in mammalian proteins. Specific anti-phospho-EPIYA antibodies for each of the three sites in CagA are not forthcoming.This study was designed to systematically analyze the detection preferences of each phosphorylated East Asian CagA EPIYA-motif by pan-phosphotyrosine antibodies and to determine a minimal recognition sequence. We synthesized phospho- and non-phosphopeptides derived from each predominant EPIYA-site, and determined the recognition patterns by seven different pan-phosphotyrosine antibodies using Western blotting, and also investigated representative East Asian H. pylori isolates during infection. The results indicate that a total of only 9-11 amino acids containing the phosphorylated East Asian EPIYA-types are required and sufficient to detect the phosphopeptides with high specificity. However, the sequence recognition by the different antibodies was found to bear high variability. From the seven antibodies used, only four recognized all three phosphorylated EPIYA-motifs A, B and D similarly well. Two of the phosphotyrosine antibodies preferentially bound primarily to the phosphorylated motif A and D, while the seventh antibody failed to react with any of the phosphorylated EPIYA-motifs. Control experiments confirmed that none of the antibodies reacted with non-phospho-CagA peptides and in accordance were able to recognize phosphotyrosine proteins in human cells.The results of this study disclose the various binding preferences of commercial anti-phosphotyrosine antibodies for phospho-EPIYA-motifs, and are valuable in the application for further characterization of CagA phosphorylation events during infection with H. pylori and risk prediction for gastric disease development.
EVALuna2:26300
Keywords: c-Abl; c-Src; CagA; cagPAI; Dotblot; EPIYA motifs; Gastric cancer; Helicobacter pylori; Signaling; Type IV secretion; T4SS; Tyrosine kinases

Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of Western-type Helicobacter pylori strains - Lind, Judith; Backert, Steffen; Pfleiderer, Klaus; Berg, Douglas E.; Yamaoka, Yoshio; Sticht, Heinrich; Tegtmeyer, Nicole (PLoS ONE, 2014)
The clinical outcome of Helicobacter pylori infections is determined by multiple host-pathogen interactions that may develop to chronic gastritis, and sometimes peptic ulcers or gastric cancer. Highly virulent strains encode a type IV secretion system (T4SS) that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation at EPIYA-sequence motifs, called A, B and C in Western-type strains, by members of the oncogenic Src and Abl host kinases. Phosphorylated EPIYA-motifs mediate interactions of CagA with host signaling factors–in particular various SH2-domain containing human proteins–thereby hijacking multiple downstream signaling cascades. Observations of tyrosine-phosphorylated CagA are mainly based on the use of commercial phosphotyrosine antibodies, which originally were selected to detect phosphotyrosines in mammalian proteins. Systematic studies of phosphorylated EPIYA-motif detection by the different antibodies would be very useful, but are not yet available. To address this issue, we synthesized phospho- and non-phosphopeptides representing each predominant Western CagA EPIYA-motif, and determined the recognition patterns of seven different phosphotyrosine antibodies in Western blots, and also performed infection studies with diverse representative Western H. pylori strains. Our results show that a total of 9-11 amino acids containing the phosphorylated EPIYA-motifs are necessary and sufficient for specific detection by these antibodies, but revealed great variability in sequence recognition. Three of the antibodies recognized phosphorylated EPIYA-motifs A, B and C similarly well; whereas preferential binding to phosphorylated motif A and motifs A and C was found with two and one antibodies, respectively, and the seventh anti-phosphotyrosine antibody did not recognize any phosphorylated EPIYA-motif. Controls showed that none of the antibodies recognized the corresponding non-phospho CagA peptides, and that all of them recognized phosphotyrosines in mammalian proteins. These data are valuable in judicious application of commercial anti-phosphotyrosine antibodies and in characterization of CagA phosphorylation during infection and disease development.
EVALuna2:26284

Systematic Investigation of CMTM Family Genes Suggests Relevance to Glioblastoma Pathogenesis and CMTM1 and CMTM3 as Priority Targets - Delic, Sabit; Thuy, Andreas; Schulze, Markus; Proescholdt, Martin A.; Dietrich, Peter; Boßerhoff, Anja Katrin; Riemenschneider, Markus J. (Genes Chromosomes & Cancer, 2015)
The novel CKLF-like Marvel Transmembrane Domain-containing gene family (CMTM) consists of 8 members (CMTM1-8). As little is known about the oncogenic impact of these genes, we aimed to systematically investigate the relevance of CMTMs to glioblastoma pathogenesis. We performed mRNA expression analyses and survival correlations in glioblastoma patients. Moreover, we analyzed the impact of RNAi-based silencing and overexpression of CMTM family genes on tumor cell proliferation and invasion in vitro. CMTMs appeared to be widely regulated in the group of glioblastomas relative to non-neoplastic brain (NB) tissue (significant upregulation for CMTM2, 3, and 6 and significant downregulation for CMTM 4 and 8). For CMTM1, 5 and 7, we found aberrant expression levels in individual tumors. Functionally, CMTM1, 3, and 7 promoted tumor cell invasion, while CMTM1 additionally enhanced cell proliferation. In a large clinically annotated dataset, higher CMTM1 and 3 expression was significantly correlated with shorter overall survival. Our data thus suggest CMTM1 and 3 as priority targets in glioblastomas. Using a human phosphokinase protein expression profiling assay, we can provide first insights into signalling of these two genes that might be conveyed by growth factor receptor, Src family kinase and WNT activation.
CRIS-Team Scopus Importer:2022-08-05

T4SS-dependent TLR5 activation by Helicobacter pylori infection - Suneesh Kumar, Pachathundikandi; Tegtmeyer, Nicole; Arnold, Isabelle Catherine; Lind, Judith; Neddermann, Matthias; Falkeis-Veits, Christina; Chattopadhyay, Sujay; Brönstrup, Mark; Tegge, Werner; Hong, Minsun; Sticht, Heinrich; Müller, Anne; et al. (Nature Communications, 2019)
Toll-like receptor TLR5 recognizes a conserved domain, termed D1, that is present in flagellins of several pathogenic bacteria but not in Helicobacter pylori. Highly virulent H. pylori strains possess a type IV secretion system (T4SS) for delivery of virulence factors into gastric epithelial cells. Here, we show that one of the H. pylori T4SS components, protein CagL, can act as a flagellin-independent TLR5 activator. CagL contains a D1-like motif that mediates adherence to TLR5+ epithelial cells, TLR5 activation, and downstream signaling in vitro. TLR5 expression is associated with H. pylori infection and gastric lesions in human biopsies. Using Tlr5-knockout and wild-type mice, we show that TLR5 is important for efficient control of H. pylori infection. Our results indicate that CagL, by activating TLR5, may modulate immune responses to H. pylori.
CRIS-Team Scopus Importer:2019-12-27

Targeted deletion of Sox10 by Wnt1-cre defects: neuronal migration and projection in the mouse inner ear. - Reiprich, Simone; Wegner, Michael; et al. (PLoS ONE, 2014)
UnivIS-Import:2018-09-05:Pub.2014.med.IB.LPCIPDBI.target

Targeted Therapy-Resistant Melanoma Cells Acquire Transcriptomic Similarities with Human Melanoblasts - Larribere, Lionel; Kuphal, Silke; Sachpekidis, Christos; Hueser, Laura; Boßerhoff, Anja Katrin; Utikal, Jochen (Cancers, 2018)
The mechanisms of adaptive and acquired drug resistance in tumors are not completely understood. So far, gene amplifications or mutations, leading to the reactivation of the MAPK or PI3K pathways have been described. In this study, we used two different methods to generate human melanoblasts: (1) via differentiation from induced pluripotent stem cells (iPSCs) and (2) via dedifferentiation from melanocytes. The melanoblast transcriptomes were then compared to the transcriptome of MAPK inhibitor-resistant melanoma cells. We observed that the expression of genes associated with cell cycle control, DNA damage control, metabolism, and cancer was altered in both melanoblast populations and in both adaptive and acquired resistant melanoma samples, compared to drug-sensitive samples. However, genes involved in antigen presentation and cellular movement were only regulated in the melanoblast populations and in the acquired resistant melanoma samples, compared to the drug-sensitive samples. Moreover, melanocyte-derived melanoblasts and adaptive resistant melanoma samples were characterized by different expression levels of certain transcription factors or genes involved in the CDK5 pathway. In conclusion, we show here that in vitro models of human melanoblasts are very important tools to comprehend the expression profiles of drug-resistant melanoma.
EVALuna2:202903

Targeting zonulin and intestinal epithelial barrier function to prevent onset of arthritis - Tajik, Narges; Frech, Michael; Schulz, Oscar; Schälter, Fabian; Lucas, Sébastien; Azizov, Vugar; Dürholz, Kerstin; Steffen, Franziska; Omata, Yasunori; Rings, Andreas; Bertog, Marko; Rizzo, Aroldo; et al. (Nature Communications, 2020)
Gut microbial dysbiosis is associated with the development of autoimmune disease, but the mechanisms by which microbial dysbiosis affects the transition from asymptomatic autoimmunity to inflammatory disease are incompletely characterized. Here, we identify intestinal barrier integrity as an important checkpoint in translating autoimmunity to inflammation. Zonulin family peptide (zonulin), a potent regulator for intestinal tight junctions, is highly expressed in autoimmune mice and humans and can be used to predict transition from autoimmunity to inflammatory arthritis. Increased serum zonulin levels are accompanied by a leaky intestinal barrier, dysbiosis and inflammation. Restoration of the intestinal barrier in the pre-phase of arthritis using butyrate or a cannabinoid type 1 receptor agonist inhibits the development of arthritis. Moreover, treatment with the zonulin antagonist larazotide acetate, which specifically increases intestinal barrier integrity, effectively reduces arthritis onset. These data identify a preventive approach for the onset of autoimmune disease by specifically targeting impaired intestinal barrier function.
CRIS-Team Scopus Importer:2020-05-05

Technologies in the Whole-Genome Age: MALDI-TOF-Based Genotyping - Humeny, Andreas; Vogel, Nicolas; Schiebel, Katrin (Transfusion Medicine and Hemotherapy, 2009)
With the decipherment of the human genome, new questions have moved into the focus of today's research. One key aspect represents the discovery of DNA variations capable to influence gene transcription, RNA splicing, or regulating processes, and their link to pathology. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) is a powerful tool for the qualitative investigation and relative quantification of variations like single nucleotide polymorphisms, DNA methylation, microsatellite instability, or loss of heterozygosity. After its introduction into proteomics, efforts were made to adopt this technique to DNA analysis. Initially intended for peptide/protein analysis, it held several difficulties for application to nucleic acids. Today, MALDI-TOF-MS has reached worldwide acceptance and application in nucleic acid research, with a wide spectrum of methods being available. One of the most versatile approaches relies on primer extension to genotype single alleles, microsatellite repeat lengths or the methylation status of a given cytosine. Optimized methods comprising intelligent primer design and proper nucleotide selection for primer extension enabled multiplexing of reactions, rendering the analysis more economic due to parallel genotyping of several alleles in a single experiment. Laboratories equipped with MALDI-TOF-MS possess a universal technical platform for the analysis of a large variety of different molecules.

Telomere shortening reduces Alzheimer's disease amyloid pathology in mice - Rolyan, Harshvardhan; Scheffold, Annika; Heinrich, Annette; Begus-Nahrmann, Yvonne; Langkopf, Britta Heike; Hoelter, Sabine M.; Vogt-Weisenhorn, Daniela M.; Liss, Birgit; Wurst, Wolfgang; Lie, Dieter Chichung; Thal, Dietmar Rudolf; Biber, Knut; et al. (Brain, 2011)
Alzheimer's disease is a neurodegenerative disorder of the elderly and advancing age is the major risk factor for Alzheimer's disease development. Telomere shortening represents one of the molecular causes of ageing that limits the proliferative capacity of cells, including neural stem cells. Studies on telomere lengths in patients with Alzheimer's disease have revealed contrary results and the functional role of telomere shortening on brain ageing and Alzheimer's disease is not known. Here, we have investigated the effects of telomere shortening on adult neurogenesis and Alzheimer's disease progression in mice. The study shows that aged telomerase knockout mice with short telomeres (G3Terc-/-) exhibit reduced dentate gyrus neurogenesis and loss of neurons in hippocampus and frontal cortex, associated with short-term memory deficit in comparison to mice with long telomere reserves (Terc+/+). In contrast, telomere shortening improved the spatial learning ability of ageing APP23 transgenic mice, a mouse model for Alzheimer's disease. Telomere shortening was also associated with an activation of microglia in ageing amyloid-free brain. However, in APP23 transgenic mice, telomere shortening reduced both amyloid plaque pathology and reactive microgliosis. Together, these results provide the first experimental evidence that telomere shortening, despite impairing adult neurogenesis and maintenance of post-mitotic neurons, can slow down the progression of amyloid plaque pathology in Alzheimer's disease, possibly involving telomere-dependent effects on microglia activation.
EVALuna2:26337

Temporal patterning of the vertebrate developing neural tube - Sagner, Andreas (Current Opinion in Genetics & Development, 2024)
The chronologically ordered generation of distinct cell types is essential for the establishment of neuronal diversity and the formation of neuronal circuits. Recently, single-cell transcriptomic analyses of various areas of the developing vertebrate nervous system have provided evidence for the existence of a shared temporal patterning program that partitions neurons based on the timing of neurogenesis. In this review, I summarize the findings that lead to the proposal of this shared temporal program before focusing on the developing spinal cord to discuss how temporal patterning in general and this program specifically contributes to the ordered formation of neuronal circuits.
CRIS-Team Scopus Importer:2024-03-22

Terminal differentiation of myelin-forming oligodendrocytes depends on the transcription factor Sox10 - Wegner, Michael; Stolt, Claus; et al. (Genes & Development, 2002)
Sox10 is a high-obility-group transcriptional regulator in early neural crest. Without Sox10, no glia develop throughout the peripheral nervous system. Here we show that Sox10 is restricted in the central nervous system to myelin-forming oligodendroglia. In Sox10-deficient mice progenitors develop, but terminal differentiation is disrupted. No myelin was generated upon transplantation of Sox10-deficient neural stem cells into wild-type hosts showing the permanent, cell-autonomous nature of the defect. Sox10 directly regulates myelin gene expression in oligodendrocytes, but does not control erbB3 expression as in peripheral glia. Sox10 thus functions in peripheral and central glia at different stages and through different mechanisms.
UnivIS-Import:2015-03-09:Pub.2002.med.IB.LPCIPDBI.termin
Keywords: Glial cells; HMG; MBP; Neuregulin; PLP; Sox

Testing Suitability of Cell Cultures for SILAC-Experiments Using SWATH-Mass Spectrometry - Reinders, Yvonne; Voeller, Daniel; Boßerhoff, Anja Katrin; Oefner, Peter J.; Reinders, Joerg (Methods in Molecular Biology, 2016)
Precise quantification is a major issue in contemporary proteomics. Both stable-isotope-labeling and label-free methods have been established for differential protein quantification and both approaches have different advantages and disadvantages. The present protocol uses the superior precision of label-free SWATH-mass spectrometry to test for suitability of cell lines for a SILAC-labeling approach as systematic regulations may be introduced upon incorporation of the "heavy" amino acids. The SILAC-labeled cell cultures can afterwards be used for further analyses where stable-isotope-labeling is mandatory or has substantial advantages over label-free approaches such as pulse-chase-experiments and differential protein interaction analyses based on co-immunoprecipitation. As SWATH-mass spectrometry avoids the missing-value-problem typically caused by undersampling in highly complex samples and shows superior precision for the quantification, it is better suited for the detection of systematic changes caused by the SILAC-labeling and thus, can serve as a useful tool to test cell lines for changes upon SILAC-labeling.
EVALuna2:4730

Testis cord differentiation after the sex determination stage is independent of Sox9 but fails in the combined absence of Sox9 and Sox8. - Wegner, Michael; et al. (Developmental Biology, 2009)
Sox9 and Sox8 are transcription factors expressed in embryonic and postnatal Sertoli cells of the mouse testis. Sox9 inactivation prior to the sex determination stage leads to complete XY sex reversal. In contrast, there is normal embryonic testis development in Sox8 mutants which are initially fertile, but later develop progressive seminiferous tubule failure and infertility. To determine whether Sox9 is required for testis development after the initial steps of sex determination, we crossed Sox9flox mice with an AMH-Cre transgenic line thereby completely deleting Sox9 in Sertoli cells by E14.0. Conditional Sox9 null mutants show normal embryonic testis development and are initially fertile, but, like Sox8-/- mutants, become sterile from dysfunctional spermatogenesis at about 5 months. To see whether Sox8 may compensate for the absence of Sox9 during embryonic testis differentiation, we generated a Sox9 conditional knockout on a Sox8 mutant background. In the double mutants, differentiation of testis cords into seminiferous testis tubules ceases after P6 in the absence of one Sox8 allele, and after P0 in the absence of both Sox8 alleles, leading to complete primary infertility. Sox9,Sox8 double nullizygous testes show upregulation of early ovary-specific markers and downregulation of Sertoli intercellular junctions at E15.5. Their very low Amh levels still cause complete regression of the Müllerian duct but with reduced penetrance. This study shows that testis cord differentiation is independent of Sox9, and that concerted Sox9 and Sox8 function in post E14.0 Sertoli cells is essential for the maintenance of testicular function. © 2008 Elsevier Inc. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.med.IB.LPCIPDBI.testis
Keywords: Amh; Mouse testis differentiation; Sox8; Sox9; Testis cords

Th17 Lymphocytes Induce Neuronal Cell Death in a Human iPSC-Based Model of Parkinson's Disease - Sommer, Annika; Marxreiter, Franz; Krach, Florian; Fadler, Tanja; Grosch, Janina; Maroni, Michele; Gräf, Daniela; Eberhardt, Esther; Riemenschneider, Markus J.; Yeo, Gene W.; Kohl, Zacharias; Xiang, Wei; et al. (Cell Stem Cell, 2019)
EVALuna2:203042

Th17 Lymphocytes Induce Neuronal Cell Death in a Human iPSC-Based Model of Parkinson's Disease - Sommer, Annika; Maxreiter, Franz; Krach, Florian; Fadler, Tanja; Grosch, Janina; Maroni, Michele; Graef, Daniela; Eberhardt, Esther; Riemenschneider, Markus J.; Yeo, Gene W.; Kohl, Zacharias; Xiang, Wei; et al. (Cell Stem Cell, 2018)
Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive degeneration of midbrain neurons (MBNs). Recent evidence suggests contribution of the adaptive immune system in PD. Here, we show a role for human T lymphocytes as cell death inducers of induced pluripotent stem cell (iPSC)-derived MBNs in sporadic PD. Higher Th17 frequencies were found in the blood of PD patients and increased numbers of T lymphocytes were detected in postmortem PD brain tissues. We modeled this finding using autologous co-cultures of activated T lymphocytes and iPSC-derived MBNs of sporadic PD patients and controls. After co-culture with T lymphocytes or the addition of IL-17, PD iPSC-derived MBNs underwent increased neuronal death driven by upregulation of IL-17 receptor (IL-17R) and NF kappa B activation. Blockage of IL-17 or IL-17R, or the addition of the FDA-approved anti-IL-17 antibody, secukinumab, rescued the neuronal death. Our findings indicate a critical role for IL-17-producing T lymphocytes in sporadic PD.
EVALuna2:35782

The actin-binding protein Filamin-A interacts with the metabotropic glutamate receptor type 7. - Enz, Ralf (FEBS letters, 2002)
A yeast two-hybrid screen identified Filamin-A as a binding partner of the metabotropic glutamate receptor type 7b (mGluR7b) splice variant. In addition, Filamin-A interacted with mGluR4a, mGluR5a, mGluR5b, mGluR7a and mGluR8a. Domain mapping revealed that alternative splicing of mGluR4, mGluR7 and mGluR8 C-termini regulated the interaction. A conserved tyrosine within mGluR C-termini was identified to mediate the binding to Filamin-A. Protein interactions were verified in biochemical assays using recombinant and native proteins. Finally, co-expression of Filamin-A and mGluR7 splice variants was shown in brain regions. These findings suggest that Filamin-A may physically link metabotropic glutamate receptors to the actin cytoskeleton. © 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.
UnivIS-Import:2017-12-18:Pub.2002.med.IB.profes_1.theact
Keywords: Expression pattern; Filamin-A; mGluR; Protein-protein interaction; Yeast two-hybrid

The anti-fibrotic effect of cold atmospheric plasma on localized scleroderma in vitro and in vivo - Arndt, Stephanie; Unger, Petra; Boßerhoff, Anja Katrin; Berneburg, Mark; Karrer, Sigrid (Biomedicines, 2021)
Cold Atmospheric Plasma (CAP) has shown promising results in the treatment of various skin diseases. The therapeutic effect of CAP on localized scleroderma (LS), however, has not yet been evaluated. We investigated the effects of CAP on LS by comparing human normal fibroblasts (hNF), human TGF-β-activated fibroblasts (hAF), and human localized scleroderma-derived fibroblasts (hLSF) after direct CAP treatment, co-cultured with plasma-treated human epidermal keratinocytes (hEK) and with an experimental murine model of scleroderma. In hAF and hLSF, 2 min CAP treatment with the MicroPlaSterβ® plasma torch did not affect pro-fibrotic gene expression of alpha smooth muscle actin, fibroblast activating protein, and collagen type I, however, it promoted re-expression of matrix metalloproteinase 1. Functionally, CAP treatment reduced cell migration and stress fiber formation in hAF and hLSF. The relevance of CAP treatment was confirmed in an in vivo model of bleomycin-induced dermal fibrosis. In this model, CAP-treated mice showed significantly reduced dermal thickness and collagen deposition as well as a decrease in both alpha smooth muscle actin-positive myofibroblasts and CD68-positive macrophages in the affected skin in comparison to untreated fibrotic tissue. In conclusion, this study provides the first evidence for the successful use of CAP for treating LS and may be the basis for clinical trials including patients with LS.
CRIS-Team Scopus Importer:2021-11-12
Keywords: Anti-fibrosis; Bleomycin-induced fibrosis; Cold atmospheric plasma; Localized scleroderma

The anti-fibrotic effect of cold atmospheric plasma on localized scleroderma in vitro and in vivo - Arndt, Stephanie; Unger, Petra; Boßerhoff, Anja Katrin; Berneburg, Mark; Karrer, Sigrid (EXPERIMENTAL DERMATOLOGY, 2022)
Cold Atmospheric Plasma (CAP) has shown promising results in the treatment of various skin diseases. The therapeutic effect of CAP on localized scleroderma (LS), however, has not yet been evaluated. We investigated the effects of CAP on LS by comparing human normal fibroblasts (hNF), human TGF-β-activated fibroblasts (hAF), and human localized scleroderma-derived fibroblasts (hLSF) after direct CAP treatment, co-cultured with plasma-treated human epidermal keratinocytes (hEK) and with an experimental murine model of scleroderma. In hAF and hLSF, 2 min CAP treatment with the MicroPlaSterβ® plasma torch did not affect pro-fibrotic gene expression of alpha smooth muscle actin, fibroblast activating protein, and collagen type I, however, it promoted re-expression of matrix metalloproteinase 1. Functionally, CAP treatment reduced cell migration and stress fiber formation in hAF and hLSF. The relevance of CAP treatment was confirmed in an in vivo model of bleomycin-induced dermal fibrosis. In this model, CAP-treated mice showed significantly reduced dermal thickness and collagen deposition as well as a decrease in both alpha smooth muscle actin-positive myofibroblasts and CD68-positive macrophages in the affected skin in comparison to untreated fibrotic tissue. In conclusion, this study provides the first evidence for the successful use of CAP for treating LS and may be the basis for clinical trials including patients with LS.<br
CRIS-Team WoS Importer:2022-03-04
Keywords: anti-fibrosis; bleomycin-induced fibrosis; cold atmospheric plasma; localized scleroderma

The AP-1 transcription factor FOSL1 causes melanocyte reprogramming and transformation - Maurus, K.; Hufnagel, A.; Geiger, F.; Graf, S.; Berking, C.; Heinemann, A.; Paschen, A.; Kneitz, S.; Stigloher, C.; Geissinger, E.; Otto, C.; Boßerhoff, Anja Katrin; et al. (Oncogene, 2017)
The MAPK pathway is activated in the majority of melanomas and is the target of therapeutic approaches. Under normal conditions, it initiates the so-called immediate early response, which encompasses the transient transcription of several genes belonging to the AP-1 transcription factor family. Under pathological conditions, such as continuous MAPK pathway overactivation due to oncogenic alterations occurring in melanoma, these genes are constitutively expressed. The consequences of a permanent expression of these genes are largely unknown. Here, we show that FOSL1 is the main immediate early AP-1 member induced by melanoma oncogenes. We first examined its role in established melanoma cells. We found that FOSL1 is involved in melanoma cell migration as well as cell proliferation and anoikis-independent growth, which is mediated by the gene product of its target gene HMGA1, encoding a multipotent chromatin modifier. As FOSL1 expression is increased in patient melanoma samples compared to nevi, we investigated the effect of enhanced FOSL1 expression on melanocytes. Intriguingly, we found that FOSL1 acts oncogenic and transforms melanocytes, enabling subcutaneous tumor growth in vivo. During the process of transformation, FOSL1 reprogrammed the melanocytes and downregulated MITF in a HMGA1-dependent manner. At the same time, AXL was upregulated, leading to a shift in the MITF/AXL balance. Furthermore, FOSL1 re-enforced pro-tumorigenic transcription factors MYC, E2F3 and AP-1. Together, this led to the enhancement of several growth-promoting processes, such as ribosome biogenesis, cellular detachment and pyrimidine metabolism. Overall, we demonstrate that FOSL1 is a novel reprogramming factor for melanocytes with potent tumor transformation potential.
EVALuna2:4756

The BAF complex interacts with Pax6 in adult neural progenitors to establish a neurogenic cross-regulatory transcriptional network - Ninkovic, Jovica; Steiner-Mezzadri, Andrea; Jawerka, Melanie; Akinci, Umut; Messerdotti, Giacomo; Petricca, Stefania; Fischer, Judith; Von Holst, Alexander; Beckers, Johanes; Lie, Dieter Chichung; Petrik, David; Miller, Erik; et al. (Cell Stem Cell, 2013)
Numerous transcriptional regulators of neurogenesis have been identified in the developing and adult brain, but how neurogenic fate is programmed at the epigenetic level remains poorly defined. Here, we report that the transcription factor Pax6 directly interacts with the Brg1-containing BAF complex in adult neural progenitors. Deletion of either Brg1 or Pax6 in the subependymal zone (SEZ) causes the progeny of adult neural stem cells to convert to the ependymal lineage within the SEZ while migrating neuroblasts convert to different glial lineages en route to or in the olfactory bulb (OB). Genome-wide analyses reveal that the majority of genes downregulated in the Brg1 null SEZ and OB contain Pax6 binding sites and are also downregulated in Pax6 null SEZ and OB. Downstream of the Pax6-BAF complex, we find that Sox11, Nfib, and Pou3f4 form a transcriptional cross-regulatory network that drives neurogenesis and can convert postnatal glia into neurons. Taken together, elements of our work identify a tripartite effector network activated by Pax6-BAF that programs neuronal fate.
EVALuna2:26321

The broad-spectrum antiinfective drug artesunate interferes with the canonical nuclear factor kappa B (NF-κB) pathway by targeting RelA/p65 - Hutterer, Corina; Niemann, Ina; Milbradt, Jens; Fröhlich, Tony; Reiter, Christoph; Kadioglu, Onat; Bahsi, Hanife; Zeitträger, Isabel; Wagner, Sabrina; Einsiedel, Jürgen; Gmeiner, Peter; Vogel, Nicolas; et al. (Antiviral Research, 2015)
Infection with human cytomegalovirus (HCMV) is a serious medical problem, particularly in immunocompromised individuals and neonates. The success of standard antiviral therapy is hampered by low drug compatibility and induction of viral resistance. A novel strategy is based on the exploitation of cell-directed signaling inhibitors. The broad antiinfective drug artesunate (ART) offers additional therapeutic options such as oral bioavailability and low levels of toxic side-effects. Here, novel ART-derived compounds including dimers and trimers were synthesized showing further improvements over the parental drug. Antiviral activity and mechanistic aspects were determined leading to the following statements: (i) ART exerts antiviral activity towards human and animal herpesviruses, (ii) no induction of ART-resistant HCMV mutants occurred in vitro, (iii) chemically modified derivatives of ART showed strongly enhanced anti-HCMV efficacy, (iv) NF-κB reporter constructs, upregulated during HCMV replication, could be partially blocked by ART treatment, (v) ART activity analyzed in stable reporter cell clones indicated an inhibition of stimulated NF-κB but not CREB pathway, (vi) solid-phase immobilized ART was able to bind to NF-κB RelA/p65, and (vii) peptides within NF-κB RelA/p65 represent candidates of ART binding as analyzed by in silico docking and mass spectrometry. These novel findings open new prospects for the future medical use of ART and ART-related drug candidates.
Keywords: Artesunate and chemical derivatives; Binding of artesunate to NF-κB RelA/p65; Broad antiviral activity; Human cytomegalovirus; Increase of antiviral efficacy; Interference with NF-κB signaling pathways

The Ca2+ sensor protein swiprosin-1/EFhd2 is present in neurites and involved in kinesin-mediated transport in neurons - Purohit, Pavitra; Perez-Branguli, Francesc; Prots, Iryna; Borger, Eva; Gunn-Moore, Frank; Welzel, Oliver; Loy, Kristina; Wenzel, Eva Maria; Groemer, Teja W.; Brachs, Sebastian; Holzer, Max; Buslei, Rolf; et al. (PLoS ONE, 2014)
Swiprosin-1/EFhd2 (EFhd2) is a cytoskeletal Ca2+ sensor protein strongly expressed in the brain. It has been shown to interact with mutant tau, which can promote neurodegeneration, but nothing is known about the physiological function of EFhd2 in the nervous system. To elucidate this question, we analyzed EFhd2-/-/lacZ reporter mice and showed that lacZ was strongly expressed in the cortex, the dentate gyrus, the CA1 and CA2 regions of the hippocampus, the thalamus, and the olfactory bulb. Immunohistochemistry and western blotting confirmed this pattern and revealed expression of EFhd2 during neuronal maturation. In cortical neurons, EFhd2 was detected in neurites marked by MAP2 and co-localized with pre- and post-synaptic markers. Approximately one third of EFhd2 associated with a biochemically isolated synaptosome preparation. There, EFhd2 was mostly confined to the cytosolic and plasma membrane fractions. Both synaptic endocytosis and exocytosis in primary hippocampal EFhd2-/- neurons were unaltered but transport of synaptophysin-GFP containing vesicles was enhanced in EFhd2-/- primary hippocampal neurons, and notably, EFhd2 inhibited kinesin mediated microtubule gliding. Therefore, we found that EFhd2 is a neuronal protein that interferes with kinesin-mediated transport.
EVALuna2:7246

The CD83 Molecule – An Important Immune Checkpoint - Grosche, Linda; Knippertz, Ilka; König, Christina; Royzman, Dmytro; Wild, Andreas; Zinser, Elisabeth; Sticht, Heinrich; Muller, Yves; Steinkasserer, Alexander; Lechmann, Matthias (Frontiers in Immunology, 2020)
The CD83 molecule has been identified to be expressed on numerous activated immune cells, including B and T lymphocytes, monocytes, dendritic cells, microglia, and neutrophils. Both isoforms of CD83, the membrane-bound as well as its soluble form are topic of intensive research investigations. Several studies revealed that CD83 is not a typical co-stimulatory molecule, but rather plays a critical role in controlling and resolving immune responses. Moreover, CD83 is an essential factor during the differentiation of T and B lymphocytes, and the development and maintenance of tolerance. The identification of its interaction partners as well as signaling pathways have been an enigma for the last decades. Here, we report the latest data on the expression, structure, and the signaling partners of CD83. In addition, we review the regulatory functions of CD83, including its striking modulatory potential to maintain the balance between tolerance versus inflammation during homeostasis or pathologies. These immunomodulatory properties of CD83 emphasize its exceptional therapeutic potential, which has been documented in specific preclinical disease models.
CRIS-Team Scopus Importer:2020-05-08
Keywords: autoimmunity; CD83; immune tolerance; Treg cells; viral escape mechanism

The CD83 molecule expressed by dendritic cells is a checkpoint to regulate resolution of inflammation as well as homeostasis within periphery and CNS - Wild, Andreas; Krzyzak, Lena; Mattner, Jochen; Winkler, Thomas; Nitschke, Lars; Steinkasserer, Alexander (2018)
EVALuna2:36214

The cell-intrinsic requirement of Sox6 for cortical interneuron development. - Wegner, Michael; et al. (Neuron, 2009)
We describe the role of Sox6 in cortical interneuron development, from a cellular to a behavioral level. We identify Sox6 as a protein expressed continuously within MGE-derived cortical interneurons from postmitotic progenitor stages into adulthood. Both its expression pattern and null phenotype suggests that Sox6 gene function is closely linked to that of Lhx6. In both Lhx6 and Sox6 null animals, the expression of PV and SST and the position of both basket and Martinotti neurons are abnormal. We find that Sox6 functions downstream of Lhx6. Electrophysiological analysis of Sox6 mutant cortical interneurons revealed that basket cells, even when mispositioned, retain characteristic but immature fast-spiking physiological features. Our data suggest that Sox6 is not required for the specification of MGE-derived cortical interneurons. It is, however, necessary for their normal positioning and maturation. As a consequence, the specific removal of Sox6 from this population results in a severe epileptic encephalopathy. © 2009 Elsevier Inc. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2009.med.IB.LPCIPDBI.thecel
Keywords: DEVBIO; MOLNEURO

The chemical class of quinazoline compounds provides a core structure for the design of anticytomegaloviral kinase inhibitors - Hutterer, Corina; Hamilton, S.; Steingruber, Mirjam; Zeitträger, Isabel; Bahsi, Hanife; Thuma, Natalie; Naing, Z.; Oerfi, Z.; Oerfi, L.; Socher, Eileen; Sticht, Heinrich; Rawlinson, W.; et al. (Antiviral Research, 2016)
HCMV is a member of the family Herpesviridae and represents a worldwide distributed pathogen with seropositivity rates in the adult population ranging between 40% and 90%. Notably, HCMV infection is a serious, sometimes life-threatening medical problem for newborns and immunosuppressed individuals, including transplant recipients and patients under antitumoral chemotherapy. Current standard therapy with valganciclovir has the disadvantage of inducing drug-resistant virus mutants and toxicity-related side effects. Our analysis stresses the earlier finding that kinase inhibitors of the quinazoline class exert an antiviral response by targeting the viral protein kinase pUL97 without inducing resistance. Therefore, quinazolines have been used as a core structure to gain insight in the mode of inhibitor-kinase interaction. Here, we demonstrate that (i) the novel quinazolines Vi7392 and Vi7453 are highly active against HCMV laboratory and clinically relevant strains including maribavir- and ganciclovir-resistant variants, (ii) antiviral activity is not cell-type specific and was also detected in a placental explant tissue model using a genetically intact HCMV strain (iii) the viral kinase pUL97 represents a target of the anticytomegaloviral activity of these compounds, (iv) induction of pUL97-conferring drug resistance was not detectable under single-step selection, thus differed from the induction of ganciclovir resistance, and (v) pUL97 drug docking simulations enabled detailed insights into specific drug-target binding properties providing a promising basis for the design of optimized kinase inhibitors. These novel findings may open new prospects for the future medical use of quinazoline drug candidates and the use of drug-target dynamic simulations for rational design of antivirals.
Keywords: Antiviral drug target; Homology model of pUL97; Human cytomegalovirus; pUL97 drug docking simulation; Quinazoline compounds; Viral kinase pUL97

The class III POU domain protein Brn-1 can fully replace the related Oct-6 during Schwann cell development and myelination. - Wegner, Michael; et al. (Molecular and Cellular Biology, 2005)
For differentiation, Schwann cells rely on the class III POU domain transcription factor Oct-6, which is expressed transiently when Schwann cells have established a one-to-one relation with axons but have not yet started to myelinate. Loss of Oct-6 leads to a transient arrest in this promyelinating stage and a delay in myelination. Although the closely related POU domain protein Brn-2 is coexpressed with Oct-6 in Schwann cells, its loss has only mild consequences. Combined loss of both POU domain proteins, in contrast, dramatically increases the myelination delay, raising the question of how related POU domain proteins compare to each other in their activities. Here, we have replaced Oct-6 expression in the mouse with expression of the class III POU domain protein Brn-1. Although this protein is not normally expressed in Schwann cells, Brn-1 was capable of fully replacing Oct-6. Brn-1 efficiently induced Krox-20 expression as a prerequisite for myelination. Onset and extent of myelination were also indistinguishable from that of the wild type in mice that carried only Brn-1 instead of Oct-6 alleles. Similar to Oct-6, Brn-1 down-regulated its own expression at later stages of myelination. Thus, class III POU domain proteins can fully replace each other in Schwann cell development.
UnivIS-Import:2015-03-09:Pub.2005.med.IB.LPCIPDBI.thecla

The clinical significance of small copy number variants in neurodevelopmental disorders - Asadollahi, Reza; Oneda, Beatrice; Joset, Pascal; Azzarello-Burri, Silvia; Bartholdi, Deborah; Steindl, Katharina; Vincent, Marie; Cobilanschi, Joana; Sticht, Heinrich; Baldinger, Rosa; Reissmann, Regina; Sudholt, Irene; et al. (Journal of Medical Genetics, 2014)
Despite abundant evidence for pathogenicity of large copy number variants (CNVs) in neurodevelopmental disorders (NDDs), the individual significance of genome-wide rare CNVs <500 kb has not been well elucidated in a clinical context.By high-resolution chromosomal microarray analysis, we investigated the clinical significance of all rare non-polymorphic exonic CNVs sizing 1-500 kb in a cohort of 714 patients with undiagnosed NDDs.We detected 96 rare CNVs <500 kb affecting coding regions, of which 58 (60.4%) were confirmed. 6 of 14 confirmed de novo, one of two homozygous and four heterozygous inherited CNVs affected the known microdeletion regions 17q21.31, 16p11.2 and 2p21 or OMIM morbid genes (CASK, CREBBP, PAFAH1B1, SATB2; AUTS2, NRXN3, GRM8). Two further de novo CNVs affecting single genes (MED13L, CTNND2) were instrumental in delineating novel recurrent conditions. For the first time, we here report exonic deletions of CTNND2 causing low normal IQ with learning difficulties with or without autism spectrum disorder. Additionally, we discovered a homozygous out-of-frame deletion of ACOT7 associated with features comparable to the published mouse model. In total, 24.1% of the confirmed small CNVs were categorised as pathogenic or likely pathogenic (median size 130 kb), 17.2% as likely benign, 3.4% represented incidental findings and 55.2% remained unclear.These results verify the diagnostic relevance of genome-wide rare CNVs <500 kb, which were found pathogenic in 2% (14/714) of cases (1.1% de novo, 0.3% homozygous, 0.6% inherited) and highlight their inherent potential for discovery of new conditions.
EVALuna2:9237

The closely related transcription factors Sox4 and Sox11 function as survival factors during spinal cord development. - Hartwig, Anna; Wegner, Michael; Sock, Elisabeth; et al. (Journal of neurochemistry, 2010)
Development of the mouse CNS was reported to be normal in the absence of either Sox4 or its close relative Sox11 despite strong and widespread expression of both transcription factors. In this study, we show that combined absence of both Sox proteins in the mouse leads to severe hypoplasia of the developing spinal cord. Proliferation of neuroepithelial precursor cells in the ventricular zone was unaffected. These cells also acquired their correct positional identity. Both glial and neuronal progenitors were generated and neurons appeared in a similar spatiotemporal pattern as in the wild-type. Rates of cell death were however dramatically increased throughout embryogenesis in the double deficient spinal cord arguing that Sox4 and Sox11 are jointly and redundantly required for cell survival. The absence of pronounced proliferation, patterning, specification, and maturation defects furthermore indicates that the decreased cell survival is not a secondary effect of one of these events. We therefore conclude that the two Sox proteins directly function as pro-survival factors during spinal cord development in neural cell types. © 2010 International Society for Neurochemistry.
UnivIS-Import:2015-03-09:Pub.2010.med.IB.LPCIPDBI.theclo
Keywords: apoptosis; cell survival; gliogenesis; neurogenesis; proliferation; spinal cord

The conformational stability of nonfibrillar amyloid-β peptide oligomers critically depends on the C-terminal peptide length - Socher, Eileen; Sticht, Heinrich; Horn, Anselm (Acs Chemical Neuroscience, 2014)
The amyloid-β (Aβ) peptide is one key molecule in the pathogenesis of Alzheimer's disease. We investigated the conformational stability of a nonfibrillar tetrameric Aβ structure by molecular dynamics (MD) simulations revealing that the stability of the Aβ tetramer depends critically on the C-terminal length. In contrast to the Aβ tetramer, which proved to be instable, the simulations demonstrate structural integrity of the Aβ and Aβ tetramers. These differences in stability can be attributed to an extension of the middle strand of a three-stranded antiparallel β sheet through residues 41-43, only present in the longer Aβ species that aggregate faster and are more neurotoxic. Additional MD simulations demonstrate that this higher stability is also present in the monomers forming the tetramer. In conclusion, our findings suggest the existence of a nonfibrillar oligomer topology that is significantly more stable for the longer Aβ species, thus offering a structural explanation for their higher neurotoxicity. © 2014 American Chemical Societ
Keywords: Abeta43; Alzheimer's disease (AD); amyloid-β (Aβ) peptide; molecular dynamics (MD) simulations; oligomer; tetramer

The Cortical Neuroimmune Regulator TANK Affects Emotional Processing and Enhances Alcohol Drinking: A Translational Study - Müller, Christian P.; Chu, Congying; Qin, Liya; Liu, Chunyu; Xu, Bing; Gao, He; Ruggeri, Barbara; Hieber, Saskia; Schneider, Julia; Jia, Tianye; Tay, Nicole; Akira, Shizuo; et al. (Cerebral Cortex, 2019)
Alcohol abuse is a major public health problem worldwide. Understanding the molecular mechanisms that control regular drinking may help to reduce hazards of alcohol consumption. While immunological mechanisms have been related to alcohol drinking, most studies reported changes in immune function that are secondary to alcohol use. In this report, we analyse how the gene "TRAF family member-associated NF-κB activator" (TANK) affects alcohol drinking behavior. Based on our recent discovery in a large GWAS dataset that suggested an association of TANK, SNP rs197273, with alcohol drinking, we report that SNP rs197273 in TANK is associated both with gene expression (P = 1.16 × 10-19) and regional methylation (P = 5.90 × 10-25). A tank knock out mouse model suggests a role of TANK in alcohol drinking, anxiety-related behavior, as well as alcohol exposure induced activation of insular cortex NF-κB. Functional and structural neuroimaging studies among up to 1896 adolescents reveal that TANK is involved in the control of brain activity in areas of aversive interoceptive processing, including the insular cortex, but not in areas related to reinforcement, reward processing or impulsiveness. Our findings suggest that the cortical neuroimmune regulator TANK is associated with enhanced aversive emotional processing that better protects from the establishment of alcohol drinking behavior.
CRIS-Team Scopus Importer:2019-05-02
Keywords: alcohol; anxiety; drinking; insular cortex; NF-κB; TANK

The crystal structure of the varicella-zoster Orf24-Orf27 nuclear egress complex spotlights multiple determinants of herpesvirus subfamily specificity - Schweininger, Johannes; Kriegel, Mark; Häge, Sigrun; Conrad, Marcus; Alkhashrom, Sewar; Lösing, Josephine; Weiler, Sigrid; Tillmanns, Julia; Egerer-Sieber, Claudia; Decker, Andrea; Rovis, Tihana Lenac; Eichler, Jutta; et al. (Journal of Biological Chemistry, 2022)
Varicella-zoster virus (VZV) is a human pathogen from the α-subfamily of herpesviruses. The VZV Orf24-Orf27 complex represents the essential viral core nuclear egress complex (NEC) that orchestrates the egress of the preassembled virus capsids from the nucleus. While previous studies have primarily emphasized that the architecture of core NEC complexes is highly conserved among herpesviruses, the present report focuses on subfamily-specific structural and functional features that help explain the differences in the autologous versus nonautologous interaction patterns observed for NEC formation across herpesviruses. Here, we describe the crystal structure of the Orf24-Orf27 complex at 2.1 Å resolution. Coimmunoprecipitation and confocal imaging data show that Orf24-Orf27 complex formation displays some promiscuity in a herpesvirus subfamily-restricted manner. At the same time, analysis of thermodynamic parameters of NEC formation of three prototypical α-, β-, and γ herpesviruses, i.e., VZV, human cytomegalovirus (HCMV), and Epstein-Barr virus (EBV), revealed highly similar binding affinities for the autologous interaction with specific differences in enthalpy and entropy. Computational alanine scanning, structural comparisons, and mutational data highlight intermolecular interactions shared among α-herpesviruses that are clearly distinct from those seen in β- and γ-herpesviruses, including a salt bridge formed between Orf24-Arg167 and Orf27-Asp126. This interaction is located outside of the hook-into-groove interface and contributes significantly to the free energy of complex formation. Combined, these data explain distinct properties of specificity and permissivity so far observed in herpesviral NEC interactions. These findings will prove valuable in attempting to target multiple herpesvirus core NECs with selective or broadacting drug candidates.
CRIS-Team Scopus Importer:2022-03-04

The C-terminal coiled-coil domain of Corynebacterium diphtheriae DIP0733 is crucial for interaction with epithelial cells and pathogenicity in invertebrate animal model systems - Weerasekera, Dulanthi; Stengel, Franziska; Sticht, Heinrich; De Mattos Guaraldi, Ana Luiza; Burkovski, Andreas; Azevedo Antunes de Oliveira, Camila (BMC Microbiology, 2018)

The cyclin-dependent kinase inhibitor p27 kip1 regulates radial stem cell quiescence and neurogenesis in the adult hippocampus - Andreu, Zoraida; Khan, Muhammad Amir; Gonzalez-Gomez, Pilar; Negueruela, Santiago; Hortigueela, Rafael; Emeterio, Juana San; Ferron, Sacri R.; Martinez, Gloria; Vidal, Anxo; Farinas, Isabel; Lie, Dieter Chichung; Mira, Helena (Stem Cells, 2015)
Members of the cyclin-dependent kinase (CDK)-inhibitory protein (CIP)/kinase-inhibitory protein (KIP) family of cyclin-dependent kinase inhibitors regulate proliferation and cell cycle exit of mammalian cells. In the adult brain, the CIP/KIP protein p27(kip1) has been related to the regulation of intermediate progenitor cells located in neurogenic niches. Here, we uncover a novel function of p27(kip1) in the adult hippocampus as a dual regulator of stem cell quiescence and of cell-cycle exit of immature neurons. In vivo, p27(kip1) is detected in radial stem cells expressing SOX2 and in newborn neurons of the dentate gyrus. In vitro, the Cdkn1b gene encoding p27(kip1) is transcriptionally upregulated by quiescence signals such as BMP4. The nuclear accumulation of p27(kip1) protein in adult hippocampal stem cells encompasses the BMP4-induced quiescent state and its overexpression is able to block proliferation. p27(kip1) is also expressed in immature neurons upon differentiation of adult hippocampal stem cell cultures. Loss of p27(kip1) leads to an increase in proliferation and neurogenesis in the adult dentate gyrus, which results from both a decrease in the percentage of radial stem cells that are quiescent and a delay in cell cycle exit of immature neurons. Analysis of animals carrying a disruption in the cyclin-CDK interaction domain of p27(kip1) indicates that the CDK inhibitory function of the protein is necessary to control the activity of radial stem cells. Thus, we report that p27(kip1) acts as a central player of the molecular program that keeps adult hippocampal stem cells out of the cell cycle.
EVALuna2:26326

The cyclin-dependent kinase ortholog pUL97 of human cytomegalovirus interacts with cyclins - Graf, Laura; Webel, Rike; Wagner, Sabrina; Hamilton, Stuart T.; Rawlinson, William D.; Sticht, Heinrich; Marschall, Manfred (Viruses, 2013)
The human cytomegalovirus (HCMV)-encoded protein kinase, pUL97, is considered a cyclin-dependent kinase (CDK) ortholog, due to shared structural and functional characteristics. The primary mechanism of CDK activation is binding to corresponding cyclins, including cyclin T1, which is the usual regulatory cofactor of CDK9. This study provides evidence of direct interaction between pUL97 and cyclin T1 using yeast two-hybrid and co-immunoprecipitation analyses. Confocal immunofluorescence revealed partial colocalization of pUL97 with cyclin T1 in subnuclear compartments, most pronounced in viral replication centres. The distribution patterns of pUL97 and cyclin T1 were independent of HCMV strain and host cell type. The sequence domain of pUL97 responsible for the interaction with cyclin T1 was between amino acids 231-280. Additional co-immunoprecipitation analyses showed cyclin B1 and cyclin A as further pUL97 interaction partners. Investigation of the pUL97-cyclin T1 interaction in an ATP consumption assay strongly suggested phosphorylation of pUL97 by the CDK9/cyclin T1 complex in a substrate concentration-dependent manner. This is the first demonstration of interaction between a herpesviral CDK ortholog and cellular cyclins.
EVALuna2:8102

The cytomegalovirus egress proteins pUL50 and pUL53 are translocated to the nuclear envelope through two distinct modes of nuclear import - Schmeiser, Cathrin; Borst, Eva; Sticht, Heinrich; Marschall, Manfred; Milbradt, Jens (Journal of General Virology, 2013)
The nucleocytoplasmic export of cytomegaloviral capsids is regulated by formation of a multi-component nuclear egress complex (NEC), essentially based on viral proteins pUL50 and pUL53. In this study, the generation of recombinant human cytomegaloviruses, expressing tagged versions of pUL50 and pUL53, enabled the investigation of NEC formation in infected primary fibroblasts. For these recombinant viruses, a wild-type-like mode of pUL50-pUL53 interaction and recruitment of both proteins to the nuclear envelope could be demonstrated. Importantly, pUL50 was translocated from an initial cytoplasmic distribution to the nuclear rim, whereas pUL53 accumulated in the nucleus before attaining overall rim colocalization with pUL50. Specified experimental settings illustrated that pUL50 and pUL53 were subject to different pathways of intracellular trafficking. Importantly, a novel nuclear localization signal (NLS) could be identified and functionally verified for pUL53 (amino acids 18-27), whereas no NLS was present in pUL50. Analysis of amino acid replacement mutants further illustrated the differential modes of nuclear import of the two essential viral egress proteins. Taken together, our findings suggest a combination of classical nuclear import (pUL53) and interaction-mediated recruitment (pUL50) as the driving forces for core NEC formation and viral nuclear egress.
EVALuna2:8188

The degenerin region of the human bile acid-sensitive ion channel (BASIC) is involved in channel inhibition by calcium and activation by bile acids. - Ilyaskin, Alexandr; Kirsch, Sonja; Böckmann, Rainer; Sticht, Heinrich; Korbmacher, Christoph; Härteis, Silke; Diakov, Alexei (Pflügers Archiv: European Journal of Physiology, 2018)

The delta subunit of rod-specific photoreceptor cgmp phosphodiesterase (Pde6d) contributes to hepatocellular carcinoma progression - Dietrich, Peter; Hellerbrand, Claus; Boßerhoff, Anja Katrin (Cancers, 2019)
Emerging evidence reveals crucial roles of wild type RAS in liver cancer. The delta subunit of rod-specific photoreceptor cGMP phosphodiesterase (PDE6D) regulates the trafficking of RAS proteins to the plasma membrane and thereby contributes to RAS activation. However, the expression and specific function of PDE6D in hepatocellular carcinoma (HCC) were completely unknown. In this study, PDE6D was newly found to be markedly upregulated in HCC tissues and cell lines. Overexpression of PDE6D in HCC correlated with enhanced tumor stages, tumor grading, and ERK activation. PDE6D depletion significantly reduced proliferation, clonogenicity, and migration of HCC cells. Moreover, PDE6D was induced by TGF-_1, the mediator of stemness, epithelial-mesenchymal transition (EMT), and chemoresistance. In non-resistant cells, overexpression of PDE6D conferred resistance to sorafenib-induced toxicity. Further, PDE6D was overexpressed in sorafenib resistance, and inhibition of PDE6D reduced proliferation and migration in sorafenib-resistant HCC cells. Together, PDE6D was found to be overexpressed in liver cancer and correlated with tumor stages, grading, and ERK activation. Moreover, PDE6D contributed to migration, proliferation, and sorafenib resistance in HCC cells, therefore representing a potential novel therapeutic target.
CRIS-Team Scopus Importer:2019-05-02
Keywords: HCC; KRAS; PDE6D; Sorafenib; TGF-β

The desmin mutation R349P increases contractility and fragility of stem cell-generated muscle micro-tissues - Spörrer, Marina; Kah, Delf-Thorge Eric; Gerum, Richard; Reischl, Barbara; Huraskin, Danyil; Dessalles, Claire A.; Schneider, Werner; Goldmann, Wolfgang; Herrmann, Harald; Thievessen, Ingo; Clemen, Christoph S.; Friedrich, Oliver; et al. (Neuropathology and Applied Neurobiology, 2021)
Aims: Desminopathies comprise hereditary myopathies and cardiomyopathies caused by mutations in the intermediate filament protein desmin that lead to severe and often lethal degeneration of striated muscle tissue. Animal and single cell studies hinted that this degeneration process is associated with massive ultrastructural defects correlating with increased susceptibility of the muscle to acute mechanical stress. The underlying mechanism of mechanical susceptibility, and how muscle degeneration develops over time, however, has remained elusive. Methods: Here, we investigated the effect of a desmin mutation on the formation, differentiation, and contractile function of in vitro-engineered three-dimensional micro-tissues grown from muscle stem cells (satellite cells) isolated from heterozygous R349P desmin knock-in mice. Results: Micro-tissues grown from desmin-mutated cells exhibited spontaneous unsynchronised contractions, higher contractile forces in response to electrical stimulation, and faster force recovery compared with tissues grown from wild-type cells. Within 1 week of culture, the majority of R349P desmin-mutated tissues disintegrated, whereas wild-type tissues remained intact over at least three weeks. Moreover, under tetanic stimulation lasting less than 5 s, desmin-mutated tissues partially or completely ruptured, whereas wild-type tissues did not display signs of damage. Conclusions: Our results demonstrate that the progressive degeneration of desmin-mutated micro-tissues is closely linked to extracellular matrix fibre breakage associated with increased contractile forces and unevenly distributed tensile stress. This suggests that the age-related degeneration of skeletal and cardiac muscle in patients suffering from desminopathies may be similarly exacerbated by mechanical damage from high-intensity muscle contractions. We conclude that micro-tissues may provide a valuable tool for studying the organization of myocytes and the pathogenic mechanisms of myopathies.
CRIS-Team Scopus Importer:2021-12-17
Keywords: desmin; desminopathy; micro-tissue; skeletal muscle physiology; tissue engineering

The Dual-specificity phosphatase Dusp15 is regulated by Sox10 and Myrf in Myelinating Oligodendrocytes - Muth, Katharina; Piefke, Sandra; Weider, Matthias; Sock, Elisabeth; Hermans-Borgmeyer, Irm; Wegner, Michael; Küspert, Melanie (Glia, 2016)
Differentiation of oligodendrocytes and myelin production in the vertebrate central nervous system require highly concerted changes in gene expression. The transcription factors Sox10 and Myrf are both central to this process and jointly regulate expression of myelin genes. Here we show that Sox10 and Myrf also cooperate in the activation of the gene coding for the dual specificity protein phosphatase Dusp15 (also known as VHY) during this process. Activation is mediated by the Dusp15 promoter, which is also sufficient to drive oligodendroglial gene expression in vivo. It contains both a functional Sox10 and a functional Myrf binding site. Whereas Sox10 binds as a monomer, Myrf binds as a trimer. Available data furthermore indicate that cooperative activation is not a function of facilitated binding, but occurs at a later step of the activation process. shRNA-mediated knockdown of Dusp15 reduced expression of early and late differentiation markers in CG4 and primary oligodendroglial cells, whereas Dusp15 overexpression increased it transiently. This argues that Dusp15 is not only a joint target of Sox10 and Myrf in oligodendrocytes but may also mediate some of their effects during oligodendrocyte differentiation and myelin formation. GLIA 2016;64:2120-2132.
EVALuna2:4997

The early retinal progenitor-expressed gene Sox11 regulates the timing of the differentiation of retinal cells. - Sock, Elisabeth; Wegner, Michael; et al. (Development, 2013)
Sry-related HMG box (Sox) proteins, Sox11 and Sox4 are members of the SoxC subtype. We found that Sox11 was strongly expressed in early retinal progenitor cells and that Sox4 expression began around birth, when expression of Sox11 subsided. To analyze the roles of Sox11 and Sox4 in retinal development, we perturbed their expression patterns in retinal explant cultures. Overexpression of Sox11 and Sox4 in retinal progenitors resulted in similar phenotypes: an increased number of cone cells and dramatically decreased numbers of rod cells and Müller glia. Birth-date analysis showed that cone cells were produced at a later developmental stage than that in which cone genesis normally occurs. Sox11-knockout retinas showed delayed onset and progress of differentiation of subsets of retinal cells during the embryonic period. After birth, retinal differentiation took place relatively normally, probably because of the redundant activity of Sox4, which starts to be expressed around birth. Overexpression and loss-of-function analysis failed to provide any evidence that Sox11 and Sox4 directly regulate the transcription of genes crucial to the differentiation of subsets of retinal cells. However, histone H3 acetylation of some early proneural genes was reduced in knockout retina. Thus, Sox11 may create an epigenetic state that helps to establish the competency to differentiate. Taking our findings together, we propose that the sequential expression of Sox11 and Sox4 during retinogenesis leads to the fine adjustment of retinal differentiation by helping to establish the competency of retinal progenitors. © 2013.
UnivIS-Import:2015-03-09:Pub.2013.med.IB.LPCIPDBI.theear
Keywords: Mouse; Progenitor cells; Retina; Sox family transcription factor

The effect of fulvic acid on pre- and postaggregation state of A?17-42: molecular dynamics simulation studies, S. Verma, A. Singh and A. Mishra, Biochim Biophys Acta 1834 (2013) 24-33 - Horn, Anselm; Kahler, Anna (Biochimica Et Biophysica Acta-Proteins and Proteomics, 2013)
EVALuna2:26286

The effects of an overnight holding of whole blood at room temperature on haemoglobin modification and in vitro markers of red blood cell aging - Eckstein, Markus; Zimmermann, Rüdiger; Roth, T.; Hauck-Dlimi, B.; Strasser, E. F.; Xiang, Wei (Vox Sanguinis, 2015)
Some effects of the red blood cell (RBC) storage lesion are well documented whereas others are not. Whether a period of room temperature hold (RTH) during RBC production enhances the RBC storage lesion has remained controversial. In this study, we compared whole blood (WB)-derived RBCs produced after 24-h RTH with rapidly cooled (RC) RBCs and tested them for classical metabolic markers and signs of oxidative damage.SAGM-RBCs were prepared from mixed and split pairs (n = 12) of WB units. RBCs prepared after a 24-h period of RTH on day+1 after collection (RTH-RBCs) were compared with RC-RBCs. All RBCs were stored at 4°C for 42 days with assay of in vitro variables on days+1, +15, +22, +29 and +42. The study examined standard quality parameters, glutathione, catalase and superoxide dismutase (SOD) activities, and indicative markers of oxidative cell damage including post-translational haemoglobin modification, malondialdehyde (MDA), and phosphatidylserine expression.RTH-RBCs exhibited decreased levels of potassium (1·98 ± 0·26 vs. 5·23 ± 0·65 mmol/l) and of 2,3-diphosphoglycerate (2,3-DPG) on day+1 compared with RC-RBCs. Haemolysis rate on day+42 was higher in RTH-RBCs than in RC-RBCs (0·52 ± 0·13 vs. 0·37 ± 0·12%). The phosphatidylserine expression amounted to 0·25 ± 0·20% in RTH-RBCs and 0·07 ± 0·12% in RC-RBCs. Haemoglobin modification was not different between both RBC groups. RTH-RBCs showed slightly higher MDA concentration on days +29 and +42.RC-RBCs and RTH-RBCs show only small differences of classical in vitro parameters and no relevant differences in antioxidative metabolism and oxidative haemoglobin modification. These findings do not explain the loss observed in in vivo survival studies with RBCs.
EVALuna2:4710

The functional consequences of SCN2A mutations determine the phenotype - Begemann, A.; Acuna, M.; Zweier, M.; Sticht, Heinrich; Steindl, K.; Besnard, M.; Hackenberg, A.; Abela, L.; Plecko, B.; Yamakawa, K.; Inoue, Y.; Baumer, A.; et al. (EUROPEAN JOURNAL OF HUMAN GENETICS, 2019)
CRIS-Team WoS Importer:2019-10-25

The GCM domain is a Zn-coordinating DNA-binding domain - Wegner, Michael; et al. (Febs Letters, 2002)
Glial cells missing (GCM) proteins form a small family of transcriptional regulators involved in different developmental processes. They contain a DNA-binding domain that is highly conserved from flies to mice and humans and consists of approximately 150 residues. The GCM domain of the mouse GCM homolog a was expressed in bacteria. Extended X-ray absorption fine structure and particle-induced X-ray emission analysis techniques showed the presence of two Zn atoms with four-fold coordination and cysteine/histidine residues as ligands. Zn atoms can be removed from the GCM domain by the Zn chelator phenanthroline only under denaturating conditions. This suggests that the Zn ions are buried in the interior of the GCM domain and that their removal abolishes DNA-binding because it impairs the structure of the GCM domain. Our results define the GCM domain as a new type of Zn-coordinating, sequence-specific DNA-binding domain. © 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2002.med.IB.LPCIPDBI.thegcm
Keywords: DNA-binding domain; EXAFS; Transcription factor; Zn coordination

The genetic basis for most patients with pustular skin disease remains elusive - Mössner, R.; Wilsmann-Theis, D.; Oji, V.; Gkogkolou, P.; Löhr, S.; Schulz, P.; Körber, A.; Prinz, J. C.; Renner, R.; Schäkel, K.; Vogelsang, L.; Peters, K. P.; et al. (British Journal of Dermatology, 2017)
Rare variants in the genes IL36RN, CARD14 and AP1S3 have been identified to cause/ contribute to pustular skin diseases, primarily generalized pustular psoriasis (GPP).To better understand the disease-relevance of these genes, we screened our cohorts of patients with pustular skin diseases (primarily GPP and palmoplantar pustular psoriasis [PPP]) for coding changes in these three genes. Carriers of single heterozygous IL36RN mutations were screened for a second mutation in IL36RN.Coding exons of IL36RN, CARD14 and AP1S3 were sequenced in 67 patients - 61 with GPP, 2 with acute generalized exanthematous pustulosis and 4 with acrodermatitis continua suppurativa Hallopeau. We screened IL36RN and AP1S3 for intragenic copy-number-variants, 258 PPP patients for coding changes in AP1S3. 11 heterozygous IL36RN mutations carriers were analyzed for a 2(nd) non-coding IL36RN mutation. Genotype-phenotype-correlations in carriers/ non-carriers of IL36RN mutations were assessed within the GPP cohort.The majority of patients (GPP:64%) did not carry rare variants in any of the three genes. Bi-allelic and mono-allelic IL36RN mutations were identified in 15 and 5 GPP patients, respectively. Non-coding rare IL36RN variants were not identified in heterozygous carriers. The only significant genotype-phenotype-correlation observed for IL36RN mutation carriers was early age of disease onset. Additional rare CARD14 or AP1S3 variants were identified in 15% of IL36RN mutations carriers.The identification of IL36RN mutation carriers harboring additional rare variants in CARD14 or AP1S3, indicates a more complex mode of inheritance of pustular psoriasis. Our results suggest additional disease-causing genetic factors in heterozygous IL36RN mutation carriers outside IL36RN. This article is protected by copyright. All rights reserved.
EVALuna2:9330

The genetic landscape and clinical implication of pediatric Moyamoya angiopathy in an international cohort - Zanoni, Paolo; Steindl, Katharina; Sticht, Heinrich; Oneda, Beatrice; Joset, Pascal; Ivanovski, Ivan; Horn, Anselm H.C.; Cabello, Elena M.; Laube, Julia; Zweier, Markus; Baumer, Alessandra; Rauch, Anita; et al. (European Journal of Human Genetics, 2023)
Pediatric Moyamoya Angiopathy (MMA) is a progressive intracranial occlusive arteriopathy that represents a leading cause of transient ischemic attacks and strokes in childhood. Despite this, up to now no large, exclusively pediatric MMA cohort has been subjected to systematic genetic investigation. In this study, we performed molecular karyotyping, exome sequencing and automated structural assessment of missense variants on a series of 88 pediatric MMA patients and correlated genetic, angiographic and clinical (stroke burden) findings. The two largest subgroups in our cohort consisted of RNF213 and neurofibromatosis type 1 (NF1) patients. While deleterious RNF213 variants were associated with a severe MMA clinical course with early symptom onset, frequent posterior cerebral artery involvement and higher stroke rates in multiple territories, NF1 patients had a similar infarct burden compared to non-NF1 individuals and were often diagnosed incidentally during routine MRIs. Additionally, we found that MMA-associated RNF213 variants have lower predicted functional impact compared to those associated with aortic disease. We also raise the question of MMA as a feature of recurrent as well as rare chromosomal imbalances and further support the possible association of MMA with STAT3 deficiency. In conclusion, we provide a comprehensive characterization at the genetic and clinical level of a large exclusively pediatric MMA population. Due to the clinical differences found across genetic subgroups, we propose genetic testing for risk stratification as part of the routine assessment of pediatric MMA patients.
CRIS-Team Scopus Importer:2023-04-14

The glial transcription factor Sox10 binds to DNA both as monomer and dimer with different functional consequences - Wegner, Michael; et al. (Nucleic Acids Research, 2000)
Sox10 is an important transcriptional regulator in the neural crest and various neural-crest derived lineages, such as the Schwann cells of the peripheral nervous system. Recently, we identified the gene for myelin Protein zero (P0) as a transcriptional target of Sox10 in Schwann cells, allowing for the first time a detailed analysis of Sox10 responsive elements and their functional interaction with Sox10. Here we show that Sox10 functions through two different types of DNA response elements, one that allows binding of monomers, and a second that favors cooperative binding of two molecules. This dimeric binding required the presence of two heptameric Sox binding sites in a specific orientation and spacing, and was mediated by an N-terminal region of Sox10 with high conservation in the related Sox9, which also exhibited dimeric binding. This argues that the conserved region has the capacity to function as a DNA-dependent dimerization domain. The interaction between Sox10 dimers and DNA differed dramatically from that of Sox10 monomers, as it drastically reduced the protein's off-rate and increased the protein-induced angle of DNA bending. These results indicate that functionally relevant interactions between Sox10 and DNA occur through completely different modes of binding.
UnivIS-Import:2015-03-05:Pub.2000.med.IB.LPCIPDBI.thegli

The GlyT1 Inhibitor Bitopertin Ameliorates Allodynia and Hyperalgesia in Animal Models of Neuropathic and Inflammatory Pain - Armbruster, Anja; Neumann, Elena; Koetter, Valentin; Hermanns, Henning; Werdehausen, Robert; Eulenburg, Volker (Frontiers in Molecular Neuroscience, 2017)
Background: Chronic pain conditions are difficult to treat and the therapeutic outcome is frequently unsatisfactory. Changes in excitation/inhibition balance within the dorsal horn contribute to the establishment and persistence of chronic pain. Thus, facilitation of inhibitory neurotransmission is a promising approach to treat chronic pain pharmacologically. Glycine transporter 1 (GlyT1) plays an important role in regulating extracellular glycine concentrations. Aim of the present study therefore was to investigate whether the specific GlyT1 inhibitor bitopertin (RG1678; RO4917838) might constitute a novel treatment for chronic pain by facilitating glycinergic inhibition. Methods: Mechanical allodynia and thermal hyperalgesia were induced by chronic constriction injury of the sciatic nerve or carrageenan injections into the plantar surface of the hind paw in rodents. The effect of acute and long-term bitopertin application on the reaction threshold to mechanical and thermal stimuli was determined. General activity was determined in open field experiments. The glycine concentration in cerebrospinal fluid and blood was measured by HPLC. Results: Systemic application of bitopertin in chronic pain conditions lead to a significant increase of the reaction thresholds to mechanical and thermal stimuli in a time and dose-dependent manner. Long-term application of bitopertin effectuated stable beneficial effects over 4 weeks. Bitopertin did not alter reaction thresholds to stimuli in control animals and had no effect on general locomotor activity and anxiety but lead to an increased glycine concentration in cerebrospinal fluid. Conclusion: These findings suggest that inhibition of the GlyT1 by bitopertin represents a promising new approach for the treatment of chronic pain.
EVALuna2:35801

The gut-brain axis in inflammatory bowel disease—current and future perspectives - Günther, Claudia; Rothhammer, Veit; Karow, Marisa; Neurath, Markus; Winner, Beate (International Journal of Molecular Sciences, 2021)
The gut–brain axis is a bidirectional communication system driven by neural, hormonal, metabolic, immunological, and microbial signals. Signaling events from the gut can modulate brain function and recent evidence suggests that the gut–brain axis may play a pivotal role in linking gastrointestinal and neurological diseases. Accordingly, accumulating evidence has suggested a link between inflammatory bowel diseases (IBDs) and neurodegenerative, as well as neuroinflammatory diseases. In this context, clinical, epidemiological and experimental data have demonstrated that IBD predisposes a person to pathologies of the central nervous system (CNS). Likewise, a number of neurological disorders are associated with changes in the intestinal environment, which are indicative for disease-mediated gut–brain inter-organ communication. Although this axis was identified more than 20 years ago, the sequence of events and underlying molecular mechanisms are poorly defined. The emergence of precision medicine has uncovered the need to take into account non-intestinal symptoms in the context of IBD that could offer the opportunity to tailor therapies to individual patients. The aim of this review is to highlight recent findings supporting the clinical and biological link between the gut and brain, as well as its clinical significance for IBD as well as neurodegeneration and neuroinflammation. Finally, we focus on novel human-specific preclinical models that will help uncover disease mechanisms to better understand and modulate the function of this complex system.
CRIS-Team Scopus Importer:2021-08-27
Keywords: Ex vivo organ models; Gut-brain axis; IBD; MS; PD

The High-mobility-group domain of Sox proteins interacts with the DNA-binding domains of many transcription factors. - Wegner, Michael; et al. (Nucleic Acids Research, 2006)
Sox proteins are widely believed to team up with other transcription factors as partner proteins to perform their many essential functions during development. In this study, yeast two-hybrid screens identified transcription factors as a major group of interacting proteins for Sox8 and Sox10. Interacting transcription factors were very similar for these two group E Sox proteins and included proteins with different types of DNA-binding domains, such as homeodomain proteins, zinc finger proteins, basic helix-loop-helix and leucine zipper proteins. In all cases analyzed, the interaction involved the DNA-binding domain of the transcription factor which directly contacted the C-terminal part of the high-mobility-group (HMG) domain. In particular, the C-terminal tail region behind helix 3 of the HMG domain was shown by mutagenesis to be essential for interaction and transcription factor recruitment. The HMG domain thus not only possesses DNA-binding and DNA-bending but also protein-interacting ability which may be equally important for the architectural function of Sox proteins on their target gene promoters. © 2006 Oxford University Press.
UnivIS-Import:2015-03-09:Pub.2006.med.IB.LPCIPDBI.thehig

The high-mobility group transcription factor Sox10 interacts with the N-myc interacting protein Nmi. - Wegner, Michael; et al. (Journal of Molecular Biology, 2005)
The high-mobility group transcription factor Sox10 exerts many different roles during development of the neural crest and nervous system. To unravel its complex transcriptional functions, we have started to look for interaction partners. Here, we identify an association of Sox10 with the N-myc interactor Nmi, which was mediated by the high-mobility group of Sox10 and the central region of Nmi. In vivo relevance of this interaction is indicated by the fact that both proteins were co-expressed in glial cells, gliomas and in the spinal cord. Additionally, subcellular localization of Nmi in C6 glioma depended on the presence of Sox10 such that nuclear Nmi was more frequent in Sox10-expressing cells. Importantly, Nmi modulated the transcriptional activity of Sox10 in reporter gene assays. Nmi effects varied between different Sox10 target gene promoters, indicating that Nmi function in vivo may be promoter-specific. © 2005 Elsevier Ltd. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2005.med.IB.LPCIPDBI.thehig_4
Keywords: Glia; HMG; Sox; Sry; Transcriptional co-activator

The high-mobility-group transcription factor Sox8 is a negative regulator of osteoblast differentiation. - Sock, Elisabeth; Wegner, Michael; et al. (The Journal of Cell Biology, 2005)
Bone remodeling is an important physiologic process that is required to maintain a constant bone mass. This is achieved through a balanced activity of bone-resorbing osteoclasts and bone-forming osteoblasts. In this study, we identify the high mobility group transcription factor Sox8 as a physiologic regulator of bone formation. Sox8-deficient mice display a low bone mass phenotype that is caused by a precocious osteoblast differentiation. Accordingly, primary osteoblasts derived from these mice show an accelerated mineralization ex vivo and a premature expression of osteoblast differentiation markers. To confirm the function of Sox8 as a negative regulator of osteoblast differentiation we generated transgenic mice that express Sox8 under the control of an osteoblast-specific Col1a1 promoter fragment. These mice display a severely impaired bone formation that can be explained by a strongly reduced expression of runt-related transcription factor 2, a gene encoding a transcription factor required for osteoblast differentiation. Together, these data demonstrate a novel function of Sox8, whose tightly controlled expression is critical for bone formation.
UnivIS-Import:2015-03-09:Pub.2005.med.IB.LPCIPDBI.thehig

The human cytomegalovirus nuclear egress complex unites multiple functions: Recruitment of effectors, nuclear envelope rearrangement, and docking to nuclear capsids - Marschall, Manfred; Muller, Yves; Diewald, Benedikt; Sticht, Heinrich; Milbradt, Jens (Reviews in Medical Virology, 2017)
Keywords: antiviral drugs; capsid-NEC docking; herpesviruses; human cytomegalovirus; nuclear egress complex

The IKZF1–IRF4/IRF5 axis controls polarization of myeloma-associated macrophages - Mougiakakos, Dimitrios; Bach, Christian; Böttcher, Martin; Beier, Fabian; Röhner, Linda; Stoll, Andrej; Rehli, Michael; Gebhard, Claudia; Lischer, Christopher; Eberhardt, Martin; Vera, Julio; Büttner-Herold, Maike; et al. (Cancer Immunology Research, 2021)
The bone marrow niche has a pivotal role in progression, survival, and drug resistance of multiple myeloma cells. Therefore, it is important to develop means for targeting the multiple myeloma bone marrow microenvironment. Myeloma-associated macrophages (MAM) in the bone marrow niche are M2 like. They provide nurturing signals to multiple myeloma cells and promote immune escape. Reprogramming M2-like macrophages toward a tumoricidal M1 phenotype represents an intriguing therapeutic strategy. This is especially interesting in view of the successful use of mAbs against multiple myeloma cells, as these therapies hold the potential to trigger macrophage-mediated phagocytosis and cytotoxicity. In this study, we observed that MAMs derived from patients treated with the immunomodulatory drug (IMiD) lenalidomide skewed phenotypically and functionally toward an M1 phenotype. Lenalidomide is known to exert its beneficial effects by modulating the CRBN-CRL4 E3 ligase to ubiquitinate and degrade the transcription factor IKAROS family zinc finger 1 (IKZF1). In M2-like MAMs, we observed enhanced IKZF1 levels that vanished through treatment with lenalidomide, yielding MAMs with a bioenergetic profile, T-cell stimulatory properties, and loss of tumor-promoting capabilities that resemble M1 cells. We also provide evidence that IMiDs interfere epigenetically, via degradation of IKZF1, with IFN regulatory factors 4 and 5, which in turn alters the balance of M1/M2 polarization. We validated our observations in vivo using the CrbnI391V mouse model that recapitulates the IMiD-triggered IKZF1 degradation. These data show a role for IKZF1 in macrophage polarization and can provide explanations for the clinical benefits observed when combining IMiDs with therapeutic antibodies. See related Spotlight on p. 254
CRIS-Team Scopus Importer:2021-03-19

The impact of autophagy on peripheral synapses in health and disease - Rudolf, Rudiger; Khan, Muzamil Majid; Wild, Franziska; Hashemolhosseini, Said (Frontiers in Bioscience, 2016)
Alterations of autophagy have been linked to several peripheral nervous system diseases, such as amyotrophic lateral sclerosis and Charcot-Marie-Tooth disease. Modulation of autophagy by metabolic or pharmacological interventions has been increasingly recognized as a strategy to fight many of these disorders. Cellular processes that are aberrant in case of impaired autophagy and that might lead to these diseases belong to three different categories: (1) clearing of protein aggregates, (2) regulation of vesicle and cargo turnover, and (3) disposal of damaged mitochondria. This review summarizes the present literature that addresses both, the impact and mechanisms of autophagy on the health of the peripheral nervous system and treatment proposals for human disorders associated with impaired autophagy.
EVALuna2:4992

The importance of melanoma inhibitory activity gene family in the tumor progression of oral cancer - Sasahira, Tomonori; Boßerhoff, Anja Katrin; Kirita, Tadaaki (Pathology International, 2018)
Oral squamous cell carcinoma has a high potential for locoregional invasion and nodal metastasis. Consequently, early detection of such malignancies is of immense importance. The melanoma inhibitory activity (MIA) gene family comprises MIA, MIA2, transport and Golgi organization protein 1 (TANGO), and otoraplin (OTOR). These members of the MIA gene family have a highly conserved Src homology 3 (SH3)-like structure. Although the molecules of this family share 34-45% amino acid homology and 47-59% cDNA sequence homology, those members, excluding OTOR, play different tumor-associated functions. MIA has a pivotal role in the progression and metastasis of melanoma; MIA2 and TANGO have been suggested to possess tumor-suppressive functions; and OTOR is uniquely expressed in cochlea of the inner ear. Therefore, the definite functions of the MIA gene family in cancer cells remain unclear. Since the members of the MIA gene family are secreted proteins, these molecules might be useful tumor markers that can be detected in the body fluids, including serum and saliva. In this review, we described the molecular biological functions of the MIA gene family in oral cancer.
EVALuna2:34285

The importance of TM3-4 loop subdomains for functional reconstitution of glycine receptors by independent domains - Unterer, Bea; Becker, Cord-Michael; Villmann, Carmen (Journal of Biological Chemistry, 2012)
Truncated glycine receptors that have been found in human patients suffering from the neuromotor disorder hyperekplexia or in spontaneous mouse models resulted in non-functional ion channels. Rescue of function experiments with the lacking protein portion expressed as a separate independent domain demonstrated restoration of glycine receptor functionality in vitro. This construct harbored most of the TM3-4 loop, TM4, and the C terminus and was required for concomitant transport of the truncated ?1 and the complementation domain from the endoplasmic reticulum toward the cell surface, thereby enabling complex formation of functional glycine receptors. Here, the complementation domain was stepwise truncated from its N terminus in the TM3-4 loop. Truncation of more than 49 amino acids led again to loss of functionality in the receptor complex expressed from two independent domain constructs. We identified residues 357-418 in the intracellular TM3-4 loop as being required for reconstitution of functional glycine-gated channels. All complementation constructs showed cell surface protein expression and correct orientation according to glycine receptor topology. Moreover, we demonstrated that the truncations did not result in a decreased protein-protein interaction between both glycine receptor domains. Rather, deletions of more than 49 amino acids abolished conformational changes necessary for ion channel opening. When the TM3-4 loop subdomain harboring residues 357-418 was expressed as a third independent construct together with the truncated N-terminal and C-terminal glycine receptor domains, functionality of the glycine receptor was again restored. Thus, residues 357-418 represent an important determinant in the process of conformational rearrangements following ligand binding resulting in channel opening.
EVALuna2:4681

The influence of Ep400 on Schwann cell development in mice - Fröb, Franziska; Sock, Elisabeth; Wegner, Michael (GLIA, 2019)
CRIS-Team WoS Importer:2020-01-10

The influence of pre-analytical conditions on platelet-derived microparticles - Eckstein, Fabian; Xiang, Wei; Weiss, Dominik R; Zimmermann, Robert; Strasser, Erwin F (Clinical Laboratory, 2014)
Microparticles (MP) have recently become a focus of both research and clinical investigations. As pre-analytical conditions frequently remain unpublished, further studies are needed to analyze their impact on MP release.This prospective study investigated the effect of sequential storage under three different sets of conditions (fresh; storage at 4 degrees C for 24 hours, SC1; storage at -70 degrees C for 24 hours, SC2) and agitation on platelet-derived MP (PMP) in 11 healthy blood donors (6 male, 5 female). PMP were quantified using flow cytometry (FCM) for analysis of all events positive for both CD41a-PE and Annexin-V-FITC. Newly developed calibration beads for FCM (size of 0.3 - 0.9 microm) were applied for FCM. For functional testing a phospholipid-dependent clotting assay (XACT) was used.PMP concentration increased 1.7-fold in platelet-poor plasma (PPP) under SC1 and further increased 1.6-fold (p < 0.001) under SC2 (p = 0.005). Overall, samples of SC2 had a 5.5-fold increased count of large PMP (0.5 - 0.9 microm) compared to baseline. Results in samples of SC2 ranged from 40.1 seconds to 80.3 seconds but on average the CT was also shortened compared to the CT for SC1 and fresh samples. Additional agitation before PPP preparation reduced the PMP concentration by around 50% (p = 0.025). 135% more small PMP were detected with recently developed calibration beads. Compared to CT (XACT) flow cytometry using Megamix Plus calibration beads is able to reveal significant differences between the analyzed preanalytical conditions.Fresh blood samples should be used for standardizing PMP analysis. Calibration beads for FCM (size of 0.3 - 0.9 microm) have shown to be a reliable tool for PMP quantification especially for PMP of smaller sizes up to 300 nm. Agitation of blood samples before PMP analysis should be avoided. The application of XACT is limited for the analysis of preanalytical conditions.
EVALuna2:4693

The Influence of the histone acetylase Tip60 on Schwann Cell Development in mice - Froeb-Thiele, F.; Tamm, E. R.; Eichele, G.; Wegner, Michael (GLIA, 2021)
CRIS-Team WoS Importer:2021-07-16

The interaction between cyclin B1 and cytomegalovirus protein kinase pUL97 is determined by an active kinase domain - Steingruber, Mirjam; Socher, Eileen; Hutterer, Corina; Webel, Rike; Bergbrede, Tim; Lenac, Tihana; Sticht, Heinrich; Marschall, Manfred (Viruses, 2015)
Replication of human cytomegalovirus (HCMV) is characterized by a tight virus-host cell interaction. Cyclin-dependent protein kinases (CDKs) are functionally integrated into viral gene expression and protein modification. The HCMV-encoded protein kinase pUL97 acts as a CDK ortholog showing structural and functional similarities. Recently, we reported an interaction between pUL97 kinase with a subset of host cyclins, in particular with cyclin T1. Here, we describe an interaction of pUL97 at an even higher affinity with cyclin B1. As a striking feature, the interaction between pUL97 and cyclin B1 proved to be strictly dependent on pUL97 activity, as interaction could be abrogated by treatment with pUL97 inhibitors or by inserting mutations into the conserved kinase domain or the nonconserved C-terminus of pUL97, both producing loss of activity. Thus, we postulate that the mechanism of pUL97-cyclin B1 interaction is determined by an active pUL97 kinase domain.
Keywords: Active conformation; CDK ortholog; Cyclin B; Human cytomegalovirus; Kinase activity; Mode of kinase-cyclin interaction; Protein kinase pUL97; Protein-protein interaction

The Interactive Complex between Cytomegalovirus Kinase vCDK/pUL97 and Host Factors CDK7-Cyclin H Determines Individual Patterns of Transcription in Infected Cells. - Schütz, Martin; Cordsmeier, Arne; Wangen, Christina; Horn, Anselm; Wyler, Emanuel; Enßer, Armin; Sticht, Heinrich; Marschall, Manfred (International Journal of Molecular Sciences, 2023)
The infection of human cytomegalovirus (HCMV) is strongly determined by the host-cell interaction in a way that the efficiency of HCMV lytic replication is dependent on the regulatory interplay between viral and cellular proteins. In particular, the activities of protein kinases, such as cyclin-dependent kinases (CDKs) and the viral CDK ortholog (vCDK/pUL97), play an important role in both viral reproduction and virus-host interaction. Very recently, we reported on the complexes formed between vCDK/pUL97, human cyclin H, and CDK7. Major hallmarks of this interplay are the interaction between cyclin H and vCDK/pUL97, which is consistently detectable across various conditions and host cell types of infection, the decrease or increase in pUL97 kinase activity resulting from cyclin H knock-down or elevated levels, respectively, and significant trans-stimulation of human CDK7 activity by pUL97 in vitro. Due to the fact that even a ternary complex of vCDK/pUL97-cyclin H-CDK7 can be detected by coimmunoprecipitation and visualized by bioinformatic structural modeling, we postulated a putative impact of the respective kinase activities on the patterns of transcription in HCMV-infected cells. Here, we undertook a first vCDK/pUL97-specific transcriptomic analysis, which combined conditions of fully lytic HCMV replication with those under specific vCDK/pUL97 or CDK7 drug-mediated inhibition or transient cyclin H knockout. The novel results were further strengthened using bioinformatic modeling of the involved multi-protein complexes. Our data underline the importance of these kinase activities for the C-terminal domain (CTD) phosphorylation-driven activation of host RNA polymerase in HCMV-infected cells. The impact of the individual experimental conditions on differentially expressed gene profiles is described in detail and discussed.
EVALuna2:545510

The J domain of papovaviral large tumor antigen is required for synergistic interaction with the POU-domain protein Tst-1/Oct6/SCIP - Sock, Elisabeth; Wegner, Michael; et al. (Molecular and Cellular Biology, 1999)
Large T antigens from polyomaviruses are multifunctional proteins with roles in transcriptional regulation, viral DNA replication, and cellular transformation. They have been shown to enhance the activity of various cellular transcription factors. In the case of the POU protein Tst- 1/Oct6/SCIP, this enhancement involves a direct physical interaction between the POU domain of the transcription factor and the amino-terminal region of larger T antigen. Here we have analyzed the structural requirements for synergistic interaction between the two proteins in greater detail. Tst- 1/Oct6/SCIP and the related POU protein Brn-1 were both capable of direct physical interaction with large T antigen. Nevertheless, only Tst-1/Oct6/SCIP functioned synergistically with large T antigen. This differential behavior was due to differences in the amino-terminal regions of the proteins, as evident from chimeras between Tst-1/Oct6/SCIP and Brn-1. Synergy was specifically observed for constructs containing the amino-terminal region of Tst-1/Oct6/SCIP. Large T antigen, on the other hand, functioned synergistically with Tst-1/Oct6/SCIP only when the integrity of its J- domain-containing amino terminus was maintained. Mutations that disrupted the J domain concomitantly abolished the ability to enhance the function of Tst- 1/Oct6/SCIP. The J domain of T antigen was also responsible for the physical interaction with Tst-1/Oct6/SCIP and could be replaced in this property by other J domains. Intriguingly, a heterologous J domain from a human DnaJ protein partially substituted for the amino terminus of T antigen even with regard to the synergistic enhancement of Tst-1/Oct6/SCIP function. Given the general role of J domains, we propose chaperone activity as the underlying mechanism for synergy between Tst-1/Oct6/SCIP and large T antigens.
UnivIS-Import:2015-03-05:Pub.1999.med.IB.LPCIPDBI.thejdo

The large GTPase AtGBPL3 links nuclear envelope formation and morphogenesis to transcriptional repression - Reimann, Theresa; Müdsam, Christina; Schachtler, Christina; Ince, Semra; Sticht, Heinrich; Herrmann, Christian; Stürzl, Michael; Kost, Benedikt (Nature Plants, 2023)
Guanylate binding proteins (GBPs) are prominent regulators of immunity not known to be required for nuclear envelope formation and morphogenesis. Here we identify the Arabidopsis GBP orthologue AtGBPL3 as a lamina component with essential functions in mitotic nuclear envelope reformation, nuclear morphogenesis and transcriptional repression during interphase. AtGBPL3 is preferentially expressed in mitotically active root tips, accumulates at the nuclear envelope and interacts with centromeric chromatin as well as with lamina components transcriptionally repressing pericentromeric chromatin. Reduced expression of AtGBPL3 or associated lamina components similarly altered nuclear morphology and caused overlapping transcriptional deregulation. Investigating the dynamics of AtGBPL3-GFP and other nuclear markers during mitosis (1) revealed that AtGBPL3 accumulation on the surface of daughter nuclei precedes nuclear envelope reformation and (2) uncovered defects in this process in roots of AtGBPL3 mutants, which cause programmed cell death and impair growth. AtGBPL3 functions established by these observations are unique among dynamin-family large GTPases.
CRIS-Team WoS Importer:2023-05-26

The lidocaine metabolite N-ethylglycine has antinociceptive effects in experimental inflammatory and neuropathic pain - Werdehausen, Robert; Mittnacht, Sebastian; Bee, Lucy A.; Minett, Michael S.; Armbruster, Anja; Bauer, Inge; Wood, John N.; Hermanns, Henning; Eulenburg, Volker (Pain, 2015)
Glycine transporter 1 (GlyT1) plays a crucial role in regulating extracellular glycine concentrations and might thereby constitute a new drug target for the modulation of glycinergic inhibition in pain signaling. Consistent with this view, inhibition of GlyT1 has been found to induce antinociceptive effects in various animal pain models. We have shown previously that the lidocaine metabolite N-ethylglycine (EG) reduces GlyT1-dependent glycine uptake by functioning as an artificial substrate for this transporter. Here, we show that EG is specific for GlyT1 and that in rodent models of inflammatory and neuropathic pain, systemic treatment with EG results in an efficient amelioration of hyperalgesia and allodynia without affecting acute pain. There was no effect on motor coordination or the development of inflammatory edema. No adverse neurological effects were observed after repeated high-dose application of EG. EG concentrations both in blood and spinal fluid correlated with an increase of glycine concentration in spinal fluid. The time courses of the EG and glycine concentrations corresponded well with the antinociceptive effect. Additionally, we found that EG reduced the increase in neuronal firing of wide-dynamic-range neurons caused by inflammatory pain induction. These findings suggest that systemically applied lidocaine exerts antihyperalgesic effects through its metabolite EG in vivo, by enhancing spinal inhibition of pain processing through GlyT1 modulation and subsequent increase of glycine concentrations at glycinergic inhibitory synapses. EG and other substrates of GlyT1, therefore, may be a useful therapeutic agent in chronic pain states involving spinal disinhibition.
EVALuna2:4726

The metabotropic glutamate receptor mGluR7b binds to the catalytic -subunit of protein phosphatase 1. - Enz, Ralf (Journal of Neurochemistry, 2002)
Correct targeting of enzymes represents an important biological mechanism to control post-translational modifications of neurotransmitter receptors. The metabotropic glutamate receptor type 7 (mGluR7) exists in two splice variants (mGluR7a and mGluR7b), defined by different C-termini that are phosphorylated by protein kinase C (PKC). Recently, the search for mGluR7a binding partners yielded several proteins that interacted with its C-terminus. Here, a yeast two-hybrid screen using the mGluR7b C-terminus identified both variants of the catalytic γ-subunit of protein phosphatase 1 (PP1γ1 and PP1γ2) as binding partners. The minimal interacting region of PP1γ1/2 contained the core domain and was homologous to a region of PP1α that is needed for functional expression. Although this core domain is highly conserved within the protein phosphatase family, PP1α1 and PP1β did not interact with mGluR7b. Binding between PP1γ1 and mGluR7b might be regulated by alternative splicing, as the variant-specific distal part of the mGluR7b C-terminus mediated the interaction. Within this domain, amino acids involved in the binding to PP1γ1 were mapped and biochemical assays using recombinant and native proteins verified the proposed interaction. Finally, the expression pattern of PP1γ1, PP1γ2 and mGluR7b was analysed in various CNS regions. In summary, these results suggest a regulation of mGluR7b by PP1γ.
UnivIS-Import:2017-12-18:Pub.2002.med.IB.profes_1.themet
Keywords: Expression pattern; G-protein coupled receptor; PP1γ1; PP1γ2; Protein interaction

The molecular Effects of cold atmospheric Plasma on malignant Melanoma - Zimmermann, Tom; Schneider, Christin; Gebhardt, L.; Arndt, S.; Karrer, S.; Zimmermann, J. L.; Fischer, M. J. M.; Boßerhoff, Anja Katrin (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2020)
CRIS-Team WoS Importer:2020-09-11

The myelination-associated G protein-coupled receptor 37 is regulated by Zfp488, Nkx2.2, and Sox10 during oligodendrocyte differentiation - Schmidt, Antonia Luna; Kremp, Marco; Aratake, Takaaki; Cui, Siying; Lin, Yifeng; Zhong, Xiaowen; Lu, Q. Richard; Zhang, Chengfu; Qiu, Mengsheng; Aberle, Tim; Wegner, Michael (Glia, 2024)
Oligodendrocyte differentiation and myelination in the central nervous system are controlled and coordinated by a complex gene regulatory network that contains several transcription factors, including Zfp488 and Nkx2.2. Despite the proven role in oligodendrocyte differentiation little is known about the exact mode of Zfp488 and Nkx2.2 action, including their target genes. Here, we used overexpression of Zfp488 and Nkx2.2 in differentiating CG4 cells to identify aspects of the oligodendroglial expression profile that depend on these transcription factors. Although both transcription factors are primarily described as repressors, the detected changes argue for an additional function as activators. Among the genes activated by both Zfp488 and Nkx2.2 was the G protein-coupled receptor Gpr37 that is important during myelination. In agreement with a positive effect on Gpr37 expression, downregulation of the G protein-coupled receptor was observed in Zfp488- and in Nkx2.2-deficient oligodendrocytes in the mouse. We also identified several potential regulatory regions of the Gpr37 gene. Although Zfp488 and Nkx2.2 both bind to one of the regulatory regions downstream of the Gpr37 gene in vivo, none of the regulatory regions was activated by either transcription factor alone. Increased activation by Zfp488 or Nkx2.2 was only observed in the presence of Sox10, a transcription factor continuously present in oligodendroglial cells. Our results argue that both Zfp488 and Nkx2.2 also act as transcriptional activators during oligodendrocyte differentiation and cooperate with Sox10 to allow the expression of Gpr37 as a modulator of the myelination process.
CRIS-Team Scopus Importer:2024-04-12
Keywords: glia; myelin; seven transmembrane receptor; Sox; transcription factor

The myelin protein PMP2 is regulated by SOX10 and drives melanoma cell invasion - Graf, Saskia Anna; Heppt, Markus Vincent; Wessely, Anja; Krebs, Stefan; Kammerbauer, Claudia; Hornig, Eva; Strieder, Annamarie; Blum, Helmut; Boßerhoff, Anja Katrin; Berking, Carola (Pigment Cell & Melanoma Research, 2019)
The transcription factor sex determining region Y-box 10 (SOX10) plays a key role in the development of melanocytes and glial cells from neural crest precursors. SOX10 is involved in melanoma initiation, proliferation, invasion, and survival. However, specific mediators which impart its oncogenic properties remain widely unknown. To identify target genes of SOX10, we performed RNA sequencing after ectopic expression of SOX10 in human melanoma cells. Among nine differentially regulated genes, peripheral myelin protein 2 (PMP2) was consistently upregulated in several cell lines. Direct regulation of PMP2 by SOX10 was shown by chromatin immunoprecipitation, electrophoretic mobility shift, and luciferase reporter assays. Moreover, a coregulation of PMP2 by SOX10 and early growth response 2 in melanoma cells was found. Phenotypical investigation demonstrated that PMP2 expression can increase melanoma cell invasion. As PMP2 protein was detected only in a subset of melanoma cell lines, it might contribute to melanoma heterogeneity.
CRIS-Team Scopus Importer:2019-05-07
Keywords: glial cell; heterogeneity; invasion; melanoma; PMP2; Schwann cell; SOX10

The neurotrophin Neuritin1 (cpg15) is involved in melanoma migration, attachment independent growth, and vascular mimicry - Boßerhoff, Anja Katrin; Schneider, Nadja; Ellmann, Lisa; Heinzerling, Lucie; Kuphal, Silke (Oncotarget, 2017)
The neurotrophin Neuritin1 (NRN1; cpg15) belongs to the candidate plasticity gene (CPG) family and is expressed in postmitotic-differentiating neurons of the developmental nervous system and neuronal structures associated with plasticity in the brain of human adult.Our newest findings document that NRN1 deregulation could contribute also to disease development and have impact on malignant melanoma. Our analyses displayed the over-expression of NRN1 in melanoma in vitro and in vivo, shown by immunohistochemistry and qRT-PCR on microdissected melanoma tissue; furthermore, soluble NRN1 was detectable in tissue culture supernatant and serum of melanoma patients.To investigate the role of NRN1 in melanoma we performed knockdown, over-expression and recombinant-NRN1-treatment experiments affiliated by functional assays. Our results show that migration, attachment independent growth and vasculogenesis were affected after manipulation of NRN1 on endogenous and extrinsic level. Interestingly, high NRN1 serum levels correlate with low MIA serum levels (< 10ng/ml). Therefore, we speculate that NRN1 could be a marker for early melanoma stages, in particular.In summary, we detected an overexpression of NRN1 in melanoma patient. In functional cell culture experiments we found a correlation between NRN1 expression and the cancerous behavior of melanoma cells.
EVALuna2:4752

The Nonmetabolized β-Blocker Nadolol Is a Substrate of OCT1, OCT2, MATE1, MATE2-K, and P-Glycoprotein, but Not of OATP1B1 and OATP1B3 - Misaka, Shingen; Knop, Jana; Singer, Katrin; Hoier, Eva; Keiser, Markus; Müller, Fabian; Gläser, Hartmut; König, Jörg; Fromm, Martin (Molecular Pharmaceutics, 2016)
Nadolol is a nonmetabolized ?-adrenoceptor antagonist and is a substrate of OATP1A2, but not of OATP2B1. However, other drug transporters involved in translocation of nadolol have not been characterized in detail. We therefore investigated nadolol as a potential substrate of the hepatic uptake transporters OATP1B1, OATP1B3, and OCT1 and of the renal transporters OCT2, MATE1, and MATE2-K expressed in HEK cells. Moreover, the importance of P-glycoprotein (P-gp) for nadolol transport was studied using double transfected MDCK-OCT1-P-gp cells. Nadolol was not transported by OATP1B1 and OATP1B3. In contrast, a significantly higher nadolol accumulation (at 1 and 10 ?M) was found in OCT1, OCT2, MATE1, and MATE2-K cells compared to control cells (P < 0.01). Km values for OCT2-, MATE1-, and MATE2-K-mediated nadolol uptake were 122, 531, and 372 ?M, respectively. Cimetidine (100 ?M, P < 0.01) and trimethoprim (100 ?M, P < 0.001) significantly inhibited OCT1-, OCT2-, MATE1-, and MATE2-K-mediated nadolol transport. The P-gp inhibitor zosuquidar significantly reduced basal to apical nadolol transport in monolayers of MDCK-OCT1-P-gp cells. In summary, nadolol is a substrate of the cation transporters OCT1, OCT2, MATE1, MATE2-K, and of P-gp. These data will aid future in vivo studies on potential transporter-mediated drug-drug or drug-food interactions with involvement of nadolol.
EVALuna2:8690

The Nuclear Envelope Proteins LMNB1 and LBR influence the Chromatin Structure and Senescence Processes in Melanoma - Lämmerhirt, Lisa; Pommer, Michaela; Zimmermann, Tom; Kluge, Viola; Kuphal, Silke; Boßerhoff, Anja Katrin (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2022)
CRIS-Team WoS Importer:2022-09-23

The Oligomeric Assemblies of Cytomegalovirus Core Nuclear Egress Proteins Are Associated with Host Kinases and Show Sensitivity to Antiviral Kinase Inhibitors - Kicuntod, Jintawee; Häge, Sigrun; Hahn, Friedrich; Sticht, Heinrich; Marschall, Manfred (Viruses, 2022)
The nucleo-cytoplasmic capsid egress of herpesviruses is a unique regulated process that ensures the efficiency of viral replication and release. For human cytomegalovirus (HCMV), the core of the nuclear egress complex (NEC) consists of the pUL50–pUL53 heterodimer that is able to oligomerize and thus to build hexameric lattices. These structures determine capsid binding and multicomponent protein interaction including NEC-associated host factors. The underlying characteristic of the core NEC formation is based on the N-terminal hook structure of pUL53 that binds into an alpha-helical groove of pUL50, and is thus described as a hook-into-groove interaction. This central regulatory element has recently been validated as a target of antiviral strategies, and first NEC-targeted prototypes of inhibitory small molecules were reported by our previous study. Here, we further analyzed the oligomerization properties of the viral NEC through an approach of chemical protein cross-linking. Findings were as follows: (i) a cross-link approach demonstrated the oligomeric state of the HCMV core NEC using material from HCMV-infected or plasmid-transfected cells, (ii) a Western blot-based identification of NEC-associated kinases using the cross-linked multicomponent NECs was successful, and (iii) we demonstrated the NEC-inhibitory and antiviral activity of specific inhibitors directed to these target kinases. Combined, the results strongly underline the functional importance of the oligomerization of the HCMV-specific NEC that is both phosphorylation-dependent and sensitive to antiviral kinase inhibitors.
CRIS-Team Scopus Importer:2022-06-03
Keywords: associated protein kinases; core NEC pUL50-pUL53; cross-linking; cyclin-dependent kinases (CDKs); human cytomegalovirus; kinase inhibitors; NEC as an antiviral target; NEC-inhibitory potential; nuclear egress complex (NEC); oligomerization; viral nucleocytoplasmic egress

The peptidyl-prolyl cis/trans isomerase Pin1 interacts with three early regulatory proteins of human cytomegalovirus - Schütz, Martin; Thomas, Marco; Wangen, Christina; Wagner, Sabrina; Rauschert, Luisa; Errerd, Theresa; Kießling, Melissa; Sticht, Heinrich; Milbradt, Jens; Marschall, Manfred (Virus Research, 2020)
Human cytomegalovirus (HCMV) is a ubiquitous human pathogen of high clinical relevance. Despite intensive research of virus-host interaction, crucial details still remain unknown. In this study, the role of the cellular peptidyl-prolyl cis/trans isomerase Pin1 during HCMV infection was investigated. Pin1 is able to recognize phosphorylated serine/threonine-proline motifs and regulates the structural conformation, stability and function of its substrates. Concerning HCMV replication, our recent studies revealed that Pin1 plays an important role in viral nuclear egress by contributing to the depletion of the nuclear lamina at distinct sites through the cis/trans conversion of lamin proteins. Here, novel data illustrate the HCMV-induced upregulation of Pin1 including various cell types being permissive, semi-permissive or non-permissive for productive HCMV replication. Addressing the question of functional impact, Pin1 knock-out (KO) did not show a measurable effect on viral protein expression, at least when assessed by Western blot analysis. Applying highly sensitive methods of qPCR and plaque titration, a pharmacological inhibition of Pin1 activity, however, led to a significant decrease of viral genome equivalents and production of infectious virus, respectively. When focusing on the identification of viral proteins interacting with Pin1 by various coimmunoprecipitation (CoIP) settings, we obtained positive signals for (i) the core nuclear egress complex protein pUL50, (ii) the viral mRNA export factor pUL69 and (iii) the viral DNA polymerase processivity factor pUL44. Confocal immunofluorescence analysis focusing on partial colocalization between Pin1 and the coexpressed viral proteins pUL50, pUL69 or pUL44, respectively, was consistent with the CoIP experiments. Mapping experiments, using transient expression constructs for a series of truncated protein versions and specific replacement mutants, revealed a complex pattern of Pin1 interaction with these three early regulatory HCMV proteins. Data suggest a combination of different modes of Pin1 interactions, involving both classical phosphorylation-dependent Pin1 binding motifs and additional phosphorylation-independent binding sites. Combined, these results support the concept that Pin1 may play an important role in several stages of HCMV infection, thus determining viral replicative efficiency.
CRIS-Team Scopus Importer:2020-06-02
Keywords: Cytomegalovirus replication; Phosphorylation-independent interaction; Pin1 inhibitor-mediated viral replication block; Pin1 interaction with pUL50; Pin1 upregulation; Prolyl cis/trans isomerase Pin1; pUL44; pUL69

The pH-dependent client release from the collagen-specific chaperone HSP47 is triggered by a tandem histidine pair - Oecal, Sinan; Socher, Eileen; Uthoff, Matthias; Ernst, Corvin; Zaucke, Frank; Sticht, Heinrich; Baumann, Ulrich; Gebauer, Jan M. (Journal of Biological Chemistry, 2016)
Heat shock protein 47 (HSP47) is an endoplasmic reticulum (ER)-resident collagen-specific chaperone and essential for proper formation of the characteristic collagen triple helix. It preferentially binds to the folded conformation of its clients and accompanies them from the ER to the Golgi compartment, where it releases them and is recycled back to the ER. Unlike other chaperones, the binding and release cycles are not governed by nucleotide exchange and hydrolysis, but presumably the dissociation of the HSP47-procollagen complex is triggered by the lower pH in the Golgi (pH 6.3) compared with the ER (pH 7.4). Histidine residues have been suggested as triggers due to their approximate textbook pKa value of 6.1 for their side chains. We present here an extensive theoretical and experimental study of the 14 histidine residues present in canine HSP47, where we have mutated all histidine residues in the collagen binding interface and additionally all of those that were predicted to undergo a significant change in protonation state between pH 7 and 6. These mutants were characterized by biolayer interferometry for their pH-dependent binding to a collagen model. One mutant (H238N) loses binding, which can be explained by a rearrangement of the Arg and Asp residues, which are crucial for specific collagen recognition. Most of the other mutants were remarkably silent, but a double mutant with His and His exchanged for asparagines exhibits a much less pronounced pH dependence of collagen binding. This effect is mainly caused by a lower k at the low pH values.

The polynucleotide kinase 3'-phosphatase gene (PNKP) is involved in Charcot-Marie-Tooth disease (CMT2B2) previously related to MED25 - Leal, Alejandro; Bogantes-Ledezma, Sixto; Ekici, Arif Bülent; Uebe, Steffen; Thiel, Christian; Sticht, Heinrich; Berghoff, Martin; Berghoff, Corinna; Morera, Bernal; Meisterernst, Michael; Reis, André (Neurogenetics, 2018)
Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of hereditary peripheral neuropathies. We previously reported a CMT locus on chromosome 19q13.3 segregating with the disease in a large Costa Rican family with axonal neuropathy and autosomal recessive pattern of inheritance (CMT2B2). We proposed a homozygous missense variant in the Mediator complex 25 (MED25) gene as causative of the disease. Nevertheless, the fact that no other CMT individuals with MED25 variants were reported to date led us to reevaluate the original family. Using exome sequencing, we now identified a homozygous nonsense variant (p.Gln517ter) in the last exon of an adjacent gene, the polynucleotide kinase 3'-phosphatase (PNKP) gene. It encodes a DNA repair protein recently associated with recessive ataxia with oculomotor apraxia type 4 (AOA4) and microcephaly, seizures, and developmental delay (MCSZ). Subsequently, five unrelated Costa Rican CMT2 subjects initially identified as being heterozygous for the same MED25 variant were found to be also compound heterozygote for PNKP. All were heterozygous for the same variant found homozygous in the large family and a second one previously associated with ataxia (p.Thr408del). Detailed clinical reassessment of the initial family and the new individuals revealed in all an adult-onset slowly progressive CMT2 associated with signs of cerebellar dysfunction such as slurred speech and oculomotor involvement, but neither microcephaly, seizures, nor developmental delay. We propose that PKNP variants are the major causative variant for the CMT2 phenotype in these individuals and that the milder clinical manifestation is due to an allelic effect.
EVALuna2:35117

The POU protein Oct-6 is a nucleocytoplasmic shuttling protein. - Sock, Elisabeth; Wegner, Michael; et al. (Nucleic Acids Research, 2005)
Like many POU domain proteins, Oct-6 plays important roles during vertebrate development. In accord with its function as a transcriptional regulator during neurogenesis and myelination, Oct-6 is predominantly found in the nucleus. Nuclear import is mediated by a nuclear localization signal at the N-terminal end of the POU homeodomain. Here we show, that Oct-6 in addition contains a nuclear export signal so that Oct-6 is able to shuttle constantly between nucleus and cytoplasm. This nuclear export signal is also localized in the POU homeodomain as part of helix 2 and the connecting loop to DNA recognition helix 3. It conforms to the consensus of hydrophobic leucine-rich export sequences and mediates export from the nucleus via CRM1/Exp1. Several amino acid substitutions or insertions that inactivate this nuclear export sequence, reduce DNA-binding of Oct-6 to its octamer recognition element slighty, but interfere strongly with Oct-6-dependent transcriptional activation, thus arguing that nuclear export and nucleocytoplasmic shuttling are essential aspects of Oct-6 function. Importantly, the nuclear export signal identified for Oct-6 is conserved in most, if not all other vertebrate POU proteins. Nuclear export might therefore be of general relevance for POU protein function throughout development. © The Author 2005. Published by Oxford University Press. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2005.med.IB.LPCIPDBI.thepou

The Prolyl Isomerase Pin1 Promotes the Herpesvirus-Induced Phosphorylation-Dependent Disassembly of the Nuclear Lamina Required for Nucleocytoplasmic Egress - Milbradt, Jens; Hutterer, Corina; Bahsi, Hanife; Wagner, Sabrina; Sonntag, Ellen; Horn, Anselm; Kaufer, Benedikt B.; Mori, Yasuko; Sticht, Heinrich; Fossen, Torgils; Marschall, Manfred (PLoS Pathogens, 2016)
The nuclear lamina lines the inner nuclear membrane providing a structural framework for the nucleus. Cellular processes, such as nuclear envelope breakdown during mitosis or nuclear export of large ribonucleoprotein complexes, are functionally linked to the disassembly of the nuclear lamina. In general, lamina disassembly is mediated by phosphorylation, but the precise molecular mechanism is still not completely understood. Recently, we suggested a novel mechanism for lamina disassembly during the nuclear egress of herpesviral capsids which involves the cellular isomerase Pin1. In this study, we focused on mechanistic details of herpesviral nuclear replication to demonstrate the general importance of Pin1 for lamina disassembly. In particular, Ser22-specific lamin phosphorylation consistently generates a Pin1-binding motif in cells infected with human and animal alpha-, beta-, and gammaherpesviruses. Using nuclear magnetic resonance spectroscopy, we showed that binding of Pin1 to a synthetic lamin peptide induces its cis/trans isomerization in vitro. A detailed bioinformatic evaluation strongly suggests that this structural conversion induces large-scale secondary structural changes in the lamin N-terminus. Thus, we concluded that a Pin1-induced conformational change of lamins may represent the molecular trigger responsible for lamina disassembly. Consistent with this concept, pharmacological inhibition of Pin1 activity blocked lamina disassembly in herpesvirus-infected fibroblasts and consequently impaired virus replication. In addition, a phospho-mimetic Ser22Glu lamin mutant was still able to form a regular lamina structure and overexpression of a Ser22-phosphorylating kinase did not induce lamina disassembly in Pin1 knockout cells. Intriguingly, this was observed in absence of herpesvirus infection proposing a broader importance of Pin1 for lamina constitution. Thus, our results suggest a functional model of similar events leading to disassembly of the nuclear lamina in response to herpesviral or inherent cellular stimuli. In essence, Pin1 represents a regulatory effector of lamina disassembly that promotes the nuclear pore-independent egress of herpesviral capsids.
EVALuna2:8308

The Putative Bromodomain Protein PfBDP7 of the Human Malaria Parasite Plasmodium Falciparum Cooperates With PfBDP1 in the Silencing of Variant Surface Antigen Expression - Quinn, Jennifer; Jeninga, Myriam; Limm, Katharina; Pareek, Kapil; Meißgeier, Tina; Bachmann, Anna; Duffy, Michael F.; Petter, Michaela (Frontiers in Cell and Developmental Biology, 2022)
Epigenetic regulation is a critical mechanism in controlling virulence, differentiation, and survival of the human malaria parasite Plasmodium (P.) falciparum. Bromodomain proteins contribute to this process by binding to acetylated lysine residues of histones and thereby targeting the gene regulatory machinery to gene promoters. A protein complex containing the P. falciparum bromodomain proteins (PfBDP) 1 and PfBDP2 (BDP1/BDP2 core complex) was previously shown to play an essential role for the correct transcription of invasion related genes. Here, we performed a functional characterization of a third component of this complex, which we dubbed PfBDP7, because structural modelling predicted a typical bromodomain fold. We confirmed that PfBDP7 is a nuclear protein that interacts with PfBDP1 at invasion gene promoters in mature schizont stage parasites and contributes to their transcription. Although partial depletion of PfBDP7 showed no significant effect on parasite viability, conditional knock down of either PfBDP7 or PfBDP1 resulted in the de-repression of variant surface antigens (VSA), which are important pathogenicity factors. This de-repression was evident both on mRNA and protein level. To understand the underlying mechanism, we mapped the genome wide binding sites of PfBDP7 by ChIPseq and showed that in early schizonts, PfBDP7 and PfBDP1 are commonly enriched in heterochromatic regions across the gene body of all VSA families, including genes coding for PfEMP1, RIFIN, STEVOR, and PfMC-2TM. This suggests that PfBDP7 and PfBDP1 contribute to the silencing of VSAs by associating with heterochromatin. In conclusion, we identified PfBDP7 as a chromatin binding protein that is a constitutive part of the P. falciparum BDP1/BDP2 core complex and established PfBDP1 and PfBDP7 as novel players in the silencing of heterochromatin regulated virulence gene families of the malaria parasite P. falciparum.
CRIS-Team Scopus Importer:2022-05-06
Keywords: bromodomain; chromatin; malaria; P. falciparum; variant surface antigens

The Quest for Anti-α-Synuclein Antibody Specificity—Lessons Learnt From Flow Cytometry Analysis - Leupold, Lukas; Sigutova, Veronika; Gerasimova, Elizaveta; Regensburger, Martin; Zundler, Sebastian; Zunke, Friederike; Xiang, Wei; Winner, Beate; Prots, Iryna (Frontiers in Neurology, 2022)
The accumulation of alpha-synuclein (aSyn) is the hallmark of a group of neurodegenerative conditions termed synucleopathies. Physiological functions of aSyn, including those outside of the CNS, remain elusive. However, a reliable and reproducible evaluation of aSyn protein expression in different cell types and especially in low-expressing cells is impeded by the existence of a huge variety of poorly characterized anti-aSyn antibodies and a lack of a routinely used sensitive detection methods. Here, we developed a robust flow cytometry-based workflow for aSyn detection and antibody validation. We test our workflow using three commercially available antibodies (MJFR1, LB509, and 2A7) in a variety of human cell types, including induced pluripotent stem cells, T lymphocytes, and fibroblasts, and provide a cell- and antibody-specific map for aSyn expression. Strikingly, we demonstrate a previously unobserved unspecificity of the LB509 antibody, while the MJFR1 clone revealed specific aSyn binding however with low sensitivity. On the other hand, we identified an aSyn-specific antibody clone 2A7 with an optimal sensitivity for detecting aSyn in a range of cell types, including those with low aSyn expression. We further utilize our workflow to demonstrate the ability of the 2A7 antibody to distinguish between physiological differences in aSyn expression in neuronal and non-neuronal cells from the cortical organoids, and in neural progenitors and midbrain dopaminergic neurons from healthy controls and in patients with Parkinson's disease who have aSyn gene locus duplication. Our results provide a proof of principle for the use of high-throughput flow cytometry-based analysis of aSyn and highlight the necessity of rigorous aSyn antibody validation to facilitate the research of aSyn physiology and patholog
Keywords: alpha-synuclein; antibodies; synuclein antibodies; T cell; antibody specificity; flow cytometry; α-synuclein expression

Therapeutic Application of Micellar Solubilized Xanthohumol in a Western-Type Diet-Induced Mouse Model of Obesity, Diabetes and Non-Alcoholic Fatty Liver Disease - Mahli, Abdo; Seitz, Tatjana; Freese, Kim; Frank, Jan; Weiskirchen, Ralf; Abdel-Tawab, Mona; Behnam, Dariush; Hellerbrand, Claus (Cells, 2019)
Xanthohumol (XN), a prenylated chalcone from hops, has been reported to exhibit a variety of health-beneficial effects. However, poor bioavailability may limit its application in the prevention and therapy of diseases. The objective of this study was to determine whether a micellar solubilization of xanthohumol could enhance the bioavailability and biological efficacy of xanthohumol in a Western-type diet (WTD) induced model of obesity, diabetes and non-alcoholic fatty liver disease (NAFLD). After 3 weeks feeding with WTD, XN was additionally applied per oral gavage as micellar solubilizate (s-XN) or native extract (n-XN) at a daily dose of 2.5 mg/kg body weight for a further 8 weeks. Control mice received vehicle only in addition to the WTD. WTD-induced body weight-gain and glucose intolerance were significantly inhibited by s-XN application. Furthermore, WTD-induced hepatic steatosis, pro-inflammatory gene expression (MCP-1 and CXCL1) and immune cell infiltration as well as activation of hepatic stellate cells (HSC) and expression of collagen alpha I were significantly reduced in the livers of s-XN-treated mice compared to WTD controls. In contrast, application of n-XN had no or only slight effects on the WTD-induced pathological effects. In line with this, plasma XN concentration ranged between 100-330 nmol/L in the s-XN group while XN was not detectable in the serum samples of n-XN-treated mice. In conclusion, micellar solubilization enhanced the bioavailability and beneficial effects of xanthohumol on different components of the metabolic syndrome including all pathological steps of NAFLD. Notably, this was achieved in a dose more than 10-fold lower than effective beneficial doses of native xanthohumol reported in previous in vivo studies.
CRIS-Team WoS Importer:2019-06-18

Therapeutic Inhibition of Inflammatory Monocyte Recruitment Reduces Steatohepatitis and Liver Fibrosis - Krenkel, Oliver; Puengel, Tobias; Govaere, Olivier; Abdallah, Ali T.; Mossanen, Jana C.; Kohlhepp, Marlene; Liepelt, Anke; Lefebvre, Eric; Luedde, Tom; Hellerbrand, Claus; Weiskirchen, Ralf; Longerich, Thomas; et al. (Hepatology, 2017)
Macrophages are key regulators of liver fibrosis progression and regression in nonalcoholic steatohepatitis (NASH). Liver macrophages comprise resident phagocytes, Kupffer cells, and monocyte-derived cells, which are recruited via the chemokine receptor CCR2. We aimed at elucidating the therapeutic effects of inhibiting monocyte infiltration in NASH models by using cenicriviroc (CVC), an oral dual chemokine receptor CCR2/CCR5 antagonist that is under clinical evaluation. Human liver tissue from NASH patients were analyzed for CCR2+ macrophages and administration of CVC was tested in mouse models of steatohepatitis, liver fibrosis progression and fibrosis regression. In human liver from n=17 patients and n=4 controls, CCR2+ macrophages increased parallel to NASH severity and fibrosis stage, with a concomitant inflammatory polarization of these CD68+, portal monocyte-derived macrophages (MoMF). Similar to human disease, we observed a massive increase of hepatic MoMF in experimental models of steatohepatitis and liver fibrosis. Therapeutic treatment with CVC significantly reduced the recruitment of hepatic Ly- 6C+ MoMF in all models. In experimental steatohepatitis with obesity, therapeutic CVC application significantly improved insulin resistance and hepatic triglyceride levels. In fibrotic steatohepatitis, CVC treatment ameliorated histological NASH activity and hepatic fibrosis. CVC inhibited the infiltration of Ly-6C+ monocytes, without direct effects on macrophage polarization, hepatocyte fatty acid metabolism or stellate cell activation. Importantly, CVC did not delay fibrosis resolution after injury cessation. RNA sequencing analysis revealed that MoMF, but not Kupffer cells, specifically upregulate multiple growth factors and cytokines associated with fibrosis progression, while Kupffer cells activated pathways related to inflammation initiation and lipid metabolism. In conclusion, pharmacological inhibition of CCR2+ monocyte recruitment efficiently ameliorates insulin resistance, hepatic inflammation and fibrosis, corroborating the therapeutic potential of CVC in patients with NASH. This article is protected by copyright. All rights reserved.
EVALuna2:4779

The reaction mechanism of bovine lens leucine aminopeptidase - Schürer, Gudrun; Horn, Anselm; Gedeck, Peter; Clark, Timothy (Journal of Physical Chemistry B, 2002)
We present a quantum mechanical/molecular mechanical (QM/MM) study using the AMI Hamiltonian and a flexible MM part on the mode of action of the bovine lens leucine aminopeptidase (blLAP), a cytosolic exopeptidase that catalyzes the cleavage of the N-terminal amide bond of peptides. The reaction mechanism of this ubiquitous enzyme has not yet been clarified completely, although some suggestions based on crystallographic data have been made. One path of the several possibilities investigated was found to be clearly the most favorable and in good agreement with experimental results. Besides the elucidation of the functional roles of active-site residues, an estimation of the environment effects is given.

The recurrent missense mutation p.(Arg367Trp) in YARS1 causes a distinct neurodevelopmental phenotype - Averdunk, Luisa; Sticht, Heinrich; Surowy, Harald; Luedecke, Hermann-Josef; Koch-Hogrebe, Margarete; Alsaif, Hessa S.; Kahrizi, Kimia; Alzaidan, Hamad; Alawam, Bashayer S.; Tohary, Mohamed; Kraus, Cornelia; Endele, Sabine; et al. (Journal of Molecular Medicine, 2021)
Pathogenic variants in aminoacyl-tRNA synthetases (ARS1) cause a diverse spectrum of autosomal recessive disorders. Tyrosyl tRNA synthetase (TyrRS) is encoded by YARS1 (cytosolic, OMIM*603,623) and is responsible of coupling tyrosine to its specific tRNA. Next to the enzymatic domain, TyrRS has two additional functional domains (N-Terminal TyrRS(Mini) and C-terminal EMAP-II-like domain) which confer cytokine-like functions. Mutations in YARS1 have been associated with autosomal-dominant Charcot-Marie-Tooth (CMT) neuropathy type C and a heterogenous group of autosomal recessive, multisystem diseases. We identified 12 individuals from 6 families with the recurrent homozygous missense variant c.1099C > T;p.(Arg367Trp) (NM_003680.3) in YARS1. This variant causes a multisystem disorder with developmental delay, microcephaly, failure to thrive, short stature, muscular hypotonia, ataxia, brain anomalies, microcytic anemia, hepatomegaly, and hypothyroidism. In silico analyses show that the p.(Arg367Trp) does not affect the catalytic domain responsible of enzymatic coupling, but destabilizes the cytokine-like C-terminal domain. The phenotype associated with p.(Arg367Trp) is distinct from the other biallelic pathogenic variants that reside in different functional domains of TyrRS which all show some common, but also divergent clinical signs [(e.g., p.(Phe269Ser)-retinal anomalies, p.(Pro213Leu)/p.(Gly525Arg)-mild ID, p.(Pro167Thr)-high fatality)]. The diverse clinical spectrum of ARS1-associated disorders is related to mutations affecting the various non-canonical domains of ARS1, and impaired protein translation is likely not the exclusive disease-causing mechanism of YARS1- and ARS1-associated neurodevelopmental disorders. Key messages The missense variant p.(Arg367Trp) in YARS1 causes a distinct multisystem disorder. p.(Arg367Trp) affects a non-canonical domain with cytokine-like functions. Phenotypic heterogeneity associates with the different affected YARS1 domains. Impaired protein translation is likely not the exclusive mechanism of ARS1-associated disorders.
CRIS-Team WoS Importer:2021-10-01

The recurrent TCF4 missense variant p.(Arg389Cys) causes a neurodevelopmental disorder overlapping with but not typical for Pitt-Hopkins syndrome - Popp, Bernt; Bienvenu, Thierry; Giurgea, Irina; Metreau, Julia; Kraus, Cornelia; Reis, André; Fischer, Jan; Bralo, Maria Palomares; Tenorio-Castano, Jair; Lapunzina, Pablo; Almoguera, Berta; Lopez-Grondona, Fermina; et al. (Clinical Genetics, 2022)
TCF4 haploinsufficiency by deletions, truncating variants or loss-of-function missense variants within the DNA-binding and protein interacting bHLH domain causes Pitt-Hopkins syndrome (PTHS). This neurodevelopmental disorder (NDD) is characterized by severe intellectual disability (ID), epilepsy, hyperbreathing and a typical facial gestalt. Only few aberrations of the N-terminus of TCF4 were associated with milder or atypical phenotypes. By personal communication and searching databases we assembled six cases with the novel, recurrent, de novo missense variant c.1165C > T, p.(Arg389Cys) in TCF4. This variant was identified by diagnostic exome or panel sequencing and is located upstream of the bHLH domain. All six individuals presented with moderate to severe ID with language impairment. Microcephaly occurred in two individuals, epilepsy only in one, and no breathing anomalies or myopia were reported. Facial gestalt showed some aspects of PTHS but was rather non-specific in most individuals. Interestingly, the variant is located within the AD2 activation domain next to a highly conserved coactivator-recruitment motif and might alter interaction with coactivator proteins independently from the bHLH domain. Our findings of a recurrent missense variant outside the bHLH domain in six individuals with an ID phenotype overlapping with but not typical for PTHS delineate a novel genotype-phenotype correlation for TCF4-related NDDs.
CRIS-Team WoS Importer:2022-09-02

The role of chromatin remodeling complexes in Schwann cell development - Fröb, Franziska; Wegner, Michael (Glia, 2019)
Schwann cells develop from neural crest cells in an ordered series of events and give rise to myelinating and nonmyelinating subtypes. In their mature state, myelinating Schwann cells produce myelin sheaths that provide trophic support to axons and allow saltatory conduction in the vertebrate peripheral nervous system. Each step of Schwann cell development requires defined changes in chromatin structure that are catalyzed by chromatin remodeling complexes. Over the last years, all major types of chromatin remodeling complexes have been detected in Schwann cells and several have been functionally analyzed. SWI/SNF-type, CHD-type, and INO80/SWR-type chromatin remodelers in particular have been shown to interact with multiple cell-type specific transcription factors and histone modifiers and to be important regulators of Schwann cell development. As a result of different recruitment strategies, each chromatin remodeler targets defined genomic areas and impacts unique mechanisms at specific stages of Schwann cell development. Chromatin remodeling complexes undoubtedly constitute essential components of the Schwann cell regulatory network.
CRIS-Team WoS Importer:2019-12-27

The role of dead cell clearance in the etiology and pathogenesis of systemic lupus erythematosus: dendritic cells as potential targets - Biermann, Mona; Veissi, Susan; Maueröder, Christian; Chaurio Gonzalez, Ricardo Alfredo; Berens, Christian; Herrmann, Martin; Munoz Becerra, Luis (Expert Review of Clinical Immunology, 2014)
Overwhelming apoptosis combined with a deficiency in clearing apoptotic cells is thought to be an important etiopathogenic event in the autoimmune disease systemic lupus erythematosus (SLE). Lazy macrophages, complement or DNase I deficiency as well as insufficient natural IgM might be important factors leading to such a clearance deficiency. A defective clearance of apoptotic cells leads to the activation and maturation of plasmacytoid and myeloid dendritic cells (DCs) by material derived from secondary necrotic cells carrying modified autoantigens. This results in the presentation of autoantigens to autoreactive T and B cells in an immunogenic manner, thereby leading to autoantibody production, chronic inflammation and severe tissue damage. Since DC activation and IFN-? production by plasmacytoid dendritic cells play a critical role in the course of SLE pathogenesis, therapeutic intervention to end this vicious cycle might be a promising approach for treating the disease.
EVALuna2:13019

The Role of NRN1 in the Development and Progression of malignant Melanoma - Haller, Lucia; Reichelt, Judith; Boßerhoff, Anja Katrin; Kuphal, Silke (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2021)
CRIS-Team WoS Importer:2021-09-24

The role of protein kinase CK2 in skeletal muscle: Myogenesis, neuromuscular junctions, and rhabdomyosarcoma - Hashemolhosseini, Said (Neuroscience Letters, 2020)
For the first time, a review article focuses exclusively on the role of the protein kinase CK2 in mono- and poly-nucleated mammalian skeletal muscle cells. While CK2, a pleiotropic serine/threonine kinase was originally thought to phosphorylate mainly casein, later evidence found glycogen phosphorylase and glycogen synthase also to be a target, linking the enzyme to muscle biology. Indeed, recent studies have shown that CK2 is involved in many different steps in the biology of striated skeletal muscle, such as myogenesis and homeostasis in the adult muscle, and even at the neuromuscular junctions, the points of contact between the muscle fibers and the motor nerves end. Next to the role of CK2 in muscle physiology, this review also highlights the contribution of CK2 in muscle pathologies, such as muscle tumors and myopathies.
CRIS-Team Scopus Importer:2020-05-15
Keywords: Myogenesis; Neuromuscular junction; Protein kinase CK2; Rhabdomyosarcoma; Skeletal muscle

The role of recessive inheritance in early-onset epileptic encephalopathies: a combined whole-exome sequencing and copy number study - Papuc, Sorina M.; Abela, Lucia; Steindl, Katharina; Begemann, Anais; Simmons, Thomas L.; Schmitt, Bernhard; Zweier, Markus; Oneda, Beatrice; Socher, Eileen; Crowther, Lisa M.; Wohlrab, Gabriele; Gogoll, Laura; et al. (European journal of human genetics, 2019)
Early-onset epileptic encephalopathy (EE) and combined developmental and epileptic encephalopathies (DEE) are clinically and genetically heterogeneous severely devastating conditions. Recent studies emphasized de novo variants as major underlying cause suggesting a generally low-recurrence risk. In order to better understand the full genetic landscape of EE and DEE, we performed high-resolution chromosomal microarray analysis in combination with whole-exome sequencing in 63 deeply phenotyped independent patients. After bioinformatic filtering for rare variants, diagnostic yield was improved for recessive disorders by manual data curation as well as molecular modeling of missense variants and untargeted plasma-metabolomics in selected patients. In total, we yielded a diagnosis in similar to 42% of cases with causative copy number variants in 6 patients (similar to 10%) and causative sequence variants in 16 established disease genes in 20 patients (similar to 32%), including compound heterozygosity for causative sequence and copy number variants in one patient. In total, 38% of diagnosed cases were caused by recessive genes, of which two cases escaped automatic calling due to one allele occurring de novo. Notably, we found the recessive gene SPATA5 causative in as much as 3% of our cohort, indicating that it may have been underdiagnosed in previous studies. We further support candidacy for neurodevelopmental disorders of four previously described genes (PIK3AP1, GTF3C3, UFC1, and WRAP53), three of which also followed a recessive inheritance pattern. Our results therefore confirm the importance of de novo causative gene variants in EE/DEE, but additionally illustrate the major role of mostly compound heterozygous or hemizygous recessive inheritance and consequently high-recurrence risk.
CRIS-Team WoS Importer:2019-02-27

The role of recessive inheritance in early-onset epileptic encephalopathies: a combined whole-exome sequencing and high-resolution copy number study - Papuc, S.; Abela, L.; Steindl, K.; Begemann, A.; Simmons, T.; Schmitt, B.; Zweier, M.; Oneda, B.; Socher, Eileen; Crowther, L.; Wohlrab, G.; Gogoll, L.; et al. (EUROPEAN JOURNAL OF HUMAN GENETICS, 2019)
CRIS-Team WoS Importer:2019-10-25

The role of Tcf4 in oligodendrocyte development - Wedel, Miriam; Wegner, Michael (GLIA, 2019)
CRIS-Team WoS Importer:2020-01-10

The Role of the Transcription Factor AP2e in the Development of malignant Melanoma - Stabler, S.; Rottensteiner-Brandl, Ulrike; Boßerhoff, Anja Katrin (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2021)
CRIS-Team WoS Importer:2021-09-24

The role of zinc finger transcription factor Zfp276 during glial development - Küspert, Melanie; Sock, Elisabeth; Wegner, Michael (2017)
EVALuna2:33482

The Runx1/AML1 transcription factor selectively regulates development and survival of TrkA nociceptive sensory neurons. - Wegner, Michael; et al. (Nature Neuroscience, 2006)
Neural crest cells (NCCs) can adopt different neuronal fates. In NCCs, neurogenin-2 promotes sensory specification but does not specify different subclasses of sensory neurons. Understanding the gene cascades that direct Trk gene activation may reveal mechanisms generating sensory diversity, because different Trks are expressed in different sensory neuron subpopulations. Here we show in chick and mouse that the Runt transcription factor Runx1 promotes axonal growth, is selectively expressed in neural crest-derived TrkA+ sensory neurons and mediates TrkA transactivation in migratory NCCs. Inhibition of Runt activity depletes TrkA expression and leads to neuronal death. Moreover, Runx1 overexpression is incompatible with multipotency in the migratory neural crest but does not induce expression of pan-neuronal genes. Instead, Runx1-induced neuronal differentiation depends on an existing neurogenin2 proneural gene program. Our data show that Runx1 directs, in a context-dependent manner, key aspects of the establishment of the TrkA + nociceptive subclass of neurons. © 2006 Nature Publishing Group.
UnivIS-Import:2015-03-09:Pub.2006.med.IB.LPCIPDBI.therun

The soluble CD83 molecule accelerates wound closure and improves wound healing quality - Royzman, Dmytro; Peckert-Maier, Katrin; Stich, Lena; Wild, Andreas; Ostalecki, Christian; Seyferth, Stefan; Eming, Sabine A.; Fuchs, Maximilian; Kunz, Meik; Sturmer, Ewa K.; Peters, Eva M. J.; Berking, Carola; et al. (WOUND REPAIR AND REGENERATION, 2022)
CRIS-Team WoS Importer:2022-09-16

The soluble CD83 protein prevents bone destruction by inhibiting the formation of osteoclasts and inducing resolution of inflammation in arthritis - Royzman, Dmytro; Andreev, Darja; Stich, Lena; Peckert, Katrin; Wild, Andreas; Zinser, Elisabeth; Mühl-Zürbes, Petra; Jones, Evan; Adam, Susanne; Frey, Silke; Fuchs, Maximilian; Kunz, Meik; et al. (Frontiers in Immunology, 2022)
Here we show that soluble CD83 induces the resolution of inflammation in an antigen-induced arthritis (AIA) model. Joint swelling and the arthritis-related expression levels of IL-1 beta, IL-6, RANKL, MMP9, and OC-Stamp were strongly reduced, while Foxp3 was induced. In addition, we observed a significant inhibition of TRAP(+) osteoclast formation, correlating with the reduced arthritic disease score. In contrast, cell-specific deletion of CD83 in human and murine precursor cells resulted in an enhanced formation of mature osteoclasts. RNA sequencing analyses, comparing sCD83- with mock treated cells, revealed a strong downregulation of osteoclastogenic factors, such as Oc-Stamp, Mmp9 and Nfatc1, Ctsk, and Trap. Concomitantly, transcripts typical for pro-resolving macrophages, e.g., Mrc1/2, Marco, Klf4, and Mertk, were upregulated. Interestingly, members of the metallothionein (MT) family, which have been associated with a reduced arthritic disease severity, were also highly induced by sCD83 in samples derived from RA patients. Finally, we elucidated the sCD83-induced signaling cascade downstream to its binding to the Toll-like receptor 4/(TLR4/MD2) receptor complex using CRISPR/Cas9-induced knockdowns of TLR4/MyD88/TRIF and MTs, revealing that sCD83 acts via the TRIF-signaling cascade. In conclusion, sCD83 represents a promising therapeutic approach to induce the resolution of inflammation and to prevent bone erosion in autoimmune arthritis.
CRIS-Team WoS Importer:2022-09-09

The Sox9 transcription factor determines glial fate choice in the developing spinal cord. - Sock, Elisabeth; Wegner, Michael; Stolt, Claus; et al. (Genes & Development, 2003)
The mechanism that causes neural stem cells in the central nervous system to switch from neurogenesis to gliogenesis is poorly understood. Here we analyzed spinal cord development of mice in which the transcription factor Sox9 was specifically ablated from neural stem cells by the CRE/loxP recombination system. These mice exhibit defects in the specification of oligodendrocytes and astrocytes, the two main types of glial cells in the central nervous system. Accompanying an early dramatic reduction in progenitors of the myelin-forming oligodendrocytes, there was a transient increase in motoneurons. Oligodendrocyte progenitor numbers recovered at later stages of development, probably owing to compensatory actions of the related Sox10 and Sox8, both of which overlap with Sox9 in the oligodendrocyte lineage. In agreement, compound loss of Sox9 and Sox10 led to a further decrease in oligodendrocyte progenitors. Astrocyte numbers were also severely reduced in the absence of Sox9 and did not recover at later stages of spinal cord development. Taking the common origin of motoneurons and oligodendrocytes as well as V2 interneurons and some astrocytes into account, stem cells apparently fail to switch from neurogenesis to gliogenesis in at least two domains of the ventricular zone, indicating that Sox9 is a major molecular component of the neuron-glia switch in the developing spinal cord.
UnivIS-Import:2015-03-09:Pub.2003.med.IB.LPCIPDBI.thesox
Keywords: Astrocyte; HMG-box; Neural stem cell; Oligodendrocyte; Sox10; Sry

The splicing factor PHF5A influences the growth and variability of melanoma cells - Meissgeier, T.; Linck-Paulus, Lisa; Boßerhoff, Anja Katrin (JOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, 2022)
CRIS-Team WoS Importer:2022-09-23

The structure and stability of Si-60 and Ge-60 cages: A computational study - Chen, Zhongfang; Jiao, Haijun; Horn, Anselm; Clark, Timothy; Thiel, Walfried; Schleyer, Paul; et al. (Journal of Computational Chemistry, 2003)
Structural studies of fullerene-like Si-60 and Ge-60 cages using ab initio methods were augmented by density functional tight-binding molecular dynamics (DFTB-MD) simulations of finite temperature effects. Neither the perfect I-h symmetry nor the distorted T-h structures are true minima. The energies of both are high relative to distorted, lower symmetry minima, C-i and T, respectively, which still preserve C-60-type connectivity. Both Si-60 and Ge-60 favor C-i symmetry cages in which Si and Ge vertexes exhibit either near-trigonal or pyramidal geometries. These structural variations imply significant reactivity differences between different positions. The small magnetic shielding effects (NICS) indicate that aromaticity is not important in these systems. The inorganic fullerene cages have lower stabilities compared with their carbon analogs. Si-60 is stable towards spontaneous disintegration up to 700 K according to DFTB-MD simulations, and thus has potential for experimental observation. In contrast, Ge-60 preserves its cage structure only up to 200 K. (C) 2003 Wiley Periodicals, Inc.
Keywords: inorganic fullerenes; Si-60; Ge-60; DFT; DFTB

The TAX1 binding protein 1 is expressed in the retina and interacts with the GABAC receptor rho1 subunit. - Ulrich, Melanie; Seeber, Silke; Becker, Cord-Michael; Enz, Ralf (Biochemical Journal, 2007)
UnivIS-Import:2015-04-14:Pub.2007.med.IB.profes_1.thetax

The temporal expression pattern of alpha-synuclein modulates olfactory neurogenesis in transgenic mice - Schreglmann, Sebastian R.; Regensburger, Martin; Rockenstein, Edward; Masliah, Eliezer; Xiang, Wei; Winkler, Jürgen; Winner, Beate (PLoS ONE, 2015)
Adult neurogenesis mirrors the brain´s endogenous capacity to generate new neurons throughout life. In the subventricular zone/ olfactory bulb system adult neurogenesis is linked to physiological olfactory function and has been shown to be impaired in murine models of neuronal alpha-Synuclein overexpression. We analyzed the degree and temporo-spatial dynamics of adult olfactory bulb neurogenesis in transgenic mice expressing human wild-type alpha-Synuclein (WTS) under the murine Thy1 (mThy1) promoter, a model known to have a particularly high tg expression associated with impaired olfaction.Survival of newly generated neurons (NeuN-positive) in the olfactory bulb was unchanged in mThy1 transgenic animals. Due to decreased dopaminergic differentiation a reduction in new dopaminergic neurons within the olfactory bulb glomerular layer was present. This is in contrast to our previously published data on transgenic animals that express WTS under the control of the human platelet-derived growth factor ? (PDGF) promoter, that display a widespread decrease in survival of newly generated neurons in regions of adult neurogenesis, resulting in a much more pronounced neurogenesis deficit. Temporal and quantitative expression analysis using immunofluorescence co-localization analysis and Western blots revealed that in comparison to PDGF transgenic animals, in mThy1 transgenic animals WTS is expressed from later stages of neuronal maturation only but at significantly higher levels both in the olfactory bulb and cortex.The dissociation between higher absolute expression levels of alpha-Synuclein but less severe impact on adult olfactory neurogenesis in mThy1 transgenic mice highlights the importance of temporal expression characteristics of alpha-Synuclein on the maturation of newborn neurons.
EVALuna2:4712

The Tip60/Ep400 chromatin remodeling complex impacts basic cellular functions in cranial neural crest-derived tissue during early orofacial development - Gehlen-Breitbach, Sebastian; Schmid, Theresa; Fröb, Franziska; Rodrian, Gabriele; Weider, Matthias; Wegner, Michael; Gölz, Lina (International Journal of Oral Science, 2023)
The cranial neural crest plays a fundamental role in orofacial development and morphogenesis. Accordingly, mutations with impact on the cranial neural crest and its development lead to orofacial malformations such as cleft lip and palate. As a pluripotent and dynamic cell population, the cranial neural crest undergoes vast transcriptional and epigenomic alterations throughout the formation of facial structures pointing to an essential role of factors regulating chromatin state or transcription levels. Using CRISPR/Cas9-guided genome editing and conditional mutagenesis in the mouse, we here show that inactivation of Kat5 or Ep400 as the two essential enzymatic subunits of the Tip60/Ep400 chromatin remodeling complex severely affects carbohydrate and amino acid metabolism in cranial neural crest cells. The resulting decrease in protein synthesis, proliferation and survival leads to a drastic reduction of cranial neural crest cells early in fetal development and a loss of most facial structures in the absence of either protein. Following heterozygous loss of Kat5 in neural crest cells palatogenesis was impaired. These findings point to a decisive role of the Tip60/Ep400 chromatin remodeling complex in facial morphogenesis and lead us to conclude that the orofacial clefting observed in patients with heterozygous KAT5 missense mutations is at least in part due to disturbances in the cranial neural crest.
CRIS-Team Scopus Importer:2023-04-21

The transcriptional co-activator Yap1 promotes adult hippocampal neural stem cell activation - Fan, Wenqiang; Jurado-Arjona, Jerónimo; Alanis-Lobato, Gregorio; Péron, Sophie; Berger, Christian; Andrade-Navarro, Miguel A.; Falk, Sven; Berninger, Benedikt (EMBO Journal, 2023)
Most adult hippocampal neural stem cells (NSCs) remain quiescent, with only a minor portion undergoing active proliferation and neurogenesis. The molecular mechanisms that trigger the transition from quiescence to activation are still poorly understood. Here, we found the activity of the transcriptional co-activator Yap1 to be enriched in active NSCs. Genetic deletion of Yap1 led to a significant reduction in the relative proportion of active NSCs, supporting a physiological role of Yap1 in regulating the transition from quiescence to activation. Overexpression of wild-type Yap1 in adult NSCs did not induce NSC activation, suggesting tight upstream control mechanisms, but overexpression of a gain-of-function mutant (Yap1-5SA) elicited cell cycle entry in NSCs and hilar astrocytes. Consistent with a role of Yap1 in NSC activation, single cell RNA sequencing revealed a partial induction of an activated NSC gene expression program. Furthermore, Yap1-5SA expression also induced expression of Taz and other key components of the Yap/Taz regulon that were previously identified in glioblastoma stem cell-like cells. Consequently, dysregulated Yap1 activity led to repression of hippocampal neurogenesis, aberrant cell differentiation, and partial acquisition of a glioblastoma stem cell-like signature.
CRIS-Team Scopus Importer:2023-05-05
Keywords: hippocampus; neurogenesis; quiescence; radial glia; single cell RNA sequencing

The Transcription Factor Encyclopedia. - Wegner, Michael; et al. (Genome Biology, 2012)
Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130 mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written and vetted by experts in the field. TFe is available at http://www.cisreg.ca/tfe.
UnivIS-Import:2015-03-09:Pub.2012.med.IB.LPCIPDBI.thetra

The transcription factor prospero homeobox protein 1 is a direct target of SoxC proteins during developmental vertebrate neurogenesis - Jacob, Anne; Wüst, Hannah; Thalhammer, Johannes; Fröb, Franziska; Küspert, Melanie; Reiprich, Simone; Balta, Elli-Anna; Lie, Dieter Chichung; Wegner, Michael; Sock, Elisabeth (Journal of Neurochemistry, 2018)
The high-mobility-group domain containing SoxC transcription factors Sox4 and Sox11 are expressed and required in the vertebrate central nervous system in neuronal precursors and neuroblasts. To identify genes that are widely regulated by SoxC proteins during vertebrate neurogenesis we generated expression profiles from developing mouse brain and chicken neural tube with reduced SoxC expression and found the transcription factor prospero homeobox protein 1 (Prox1) strongly down-regulated under both conditions. This led us to hypothesize that Prox1 expression depends on SoxC proteins in the developing central nervous system of mouse and chicken. By combining luciferase reporter assays and over-expression in the chicken neural tube with in vivo and in vitro binding studies, we identify the Prox1 gene promoter and two upstream enhancers at -44 kb and -40 kb relative to the transcription start as regulatory regions that are bound and activated by SoxC proteins. This argues that Prox1 is a direct target gene of SoxC proteins during neurogenesis. Electroporations in the chicken neural tube furthermore show that Prox1 activates a subset of SoxC target genes, whereas it has no effects on others. We propose that the transcriptional control of Prox1 by SoxC proteins may ensure coupling of two types of transcription factors that are both required during early neurogenesis, but have at least in part distinct functions. Open Data: Materials are available on https://cos.io/our-services/open-science-badges/ https://osf.io/93n6m/.
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The transcription factor Sox10 is a key regulator of peripheral glial development - Wegner, Michael; et al. (Genes & Development, 2001)
The molecular mechanisms that determine glial cell fate in the vertebrate nervous system have not been elucidated. Peripheral glial cells differentiate from pluripotent neural crest cells. We show here that the transcription factor Sox10 is a key regulator in differentiation of peripheral glial cells. In mice that carry a spontaneous or a targeted mutation of Sox10, neuronal cells form in dorsal root ganglia, hut Schwann cells or satellite cells are not generated. At later developmental stages, this lack of peripheral glial cells results in a severe degeneration of sensory and motor neurons. Moreover, we show that Sox10 controls expression of ErbB3 in neural crest cells. ErbB3 encodes a Neuregulin receptor, and down-regulation of ErbB3 accounts for many changes in development of neural crest cells observed in Sox10 mutant mice. Sox10 also has functions not mediated by ErbB3, for instance in the melanocyte lineage. Phenotypes observed in heterozygous mice that carry a targeted Sox10 null allele reproduce those observed in heterozygous Sox10Dom mice. Haploinsufficiency of Sox10 can thus cause pigmentation and megacolon defects, which are also observed in Sox10Dom/+ mice and in patients with Waardenburg-Hirschsprung disease caused by heterozygous SOX10 mutations.
UnivIS-Import:2015-03-09:Pub.2001.med.IB.LPCIPDBI.thetra
Keywords: ErbB3; Glial cells; Melanocytes; Neural crest; Neuregulin; Sox10

The transcription factor Sox10 is an essential determinant of branching morphogenesis and involution in the mouse mammary gland - Mertelmeyer, Svenja; Weider, Matthias; Baroti, Tina; Reiprich, Simone; Fröb, Franziska; Stolt, Claus; Wagner, Kay Uwe; Wegner, Michael (Scientific Reports, 2020)
The high mobility group-domain containing transcription factor Sox10 is an essential regulator of developmental processes and homeostasis in the neural crest, several neural crest-derived lineages and myelinating glia. Recent studies have also implicated Sox10 as an important factor in mammary stem and precursor cells. Here we employ a series of mouse mutants with constitutive and conditional Sox10 deficiencies to show that Sox10 has multiple functions in the developing mammary gland. While there is no indication for a requirement of Sox10 in the specification of the mammary placode or descending mammary bud, it is essential for both the prenatal hormone-independent as well as the pubertal hormone-dependent branching of the mammary epithelium and for proper alveologenesis during pregnancy. It furthermore acts in a dosage-dependent manner. Sox10 also plays a role during the involution process at the end of the lactation period. Whereas its effect on epithelial branching and alveologenesis are likely causally related to its function in mammary stem and precursor cells, this is not the case for its function during involution where Sox10 seems to work at least in part through regulation of the miR-424(322)/503 cluster.
CRIS-Team Scopus Importer:2020-10-30

The transcription factor Sox5 modulates Sox10 function during melanocyte development. - Stolt, Claus; Hillgärtner, Simone; Wegner, Michael; et al. (Nucleic Acids Research, 2008)
The transcription factor Sox5 has previously been shown in chicken to be expressed in early neural crest cells and neural crest-derived peripheral glia. Here, we show in mouse that Sox5 expression also continues after neural crest specification in the melanocyte lineage. Despite its continued expression, Sox5 has little impact on melanocyte development on its own as generation of melanoblasts and melanocytes is unaltered in Sox5-deficient mice. Loss of Sox5, however, partially rescued the strongly reduced melanoblast generation and marker gene expression in Sox10 heterozygous mice arguing that Sox5 functions in the melanocyte lineage by modulating Sox10 activity. This modulatory activity involved Sox5 binding and recruitment of CtBP2 and HDAC1 to the regulatory regions of melanocytic Sox10 target genes and direct inhibition of Sox10-dependent promoter activation. Both binding site competition and recruitment of corepressors thus help Sox5 to modulate the activity of Sox10 in the melanocyte lineage.
UnivIS-Import:2015-03-09:Pub.2008.med.IB.LPCIPDBI.thetra

The transcription factors Sox10 and Myrf define an essential regulatory network module in differentiating oligodendrocytes - Hornig, Julia; Fröb, Franziska; Vogl, Michael; Hermans-Borgmeyer, Irm; Tamm, Ernst R.; Wegner, Michael (PLoS Genetics, 2013)
Myelin is essential for rapid saltatory conduction and is produced by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. In both cell types the transcription factor Sox10 is an essential component of the myelin-specific regulatory network. Here we identify Myrf as an oligodendrocyte-specific target of Sox10 and map a Sox10 responsive enhancer to an evolutionarily conserved element in intron 1 of the Myrf gene. Once induced, Myrf cooperates with Sox10 to implement the myelination program as evident from the physical interaction between both proteins and the synergistic activation of several myelin-specific genes. This is strongly reminiscent of the situation in Schwann cells where Sox10 first induces and then cooperates with Krox20 during myelination. Our analyses indicate that the regulatory network for myelination in oligodendrocytes is organized along similar general principles as the one in Schwann cells, but is differentially implemented.
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The trick of the tail: protein-protein interactions of metabotropic glutamate receptors. - Enz, Ralf (Bioessays, 2007)
It was initially believed that G-protein-coupled receptors, such as metabotropic glutamate receptors, could simply be described as individual proteins that are associated with intracellular signal cascades via G-proteins. This view is no longer tenable. Today we know that metabotropic glutamate receptors (mGluRs) can dimerize and bind to a variety of proteins in addition to trimeric G-proteins. These newly identified protein interactions led to the discovery of new regulatory mechanisms that are independent of and sometimes synergistic with the classical G-protein-coupled second messenger pathways. Notably, several of these mechanisms connect mGluR-mediated signaling to other receptor classes, thereby creating a network of different receptor types and associated signal cascades. The intracellular C-termini of mGluRs play a key role in the regulation of these networks, and various new protein interactions of these domains were described recently. Because mGluRs are involved in a variety of physiological and pathophysiological processes, some of the proteins interacting with this receptor class have potential as valuable pharmaceutical targets. This review will give a comprehensive overview of proteins interacting with mGluR C-termini, highlight new evolving regulatory mechanisms for glutamatergic signal transduction and discuss possibilities for future drug development. © 2006 Wiley Periodicals, Inc.
UnivIS-Import:2017-12-18:Pub.2007.med.IB.profes_1.thetri

Three-step test system for the identification of novel GABAa receptor modulating food plants - Sahin, Sümeyye; Eulenburg, Volker; Kreis, Wolfgang; Villmann, Carmen; Pischetsrieder, Monika (Plant Foods For Human Nutrition, 2016)
Potentiation of γ-amino butyric acid (GABA)-induced GABAA receptor (GABAAR) activation is a common pathway to achieve sedative, sleep-enhancing, anxiolytic, and antidepressant effects. Presently, a three-component test system was established for the identification of novel GABAAR modulating food plants. In the first step, potentiation of GABA-induced response of the GABAAR was analysed by two-electrode voltage clamp (TEVC) for activity on human α1β2-GABAAR expressed in Xenopus laevis oocytes. Positively tested food plants were then subjected to quantification of GABA content by high-performance liquid chromatography with fluorescence detection (HPLC–FLD) to exclude test foods, which evoke a TEVC-response by endogenous GABA. In the third step, specificity of GABAA-modulating activity was assessed by TEVC analysis of Xenopus laevis oocytes expressing the homologous glycine receptor (GlyR). The three-component test was then applied to screen 10 aqueous extracts of food plants for their GABAAR activity. Thus, hop cones (Humulus lupulus) and Sideritis sipylea were identified as the most potent specific GABAAR modulators eliciting significant potentiation of the current by 182 ± 27 and 172 ± 19 %, respectively, at the lowest concentration of 0.5 μg/mL. The extracts can now be further evaluated by in vivo studies and by structural evaluation of the active components.
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Keywords: GABAA receptor; GABA; Glycine receptor; Sideritis; Lemon balm leaves; Hop cones

Thymosin ?4: a multi-functional regenerative peptide. Basic properties and clinical applications - Goldstein, Allan L.; Hannappel, Ewald; Sosne, Gabriel; Kleinman, Hynda K. (Expert Opinion on Biological Therapy, 2012)
INTRODUCTION: Thymosin ?(4), a low molecular weight, naturally-occurring peptide plays a vital role in the repair and regeneration of injured cells and tissues. After injury, thymosin ?(4), is released by platelets, macrophages and many other cell types to protect cells and tissues from further damage and reduce apoptosis, inflammation and microbial growth. Thymosin ?(4) binds to actin and promotes cell migration, including the mobilization, migration, and differentiation of stem/progenitor cells, which form new blood vessels and regenerate the tissue. Thymosin ?(4) also decreases the number of myofibroblasts in wounds, resulting in decreased scar formation and fibrosis. AREAS COVERED: This article will cover the many thymosin ?(4) activities that directly affect the repair and regeneration cascade with emphasis on its therapeutic uses and potential. Our approach has been to evaluate the basic biology of the molecule as well as its potential for clinical applications in the skin, eye, heart and brain. EXPERT OPINION: The considerable advances in our understanding of the functional biology and mechanisms of action of thymosin ?(4) have provided the scientific foundation for ongoing and projected clinical trials in the treatment of dermal wounds, corneal injuries and in the regeneration and repair of heart and CNS tissue following ischemic insults and trauma.
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Thymosin ?4 and tissue transglutaminase. Molecular characterization of cyclic thymosin ?4 - App, Christine; Knop, Jana; Huff, Thomas; Sticht, Heinrich; Hannappel, Ewald (Protein Journal, 2013)
Thymosin ?4 is the prototype of ?-thymosins and is present in almost every mammalian cell. It is regarded to be the main intracellular G-actin sequestering peptide. Thymosin ?4 serves as a specific glutaminyl substrate for guinea pig transglutaminase. In the absence of an appropriate additional aminyl donor an ?-amino group of thymosin ?4 serves also as an aminyl substrate and an intramolecular bond is formed concomitantly NH3 (17 Da) is lost. The molecular mass of the product is 4,949.6 Da. This is 16.3 Da less than the molecular mass of thymosin ?4 (4,965.9 Da). Digestion with endopeptidases and Edman degradation of the fragments identified the exact position of the ring forming isopeptide bond. In spite of 3 glutaminyl and 9 lysyl residues of thymosin ?4 only one isopeptide bond between Lys16 and Gln36 was formed (cyclic thymosin ?4). These two amino acid residues are conserved in all ?-thymosins. Cyclic thymosin ?4 still forms a complex with G-actin albeit the stability of the complex is about one fiftieth of the stability of the thymosin ?4 × G-actin complex.
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Thymosin beta4 inhibits ADF/cofilin stimulated F-actin cycling and hela cell migration: Reversal by active Arp2/3 complex - Al Haj, Abdulatif; Mazur, Antonina Joanna; Buchmeier, Sabine; App, Christine; Theiss, Carsten; Silvan, Unai; Schoenenberger, Cora-Ann; Jockusch, Brigitte M.; Hannappel, Ewald; Weeds, Alan G.; Mannherz, Hans Georg (Cytoskeleton, 2014)
F-actin treadmilling plays a key part in cell locomotion. Because immunofluorescence showed colocalisation of thymosin beta4 (T?4) with cofilin-1 and Arp2/3 complex in lamellipodia, we analyzed combinations of these proteins on F-actin-adenosine triphosphate (ATP)-hydrolysis, which provides a measure of actin treadmilling. Actin depolymerising factor (ADF)/cofilin stimulated treadmilling, while T?4 decreased treadmilling, presumably by sequestering monomers. T?4 added together with ADF/cofilin also inhibited the treadmilling, relative to cofilin alone, but both the rate and extent of depolymerization were markedly enhanced in the presence of both these proteins. Arp2/3 complex reversed the sequestering activity of T?4 when equimolar to actin, but not in the additional presence of cofilin-1 or ADF. Transfection experiments to explore the effects of changing the intracellular concentration of T?4 in HeLa cells showed that an increase in T?4 resulted in reduced actin filaments bundles and narrower lamellipodia, and a conspicuous decrease of cell migration as seen by two different assays. In contrast, cells transfected with a vector leading to T?4 knockdown by small interfering RNA (siRNA) displayed prominent actin filament networks within the lamellipodia and the leading lamella and enhanced migration. The experiments reported here demonstrate the importance of the interplay of these different classes of actin-binding proteins on cell behaviour. © 2013 Wiley Periodicals, Inc.
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Thymosin β4 Is an Endogenous Iron Chelator and Molecular Switcher of Ferroptosis - Lachowicz, Joanna I.; Pichiri, Giusi; Piludu, Marco; Fais, Sara; Orrù, Germano; Congiu, Terenzio; Piras, Monica; Faa, Gavino; Fanni, Daniela; Torre, Gabriele Dalla; Lopez, Xabier; Chandra, Kousik; et al. (International Journal of Molecular Sciences, 2022)
Thymosin β4 (Tβ4) was extracted forty years agofrom calf thymus. Since then, it has been identified as a G‐actin binding protein involved in blood clotting, tissue regeneration, angiogenesis, and anti‐inflammatory processes. Tβ4 has also been implicated in tumor metastasis and neuro-degeneration. However, the precise roles and mechanism(s) of action of Tβ4 in these processes re-main largely unknown, with the binding of the G‐actin protein being insufficient to explain these multi‐actions. Here we identify for the first time the important role of Tβ4 mechanism in ferroptosis, an iron‐dependent form of cell death, which leads to neurodegeneration and somehow protects cancer cells against cell death. Specifically, we demonstrate four iron2+ and iron3+ binding regions along the peptide and show that the presence of Tβ4 in cell growing medium inhibits erastin and glutamate‐induced ferroptosis in the macrophage cell line. Moreover, Tβ4 increases the expression of oxidative stress‐related genes, namely BAX, hem oxygenase‐1, heat shock protein 70 and thiore-doxin reductase 1, which are downregulated during ferroptosis. We state the hypothesis that Tβ4 is an endogenous iron chelator and take part in iron homeostasis in the ferroptosis process. We discuss the literature data of parallel involvement of Tβ4 and ferroptosis in different human pathologies, mainly cancer and neurodegeneration. Our findings confronted with literature data show that con-trolled Tβ4 release could command on/off switching of ferroptosis and may provide novel therapeutic opportunities in cancer and tissue degeneration pathologies.
CRIS-Team Scopus Importer:2022-01-14
Keywords: Ferroptosis; Metal chelation; Molecular dynamics; MRNA; NMR; TEM; Thymosine beta 4l

THz Detection of Biomolecules in Aqueous Environments-Status and Perspectives for Analysis Under Physiological Conditions and Clinical use - Weisenstein, Christian; Wigger, Anna Katharina; Richter, Merle; Sczech, Robert; Boßerhoff, Anja Katrin; Bolivar, Peter Haring (Journal of Infrared, Millimeter, and Terahertz Waves, 2021)
Bioanalytical THz sensing techniques have proven to be an interesting and viable tool for the label-free detection and analysis of biomolecules. However, a major challenge for THz bioanalytics is to perform investigations in the native aqueous environments of the analytes. This review recapitulates the status and future requirements for establishing THz biosensing as a complementary toolbox in the repertoire of standard bioanalytic methods. The potential use in medical research and clinical diagnosis is discussed. Under these considerations, this article presents a comprehensive categorization of biochemically relevant analytes that have been investigated by THz sensing techniques in aqueous media. The detectable concentration levels of ions, carbohydrates, (poly-)nucleotides, active agents, proteins and different biomacromolecules from THz experiments are compared to characteristic physiological concentrations and lower detection limits of state-of-the-art bioanalytical methods. Finally, recent experimental developments and achievements are discussed, which potentially pave the way for THz analysis of biomolecules under clinically relevant conditions.
CRIS-Team WoS Importer:2021-06-18

Tideglusib Rescues Neurite Pathology of SPG11 iPSC Derived Cortical Neurons. - Pozner, Tatyana; Schray, Annika; Regensburger, Martin; Lie, Dieter Chichung; Schlötzer-Schrehardt, Ursula; Winkler, Jürgen; Turan, Sören; Winner, Beate (Frontiers in Neuroscience, 2018)
Mutations in SPG11 cause a complicated autosomal recessive form of hereditary spastic paraplegia (HSP). Mechanistically, there are indications for the dysregulation of the GSK3 beta/beta Cat signaling pathway in SPG11. In this study, we tested the therapeutic potential of the GSK3 beta inhibitor, tideglusib, to rescue neurodegeneration associated characteristics in an induced pluripotent stem cells (iPSCs) derived neuronal model from SPG11 patients and matched healthy controls as well as a CRISPR-Cas9 mediated SPG11 knock-out line and respective control. SPG11-iPSC derived cortical neurons, as well as the genome edited neurons exhibited shorter and less complex neurites than controls. Administration of tideglusib to these lines led to the rescue of neuritic impairments. Moreover, the treatment restored increased cell death and ameliorated the membranous inclusions in iPSC derived SPG11 neurons. Our results provide a first evidence for the rescue of neurite pathology in SPG11-HSP by tideglusib. The current lack of disease-modifying treatments for SPG11 and related types of complicated HSP renders tideglusib a candidate compound for future clinical application.
EVALuna2:35778
Keywords: CRISPR knock-out; GSK3β inhibitor; SPG11; hereditary spastic paraplegia; induced pluripotent stem cell; neuronal culture; tideglusib

Toll-like Receptor 5 Activation by the CagY Repeat Domains of Helicobacter pylori - Tegtmeyer, Nicole; Neddermann, Matthias; Lind, Judith; Suneesh Kumar, Pachathundikandi; Sharafutdinov, Irshad; Gutiérrez-Escobar, Andrés Julián; Brönstrup, Mark; Tegge, Werner; Hong, Minsun; Rohde, Manfred; Delahay, Robin M.; Sticht, Heinrich; et al. (Cell Reports, 2020)
Helicobacter pylori (Hp) is an important human pathogen associated with gastric inflammation and neoplasia. It is commonly believed that this bacterium avoids major immune recognition by Toll-like receptors (TLRs) because of low intrinsic activity of its flagellin and lipopolysaccharides (LPS). In particular, TLR5 specifically detects flagellins in various bacterial pathogens, while Hp evolved mutations in flagellin to evade detection through TLR5. Cancerogenic Hp strains encode a type IV secretion system (T4SS). The T4SS core component and pilus-associated protein CagY, a large VirB10 ortholog, drives effector molecule translocation. Here, we identify CagY as a flagellin-independent TLR5 agonist. We detect five TLR5 interaction sites, promoting binding of CagY-positive Hp to TLR5-expressing cells, TLR5 stimulation, and intracellular signal transduction. Consequently, CagY constitutes a remarkable VirB10 member detected by TLR5, driving crucial innate immune responses by this human pathogen.
CRIS-Team Scopus Importer:2020-09-25
Keywords: CagY; flagellin; Helicobacter; innate and adaptive immunity; PAMP; PRR; signal transduction; T4SS; TLR5; type IV secretion

Towards a ''next generation'' neglect of diatomic differential overlap based semiempirical molecular orbital technique - Winget, Paul; Horn, Anselm; Martin, Bodo; Clark, Timothy; et al. (Theoretical Chemistry Accounts, 2003)
We discuss problems and features of current semiempirical molecular orbital techniques and test some of the approximations and assumptions used. Prerequisites for a ''next generation'' technique include orthogonalization corrections, effective core potentials and an implicit dispersion term. However, validation of experimental parameterization data using density functional theory or the Gaussian 2 approach reveals significant errors in some cases. Developers of future methods will need to validate all their parameterization data and may no longer be able to parameterize for heats of formation at 298 K, but may need to use Born-Oppenheimer binding energies. We also suggest that there is no inherent reason that semiempirical techniques should not reproduce hydrogen bonding and show that the Gaussian potentials added to the core-core terms in AM1 and the PMn methods actually weaken hydrogen bonding, rather than strengthening it.
Keywords: molecular orbital theory; modified neglect of differential overlap; MNDO/d; AM1; PM3

Towards a pro-resolving concept in systemic lupus erythematosus - Böltz, Sebastian; Hagen, Melanie; Knopf, Jasmin; Mahajan, Aparna; Schick, Maximilian; Zhao, Yi; Erfurt-Berge, Cornelia; Rech, Jürgen; Munoz Becerra, Luis; Herrmann, Martin (Seminars in Immunopathology, 2019)
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with prominent chronic inflammatory aspects. SLE most often affects women (9:1) in childbearing age. The multifactorial nature of the etiopathogenesis of SLE involves a deficient clearance of dead and dying cells. This is supported by the occurrence of autoantibodies directed against autoantigens modified in dying and dead cells (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) that are deposited in various tissues, including skin, kidneys, joints, muscles, and brain. The subsequent hyperinflammatory response often leads to irreparable tissue damage and organ destruction. In healthy individuals, dead and dying cells are rapidly removed by macrophages in an anti-inflammatory manner, referred to as efferocytosis. In SLE, extensive and prolonged cell death (apoptosis, necrosis, neutrophil extracellular trap (NET) formation) leads to autoantigens leaking out of the not cleared cell debris. These neo-epitopes are subsequently presented to B cells by follicular dendritic cells in the germinal centers of secondary lymphoid tissues conditioning the break of self-tolerance. Activation of autoreactive B cells and subsequent production of autoantibodies facilitate the formation of immune complexes (ICs) fueling the inflammatory response and leading to further tissue damage. ICs may also be ingested by phagocytes, which then produce further pro-inflammatory cytokines. These processes establish a vicious circle that leads to sustained inflammation. This review highlights the cell death–related events in SLE, the protagonists involved in SLE pathogenesis, the resolution of inflammation in various tissues affected in SLE, and explores strategies for intervention to restore hemostasis in a hyperinflammatory state.
CRIS-Team Scopus Importer:2019-11-19
Keywords: Apoptosis; Clearance; Inflammation; Neutrophil extracellular traps (NETs); Resolution; Secondary necrosis; Systemic lupus erythematosus (SLE)

Tracking micro-optical resonances for identifying and sensing novel procaspase-3 protein marker released from cell cultures in response to toxins - Chen, Ying-Jen; Xiang, Wei; Klucken, Jochen; Vollmer, Frank; Klucken, Jochen (Nanotechnology, 2016)
The response of cells to toxins is commonly investigated by detecting intracellular markers for cell death, such as caspase proteins. This requires the introduction of labels by the permeabilization or complete lysis of cells. Here we introduce a non-invasive tool for monitoring a caspase protein in the extracellular medium. The tool is based on highly sensitive optical micro-devices, referred to as whispering-gallery mode biosensors (WGMBs). WGMBs are functionalized with antibodies for the specific and label-free detection of procaspase-3 released from human embryonic kidney HEK293 and neuroglioma H4 cells after introducing staurosporine and rotenone toxins, respectively. Additional tests show that the extracellular accumulation of procaspase-3 is concomitant with a decrease in cell viability. The hitherto unknown release of procaspase-3 from cells in response to toxins and its accumulation in the medium is further investigated by Western blot, showing that the extracellular detection of procaspase-3 is interrelated with cytotoxicity of alpha-synuclein protein (aSyn) overexpressed in H4 cells. These studies provide evidence for procaspase-3 as a novel extracellular biomarker for cell death, with applications in cytotoxicity tests. Such WGMBs could be applied to further identify as-yet unknown extracellular biomarkers using established antibodies against intracellular antigens.
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Transcriptional analysis implicates endoplasmic reticulum stress in bovine spongiform encephalopathy - Tang, Yue; Xiang, Wei; Terry, Linda; Kretzschmar, Hans A.; Windl, Otto (PLoS ONE, 2010)
Bovine spongiform encephalopathy (BSE) is a fatal, transmissible, neurodegenerative disease of cattle. To date, the disease process is still poorly understood. In this study, brain tissue samples from animals naturally infected with BSE were analysed to identify differentially regulated genes using Affymetrix GeneChip Bovine Genome Arrays. A total of 230 genes were shown to be differentially regulated and many of these genes encode proteins involved in immune response, apoptosis, cell adhesion, stress response and transcription. Seventeen genes are associated with the endoplasmic reticulum (ER) and 10 of these 17 genes are involved in stress related responses including ER chaperones, Grp94 and Grp170. Western blotting analysis showed that another ER chaperone, Grp78, was up-regulated in BSE. Up-regulation of these three chaperones strongly suggests the presence of ER stress and the activation of the unfolded protein response (UPR) in BSE. The occurrence of ER stress was also supported by changes in gene expression for cytosolic proteins, such as the chaperone pair of Hsp70 and DnaJ. Many genes associated with the ubiquitin-proteasome pathway and the autophagy-lysosome system were differentially regulated, indicating that both pathways might be activated in response to ER stress. A model is presented to explain the mechanisms of prion neurotoxicity using these ER stress related responses. Clustering analysis showed that the differently regulated genes found from the naturally infected BSE cases could be used to predict the infectious status of the samples experimentally infected with BSE from the previous study and vice versa. Proof-of-principle gene expression biomarkers were found to represent BSE using 10 genes with 94% sensitivity and 87% specificity. © 2010 Tang et al.
CRIS-Team Scopus Importer:2021-08-17

Transcriptional control in myelinating glia: flavors and spices - Wegner, Michael (Glia, 2000)
Transcriptional control in myelinating glia is often described in terms of a handful of trans-acting proteins with preferential expression in these cells. An equally valid approach is the identification of cis-acting elements in genes, which are specifically transcribed in myelinating glia. Regulatory regions of several myelin genes have been analyzed in transgenic animals, transient transfections and in vitro. In some cases, these studies have identified regions responsible for glial expression within the promoters or immediate upstream regions. Other myelin genes possess promoters, which simply secure basal levels of transcription, but do not contain glia-specific cis-acting elements. Promoters of myelin genes also differ strongly in other respects. They either contain a TATA-box or are TATA-less and GC-rich. They exhibit multiple transcription initiation sites or a single strong one. Binding sites for general transcription factors, such as NF-I, Sp1, and CAAT-box binding proteins, and for downstream effectors of major signaling pathways are found in them in abundance. In agreement, members of the AP-1, CREB, STAT, and NF-κB families are well-described components of the transcription machinery in myelinating glia. Together with several members of the nuclear receptor family, they are an intrinsic part of the transcriptional control in myelinating glia. (C) 2000 Wiley-Liss, Inc.
UnivIS-Import:2015-03-05:Pub.2000.med.IB.LPCIPDBI.transc

Transcriptional control in myelinating glia: from extrinsic signals to intrinsic factors and networks - Wegner, Michael (JOURNAL OF NEUROCHEMISTRY, 2019)
CRIS-Team WoS Importer:2019-08-16

Transcriptional control in myelinating glia: the basic recipe - Wegner, Michael (Glia, 2000)
Development of myelinating glia and the myelination process both require dramatic changes in the pattern of gene expression. During these processes, cells of the oligodendrocyte and Schwann cell lineages have to alter the transcription rates of numerous genes in a highly coordinated manner. This is made possible by the combined action of a set of transcription factors with preferential expression in these cells. Recent years have seen the identification of such glial transcription factors, including several homeodomain proteins, zinc finger proteins and HMG-domain proteins. Understanding their mode of action will help to unravel the molecular basis of myelination and will provide insights into the causes of myelinopathies and related diseases.
UnivIS-Import:2015-03-05:Pub.2000.med.IB.LPCIPDBI.transc_87
Keywords: Charcot-Marie-Tooth disease; Egr; Gtx; Krox; Oligodendrocyte; Pax; Pelizaeus-Merzbacher disease; POU; Schwann cell; SCIP; Sox

Transcriptional control of myelination and remyelination - Sock, Elisabeth; Wegner, Michael (Glia, 2019)
Myelination is an evolutionary recent differentiation program that has been independently acquired in vertebrates by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. Therefore, it is not surprising that regulating transcription factors differ substantially between both cell types. However, overall principles are similar as transcriptional control in Schwann cells and oligodendrocytes combines lineage determining and stage-specific factors in complex regulatory networks. Myelination does not only occur during development, but also as remyelination in the adult. In line with the different conditions during developmental myelination and remyelination and the distinctive properties of Schwann cells and oligodendrocytes, transcriptional regulation of remyelination exhibits unique features and differs between the two cell types. This review gives an overview of the current state in the field.
CRIS-Team Scopus Importer:2019-05-14
Keywords: developmental regulation; glia; myelin; oligodendrocyte; regulatory circuit; Schwann cell

Transcription-Factor-Dependent Control of Adult Hippocampal Neurogenesis - Beckervordersandforth, Ruth; Zhang, Chun-Li; Lie, Dieter Chichung (Cold Spring Harbor Perspectives in Biology, 2015)
Adult-generated dentate granule neurons have emerged as major contributors to hippocampal plasticity. New neurons are generated from neural stem cells through a complex sequence of proliferation, differentiation, and maturation steps. Development of the new neuron is dependent on the precise temporal activity of transcription factors, which coordinate the expression of stage-specific genetic programs. Here, we review current knowledge in transcription factor-mediated regulation of mammalian neural stem cells and neurogenesis and will discuss potential mechanisms of how transcription factor networks, on one hand, allow for precise execution of the developmental sequence and, on the other hand, allow for adaptation of the rate and timing of adult neurogenesis in response to complex stimuli. Understanding transcription factor-mediated control of neuronal development will provide new insights into the mechanisms underlying neurogenesis-dependent plasticity in health and disease.
EVALuna2:26328

Transcription factor profiling identifies Sox9 as regulator of proliferation and differentiation in corneal epithelial stem/progenitor cells - Menzel-Severing, Johannes; Zenkel, Matthias; Polisetti, Naresh; Sock, Elisabeth; Wegner, Michael; Kruse, Friedrich; Schlötzer-Schrehardt, Ursula (Scientific Reports, 2018)
Understanding transcription factor (TF) regulation of limbal epithelial stem/progenitor cells (LEPCs) may aid in using non-ocular cells to regenerate the corneal surface. This study aimed to identify and characterize TF genes expressed specifically in LEPCs isolated from human donor eyes by laser capture microdissection. Using a profiling approach, preferential limbal expression was found for SoxE and SoxF genes, particularly for Sox9, which showed predominantly cytoplasmic localization in basal LEPCs and nuclear localization in suprabasal and corneal epithelial cells, indicating nucleocytoplasmic translocation and activation during LEPC proliferation and differentiation. Increased nuclear localization of Sox9 was also observed in activated LEPCs following clonal expansion and corneal epithelial wound healing. Knockdown of SOX9 expression in cultured LEPCs by RNAi led to reduced expression of progenitor cell markers, e.g. keratin 15, and increased expression of differentiation markers, e.g. keratin 3. Furthermore, SOX9 silencing significantly suppressed the proliferative capacity of LEPCs and reduced levels of glycogen synthase kinase 3 beta (GSK-3ß), a negative regulator of Wnt/ß-catenin signaling. Sox9 expression, in turn, was significantly suppressed by treatment of LEPCs with exogenous GSK-3ß inhibitors and enhanced by small molecule inhibitors of Wnt signaling. Our results suggest that Sox9 and Wnt/ß-catenin signaling cooperate in mutually repressive interactions to achieve a balance between quiescence, proliferation and differentiation of LEPCs in the limbal niche. Future molecular dissection of Sox9-Wnt interaction and mechanisms of nucleocytoplasmic shuttling of Sox9 may aid in improving the regenerative potential of LEPCs and the reprogramming of non-ocular cells for corneal surface regeneration.
EVALuna2:34733

Transcription factor Sox10 induces the microRNAs miR-335, miR-338 and miR-155 to ensure correct timing of oligodendrocyte development - Küspert, Melanie; Reiprich, Simone; Cantone, Martina; Weider, Matthias; Baroti, Tina; Wittstatt, Jan; Vera, Julio; Wegner, Michael (GLIA, 2019)
CRIS-Team WoS Importer:2020-01-10

Transcription factor Sox10 orchestrates activity of a neural crest-specific enhancer in the vicinity of its gene. - Reiprich, Simone; Wegner, Michael; et al. (Nucleic Acids Research, 2012)
The Sox10 transcription factor is a central regulator of vertebrate neural crest and nervous system development. Its expression is likely controlled by multiple enhancer elements, among them U3 (alternatively known as MCS4). Here we analyze U3 activity to obtain deeper insights into Sox10 function and expression in the neural crest and its derivatives. U3 activity strongly depends on the presence of Sox10 that regulates its own expression as commonly observed for important developmental regulators. Sox10 bound directly as monomer to at least three sites in U3, whereas a fourth site preferred dimers. Deletion of these sites efficiently reduced U3 activity in transfected cells and transgenic mice. In stimulating the U3 enhancer, Sox10 synergized with many other transcription factors present in neural crest and developing peripheral nervous system including Pax3, FoxD3, AP2α, Krox20 and Sox2. In case of FoxD3, synergism involved Sox10-dependent recruitment to the U3 enhancer, while Sox10 and AP2α each had to bind to the regulatory region. Our study points to the importance of autoregulatory activity and synergistic interactions for maintenance of Sox10 expression and functional activity of Sox10 in the neural crest regulatory network. © 2011 The Author(s).
UnivIS-Import:2015-03-09:Pub.2012.med.IB.LPCIPDBI.transc

Transcription factor Sox10 regulates oligodendroglial Sox9 levels via microRNAs. - Reiprich, Simone; Cantone, Martina; Weider, Matthias; Baroti, Tina; Wittstatt, Jan; Schmitt, Christian; Küspert, Melanie; Vera, Julio; Wegner, Michael (Glia, 2017)
During development of myelin-forming oligodendrocytes in the central nervous system the two closely related transcription factors Sox9 and Sox10 play essential roles that are partly shared and partly unique. Whereas Sox9 primarily functions during oligodendroglial specification, Sox10 is uniquely required to induce terminal differentiation and myelination. During this process, Sox10 protein levels rise substantially. As this coincides with a reciprocal decrease in Sox9, we postulated that Sox10 influences Sox9 amounts in differentiating oligodendrocytes. Here we show that Sox9 levels are indeed inversely coupled to Sox10 levels such that Sox10 deletion in oligodendroglial cells evokes a reciprocal increase in Sox9. We furthermore provide evidence that this coupling involves upregulation of microRNAs miR335 and miR338 as direct transcriptional targets of Sox10. The two microRNAs in turn recognize the 3′-UTR of Sox9 mRNA and may thereby reduce Sox9 protein levels posttranscriptionally in oligodendroglial cells. Such a mechanism may enable oligodendroglial cells to adapt the ratio of both related Sox proteins in a manner required for successful lineage progression and differentiation. Mathematical modeling furthermore shows that the identified regulatory circuit has the potential to convert a transient stimulus into an irreversible switch of cellular properties and may thus contribute to terminal differentiation of oligodendrocytes.
EVALuna2:33479
Keywords: glia; HMG; miR338; oligodendrocyte; Sox

Transcription factors Sox10 and Sox2 functionally interact with positive transcription elongation factor b in Schwann cells - Arter, Juliane; Wegner, Michael (Journal of Neurochemistry, 2015)
Sox proteins are mechanistically versatile regulators with established relevance to different developmental processes and crucial impact on chromatin structure, DNA conformation, and transcriptional initiation. Here, we show that Sox2 and Sox10, two Sox proteins important for Schwann cell development, also have the capability to activate transcriptional elongation in a Schwann cell line by recruiting the positive transcription elongation factor b. Recruitment is mediated by physical interaction between the carboxyterminal transactivation domains of the two Sox proteins and the Cyclin T1 subunit of positive transcription elongation factor b, with interaction interfaces for the two Sox proteins being mapped to adjacent regions of the central part of Cyclin T1. Supporting the relevance of this interaction to Schwann cell development, transcription of myelin genes appears regulated at the level of elongation. Our results thus add a new facet to the activity of Sox proteins and expand the functional repertoire of this important group of developmental regulators. Sox transcription factors are important regulators of nervous system development. While they are known to regulate transcription by recruiting and stabilizing the RNA polymerase II preinitiation complex directly or with help of the Mediator complex, this study provides evidence that Sox10 and Sox2 additionally influence transcription in glial cells at the elongation stage by recruiting P-TEFb. Cdk9, cyclin-dependent kinase 9; P-TEFb, positive transcription elongation factor b; Pol II, RNA polymerase II; Sox, Sox2 or Sox10 protein.
EVALuna2:4977

Transcription factors Sox5 and Sox6 exert direct and indirect influences on oligodendroglial migration in spinal cord and forebrain - Baroti, Tina; Zimmermann, Yvonne; Schillinger, Anja; Liu, Lina; Lommes, Petra; Wegner, Michael; Stolt, Claus (Glia, 2016)
Transcription factors of the SoxD protein family have previously been shown to prevent precocious specification and terminal differentiation of oligodendrocyte progenitor cells in the developing spinal cord. Using mice with specific deletion of the SoxD proteins Sox5 and Sox6 in the central nervous system, we now show that SoxD proteins additionally influence migration of oligodendrocyte progenitors in the spinal cord as well as in the forebrain. In mutant mice, emigration of oligodendrocyte progenitors from the ventricular zone and colonization of the mantle zone are significantly delayed probably because of reduced expression of Pdgf receptor alpha and decreased responsiveness toward Pdgf-A as a main migratory cue. In addition to this direct cell-autonomous effect on Pdgf receptor alpha expression, SoxD proteins furthermore promote oligodendroglial migration by keeping the cells in an undifferentiated state and preventing a premature loss of their migratory capacity. This indirect effect becomes particularly important during late embryonic and early postnatal phases of oligodendroglial development. Finally, we show that Sox5 and Sox6 cooperate with Sox9 and Sox10 to activate Pdgf receptor alpha expression and thereby maintain oligodendrocyte progenitors in the immature state. This contrasts with their behavior on myelin genes where they antagonize the function of SoxE proteins. It argues that SoxD proteins can function either as repressors or as co-activators of SoxE proteins thereby modulating their function in a stage-specific manner.
EVALuna2:4986

Transcription factors Sox8 and Sox10 perform non-equivalent roles during oligodendrocyte development despite functional redundancy. - Wegner, Michael; Stolt, Claus; et al. (Development, 2004)
Development of myelin-forming oligodendrocytes in the central nervous system is dependent on at least two members of the Sox family of high-mobility-group-containing transcription factors. Sox9 is involved in oligodendrocyte specification, whereas Sox10 is required for terminal differentiation. We show that oligodendrocytes in the spinal cord additionally express the highly related Sox8. In Sox8-deficient mice, oligodendrocyte development proceeded normally until birth. However, terminal differentiation of oligodendrocytes was transiently delayed at early postnatal times. Sox8-deficient mice thus exhibited a similar, but less severe phenotype than did Sox10-deficient mice. Terminal oligodendrocyte differentiation was dramatically delayed in Sox8-deficient mice with only a single functional Sox10 allele hinting at redundancy between both Sox proteins. This redundancy was also evident from the fact that Sox8 bound to naturally occurring Sox10 response elements, was able to form DNA-dependent heterodimers with Sox10 and activated Sox10-specific oligodendrocytic target genes in a manner similar to Sox10. However, Sox8 expression levels were significantly lower than those for Sox10. Resulting differences in protein amounts might be a main reason for the weaker impact of Sox8 on oligodendrocyte development and for unidirectional compensation of the Sox8 loss by Sox10.
UnivIS-Import:2015-03-09:Pub.2004.med.IB.LPCIPDBI.transc
Keywords: Gene dosage; High-mobility-group; Oligodendrocyte; Redundancy; Sox10; Sry

Transcription factor Tcf4 is the preferred heterodimerization partner for Olig2 in oligodendrocytes and required for differentiation - Wedel, Miriam; Fröb, Franziska; Elsesser, Olga; Wittmann, Marie-Theres; Lie, Dieter Chichung; Reis, André; Wegner, Michael (Nucleic Acids Research, 2020)
Development of oligodendrocytes and myelin formation in the vertebrate central nervous system is under control of several basic helix-loop-helix transcription factors such as Olig2, Ascl1, Hes5 and the Id proteins. The class I basic helix-loop-helix proteins Tcf3, Tcf4 and Tcf12 represent potential heterodimerization partners and functional modulators for all, but have not been investigated in oligodendrocytes so far. Using mouse mutants, organotypic slice and primary cell cultures we here show that Tcf4 is required in a cell-autonomous manner for proper terminal differentiation and myelination in vivo and ex vivo. Partial compensation is provided by the paralogous Tcf3, but not Tcf12. On the mechanistic level Tcf4 was identified as the preferred heterodimerization partner of the central regulator of oligodendrocyte development Olig2. Both genetic studies in the mouse as well as functional studies on enhancer regions of myelin genes confirmed the relevance of this physical interaction for oligodendrocyte differentiation. Considering that alterations in TCF4 are associated with syndromic and non-syndromic forms of intellectual disability, schizophrenia and autism in humans, our findings point to the possibility of an oligodendroglial contribution to these disorders.
CRIS-Team Scopus Importer:2020-05-29

Transcription factor Zfp276 drives oligodendroglial differentiation and myelination by switching off the progenitor cell program - Aberle, Tim; Piefke, Sandra; Hillgärtner, Simone; Tamm, Ernst R.; Wegner, Michael; Küspert, Melanie (Nucleic Acids Research, 2022)
In oligodendrocytes of the vertebrate central nervous system a complex network of transcriptional regulators is required to ensure correct and timely myelination of neuronal axons. Here we identify Zfp276, the only mammalian ZAD-domain containing zinc finger protein, as a transcriptional regulator of oligodendrocyte differentiation and central myelination downstream of Sox10. In the central nervous system, Zfp276 is exclusively expressed in mature oligodendrocytes. Oligodendroglial deletion of Zfp276 led to strongly reduced expression of myelin genes in the early postnatal mouse spinal cord. Retroviral overexpression of Zfp276 in cultured oligodendrocyte precursor cells induced precocious expression of maturation markers and myelin genes, further supporting its role in oligodendroglial differentiation. On the molecular level, Zfp276 directly binds to and represses Sox10-dependent gene regulatory regions of immaturity factors and functionally interacts with the transcriptional repressor Zeb2 to enable fast transition of oligodendrocytes to the myelinating stage.
CRIS-Team Scopus Importer:2022-03-11

Transfer of htlv-1 p8 and gag to target t-cells depends on vasp, a novel interaction partner of p8 - Donhauser, Norbert; Socher, Eileen; Millen, Sebastian; Heym, Stefanie; Sticht, Heinrich; Thoma-Kreß, Andrea (PLoS Pathogens, 2020)
The Human T-cell leukemia virus type 1 (HTLV-1) orf I-encoded accessory protein p8 is cleaved from its precursor p12, and both proteins contribute to viral persistence. p8 induces cellular protrusions, which are thought to facilitate transfer of p8 to target cells and virus transmission. Host factors interacting with p8 and mediating p8 transfer are unknown. Here, we report that vasodilator-stimulated phosphoprotein (VASP), which promotes actin filament elongation, is a novel interaction partner of p8 and important for p8 and HTLV-1 Gag cell-to-cell transfer. VASP contains an Ena/VASP homology 1 (EVH1) domain that targets the protein to focal adhesions. Bioinformatics identified a short stretch in p8 (amino acids (aa) 24-45) which may mediate interactions with the EVH1 domain of VASP. Co-immunoprecipitations confirmed interactions of VASP:p8 in 293T, Jurkat and HTLV-1-infected MT-2 cells. Co-precipitation of VASP:p8 could be significantly blocked by peptides mimicking aa 26-37 of p8. Mutational studies revealed that the EVH1-domain of VASP is necessary, but not sufficient for the interaction with p8. Further, deletion of the VASP G- and F-actin binding domains significantly diminished co-precipitation of p8. Imaging identified areas of partial co-localization of VASP with p8 at the plasma membrane and in protrusive structures, which was confirmed by proximity ligation assays. Co-culture experiments revealed that p8 is transferred between Jurkat T-cells via VASP-containing conduits. Imaging and flow cytometry revealed that repression of both endogenous and overexpressed VASP by RNA interference or by CRISPR/Cas9 reduced p8 transfer to the cell surface and to target Jurkat T-cells. Stable repression of VASP by RNA interference in chronically infected MT-2 cells impaired both p8 and HTLV-1 Gag transfer to target Jurkat T-cells, while virus release was unaffected. Thus, we identified VASP as a novel interaction partner of p8, which is important for transfer of HTLV-1 p8 and Gag to target T-cells.
CRIS-Team Scopus Importer:2020-10-16

Transforming Growth Factor β-Mediated Sox10 Suppression Controls Mesenchymal Progenitor Generation in Neural Crest Stem Cells. - Wegner, Michael; et al. (Stem cells, 2011)
During vertebrate development, neural crest stem cells (NCSCs) give rise to neural cells of the peripheral nervous system and to a variety of mesenchymal cell types, including smooth muscle, craniofacial chondrocytes, and osteocytes. Consistently, mesenchymal stem cells (MSCs) have recently been shown to derive in part from the neural crest (NC), although the mechanisms underlying MSC generation remains to be identified. Here, we show that transforming growth factor β (TGFβ)-mediated suppression of the NCSC transcription factor Sox10 induces a switch in neural to mesenchymal potential in NCSCs. In vitro and in vivo, TGFβ signal inactivation results in persistent Sox10 expression, decreased cell cycle exit, and perturbed generation of mesenchymal derivatives, which eventually leads to defective morphogenesis. In contrast, TGFb-mediated downregulation of Sox10 or its genetic inactivation suppresses neural potential, confers mesenchymal potential to NC cells in vitro, and promotes cell cycle exit and precocious mesenchymal differentiation in vivo. Thus, negative regulation of Sox10 by TGFb signaling promotes the generation of mesenchymal progenitors from NCSCs. Our study might lay the grounds for future applications demanding defined populations of MSCs for regenerative medicine. © AlphaMed Press.
UnivIS-Import:2015-03-09:Pub.2011.med.IB.LPCIPDBI.transf
Keywords: Mesenchymal progenitors; Neural crest stem cell; Sox10; TGFβ

Translation of SOX10 3' untranslated region causes a complex severe neurocristopathy by generation of a deleterious functional domain. - Wegner, Michael; et al. (Human Molecular Genetics, 2007)
Peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, Waardenburg syndrome and Hirschsprung disease (PCWH) is a complex neurocristopathy caused by SOX10 mutations. Most PCWH - associated SOX10 mutations result in premature termination codons (PTCs), for which the molecular mechanism has recently been delineated. However, the first mutation reported to cause PCWH was a disruption of the native stop codon that by conceptual translation extends the protein into the 3′ untranslated region (3′-UTR) for an additional 82 residues. In this study, we sought to determine the currently unknown molecular pathology for the SOX10 extension mutation using in vitro functional assays. Despite the wild-type SOX10 coding sequence remaining intact, the extension mutation led to severely diminished transcription and DNA-binding activities. Nevertheless, it showed no dominant-negative interference with wild-type SOX10 in vitro. Within the 82-amino acid tail, an 11-amino acid region (termed the WR domain) was responsible primarily for the deleterious properties of the extension. The WR domain, presumably forming an α-helix structure, inhibited SOX10 transcription activities if inserted in the carboxyl-terminal half of the protein. The WR domain can also affect other transcription factors with a graded effect when fused to the carboxyl termini, suggesting that it probably elicits a toxic functional activity. Together, molecular pathology for the SOX10 extension mutation is distinct from that of more common PTC mutations. Failure to properly terminate SOX10 translation causes the generation of a deleterious functional domain that occurs because of translation of the normal 3′-UTR; the mutant fusion protein causes a severe neurological disease. © The Author 2007. Published by Oxford University Press. All rights reserved.
UnivIS-Import:2015-03-09:Pub.2007.med.IB.LPCIPDBI.transl

Transport activities and expression patterns of glycine transporters 1 and 2 in the developing murine brain stem and spinal cord - Lall, Deepti; Armbruster, Anja; Ruffert, Karelia; Betz, Heinrich; Eulenburg, Volker (Biochemical and Biophysical Research Communications, 2012)
Glycine serves as a neurotransmitter in spinal cord and brain stem, where it activates inhibitory glycine receptors. In addition, it serves as an essential co-agonist of excitatory N-methyl-d-aspartate receptors. In the central nervous system, extracellular glycine concentrations are regulated by two specific glycine transporters (GlyTs), GlyT1 and GlyT2. Here, we determined the relative transport activities and protein levels of GlyT1 and GlyT2 in membrane preparations from mouse brain stem and spinal cord at different developmental stages. We report that early postnatally (up to postnatal day P5) GlyT1 is the predominant transporter isoform responsible for a major fraction of the GlyT-mediated [(3)H]glycine uptake. At later stages (>>= P10), however, the transport activity and expression of GlyT2 increases, and in membrane fractions from adult mice both GlyTs contribute about equally to glycine uptake. These alterations in the activities and expression profiles of the GlyTs suggest that the contributions of GlyT1 and GlyT2 to the regulation of extracellular glycine concentrations at glycinergic synapses changes during development.
EVALuna2:4678

Treadmill exercise intervention improves gait and postural control in alpha-synuclein mouse models without inducing cerebral autophagy - Minakaki, Georgia; Canneva, Fabio; Chevessier, Frederic; Bode, Frederik; Menges, Stefanie; Timotius, Ivanna; Kalinichenko, Liubov; Meixner, Holger; Müller, Christian P.; Eskofier, Björn; Casadei, Nicolas; Riess, Olaf; et al. (Behavioural Brain Research, 2019)
Gait and postural control dysfunction are prototypical symptoms compromising quality of life for patients with Parkinson’s disease (PD). Hallmarks of cellular pathology are dopaminergic degeneration and accumulation of the cytosolic protein alpha-synuclein, linked to impaired autophagy-lysosome pathway (ALP) clearance. Physical exercise improves gait in PD patients and motor function in rodent lesion models. Moreover, exercise is considered neuroprotective and ALP induction has been reported, e.g. in human skeletal muscle, rodent peripheral and cerebral tissues. A combined analysis of how distinct exercise paradigms affect motor and central biochemical aspects of PD could maximize benefits for patients. Here we examine the effect of 4 weeks treadmill exercise intervention in 7-8 month non-lesioned mice on a) distinct gait categories, b) ALP activity, c) dopaminergic and alpha-synuclein homeostasis. The study includes wild type, alpha-synuclein knockout, and mice exclusively expressing human alpha-synuclein. Parameters of gait regularity and stability, activity, and dynamic postural control during unforced walk, were assessed by an automated system (CatWalk XT). At baseline, alpha-synuclein mouse models exhibited irregular and less active gait, with impaired dynamic postural control, compared to wild type mice. Treadmill exercise particularly improved speed and stride length, while increasing dual diagonal versus three-paw body support in both the alpha-synuclein knockout and transgenic mice. Biochemical analyses showed higher striatal tyrosine hydroxylase immuno-reactivity and reduced higher-order alpha-synuclein species in the cerebral cortex. However, no significant cerebral ALP induction was measured. In summary, treadmill exercise improved gait activity and postural stability, and promoted dopaminergic and alpha-synuclein homeostasis, without robustly inducing cerebral ALP.<br
Keywords: alpha-synuclein; autophagy; instrumented gait analysis; mouse gait pattern; Parkinson´s disease; treadmill exercise

Trimer stability of Helicobacter pylori HtrA is regulated by a natural mutation in the protease domain - Zarzecka, Urszula; Tegtmeyer, Nicole; Sticht, Heinrich; Backert, Steffen (Medical Microbiology and Immunology, 2023)
The human pathogen Helicobacter pylori is a major risk factor for gastric disease development. Serine protease HtrA is an important bacterial virulence factor that cleaves the cell junction proteins occludin, claudin-8 and E-cadherin, which causes gastric tissue damage. Using casein zymography, we discovered that HtrA trimer stability varies in clinical H. pylori strains. Subsequent sequence analyses revealed that HtrA trimer stability correlated with the presence of leucine or serine residue at position 171. The importance of these amino acids in determining trimer stability was confirmed by leucine-to-serine swapping experiments using isogenic H. pylori mutant strains as well as recombinant HtrA proteins. In addition, this sequence position displays a high sequence variability among various bacterial species, but generally exhibits a preference for hydrophilic amino acids. This natural L/S171 polymorphism in H. pylori may affect the protease activity of HtrA during infection, which could be of clinical importance and may determine gastric disease development.
CRIS-Team Scopus Importer:2023-05-26
Keywords: Helicobacter pylori; HtrA; Proteases; Trimer stability

Tumor Cells Develop Defined Cellular Phenotypes After 3D-Bioprinting in Different Bioinks - Schmidt, Sonja; Schmid, Rafael; Arkudas, Andreas; Kengelbach-Weigand, Annika; Boßerhoff, Anja Katrin (Cells, 2019)
Malignant melanoma is often used as a model tumor for the establishment of novel therapies. It is known that two-dimensional (2D) culture methods are not sufficient to elucidate the various processes during cancer development and progression. Therefore, it is of major interest to establish defined biofabricated three-dimensional (3D) models, which help to decipher complex cellular interactions. To get an impression of their printability and subsequent behavior, we printed fluorescently labeled melanoma cell lines with Matrigel and two different types of commercially available bioinks, without or with modification (RGD (Arginine-Glycine-Aspartate)-sequence/laminin-mixture) for increased cell-matrix communication. In general, we demonstrated the printability of melanoma cells in all tested biomaterials and survival of the printed cells throughout 14 days of cultivation. Melanoma cell lines revealed specific differential behavior in the respective inks. Whereas in Matrigel, the cells were able to spread, proliferate and form dense networks throughout the construct, the cells showed no proliferation at all in alginate-based bioink. In gelatin methacrylate-based bioink, the cells proliferated in clusters. Surprisingly, the modifications of the bioinks with RGD or the laminin blend did not affect the analyzed cellular behavior. Our results underline the importance of precisely adapting extracellular matrices to individual requirements of specific 3D bioprinting applications.
CRIS-Team WoS Importer:2019-11-29

Two novel CreERT2 transgenic mouse lines to study melanocytic cells in vivo - Stüfchen, Isabel; Beckervordersandforth, Ruth; Fischer, Stefan; Kappelmann-Fenzl, Melanie; Boßerhoff, Anja Katrin; Beyer, Felix (Pigment Cell & Melanoma Research, 2022)
The skin of adult mammals protects from radiation, physical and chemical insults. While melanocytes and melanocyte-producing stem cells contribute to proper skin function in healthy organisms, dysfunction of these cells can lead to the generation of malignant melanoma—the deadliest type of skin cancer. Addressing cells of the melanocyte lineage in vivo represents a prerequisite for the understanding of melanoma on cellular level and the development of preventive and treatment strategies. Here, the inducible Cre-loxP-system has emerged as a promising tool to specifically target, monitor, and modulate cells in adult mice. Re-analysis of existing sequencing data sets of melanocytic cells revealed that genes with a known function in neural cells, including neural stem cells (Aldh1L1 and Nestin), are also expressed in melanocytic cells. Therefore, in this study, we explored whether the promoter activity of Nestin and Aldh1L1 can serve to target cells of the melanocyte lineage using the inducible CreERT2-loxP-system. Using an immunohistochemical approach and different time points of analysis, we were able to map the melanocytic fate of recombined stem cells in the adult hair follicle of Nestin-CreERT2 and Aldh1L1-CreERT2 transgenic mice. Thus, we here present two new mouse models and propose their use to study and putatively modulate adult melanocytic cells in vivo.
CRIS-Team Scopus Importer:2022-09-02
Keywords: Aldh1L1-CreER; inducible Cre mouse line; melanocyte; melanocyte stem cell; multipotent stem cell; Nestin-CreER

UBE2L3 Polymorphism Amplifies NF-?B Activation and Promotes Plasma Cell Development, Linking Linear Ubiquitination to Multiple Autoimmune Diseases - Lewis, Myles J.; Vyse, Simon; Shields, Adrian M.; Böltz, Sebastian; Gordon, Patrick A.; Spector, Timothy D.; Lehner, Paul J.; Walczak, Henning; Vyse, Timothy J. (American Journal of Human Genetics, 2015)
UBE2L3 is associated with increased susceptibility to numerous autoimmune diseases, but the underlying mechanism is unexplained. By using data from a genome-wide association study of systemic lupus erythematosus (SLE), we observed a single risk haplotype spanning UBE2L3, consistently aligned across multiple autoimmune diseases, associated with increased UBE2L3 expression in B cells and monocytes. rs140490 in the UBE2L3 promoter region showed the strongest association. UBE2L3 is an E2 ubiquitin-conjugating enzyme, specially adapted to function with HECT and RING-in-between-RING (RBR) E3 ligases, including HOIL-1 and HOIP, components of the linear ubiquitin chain assembly complex (LUBAC). Our data demonstrate that UBE2L3 is the preferred E2 conjugating enzyme for LUBAC in vivo, and UBE2L3 is essential for LUBAC-mediated activation of NF-?B. By accurately quantifying NF-?B translocation in primary human cells from healthy individuals stratified by rs140490 genotype, we observed that the autoimmune disease risk UBE2L3 genotype was correlated with basal NF-?B activation in unstimulated B cells and monocytes and regulated the sensitivity of NF-?B to CD40 stimulation in B cells and TNF stimulation in monocytes. The UBE2L3 risk allele correlated with increased circulating plasmablast and plasma cell numbers in SLE individuals, consistent with substantially elevated UBE2L3 protein levels in plasmablasts and plasma cells. These results identify key immunological consequences of the UBE2L3 autoimmune risk haplotype and highlight an important role for UBE2L3 in plasmablast and plasma cell development.
EVALuna2:13089

Ultrasensitive marker-free biomolecular THz-detection for tumor-related analytics - Richter, Merle; Loth, Yannik; Weisenstein, Christian; Wigger, Anna Katharina; Schaar, Dominik; Boßerhoff, Anja Katrin; Bolivar, Peter Haring (Frequenz, 2022)
Terahertz (THz) biosensing has emerged as an important research field, mainly driven by the resonant behavior of many biomolecules in this spectral range which holds potential for highly sensitive analyses. In this work, we present a detailed overview of our current research on THz biosensing, focusing on the development and analysis of THz biosensors based on frequency selective surfaces (FSS) for two different measurement scenarios: i) label-free, highly sensitive and selective analysis of dried biomolecules, and ii) sensitive and selective analysis in an aqueous environment. With our carefully designed THz biosensor for measurements in the dry state, we were able to indirectly measure tumor-marker MIA RNA in a concentration as low as 1.55 x 10(-12) mol/L, without the need for biochemical amplification. Our biosensor with substrate-integrated microfluidics for terahertz measurements in an aqueous environment is validated by simulations, showing that the resonance feature in the frequency response of our sensor is maintained even for measurements in water.
CRIS-Team WoS Importer:2022-11-18

Ultrasensitive THz biosensor for PCR-free cDNA detection based on frequency selective surfaces - Weisenstein, Christian; Schaar, Dominik; Wigger, Anna Katharina; Schäfer-Eberwein, Heiko; Boßerhoff, Anja Katrin; Bolívar, Peter Haring (Biomedical Optics Express, 2020)
THz technologies are a powerful tool for label-free detection of biomolecules. However, significant reduction of the lower detection limit is required to apply THz-sensors in biomedical diagnosis. This paper reports an ultrasensitive THz-biosensor based on asymmetric double split ring resonators (aDSRR) for the direct label- and PCR-free detection of DNA at physiologically relevant concentrations. We introduce selective functionalization and localized electric field concentration to enhance aDSRR sensitivity and specificity. The sensor characteristics are demonstrated using the human tumor marker MIA in cDNA samples produced from total RNA without PCR-amplification. Measurements of DNA samples with concentrations as low as 1.55 × 10−12 mol/l are presented.
CRIS-Team Scopus Importer:2020-02-14

Untangling human neurogenesis to understand and counteract brain disorders - Beckervordersandforth, Ruth; Rolando, Chiara (Current Opinion in Pharmacology, 2020)
Neurogenesis in the human postnatal brain occurs in two regions, the subventricular zone of the later ventricle and the dentate gyrus of the hippocampus. While it is well accepted that SVZ and hippocampal neurogenesis are active during juvenile stages in human, their contribution during adulthood and ageing as well as pathological states is recently animating the neural stem cell research field. In this review we will discuss recent evidence about the organization of SVZ and hippocampal neurogenic niches, and will report on how human adult neurogenesis may contribute to disease and appears to respond to neurodegeneration. In light of these novel findings, we will discuss how we can target human adult neurogenesis in order to influence brain disease trajectories.
CRIS-Team Scopus Importer:2020-01-07

Usability and Suitability of the Omics-Integrating Analysis Platform tranSMART for Translational Research and Education - Christoph, Jan; Knell, Christian; Boßerhoff, Anja Katrin; Naschberger, Elisabeth; Stürzl, Michael; Rübner, Matthias; Seuß, Hannes; Ruh, Manuel; Prokosch, Hans-Ulrich; Sedlmayr, Brita (Applied Clinical Informatics, 2017)
Platforms like tranSMART assist researchers in analyzing clinical and corresponding omics data. Usability is an important, yet often overlooked, factor affecting the adoption and meaningful use. Analyses on the specific needs of translational researchers and considerations about the application of such platforms for education are rare. The aim of this study was to test whether tranSMART can be used in education and how well medical students and professional researchers can handle it; to identify which kind of translational researchers-in terms of skills, experienced limitations, and available data-can take advantage of tranSMART; and to evaluate the usability and to generate recommendations for improvements. An online-based test has been done by medical students (N = 109) and researchers (N = 26). The test comprised 13 tasks in the context of four typical research scenarios based on experimental and clinical data. A web questionnaire was provided to identify both the needs and the conditions of research as well as to evaluate the system's usability based on the "System Usability Scale" (SUS). Students and researchers were able to handle tranSMART well and coped with most scenarios: cohort identification, data exploration, hypothesis generation, and hypothesis validation were answered with a rate of correctness between 82 and 100%. Of the total, 72.2% of the teaching researchers considered tranSMART suitable for their lessons and 84.6% of the researchers considered the platform useful for their daily work; 65.4% of the researchers named the nonavailability of a platform like tranSMART as a restriction on their research. The usability was rated "acceptable" with a SUS of 70.8. tranSMART is potentially suitable for education purposes and fits most of the needs of translational researchers. Improvements are needed on the presentation of analysis results and on the guidance of users through the analysis, especially to ensure the compliance of the analysis with the requirements of statistical testing.
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Using the lineage determinants Olig2 and Sox10 to explore transcriptional regulation of oligodendrocyte development - Sock, Elisabeth; Wegner, Michael (Developmental Neurobiology, 2021)
The transcription factors Olig2 and Sox10 jointly define oligodendroglial identity. Because of their continuous presence during development and in the differentiated state they shape the oligodendroglial regulatory network at all times. In this review, we exploit their eminent role and omnipresence to elaborate the central principles that organize the gene regulatory network in oligodendrocytes in such a way that it preserves its identity, but at the same time allows defined and stimulus-dependent changes that result in an ordered lineage progression, differentiation, and myelination. For this purpose, we outline the multiple functional and physical interactions and intricate cross-regulatory relationships with other transcription factors, such as Hes5, Id, and SoxD proteins, in oligodendrocyte precursors and Tcf7l2, Sip1, Nkx2.2, Zfp24, and Myrf during differentiation and myelination, and interpret them in the context of the regulatory network.
CRIS-Team Scopus Importer:2021-09-24
Keywords: olig; oligodendrocyte; regulatory network; Sox; transcriptional regulation

UVB radiation represses CYLD expression in melanocytes - Kuphal, Silke; Schneider, Nadja; Massoumi, Ramin; Hellerbrand, Claus; Boßerhoff, Anja Katrin (Oncology Letters, 2017)
CYLD lysine 63 deubiquitinase (CYLD) was originally identified as a tumor suppressor that is mutated in familial cylindromatosis. Unlike in cylindromatosis, downregulation of the deubiquitinase CYLD in melanoma, a highly aggressive tumor, is not caused by mutations in the CYLD gene, but rather by a constitutive and high expression of the snail family transcriptional repressor 1 (SNAIL1). A reduced CYLD level leads to B-cell lymphoma-3/p50/p52-dependent nuclear factor-κB activation, which in turn triggers the expression of genes such as cyclin D1 and N-cadherin. Elevated levels of cyclin D1 and N-cadherin promote melanoma proliferation and invasion. By analyzing the regulation of CYLD expression in melanocytes, the present study identified a signaling pathway that is regulated in response to ultraviolet B (UVB) radiation in melanocytes. UVB light leads to an extracellular signal-regulated kinase-mediated induction of SNAIL1 and subsequent downregulation of CYLD expression in normal human epithelial melanocytes. The UVB-mediated suppression of CYLD in melanocytes may have a key role in the reaction to UV stimuli, and may also potentially be involved in the early malignant transformation processes.
EVALuna2:35803

Validation of the reliability of computational O-GlcNAc prediction - Jochmann, Ramona; Holz, Patrick; Sticht, Heinrich; Stürzl, Michael (Biochimica Et Biophysica Acta-Proteins and Proteomics, 2014)
O-GlcNAcylation is an inducible, highly dynamic and reversible posttranslational modification, which regulates numerous cellular processes such as gene expression, translation, immune reactions, protein degradation, protein-protein interaction, apoptosis, and signal transduction. In contrast to N-linked glycosylation, O-GlcNAcylation does not display a strict amino acid consensus sequence, although serine or threonine residues flanked by proline and valine are preferred sites of O-GlcNAcylation. Based on this information, computational prediction tools of O-GlcNAc sites have been developed. Here, we retrospectively assessed the performance of two available O-GlcNAc prediction programs YinOYang 1.2 server and OGlcNAcScan by comparing their predictions for recently discovered experimentally validated O-GlcNAc sites. Both prediction programs efficiently identified O-GlcNAc sites situated in an environment resembling the consensus sequence P-P-V-[ST]-T-A. However, both prediction programs revealed numerous false negative O-GlcNAc predictions when the site of modification was located in an amino acid sequence differing from the known consensus sequence. By searching for a common sequence motif, we found that O-GlcNAcylation of nucleocytoplasmic proteins preferably occurs at serine and threonine residues flanked downstream by proline and valine and upstream by one to two alanines followed by a stretch of serine and threonine residues. However, O-GlcNAcylation of proteins located in the mitochondria or in the secretory lumen occurs at different sites and does not follow a distinct consensus sequence. Thus, our study indicates the limitations of the presently available computational prediction methods for O-GlcNAc sites and suggests that experimental validation is mandatory. Continuously update and further development of available databases will be the key to improve the performance of O-GlcNAc site prediction.
EVALuna2:15154

Validation Study: Response-Predictive Gene Expression Profiling of Glioma Progenitor Cells In Vitro - Moeckel, Sylvia; Vollmann-Zwerenz, Arabel; Proescholdt, Martin; Brawanski, Alexander; Riemenschneider, Markus J.; Bogdahn, Ulrich; Boßerhoff, Anja Katrin; Spang, Rainer; Hau, Peter (PLoS ONE, 2016)
In a previous publication we introduced a novel approach to identify genes that hold predictive information about treatment outcome. A linear regression model was fitted by using the least angle regression algorithm (LARS) with the expression profiles of a construction set of 18 glioma progenitor cells enhanced for brain tumor initiating cells (BTIC) before and after in vitro treatment with the tyrosine kinase inhibitor Sunitinib. Profiles from treated progenitor cells allowed predicting therapy-induced impairment of proliferation in vitro. Prediction performance was validated in leave one out cross validation.In this study, we used an additional validation set of 18 serum-free short-term treated in vitro cell cultures to test the predictive properties of the signature in an independent cohort. We assessed proliferation rates together with transcriptome-wide expression profiles after Sunitinib treatment of each individual cell culture, following the methods of the previous publication.We confirmed treatment-induced expression changes in our validation set, but our signature failed to predict proliferation inhibition. Neither re-calculation of the combined dataset with all 36 BTIC cultures nor separation of samples into TCGA subclasses did generate a proliferation prediction.Although the gene signature published from our construction set exhibited good prediction accuracy in cross validation, we were not able to validate the signature in an independent validation data set. Reasons could be regression to the mean, the moderate numbers of samples, or too low differences in the response to proliferation inhibition in the validation set. At this stage and based on the presented results, we conclude that the signature does not warrant further developmental steps towards clinical application.
EVALuna2:4729

Variants in ASB10 are associated with open-angle glaucoma - Pasutto, Francesca; Keller, Kate E.; Weisschuh, Nicole; Sticht, Heinrich; Samples, John R.; Yang, Yong-Feng; Zenkel, Matthias; Schlötzer-Schrehardt, Ursula; Mardin, Christian Y.; Frezzotti, Paolo; Edmunds, Beth; Kramer, Patricia L.; et al. (Human Molecular Genetics, 2012)
The molecular events responsible for obstruction of aqueous humor outflow and the loss of retinal ganglion cells in glaucoma, one of the main causes of blindness worldwide, remain poorly understood. We identified a synonymous variant, c.765C>T (Thr255Thr), in ankyrin repeats and suppressor of cytokine signaling box-containing protein 10 (ASB10) in a large family with primary open angle glaucoma (POAG) mapping to the GLC1F locus. This variant affects an exon splice enhancer site and alters mRNA splicing in lymphoblasts of affected family members. Systematic sequence analysis in two POAG patient groups (195 US and 977 German) and their respective controls (85 and 376) lead to the identification of 26 amino acid changes in 70 patients (70 of 1172; 6.0%) compared with 9 in 13 controls (13 of 461; 2.8%; P = 0.008). Molecular modeling suggests that these missense variants change ASB10 net charge or destabilize ankyrin repeats. ASB10 mRNA and protein were found to be strongly expressed in trabecular meshwork, retinal ganglion cells and ciliary body. Silencing of ASB10 transcripts in perfused anterior segment organ culture reduced outflow facility by 50% compared with control-infected anterior segments (P = 0.02). In conclusion, genetic and molecular analyses provide evidence for ASB10 as a glaucoma-causing gene.
EVALuna2:9125

Variants in CPLX1 in two families with autosomal-recessive severe infantile myoclonic epilepsy and ID - Redler, Silke; Strom, Tim M.; Wieland, Thomas; Cremer, Kirsten; Engels, Hartmut; Distelmaier, Felix; Schaper, Jorg; Kuchler, Alma; Lemke, Johannes R.; Jeschke, Stephanie; Schreyer, Nicole; Sticht, Heinrich; et al. (European journal of human genetics, 2017)
For a large number of individuals with intellectual disability (ID), the molecular basis of the disorder is still unknown. However, whole-exome sequencing (WES) is providing more and more insights into the genetic landscape of ID. In the present study, we performed trio-based WES in 311 patients with unsolved ID and additional clinical features, and identified homozygous CPLX1 variants in three patients with ID from two unrelated families. All displayed marked developmental delay and migrating myoclonic epilepsy, and one showed a cerebellar cleft in addition. The encoded protein, complexin 1, is crucially involved in neuronal synaptic regulation, and homozygous Cplx1 knockout mice have the earliest known onset of ataxia seen in a mouse model. Recently, a homozygous truncating variant in CPLX1 was suggested to be causative for migrating epilepsy and structural brain abnormalities. ID was not reported although it cannot be completely ruled out. However, the currently limited knowledge on CPLX1 suggests that loss of complexin 1 function may lead to a complex but variable clinical phenotype, and our findings encourage further investigations of CPLX1 in patients with ID, developmental delay and myoclonic epilepsy to unravel the phenotypic spectrum of carriers of CPLX1 variants.
EVALuna2:33725

Variation of different histone deacetylases and the functional effects of HDAC inhibitors in hepatocellular carcinoma - Freese, Kim; Dietrich, Peter; Boßerhoff, Anja Katrin; Hellerbrand, Claus (JOURNAL OF HEPATOLOGY, 2019)
CRIS-Team WoS Importer:2019-05-07

Viroporins: Structure, function, and their role in the life cycle of SARS-CoV-2 - Breitinger, Ulrike; Farag, Noha S.; Sticht, Heinrich; Breitinger, Hans Georg (International Journal of Biochemistry and Cell Biology, 2022)
Viroporins are indispensable for viral replication. As intracellular ion channels they disturb pH gradients of organelles and allow Ca2+ flux across ER membranes. Viroporins interact with numerous intracellular proteins and pathways and can trigger inflammatory responses. Thus, they are relevant targets in the search for antiviral drugs. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) underlies the world-wide pandemic of COVID-19, where an effective therapy is still lacking despite impressive progress in the development of vaccines and vaccination campaigns. Among the 29 proteins of SARS-CoV-2, the E- and ORF3a proteins have been identified as viroporins that contribute to the massive release of inflammatory cytokines observed in COVID-19. Here, we describe structure and function of viroporins and their role in inflammasome activation and cellular processes during the virus replication cycle. Techniques to study viroporin function are presented, with a focus on cellular and electrophysiological assays. Contributions of SARS-CoV-2 viroporins to the viral life cycle are discussed with respect to their structure, channel function, binding partners, and their role in viral infection and virus replication. Viroporin sequences of new variants of concern (α–ο) of SARS-CoV-2 are briefly reviewed as they harbour changes in E and 3a proteins that may affect their function.
CRIS-Team Scopus Importer:2022-03-11
Keywords: Review; SARSCoV-2; Structure-function relations; Viroporin activity; Viroporin assays; Viroporins

Voluntary wheel running in mice increases the rate of neurogenesis without affecting anxiety-related behaviour in single tests - Garrett, Lillian; Lie, Dieter Chichung; De Angelis, Martin Hrabe; Wurst, Wolfgang; Hoelter, Sabine M. (BMC Neuroscience, 2012)
The role played by adult neurogenesis in anxiety is not clear. A recent study revealed a surprising positive correlation between increased anxiety and elevated neurogenesis following chronic voluntary wheel running and multiple behavioural testing in mice, suggesting that adult hippocampal neurogenesis is involved in the genesis of anxiety. To exclude the possible confounding effect of multiple testing that may have occurred in the aforementioned study, we assessed (1) the effects of mouse voluntary wheel running (14 vs. 28 days) on anxiety in just one behavioural test; the open field, and (2), using different markers, proliferation, differentiation, survival and maturation of newly born neurons in the dentate gyrus immediately afterwards. Effects of wheel running on anxiety-related behaviour were confirmed in a separate batch of animals tested in another test of anxiety, the light/dark box test.Running altered measures of locomotion and exploration, but not anxiety-related behaviour in either test. 14 days running significantly increased proliferation, and differentiation and survival were increased after both running durations. 28 day running mice also exhibited an increased rate of maturation. Furthermore, there was a significant positive correlation between the amount of proliferation, but not maturation, and anxiety measures in the open field of the 28 day running mice.Overall, this evidence suggests that without repeated testing, newly born mature neurons may not be involved in the genesis of anxiety per se.
EVALuna2:4683

Water infusion versus air insufflation for colonoscopy - Hafner, Susanne; Zolk, Karsten; Radaelli, Franco; Otte, Jörg; Rabenstein, Thomas; Zolk, Oliver (Cochrane Database of Systematic Reviews, 2015)
Colonoscopy is a widely used diagnostic and therapeutic modality. A large proportion of the population is likely to undergo colonoscopy for diagnosis and treatment of colorectal diseases, or when participating in colorectal cancer screening programs. To reduce pain, water infusion instead of traditional air insufflation during the insertion phase of the colonoscopy has been proposed, thereby improving patients' acceptance of the procedure. Moreover, the water infusion method may improve early detection of precancerous neoplasms.To compare water infusion techniques with standard air insufflation, specifically evaluating technical quality and screening efficacy, as well as patients' acceptance of the water infusion procedure.We searched the Cochrane Colorectal Cancer Group Specialized Register (February 2014), the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 1), Ovid MEDLINE (1950 to February 2014), Ovid EMBASE (1974 to February 2014), and ClinicalTrials.gov (1999 to February 2014) for eligible randomised controlled trials.We included randomised controlled trials comparing water infusion (water exchange or water immersion methods) against standard air insufflation during the insertion phase of the colonoscopy.Two review authors independently assessed the studies for inclusion and extracted data from eligible studies. We performed analysis using Review Manager software (RevMan 5).We included 16 randomised controlled trials consisting of 2933 colonoscopies. Primary outcome measures were cecal intubation rate and adenoma detection; secondary outcomes were time needed to reach the cecum, pain experienced by participants during the procedure, completion of cecal intubation without sedation/analgesia, and adverse events. Completeness of colonoscopy, that is cecal intubation rate, was similar between water infusion and standard air insufflation (risk ratio 1.00, 95% confidence interval (CI) 0.97 to 1.03, P = 0.93). Adenoma detection rate, that is number of participants with at least one detected adenoma, was slightly improved with water infusion (risk ratio 1.16, 95% CI 1.04 to 1.30, P = 0.007). Assuming the fraction of patients undergoing screening colonoscopy who had one or more adenomas detected was 20 per 100 with standard colonoscopy, the use of water colonoscopy may increase the fraction to 23 per 100 individuals. From our findings, it is possible that up to 68,000 more of the 1.7 million outpatient screening colonoscopies performed annually in the United States, could detect adenomas if water infusion colonoscopy was used. In addition, with water infusion participants experienced significantly less pain (mean difference in pain score on a 0 to 10 scale: -1.57, 95% CI -2.00 to -1.14, P < 0.00001) and a significantly lower proportion of participants requested on-demand sedation or analgesia, or both (risk ratio 1.20, 95% CI 1.14 to 1.27, P < 0.00001). Qualitative analysis suggests that water infusion colonoscopy was not associated with a markedly increased rate of adverse events compared with the standard procedure.Completeness of colonoscopy, that is cecal intubation rate, was not improved by water infusion compared with standard air insufflation colonoscopy. However, adenoma detection, assessed with two different measures (that is adenoma detection rate and number of detected adenomas per procedure), was slightly augmented by the water infusion colonoscopy. Improved adenoma detection might be due to the cleansing effects of water infusions on the mucosa. Detection of premalignant lesions during standard colonoscopy is suboptimal, and so improvements in adenoma detection by water infusion colonoscopy, although small, may help to reduce the risk of interval colorectal carcinoma. The most obvious benefit of water infusion colonoscopy was reduction of procedure-related abdominal pain, which may enhance the acceptance of screening/surveillance colonoscopy.
EVALuna2:8694

Wearable cardioverter defibrillator after cardiac surgery: Analysis of real-life data from patients at transient risk of sudden cardiac death - Elbayomi, Mohamed; Weyand, Michael; Seitz, Tatjana; Harig, Frank (Annals of Noninvasive Electrocardiology, 2023)
Background: Especially in the first 3 months after cardiac surgery, patients are at transient risk of sudden cardiac death (SCD). To close the gap between hospital discharge and the final implantable cardioverter-defibrillator (ICD) decision, guidelines recommend temporarily using a wearable cardioverter-defibrillator (WCD) to protect these patients from SCD. We investigated real-life data on the safety, effectiveness, and compliance of the WCD in this population. Methods: Data for analysis were collected via the Zoll Patient Management Network (ZPM) from patients who underwent cardiac surgery and who were discharged with a WCD between 2018 and 2021 at the Cardiac Surgery Center of the University of Erlangen in Germany. Results: The majority of the 55 patients were male (90.9%) and underwent a coronary artery bypass graft (80.0%). The number of patients with left ventricular ejection fraction (LVEF) >35% increased from 9.1% at the beginning of WCD use to 58.2% at the end of WCD use. Six ventricular tachycardia (VT) episodes occurred in four patients. The WCD appropriately defibrillated two patients with VT episodes. There were no inadequate shocks and no fatalities during the observation time. WCD wearing compliance was high, with a median wear time of 23.3 h/day. Conclusion: This retrospective analysis in a single cardiac surgery center confirms prior data on the safety and effectiveness of the WCD in patients in post-surgery care in a real-life setting. The WCD successfully protected patients from SCD during life-threatening VT episodes. WCD wearing compliance was high.
CRIS-Team Scopus Importer:2023-02-17
Keywords: heart failure; sudden cardiac death; ventricular tachycardia; wearable cardioverter defibrillator

When Mechanical Stress Matters: Generation of Polyploid Giant Cancer Cells in Tumor-Like Microcapsules - Antonelli, Yasmin; Krüger, René; Bühler, Adrian; Monavari, Mahshid; Fuentes Chandia, Miguel Angel; Colombo, Federico; Palmisano, Ralf; Boßerhoff, Anja Katrin; Kappelmann-Fenzl, Melanie; Schödel, Johannes; Boccaccini, Aldo R.; Selhuber-Unkel, Christine; et al. (Advanced Functional Materials, 2024)
Biofabrication techniques enable the performance of bioinspired three-dimensional (3D) matrices resembling primary tumors. To validate their reliability, embedded cells may express complex biophysical responses. Among others, the emergence of tumor heterogeneity and the generation of Polyploid Giant Cancer Cells (PGCC), as a result of the mechanical stress, are two of the most challenging hallmarks to resemble in vitro. Here, these phenomena are studied in cells cultured on two-dimensional (2D) flasks, in 3D spheroids, or immobilized within 3D polymer-based tumor-like microcapsules. These results show that cells cultured in 3D microcapsules exhibited an enhanced biomechanical heterogeneity, a higher number of PGCC, and an increased exertion of cell-matrix attachment forces with respect to the other two experimental conditions. Additionally, cells isolated from tumor-like microcapsules redistribute and align the cytoplasmatic protein Caveolin-1, and upregulate markers involved in cell proliferation (i.e., Ki67), metastasis (i.e., TGF-β1, TGF-β-R2), and epithelial to mesenchymal transition, to name a few. These hallmarks are barely described in the past as a result of the confinement and mechanical stress. Thus, in this work it is demonstrated that both the mechanical stress and confinement are required to stimulate cell polyploidy and biomechanical heterogeneity, which can be easily addressed by immobilizing breast cancer cells in tumor-like microcapsules.
CRIS-Team Scopus Importer:2024-02-16
Keywords: 3D cell culture; cancer biomechanics; intratumor heterogeneity; Polyploid giant cancer cells; Tumor-like microcapsules

Whole-exome sequencing identifies novel causative variants and expands the phenotypic spectrum of PLK4-related primary microcephaly - Boonsawat, Paranchai; Asadollahi, R.; Niedrist, D.; Joset, Pascal; Wisser, J.; Budka, H.; Bode, P. K.; Sticht, Heinrich; Steindl, K.; Rauch, Anita (EUROPEAN JOURNAL OF HUMAN GENETICS, 2019)
CRIS-Team WoS Importer:2021-10-18