Epithelial RAC1-dependent cytoskeleton dynamics controls cell mechanics, cell shedding and barrier integrity in intestinal inflammation

Martínez Sánchez LdC, Phuong Anh Ngo , Pradhan R, Becker LS, Böhringer D, Soteriou D, Kubankova M, Schweitzer C, Koch T, Thonn V, Erkert L, Stolzer I, Günther C, Becker C, Weigmann B, Klewer M, Daniel C, Amann KU, Tenzer S, Atreya R, Bergo M, Brakebusch C, Watson AJM, Guck J, Fabry B, Atreya I, Neurath M, Lopez Posadas R (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Gut BMJ Publishing Group

DOI: 10.1136/gutjnl-2021-325520

Abstract

Objective Increased apoptotic shedding has been linked to intestinal barrier dysfunction and development of inflammatory bowel diseases (IBD). In contrast, physiological cell shedding allows the renewal of the epithelial monolayer without compromising the barrier function. Here, we investigated the role of live cell extrusion in epithelial barrier alterations in IBD. Design Taking advantage of conditional GGTase and RAC1 knockout mice in intestinal epithelial cells (Pggt1b (i Delta IEC) and Rac1 (i Delta IEC) mice), intravital microscopy, immunostaining, mechanobiology, organoid techniques and RNA sequencing, we analysed cell shedding alterations within the intestinal epithelium. Moreover, we examined human gut tissue and intestinal organoids from patients with IBD for cell shedding alterations and RAC1 function. Results Epithelial Pggt1b deletion led to cytoskeleton rearrangement and tight junction redistribution, causing cell overcrowding due to arresting of cell shedding that finally resulted in epithelial leakage and spontaneous mucosal inflammation in the small and to a lesser extent in the large intestine. Both in vivo and in vitro studies (knockout mice, organoids) identified RAC1 as a GGTase target critically involved in prenylation-dependent cytoskeleton dynamics, cell mechanics and epithelial cell shedding. Moreover, inflamed areas of gut tissue from patients with IBD exhibited funnel-like structures, signs of arrested cell shedding and impaired RAC1 function. RAC1 inhibition in human intestinal organoids caused actin alterations compatible with arresting of cell shedding. Conclusion Impaired epithelial RAC1 function causes cell overcrowding and epithelial leakage thus inducing chronic intestinal inflammation. Epithelial RAC1 emerges as key regulator of cytoskeletal dynamics, cell mechanics and intestinal cell shedding. Modulation of RAC1 might be exploited for restoration of epithelial integrity in the gut of patients with IBD.

Authors with CRIS profile

Luz del Carmen Martínez Sánchez Lehrstuhl für Innere Medizin I David Böhringer Lehrstuhl für Biophysik Lena Erkert Department of Medicine 1 – Gastroenterology, Pneumology and Endocrinology Iris Stolzer Department of Medicine 1 – Gastroenterology, Pneumology and Endocrinology Claudia Günther Department of Medicine 1 – Gastroenterology, Pneumology and Endocrinology Christoph Becker Professur für Molekulare Gastroenterologie Benno Weigmann Medizinische Fakultät Christoph Daniel Department of Nephropathology Kerstin Ute Amann Professur für Nephropathologie Raja Atreya Professur für Translationale Immunforschung bei chronisch entzündlichen Darmerkrankungen (Heisenberg-Professur) Jochen Guck Lehrstuhl für Biologische Optomechanik Ben Fabry Lehrstuhl für Biophysik Imke Atreya Department of Medicine 1 – Gastroenterology, Pneumology and Endocrinology Markus Neurath Lehrstuhl für Innere Medizin I Rocío Lopez Posadas Department of Medicine 1 – Gastroenterology, Pneumology and Endocrinology

Involved external institutions

University of Copenhagen DK Denmark (DK) Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE) University of East Anglia GB United Kingdom (GB) Karolinska Institute SE Sweden (SE) Johannes Gutenberg-Universität Mainz (JGU) DE Germany (DE)

How to cite

APA:

Martínez Sánchez, L.d.C., Phuong Anh Ngo, ., Pradhan, R., Becker, L.S., Böhringer, D., Soteriou, D.,... Lopez Posadas, R. (2022). Epithelial RAC1-dependent cytoskeleton dynamics controls cell mechanics, cell shedding and barrier integrity in intestinal inflammation. Gut. https://doi.org/10.1136/gutjnl-2021-325520

MLA:

Martínez Sánchez, Luz del Carmen, et al. "Epithelial RAC1-dependent cytoskeleton dynamics controls cell mechanics, cell shedding and barrier integrity in intestinal inflammation." Gut (2022).

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