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

作者：Luz del Carmen Martínez-Sánchez, Phuong Anh Ngo, Rashmita Pradhan, Lukas S. Becker, David Boehringer, Despina Soteriou, Markéta Kubánková, Christine Schweitzer, Tatyana Koch, Veronika Thonn, Lena Erkert, Iris Stolzer, Claudia Günther, Christoph Becker, Benno Weigmann, Monika Klewer, Christoph Daniel, Kerstin Amann, Stefan Tenzer, Raja Narayana Atreya, Martin O. Bergö, Cord Herbert Brakebusch, Alastair J.M. Watson, Jochen R. Guck, Ben Fabry, Imke Atreya, Markus Friedrich Neurath, Rocío López-Posadas · 发表于：Gut · 年份：2022 · DOI：10.1136/gutjnl-2021-325520 · 被引用次数：75 · 研究领域：Barrier Structure and Function Studies、Cellular Mechanics and Interactions、Cell Adhesion Molecules Research

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: 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: 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 functi...