title: Collagen VI is a basement membrane component that regulates epithelial cell-fibronectin interactions.
abstract: Collagen VI is a heterotrimer composed of three α chains (α1, α2, α3) widely expressed throughout various interstitial matrices. Collagen VI is also found near the basement membranes of many tissues where it serves as an anchoring meshwork. The aim of this study was to investigate the distribution and role of collagen VI at the epithelial-stromal interface in the intestine. Results showed that collagen VI is a bona fide epithelial basal lamina component and constitutes the major collagen type of epithelial origin in this organ. In vitro, collagen VI co-distributes with fibronectin. Targeted knockdown of collagen VI expression in intestinal epithelial cells was used to investigate its function. Depletion of collagen VI from the matrix led to a significant increase in cell spreading and fibrillar adhesion formation coinciding with an upregulation of fibronectin expression, deposition and organization as well as activation of myosin light chain phosphorylation by the myosin light chain kinase and Rho kinase dependent mechanisms. Plating cells deficient for collagen VI on collagen VI rescued the phenotype. Taken together, these data demonstrate that collagen VI is an important basal lamina component involved in the regulation of epithelial cell behavior most notably as a regulator of epithelial cell-fibronectin interactions.
authors.affiliation: CIHR Team on the Digestive Epithelium, Department of Anatomy and Cell Biology, Université de Sherbrooke, Québec, Canada.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Groulx
authors.forename: David
authors.initials: D
authors.lastname: Gagné
authors.forename: Yannick D
authors.initials: YD
authors.lastname: Benoit
authors.forename: Denis
authors.initials: D
authors.lastname: Martel
authors.forename: Nuria
authors.initials: N
authors.lastname: Basora
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Beaulieu
mesh_terms: D001485:Basement Membrane / Q000378:metabolism*; D002465:Cell Movement; D048430:Cell Shape / Q000235:genetics; D002478:Cells, Cultured; D024142:Collagen Type VI / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D022001:Focal Adhesions / Q000378:metabolism; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism; D008840:Microfilament Proteins / Q000378:metabolism; D018994:Myosin Light Chains / Q000378:metabolism; D009219:Myosin-Light-Chain Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation; D034622:RNA Interference; D000070876:Tensins; D014158:Transcription, Genetic
chemical_list: D024142:Collagen Type VI; D005353:Fibronectins; D019012:Integrin beta1; D008840:Microfilament Proteins; D018994:Myosin Light Chains; D000070876:Tensins; D009219:Myosin-Light-Chain Kinase