title: Cell confinement controls centrosome positioning and lumen initiation during epithelial morphogenesis.
abstract: Epithelial organ morphogenesis involves sequential acquisition of apicobasal polarity by epithelial cells and development of a functional lumen. In vivo, cells perceive signals from components of the extracellular matrix (ECM), such as laminin and collagens, as well as sense physical conditions, such as matrix stiffness and cell confinement. Alteration of the mechanical properties of the ECM has been shown to promote cell migration and invasion in cancer cells, but the effects on epithelial morphogenesis have not been characterized. We analyzed the effects of cell confinement on lumen morphogenesis using a novel, micropatterned, three-dimensional (3D) Madin-Darby canine kidney cell culture method. We show that cell confinement, by controlling cell spreading, limits peripheral actin contractility and promotes centrosome positioning and lumen initiation after the first cell division. In addition, peripheral actin contractility is mediated by master kinase Par-4/LKB1 via the RhoA-Rho kinase-myosin II pathway, and inhibition of this pathway restores lumen initiation in minimally confined cells. We conclude that cell confinement controls nuclear-centrosomal orientation and lumen initiation during 3D epithelial morphogenesis.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Alejo E
authors.initials: AE
authors.lastname: Rodríguez-Fraticelli
authors.forename: Muriel
authors.initials: M
authors.lastname: Auzan
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Alonso
authors.forename: Michel
authors.initials: M
authors.lastname: Bornens
authors.forename: Fernando
authors.initials: F
authors.lastname: Martín-Belmonte
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D002478:Cells, Cultured; D018385:Centrosome / Q000378:metabolism / Q000502:physiology*; D003094:Collagen / Q000378:metabolism; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology* / Q000502:physiology*; D005109:Extracellular Matrix / Q000378:metabolism / Q000502:physiology; D007797:Laminin / Q000378:metabolism*; D009024:Morphogenesis / Q000502:physiology*; D024462:Myosin Type II / Q000037:antagonists & inhibitors / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000503:physiopathology; D054460:rho-Associated Kinases / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D000199:Actins; D007797:Laminin; D003094:Collagen; D054460:rho-Associated Kinases; D024462:Myosin Type II; D020742:rhoA GTP-Binding Protein