title: Time course of actin cytoskeleton stiffness and matrix adhesion molecules in human bronchial epithelial cell cultures.
abstract: Human bronchial epithelial (HBE) cells adhere to underlying extracellular matrix (ECM) via integrin-type transmembrane receptors. Integrins link the ECM to the cytoskeleton (CSK), establishing a mechanical continuum by which forces are transmitted between the outside and the inside of the cells. The present study investigates the time course of global and actin CSK stiffness of HBE cells (16HBE14o-) growing on various matrix substrates as a function of culture time until confluence, and the concomitant time course of F-actin and adhesion molecule distribution. Our results showed a progressive increase in actin CSK stiffness from cell seeding to confluence, related to acquisition of highly polymerized cortical and cytosolic F-actin organization and up-regulation of certain matrix ligands, such as beta 1-, alpha 5-, and alpha v-integrin subunit expression. Moreover, compared to fibrillar type I collagen, reticular type IV collagen used as matrix substrate, appeared to amplify actin CSK stiffness of HBE confluent cells probably in relation to up-regulation of alpha 3-integrin subunit. Taken together, these results support the concept of a close interaction among actin CSK stiffness, structural actin organization, specific integrin molecule involvement, cell spreading, and extracellular matrix.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, INSERM U492 de Physiopathologie et Thérapeutique Respiratoires, Faculté de Médecine, 94010 Créteil, France.
authors.forename: Blandine
authors.initials: B
authors.lastname: Doornaert
authors.forename: Valérie
authors.initials: V
authors.lastname: Leblond
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Planus
authors.forename: Stéphane
authors.initials: S
authors.lastname: Galiacy
authors.forename: Valérie M
authors.initials: VM
authors.lastname: Laurent
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gras
authors.forename: Daniel
authors.initials: D
authors.lastname: Isabey
authors.forename: Chantal
authors.initials: C
authors.lastname: Lafuma
mesh_terms: D000199:Actins / Q000378:metabolism*; D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D015820:Cadherins / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002455:Cell Division; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D013997:Time Factors
chemical_list: D000199:Actins; D015820:Cadherins; D015815:Cell Adhesion Molecules