title: Critical centrifugal forces induce adhesion rupture or structural reorganization in cultured cells.
abstract: Cultured epithelial cells were exposed to accelerations ranging from 9,000 to 70,000g for time periods of 5, 15, or 60 min, by centrifugation in a direction tangential to their plastic substrate. Three regimes describe the cellular response: (1) Cell morphology and density remain unaltered at forces below a threshold of about 10(-7) N; (2) Between this critical force and a second threshold of about 1.5 10(-7)N, the number of adherent cells decreases exponentially with time and acceleration, with no alteration of cell morphology. This behavior can be modeled by a constant probability of detaching and by an exponential distribution of cell-to-substrate adhesive forces; (3) Past the second threshold, cells that are still adherent exhibit elongated morphologies, the degree of elongation increasing linearly with the force. The fact that cells lose their vinculin-rich focal contacts past the first threshold and that cells cultured on gelatin-coated plastic show an increased resistance to detachment suggests a rupture of cell-to-substrate adhesions upon centrifugation. Immunofluorescent labeling of cells for actin and tubulin shows a reorganization of the cytoskeleton upon centrifugation, and treatment of cells with the drugs cytochalasin D and nocodazole demonstrates that cytoskeletal elements are actively involved in the structural deformation of cells past the second acceleration threshold, microtubules and microfilaments paying antagonistic roles.
authors.affiliation: Section de Recherche, Institut Curie, Paris, France.
authors.forename: O
authors.initials: O
authors.lastname: Thoumine
authors.forename: A
authors.initials: A
authors.lastname: Ott
authors.forename: D
authors.initials: D
authors.lastname: Louvard
mesh_terms: D001940:Breast / Q000166:cytology* / Q000378:metabolism; D002448:Cell Adhesion; D002452:Cell Count; D002478:Cells, Cultured; D002498:Centrifugation; D003599:Cytoskeleton; D004847:Epithelial Cells; D005260:Female; D006112:Gravitation; D006801:Humans; D008863:Microspheres; D013997:Time Factors