Physiological levels of hydrostatic pressure alter morphology and organization of cytoskeletal and adhesion proteins in MG-63 osteosarcoma cells

Biochem Cell Biol. Jan-Feb 1993;71(1-2):27-35. doi: 10.1139/o93-005.

Abstract

The response of human MG-63 osteosarcoma cells to physiological levels of hydrostatic pressure was studied. Cell cultures were subjected to a 20-min, 4-MPa hydrostatic pressure pulse. Adhesion was measured at 20 min and 2 h post-hydrostatic pressure. Morphometric measurements of cell shape and immunofluorescent assays of cytoskeletal and adhesion proteins were done pre- and post-hydrostatic pressure. Pressure-treated cells showed increased adhesion (resistance to deadhesion by trypsinization)-with increased recovery time. Indirect immunofluorescence demonstrated increased heterotypic adhesion receptor at cell-cell interfaces and increased alpha 3, beta 1-integrin at cell-substrate interfaces. Indirect immunofluorescence demonstrated depolymerization of alpha-tubulin, vimentin, and actin during the pressure pulse. Actin reorganization was slower than that of alpha-tubulin and vimentin, with stress filaments not well organized even after 1 h postpressure. The depolymerization of alpha-tubulin, vimentin, and actin observed at relatively low levels of hydrostatic pressure suggests disintegration of the integrin-cytoskeletal attachment complex. The increased resistance of the cells to trypsinization and the increase in both heterotypic adhesion receptor and the alpha 3, beta 1-integrin at cell interfaces suggest that cells compensate for loss of cytoskeletal integrity by increasing attachment to both adjacent cells and the extracellular matrix.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bone and Bones / cytology
  • Bone and Bones / physiology*
  • Cell Adhesion / physiology*
  • Cell Adhesion Molecules
  • Cell Survival
  • Cytoskeletal Proteins / isolation & purification
  • Cytoskeleton / physiology*
  • Fluorescent Antibody Technique
  • Humans
  • Hydrostatic Pressure
  • Integrins / isolation & purification
  • Morphogenesis / physiology*
  • Osteosarcoma
  • Time Factors
  • Tumor Cells, Cultured

Substances

  • Cell Adhesion Molecules
  • Cytoskeletal Proteins
  • Integrins