Haskin C, Cameron I, Athanasiou K
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, 78284-7762.
Biochem Cell Biol. 1993 Jan-Feb;71(1-2):27-35. doi: 10.1139/o93-005.
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.
研究了人MG - 63骨肉瘤细胞对生理水平静水压力的反应。细胞培养物接受了20分钟、4兆帕的静水压力脉冲处理。在静水压力处理后20分钟和2小时测量细胞黏附情况。在静水压力处理前后对细胞形状进行形态测量，并对细胞骨架和黏附蛋白进行免疫荧光测定。压力处理后的细胞显示出黏附增加（对胰蛋白酶消化导致的脱黏附的抵抗力），且恢复时间增加。间接免疫荧光显示细胞 - 细胞界面处异型黏附受体增加，细胞 - 底物界面处α3β1整合素增加。间接免疫荧光显示在压力脉冲期间α - 微管蛋白、波形蛋白和肌动蛋白发生解聚。肌动蛋白的重组比α - 微管蛋白和波形蛋白慢，即使在压力处理后1小时应激丝仍未很好地组织起来。在相对较低水平的静水压力下观察到的α - 微管蛋白、波形蛋白和肌动蛋白的解聚表明整合素 - 细胞骨架附着复合体解体。细胞对胰蛋白酶消化的抵抗力增加以及细胞界面处异型黏附受体和α3β1整合素的增加表明，细胞通过增加与相邻细胞和细胞外基质的附着来补偿细胞骨架完整性的丧失。
