Contribution of intermediate filaments to cell stiffness, stiffening, and growth.
Contribution of intermediate filaments to cell stiffness, stiffening, and growth.
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DOI：
10.1152/ajpcell.2000.279.1.c188
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发表时间：
2000-07
期刊：
影响因子：
--
通讯作者：
Ning Wang;D. Stamenović
中科院分区：
文献类型：
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作者：
Ning Wang;D. Stamenović
先前已经表明，中间丝（IF）凝胶在体外在高施加应力下表现出硬化，并且表明IF的这种硬化性质对于在大变形下保持细胞完整性可能是重要的（Janmey PA，Evtenever V，Traub P，and Schliwa M，J Cell Biol 113：155 - 160，1991）。在这项研究中，IFs的细胞力学行为的贡献进行了研究，通过测量细胞刚度在施加应力在贴壁野生型和波形蛋白缺陷的成纤维细胞，使用磁扭转细胞术。结果发现，波形蛋白缺陷细胞的硬度较低，表现出比野生型细胞更少的硬度，除了在最低的施加应力（10达因/厘米（2）），在刚度的差异不显着。在波形蛋白IF被丙烯酰胺破坏后，从野生型成纤维细胞和内皮细胞的测量中获得了类似的结果。然而，如果细胞在延长的时间段（16小时）内铺板，即使在最低的施加应力下，它们也表现出比丙烯酰胺之前更大的刚度。一个可能的原因可能是，最初松弛的IF由于高度的细胞铺展而完全伸展，从而有助于机械应力在细胞上的传递。两者合计，这些发现是一致的概念，即IFs发挥重要作用的力学性能的细胞在大变形。实验数据还表明，耗尽或破坏IF减少，但没有完全消除，细胞硬化。这种残余硬化可能是由于细胞骨架丝在施加载荷的方向上的几何重新排列的影响。还发现波形蛋白缺陷细胞表现出比野生型细胞更慢的增殖和DNA合成速率。这可能是缺乏细胞内IF的直接结果，而这些IF可能是细胞内机械信号有效介导所必需的。总之，本研究的结果表明，IFs在细胞的机械性能和细胞生长中发挥重要作用。
It has been shown previously that intermediate filament (IF) gels in vitro exhibit stiffening at high-applied stress, and it was suggested that this stiffening property of IFs might be important for maintaining cell integrity at large deformations (Janmey PA, Evtenever V, Traub P, and Schliwa M, J Cell Biol 113: 155-160, 1991). In this study, the contribution of IFs to cell mechanical behavior was investigated by measuring cell stiffness in response to applied stress in adherent wild-type and vimentin-deficient fibroblasts using magnetic twisting cytometry. It was found that vimentin-deficient cells were less stiff and exhibited less stiffening than wild-type cells, except at the lowest applied stress (10 dyn/cm(2)) where the difference in the stiffness was not significant. Similar results were obtained from measurements on wild-type fibroblasts and endothelial cells after vimentin IFs were disrupted by acrylamide. If, however, cells were plated over an extended period of time (16 h), they exhibited a significantly greater stiffness before than after acrylamide, even at the lowest applied stress. A possible reason could be that the initially slack IFs became fully extended due to a high degree of cell spreading and thus contributed to the transmission of mechanical stress across the cell. Taken together, these findings were consistent with the notion that IFs play important roles in the mechanical properties of the cell during large deformation. The experimental data also showed that depleting or disrupting IFs reduced, but did not entirely abolish, cell stiffening. This residual stiffening might be attributed to the effect of geometrical realignment of cytoskeletal filaments in the direction of applied load. It was also found that vimentin-deficient cells exhibited a slower rate of proliferation and DNA synthesis than wild-type cells. This could be a direct consequence of the absence of the intracellular IFs that may be necessary for efficient mediation of mechanical signals within the cell. Taken together, results of this study suggest that IFs play important roles in the mechanical properties of cells and in cell growth.