Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan; Innovation Laboratory, Tokyo Institute of Technology, Yokohama, Japan.
Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan; Innovation Laboratory, Tokyo Institute of Technology, Yokohama, Japan.
Biophys J. 2011 Feb 2;100(3):564-572. doi: 10.1016/j.bpj.2010.12.3693.
The cellular response to external mechanical forces has important effects on numerous biological phenomena. The sequences of molecular events that underlie the observed changes in cellular properties have yet to be elucidated in detail. Here we have detected the responses of a cultured cell against locally applied cyclic stretching and compressive forces, after creating an artificial focal adhesion under a glass bead attached to the cantilever of an atomic force microscope. The cell tension initially increased in response to the tensile stress and then decreased within ∼1 min as a result of viscoelastic properties of the cell. This relaxation was followed by a gradual increase in tension extending over several minutes. The slow recovery of tension ceased after several cycles of force application. This tension-recovering activity was inhibited when cells were treated with cytochalasin D, an inhibitor of actin polymerization, or with (-)-blebbistatin, an inhibitor of myosin II ATPase activity, suggesting that the activity was driven by actin-myosin interaction. To our knowledge, this is the first quantitative analysis of cellular mechanical properties during the process of adaptation to locally applied cyclic external force.
细胞对外界机械力的反应对许多生物现象有重要影响。然而，在观察到的细胞特性变化背后的分子事件序列尚未被详细阐明。在这里，我们在原子力显微镜的悬臂上附着玻璃珠，在其表面创建一个人工黏附点，检测了培养细胞对此处施加的局部周期性拉伸和压缩力的反应。细胞张力最初会随拉伸应力而增加，然后由于细胞的黏弹性，在大约 1 分钟内下降。这种弛豫之后，张力会在几分钟内逐渐增加。在经过几次力的施加循环后，张力的缓慢恢复停止。当用细胞松弛素 D（一种肌动蛋白聚合抑制剂）或 (-)-blebbistatin（一种肌球蛋白 II ATP 酶活性抑制剂）处理细胞时，这种张力恢复活性会被抑制，这表明该活性是由肌动蛋白-肌球蛋白相互作用驱动的。据我们所知，这是首次对细胞适应局部施加周期性外力过程中的细胞力学特性进行定量分析。
