Badley R A, Woods A, Carruthers L, Rees D A
J Cell Sci. 1980 Jun;43:379-90. doi: 10.1242/jcs.43.1.379.
The organization of the cytoskeleton in several anchorage-dependent fibroblast types has been compared with the pattern of adhesions to a glass substratum which will support either their growth or just their spreading. Components were stained separately for immunofluorescence microscopy using specific antisera against actin, tubulin, and gizzard 10-nm filament protein, and the adhesions were visualized by interference-reflexion microscopy. Of the cytoskeleton features, only stress fibres could be related to the pattern of focal adhesions; as shown before, each focal adhesion lies directly beneath a stress fibre, often near the terminus. Cells spread on fibronectin-treated glass in serum-free medium to arrest the development of focal adhesions, show correspondingly underdeveloped stress fibres. Actin geodesic domes, microtubules, and 10-nm filaments showed no relations with the adhesion pattern. During cell rounding leading to detachment with either EGTA or trypsin, stress fibres begin to disperse in advance of shape change whereas microtubules and 10-nm filaments seem to alter their distribution as a consequence of shape change. We therefore confirm that stress fibres are the cytoskeleton features most directly related to focal adhesions and are cytoskeleton targets for 2 agents which cause rounding and hence detachment. The sequences of events in dispersal of stress fibres by EGTA and by trypsin showed significant differences in detail. With trypsin, fibres higher in the cell and terminating at the cell edge were more sensitive than most basal fibres and, during disintegration, all types of fibre went through an intermediate 'beaded' structure. With EGTA, all stress fibres seemed to be similarly susceptible and the beaded stage was not seen. The implications of these differences for our understanding of the mechanisms of dispersal of stress fibres are discussed.
已将几种贴壁依赖型成纤维细胞类型的细胞骨架组织与它们在玻璃基质上的黏附模式进行了比较，该玻璃基质既能支持细胞生长，也能仅支持细胞铺展。使用针对肌动蛋白、微管蛋白和胃蛋白酶10纳米丝蛋白的特异性抗血清，分别对细胞成分进行免疫荧光显微镜染色，并通过干涉反射显微镜观察黏附情况。在细胞骨架特征中，只有应力纤维与粘着斑模式相关；如前所示，每个粘着斑都直接位于一条应力纤维下方，通常靠近其末端。在无血清培养基中铺展在纤连蛋白处理过的玻璃上以阻止粘着斑发育的细胞，相应地显示出不发达的应力纤维。肌动蛋白 geodesic 穹顶、微管和10纳米丝与黏附模式无关。在用乙二醇双乙胺四乙酸（EGTA）或胰蛋白酶处理导致细胞变圆并脱离的过程中，应力纤维在形状改变之前就开始分散，而微管和10纳米丝似乎是由于形状改变而改变其分布。因此，我们证实应力纤维是与粘着斑最直接相关的细胞骨架特征，并且是导致细胞变圆从而脱离的两种试剂作用的细胞骨架靶点。EGTA和胰蛋白酶使应力纤维分散的事件顺序在细节上有显著差异。用胰蛋白酶处理时，细胞中较高且终止于细胞边缘的纤维比较大多数基部纤维更敏感，并且在解体过程中，所有类型的纤维都会经历一个中间的“串珠状”结构。用EGTA处理时，所有应力纤维似乎同样敏感，并且未观察到串珠阶段。讨论了这些差异对我们理解应力纤维分散机制的意义。
