Yu J T, López Bernal A
Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, UK.
J Reprod Fertil. 1998 Jan;112(1):185-98. doi: 10.1530/jrf.0.1120185.
Eukaryotic cells have an internal cytoskeletal scaffolding, giving them their distinctive shapes. The cytoskeleton enables cells to transport vesicles, undergo changes in shape, migrate and contract. This dynamic structure is formed by three classes of filamentous assembly: actin microfilaments, intermediate filaments and microtubules. In this investigation the cytoskeleton of cultured human myometrial cells was studied by immunohistochemistry using specific antibodies against vinculin, cytokeratin, vimentin, tubulin and RhoA, covalently labelled with a fluorescent tag. Polymerized actin was visualized with fluorescein-conjugated phalloidin. Myometrial cells were very rich in actin fibres, which generally appeared as parallel bundles along the longest axis of the cells. There was a strong expression of vinculin which concentrated at actin--vinculin focal adhesion sites. By contrast, intermediate filaments (vimentin and cytokeratin) were organized in a dense cytoplasmic meshwork which excluded the nuclear space. A similar pattern was observed for tubulin. RhoA had a diffuse distribution and was associated with actin fibres. Exposure of the cells to oxytocin provoked a 10% shortening of actin stress fibres. These results demonstrate that myometrial smooth muscle cells have a rich cytoskeletal structure and that agonists that stimulate myometrial activation provoke measurable changes in actin fibres which may be important for efficient contractility.
真核细胞具有内部细胞骨架支架，赋予它们独特的形状。细胞骨架使细胞能够运输囊泡、改变形状、迁移和收缩。这种动态结构由三类丝状组件形成：肌动蛋白微丝、中间丝和微管。在本研究中，使用针对纽蛋白、细胞角蛋白、波形蛋白、微管蛋白和RhoA的特异性抗体，通过免疫组织化学研究培养的人子宫肌层细胞的细胞骨架，这些抗体用荧光标签共价标记。用荧光素偶联的鬼笔环肽观察聚合的肌动蛋白。子宫肌层细胞富含肌动蛋白纤维，这些纤维通常沿细胞最长轴呈平行束状出现。纽蛋白有强烈表达，集中在肌动蛋白 - 纽蛋白粘着斑部位。相比之下，中间丝（波形蛋白和细胞角蛋白）在致密的细胞质网络中排列，排除了核空间。微管蛋白也观察到类似模式。RhoA分布弥散，与肌动蛋白纤维相关。用催产素处理细胞会导致肌动蛋白应力纤维缩短10%。这些结果表明，子宫肌层平滑肌细胞具有丰富的细胞骨架结构，刺激子宫肌层活化的激动剂会引起肌动蛋白纤维的可测量变化，这可能对有效的收缩性很重要。
