Strain reorganizes focal adhesions and cytoskeleton in cultured airway smooth muscle cells.
Strain reorganizes focal adhesions and cytoskeleton in cultured airway smooth muscle cells.
复制标题
DOI：
10.1006/excr.1997.3492
复制
发表时间：
1997-04
影响因子：
3.7
通讯作者：
Paul G. Smith;Rosa Garcia;Lembi Kogerman
中科院分区：
文献类型：
--
作者：
Paul G. Smith;Rosa Garcia;Lembi Kogerman
肺结构上的异常机械应力与气道阻力增加和由于气道平滑肌(ASM)沉积增加而导致的气体交换障碍有关。使用体外培养的ASM细胞系统，我们已经证明了循环变形应变增加了ASM细胞的肌球蛋白和肌球蛋白轻链激酶。为了确定这些收缩蛋白的增加是否伴随着细胞的超微结构变化，表明表型变化，通过透射电子显微镜和荧光染色比较了承受应变的细胞和在静态条件下生长的细胞。与物理静态条件下生长的相同细胞相比，垂直于应变方向的应变ASM细胞更细长，含有更多的肌动蛋白应力纤维。应力纤维束较粗，沿细胞长轴方向排列。通过透射电子显微镜和Talin免疫组织化学染色，发现细胞膜和基质之间的灶性粘连的数目和长度明显增加。因此，机械应变增加了培养的ASM细胞中细胞骨架元素的组织。体内类似的作用可能有助于促进培养的ASM细胞的收缩表型的表达，而不依赖于体内的其他因素，并改变细胞的收缩能力。增加细胞骨架元素的组织也可能提高从细胞外基质到细胞内部的信号转导效率。
Abnormal mechanical stress on pulmonary structures is associated with increased airway resistance and impaired gas exchange as a result of increased airway smooth muscle (ASM) deposition. Using an in vitro system with cultured ASM cells, we have demonstrated that cyclic deformational strain increases ASM cellular myosin and myosin light chain kinase. To determine if these contractile protein increases were accompanied by ultrastructural changes in cells indicating phenotypic modulation, cells subjected to strain were compared to cells grown under static conditions by transmission electron microscopy (TEM) and fluorescent staining. The strained ASM cells oriented perpendicular to the strain direction were more elongated and contained more actin stress fibers than identical cells grown under physically static conditions. The stress fiber bundles were thicker and reorganized parallel to the long axis of the cell. Marked increases in the numbers and lengths of focal adhesions between the cell membrane and the substratum were found by both TEM and immunostaining for talin. Mechanical strain thus increases organization of cytoskeletal elements in cultured ASM cells. Similar effects in vivo may serve to promote the expression of the contractile phenotype of cultured ASM cells independent of other in vivo factors and alter cell contractility. Increased organization of cytoskeletal elements might also increase the efficiency of signal transduction from the extracellular matrix into the cell interior.