Spatiotemporal analysis of flow-induced intermediate filament displacement in living endothelial cells
Spatiotemporal analysis of flow-induced intermediate filament displacement in living endothelial cells
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DOI：
10.1016/s0006-3495(01)76006-7
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发表时间：
2001-01-01
影响因子：
3.4
通讯作者：
Davies, PF
中科院分区：
文献类型：
--
作者：
Helmke, BP;Thakker, DB;Davies, PF
整个动脉树的血流动力学剪切应力的分布由内皮细胞转变成调节血管活性、血管壁重塑和动脉粥样硬化形成的局部细胞反应。尽管机械转导的确切机制仍然未知，但内皮细胞骨架通过与管腔、细胞间和基底表面的连接将细胞外力传递到信号产生的细胞质位点。对表达绿色荧光蛋白波形蛋白的细胞中中间丝 (IF) 位移的直接观察表明，细胞骨架力学因流体剪切应力的出现而迅速改变。在这里，将延时光学切片荧光显微镜恢复的图像分析为代表 IF 位置的四维强度分布函数。与乘积矩相关系数相关的位移指数作为时间和亚细胞空间位置的函数，证明了汇合单层内皮细胞内 IF 位移的模式，与盖玻片表面附近测量的相比，流动开始导致细胞核上方 IF 位移显着增加，并且细胞核下游的位移大于上游区域。此外，相邻细胞边缘附近 IF 的协调位移表明细胞之间存在机械连续性。因此，对流动引起的 IF 位移的时空模式的定量分析表明，响应作用于管腔表面的血流动力学剪切应力的变化，细胞内力重新分布。
The distribution of hemodynamic shear stress throughout the arterial tree is transduced by the endothelium into local cellular responses that regulate vasoactivity, vessel wall remodeling, and atherogenesis, Although the exact mechanisms of mechanotransduction remain unknown, the endothelial cytoskeleton has been implicated in transmitting extracellular force to cytoplasmic sites of signal generation via connections to the lumenal, intercellular, and basal surfaces. Direct observation of intermediate filament (IF) displacement in cells expressing green fluorescent protein-vimentin has suggested that cytoskeletal mechanics are rapidly altered by the onset of fluid shear stress. Here, restored images from time-lapse optical sectioning fluorescence microscopy were analyzed as a four-dimensional intensity distribution function that represented IF positions. A displacement index, related to the product moment correlation coefficient as a function of time and subcellular spatial location, demonstrated patterns of IF displacement within endothelial cells in a confluent monolayer, Flow onset induced a significant increase in IF displacement above the nucleus compared with that measured near the coverslip surface, and displacement downstream from the nucleus was larger than in upstream areas. Furthermore, coordinated displacement of IF near the edges of adjacent cells suggested the existence of mechanical continuity between cells. Thus, quantitative analysis of the spatiotemporal patterns of flow-induced IF displacement suggests redistribution of intracellular force in response to alterations in hemodynamic shear stress acting at the lumenal surface.