Direct measurement of shear strain in adherent vascular endothelial cells exposed to fluid shear stress
Direct measurement of shear strain in adherent vascular endothelial cells exposed to fluid shear stress
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DOI：
10.1016/j.bbrc.2010.02.115
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发表时间：
2010-03-26
影响因子：
3.1
通讯作者：
Sato, Masaaki
中科院分区：
文献类型：
--
作者：
Ueki, Yosuke;Sakamoto, Naoya;Sato, Masaaki
内皮细胞（EC）对流体剪切应力的功能和形态反应被认为是由几种机械敏感分子介导的。然而，由于流体剪切应力施加到内皮细胞的顶端表面的力是如何传递到机械传感器知之甚少。本文采用一种新颖的实验方法，通过观察活体内皮细胞在剪应力作用下的变形行为，对细胞内力学场进行了分析。通过共聚焦显微镜获得人脐静脉内皮细胞流动开始前后的侧向图像，并进行图像相关和有限元分析，以定量分析由于剪切应力引起的亚细胞应变。随着剪切应力的大小从2 Pa增加到10 Pa，细胞的剪切应变从1.06 +/- 1.09%（平均值+/- SD）变为4.67 +/- 1.79%。内皮细胞的细胞核也表现出剪切变形，这是类似于在细胞质中观察到的，这表明细胞核传递力从顶端到细胞内的组件，以及细胞骨架。所获得的应变-应力关系导致粘附EC的平均剪切模量为213 Pa。这些结果提供了一个机械的角度对EC的流量传感机制的调查。(C)2010年爱思唯尔公司All rights reserved.
Functional and morphological responses of endothelial cells (ECs) to fluid shear stress are thought to be mediated by several mechanosensitive molecules. However, how the force due to fluid shear stress applied to the apical surface of ECs is transmitted to the mechanosensors is poorly understood. In the present paper, we performed an analysis of an intracellular mechanical field by observation of the deformation behaviors of living ECs exposed to shear stress with a novel experimental method. Lateral images of human umbilical vein ECs before and after the onset of flow were obtained by confocal microscopy, and image correlation and finite element analysis were performed for quantitative analyses of subcellular strain due to shear stress. The shear strain of the cells changed from 1.06 +/- 1.09% (mean +/- SD) to 4.67 +/- 1.79% as the magnitude of the shear stress increased from 2 to 10 Pa. The nuclei of ECs also exhibited shear deformation, which was similar to that observed in cytoplasm, suggesting that nuclei transmit forces from apical to intracellular components, as well as cytoskeletons. The obtained strain-stress relation resulted in a mean shear modulus of 213 Pa for adherent ECs. These results provide a mechanical perspective on the investigation of flow-sensing mechanisms of ECs. (C) 2010 Elsevier Inc. All rights reserved.