Hypoxia alters biophysical properties of endothelial cells via p38 MAPK- and Rho kinase-dependent pathways
Hypoxia alters biophysical properties of endothelial cells via p38 MAPK- and Rho kinase-dependent pathways
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DOI：
10.1152/ajpcell.00429.2004
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发表时间：
2005-09-01
影响因子：
5.5
通讯作者：
Kayyali, US
中科院分区：
文献类型：
--
作者：
An, SS;Pennella, CM;Kayyali, US
缺氧会改变肺血管内皮细胞的屏障功能，但潜在的生物物理机制仍不清楚。使用培养的大鼠肺微血管内皮细胞（RPMEC），我们在此报告了因缺氧而发生的生物物理特性在空间和时间上的变化。我们还探讨了这些变化的分子基础。在单细胞水平上，我们测量了细胞硬度、细胞对其基底施加的牵引力的分布，以及与细胞骨架 (CSK) 紧密结合的微珠的自发纳米级运动。缺氧通过依赖于 Rho 激酶激活的机制增加细胞硬度和牵引力。这些变化之后是 p38 介导的自发珠运动减少，表明局部细胞-细胞外基质 (ECM) 束缚相互作用的稳定。过度表达磷酸模拟小热休克蛋白 (HSP27-PM)（p38 的下游效应子）的细胞表现出自发珠运动的减少，这与这些细胞中肌动蛋白聚合的增加相关。总之，这些发现表明缺氧对内皮细胞收缩和细胞-ECM 粘附有不同的调节作用。
Hypoxia alters the barrier function of the endothelial cells that line the pulmonary vasculature, but underlying biophysical mechanisms remain unclear. Using rat pulmonary microvascular endothelial cells (RPMEC) in culture, we report herein changes in biophysical properties, both in space and in time, that occur in response to hypoxia. We address also the molecular basis of these changes. At the level of the single cell, we measured cell stiffness, the distribution of traction forces exerted by the cell on its substrate, and spontaneous nanoscale motions of microbeads tightly bound to the cytoskeleton ( CSK). Hypoxia increased cell stiffness and traction forces by a mechanism that was dependent on the activation of Rho kinase. These changes were followed by p38-mediated decreases in spontaneous bead motions, indicating stabilization of local cellular-extracellular matrix (ECM) tethering interactions. Cells overexpressing phospho-mimicking small heat shock protein ( HSP27-PM), a downstream effector of p38, exhibited decreases in spontaneous bead motions that correlated with increases in actin polymerization in these cells. Together, these findings suggest that hypoxia differentially regulates endothelial cell contraction and cellular-ECM adhesion.