Rho guanine nucleotide exchange factors involved in cyclic-stretch-induced reorientation of vascular endothelial cells
Rho guanine nucleotide exchange factors involved in cyclic-stretch-induced reorientation of vascular endothelial cells
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DOI：
10.1242/jcs.157503
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发表时间：
2015-05-01
影响因子：
4
通讯作者：
Mizuno, Kensaku
中科院分区：
文献类型：
--
作者：
Abiko, Hiyori;Fujiwara, Sachiko;Mizuno, Kensaku
循环拉伸是一种机械力加载的人工模型，它诱导血管内皮细胞及其应力纤维在垂直于拉伸轴的方向上重新定向。Rho家族gtpase对循环拉伸诱导的内皮细胞重定向至关重要；然而，拉伸诱导Rho家族GTPases激活的机制尚不清楚。一项针对63个Rho鸟苷核苷酸交换因子（Rho- gefs）的短发夹rna的筛选显示，至少有11个Rho- gefs - Abr、alsin、ARHGEF10、Bcr、GEF-H1（也称为ARHGEF2）、LARG（也称为ARHGEF12）、p190RhoGEF（也称为ARHGEF28）、PLEKHG1、P-REX2、Solo（也称为ARHGEF40）和α - pix（也称为ARHGEF6）特异性或广泛靶向RhoA、Rac1和/或Cdc42，参与了循环拉伸诱导的内皮细胞垂直定向。过表达Solo诱导RhoA活化和f -肌动蛋白积聚在细胞-细胞和细胞-底物粘附位点。敲低Solo抑制循环拉伸或拉伸力诱导的RhoA激活。此外，当细胞在高密度培养时，敲低Solo显著降低了循环拉伸诱导的内皮细胞垂直重定向，但当细胞在低密度培养或用EGTA或ve -cadherin靶向小干扰rna预处理时，则没有。这些结果表明，在循环拉伸诱导的内皮细胞重定向过程中，Solo参与了细胞-细胞粘附介导的机械信号转导。
Cyclic stretch is an artificial model of mechanical force loading, which induces the reorientation of vascular endothelial cells and their stress fibers in a direction perpendicular to the stretch axis. Rho family GTPases are crucial for cyclic-stretch-induced endothelial cell reorientation; however, the mechanism underlying stretch-induced activation of Rho family GTPases is unknown. A screen of short hairpin RNAs targeting 63 Rho guanine nucleotide exchange factors (Rho-GEFs) revealed that at least 11 Rho-GEFs - Abr, alsin, ARHGEF10, Bcr, GEF-H1 (also known as ARHGEF2), LARG (also known as ARHGEF12), p190RhoGEF (also known as ARHGEF28), PLEKHG1, P-REX2, Solo (also known as ARHGEF40) and alpha-PIX (also known as ARHGEF6) - which specifically or broadly target RhoA, Rac1 and/or Cdc42, are involved in cyclic-stretch-induced perpendicular reorientation of endothelial cells. Overexpression of Solo induced RhoA activation and F-actin accumulation at cell-cell and cell-substrate adhesion sites. Knockdown of Solo suppressed cyclic-stretch- or tensile-force-induced RhoA activation. Moreover, knockdown of Solo significantly reduced cyclic-stretch-induced perpendicular reorientation of endothelial cells when cells were cultured at high density, but not when they were cultured at low density or pretreated with EGTA or VE-cadherin-targeting small interfering RNAs. These results suggest that Solo is involved in cell-cell-adhesion-mediated mechanical signal transduction during cyclic-stretch-induced endothelial cell reorientation.