Shear-induced tyrosine phosphorylation in endothelial cells requires Rac1-dependent production of ROS.
Shear-induced tyrosine phosphorylation in endothelial cells requires Rac1-dependent production of ROS.
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DOI：
10.1152/ajpcell.1999.276.4.c838
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发表时间：
1999-04
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影响因子：
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通讯作者：
Li-Hong Yeh;Young J. Park;Riple J. Hansalia;Imraan S. Ahmed;S. Deshpande;Pascal J. Goldschmidt-Clermont;K. Irani;B. R. Alevriadou
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作者：
Li-Hong Yeh;Young J. Park;Riple J. Hansalia;Imraan S. Ahmed;S. Deshpande;Pascal J. Goldschmidt-Clermont;K. Irani;B. R. Alevriadou
剪切诱导的血管内皮细胞内信号转导途径涉及酪氨酸磷酸化和丝裂原活化蛋白（MAP）激酶的激活，这可能是负责持续释放一氧化氮。已知MAP激酶在几种细胞类型中被活性氧（ROS）如H2 O2激活。在配体刺激的非吞噬细胞中的ROS产生似乎需要Ras相关的小GTP结合蛋白Rac 1的参与。我们假设Rac 1可能作为一个介质的剪切应力对MAP激酶激活的影响。牛主动脉内皮细胞暴露于20达因/厘米2的层流剪切应力5-30分钟刺激总细胞和胞质酪氨酸磷酸化以及酪氨酸磷酸化的MAP激酶。用抗氧化剂N-乙酰半胱氨酸和吡咯烷二硫代氨基甲酸酯处理内皮细胞以剂量依赖性方式抑制剪切刺激的总胞质增加，特别是MAP激酶酪氨酸磷酸化。因此，剪切应力的发生引起细胞内ROS的产生增强，如氧化蛋白检测试剂盒所证明的，这是剪切诱导的总细胞和MAP激酶酪氨酸磷酸化所需的。总细胞和MAP激酶酪氨酸磷酸化完全阻断剪切牛主动脉内皮细胞表达显性负Rac 1基因产物（N17 rac 1）。我们的结论是，在生理和病理情况下，GTTRIPRac 1介导的剪切诱导的酪氨酸磷酸化的MAP激酶通过调节内皮细胞中的流量依赖性氧化还原变化。
The shear-induced intracellular signal transduction pathway in vascular endothelial cells involves tyrosine phosphorylation and activation of mitogen-activated protein (MAP) kinase, which may be responsible for the sustained release of nitric oxide. MAP kinase is known to be activated by reactive oxygen species (ROS), such as H2O2, in several cell types. ROS production in ligand-stimulated nonphagocytic cells appears to require the participation of a Ras-related small GTP-binding protein, Rac1. We hypothesized that Rac1 might serve as a mediator for the effect of shear stress on MAP kinase activation. Exposure of bovine aortic endothelial cells to laminar shear stress of 20 dyn/cm2 for 5-30 min stimulated total cellular and cytosolic tyrosine phosphorylation as well as tyrosine phosphorylation of MAP kinase. Treating endothelial cells with the antioxidants N-acetylcysteine and pyrrolidine dithiocarbamate inhibited in a dose-dependent manner the shear-stimulated increase in total cytosolic and, specifically, MAP kinase tyrosine phosphorylation. Hence, the onset of shear stress caused an enhanced generation of intracellular ROS, as evidenced by an oxidized protein detection kit, which were required for the shear-induced total cellular and MAP kinase tyrosine phosphorylation. Total cellular and MAP kinase tyrosine phosphorylation was completely blocked in sheared bovine aortic endothelial cells expressing a dominant negative Rac1 gene product (N17rac1). We concluded that the GTPase Rac1 mediates the shear-induced tyrosine phosphorylation of MAP kinase via regulation of the flow-dependent redox changes in endothelial cells in physiological and pathological circumstances.