PECAM1 regulates flow-mediated Gab1 tyrosine phosphorylation and signaling.
PECAM1 regulates flow-mediated Gab1 tyrosine phosphorylation and signaling.
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DOI：
10.1016/j.cellsig.2015.12.007
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发表时间：
2016-03
影响因子：
4.8
通讯作者：
Jin ZG
中科院分区：
文献类型：
--
作者：
Xu S;Ha CH;Wang W;Xu X;Yin M;Jin FQ;Mastrangelo M;Koroleva M;Fujiwara K;Jin ZG
内皮功能障碍是多种心血管疾病的常见机制，包括高血压和动脉粥样硬化，其特征在于内皮型一氧化氮合酶（eNOS）的活化受损和随后的NO产生减少。层流介导的特异性信号级联调节血管内皮细胞（EC）的结构和功能。我们以前已经表明，流量刺激的Gab 1（Grb 2相关的结合剂-1）酪氨酸磷酸化介导内皮细胞中的eNOS激活，这在一定程度上赋予层流动脉粥样硬化保护作用。然而，流动调节Gab 1酪氨酸磷酸化及其下游信号事件的分子机制仍不清楚。在这里，我们表明，血小板内皮细胞粘附分子-1（PECAM 1），在内皮mechanosensing复杂的关键分子，具体介导Gab 1酪氨酸磷酸化和下游Akt和eNOS激活EC流动后，而不是肝细胞生长因子（HGF）的刺激。靶向PECAM 1的小干扰RNA（siRNA）阻断了流动诱导的Gab 1酪氨酸磷酸化和Akt、eNOS活化以及Gab 1膜转位，但没有阻断HGF诱导的Gab 1酪氨酸磷酸化和Akt、eNOS活化以及Gab 1膜转位。蛋白酪氨酸磷酸酶SHP 2，已被证明与Gab 1相互作用，参与流动信号和HGF信号，因为SHP 2 siRNA减少了流动和HGF诱导的Gab 1酪氨酸磷酸化，膜定位和下游信号。药理学抑制PI 3 K降低流量，但不是HGF介导的Gab 1磷酸化和膜定位以及eNOS激活。最后，我们观察到，在PECAM 1基因敲除小鼠中，由自愿轮运行诱导的体内流动介导的Gab 1和eNOS磷酸化减少。这些结果证明了PECAM 1在EC中流动介导的Gab 1酪氨酸磷酸化和eNOS信号传导中的特定作用。
Endothelial dysfunction, characterized by impaired activation of endothelial nitric oxide (NO) synthase (eNOS) and ensued decrease of NO production, is a common mechanism of various cardiovascular pathologies, including hypertension and atherosclerosis. Laminar blood flow-mediated specific signaling cascades modulate vascular endothelial cells (ECs) structure and functions. We have previously shown that flow-stimulated Gab1 (Grb2-associated binder-1) tyrosine phosphorylation mediates eNOS activation in ECs, which in part confers laminar flow atheroprotective action. However, the molecular mechanisms whereby flow regulates Gab1 tyrosine phosphorylation and its downstream signaling events remain unclear. Here we show that platelet endothelial cell adhesion molecule-1 (PECAM1), a key molecule in an endothelial mechanosensing complex, specifically mediates Gab1 tyrosine phosphorylation and its downstream Akt and eNOS activation in ECs upon flow rather than hepatocyte growth factor (HGF) stimulation. Small interfering RNA (siRNA) targeting PECAM1 abolished flow- but not HGF-induced Gab1 tyrosine phosphorylation and Akt, eNOS activation as well as Gab1 membrane translocation. Protein-tyrosine phosphatase SHP2, which has been shown to interact with Gab1, was involved in flow signaling and HGF signaling, as SHP2 siRNA diminished the flow- and HGF-induced Gab1 tyrosine phosphorylation, membrane localization and downstream signaling. Pharmacological inhibition of PI3K decreased flow-, but not HGF-mediated Gab1 phosphorylation and membrane localization as well as eNOS activation. Finally, we observed that flow-mediated Gab1 and eNOS phosphorylation in vivo induced by voluntary wheel running was reduced in PECAM1 knockout mice. These results demonstrate a specific role of PECAM1 in flow-mediated Gab1 tyrosine phosphorylation and eNOS signaling in ECs.