PDF(Pubmed)
Abstract：
Endothelial cell responses to fluid shear stress from blood flow are crucial for vascular development, function, and disease. A complex of PECAM-1, VE-cadherin, VEGF receptors (VEGFRs), and Plexin D1 located at cell-cell junctions mediates many of these events. However, available evidence suggests that another mechanosensor upstream of PECAM-1 initiates signaling. Hypothesizing that GPCR and Gα proteins may serve this role, we performed siRNA screening of Gα subunits and found that Gαi2 and Gαq/11 are required for activation of the junctional complex. We then developed a new activation assay, which showed that these G proteins are activated by flow. We next mapped the Gα residues required for activation and developed an affinity purification method that used this information to identify latrophilin-2 (Lphn2/ADGRL2) as the upstream GPCR. Latrophilin-2 is required for all PECAM-1 downstream events tested. In both mice and zebrafish, latrophilin-2 is required for flow-dependent angiogenesis and artery remodeling. Furthermore, endothelial-specific knockout demonstrates that latrophilin plays a role in flow-dependent artery remodeling. Human genetic data reveal a correlation between the latrophilin-2-encoding Adgrl2 gene and cardiovascular disease. Together, these results define a pathway that connects latrophilin-dependent G protein activation to subsequent endothelial signaling, vascular physiology, and disease.
摘要：
内皮细胞对来自血流的流体剪切应力的反应对于血管发育至关重要，函数,和疾病。PECAM-1，VE-cadherin的复合物，VEGF受体(VEGFRs),位于细胞-细胞连接处的神经丛蛋白D1介导了许多这些事件。然而,现有证据表明PECAM-1上游的另一个机械传感器启动信号传导。假设GPCR和Gα蛋白可能起到这种作用，我们对Gα亚基进行了siRNA筛选，发现Gαi2和Gαq/11是连接复合物激活所必需的。然后我们开发了一种新的激活检测方法,这表明这些G蛋白被流动激活。接下来，我们绘制了激活所需的Gα残基，并开发了一种亲和纯化方法，该方法使用该信息将latrophilin-2（Lphn2/ADGRL2）鉴定为上游GPCR。所有测试的PECAM-1下游事件都需要Latrophilin-2。在老鼠和斑马鱼中，latrophilin-2是血流依赖性血管生成和动脉重塑所必需的。此外，内皮特异性基因敲除表明latrophilin在血流依赖性动脉重塑中起作用.人类遗传数据揭示了编码latrophilin-2的Adgrl2基因与心血管疾病之间的相关性。一起,这些结果定义了一个连接latrophilin依赖性G蛋白激活与随后的内皮信号传导的途径，血管生理学,和疾病。
