G-protein coupled receptor 15 mediates angiogenesis and cytoprotective function of thrombomodulin.
G-protein coupled receptor 15 mediates angiogenesis and cytoprotective function of thrombomodulin.
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DOI：
10.1038/s41598-017-00781-w
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发表时间：
2017-04-06
影响因子：
4.6
通讯作者：
Ikezoe T
中科院分区：
文献类型：
--
作者：
Pan B;Wang X;Nishioka C;Honda G;Yokoyama A;Zeng L;Xu K;Ikezoe T
血栓调节素（TM）通过其第五表皮生长因子样区（TME5）刺激血管生成并保护血管内皮细胞（ECs）；然而，介导TM激活的促生存信号的细胞表面受体仍然未知。通过下拉实验、MALDI-TOF MS和western blot分析，我们确定了g蛋白偶联受体15 （GPR15）是TME5的结合伙伴。TME5可恢复野生型（WT） C57BL/6小鼠血管内皮细胞中钙调磷酸酶抑制剂FK506引起的生长抑制和凋亡。另一方面，TME5不能保护GPR15敲除（GPR15 KO）小鼠分离的ECs免受fk506引起的血管损伤。TME5以GPR15依赖的方式诱导细胞外信号调节激酶（ERK）的激活和抗凋亡蛋白水平的升高。此外，体内Matrigel塞血管生成实验发现，TME5刺激小鼠血管生成。TME5促进体外内皮细胞迁移。此外，TME5增加了内皮细胞NO合成酶（eNOS）的生成。敲除GPR15后，TME5的这些促血管生成功能均被消除。我们的研究结果表明，GPR15在介导TM的细胞保护功能和血管生成中起重要作用。
Thrombomodulin (TM) stimulates angiogenesis and protects vascular endothelial cells (ECs) via its fifth epidermal growth factor-like region (TME5); however, the cell surface receptor that mediates the pro-survival signaling activated by TM has remained unknown. We applied pull-down assay followed by MALDI-TOF MS and western blot analysis, and identified G-protein coupled receptor 15 (GPR15) as a binding partner of TME5. TME5 rescued growth inhibition and apoptosis caused by calcineurin inhibitor FK506 in vascular ECs isolated from wild type (WT) C57BL/6 mice. On the other hand, TME5 failed to protect ECs isolated from GPR15 knockout (GPR15 KO) mice from FK506-caused vascular injury. TME5 induced activation of extracellular signal-regulated kinase (ERK) and increased level of anti-apoptotic proteins in a GPR15 dependent manner. In addition, in vivo Matrigel plug angiogenesis assay found that TME5 stimulated angiogenesis in mice. TME5 promoted endothelial migration in vitro. Furthermore, TME5 increased production of NO in association with activated endothelial NO synthase (eNOS) in ECs. All these pro-angiogenesis functions of TME5 were abolished by knockout of GPR15. Our findings suggest that GPR15 plays an important role in mediating cytoprotective function as well as angiogenesis of TM.