G protein-coupled receptors activate p38 MAPK via a non-canonical TAB1-TAB2-and TAB1-TAB3-dependent pathway in endothelial cells
G protein-coupled receptors activate p38 MAPK via a non-canonical TAB1-TAB2-and TAB1-TAB3-dependent pathway in endothelial cells
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DOI：
10.1074/jbc.ra119.007495
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发表时间：
2019-04-12
影响因子：
4.8
通讯作者：
Trejo, JoAnn
中科院分区：
文献类型：
--
作者：
Grimsey, Neil J.;Lin, Ying;Trejo, JoAnn
内皮功能障碍是由炎症介质引起的，其中包括多种G蛋白偶联受体激动剂。然而，促进内皮功能障碍的GPCR信号通路还不完全清楚。我们先前的研究表明，凝血酶通过非规范的转化生长因子活化蛋白激酶-1结合蛋白-1(TAB1)和TAB2依赖的途径，而不是典型的三级激酶级联途径，通过自磷酸化和激活p38丝裂原活化蛋白激酶(MAPK)来促进内皮屏障的破坏。在这里，我们试图确定是否其他GPCR激动剂通过这一非规范途径刺激来自不同血管床的人内皮细胞中p38 MAPK的激活。利用原代人脐静脉内皮细胞(HUVECs)、HUVEC来源的EA.hy926细胞和人真皮微血管内皮细胞(HDMECs)，我们发现在这些不同类型的内皮细胞中都表达非规范和规范的p38激活通路成分，包括结构上相关的TAB2同源物Tab3。此外，包括凝血酶、组胺、前列腺素E-2和ADP在内的多种GPCRs激动剂可刺激强大的p38自动磷酸化，而上游MAPKs MAPK3(MKK3)和MKK6的磷酸化几乎检测不到，这表明其他GPCRs可能存在非典型的p38激活。事实上，在EA.hy926细胞中，凝血酶和组胺刺激的p38激活依赖于Tab1-Tab2，而在原代HUVEC中，Tab1-Tab2和Tab1-Tab3都是激活p38所必需的。在HDMEC中，凝血酶诱导的p38激活依赖于Tab1-Tab3，但组胺诱导的p38激活需要Tab1-Tab2。此外，凝血酶和组胺刺激HUVEC产生白介素6需要TAB1-TAB2和TAB1-TAB3。我们得出结论，多种GPCR激动剂利用非规范的TAB1-TAB2和TAB1-TAB3依赖的p38激活来促进内皮炎性反应。
Endothelial dysfunction is induced by inflammatory mediators including multiple G protein-coupled receptor (GPCR) agonists. However, the GPCR signaling pathways that promote endothelial dysfunction are incompletely understood. We previously showed that thrombin promotes endothelial barrier disruption through autophosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) via a non-canonical transforming growth factor--activated protein kinase-1-binding protein-1 (TAB1) and TAB2-dependent pathway rather than the canonical three-tiered kinase cascade. Here, we sought to determine whether other GPCR agonists stimulate p38 MAPK activation via this non-canonical pathway in human endothelial cells derived from different vascular beds. Using primary human umbilical vein endothelial cells (HUVECs), HUVEC-derived EA.hy926 cells, and human dermal microvascular endothelial cells (HDMECs), we found that both non-canonical and canonical p38 activation pathways components are expressed in these various endothelial cell types, including TAB3, a structurally-related TAB2 homolog. Moreover, multiple GPCRs agonists, including thrombin, histamine, prostaglandin E-2, and ADP, stimulated robust p38 autophosphorylation, whereas phosphorylation of the upstream MAPKs MAP kinase kinase 3 (MKK3) and MKK6, was virtually undetectable, indicating that non-canonical p38 activation may exist for other GPCRs. Indeed, in EA.hy926 cells, thrombin- and histamine-stimulated p38 activation depended on TAB1-TAB2, whereas in primary HUVECs, both TAB1-TAB2 and TAB1-TAB3 were required for p38 activation. In HDMECs, thrombin-induced p38 activation depended on TAB1-TAB3, but histamine-induced p38 activation required TAB1-TAB2. Moreover, thrombin- and histamine-stimulated interleukin-6 production required both TAB1-TAB2 and TAB1-TAB3 in HUVEC. We conclude that multiple GPCR agonists utilize non-canonical TAB1-TAB2 and TAB1-TAB3-dependent p38 activation to promote endothelial inflammatory responses.