Thrombin induces fibroblast CCL2/JE production and release via coupling of PAR1 to Gαq and cooperation between ERK1/2 and Rho kinase signaling pathways
Thrombin induces fibroblast CCL2/JE production and release via coupling of PAR1 to Gαq and cooperation between ERK1/2 and Rho kinase signaling pathways
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DOI：
10.1091/mbc.e07-07-0720
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发表时间：
2008-06-01
影响因子：
3.3
通讯作者：
Chambers, Rachel C.
中科院分区：
文献类型：
--
作者：
Deng, Xiaoling;Mercer, Paul F.;Chambers, Rachel C.
组织损伤后凝血级联的不受控制的激活与炎症和组织纤维化有关。凝血酶通过其高亲和力受体蛋白酶激活受体 1 (PAR(1)) 和通过 G alpha(i/o)、G alpha(q) 或 G alpha(12/13) 的信号传导发挥多能细胞作用。成纤维细胞（纤维化的关键效应细胞）上 PAR1 的激活会诱导多种介质的产生，包括强效单核细胞和纤维细胞趋化剂 CCL2。本研究的目的是鉴定参与 PAR(1) 介导的 CCL2 产生和释放的 G 蛋白和信号通路。使用一种新型 PAR1 拮抗剂阻断 PAR1 和 G α(q) 之间的相互作用，我们首次报道 PAR1 与 G α(q) 的偶联对于小鼠肺成纤维细胞中凝血酶诱导的 CCL2 基因表达和蛋白质释放至关重要。我们进一步证明这些效应是通过 ERK1/2 和 Rho 激酶信号通路之间的协作介导的：发现钙独立蛋白激酶 C (PKC)、c-Raf 和 ERK1/2 通路介导 PAR1 诱导的 CCL2 基因转录，而磷脂酶 C、钙依赖性 PKC 和 Rho 激酶通路影响 CCL2 蛋白释放。我们认为，靶向 PAR1 和 G α(q) 之间的相互作用可能使我们能够选择性地干扰 PAR1 促炎症和促纤维化信号传导，同时保留其他 PAR1 介导的细胞反应的重要作用。
Uncontrolled activation of the coagulation cascade after tissue injury has been implicated in both inflammation and tissue fibrosis. Thrombin exerts pluripotent cellular effects via its high-affinity receptor, proteinase-activated receptor-1 (PAR(1)) and signaling via G alpha(i/o), G alpha(q), or G alpha(12/13). Activation of PAR1 on fibroblasts, a key effector cell in fibrosis, results in the induction of several mediators, including the potent monocyte and fibrocyte chemoattractant CCL2. The aim of this study was to identify the G protein and signaling pathway involved in PAR(1)-mediated CCL2 production and release. Using a novel PAR1 antagonist that blocks the interaction between PAR1 and G alpha(q), we report for the first time that PAR1 coupling to G alpha(q) is essential for thrombin-induced CCL2 gene expression and protein release in murine lung fibroblasts. We further demonstrate that these effects are mediated via the cooperation between ERK1/2 and Rho kinase signaling pathways: a calcium-independent protein kinase C (PKC), c-Raf, and ERK1/2 pathway was found to mediate PAR1-induced CCL2 gene transcription, whereas a phospholipase C, calcium-dependent PKC, and Rho kinase pathway influences CCL2 protein release. We propose that targeting the interaction between PAR1 and G alpha(q) may allow us to selectively interfere with PAR1 proinflammatory and profibrotic signaling, while preserving the essential role of other PAR1-mediated cellular responses.