Thrombospondin-1 regulates blood flow via CD47 receptor-mediated activation of NADPH oxidase 1.
Thrombospondin-1 regulates blood flow via CD47 receptor-mediated activation of NADPH oxidase 1.
复制标题
血小板传播1通过CD47受体介导的NADPH氧化酶1的激活调节血液流动。
DOI：
10.1161/atvbaha.112.300031
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发表时间：
2012-12
期刊：
影响因子：
--
通讯作者：
Pagano PJ
中科院分区：
文献类型：
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作者：
Csányi G;Yao M;Rodríguez AI;Al Ghouleh I;Sharifi-Sanjani M;Frazziano G;Huang X;Kelley EE;Isenberg JS;Pagano PJ
虽然基质细胞蛋白血小板反应蛋白-1（TSP 1）在血管壁中高度表达以响应损伤，但其在血管疾病发展中的病理生理作用知之甚少。本研究旨在验证TSP 1刺激血管平滑肌细胞（VSMCs）产生活性氧（ROS）并通过促进氧化应激诱导血管功能障碍的假设。通过细胞色素c和电子顺磁共振测量，在人类血管疾病中发现的纳摩尔浓度的TSP 1在细胞和组织水平上强烈刺激VSMC中的超氧化物（O2·-）水平。一种模拟已知特异性结合CD 47的TSP 1 C末端的肽重现了这种反应。转录敲低CD 47和单克隆抑制性CD 47抗体在体外和离体消除了TSP 1触发的O2·−。TSP 1处理VSMC激活磷脂酶C和蛋白激酶C，导致NADPH氧化酶（Nox）组织者亚基p47 phox磷酸化和随后的Nox 1激活，导致离体动脉血管舒张受损。此外，我们观察到，在大鼠体内阻断CD 47和Nox 1基因沉默可改善缺血再灌注后TSP 1诱导的组织血流损伤。我们的数据表明，通过直接的TSP 1/CD 47介导的Nox 1激活促进ROS刺激和血流调节的高度调节过程。这是第一次报告，我们的知识的基质细胞蛋白作为一个Nox活化的配体，并通过整合素相关蛋白CD 47的具体参与。
Although the matricellular protein thrombospondin-1 (TSP1) is highly expressed in the vessel wall in response to injury, its pathophysiological role in the development of vascular disease is poorly understood. This study was designed to test the hypothesis that TSP1 stimulates reactive oxygen species (ROS) production in vascular smooth muscle cells (VSMCs) and induces vascular dysfunction by promoting oxidative stress. Nanomolar concentrations of TSP1 found in human vascular disease robustly stimulated superoxide (O2•-) levels in VSMCs at both cellular and tissue level as measured by cytochrome c and electron paramagnetic resonance. A peptide mimicking the C‐terminus of TSP1 known to specifically bind CD47 recapitulated this response. Transcriptional knockdown of CD47 and a monoclonal inhibitory CD47 antibody abrogated TSP1-triggered O2•− in vitro and ex vivo. TSP1-treatment of VSMCs activated phospholipase C and protein kinase C, resulting in phosphorylation of the NADPH oxidase (Nox) organizer subunit p47phox and subsequent Nox1 activation, leading to impairment of arterial vasodilatation ex vivo. Further, we observed that blockade of CD47 and Nox1 gene silencing in vivo in rats improves TSP1-induced impairment of tissue blood flow following ischemia reperfusion. Our data suggest a highly-regulated process of ROS stimulation and blood flow regulation promoted through a direct TSP1/CD47-mediated activation of Nox1. This is the first report to our knowledge of a matricellular protein acting as a ligand for Nox activation and through specific engagement of integrin-associated protein CD47.