Inhibitory effect of calcitonin gene-related peptide on hypoxia-induced rat pulmonary artery smooth muscle cells proliferation: Role of ERK1/2 and p27
Inhibitory effect of calcitonin gene-related peptide on hypoxia-induced rat pulmonary artery smooth muscle cells proliferation: Role of ERK1/2 and p27
复制标题
降钙素基因相关肽对缺氧诱导的大鼠肺动脉平滑肌细胞增殖的抑制作用：ERK1/2和p27的作用
DOI：
10.1016/j.ejphar.2012.01.015
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发表时间：
2012-03-15
影响因子：
5
通讯作者：
Li, Yuan-Jian
中科院分区：
文献类型：
--
作者：
Li, Xian-Wei;Hu, Chang-Ping;Li, Yuan-Jian
降钙素基因相关肽（CGRP）通过灭活细胞外信号调节蛋白激酶1/2（ERK 1/2）抑制血管紧张素II诱导的主动脉平滑肌细胞增殖。ERK 1/2是降解或下调细胞周期抑制因子p27所必需的，并且在介导肺动脉平滑肌细胞（PASMCs）的增殖中也是至关重要的。ERK 1/2/p27信号通路是否参与CGRP介导的肺动脉高压和血管重构的发病机制尚不清楚。在大鼠中通过缺氧诱导肺动脉高压，并且在大鼠中加入辣椒素（50 mg/kg，s.c.）用于消耗内源性CGRP。用BrdU掺入法和流式细胞术检测培养的PASMCs增殖情况。采用放射免疫法、免疫组化法、实时荧光定量PCR法和Western blot法检测CGRP、p27、ERK 1/2、c-fos和c-myc的表达水平。辣椒素耗竭CGRP可加重大鼠缺氧性肺动脉高压，表现为右心室收缩压、平均肺动脉压升高和血管肥厚，并伴有p27表达降低和磷酸化ERK 1/2、c-fos和c-myc表达增加。外源性CGRP可显著抑制低氧诱导的PASMCs增殖，同时p27表达增加，磷酸化ERK 1/2、c-fos和c-myc表达降低。CGRP的这些作用在存在CGRP的情况下被消除（8-37）。p27基因敲除可逆转CGRP对PASMCs增殖及c-fos、c-myc表达的抑制作用，但对ERK 1/2磷酸化无明显影响。提示CGRP通过ERK 1/2/p27/c-fos/c-myc信号通路抑制低氧诱导的PASMCs增殖。CGRP下调可能参与了缺氧性肺动脉高压肺动脉重构。(C)2012 Elsevier B. V.保留所有权利。
Calcitonin gene-related peptide (CGRP) inhibits angiotensin II-induced proliferation of aortic smooth muscle cells via inactivation of extracellular signal-regulated protein kinase 1/2 (ERK1/2). ERK1/2 is necessary for the degradation or down-regulation of the cell cycle inhibitor p27, and is also crucial in mediating proliferation of pulmonary artery smooth muscle cells (PASMCs). Whether ERK1/2/p27 signal pathway is involved in CGRP-mediated pathogenesis of pulmonary hypertension and vascular remodeling remains unknown. Pulmonary hypertension was induced by hypoxia in rats, and capsaicin (50 mg/kg, s.c.) was used to deplete endogenous CGRP. Proliferation of cultured PASMCs was determined by BrdU incorporation method and flow cytometry. The expression/level of CGRP, p27, ERK1/2, c-fos and c-myc was analyzed by radioimmunoassay, immunohistochemistry, real-time PCR or Western blot. Sensory CGRP depletion by capsaicin exacerbated hypoxia-induced pulmonary hypertension in rats, as shown by an increase in right ventricle systolic pressure, mean pulmonary artery pressure and vascular hypertrophy, accompanied with decreased p27 expression and increased expression of phosphorylated ERK1/2, c-fos and c-myc. Exogenous application of CGRP significantly inhibited hypoxia-induced proliferation of PASMCs concomitantly with increased p27 expression and decreased expression of phosphorylated ERK1/2, c-fos and c-myc. These effects of CGRP were abolished in the presence of CGRP(8-37). Knockdown of p27 also reversed the inhibitory effect of CGRP on proliferation of PASMCs and expression of c-fos and c-myc, but not on ERK1/2 phosphorylation. These results suggest that CGRP inhibits hypoxia-induced proliferation of PASMCs via ERK1/2/p27/c-fos/c-myc pathway. Downregulation of CGRP may contribute to remodeling of pulmonary arteries in hypoxia-induced pulmonary hypertension. (C) 2012 Elsevier B.V. All rights reserved.