动脉平滑肌细胞STIM1过表达上调Akt/mTOR通路并促进细胞增殖

STIM1 promotes arterial smooth muscle cells proliferation by regulating Akt/m TOR pathway

目的观察基质相互作用分子1(stromal interaction molecule 1,STIM1)在肺动脉高压组织中的表达,并探讨STIM1对动脉平滑肌细胞增殖的影响及机制。方法一次性腹腔注射野百合碱(MCT)建立肺动脉高压大鼠模型;实时定量PCR和蛋白印迹分别测定肺动脉高压大鼠肺组织STIM1 mRNA和蛋白的表达;采用基因转染技术建立STIM1瞬时高表达的动脉平滑肌A7R5细胞模型;用CCK-8法测定细胞增殖能力;用蛋白印迹测定Akt/m TOR通路分子的表达。结果与对照组相比,MCT组的右心室收缩压(RVSP)和右心重量指数(RVMI)均明显增高(P<0.01),形态学观察可见肺小动脉平滑肌层明显增厚,管腔减小;MCT组大鼠STIM1 mRNA和蛋白表达量分别是对照大鼠的2.19和1.66倍;STIM1瞬时过表达的动脉平滑肌细胞与对照组相比,生长速度加快;STIM1过表达可明显增加Akt、m TOR、p70-S6K和4E-BP1的磷酸化水平,而对它们的蛋白水平没有影响。结论肺动脉高压发病中存在STIM1的过表达,STIM1可促进动脉平滑肌细胞增殖,其机制与上调Akt/mT OR信号转导通路相关。

Aim To investigate the expression of stromal interaction molecule 1( STIM1) in rat pulmonary arterial hypertension( PAH) tissues and effects of STIM1 on arterial muscle cells proliferation. Methods PAH was induced by a single intraperitoneal injection of MCT at a dose of 60 mg·kg- 1. The mRNA or protein expressions of STIM1 in monocrotaline-induced pulmonary hypertensive rats were measured by realtime PCR or Western blot,respectively. The arterial smooth muscle cells A7R5 were transiently transfected with STIM1 plasmids to prepare STIM1 overexpressed cells. Cell proliferations were detected by using CCK-8kits. The expressions of Akt / mT OR pathway molecules of A7R5 were measured by Western blot. Results The right ventricular systolic blood pressure( RVSP)and right ventricular mass index( RVMI) were markedly elevated in MCT-treated rats( P < 0. 01) incomparison to control rats. The mRNA and protein expression levels of STIM1 in monocrotaline-induced pulmonary hypertensive rats were 2. 19 and 1. 66 folds of control rats,respectively. STIM1 were transiently overexpressed in cultured A7R5. Cells transfected with STIM1 grew more quickly than non-transfected control.Overexpression of STIM1 significantly increased the phosphorylation of Akt,mT OR,p70-S6 K,and 4EBP1,but did not change their protein expression levels. Conclusion STIM1 are over-expressed in rat PAH tissues. Overexpression of STIM1 can promote arterial smooth muscle cells proliferation by regulating Akt / mT OR pathway.