大鼠肺动脉平滑肌细胞缺氧后STAT3活性变化对细胞癌基因c-jun mRNA表达及细胞增殖的影响  

Effects of activated STAT3 on c-jun mRNA expression and proliferation of pulmonary arterial smooth muscle cells under hypoxia in rats

作　　者：白莉[1] 余祖滨[2] 钱频[3] 钱桂生[1] 关崧[1] 

机构地区：[1]第三军医大学新桥医院全军呼吸内科研究所,全军呼吸病研究重点实验室 [2]第三军医大学新桥医院胸外科,重庆400037 [3]第三军医大学新桥医院超声诊断科,重庆400037

出　　处：《第三军医大学学报》2005年第11期1093-1096,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金资助项目 ( 39970 32 9)~~

摘　　要：目的　观察大鼠肺动脉平滑肌细胞缺氧后信号转导和转录活化因子3 (STAT3 )活性变化对细胞癌基因c junmRNA表达及细胞增殖的影响。方法　组织块法原代培养肺动脉平滑肌细胞(PASMCs) ,用AG490预孵育后进行缺氧处理,Westernblot检测缺氧2、4、6、8、12h组STAT3酪氨酸活性水平变化;半定量RT PCR检测缺氧2、4、6、8、12h组细胞中c junmRNA表达水平变化;流式细胞仪检测细胞周期变化。结果　Westernblot定量分析示缺氧培养6h组STAT3酪氨酸磷酸化水平升高,12h组达高峰;缺氧2h细胞c junmRNA表达升高,6h达高峰,8h下降;细胞在缺氧6h出现G0 G1 期细胞比例明显减少,S +G2 M期细胞比例明显增加,并随缺氧时间延长变化更显著。与对照组细胞相比,AG490处理组细胞在缺氧各时相点STAT3酪氨酸磷酸化水平及c junmRNA表达明显降低,同时G0 G1 期细胞比例显著增加,S +G2 M期细胞比例显著减少。结论　①STAT3活化和c junmRNA表达增加参与缺氧PASMCs增殖;②AG490可通过抑制STAT3活性下调c junmRNA表达,从而抑制缺氧诱导的PASMCs增殖。Objective To study the effects of activated signal transduction and activators of transcription 3 (STAT3) on c-jun mRNA expression and proliferation of pulmonary arterial smooth muscle cells (PASMCs) under hypoxia in rats. Methods After PASMCs were cultured with AG490 and exposed to hypoxia, the tyrosin-phosphorylated STAT3 protein was determined in the 2 nd , 4 th , 6 th , 8 th and 12 th hour after hypoxic exposure with Western blotting. The expression of c-jun mRNA was observed with sqRT-PCR. Flow cytometric DNA analysis was used to observe the cell cycles. Results The level of tyrosin-phosphorylated STAT3 began to increase in the 6 th hour after hypoxic exposure and reached the peak of increase in the 12 th hour. The level of tyrosine-phosphorylated STAT3 and c-jun expression mRNA in the AG490-treated PASMCs was significantly lower than that in the control group. The AG490-treated PASMCs were increased in G 1/G 0 phase and decreased in the S+G 2/M phase under normoxic and hypoxic conditions. Conclusion The activated STAT3 and c-jun gene might play an important role in the early stage of hypoxia-induced proliferation of PASMCs. AG490 might inhibit c-jun expression through the lowering of the level of tyrosine phosphorylation of STAT3 which prevents the proliferation of hypoxia-induced proliferation of PASMCs.

关 键 词：缺氧 信号传导 肺动脉 平滑肌细胞 细胞癌基因 增殖 

分 类 号：R322.121[医药卫生—人体解剖和组织胚胎学] R329.2[医药卫生—基础医学]