人外周血活化淋巴细胞中Survivin蛋白表达的分子机制研究

The molecular mechanism of survivin expression in activated human peripheral lymphocytes

目的:探讨活化淋巴细胞中Survivin蛋白诱导表达的信号转导通路、分子级联反应和生物效应,揭示Survivin蛋白表达调控的分子机制。方法:用PHA和rhIL-2刺激培养人外周血单个核细胞,附加JAK抑制剂—AG490的处理,以Western blot检测Survivin和相关蛋白的表达;以流式细胞术(FCM)分析细胞周期和细胞分裂增殖。结果:刺激培养的细胞按照时序先后出现的分子和细胞学反应为:Stat3和Stat5磷酸化→CyclinD3、CyclinE蛋白水平上调→细胞进入S期及Survivin蛋白起始表达→细胞有丝分裂及Survivin蛋白表达水平增加。AG490对于上述反应均呈现明显的抑制作用,但对周期抑制蛋白P21和抗凋亡蛋白Bcl-2的表达水平没有影响。结论:Survivin蛋白的表达依赖JAK-Stat信号转导通路的早期活化,通过上调CyclinD3和CyclinE周期蛋白水平,启动细胞周期的运行,诱导Survivin蛋白的周期时相依赖性表达,参与细胞有丝分裂与增殖。

AIM： investigate the molecular mechanism of regulating survivin expression and related signal transduction pathway, molecular cascade reaction and biological effects in activated PBMC. METHODS. The expression of survivin and related proteins were detected by Western blot in PBMC stimulated by PHA and rhlL-2 with or without JAK inhibitor-AG490 treatment, and FCM was performed to analyze cell cycle and cell division. RESULTS. Our results indicated that molecular and cellular reactions in PBMC activated by PHA and rhlL-2 were dependent on time series. At first, the phosphorylation of Stal3 and Star5 were observed, then, protein levels of CyclinD3 and CyclinE increased, and the stimulated PBMC began to enter to S phage with survivin protein expression was initiated, which at last resulted in cell division with dramatically increasing expression of survivin protein. AG490 could significantly inhibit all these reactions but had no effect on the expressions of the cell cycle inhibitor-P21 and anti-apoptceis protein-Bcl-2. CONCLUSION： The expression of survivin in stimulated PBMC was depend- ent on the primarily activated JAK-STAT pathway, which up- regulated CyclinD3 and CyclinE protein levels, initiated the cell cycle progression, and induced cell cycle-dependent survivin expression, and so survivin was involved in cell division and cell proliferation.