信号转导子和激活子3通路调控大鼠血管平滑肌细胞增殖迁移机制研究

目的研究转录信号转导子和激活子3（stat3）通路与大鼠血管平滑肌细胞（VSMCs）增殖迁移的关系,明确VSMCs增殖的信号转导过程。方法应用脂质体转染Stat3反义寡核苷酸作用于大鼠VSMCs,应用酶联免疫法（ELISA）检测Stat3水平变化及MTF法检测细胞增殖状态,蛋白免疫印迹法（Western blot）检测stat3、磷酸化stat3及其靶基因产物Cyclin D1、Bcl—XL的表达。结果转染Stat3反义寡核苷酸后,大鼠VSMCs中Stat3水平明显下降（P〈0．01）,同时其增殖水平降低,而相应空白对照组、脂质体组、转染正义寡核苷酸组变化不明显。转染Stat3反义寡核苷酸的VSMCs中stat3、p-Stat 3、Cyclin D1蛋白表达水平随作用时间延长而下降（P〈0．01）,而Bcl—xL水平无明显变化。结论癌基因stat3信号通路与大鼠VSMCs增殖高度相关,可能通过其下游靶基因Cyclin D1影响其增殖,而阻断此通路则可抑制VSMCs的增殖。

Stat 3 signal transduction pathway correlates with proliferation of vascular smooth muscle cells of rats

OBJECTIVE: To investigate the role of Stat3 (one of the signal transductant and activator) signal transduction pathway in proliferation of vascular smooth muscle cells (VSMCs). METHODS: VSMC was transfected with Stat3 antisense oligonucleotide. ELISA analysis was performed on Stat3 expression in cultured rat thoracic VSMC. Cell proliferation and toxicity assay by Methyl Thiazole (MTT) was used to measure the cell proliferation. The expression of Stat3, p-Stat3, Cyclin D1 and Bcl-x(L) were measured by Western blot. RESULTS: Stat3 protein expression was positive in VSMC. Targeting of Stat3 using antisense oligonucleotide directed against the translation site, resulted in significant growth inhibition and downregulation of Stat3, p-Stat3 and Cyclin D1. CONCLUSIONS: The increase of Stat3 correlates significantly with cell proliferation of VSMC. Cyclin D1 may be the critical target gene in mediating proliferation. Blocking Stat3 signal transduction pathway may inhibit the growth of VSMCs.