The purpose of this study was to investigate the regulatory role of tyrosine kinase 2 with immunoglobulin-like and epidermal growth factor homology domains (Tie2) on apoptosis and proliferation in the endothelial cells. Methods RNA interference (RNAi) technique was used to silence Tie2 gene expression by transfecting an expression vector containing short hairpin RNACshRNA) for Tie2 into human umbilical vein endothelial cells (HUVECs). Real time quantitation reverse transcriptase polymerase chain reaction (QRT-PCR) and Western blot were used to monitor Tie2 mRNA, as well as protein expression. The proliferation of HUVECs was examined by methyl thiazolyl tetrazolium (MTT), and the apoptosis was detected under microscope. HUVECs transfected with pGenesil-hk was negative control, and HUVECs transfected with nothing was empty control. Results Tie2 mRNA expression was down-regulated 24 h and 48 h after transfection, and Tie2 protein expression was significantly down-regulated at 24 h and 48 h (P< 0.05), especially 48 h after transfection. The apoptosis rate was conspicuously higher in experimental group than in negative control and empty control group after 48 h (P<0.05). The growth monitoring showed that proliferation was also markedly inhibited in experimental group (P<0.05) compared with two control groups. Conclusion Down-regulated expression of Tie2 by RNAi can promotes apoptosis of HUVECs and has an anti-proliferation activity effect on them.%目的 研究抑制酪氨酸激酶受体2 (Tie2)对内皮细胞凋亡和增殖活性的影响.方法 采用RNA干扰技术,将含有Tie2基因的特异性短发夹状RNA (shRNA)片段的质粒转染入人脐静脉内皮细胞(HUVECs),采用实时定量逆转录聚合酶链反应和免疫印迹法检测细胞中Tie2 mRNA和蛋白表达的改变；噻唑蓝比色分析(MTT)法检测细胞的生长情况；显微镜下观察细胞凋亡情况.以转染了pGenesil-hk质粒组为阴性对照,未转染质粒组为空白对照.结果 质粒转染入HUVECs后,实验组细胞中Tie2 mRNA和蛋白表达水平较阴性对照组和空白对照组下调,尤以转染后48 h Tie2的mRNA和蛋白表达水平下调更为明显(P＜0.05).MTT检测结果显示:实验组细胞的增殖活性受到明显抑制(P＜0.05).转染48 h后,实验组的细胞凋亡率明显高于两个对照组(P＜0.05).结论 RNA干扰技术沉默Tie2基因可致Tie2基因表达下调后诱导HUVECs凋亡,并抑制HUVECs的增殖.
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