γ-分泌酶抑制剂对人脐静脉内皮细胞系增殖凋亡的影响

目的探讨Notch信号特异性阻断剂γ-分泌酶抑制剂（DAPT）对正常人脐静脉内皮细胞系增殖凋亡的影响。方法分别用不同浓度DAPT（15、30、45、60μM/L）处理体外培养的人脐静脉内皮细胞（HUVECs）12h、24h和48h,MTT法测定内皮细胞活力;粘附实验测定处理24h后细胞粘附率;TUNEL法检测处理24h后细胞凋亡率;Western法检测Notch信号通路受体Notch1的表达。结果 MTT检测显示DAPT显著抑制HUVECs存活（P〈0.01）,并呈浓度时间依赖性;粘附实验结果显示DAPT（24h）可以显著减弱HUVECs粘附能力（P〈0.01）;TUNEL检测显示DAPT（24h）可以显著增加HUVECs凋亡率（P〈0.01）;Westernblot结果显示DAPT使HUVECs中Notch1表达显著下降（P〈0.01）。结论 DAPT可阻断Notch信号通路,抑制正常人脐静脉内皮细胞的增殖,促进细胞凋亡。

Effects of DAPT Treatment on the Proliferation and Apoptosis of Normal Human Umbilical Vein Endothelial Cell Line

Objective To investigate the effects of γ-secretase inhibitor （DAPT）, a specific blocker of the Notch signaling pathway, on the proliferation and apoptosis of normal human umbilical vein endothelial cell line （HUVECs）. Methods The HUVECs were divided into 5 groups： control group and DAPT （15, 30, 45 and 60 μM/L） groups, and each group was treated for 12, 24 and 48 h. MTT method was used to detect the survival rate of the cells; adhesion assay was used to determine the adhesive rate of the cells; TUNEL was used to detect the apoptosis rate of the cells; Western blot was used to detect the expression of Notch1 protein. Results The MTT results showed that DAPT could inhibit the vitality of HUVECs in the dose- and time-dependent manners （P 0.01）; the effect of 60 μM/L DAPT （24 h） was the most obvious. The adhesion experiment results showed that DAPT （24 h） significantly weakened the adhesive capacity of HUVECs on dose-depend manner （P 0.01）. The TUNEL results showed that DAPT （24 h） significantly increased the apoptosis rate of HUVECs in the dose-dependent manner （P 0.01）. Western blot showed that the expression of Notch1 decreased significantly after being treated with DAPT （P 0.01）. Conclusion γ-secretase inhibitor （DAPT） can not only interrupt the transduction of Notch signaling pathway in neonatal rat cardiomyocytes, but also inhibit the viability of the cells and increase their apoptosis.