Bmi-1基因表达与血管内皮细胞衰老的相关性

Correlation between Bmi-1 Gene Expression and Vascular Endothelial Cells Senescence

目的:探讨Bmi-1基因与人脐静脉内皮细胞(HUVECs)衰老的相关性,为研究血管内皮细胞衰老的分子机制打下基础。方法:采用细胞传代及肿瘤坏死因子α(TNF-α)刺激方法模拟内皮细胞衰老,用SA-β-半乳糖酐酶(SA-β-gal)染色检测衰老,Real-time PCR检测P16INK4A及Bmi-1基因的表达变化。结果:随着细胞传代次数的增加,HUVECs体积变大,细胞浆内颗粒和空泡增多,β-gal阳性染色率显著增多,P16INK4A mRNA表达逐渐升高(第6、8代与第1代相比P<0.05),同时Bmi-1 mRNA表达下降(第2、4、6、8代与第1代相比均P<0.05)。TNF-α(10 ng/mL)孵育HUVECs 48 h,与对照组相比,P16INK4A mRNA表达明显增加(P<0.05),Bmi-1 mRNA表达下降(P<0.05)。结论:Bmi-1在衰老内皮细胞中表达显著降低,提示其在血管内皮细胞衰老发生发展中起重要作用。

Objective To explore the correlation between the expression of Bmi-1 and senescence of human umbilical vein endothelial cells（ HUVECs）,so as to provide basis for further research on molecular mechanism of vascular endothelial cells senescence. Methods HUVECs were isolated from fresh human umbilical vein and cultured in vitro. Cellular senescence was induced by passage or TNF-α（ tumor necrosis factor,TNF） stimulation. The state of HUVECs senescence was identified by SA-β-galactosidase staining. The mRNA expression of P16INK4 A and Bmi-1 was detected by real-time RT-PCR. Results With the increasing passages of HUVECs,the cells size,intracellular particles and vacuoles,and SA-beta-galactosidase staining positive cells numbers were obviously increased. Compared to the first generation,the mRNA expression of p16INK4 A was up-regulated gradually in the sixth and eighth generation（ P〈0. 05）. But the mRNA expression of Bmi-1 was significantly decreased in the second,forth,sixth and eighth generations than that in the first generation（ P〈0. 05）. After cocultured with TNF-α at a concentration of 10 ng /mL,the mRNA expression of P16INK4 A in HUVECs was significantly increased than that in the control group（ P〈0. 05）. Conclusion The expression of Bmi-1 is significantly decreased in aging HUVECs,which may play a critical role in the development of vascular endothelial cells senescence.