热打击对培养人脐静脉内皮细胞增殖能力的影响

Effects of heat stress on the proliferative ability of human umbilical vein endothelial cells in vitro

目的:研究梯度热打击对体外培养人脐静脉内皮细胞(HUVEC)增殖的影响。方法:设置培养HUVEC细胞的温度梯度(39、41、43℃)进行热打击1 h,相差显微镜观察细胞形态学改变,CCK-8比较细胞增殖率,流式细胞术研究细胞周期改变。结果:与正常对照组比较,1 h热打击结束时,各热打击组均出现部分细胞形态变圆,伪足变短,细胞间隙增大,以43℃组为明显。随热打击程度加深,未伸展细胞占培养细胞百分比增加(P<0.05)。细胞增殖实验显示,与正常对照组比较,热打击后24 h,41℃和43℃组增殖率显著下降(P<0.01),48 h时仅43℃组增殖率显著下降(P<0.05),至72 h,各热打击组与正常对照组无显著差异。流式细胞术检查显示,1 h热打击结束即刻,与正常对照组比较,各热打击组细胞呈现显著的G0/G1期阻滞,以43℃组最显著(P<0.05);至48 h时各热打击组细胞周期基本恢复正常。结论:热打击对HUVEC具有细胞毒效应,可抑制HUVEC的增殖,造成细胞周期G0/G1期阻滞。

Objective：To investigate the effect of gradient heat stress on the proliferative ability of human umbilical vein endothelial cells （HUVECs） in vitro. Methods： HUVECs were exposed to different degrees of temperature in vitro. After thermal exposure for 1 hour,phase contrast microscope was used to observe the morphological changes in HUVECs, and cell counting kit-8 （CCK-8） assay was used to investigate difference of cellular proliferation rate after 72 hours among groups. Flow cytometry was used to investigate the influence of heat stress on HUVECs cell cycle progression. Results： Comparied to the normal control group, cells of each heat stress group became round, pseudopod became shorter, cell space increased, especially in 43 ~C group cells. The ratio of unrounded cells were increased with the increased of heat stress severity （P〈0.05）. Proliferation assay indicated that the proliferation rate of each beat stress groups was significantly decreased in comparison with normal control group 24 hours after heat stress （P〈0.05）. After 48-hour recovery, decrease in proliferation rate was observed only in 43 ℃group （P〈0. 05）, and no difference in the rate of proliferation could be observed 72 hours after recovery. Applying flow cytometry, the arrest of cell cycle G0/G1 phase were observed in heat stress groups, especially in 43 ~C group （P^0.05）. This phe- nomenon disappeared after 48 hours of recovery. Conclusions： Heat stress has cytotoxic effect on HUVECs, and can inhibit its proliferative ability by causing cell cycle G0/G1 phase arrest. Further investigation of the effect of heat stress on vascular endothelial cell may help to understand the mechanism of the pathogenesis of heatstroke.