镉致HEK293细胞氧化损伤及细胞凋亡

Oxidative damage and apoptosis induced by cadmium exposure in HEK293 cells

[目的]探讨镉致人胚胎肾HEK293细胞氧化损伤和凋亡的情况。[方法]对HEK293细胞使用0、30、60、120μmol/L浓度的氯化镉(CdCl_2)染毒1、3、6、12 h后,MTT法测定细胞生长情况,流式细胞术检测细胞中活性氧(ROS)含量和细胞凋亡,用硫代巴比妥酸法检测细胞内丙二醛(MDA)含量,用比色法测定谷胱甘肽过氧化物酶(GSH-PX)活力,用水溶性四唑盐法检测细胞中超氧化物歧化酶(SOD)活力。[结果]不同浓度的CdCl_2作用不同时间,细胞贴壁性减弱,细胞变圆,伪足消失。随着CdCl_2浓度的增高,作用时间延长,细胞的生长受到抑制,在CdCl_2浓度为120μmol/L,染毒时间为12 h时达到峰值。随着作用时间的延长,30μmol/L和60μmol/L CdCl_2染毒组细胞凋亡率逐渐增加(P趋势=0.001,P趋势=0.009);当作用时间分别为1、3、6 h,随着CdCl_2浓度的增加,凋亡率逐渐增加(P趋势=0.003或P趋势=0.001)。相同染毒时间,细胞内MDA、ROS含量随着CdCl_2浓度的升高而增高(P趋势<0.001或P趋势=0.001);当CdCl_2浓度分别为30、60、120μmol/L时,随着染毒作用时间的延长,MDA和ROS含量逐渐增高(均P趋势<0.05)。与0μmol/L CdCl_2组比较,30、60、120μmol/L组细胞中SOD和GSH-PX活力均降低(P<0.05),且随着CdCl_2浓度的增加细胞中SOD和GSH-PX活力呈下降趋势(P趋势<0.001);当染毒浓度分别为30、60、120μmol/L时,细胞SOD和GSH-PX活力随着作用时间的延长而降低(均P趋势<0.01)。[结论]镉可导致HEK293细胞氧化损伤和细胞凋亡。

[ Objective ] To test the oxidative damage and apoptosis in human embryonic kidney cells （HEK293 cells） induced by cadmium. [ Methods ] HEK293 cells were euhured with 0, 30, 60, and 120μmol/L cadmium chloride （CdCl2） for 1, 3, 6, and 12h, respectively. Cell growth was tested by MTT assay. The levels of apoptosis and cytosolic reactive oxygen species （ROS） were measured by flow eytometry. Malondialdehyde （MDA） level was detected by thiobarbiturie acid method. Glutathione peroxidase （GSH-PX） activity was determined by colorimetric method. Superoxide dismutase （SOD） activity was measured by water-soluble tetrazolium salt method. [ Results ] Cell adhesion was decreased, cells became round, and pseudopodia disappeared following different concentrations of CdCl2 exposure for different exposure time. With the increasing CdCl2 concentrations and exposure time, the growth of cells was inhibited, and the inhibition reached maximum after treatment with 120 μmol/L CdCI2 for 12 h. The apoptosis rates increased with extending exposure time at 30 μmol/L and 60 μmol/L CdCl2 （Ptrend =0.001, Ptrend=0.009）. With the increasing of CdC12 concentrations, the apoptosis rates increased at exposure time of 1, 3, and 6 h, respectively （Ptrend=0.003 or Ptrend=0.001）. At the same exposure time, the levels of MDA and ROS increased with higher concentrations of CdC12 （Ptrend〈 0.001 or Ptrend=0.001）. The levels of MDA and ROS also increased with exposure time extending at the concentrations of CdC12 of 30, 60, and 120 μmol/L, respectively （Ptrend〈0.05）. Compared with 0 μmol/L C dC12 group, the activities of SOD and GSH-PX decreased （P 〈 0.05） in the groups of 30, 60, and 120 μmol/L CdCl2. The activities of SOD and GSH-PX decreased following with the increasing of CdCl2 concentrations （Prend〈 0.001）. The activities of SOD and GSH-PX decreased with longer exposure time at 30, 60, and 120 μmol/L CdCl2, respectively （Prend〈 0.01）. [ Conclusion ] Cadmium can induce oxidative damage and apoptosis in HEK293 cells.