硫酸镉诱导人胚胎肝细胞热应激蛋白70表达及氧化应激的研究

Expression and anti-oxidant effect of heat shock protein 70 induced by cadmium sulfate in L-02 cell line

目的研究硫酸镉诱导人胚胎肝(L-02)细胞热应激蛋白70(heat shock protein 70,HSP70)表达及氧化应激作用,以探讨HSP70表达与细胞抗氧化作用的关系。方法将对数生长期的L-02细胞分别暴露于终浓度为0(对照,双蒸水)、1、2、4、8、16、32、64、128μmol/L的硫酸镉溶液培养24h,采用MTT法测定细胞活性。将对数生长期的L-02细胞分别暴露于含终浓度为0(对照,双蒸水)、1、2、4μmol/L硫酸镉的培养基中,培养24h后,检测细胞裂解液中谷胱甘肽过氧化物酶(GSH-Px)活力、超氧化物歧化酶(SOD)的活力和丙二醛(MDA)的含量以及细胞HSP70的表达。结果与对照组比较,2~128μmol/L硫酸镉染毒组L-02细胞的存活率降低,差异有统计学意义(P<0.05);且随着硫酸镉染毒浓度的升高,L-02细胞的存活率呈下降趋势明显。与对照组比较,4μmol/L硫酸镉染毒组L-02细胞SOD、GSH-Px活力均上升,差异有统计学意义(P<0.05);而各浓度硫酸镉染毒组L-02细胞内MDA的含量均无明显变化。随着硫酸镉染毒浓度的升高,L-02细胞内HSP70蛋白的阳性表达呈上升趋势。结论在本研究剂量下,硫酸镉可诱导L-02细胞株HSP70表达上调,引起细胞抗氧化活性增强。

Objective To understand the expression of heat stress protein 70 (HSP70) and oxidative stress in human embryonic liver (L -02) cells exposed to cadmium sulfate,and to explore the relationship between HSP70 expression and cellular antioxidant activity.Methods L -02 cells in logarithmic growth phase were exposed to cadmium sulfate solution with the concentration of 0 (control,double distilled water),1,2,4,8,16,32,64 and 128 μmol/L respectively for 24 h,then the cell viability was determined by MTT assay.And then the L-02 cells in the logarithmic growth phase were exposed to cadmium sulfate with the concentration of 0 (control,double distilled water),1,2 and 4 μmol/L respectively for 24 h,after treatment,the activity of glycopeptide peroxidase (GSH-Px),superoxide dismutase (SOD),the content of malondialdehyde (MDA) and the expression of HSP70 in the cell lysate were detected.Results Compared with the control group,the survival rate of L-02 cells in the 2 -128 μmol/L cadmium sulfate exposure groups was significantly lower (P <0.05) with a dose dependent manner. Compared with the control group,the activities of SOD and GSH-Px in L-02 cells in 4 μmol/L cadmium sulfate exposure group significantly increased (P<0.05).There was no significant change was seen in the content of MDA in L-02 cells of each cadmium sulfate exposure group;With the increase of cadmium sulfate concentration,the positive expression of HSP70 protein in L-02 cells increased.Conclusion At the dose (4 μmol/L) in the present study,cadmium sulfate can increase HSP70 expression in the L-02 cell line and enhance antioxidant activity of the cells.