目的 探讨马兜铃酸(AA)诱导人肾小管上皮细胞株(HK-2)凋亡的可能机制.方法 (1)应用乳酸脱氢酶(LDH)释放试验检测AA的细胞毒作用.(2)应用Hoechst 33258荧光染色检测细胞凋亡指数(AI).(3)应用RT-PCR观察细胞p53 mRNA表达.(4)应用分光光度法检测细胞天冬氨酸特异性半胱氨酸蛋白酶-3(Caspase-3)活性.结果 (1)80,160μg/ml浓度AA刺激细胞48h后,LDH释放率显著性增高(P<0.01).(2)20、40μg/mL浓度AA刺激细胞48h后,可明显抑制细胞生长并诱导其凋亡.(3)AA诱导细胞凋亡时,p53 mRNA表达无明显变化(P>0.05).(4)AA诱导细胞凋亡时,Caspase-3酶活性显著升高(P<0.01).结论 体外条件下,AA可明显抑制HK-2细胞生长并诱导其凋亡;AA诱导HK-2凋亡途径可能是非p53依赖途径;凋亡过程中存Caspase-3酶的激活.
Objectives To investigate the pathogenesis aristolochic acid in inducing apoptosis of cultured renal tubular epithelial cell line HK -2 cell.Methods ( 1 ) HK -2 were stimulated with AA for48h,lactic acid dehydrogenase(LDH) was examined by automatic biochemistry analyzer.(2) Cellular apoptosis were observed under fluorescence microscope after cells were fluorochrome stain by Hoechst 33258,and then apoptotic index (AI) was calculated.(3) The expression of wild - type p53 mRN A were measured by RT - PCR.(4) Caspase -3 activity assay was performed by spectrophotometric method.Results ( 1 ) The LDH release rate is significance increased after stimulated with AA at the concentrations of 80 and 160μg/ml( P <0.01 ).(2) AA( with the concentrations of 20,40μg/ml ) could inhibit HK- 2 cells growth and induce cell apoptosis.(3) The expressions of wild -type p53 mRNA in HK -2 cells after 48h of AA treatment was nearly similar to that in the control goup( P >0.05).(4)The activity of Caspase -3 markedly increased compare with the normal control after 48h of AA treatment( P <0.01 ).Conclusions In this study,we demonstrate that AA is cytotoxic to renal tubular epithelial cells by inhibit renal tubular epithelial cells growth and induce apoptosis.Our results demonstrated that AA - induces apoptosis perhaps do not through p53 - independent pathway in renal tubular epithelial cells.Activation of Caspases - 3 occurs in AA - induced apoptosis pathway.