Protective effect of N-acetyl-L-cysteine on the cytotoxicity induced by iohexol in HK-2 cells / 中华肾脏病杂志

ABSTRACT

Objective To explore the protective effect and mechanism of antioxidant N-acetyl-L-cysteine (NAC)on the cytotoxicity induced by iohexol in HK-2 cells. Methods The incubated HK-2 cells were divided into four groupscontrol group,iohexol group,NAC group,and NAC+iohexol group(pre-incubated with NAC and then co-incubated with iohexol).The cell viability was tested by CCK-8 assay;cell apoptosis was determined by Hoechst 33342 fluorescence staining and flow cytometry with Annexin V-FITC/PI double staining.Intracelluar ROS waft detected by flow cytometry with DCFH-DA fluorescence staining.The signaling transduction pathways were investigated by Western blotting and immunofluorescence staining. Results Iohexol decreased cell viability,and increased apoptosis in a dose-and time-dependent manner.In iohexol(100 gl/L,6 h)group,ROS was increased by 1.30-fold of control(P＜0.05).In NAC(5,10,15 mmol/L)+iohexol groups,the cell viability was increased by 104%,118%,130%respectively,and iohexol group was 63% (P＜0.05, respectively); apoptosis rate was decreased by 13.51%, 13.46%, 12.23% respectively, and iohexol group was 24.41% (P＜0.05, respectively); ROS was decreased by 1.05-fold, 0.93-fold, 0.86-fold respectively, and iohexol group was 1.3-fold (P＜0.05, respectively).Iohexol induced the increase of p53 phosphorylatian and activity, then up-regulation of Bax and down-regulation of Bcl-2 protein expression. Iohexol induced the release of cytochrome C from mitochondria to cytoplasm, all of which caused final activation of caspase-3. The expression levels of p53, Bax and caspase-3 were decreased, while Bcl-2 protein expression level was increased by NAC. Conclusions Iohexol induces the increase of apeptosis rate and ROS generation in HK-2 cells. NAC attenuates this iohexol-induced cytotoxicity by decreasing intracelluar ROS, which is mairdy through the intrinsic pathway.