H2O2 decreases Klotho expression in mouse renal tubular epithelial cells

Abstract

Objective To evaluate the effect of oxidative injury induced by peroxide oxidase on Klotho expression in mouse renal tubular epithelial cells (TCMK-1) and to explore the possible pathway. Methods TCMK-1 cells were exposed to H2O2 of different concentrations. Reactive oxygen species (ROS) was examined by flow cytometry. Cell viability was assessed by CCK-8. Cell apoptosis was evaluated by flow cytometry and Hoechst 33258 staining. The expression of Klotho, apoptosis-associated proteins and anti-oxidant enzymes were determined by Western blotting. Results Compared with control group, after H2O2 stimulating TCMK-1 cell, ROS was dramatically elevated (allP <0.05) and the expression of anti-oxidant enzymes, SOD2 and CAT went down (all P <0.05); the expression of Klotho was inhibited (all P <0.05); cell viability of TCMK-1 cells was decreased (all P <0.05) in a dose-dependent manner (0.3 to 0.9 mmol/L); cell apoptosis was significantly increased in TCMK-1 cells following the concentration of H2O2 (allP <0.05); Bax/Bcl-2 and the phosphororation of JNK and p38 were obviously elevated in TCMK-1 by H2O2 induction (all P <0.05). Conclusion Oxidative injuries induced by H2O2 significantly suppresses the expression of Klotho in TCMK-1 cells. And cell apoptosis was increased, p38 and JNK pathway was activated. Key words: Oxidative stress; Apoptosis; Mitogen-activated protein kinase; Klotho