Objective: To explore the effect of hOGG1 gene on the repair capability of oxidative damage in mitochondrial DNA induced by hexavalent chromium (Cr (VI)).
Methods: After incubating with Cr(VI) at the concentrations of 2, 8, 32 micromol/L for 24 hours, mitochondria from L-02 hepatocytes were collected. Cellular ROS and hOGG1 mRNA and mitochondrial 8-OHdG and hOGG1 protein in L-02 hepatocytes were examined by Fluorometric Assay Kit, RT-qPCR, 8-OHdG ELISA Kit and western blot respectively.
Results: Compared with the control group, the levels of cellular ROS and mitochondrial 8-OHdG in 8 and 32 micromol/L Cr(VI) treated groups were significantly increased (P < 0.05). The levels of cellular hOGG1 mRNA and mitochondrial hOGG1 protein in 2 micromol/L Cr (VI) treated group were increased significantly (P < 0.05), but decreased in 32 micromol/l. group (P < 0.05).
Conclusion: Overproduction of cellular ROS could be induced by Cr (VI) and could result in genomic DNA oxidative damage, and the lower expression of cellular hOGG1 gene could decrease the repair capability of mitochondrial DNA. Therefore, the cellular hOGG1 gene exerted important effect in the repair of mitochondrial DNA oxidative damage induced by Cr( VI).