NADH dehydrogenase subunits are overexpressed in cells exposed repeatedly to H2O2

Cells conditioned by repeated treatments with low doses of H2O2, were compared with its parental V79 cells for expression of ND1 and ND4 subunits of NADH dehydrogenase, a mitochondrial gene. It was found that ND1 and ND4 subunits were overexpressed in these conditioned cells. These cells were also found to be resistant to killing upon γ-irradiation through suppression of apoptotic cell death. On irradiation, the expression of both subunits decreased in both cell types, but overall there was more expression of both subunits in the conditioned cells. These findings indicate alteration in the expression of NADH dehydrogenase, a mitochondrial gene, could be involved in the recovery of γ-irradiated cells through inhibition of apoptosis.