Figure 3.

Hydrogen peroxide-induced cell death: apoptotic and energetic parameters. A–C) Concentration-dependent cell death (A), NAD⁺ consumption (B), and ATP consumption (C) induced by hydrogen peroxide in control, shPARP1 and shPARG cells. Hydrogen peroxide caused significant cell death (as determined by MTT reduction) and a significant drop in cellular levels of NAD⁺ and ATP at 24 h in control cells. Cell death and loss of cellular NAD⁺ and ATP was significantly prevented by gene silencing of PARP1 and PARG as compared to control. D) Hydrogen peroxide-induced cytotoxicity was prevented by TCA-cycle substrates methyl pyruvate and α-ketoglutarate. Data represent means ± se of 4 independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001.