FIG. 4.

H₂O₂-induced cell death is independent of TNFR1 and de novo protein synthesis. (A) H₂O₂-induced cell death does not require de novo protein synthesis. The wt MEF cells were first pretreated with CHX (10 μg/ml, 30 min), followed by H₂O₂ exposure (500 μM, 12 h). The effectiveness of CHX treatment was confirmed by the decrease of the c-myc protein level in wt MEF cells detected by Western blotting (lower panel). (B) H₂O₂-induced cell death does not involve TNFR1. wt MEF cells and TNFR1^−/− primary fibroblasts were treated with H₂O₂ (500 μM, 12 h) or TNF-α (25 ng/ml plus CHX at 10 μg/ml, 12 h). Cell death was quantified by the determination of LDH leakage. Data are presented as means ± standard deviations from at least three independent experiments.