Figure 4. NF-κB activation protects cells from oxidative-stress-induced death.

(A) HeLa cells were transfected with reporter constructs, and, 8 h after transfection, were stimulated with H₂O₂ (500 nM, 16 h). Reporter gene assays were performed to measure inducible NF-κB transcriptional activity (NF-κB–luc reporter plasmid, closed bars) or general transcriptional activity (β-gal reporter plasmid, open bars). Results are means±S.D. RLU, relative light units. (B) HeLa cells were transfected with vector control or super-dominant IκBα (IκBα SD). After 48 h, cells were treated with H₂O₂ (16 h) as indicated, and living cells were determined by Crystal Violet staining. Results are means±S.D. Inset, lysates of control and IκBα-transfected cells were analysed for IκBα expression by immunoblotting with anti-IκBα.