Figure 3.

PKCβ activity is required for H₂O₂-induced apoptosis and NF-κB activation. A, IκB and p66^shc phosphorylation determined by Western blot in UAMS-32 cells pretreated without or with 0.5 mm LY333531 (LY) for 1 h, followed by 100 μm H₂O₂ or 100 μm PMA for 6 h. B, Caspase 3 activity in cells described in panel A, cultured in the presence of vehicle (veh) or 100 μm H₂O₂ for 6 h. C, Luciferase activity in cells transfected with the NF-κB-luc reporter construct after pretreatment with 10 μm hispidin or LY333531 followed by H₂O₂ or PMA, as above, for 24 h. D, Caspase 3 and luciferase activity in empty vector (EV) or p66^shc-silenced UAMS-32 cells, as in panels B and C, treated with veh or 10 μm PMA. Bars indicate means ± sd of triplicate determinations. *, P < 0.05 vs. veh; †, P < 0.05 vs. equivalent treatment in veh-treated or EV-silenced cells.