Figure 5.

Oxidative stress involved in Akt/ASK1/p38 MAPK pathway in nickel-induced apoptosis. (A) Effects of NAC and catalase on the Akt phosphorylation at Ser473 and ASK1 phosphorylation at Thr838. BEAS-2B cells were pretreated with or without NAC (10 mM) and catalase (2000 units/ml) for 2 h and then coincubated with 2 μg/cm² Ni₃S₂ for 48 h. The protein levels were measured by Western blot assays and were from three separate experiments. Blots were stripped and reprobed with antibody against Akt and ASK1. All conditions are the same as described in Figure 1E. (B) Quantitative analyses of the blots are normalized to Akt and ASK1, respectively. * (P < 0.05) is significantly different between the indicated two groups. (C) Effects of NAC and catalase on p38 phosphorylation. BEAS-2B cells were similarly treated with the agents indicated above, and p38 phosphorylation was determined by Western blotting. Representatives here are from three separate experiments. Blots were stripped and reprobed with antibody against p38. Quantitative analyses of the blots are normalized to p38 and displayed on lower panel. * (P < 0.05) represents a significant difference between the two indicated groups.