Fig. 2. The cytoprotective role of DJ-1 against oxidative stress.

A549 cells were treated with 1 mM H₂O₂ for indicated times. a Viability was estimated using Hoechst 33342 and PI double staining. b Expression of DJ-1 and Cys106-oxidized DJ-1 determined by western blotting. c Relative expression is also shown. d Oxidative stress analyzed by GSSG/GSH ratio. e DJ-1 mRNA expression was determined by RT-PCR. f Representative flow cytometry images using Annexin V and PI double staining in A549 cells and A549 cells with DJ-1 KO. g Quantification is also shown. h A549 cells with DJ-1 KO were transfected with pcDNA3.1, WT DJ-1, or C106A DJ-1 plasmids followed by treatment with 1 mM H₂O₂ for 2 h and analyzed using DCF staining. i Quantification is also shown. N = 3 replicates; *P < 0.05, **P < 0.01; ***P < 0.001. Data are shown as means ± s.e.m.