FIGURE 4.

GSK3β-Nrf2 signaling pathway is involved in H₂O₂-induced apoptosis and ROS generation in MC3T3-E1 cells. MC3T3-E1 cells were treated with or without H₂O₂ in the basic medium for 6 h. TDZD-8 or tBHQ were added 1 h before H₂O₂. (A) Cell viability determined by MTT reduction in MC3T3-E1 cells with (+) or without (–) TDZD-8 treatment in the presence or absence of H₂O₂ (+). (B) Cell viability determined by MTT reduction in MC3T3-E1 cells with (+) or without (–) tBHQ treatment in the presence or absence of H₂O₂ (+). (C,D) The cells were immunostained for TUNEL (green). DAPI staining was used to mark the position of the nuclei. Scale bars = 100 μm. (E,F) The cells were harvested and stained with DCFH-DA (red). Scale bars = 100 μm. Data are presented as the mean ± SD from at least three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001, versus C group; NS, non-significantly different from C group. ^#p < 0.05, ^##p < 0.01, ^###p < 0.001, versus the H₂O₂ group; ns, non-significantly different from H₂O₂ group.