Fig. 5. Protective effects of DOX-induced mtUPR on H₂O₂-induced cellular damage of 661w cells.

a, b Western blot analysis of mtUPR-related proteins showed the upregulation of HSP60 and CHOP in H₂O₂-induced cells after 10 μmol/L DOX pretreatment. The relative expression of HSP60 and CHOP were normalized to β-actin and β-Tubulin, respectively (n = 3). c, d 10 μmol/L DOX increased cell viability in 661w cells with or without 600 μmol/L H₂O₂ stimulation with MTT assay (n ≥ 5). e, f The cell survival in the DOX + H₂O₂ group was higher than that of the H₂O₂ group based on Hoechst 33342 staining (n = 6). g, h 10 μmol/L DOX increased the expression of Bcl-2 in 600 μmol/L H₂O₂-treated 661w cells by western blotting. The relative expression of Bcl-2 was normalized to β-actin (n = 3). i, j Representative images of ROS and analysis of fluorescence intensity (n = 5). k Attenuation of 600 μmol/L H₂O₂-induced decrease of mitochondrial membrane potential after 10 μmol/L DOX pretreatment (n = 4). l, m Improvement of 600 μmol/L H₂O₂-induced reduction of mitochondrial mass after 10 μmol/L DOX pretreatment (n = 6). Data are shown as mean. Scale bar: 100 μm.