Figure 4. Nrf2 knockdown compromises the protective effects of Kin in TBHP-treated NPCs. (A, B) Transfection efficiency of lentivirus for Nrf2 knockdown was detected by western blotting. (C) The mitochondria-derived ROS in treated NPCs was detected by MitoSOX staining, and the red fluorescence intensity was quantified; scale bar: 20 μm. (D) The mitochondrial membrane potential in treated NPCs were analyzed by flow cytometry using JC-1 staining. (E) The representative images of SA-β-gal staining of NPCs and quantification of positive cells; scale bar: 200 μm. (F) The apoptosis of NPCs in each treatment group was measured by the TUNEL assay and TUNEL positive cells were quantified; scale bar: 50 μm. (G) The western blotting and quantitative protein levels of p16 and C-caspase3 in the NPCs as treated above. All data are expressed as mean ± SD of at least three independent experiments.