Figure 4.

Proliferator-activated receptor-γ coactivator 1α (PGC1α) regulates the antioxidant activity of Nrf2 through glycogen synthase kinase 3β (GSK3β) after proteasome inhibition in SKOV3 cells. (a) SKOV3 cells were treated with Epox for 12 h. The colocalization of Nrf2 and PGC1α in the nucleus was determined via staining and observed via fluorescence microscopy (magnification, ×400). Western blotting was used to measure the expression of PGC1α after transfection with Scr-shRNA or PGC1α-shRNA plasmids (b) or treatment with 20 μM ZLN005 for 12 or 24 h (d). Data are presented as the mean ± SD, n = 3, ^∗∗P < 0.01 compared with the respective controls. (c) After transfection with Scr-shRNA or PGC1α-shRNA plasmids, SKOV3 cells were treated with 100 nM Epox for 12 h. RT-qPCR was used to detect the expression of NFE2l2, GCLC, HMOX-1, and G6PDH mRNA. Data are presented as the mean ± SD, n = 3, ^∗∗P < 0.01. (e) SKOV3 cells were treated with 20 μM ZLN005 for 24 h or transfected with PGC1α shRNA plasmids. Western blot analysis of the expression of p-GSK3β and GSK3β. Data are presented as the mean ± SD, n = 3, ^∗P < 0.05, ^∗∗P < 0.01 compared with the control. (f) After transfection with Scr-shRNA or PGC1α-shRNA plasmids, cells were treated with Epox (100 nM, 12 h) with or without CHIR99021 (5 μM, 36 h). Relative NFE2l2, GCLC, HMOX-1, and G6PDH mRNA expression was measured by RT-qPCR. Data are presented as the mean ± SD, n = 3, ^∗P < 0.05, ^∗∗P < 0.01.