(A) Representative IHC images of the costaining of PRDM16 and PGC-1α in serial renal biopsy sections from patients with CKD. Scale bar: 20 μm. The black arrow indicates positive costaining tubules; (B) Correlation between the quantification of the positively stained area of PRDM16 and PGC-1α (n = 15); (C–F) HK-2 cells were transfected with PRDM16 siRNA or scrambled siRNA for 24 hours. Representative Western blotting (C) (n = 3) and quantification of PRDM16 (D), PGC-1α (E), and PPAR-γ (F); (G and H) Representative Western blotting (n = 3) and quantification of PGC-1α in stably transfected HK-2 cells after TGF-β treatment for 24 hours; (I) Relative mRNA level of PPARGC1A in stably transfected HK-2 cells after TGF-β treatment for 24 hours. (n = 3); (J–L) Stably transfected HK-2 cells were subjected to hypoxia for 24 hours and reperfusion for 2 hours. Representative Western blotting (J) (n = 3) and quantification of PGC-1α (K) and PPAR-γ (L); (M–O) HK-2 cells were provided with TGF-β, PRDM16 siRNA (PR-siRNA), Scramble, or ZLN005 for 24 hours according to the group assignment. Representative Western blotting (M) and quantification of PGC-1α (N) and fibronectin (O) were shown. Data are mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001; ^†P < 0.05, ^††P < 0.01, ^†††P < 0.001. Asterisks indicate comparison to sham or control group. Crosses indicate comparison to TGF-β or UUO/UIRI/FA groups. Spearman’s correlations (B). Two-tailed Student’s unpaired t test analysis (D–F), One-way ANOVA followed by Tukey’s post test (H, I, K, L, N, and O).