Knockout of Twist1 gene in renal tubules slowed down renal fibrosis by restoring fatty acid metabolism disorders. A. Western blot analyses showed that Twist1 expression was decreased significantly in the kidneys of PT-Twist1-/- but not WT mice after UUO. B. Electron microscopic images showed lipid droplets (LDs) in the kidneys from the WT and PT-Twist1-/- mice with UUO. Red arrows indicate lipid vacuoles. N indicates nucleus. Bar = 2 µm. C. Triglyceride levels were detected in the kidneys of the WT and PT-Twist1-/- mice with UUO, *P < 0.05. D. The ATP level in the kidneys of the WT and PT-Twist1-/- mice with UUO were detected, *P < 0.05. E and F. Triglyceride and ATP were detected in kidneys of the WT and PT-Twist1-/- mice with UIRI, *P < 0.05. G. The expression of Twist1, PGC-1α, PPARα, CPT1, ACOX1, α-SMA, COL1A1, COL4A1 and FN was detected by immunohistochemical in the UUO-induced kidneys from the WT and PT-Twist1-/- mice (400×). Bar = 50 µm. H and I. Twist1, PGC-1α, PPARα, CPT1 and ACOX1 protein expression in UIRI and UUO kidneys from WT, PT-Twist1+/+ and PT-Twist1-/- mice. J and K. Histogram showing density correction for the loading control (β-actin). Data are presented as the mean ± SEM for each group of mice (n = 6 in the sham group; n = 6 in the UIRI group; n = 6 in the UUO group). *P < 0.05.