Fig. 4

Effect of MKRN1 deficiency on hepatic AMPK signalling and diet-induced NAFLD. Livers from male WT and MK1^−/− mice fed a chow diet or an HFD for 16 weeks were analysed. a Representative livers from mice on an HFD (upper left; fatty livers of HFD-fed WT mice) or a chow diet (upper right; normal livers of chow-fed WT mice). Scale bar = 1 cm. b H&E staining of livers. Scale bar = left, 250 µm; middle, 100 µm; and right, 25 µm. c Liver weights (n = 9 HFD-fed mice, n = 6 chow-fed mice per group). d Representative images of Oil Red O-stained livers (n = 6 mice per group). Scale bar = 100 and 25 µm. e Liver TG contents (WT n = 6 and MK1^−/− n = 7). f Representative images of immunohistochemical staining for macrophage antigens (F4/80) in liver sections. Scale bar = 100 µm. g Hepatic AMPK signalling in WT or MK1^−/− mice. h Relative mRNA levels of genes related to hepatic lipogenesis (WT n = 5 and MK1^−/− n = 6). i ALT and AST serum levels (WT n = 7 and MK1^−/− n = 8). j Schedule of AMPKα2 knockdown. WT and MKRN1-null mice were injected with Ad_US (as control) or Ad_shα2 (shRNA targeting AMPKα2) via the tail vein. k–m Hepatic steatosis induced by MKRN1 deficiency was rescued by the ablation of AMPKα2 using adenovirus. k Representative image of H&E staining. Scale bar = up, 50 µm; middle, 100 µm; and bottom, 500 µm. l Plasma TG contents were measured. m Lipogenic enzymes were analysed by quantitative real-time PCR in livers from WT and MK1^−/− mice infected with adenoviruses. The data in c, e, h, i, l and m are presented as the mean ± s.d. Two-tailed Student’s t-test; ^*P ≤ 0.05, ^**P ≤ 0.01, ^***P ≤ 0.001, n.s. not significant