Fig. 1. Hepatic SIRT6 protein levels are decreased in the patients with alcoholic cirrhosis and hepatic Sirt6 deletion aggravates oxidative stress in an ALD mouse model.

(A) Western blot and quantification analysis of SIRT6 protein in the liver of normal controls and alcoholic cirrhosis (AC) patients (n=3–5/group). (B) Western blot and quantification analysis of Sirt6 in hepatic tissues from WT male mice that were fed with a control diet (Pair-fed) or 5% ethanol (ETOH, vol/vol) diet (ETOH) for 4 weeks. (C-I) Control LoxP and Sirt6 KO male mice were pair-fed or ethanol-fed (6% vol/vol) for 15 days plus a single binge (6 g/kg) on day 16. (C) Serum ALT measurements. (D, E) Hepatic triglycerides (TG) and total cholesterol (TC) measurements. (F) Mouse hepatic staining by H&E, IHC detection of 4-HNE, and fluorescence analysis of ROS by DHE and DCFDA dyes. (G) Hepatic H₂O₂ measurements. (H) Hepatic GSH measurements. (I) Hepatic Mt1 mRNA analysis by qPCR. Data are presented as mean ± S.E.M. Nonparametric Mann-Whitney U tests were used for statistical analysis. In panel B, #p < 0.05 (n = 4–5/group). In panels C-I, #p < 0.05 and ##p < 0.01 for LoxP vs. Sirt6 KO; *p < 0.05 and **p < 0.01 for Pair-fed vs. ETOH for the same genotype (n=4–6/group). Images were captured by light microscopy for H&E and IHC staining (200× magnification), and fluorescence images were obtained using a fluorescence microscope (200× magnification). Scale bars: 50 μm. ALT, alanine transaminase; DCFDA, dichlorofluorescin diacetate; DHE, dihydroethidium; GSH, glutathione; 4-HNE, 4-hydroxynonenal; IHC, immunohistochemistry; qPCR, quantitative PCR; ROS, reactive oxygen species.