At this time point, food intake and weight gain were similar between the two genotypes, and KO mice had only modestly greater hepatic steatosis compared with WT mice (Supporting Fig. 7). Under these conditions, plasma-alcohol levels in KO mice were 30-fold higher than WT mice (Fig. 6A). We conclude that KO mice have defective hepatic ethanol metabolism that is independent of the severity of ethanol-induced Idasanutlin purchase liver steatosis. β-Catenin regulates glutamine synthetase expression in the liver,

and KO mice develop hyperammonemia in certain conditions. 20 Consistent with those previous results, we found that in freshly collected blood samples, the KO/ethanol group had significantly higher plasma-ammonia levels, compared with the WT/ethanol group (Fig. 6B). This hyperammonemia likely represents an additional source of morbidity in EtOH KO mice. Given the high blood-alcohol levels in KO mice, we measured the activity of the major enzymes responsible for hepatic ethanol metabolism. Both ADH and ALDH activities were lower in PF KO mice. However, enzyme activities in the two EtOH groups were similar (Fig. 7A). The nicotinamide

adenine dinucleotide (NAD)/NADH ratio was similar between KO and WT mice (Supporting Fig. 8). Because of previous reports that ethanol-metabolizing Ulixertinib mouse enzymes have a perivenous zone-predominant expression pattern and the role of β-catenin as a transcriptional regulator, we then asked whether β-catenin regulated the expression of major genes involved in alcohol metabolism. Real-time PCR analysis showed lower expression of Adh1 and Aldh2 in KO mice (Fig. 7B). Western blotting analysis revealed lower ADH 1 protein levels in both groups of KO mice, but ALDH2 levels were lower only in EtOH KO mice (Fig. 7C,D). Western blotting analysis for Cyp2E1 protein levels in hepatic microsomal

preparations showed increased expression in WT mice on ethanol. However, KO mice had almost selleck compound no detectable levels of Cyp2E1 protein on either diet (Fig. 7E,F). We then analyzed the expression pattern of ADH1 in liver sections by immunofluorescence microscopy (Fig. 8). PF and EtOH WT mice exhibited a modest perivenous-predominant staining pattern for ADH1, and diffuse cytoplasmic ADH1 staining was visible within hepatocytes (Fig. 8, panels A-D and I-L, respectively). In contrast, PF KO mice had less-prominent ADH1 staining around the central veins (Fig. 8, panels E-H). Furthermore, EtOH KO mice had a patchy, nonuniform ADH1 staining, with several hepatocytes showing aberrantly stained globules projecting into intracellular vacuoles (Fig. 8, panels M-P). Taken together, these results establish that β-catenin regulates the expression, subcellular and lobular localization, and activity of the major ethanol-metabolizing enzymes in the liver.