Molecular mechanism for the influence of gender dimorphism on alcoholic liver injury in mice

It is known that women develop alcoholic liver injury more rapidly and have a lower alcohol toxic threshold than men. However, the detailed molecular mechanisms remain unclear. The precise mechanism responsible for the sex difference needs to be determined. Female and male mice were given ethanol by intragastric infusion every day for 4 weeks. The pathological changes were detected by hematoxylin-eosin, Sirius red, oil red O, periodic acid-Schiff, and Hochest33258 staining in the liver of female and male mice. The related gene and protein expression of hepatocytes stress, proliferation and apoptosis, glycogen synthesis, lipid metabolism, and hepatic fibrosis were also systematically analyzed in the female and male mice. Livers from ethanol-treated female mice had more serious hepatocyte necrosis, liver fibrosis ( P < 0.01), substantial micro/macrovesicular steatosis ( p < 0.01), glycogen consumption ( p < 0.05), and hepatocytes apoptosis ( p < 0.05) than ethanol-treated male mice. The expression of heat shock protein 27 (HSP27), HSP70, proliferating cell nuclear antigen, B-cell lymphoma/leukemia-2 (Bcl-2), and phosphorylated signal transducer and activators of transcription 3 (p-STAT3) was higher in ethanol-treated male mice than ethanol-treated female mice ( P < 0.05 or P < 0.01). But, the expression of Bax (Bcl-2-associated X protein), Caspase 3, CYP2E1 (cytochrome P4502E1), and transforming growth factor βl had the contrary results. Our study suggested that ethanol treatment induced more expression of HSP27 and HSP70, faster hepatocyte proliferation, higher level of glycogen, and interleukin-6 signaling pathway activation, but less hepatocyte apoptosis and CYP2E1 expression in male mice than female mice, which could be helpful to understand the molecular mechanism for the influence of sex difference on alcoholic liver injury.