Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America.
PLoS One. 2011;6(12):e29463. doi: 10.1371/journal.pone.0029463. Epub 2011 Dec 20.
Alcoholic liver disease (ALD) affects millions of people worldwide and is a major cause of morbidity and mortality. However, fewer than 10% of heavy drinkers progress to later stages of injury, suggesting other factors in ALD development, including environmental exposures and genetics. Females display greater susceptibility to the early damaging effects of ethanol. Estrogen (E2) and ethanol metabolizing enzymes (cytochrome P450, CYP450) are implicated in sex differences of ALD. Sex steroid hormones are developmentally regulated by the hypothalamic-pituitary-gonadal (HPG) axis, which controls sex-specific cycling of gonadal steroid production and expression of hepatic enzymes. The aim of this study was to determine if early postnatal inhibition of adult cyclic E2 alters ethanol metabolizing enzyme expression contributing to the development of ALD in adulthood. An androgenized rat model was used to inhibit cyclic E2 production. Control females (Ctrl), androgenized females (Andro) and Andro females with E2 implants were administered either an ethanol or isocalorically-matched control Lieber-DeCarli diet for four weeks and liver injury and CYP450 expression assessed. Androgenization exacerbated the deleterious effects of ethanol demonstrated by increased steatosis, lipid peroxidation, profibrotic gene expression and decreased antioxidant defenses compared to Ctrl. Additionally, CYP2E1 expression was down-regulated in Andro animals on both diets. No change was observed in CYP1A2 protein expression. Further, continuous exogenous administration of E2 to Andro in adulthood attenuated these effects, suggesting that E2 has protective effects in the androgenized animal. Therefore, early postnatal inhibition of cyclic E2 modulates development and progression of ALD in adulthood.
酒精性肝病(ALD)影响着全球数以百万计的人,是发病率和死亡率的主要原因。然而,只有不到 10%的重度饮酒者会发展到损伤的后期阶段,这表明 ALD 发展的其他因素,包括环境暴露和遗传因素。女性对乙醇的早期损伤作用更敏感。雌激素(E2)和乙醇代谢酶(细胞色素 P450,CYP450)与 ALD 的性别差异有关。性甾体激素受下丘脑-垂体-性腺(HPG)轴的发育调控,该轴控制着性腺类固醇产生的性别特异性循环和肝酶的表达。本研究旨在确定产后早期抑制成年周期性 E2 是否会改变乙醇代谢酶的表达,从而导致成年期 ALD 的发展。雄激素化大鼠模型用于抑制周期性 E2 的产生。对照雌性(Ctrl)、雄激素化雌性(Andro)和接受 E2 植入的 Andro 雌性接受乙醇或等热量对照 Lieber-DeCarli 饮食治疗 4 周,评估肝损伤和 CYP450 表达。与 Ctrl 相比,雄激素化加重了乙醇的有害影响,表现为脂肪变性、脂质过氧化、促纤维化基因表达增加和抗氧化防御能力降低。此外,两种饮食中 CYP2E1 的表达在 Andro 动物中均下调。CYP1A2 蛋白表达没有变化。此外,成年期连续给予外源性 E2 可减弱这些作用,表明 E2 在雄激素化动物中具有保护作用。因此,产后早期抑制周期性 E2 可调节成年期 ALD 的发展和进展。