Division of Metabolism and Pediatric Endocrinology, Departments of Medicine, Pediatrics, Biological Chemistry and Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
School of Medicine, Ponce Health Sciences University, Ponce, PR, USA.
Sci Rep. 2017 May 10;7(1):1661. doi: 10.1038/s41598-017-01937-4.
Impaired estrogens action is associated with features of the metabolic syndrome in animal models and humans. We sought to determine whether disruption of hepatic estrogens action in adult male mice could recapitulate aspects of the metabolic syndrome to understand the mechanistic basis for the phenotype. We found 17β-estradiol (E) inhibited hepatic gluconeogenic genes such as phosphoenolpyruvate carboxykinase 1 (Pck-1) and glucose 6-phosphatase (G6Pase) and this effect was absent in mice lacking liver estrogen receptor α (Esr1) (LERKO mice). Male LERKO mice displayed elevated hepatic gluconeogenic activity and fasting hyperglycemia. We also observed increased liver lipid deposits and triglyceride levels in male LERKO mice, resulting from increased hepatic lipogenesis as reflected by increased mRNA levels of fatty acid synthase (Fas) and acetyl-CoA carboxylase (Acc1). ChIP assay demonstrated estradiol (E) induced ESR1 binding to Pck-1, G6Pase, Fas and Acc1 promoters. Metabolic phenotyping demonstrated both basal metabolic rate and feeding were lower for the LERKO mice as compared to Controls. Furthermore, the respiratory exchange rate was significantly lower in LERKO mice than in Controls, suggesting an increase in lipid oxidation. Our data indicate that hepatic E/ESR1 signaling plays a key role in the maintenance of gluconeogenesis and lipid metabolism in males.
雌激素作用受损与动物模型和人类代谢综合征的特征有关。我们试图确定成年雄性小鼠肝脏雌激素作用的破坏是否可以再现代谢综合征的某些方面,从而了解表型的机制基础。我们发现 17β-雌二醇 (E) 抑制了磷酸烯醇丙酮酸羧激酶 1 (Pck-1) 和葡萄糖 6-磷酸酶 (G6Pase) 等肝糖异生基因,而缺乏肝雌激素受体 α (Esr1) (LERKO 小鼠) 的小鼠则没有这种作用。雄性 LERKO 小鼠表现出肝糖异生活性升高和空腹高血糖。我们还观察到雄性 LERKO 小鼠肝脏脂质沉积和甘油三酯水平增加,这是由于肝脂肪生成增加所致,反映在脂肪酸合酶 (Fas) 和乙酰辅酶 A 羧化酶 (Acc1) 的 mRNA 水平升高。ChIP 分析表明,雌二醇 (E) 诱导 ESR1 与 Pck-1、G6Pase、Fas 和 Acc1 启动子结合。代谢表型分析表明,与对照组相比,LERKO 小鼠的基础代谢率和摄食量均较低。此外,LERKO 小鼠的呼吸交换率明显低于对照组,表明脂质氧化增加。我们的数据表明,肝脏 E/ESR1 信号在维持男性的糖异生和脂质代谢中起着关键作用。