Hormonal control of NASH development and progression

摘要/概要 非酒精性脂肪性肝病（NAFLD）包括一系列病理，从单纯性脂肪变性到 非酒精性脂肪性肝炎（NASH -脂肪变性、肝细胞气球样变和炎症，伴或不伴 纤维化）。NASH在肥胖和糖尿病患者中高度流行，是心血管疾病的独立危险因素。 疾病，肝硬化和肝细胞癌，这些毁灭性的疾病在退伍军人中比 在一般人群中。育龄妇女NASH的发病率较低;然而，这种保护作用已经丧失。 绝经后NASH发生率等于或超过男性。临床和实验数据都表明 雌激素在保护女性抵抗NASH方面起着重要作用。此外，雌激素的保护作用 也可以通过雄激素到雌激素的组织依赖性芳构化而扩展到男性。尽管有这些知识， 雌激素介导的保护作用的精确的组织特异性机制尚未被直接研究。 这项建议将集中在雌激素和生长激素（GH）之间的相互关系，特别是在 肝细胞水平，其中已发表的文献和我们小组生成的初步数据导致 假设需要雌激素受体ER β和GH受体（GHR）来减缓NASH 部分通过维持肝细胞Stat 5 b活性来促进发育。研究将比较雄性和雌性小鼠， 成年发病、肝细胞特异性、雌激素受体、ER β或GHR单独或组合敲减，以： SA 1确定ER β在肝细胞Stat 5 b作用中的作用及其对肝功能和生理的影响， GHR介导的信号传导的存在和不存在; SA 2确定肝细胞ER β是否保护免于饮食- 在存在和不存在GHR的情况下诱导NASH; SA 3确定肝细胞ER β和/或GHR是否发挥作用 在他莫昔芬（TAM）诱导的NASH进展中。终点分析包括评估1）GH轴功能， 全身代谢、肝脏脂质含量和病理学，2）对急性GH激发的肝脏反应（西方 下游细胞内信号的印迹分析和3）使用单克隆抗体的肝细胞类型特异性基因表达 核RNA-Seq（snRNA-Seq），一种提供潜在串扰重要信息的技术 在肝脏内的细胞类型之间，对NASH的发展至关重要。该项目的成果将产生 确定未来药物靶点以预防男性和女性NASH进展的新机制见解 老兵

Abstract/Summary Non-alcoholic fatty liver disease (NAFLD) includes a spectrum of pathologies ranging from simple steatosis to non-alcoholic steatohepatitis (NASH – steatosis, hepatocyte ballooning and inflammation, with or without fibrosis). Highly prevalent in obese and diabetic patients, NASH is an independent risk factor for cardiovascular disease, cirrhosis, and hepatocellular carcinoma, devastating diseases that are more prevalent in veterans than in the general population. Women of reproductive age have lower rates of NASH; however, this protection is lost after menopause when NASH rates equal or exceed those for men. Both clinical and experimental data indicate that estrogen plays a major role in protecting women against NASH. Moreover, the protective effects of estrogen may also extend to men via tissue-dependent aromatization of androgens to estrogens. Despite this knowledge, the precise tissue-specific mechanisms for estrogen-mediated protection have not been directly investigated. This proposal will focus on the interrelationship between estrogen and growth hormone (GH), specifically at the level of the hepatocyte, where published literature and preliminary data generated by our group have led to the HYPOTHESIS that the estrogen receptor, ER, as well as the GH receptor (GHR), are required to slow NASH development in part by sustaining hepatocyte Stat5b activity. Studies will compare male and female mice with adult-onset, hepatocyte-specific, knockdown of the estrogen receptor, ER or GHR alone, or in combination to: SA1 Determine the role of ER in hepatocyte Stat5b action and its impact on hepatic function and physiology in the presence and absence of GHR-mediated signaling; SA2 Determine if hepatocyte ER protects against diet- induced NASH, in the presence and absence of GHR; SA3 Determine if hepatocyte ER and/or GHR play a role in tamoxifen (TAM) induced NASH progression. Endpoint analysis includes assessment of 1) GH-axis function, whole body metabolism, liver lipid content and pathology, 2) Hepatic response to acute GH challenge (western blot analysis of downstream intracellular signals and 3) Hepatic cell-type specific gene expression using single nuclei RNA-Seq (snRNA-Seq), a technique that provides important information on the potential crosstalk between cell types within the liver, critical for NASH development. The outcomes of this project will generate new mechanistic insights to identify future drug targets to prevent NASH progression in both male and female veterans.