Uncovering the Role of Retinoic Acid Receptor Beta in Alcoholic Liver Diseases

酒精性肝病(ALD)是美国发病率和死亡率的主要原因，与 非酒精性脂肪性肝病/脂肪性肝炎(NAFLD/NASH)，正在成为 因肝移植住院治疗。ALD虽然最初没有症状，但以脂肪变性为特征 并增加炎症，随着时间的推移会发展成更严重的情况，最终导致 肝硬变和肝功能衰竭。ALD的发病机制尚不完全清楚，这阻碍了ALD的发展。 制定治疗方案，不仅要处理酒精相关的疾病，而且还要处理随后的致命疾病 肝功能衰竭等病症。ALD与NAFLD/NASH具有相同的分子和组织病理学特征， 包括脂肪变性增加，氧活性物质(ROS)产生过多，炎症，特别是 破坏脂代谢的关键调节因子维甲酸受体β(RARβ)。我们的研究小组 最近的研究表明，RARβ信号的中断在非酒精性脂肪肝/非酒精性脂肪肝和非酒精性脂肪肝的发生发展中起关键作用。 小鼠糖尿病状态，以及高选择性RARβ2激动剂AC261066的治疗，导致 改善糖耐量，减少脂肪变性、ROS和炎症。这些发现强调了 RARβ作为管理代谢紊乱的潜在靶点的核心作用和证明 AC261066可能是治疗这些疾病的有用药物。基于年内取得的令人鼓舞的结果 在非酒精性脂肪肝/非酒精性脂肪肝小鼠模型中，我们假设RARβ信号通路的破坏是一个关键 ALD发生中的因素和AC261066的治疗可以预防或逆转 酒精相关性肝病的进展。为了验证这一假设，我们将使用体外模型和 模拟ALD的慢性酒精滥用的活体小鼠模型。我们提出了以下具体目标： 具体目标(1)：确定AC261066是否可以预防乙醇毒性，并确定RARβ2是否是必需的 为了达到这个效果。我们将用乙醇处理人肝细胞，并测量代谢和表达 在AC261066存在或不存在的情况下，与氧化应激和细胞凋亡相关的基因。在一个 通过单独的一系列实验，我们将确定AC261066的作用是否依赖于RARβ2。 具体目标(2)：确定AC261066是否能预防乙醇毒性并探讨其机制 在小鼠模型中的作用。为此，我们将使用一种慢性酒精摄入的小鼠模型，模拟 ALD.我们将在献祭前测量代谢状态，并随后进行转录分析 采用RNA-Seq、组织学和病理学方法。

Alcoholic liver disease (ALD) is a major cause of morbidity and mortality in the U.S, and together with nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH), is becoming the most common cause of hospitalization for liver transplantation. ALD, while initially asymptomatic, is characterized by steatosis and increased inflammation, and over time progresses toward a more serious condition, culminating in cirrhosis and liver failure. The pathogenesis of ALD is not fully understood which hinders the develop- ment of therapeutic options to manage not only alcohol-related disorders but also subsequent, fatal conditions such as liver failure. ALD shares molecular and histopathologic features with NAFLD/NASH, including increased steatosis, overproduction of oxygen reactive species (ROS), inflammation, and notably disruption of a key regulator of lipid metabolism, retinoic acid receptor beta (RARβ). Our research group has recently shown that disruption of RARβ signaling is critical in the development of NAFLD/NASH and the diabetic state in mice, and that treatment with a highly selective RARβ2 agonist, AC261066, resulted in improved glucose tolerance, and decreased steatosis, ROS, and inflammation. These findings underscore the central role of RARβ as a potential target to manage metabolic disorders and demonstrate that AC261066 could be a useful drug for treating these disorders. Based on the encouraging results obtained in NAFLD/NASH mice models, we hypothesize that the disruption of the RARβ signaling pathway is a key factor in the development of ALD and that treatment with AC261066 can prevent or reverse the progression of alcohol-related liver disorders. To test this hypothesis, we will use an in vitro model and an in vivo mouse model of chronic alcohol abuse that mimics ALD. We propose the following specific aims: Specific Aim (1): Determine if AC261066 prevents ethanol toxicity and determine if RARβ2 is essential for this effect. We will treat human hepatocytes with ethanol and measure metabolism and the expression of genes associated with oxidative stress and apoptosis in the presence or absence of AC261066. In a separate series of experiments, we will determine if the effects of AC261066 are dependent on RARβ2. Specific Aim (2): Determine if AC261066 prevents ethanol toxicity and explore the mechanisms of this effect in a murine model. For this aim we will use a mouse model of chronic ethanol intake that mimics ALD. We will measure the metabolic state prior to sacrifice and will follow with transcriptomic analyses using RNA-Seq, histology and pathology approaches.