In vivo tracing of hepatic ethanol metabolism to histone acetylation: role of ACSS2 in alcohol-induced liver injury

肝脏乙醇代谢与组蛋白乙酰化的体内追踪：ACSS2 在酒精性肝损伤中的作用

基本信息

批准号：
10667952
负责人：
BRANT Roger BURKHARDT
金额：
$ 21.43万
依托单位：
UNIVERSITY OF SOUTH FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-05-20 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10667952
关键词：
Acetates Acetyl Coenzyme A Acetylation Acute Alcohol consumption Alcoholic Liver Diseases Alcohols Animal Model Area Biological Cell Culture Techniques Cell Nucleus Cell physiology Cessation of life Chromatin Chronic Code Data Development Enzymes Epigenetic Process Ethanol Ethanol Metabolism FDA approved Fatty Liver Foundations Future Gene Deletion Genes Genetic Genetic Transcription Health Hepatic Hepatocyte High Fat Diet Histone Acetylation Histone H3 Histones Human Inflammation Knockout Mice Label Link Liver Liver diseases Mass Spectrum Analysis Mediating Metabolic Metabolism Modeling Modification National Institute on Alcohol Abuse and Alcoholism Outcome Oxidative Stress Pathogenesis Pathway interactions Phenotype Play Process Promoter Regions Proteins Proteome Regulation Research Resolution Risk Factors Role SIRT1 gene Signal Transduction Site Testing Therapeutic Intervention Transcription Process Validation alcohol effect alcohol exposure alcohol misuse chromatin immunoprecipitation chronic alcohol ingestion chronic liver disease epigenome fascinate histone acetyltransferase histone modification in vivo insight lipid biosynthesis lipid metabolism liver injury mouse model next generation sequencing novel pharmacologic promoter protein structure stable isotope therapeutic target

项目摘要

ABSTRACT Chronic alcohol misuse is a major risk factor for alcohol-associated liver disease, a serious health condition that represents approximately 50% of deaths in the U.S. related to chronic liver disease. Known pathophysiological processes associated with alcohol-induced liver injury (ALI) include oxidative stress, alteration of cell signaling, and inflammation; however, little is known about the effects of alcohol on the hepatic epigenome, an emerging area with significant implications in the pathogenesis and progression of ALI. Specifically, changes in histone acetylation, which includes the alcohol-induced H3K9Ac chromatin mark, have been observed in several studies utilizing various cell culture and animal models of acute and chronic alcohol exposure. A key feature of alcohol-induced histone acetylation changes is that ethanol-derived metabolites can be incorporated directly into the hepatic epigenome (i.e., acetate to Acetyl-CoA used for histone acetylation), which could have a significant impact on transcriptional processes and subsequent pathophysiological outcomes related to chronic alcohol use. Interestingly, ACSS2, a nucleocytosolic enzyme that catalyzes the conversion of acetate to Acetyl-CoA, has recently been shown to play a role in regulation of lipid metabolism genes where deletion of Acss2 protects against high fat diet-induced hepatic steatosis. However, in the context of alcohol-induced hepatic steatosis and associated histone acetylation changes, the role of ACSS2 is essentially unknown. We propose a novel metabolic tracing approach using stable isotope (non- radioactive)-labeled ethanol and high-resolution mass spectrometry to accurately quantify the contribution of ethanol-derived Acetyl-CoA and ACSS2 to hepatic histone acetylation at site-specific levels in a chronic plus binge alcohol exposure model. We hypothesize that ethanol metabolism as well as ACSS2 activity will enhance alcohol-induced hepatic histone acetylation and that enrichment of these histone acetylation sites occurs at gene/gene promoter regions associated with markers and/or pathways relevant to alcohol-induced liver injury phenotype. To test this hypothesis, we will 1) quantify the hepatocyte-specific contribution of Acetyl-CoA derived from ethanol metabolism and ACSS2 activity to histone acetylation in a mouse model of chronic ethanol exposure and 2) determine the impact of site-specific histone acetylation increases induced by ethanol metabolism and ACSS2 activity on ALI phenotype. The results from this project could reveal a novel link between alcohol-induced changes in hepatic histone acetylation and liver injury phenotype, ultimately providing a foundation to guide future mechanistic studies related to the specific role of ACSS2 in the progression of severe liver injury brought about by excessive alcohol misuse.

抽象的慢性酒精滥用是酒精相关性肝病的主要危险因素，酒精性肝病是一种严重的健康问题在美国，约 50% 的死亡与慢性肝病有关。已知与酒精性肝损伤 (ALI) 相关的病理生理过程包括氧化压力、细胞信号传导的改变和炎症；然而，人们对酒精的影响知之甚少肝脏表观基因组是一个对发病机制和发病机制具有重要影响的新兴领域 ALI 的进展。具体来说，组蛋白乙酰化的变化，包括酒精诱导的 H3K9Ac 染色质标记，已在利用各种细胞培养物和动物的多项研究中观察到急性和慢性酒精暴露模型。酒精诱导的组蛋白乙酰化的一个关键特征变化在于乙醇衍生的代谢物可以直接掺入肝脏表观基因组（即用于组蛋白乙酰化的乙酸盐到乙酰辅酶A），可能具有显着的影响对慢性病相关转录过程和随后的病理生理结果的影响酒精的使用。有趣的是，ACSS2，一种催化乙酸盐转化的核胞质酶乙酰辅酶A，最近被证明在脂质代谢基因的调节中发挥作用，其中 Acss2 的缺失可以防止高脂肪饮食引起的肝脂肪变性。然而，在这样的背景下酒精引起的肝脂肪变性和相关的组蛋白乙酰化变化，ACSS2 的作用是本质上是未知的。我们提出了一种使用稳定同位素（非放射性）标记的乙醇和高分辨率质谱法可准确定量乙醇衍生的乙酰辅酶A和ACSS2对肝组蛋白位点特异性乙酰化的贡献慢性加狂饮酒精暴露模型中的水平。我们假设乙醇代谢为 ACSS2 活性将增强酒精诱导的肝组蛋白乙酰化，并且富集这些组蛋白乙酰化位点发生在与标记相关的基因/基因启动子区域和/或与酒精性肝损伤表型相关的途径。为了检验这个假设，我们将 1）量化来自乙醇代谢和 ACSS2 活性的乙酰辅酶 A 的肝细胞特异性贡献慢性乙醇暴露小鼠模型中组蛋白乙酰化的影响，2) 确定 ALI 中乙醇代谢和 ACSS2 活性诱导位点特异性组蛋白乙酰化增加表型。该项目的结果可能揭示酒精引起的变化之间的新联系肝组蛋白乙酰化和肝损伤表型，最终为指导未来提供基础与ACSS2在严重肝损伤进展中的具体作用相关的机制研究过度滥用酒精造成的。