Homocysteine and Alcoholic Liver Disease

同型半胱氨酸和酒精性肝病

• 批准号: 7649068
• 负责人: Donald Weldon Jacobsen
• 金额: $ 39.25万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7649068
• 关键词: Address; Alcohol abuse; Alcohol consumption; Alcoholic Liver Diseases; Alcoholism; Alcohols; Apoptosis; Biological Assay; Blood; Carbon; Cells; Chronic; Cirrhosis; Clinical; Cytochrome P-450 CYP2E1; Data; Detection; Disease Progression; Endoplasmic Reticulum; Enzyme-Linked Immunosorbent Assay; Enzymes; Ethanol; Ethanol toxicity; Fluorescence; Functional disorder; Future; Generations; Hepatocyte; High Pressure Liquid Chromatography; Homocysteine; Homocystine; Human; Hyperhomocysteinemia; Immunoprecipitation; Individual; Injury; Lead; Liver; Mediating; Metallothionein; Methionine; Modeling; Molecular; Molecular Chaperones; Molecular Target; Morbidity - disease rate; Organ; Oxidative Stress; Oxidative Stress Induction; Pathway Analysis; Pathway interactions; Patients; Process; Production; Proteins; Proteome; Proteomics; Protocols documentation; Public Health; Rattus; Reactive Oxygen Species; Research; Role; Sodium Dodecyl Sulfate-PAGE; Staging; Steatohepatitis; Testing; Therapeutic; Time; Tissues; Western Blotting; alcohol research; design; economic impact; endoplasmic reticulum stress; feeding; in vivo; insight; mRNA Expression; mortality; novel; novel therapeutic intervention; public health relevance; response

DESCRIPTION (provided by applicant): The public health issues, economic impact and human suffering associated with alcohol abuse are staggering. Although alcohol-related research has been on-going for decades, there are many unanswered questions concerning mechanisms of alcohol-induced tissue injury. Elevated blood homocysteine (hyperhomocysteinemia) is strongly associated with chronic alcoholism. However, the molecular mechanism of elevated homocysteine in alcohol abusers is largely unknown. Of greater importance is the pathological impact and clinical consequences of hyperhomocysteinemia in these individuals. This proposal will provide novel information on the role of methionine synthase (MS) in alcohol-associated hyperhomocysteinemia, homocysteine-induced oxidative and endoplasmic reticulum (ER) stress in models of alcoholic liver disease (ALD), and changes in the one-carbon proteome and metabolome of alcohol-treated cells and liver. The central hypotheses that drive this project are: 1) alcohol-induced oxidative stress in the liver will lead to the inactivation of B12-dependent MS; 2) impaired remethylation of homocysteine results in elevated intracellular homocysteine and hyperhomocysteinemia; 3) molecular targeting of specific intracellular proteins by homocysteine causes enhanced production of reactive oxygen species (ROS), ER stress, and apoptosis; and, 4) the one-carbon proteome and metabolome of the liver is substantially altered in ALD. The specific aims of this project are: 1. to determine the mechanism of inactivation of B12-dependent MS in alcohol-treated cells in culture and in livers from ethanol-fed rats; 2. to establish the role that molecular targeting of specific proteins by L-homocysteine has in the generation of oxidative stress and in the induction of ER stress in alcohol-treated cells and rats; and, 3. to determine whether the decreased SAM/SAH ratio that accompanies ALD is (a) a direct result of alcohol or its metabolites on the levels and/or activities of the methionine cycle enzymes, or (b) an indirect result of the hyperhomocysteinemia that accompanies increased alcohol consumption. These hypotheses will be tested at the cellular level using cultured alcohol-treated or untreated HepG2 E47 and C34 cells and in vivo using livers from rats on the Lieber-DeCarli ethanol feeding model and pair-fed controls. The mechanistic insight gained from this proposal may be useful for establishing novel therapeutic interventions in the treatment of alcoholic liver disease. PUBLIC HEALTH RELEVANCE: The public health issues, economic impact and human suffering associated with alcohol abuse are staggering. Elevated blood homocysteine (hyperhomocysteinemia) is strongly associated with chronic alcoholism. However, the molecular cause of elevated homocysteine and its role in mediating tissue injury in alcoholism is largely unknown. This proposal will provide mechanistic insight on the cause of hyperhomocysteinemia and its deleterious effects to tissues in chronic alcohol abuse.

描述（由申请人提供）：与酗酒相关的公共卫生问题、经济影响和人类痛苦是令人震惊的。尽管与酒精相关的研究已经持续了几十年，但关于酒精引起的组织损伤的机制仍有许多悬而未决的问题。血液同型半胱氨酸升高（高同型半胱氨酸血症）与慢性酒精中毒密切相关。然而，酗酒者同型半胱氨酸升高的分子机制尚不清楚。更重要的是这些个体中高同型半胱氨酸血症的病理影响和临床后果。该提案将提供有关蛋氨酸合酶（MS）在酒精相关高同型半胱氨酸血症中的作用、酒精性肝病（ALD）模型中同型半胱氨酸诱导的氧化和内质网（ER）应激以及一碳蛋白质组变化的新信息以及酒精处理的细胞和肝脏的代谢组。推动该项目的核心假设是：1）酒精诱导的肝脏氧化应激将导致 B12 依赖性 MS 失活； 2）同型半胱氨酸的再甲基化受损导致细胞内同型半胱氨酸升高和高同型半胱氨酸血症； 3) 同型半胱氨酸对特定细胞内蛋白质的分子靶向导致活性氧 (ROS) 产生增加、内质网应激和细胞凋亡； 4) ALD 中肝脏的一碳蛋白质组和代谢组发生显着改变。该项目的具体目标是： 1. 确定酒精处理的培养细胞和乙醇喂养大鼠肝脏中 B12 依赖性 MS 失活的机制； 2. 确定L-同型半胱氨酸对特定蛋白质的分子靶向在酒精处理的细胞和大鼠中产生氧化应激和诱导内质网应激中的作用； 3. 确定伴随 ALD 的 SAM/SAH 比率降低是否是 (a) 酒精或其代谢物对甲硫氨酸循环酶的水平和/或活性的直接结果，或 (b) 酒精或其代谢物对甲硫氨酸循环酶的水平和/或活性的间接结果伴随饮酒量增加的高同型半胱氨酸血症。这些假设将使用培养的酒精处理或未处理的 HepG2 E47 和 C34 细胞在细胞水平上进行测试，并使用 Lieber-DeCarli 乙醇喂养模型和配对喂养对照大鼠的肝脏进行体内测试。从该提案中获得的机制见解可能有助于建立治疗酒精性肝病的新型治疗干预措施。公共卫生相关性：与酗酒相关的公共卫生问题、经济影响和人类痛苦令人震惊。血液同型半胱氨酸升高（高同型半胱氨酸血症）与慢性酒精中毒密切相关。然而，同型半胱氨酸升高的分子原因及其在介导酒精中毒组织损伤中的作用尚不清楚。该提案将为高同型半胱氨酸血症的原因及其对慢性酒精滥用组织的有害影响提供机制见解。