Mitochondrial GSH /SAM in alcohol induced liver damage

线粒体 GSH /SAM 在酒精性肝损伤中的作用

• 批准号: 6795964
• 负责人: JOSE C FERNANDEZ-CHECA
• 金额: $ 10.8万
• 依托单位: FUNDACIO CLINIC
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6795964
• 关键词: Kupffer' s cell; S adenosylmethionine; alcoholic fatty liver; alcoholic hepatitis; alcoholic liver cirrhosis; alcoholism /alcohol abuse; biological transport; cholesterol; dietary supplements; ethanol; gene expression; gene targeting; genetically modified animals; glutathione; glycosphingolipids; laboratory mouse; laboratory rat; liver pharmacology; membrane permeability; mitochondria; mitochondrial membrane; nutrition related tag; pathologic process; phosphodiesterases; sphingomyelin phosphodiesterase; tissue /cell culture; tumor necrosis factor alpha

DESCRIPTION (provided by applicant): Since we first discovered in 1987 the depletion of mitochondrial GSH (mGSH) status by chronic ethanol intake, considerable progress has been made regarding the molecular mechanism(s) of the defect and its functional impact in alcohol-induced liver damage (ALD). In addition to the altered regulation of mGSH by alcohol, S-adenosyl-L-methionine (SAM) depletion has been also reported and is thought to contribute to the progression of the disease. GSH and SAM may exhibit parallel features as both are found in mitochondria due to specific transport mechanisms. Thus, the present proposal will look at the specific regulation of mitochondrial SAM (mSAM) pool by alcohol and the temporal and functional relationship between mGSH and mSAM by alcohol. 1. - SAM levels and transport in rat liver mitochondria from alcohol-fed rats. Most studies have reported the status of total SAM levels in hepatocellular extracts in patients and experimental models of ALD. We wilt examine the status of mSAM levels and its mitoehondrial transport in chronic alcohol-fed rats. 2. Temporal and functional relationship between mitochondrial GSH and SAM depletion by alcohol: Role of Kupffer cells and liver steatosis. We will examine if mGSH depletion by alcohol precedes or follows that of SAM (total and mSAM) in mitochondria from alcohol fed rats and its relationship with pathology. The role of Kupffer cell activation and liver steatosis on alcohol-mediated mGSH and total SAM (cytosol and mSAM) depletion will be evaluated in alcohol-fed rats and in a model of non-alcohol: hepatic steatosis. 3. Mechanism whereby SAM feeding normalizes the alcohol-altered mitoehondrial membrane fluidity and mGSH transport. Increasing evidence indicate a critical role of cholesterol/phospholipid molar ratio in the regulation of mitochondrial membrane mieroviseosity and mGSH transport, in addition to these changes, we wilt examine the regulation and trafficking of cholesterol into mitoehondria, as well as the fatty acid composition of individual lipids of mitochondrial lipid classes from chronic alcohol-fed rats with or without SAM supplementation. 4. Regulation of MAT1A by glycosphingolipids and sphingomyelinases. TNF and short-chain ceramide have been reported to downregulate the expression of MAT1A. Since sphingomyelinases (SMases) are known to mediate some of the effects of TNF, we will examine the role of individual neutral or acidic SMase, in the regulation of MATIA in primary cultured rat hepatocytes and HepG2 cells exposed to exogenous neutral (NSMase) or acid (ASMase) SMases. In addition, we will assess the role of TNF on MATIA expression in ASMase knockout mice.

描述（由申请人提供）：自从我们于1987年首次发现慢性乙醇摄入的线粒体GSH（MGSH）状态的耗竭，因此在缺陷的分子机制及其在酒精诱导的肝损害（ALD）中的功能影响方面取得了长足的进步。除了通过酒精对MGSH调控的改变外，还报道了S-腺苷-l-甲硫代（SAM）耗竭，并被认为有助于该疾病的进展。由于特定的运输机制，GSH和SAM在线粒体中都可能表现出平行的特征。因此，本提案将通过酒精以及通过酒精对MGSH和MSAM之间的时间和功能关系来研究线粒体SAM（MSAM）池的特定调节。 1。-大鼠肝脏线粒体的SAM水平和转运来自酒精喂养的大鼠。大多数研究报告了患者和ALD实验模型的肝细胞提取物中SAM总水平的状态。我们枯萎检查了MSAM水平的状态及其在慢性酒精喂养大鼠中的MitoeHondrial运输。 2。线粒体GSH与饮酒的SAM消耗之间的时间和功能关系：Kupffer细胞和肝脏脂肪变性的作用。我们将检查酒精之前的MGSH耗竭或遵循饮酒大鼠的线粒体中SAM（总和MSAM）的耗尽及其与病理学的关系。 Kupffer细胞活化和肝脏脂肪变性在酒精介导的MGSH和总SAM（细胞质和MSAM）耗竭的作用中，将在酒精喂养的大鼠以及非酒精：肝脂肪变性的模型中进行评估。 3. SAM喂养的机制可以使饮酒改变的线粒体膜流动性和MGSH转运归一化。越来越多的证据表明，胆固醇/磷脂摩尔比在线粒体膜膜的调节中的关键作用以及MGSH转运的调节，除了这些变化外，我们还研究了胆固醇的调节和运输，研究了胆固醇对线粒体的脂肪酸脂肪酸的脂肪酸的脂肪酸的脂肪酸分类，以及脂肪中的脂肪酸性分类。补充。 4。通过糖脂脂和鞘磷脂酶调节MAT1A。据报道，TNF和短链神经酰胺下调MAT1A的表达。由于已知鞘氨质酶（SMase）介导了TNF的某些作用，因此我们将检查单个中性或酸性SMase的作用，在原代培养的大鼠肝细胞中Matia调节Matia和暴露于外源性中性（NSMASE）或酸（NSMASE）或酸（Acid Asmase）Smases中的Matia的作用。此外，我们将评估TNF在ASMase敲除小鼠中MATIA表达的作用。