GSH MEDIATED DETOXIFICATION OF HNE IN MITOCHONDIRA

GSH 介导线粒体中 HNE 的解毒

• 批准号: 2825835
• 负责人: GEORGE I HENDERSON
• 金额: $ 10.1万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2825835
• 关键词: adduct; alcoholic beverage consumption; aldehydes; cytochrome oxidase; detoxification; ethanol; glutathione; glutathione transferase; high performance liquid chromatography; laboratory rat; mitochondria; oxidative stress; oxidoreductase inhibitor

Consistent findings from our laboratory and others are that hepatoxic responses to ethanol consumption include damage to mitochondrial (M) respiration and induction of oxidative stress. Recent studies by us have documented that a toxic product of lipid peroxidation, 4-hydroxynonenal (HNE) inhibits cytochrome c oxidase (CO), a key component of the respiratory chain. This may be one mechanism by which ethanol inhibits M energy production. Preliminary studies, have illustrated that glutathione S transferase (GST)-mediated HNE conjugation with GSH is an important line of defense against the inhibition of CO by HNE. Ethanol depletes M of GSH, it can alter GST activity, and ethanol-related oxidative stress produces HNE within M. Thus, we propose to determine the effects of ethanol consumption on GST-mediated detoxification of HNE and define regimens of GSH repletion which may prevent this. Hypothesis. We hypothesize that an important cellular defense against the inhibition of CO by ethanol-related oxidative stress is mitochondrial GST-mediated conjugation of HNE and that ethanol consumption can impair this detoxification system. Specific Aims. 1. Quantitate the role of mitochondrial GST in the detoxification of HNE generated within M. 2. Determine the effects of ethanol consumption on the mitochondrial GST/HNE conjugation system and ascertain the conditions under which this defense mechanism can be made to function optimally during ethanol exposure. Experiments. The studies will utilize M from rat livers to establish effects of acute and chronic E intake on the GST-HNE conjugating system, with endpoints being production of GSH-HNE conjugates, inhibition of CO, and formation of HNE-CO adducts (a means by which HNE inhibits CO). Additionally, the effects of normalizing M pools of GSH during ethanol consumption on these parameters will be determined. In Summary, ethanol-related oxidative stress produces HNE within M at or near the location of CO and this HNE inhibits the enzyme. Additionally, ethanol can deplete the organelle of GSH needed for the GST-mediated HNE conjugation that can prevent this inhibition of CO. We submit that this is a new and yet to be documented mechanism by which a key M function can be protected from ethanol-induced oxidative stress. It is the focus of this exploratory proposal.

我们实验室和其他实验室的一致发现是肝毒性 对乙醇消耗的反应包括对线粒体的损​​害（M） 氧化应激的呼吸和诱导。我们最近的研究 记录了脂质过氧化的有毒产物，4-羟基诺纳尔 （HNE）抑制细胞色素c氧化酶（CO），这是该的关键成分 呼吸链。 这可能是乙醇抑制的一种机制 M能源生产。初步研究已经说明了 谷胱甘肽的转移酶（GST）介导的HNE与GSH共轭是 对HNE抑制CO的重要防御线。乙醇 耗尽GSH，它可以改变GST活性并与乙醇相关 氧化应激会在M内产生HNE。因此，我们建议确定 乙醇消耗对GST介导的HNE排毒的影响 并定义了GSH补充方案，这可能会阻止这种情况。 假设。 我们假设一个重要的蜂窝防御 通过乙醇相关的氧化应激对CO的抑制是 线粒体GST介导的HNE和乙醇的结合 消费会损害这种解毒系统。 具体目标。 1。定量线粒体GST在 M. 2中产生的HNE的排毒。确定 线粒体GST/HNE共轭系统上的乙醇消耗和 确定可以做出这种防御机制的条件 在乙醇暴露期间发挥最佳功能。 实验。研究将利用大鼠肝脏建立M 急性和慢性E摄入对GST-HNE共轭系统的影响， 终点是生产GSH-HNE共轭物，抑制CO， 和HNE-CO加合物的形成（HNE抑制CO的手段）。 此外，在乙醇期间使GSH的M池归一化的效果 将确定这些参数的消费。 总而言之，乙醇相关的氧化应激会在M内产生HNE 或附近CO的位置，此HNE抑制酶。 此外，乙醇可以耗尽GSH的细胞器 GST介导的HNE结合可以防止这种抑制CO。 我们认为这是一种新的尚未记录在上面的机制 可以保护关键M功能免受乙醇诱导的氧化应激。 这是该探索性建议的重点。