GSH MEDIATED DETOXIFICATION OF HNE IN MITOCHONDIRA

我们实验室和其他实验室一致的发现是肝毒 对酒精摄入的反应包括线粒体(M)损伤 呼吸和氧化应激的诱导。我们最近的研究表明 证明了一种脂质过氧化的有毒产物，4-羟基壬烯醛 (HNE)抑制细胞色素C氧化酶(CO)，细胞色素C氧化酶是细胞色素C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。初步研究表明， 谷胱甘肽S转移酶介导的HNE与GSH的偶联是一种 是抵御HNE抑制CO的重要防线。乙醇 消耗M中的GSH，它可以改变GST活性，并与乙醇相关 氧化应激在M体内产生HNE，因此，我们建议确定 乙醇摄取对GST介导的HNE解毒作用的影响 并确定补充GSH的方案，以防止这种情况发生。 假设。我们假设一个重要的细胞防御系统 乙醇相关氧化应激对一氧化碳的抑制作用 线粒体GST介导HNE与乙醇偶联 消费会损害这种解毒系统。 明确的目标。1.定量检测线粒体GST在大鼠脑缺血再灌注中的作用 对在M中产生的HNE的解毒作用2.确定 线粒体GST/HNE结合系统的乙醇消耗和 确定建立这种防御机制的条件 在酒精暴露期间发挥最佳功能。 实验。这些研究将利用大鼠肝脏中的M来建立 急、慢性摄入E对GST-HNE结合系统的影响 终点是GSH-HNE偶联物的产生，CO的抑制， 和HNE-CO加合物的形成(HNE抑制CO的一种方式)。 此外，酒精对谷胱甘肽M池的归一化作用 这些参数的消耗量将被确定。 综上所述，乙醇相关的氧化应激在M中产生HNE 或者在CO的位置附近，这种HNE抑制该酶。 此外，乙醇会耗尽谷胱甘肽所需的细胞器 GST介导的HNE结合可以阻止CO的这种抑制。 我们认为，这是一种新的、尚未记录在案的机制， 一个关键的M功能可以免受乙醇诱导的氧化应激的影响。 这是这项探索性提案的重点。

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.