GSH MEDIATED DETOXIFICATION OF HNE IN MITOCHONDIRA

GSH 介导线粒体中 HNE 的解毒

基本信息

批准号：
6168479
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
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-04-01 至 2002-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6168479
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

项目摘要

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线粒体损伤（M）呼吸和氧化应激的诱导。我们最近的研究有据记载，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)，这是细胞色素 C 氧化酶的关键成分呼吸链。这可能是乙醇抑制 M 能源生产。初步研究表明谷胱甘肽 S 转移酶 (GST) 介导的 HNE 与 GSH 结合是一种 HNE 抑制 CO 的重要防线。乙醇消耗 GSH 的 M，它可以改变 GST 活性，以及与乙醇相关的氧化应激在 M 内产生 HNE。因此，我们建议确定乙醇消耗对 GST 介导的 HNE 解毒的影响并制定可以预防这种情况的 GSH 补充方案。假设。我们假设一种重要的细胞防御机制乙醇相关的氧化应激对 CO 的抑制作用是线粒体 GST 介导的 HNE 与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 内产生的 HNE 的解毒。 2. 确定线粒体 GST/HNE 缀合系统的乙醇消耗和确定建立这种防御机制的条件在乙醇暴露期间发挥最佳功能。实验。该研究将利用大鼠肝脏中的 M 来建立急性和慢性E摄入对GST-HNE结合系统的影响，终点是 GSH-HNE 缀合物的产生、CO 的抑制、 HNE-CO 加合物的形成（HNE 抑制 CO 的一种方式）。此外，乙醇过程中 GSH M 池标准化的影响这些参数的消耗将被确定。总之，乙醇相关的氧化应激在 M 内产生 HNE 或靠近 CO 的位置，并且该 HNE 抑制该酶。此外，乙醇会耗尽细胞所需的谷胱甘肽（GSH）。 GST 介导的 HNE 缀合可以阻止 CO 的这种抑制。我们认为这是一个新的、尚未记录的机制，通过该机制一个关键的 M 功能可以保护免受乙醇诱导的氧化应激。这是本次探索性提案的重点。