Diaphragm Mitochondrial Alterations in Sepsis

脓毒症中的隔膜线粒体改变

• 批准号: 7365401
• 负责人: LEIGH A CALLAHAN
• 金额: $ 22.72万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7365401
• 关键词: Krebs' cycle; bacterial disease; blood toxicology; creatine kinase; diaphragm; electron transport; endotoxins; enzyme activity; enzyme inhibitors; free radical scavengers; gel electrophoresis; glycosides; laboratory rat; lipopolysaccharides; microarray technology; mitochondria; nicotinamide adenine dinucleotide; nitric oxide synthase; oxidative phosphorylation; oxygen consumption; polymerase chain reaction; sarcomeres; spectrometry

DESCRIPTION (Applicant's abstract): Recent work suggests that mitochondria dysfunction plays a central role in sepsis, a major cause of death and morbidity in the United States. The underlying mechanisms responsible for this mitochondria dysfunction are not known. The goal of the present proposal is to test the hypothesis that increased free radical generation in sepsis produces specific biochemical, structural and genetic changes that result in marked physiologic alterations in mitochondrial function. We postulate: (a) mitochondria dysfunction in sepsis results from physiologic derangements of Krebs cycle enzymes, Complex I-IV electron transport chain components, and sarcomericcreatine kinase, (b) these physiologic changes are due, in turn, to alterations in the content and composition of mitochondrial proteins, and (c) protein changes are due, in part, to free radical-mediated decrements in mitochondrial gene transcription, expression, and translation. These hypotheses will be tested in three groups of experiments, using a model of endotoxin-induced sepsis. The purpose of Objective 1 is to fully characterize the specific physiologic derangements in the mitochondria in sepsis; we will examine Krebs cycle enzyme activities, evaluate specific performance of complexes within the electron transport chain, assess sarcomeric mitochondrial creatine kinase activity, and perform a metabolic control analysis. Objective II will identify changes in the content and composition of mitochondrial protein constituents (i.e. electron transport chain protein subunits, Krebs cycle enzymes, creatine kinase) and compare the time course of these alterations with the development of physiologic abnormalities determined in Objective I. Objective III will evaluate transcription, expression, and translation of mitochondria and nuclear genes encoding for mitochondrial proteins found to be depleted in Objective II. In all studies, we will determine the role of free radical modulation of these sepsis-induced changes. Our preliminary data provide the first evidence of substantial sepsis-associated oxidative modification and depletion of mitochondria protein subunits in Complexes I, III and IV, significant alterations in NADH generation via Krebs cycle enzymes, major decreases in mitochondria creatine kinase activity, and key free radical-mediated changes in gene expression of mitochondrial proteins in sepsis. These data suggest that the proposed experiments should provide important information regarding the pathogenesis of mitochondrial dysfunction in sepsis.

描述（申请人的摘要）：最近的工作表明线粒体 功能障碍在败血症中起着核心作用，败血症是死亡和死亡的主要原因 美国的发病率。造成这种情况的底层机制 线粒体功能障碍尚不清楚。本提案的目标是 检验脓毒症中自由基生成增加的假设 特定的生化、结构和遗传变化，导致显着的 线粒体功能的生理改变。我们假设：（a） 脓毒症中的线粒体功能障碍是由生理紊乱引起的 克雷布斯循环酶、复合物 I-IV 电子传递链组分，以及 肌节肌酸激酶，(b) 这些生理变化反过来是由于 线粒体蛋白质的含量和组成的改变，以及（c） 蛋白质变化部分是由于自由基介导的减少 线粒体基因转录、表达和翻译。这些假设 将使用以下模型在三组实验中进行测试 内毒素引起的败血症。目标 1 的目的是充分表征 脓毒症中线粒体的特定生理紊乱；我们将 检查克雷布斯循环酶活性，评估特定性能 电子传递链内的复合物，评估肌节线粒体 肌酸激酶活性，并进行代谢控制分析。客观的 II 将确定线粒体含量和组成的变化 蛋白质成分（即电子传递链蛋白质亚基、克雷布斯 循环酶、肌酸激酶）并比较这些的时间进程 随着生理异常的发展而改变 目标 I. 目标 III 将评估转录、表达和 线粒体和编码线粒体的核基因的翻译 发现目标 II 中的蛋白质被耗尽。在所有的研究中，我们将 确定自由基调节这些脓毒症引起的变化的作用。 我们的初步数据提供了实质性证据 败血症相关的氧化修饰和线粒体蛋白的消耗 复合物 I、III 和 IV 中的亚基，NADH 生成发生显着变化 通过克雷布斯循环酶，线粒体肌酸激酶显着减少 活性以及自由基介导的基因表达的关键变化 脓毒症中的线粒体蛋白。这些数据表明，拟议的 实验应提供有关发病机制的重要信息 脓毒症中的线粒体功能障碍。