Diaphragm Mitochondrial Alterations in Sepsis

描述（申请人摘要）：最近的研究表明，线粒体 功能障碍在脓毒症中起中心作用，脓毒症是死亡的主要原因， 美国的发病率。造成这种情况的潜在机制 线粒体功能障碍是未知的。本提案的目标是 检验脓毒症中自由基生成增加 特定的生物化学、结构和遗传变化， 线粒体功能的生理改变。我们假设：（a） 脓毒症中线粒体功能障碍是由于 Krebs循环酶，复合物I-IV电子传递链组分，和 肌节肌酸激酶，（B）这些生理变化是由于，反过来， 线粒体蛋白质的含量和组成的改变，以及（c） 蛋白质的变化部分是由于自由基介导的蛋白质的减少， 线粒体基因转录、表达和翻译。这些假设 将在三组实验中进行测试，使用 内毒素引起的败血症目标1的目的是充分表征 败血症中线粒体的特定生理紊乱;我们将 检查Krebs循环酶活性，评价 复合物内的电子传递链，评估肌节线粒体 肌酸激酶活性，并进行代谢控制分析。目的 II将确定线粒体的内容和组成的变化， 蛋白质成分（即电子传递链蛋白亚基，Krebs 循环酶，肌酸激酶），并比较这些 随着生理异常的发展而改变， 目标一目的III将评估转录，表达， 线粒体和编码线粒体DNA的核基因的翻译 在目标II中发现被耗尽的蛋白质。在所有研究中，我们将 确定这些脓毒症引起的变化的自由基调制的作用。 我们的初步数据提供了第一个证据 脓毒症相关线粒体蛋白氧化修饰和耗竭 复合物I、III和IV中的亚基，NADH生成的显著改变 通过克雷布斯循环酶，线粒体肌酸激酶 活性和关键自由基介导的基因表达变化， 线粒体蛋白在败血症中的作用这些数据表明， 实验应该提供关于发病机制的重要信息， 败血症中的线粒体功能障碍

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.