Nitric oxide and mitochondrial biogenesis in sepsis

脓毒症中的一氧化氮和线粒体生物发生

基本信息

批准号：
8534342
负责人：
CLAUDE A PIANTADOSI
金额：
$ 31.4万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-23 至 2014-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8534342
关键词：
5&apos -AMP-activated protein kinase Acute Adenosine Monophosphate Antibiotics Apoptosis Autophagocytosis Biogenesis Biological Models Biology CREB1 gene Caring Cell Death Cell Nucleus Cell Survival Chemical Warfare Chemicals Complex Critical Illness Data Development Failure Genes Genetic Goals Gram-Positive Bacteria Grant Hepatic Hepatocyte Hypoxia Infection Inflammation Inflammatory Knowledge Learning Link Liver Mediating Mediator of activation protein Mitochondria Mitochondrial DNA Multiple Organ Failure Mus NF-kappa B NOS2A gene Nitric Oxide Nitric Oxide Synthase Nucleic Acids Organ Organ failure Organelles Oxidative Phosphorylation Pathway interactions Patients Phenotype Phosphorylation Phosphotransferases Physiological Play Prevalence Prevention Process Production Protein Kinase Proteins Quality Control Receptor Activation Regulation Research Role Sentinel Sepsis Signal Transduction Specificity Standardization Testing Therapeutic Titrations Toll-like receptors Transcriptional Regulation Up-Regulation Work base cost design enzyme activity innovation insight mortality novel novel therapeutic intervention nrf1 protein prevent pro-apoptotic protein programs repaired respiratory response transcription factor

项目摘要

DESCRIPTION (provided by applicant): This revised competitive renewal application seeks to understand how nitric oxide (NO) production in bacterial sepsis causes both mitochondrial damage and regulates mitochondrial quality control, which protects against organ failure. In the previous grant cycle, we discovered that toll-like receptor (TLR) activation of NF-kB- dependent NO synthase (iNOS/NOS2) is involved in the regulation of hepatic mitochondrial biogenesis through the major co-activator, PGC-11 and the adenosine monophosphate (AMP)-activated protein kinase (AMPK). Our preliminary data in mice with sepsis indicate that: NOS2 induction leads to AMPK activation, AMPK helps to activate mitochondrial biogenesis, but not always after ATP depletion, and NOS2 deficiency diminishes AMPK up-regulation and mitochondrial biogenesis and increases apoptosis and inflammation in response to TLR activation. Thus, AMPK appears to activate mitochondrial biogenesis while opposing apoptosis and inflammation in sepsis. In contrast, too much NO is independently associated with mitochondrial damage and loss of NO signal specificity by chemical attack of NO species (NOx) on proteins and nucleic acids. We hypothesize that NOS2, acting in part through AMPK, is required for apposite regulation of the transcriptional program of mitochondrial biogenesis before the failure of ATP production in order to maintain mitochondrial quality control and prevent cell death in sepsis. A test of this hypothesis requires definitions of NO-dependent transcriptional control mechanisms, the role of AMPK, and the chemical biology of mitochondrial NO in relevant model systems. Our approach will focus on the liver as a sentinel organ and on one genetic factor- NOS2- as a quantitative influence on mitochondrial turnover and cell survival. We plan to test these Specific Aims: Aim 1: To determine the role of NOS2 on hepatic mitochondrial biogenesis and cell survival during severe sepsis through quantitative NOS2 gene titration studies. 1A. Define the relationships between NOx-mediated mtDNA and protein damage, respiratory capacity, high-energy metabolite levels, and sepsis-induced hepatic cell death using NOS2 titration. 1B. Assess the importance of NOS2 expression on the regulation of mitochondrial biogenesis in sepsis through CREB and/or NRF-1 induction and regulation of NRF-21 (GABPA) and/or PGC-11 expression. Aim 2: To understand hepatic AMPK activation in sepsis in relation to NOS2, the transcriptional program of mitochondrial biogenesis, and prevention of apoptosis. 2A. Determine if NO-dependent AMPK activation promotes mitochondrial biogenesis in sepsis through CREB and/or prevents apoptosis by inhibitory phosphorylation of pro-apoptotic proteins, Bad and BNIP3. 2B. Determine if pharmacological activation of AMPK in sepsis can promote mitochondrial biogenesis and/or inhibit apoptosis independently of NOS2. These studies will provide new insights into NOx-induced mitochondrial damage in sepsis in the context of physiological mechanisms by which NOS2 regulates mitochondrial biogenesis and the extent to which it is orchestrated by AMPK. By implication, NO regulation of AMPK would play a critical salvage role in MODS, and this knowledge would allow rational new pharmacological approaches to support mitochondrial function while minimizing collateral damage by NOx.

描述（由申请人提供）：本修订后的竞争性更新申请旨在了解细菌性脓毒症中一氧化氮（NO）的产生如何导致线粒体损伤并调节线粒体质量控制，从而防止器官衰竭。在之前的资助周期中，我们发现 Toll 样受体 (TLR) 激活 NF-kB 依赖性 NO 合酶 (iNOS/NOS2) 通过主要辅激活因子 PGC-11 和单磷酸腺苷 (AMP) 激活的蛋白激酶 (AMPK)。我们在脓毒症小鼠中的初步数据表明：NOS2 诱导导致 AMPK 激活，AMPK 有助于激活线粒体生物发生，但并不总是在 ATP 耗尽后，NOS2 缺乏会减少 AMPK 上调和线粒体生物发生，并增加细胞凋亡和炎症反应TLR 激活。因此，AMPK 似乎可以激活线粒体生物合成，同时对抗脓毒症中的细胞凋亡和炎症。相比之下，过多的 NO 与线粒体损伤和 NO 信号特异性丧失（由于 NO 种类 (NOx) 对蛋白质和核酸的化学攻击）独立相关。我们假设 NOS2 部分通过 AMPK 发挥作用，是在 ATP 产生失败之前对线粒体生物发生的转录程序进行适当调节所必需的，以维持线粒体质量控制并防止脓毒症中的细胞死亡。检验这一假设需要定义 NO 依赖性转录控制机制、AMPK 的作用以及相关模型系统中线粒体 NO 的化学生物学。我们的方法将重点关注作为前哨器官的肝脏和一种遗传因子 - NOS2 - 作为对线粒体周转和细胞存活的定量影响。我们计划测试这些具体目标：目标 1：通过定量 NOS2 基因滴定研究确定 NOS2 对严重脓毒症期间肝线粒体生物发生和细胞存活的作用。 1A。使用 NOS2 滴定确定 NOx 介导的 mtDNA 与蛋白质损伤、呼吸能力、高能代谢物水平和脓毒症诱导的肝细胞死亡之间的关系。 1B.通过 CREB 和/或 NRF-1 诱导以及 NRF-21 (GABPA) 和/或 PGC-11 表达的调节，评估 NOS2 表达对脓毒症线粒体生物发生调节的重要性。目标 2：了解脓毒症中肝脏 AMPK 激活与 NOS2、线粒体生物发生的转录程序以及细胞凋亡预防的关系。 2A。确定 NO 依赖性 AMPK 激活是否通过 CREB 促进脓毒症中的线粒体生物合成和/或通过促凋亡蛋白 Bad 和 BNIP3 的抑制性磷酸化来防止细胞凋亡。 2B。确定脓毒症中 AMPK 的药理学激活是否可以独立于 NOS2 促进线粒体生物发生和/或抑制细胞凋亡。这些研究将在 NOS2 调节线粒体生物合成的生理机制及其由 AMPK 协调的程度的背景下，为脓毒症中 NOx 诱导的线粒体损伤提供新的见解。这意味着，NO 对 AMPK 的调节将在 MODS 中发挥关键的挽救作用，这一知识将允许合理的新药理学方法来支持线粒体功能，同时最大限度地减少 NOx 造成的附带损害。