Respiration in Sepsis

脓毒症时的呼吸

基本信息

批准号：
8666533
负责人：
CLAUDE A PIANTADOSI
金额：
--
依托单位：
DURHAM VA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-01-01 至 2016-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8666533
关键词：
5&apos -AMP-activated protein kinase AMP-activated protein kinase kinase Adenosine Monophosphate Aging Agonist Animal Model Antibiotics Apoptosis Apoptotic Area Autophagocytosis Basic Science Biogenesis CREB1 gene Carbon Monoxide Caring Cause of Death Cell Death Cell Survival Cell model Chemical Warfare Data Disease Energy Metabolism Event Failure Funding Gene Expression Regulation Genes Genetic Genetic Programming Goals Health Hepatic Hepatocyte High Prevalence Hypoxia Immune system Infection Inflammation Inflammatory Lead Life Link Liver Mediating Mediator of activation protein Mitochondria Mitochondrial DNA Mitochondrial Proteins Molecular Multiple Organ Failure Mus Nitric Oxide Nitric Oxide Synthase Organ Oxidation-Reduction Pathogenesis Pathway interactions Phosphorylation Prevention Process Production Protein Kinase Proteins Quality Control Receptor Activation Regulation Respiration Role Sentinel Sepsis Signal Transduction Specificity Standardization Staphylococcus aureus Syndrome Testing Therapeutic Thinking Tissues Titrations Toll-like receptors Transcription factor genes Transcriptional Regulation Up-Regulation Veterans Work cell injury cost design high throughput screening innovation insight mortality novel nrf1 protein prevent programs public health relevance respiratory response transcription factor

项目摘要

DESCRIPTION (provided by applicant): This VA Merit Review renewal application proposes to study transcriptional regulation of the pro-survival program of mitochondrial biogenesis during experimental S. aureus sepsis. The need for basic research in this area is high due to the high prevalence and cost of sepsis-induced multiple organ dysfunction syndrome (MODS) in older Veterans. This high mortality syndrome is due in part to mitochondrial damage, which is mechanistically poorly understood. Using earlier funding, we discovered that mitochondrial biogenesis in sepsis is activated before energy crisis, while a rescue pathway is delayed involving the adenosine monophosphate (AMP)-activated protein kinase (AMPK) and PGC-1¿ co-activator. New preliminary data links AMPK activation to nitric oxide synthase-2 (NOS2) induction in sepsis, does not require high AMP/ATP, and loss of AMPK activation in nitric oxide synthase-2 (NOS2) deficient mice is accompanied by worsening inflammation. AMPK may serve as an activator of three crucial transcription factors- CREB, NRF-1, and NRF- 2 (GABPA) for mitochondrial biogenesis in sepsis, but NO regulation also induces mitochondrial damage by loss of NO signal specificity and indiscriminate chemical attack on mitochondria by NO species (NOx). We propose that AMPK activation by impending energy failure up-regulates the mitochondrial damage control program in sepsis and if so, NO-independent pharmacological AMPK activation could control excess NO production and mitigate sepsis-induced MODS. We will focus on AMPK in the liver, a sentinel organ, and NOS2 as a quantitative influence on mitochondrial turnover and apoptosis using pharmacological AMPK activation to limit NO-induced mitochondrial damage. Our Specific Aims are: Aim 1: To understand hepatic AMPK activation in sepsis in relation to NOS2 induction, the program of mitochondrial biogenesis, and the prevention of apoptosis. 1A. Define the relationships between AMPK activation and NOx-mediated mtDNA and protein damage, respiratory capacity, high-energy metabolites, and sepsis-induced hepatic cell death using NOS2 gene titration. 1B. Determine if AMPK activation through NO-dependent CREB/NRF-1 activity promotes mitochondrial biogenesis and inhibitory phosphorylation of pro-apoptotic Bad and BNIP3, preventing apoptosis in sepsis. Aim 2: To determine if specific strategies to activate or inhibit AMPK independently of NOS2 regulate hepatic mitochondrial biogenesis and cell survival and lessen NO-dependent cell damage in sepsis. 2A. Determine if the pharmacological activation of AMPK independently of NOS2 promotes mitochondrial biogenesis and/or inhibits apoptosis in sepsis. We will also use high-throughput screening to identify one or more novel selective agonists of AMPK. 2B. Compare NO-dependent and NO-independent AMPK activation for effects on the transcriptional regulation of mitochondrial biogenesis in sepsis using CREB and PGC-1¿ as key readouts. These studies will provide new molecular data on AMPK regulation of mitochondrial biogenesis in sepsis, and on the extent to which NO production is regulatory. Proof-of-concept would lead to rational pharmacological approaches to activate and support mitochondrial biogenesis while minimizing NO-induced collateral damage. Understanding these fundamental regulatory mechanisms is needed to design forward-thinking therapeutic approaches to protect mitochondrial quality control during sepsis.

描述（由申请人提供）：该 VA 优异评审更新申请提出研究实验性金黄色葡萄球菌脓毒症期间线粒体生物发生的促生存程序的转录调控。由于脓毒症引起的多器官的高患病率和成本，该领域的基础研究需求很高。老年退伍军人的功能障碍综合症（MODS）部分是由于线粒体损伤造成的，而人们对线粒体损伤的机制知之甚少。利用早期的资金，我们发现脓毒症中的线粒体生物发生在能源危机之前被激活，而救援。涉及单磷酸腺苷 (AMP) 激活蛋白激酶 (AMPK) 和 PGC-1¿新的初步数据将 AMPK 激活与脓毒症中一氧化氮合酶 2 (NOS2) 的诱导联系起来，不需要高 AMP/ATP，并且一氧化氮合酶 2 (NOS2) 缺陷小鼠中 AMPK 激活的丧失伴随着AMPK 可能是脓毒症线粒体生物合成中三种关键转录因子 CREB、NRF-1 和 NRF-2 (GABPA) 的激活剂，但NO 调节还通过 NO 信号特异性的丧失和 NO 种类 (NOx) 对线粒体的不加区别的化学攻击来诱导线粒体损伤。独立的药理学 AMPK 激活可以控制过量的 NO 产生并减轻脓毒症引起的 MODS。我们将重点关注肝脏（前哨器官）中的 AMPK 和 NOS2，利用药理学对线粒体周转和细胞凋亡进行定量影响。 AMPK 激活以限制 NO 诱导的线粒体损伤：目标 1：了解脓毒症中肝脏 AMPK 激活与 NOS2 诱导、线粒体生物发生程序和细胞凋亡预防之间的关系。使用 NOS2 基因滴定确定激活和 NOx 介导的 mtDNA 和蛋白质损伤、呼吸能力、高能代谢物和脓毒症诱导的肝细胞死亡。 AMPK 通过 NO 依赖性 CREB/NRF-1 活性激活，促进线粒体生物发生和促凋亡 Bad 和 BNIP3 的抑制性磷酸化，防止脓毒症中的细胞凋亡。目标 2：确定独立于 NOS2 激活或抑制 AMPK 的特定策略是否调节肝线粒体。脓毒症中的生物发生和细胞存活以及较少的 NO 依赖性细胞损伤确定 AMPK 的药理学激活是否独立于 NOS2 促进线粒体生物发生。我们还将使用高通量筛选来鉴定 AMPK 2B 的一种或多种新型选择性激动剂，以比较 NO 依赖性和 NO 依赖性 AMPK 激活对脓毒症中线粒体生物合成的转录调节的影响。使用 CREB 和 PGC-1¿这些研究将提供有关脓毒症中 AMPK 调节线粒体生物发生的新分子数据，以及 NO 产生的调节程度的概念验证将导致合理的药理学方法来激活和支持线粒体生物发生，同时最大限度地减少线粒体生物发生。需要了解 NO 引起的附带损伤，以设计前瞻性的治疗方法来保护脓毒症期间的线粒体质量控制。