Respiration in Sepsis

脓毒症时的呼吸

• 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
• 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' -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

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议研究实验性金黄色葡萄球菌败血症期间线粒体生物发生的促生存程序的转录调节。由于脓毒症引起的多器官功能障碍综合征（MODS）在老年退伍军人中的患病率和费用都很高，因此该领域的基础研究需求很高。这种高死亡率综合症的部分原因是线粒体损伤，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，而涉及单磷酸腺苷 (AMP) 激活蛋白激酶 (AMPK) 和 PGC-1¿ 共激活剂的救援途径被延迟。新的初步数据将脓毒症中的 AMPK 激活与一氧化氮合酶 2 (NOS2) 诱导联系起来，不需要高 AMP/ATP，一氧化氮合酶 2 (NOS2) 缺陷小鼠中 AMPK 激活的丧失伴随着炎症的恶化。 AMPK 可能作为脓毒症线粒体生物发生中三个关键转录因子 CREB、NRF-1 和 NRF-2 (GABPA) 的激活剂，但 NO 调节也会通过 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而诱导线粒体损伤。我们认为，即将到来的能量衰竭导致的 AMPK 激活上调了脓毒症中的线粒体损伤控制程序，如果是这样，则不依赖于 NO 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，通过药理学 AMPK 激活来限制 NO 诱导的线粒体损伤，从而对线粒体周转和细胞凋亡产生定量影响。我们的具体目标是： 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的关系。 1A。使用 NOS2 基因滴定定义 AMPK 激活与 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之间的关系。 1B.确定 AMPK 通过 NO 依赖性 CREB/NRF-1 活性激活是否会促进线粒体生物发生以及促凋亡 Bad 和 BNIP3 的抑制性磷酸化，从而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 的具体策略是否可以调节肝线粒体生物合成和细胞存活，并减少脓毒症中 NO 依赖性细胞损伤。 2A。确定 AMPK 的药理激活是否独立于 NOS2 促进败血症中的线粒体生物发生和/或抑制细胞凋亡。我们还将使用高通量筛选来鉴定一种或多种新型 AMPK 选择性激动剂。 2B。使用 CREB ​​和 PGC-1¿ 作为关键读数，比较 NO 依赖性和 NO 独立性 AMPK 激活对脓毒症线粒体生物发生转录调节的影响。 这些研究将为脓毒症中 AMPK 调节线粒体生物发生以及 NO 产生的调节程度提供新的分子数据。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 NO 引起的附带损害。 了解这些基本调节机制需要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。