Effect of Sepsis on Cytochrome aa3 Oxidation State

脓毒症对细胞色素aa3氧化态的影响

• 批准号: 9475831
• 负责人: Robert H Thiele
• 金额: $ 18.83万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9475831
• 关键词: Anaerobic Bacteria; Antibiotics; Attenuated; Biogenesis; Biological Sciences; Biomedical Engineering; Carbon Monoxide; Cause of Death; Cell Respiration; Centers for Disease Control and Prevention (U.S.); Cessation of life; Clinical; Complex; Cytochromes; Depressed mood; Development; Disease; Dose; Down-Regulation; Electron Transport; Elements; Equilibrium; Foundations; Generations; Genetic Transcription; Heme aa3 Cytochrome Oxidase; Hyperbaric Oxygen; Hypoxia; Immunocompetence; Immunologics; Incidence; Inflammation; Inflammation Mediators; Intestines; Ischemia; Ischemic Preconditioning; K-Series Research Career Programs; Lead; Lymphocyte; Maintenance; Mammals; Measures; Mediating; Messenger RNA; Metabolic; Metabolism; Mitochondria; Modality; Modeling; Monitor; Morbidity - disease rate; Mus; Nitric Oxide; Nitric Oxide Synthase; Nuclear; Organ; Organism; Oxidation-Reduction; Oxidative Stress; Oxides; Oxygen; Pathology; Patient risk; Pharmacology; Play; Preparation; Process; Production; Protein Isoforms; Puncture procedure; Randomized; Rattus; Reactive Nitrogen Species; Reactive Oxygen Species; Recovery; Reperfusion Therapy; Research Personnel; Resuscitation; Rodent Model; Role; Sepsis; Source; T-Lymphocyte; Time; Tissues; Training; United States; Up-Regulation; Vascular Endothelial Growth Factors; Work; bactericide; career; cecal ligation puncture; cytokine; efficacy testing; falls; heme oxygenase-1; high risk; hypoxia inducible factor 1; improved; insight; knock-down; mitochondrial dysfunction; mitochondrial metabolism; mortality; novel; novel therapeutic intervention; novel therapeutics; nuclear factor 1; oxidation; preconditioning; public health relevance; response; septic; treatment strategy

 DESCRIPTION (provided by applicant): This is an application for a career development award to provide the PI with training in integrative biosciences and biomedical engineering in preparation for a career as an independent investigator focused on the impact of inflammopathies (e.g. sepsis) on subcellular energetics. Sepsis leads to ATP depletion and cytochrome aa3 (terminal component of the electron transport chain) reduction. The PI will investigate the impact of uncontrolled sepsis (rat cecal ligation and puncture) and established sepsis therapies on cytochrome aa3 oxidation state (Cytox), tissue pO2, ATP:ADP ratio, and survival in order to better understand the impact of this observed energetic "quiescence" (SA1). I hypothesize that this "quiescence" is adaptive and that inability to shut down metabolism will be associated with morbidity. The role of tissue O2 in inflammation is not clear. O2 can be both helpful (allowing for aerobic respiration) and harmful (reactive oxygen species [ROS] production). The PI will alter tissue O2 with/without selective cytochrome aa3 inhibition in septic rats while measuring tissue pO2, Cytox, markers of oxidative stress, ATP:ADP ratios, hypoxia-induced factor 1(HIF-1) expression, and survival to determine if tissue O2 is protective during inflammation, as well as elucidate the underlying mechanism(s) for its impact (SA2). I hypothesize sepsis-induced quiescence diminishes the impact of low tissue pO2, and that supranormal tissue pO2 leads to ROS production and morbidity. Preconditioning (PC) provides cellular protection in a variety of pathologies. While pharmacologic PC is protective in sepsis, it is clinically impractical, thus the PI will test the efficacy of hypoxic and ischemic PC as a protective mechanism. After a brief period of controlled hypoxia or remote ischemic preconditioning (RIPC), sepsis will be induced in rats. Cytox, expression of HIF-1, heme-oxygenase-1 (HO-1), inducible nitric oxide synthetase, and survival will be measured (SA3). I hypothesize that RIPC will lead HIF-1 upregulation, attenuating ROS production. Demonstration of efficacy would suggest a practical means of "pre-empting" sepsis in high-risk patients. HIF-1 attenuates ROS production and induces mitochondrial biogenesis (via HO-1) which are likely prosurvival for the organism but may limit T cell efficacy (ROS are bactericidal). The impact of HIF-1 downregulation on the balance of cellular energetics and immunocompetence is not clear. The PI will compare sepsis tolerance in wild-type and "knockdown" mice deficient in the HIF-1 I.1 isoform, specifically looking at HIF-1 expression, Cytox, oxidative stress, and survival (SA4). While HIF-1 suppression in lymphocytes improves survival in sepsis (by increasing antibactericidal activity), I hypothesize that global HIF-1 downregulation will increase mortality due to overproduction of harmful ROS. Completion of these Specific Aims will increase our understanding of the impact of sepsis on cytochrome aa3 oxidation state, subcellular energetics, and HIF-1, ultimately providing a foundation for additional work to develop novel therapeutic strategies for this devastating disease process.

 描述（由申请人提供）：这是一份职业发展奖的申请，旨在为PI提供综合生物科学和生物医学工程方面的培训，为作为一名独立研究者的职业生涯做准备，该研究者专注于炎症（例如败血症）对亚细胞能量学的影响。脓毒症导致ATP耗竭和细胞色素aa 3（电子传递链的末端组分）还原。PI将研究不受控制的脓毒症（大鼠盲肠结扎和穿孔）和已确立的脓毒症治疗对细胞色素aa 3氧化态（Cytox）、组织pO 2、ATP：ADP比值和存活率的影响，以更好地了解观察到的能量“静止”（SA 1）的影响。我假设这种“静止”是适应性的，无法关闭新陈代谢将与发病率有关。组织O2在炎症中的作用尚不清楚。O2可以是有益的（允许有氧呼吸）和有害的（活性氧[ROS]产生）。在脓毒症中，PI将改变组织O2，伴/不伴选择性细胞色素aa 3抑制 大鼠，同时测量组织pO 2、Cytox、氧化应激标志物、ATP：ADP比率、缺氧诱导因子1（HIF-1）表达和存活率，以确定组织O2在炎症期间是否具有保护作用，并阐明其影响的潜在机制（SA 2）。我假设脓毒症诱导的静止减少了低组织pO 2的影响，并且超正常组织pO 2导致ROS产生和发病。预处理（PC）在多种病理中提供细胞保护。虽然药物PC在脓毒症中具有保护作用，但它 临床上不切实际，因此PI将测试缺氧和缺血PC作为保护机制的有效性。在短暂的控制性缺氧或远程缺血预处理（RIPC）后，将在大鼠中诱导脓毒症。将测量Cytox、HIF-1、血红素加氧酶-1（HO-1）、诱导型一氧化氮合成酶的表达和存活率（SA 3）。我推测RIPC将导致HIF-1上调，减少ROS的产生。有效性的证明将表明在高危患者中“预防”脓毒症的实用方法。HIF-1减弱ROS产生并诱导线粒体生物发生（通过HO-1），这可能是生物体的促生存，但可能限制T细胞功效（ROS是杀菌的）。HIF-1下调对细胞能量平衡和免疫活性的影响尚不清楚。PI将比较野生型和HIF-11.1同种型缺陷的“敲减”小鼠中的脓毒症耐受性，特别是观察HIF-1表达、Cytox、氧化应激和存活（SA 4）。 虽然淋巴细胞中的HIF-1抑制可提高脓毒症患者的生存率（通过增加抗杀菌活性），但我推测，由于有害ROS的过度产生，HIF-1的全面下调将增加死亡率。这些特定目标的完成将增加我们对脓毒症对细胞色素aa 3氧化态，亚细胞能量学和HIF-1的影响的理解，最终为进一步的工作提供基础，为这种毁灭性的疾病过程开发新的治疗策略。