CRITICAL TARGETS IN HYPEROXIC MITOCHONDRIAL INJURY

高氧线粒体损伤的关键目标

• 批准号: 7716163
• 负责人: Carl W White
• 金额: $ 2.26万
• 依托单位: TEXAS BIOMEDICAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7716163
• 关键词: Aconitate Hydratase; Adenine Nucleotides; Adult; Antioxidants; Binding; Biochemical; Biological Assay; Bronchopulmonary Dysplasia; Cell Respiration; Chronic lung disease; Complex; Computer Retrieval of Information on Scientific Projects Database; Continuous Infusion; Electron Microscopy; Environmental air flow; Enzymes; Exposure to; Funding; Glutamine; Glutathione; Glycolysis; Grant; Histopathology; Hyperoxia; Injury; Institution; Lung; Measures; Mitochondria; Modeling; Newborn Infant; Oxidants; Oxidative Stress; Oxygen; Papio; Premature Birth; Proteins; Rate; Rattus; Research; Research Personnel; Resources; Respiratory distress; S-Adenosylmethionine; Source; Stress; Sulfur Amino Acids; Superoxide Dismutase; Supplementation; TXN gene; Testing; Thioredoxin; Transcriptional Activation; United States National Institutes of Health; Up-Regulation; Voltage-Dependent Anion Channel; base; hexokinase; porin

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Bronchopulmonary dysplasia (BPD) is a common, disabling and sometimes fatal chronic lung disease. It frequently accompanies premature birth and treatment of respiratory distress with artificial ventilation and high concentrations of inspired oxygen (hyperoxia). The biochemical basis of BPD is not well understood. In the baboon, exposure to hyperoxia is required treatment in both the ultra-premature (125 d) and premature (140) model of BPD. Hyperoxia damages mitochondria results in loss of aconitase activity, decreased mitochondrial and cell respiration, and loss of ATP. On that basis, this proposal's principal hypothesis is that adaptation to hyperoxic stress requires up-regulation of glycolytic, and/or glutaminolytic, enzymes. Because hexokinase rate- limits glycolysis in lung, it is hypothesized that expression of lung hexokinase(s) is up-regulated. Replacement of deficient mitochondrial anti-oxidants may alleviate early respiratory distress and resulting BPD and decrease up regulation of glycolytic enzymes. These hypotheses will be tested in these AIMS; 1) Determine differential expression of mRNA's encoding components of the mitochondrial porin complex-hexokinases (HKs), porins, and adenine nucleotide translocators (ANT), these same proteins, and relevant glycolytic and glutaminolytic enzymes; 2) Define early status of critical anti-oxidants (glutathione [GSH], thioredoxin [TRX], superoxide dismutases]), their precursors (S-adenosylmethionine), and oxidant target (aconitase) markers, and (3) Define the efficacy of early, continuous infusion of S-adenosylmethionine (AdoMet), a precursor of cellular and mitochondrial glutathione (GSH), on these markers and pulmonary histopathology of BPD. Hexokinase binding to, or release from, mitochondria will be quantitied using immunogold electron microscopy. Activities of HK, phosphofructokinase, and additional critical glycolytic and glutaminolytic enzymes also will be assayed. Lung GSH, TRX, and AdoMet, as well as circulating GSH, AdoMet, and sulfur amino acids will be measured early in the 125 d model. Together, these approaches will help define whether changes in hexokinase activity expression, known to occur in lungs of adult rats made oxygen-tolerant, also occur in the premature newborn baboon. In addition, they will indicate whether or not increased expression of pulmonary glutamine- utilizing enzymes also occurs during pulmonary oxidative stress and whether anti-oxidant stress and whether anti-oxidant supplementation modifies these adaptations.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 支气管肺发育不良 (BPD) 是一种常见、致残、有时甚至致命的慢性肺部疾病。它经常伴随着早产和通过人工通气和高浓度吸入氧（高氧）治疗呼吸窘迫。 BPD 的生化基础尚不清楚。对于狒狒，BPD 的超早产（125 天）和早产（140 天）模型都需要接受高氧治疗。高氧会损害线粒体，导致乌头酸酶活性丧失、线粒体和细胞呼吸减少以及 ATP 损失。在此基础上，该提议的主要假设是适应高氧应激需要上调糖酵解和/或谷氨酰胺分解酶。由于己糖激酶速率限制肺中的糖酵解，因此推测肺己糖激酶的表达上调。替代缺乏的线粒体抗氧化剂可以缓解早期呼吸窘迫和由此导致的 BPD，并减少糖酵解酶的上调。这些假设将在这些 AIMS 中得到检验； 1) 确定线粒体孔蛋白复合物-己糖激酶（HK）、孔蛋白和腺嘌呤核苷酸易位子（ANT）的mRNA编码成分、这些相同的蛋白质以及相关的糖酵解和谷氨酰胺分解酶的差异表达； 2) 确定关键抗氧化剂（谷胱甘肽 [GSH]、硫氧还蛋白 [TRX]、超氧化物歧化酶]）、其前体（S-腺苷甲硫氨酸）和氧化靶标（乌头酸酶）标记物的早期状态，以及 (3) 确定早期持续输注 S-腺苷甲硫氨酸 (AdoMet) 的功效，S-腺苷甲硫氨酸 (AdoMet) 是细胞和细胞因子的前体。 线粒体谷胱甘肽 (GSH)，这些标记物和 BPD 的肺组织病理学。使用免疫金电子显微镜对与线粒体结合或从线粒体释放的己糖激酶进行定量。 HK、磷酸果糖激酶以及其他关键糖酵解和谷氨酰胺分解酶的活性也将进行测定。肺 GSH、TRX 和 AdoMet 以及循环 GSH、AdoMet 和硫氨基酸将在 125 天模型的早期进行测量。总之，这些方法将有助于确定已知成年大鼠肺部发生的耐氧性己糖激酶活性表达的变化是否也发生在早产新生狒狒身上。此外，他们还将表明肺氧化应激期间是否也会出现肺谷氨酰胺利用酶表达的增加，以及抗氧化应激和抗氧化剂补充剂是否会改变这些适应。