L-2-Hydroxyglutarate and Metabolic Remodeling in Hypoxia

L-2-羟基戊二酸和缺氧中的代谢重塑

• 批准号: 10093718
• 负责人: Joseph Loscalzo
• 金额: $ 69.07万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-20 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10093718
• 关键词: 6-Phosphofructo-2-kinase; Address; Adverse effects; Back; Biochemical; Brain Hypoxia-Ischemia; Buffers; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular system; Cell Hypoxia; Cell physiology; Cells; Citric Acid Cycle; Cultured Cells; Data; Dependence; Echocardiography; Endothelial Cells; Endothelium; Eukaryota; Fructose-2,6-bisphosphatase; Functional disorder; G6PD gene; GPX3 gene; Generations; Genetic; Glucose; Glutathione Disulfide; Glycolysis; Goals; Heart; Heterozygote; Homozygote; Human; Hypoxia; In Vitro; Injury; Ischemia; Knock-out; Lead; Mass Spectrum Analysis; Measures; Mediating; Metabolic; Metabolism; Molecular; Mus; Myocardial; NADH; NADP; NADPH Oxidase; Organ; Oxidases; Oxidation-Reduction; Oxides; Oxidoreductase; Oxygen; Pentosephosphate Pathway; Perfusion; Pharmacology; Preparation; Protein Isoforms; Reaction; Reactive Oxygen Species; Reperfusion Therapy; Role; Small Interfering RNA; Stress; Testing; Time; alpha ketoglutarate; base; cancer cell; cell injury; cofactor; cytotoxicity; experimental study; extracellular; glutathione peroxidase; glutathione peroxidase GPX1; heart function; in vivo; inhibitor/antagonist; inorganic phosphate; insight; metabolomics; mouse model; myocardial hypoxia; normoxia; novel; overexpression; oxidation; preservation; response; small molecule

Project Summary. Adaptive metabolic responses to hypoxia reflect essential evolutionary survival strategies in all eukaryotes. We recently identified a unique metabolite that increases in cardiovascular (CV) cells in response to hypoxia, L-2-hydroxyglutarate (L2HG). This metabolite is derived from α- ketoglutarate, or 2-oxoglutarate (2OG), a key intermediate in the tricarboxylic acid cycle. Once formed from 2OG and NADH, L2HG has no other metabolic fate except to undergo oxidation back to 2OG by the stereospecific dehydrogenase, L2HG dehydrogenase (L2HGDH), suggesting that it accommodates (‘buffers’) the increase in reducing equivalents accompanying hypoxia. L2HG has two other unique actions: it suppresses glycolysis and, as we show here, it increases pentose phosphate pathway (PPP) activity. The central hypothesis of this proposal is that L2HG suppresses glycolysis and enhances PPP activity in CV cells to eliminate reactive oxygen species (ROS), maintain cell redox potential, and preserve cell function in hypoxia. To address this hypothesis, we will focus on three specific aims. First, we will determine the molecular metabolic mechanisms underlying the effects of L2HG on glycolysis and PPP activity. In particular, we will focus on the unique role of a specific phosphofructokinase-2 isoform, PFKFB4, as a key regulatory determinant of increased flux through the PPP in hypoxia. Second, we will determine the effect of this L2HG-induced increased PPP activity in hypoxia on cellular redox potential and intra- and extracellular ROS elimination. Here, we will focus on PPP-derived NADPH and GSH as key cofactors in NADPH oxidase and glutathione peroxidase activities, respectively, in order to enhance elimination of excess ROS. Third, we will study the effects of L2HG in hypoxia or ischemia on cellular and cardiac function, respectively, using unique cellular and genetic murine models. Taken together, these studies should provide insights into the mechanisms by which L2HG promotes metabolic remodeling to preserve cell and cardiac function in oxygen-limited states.

项目总结。对缺氧的适应性代谢反应反映了必要的进化生存