L-2-Hydroxyglutarate and Metabolic Remodeling in Hypoxia

L-2-羟基戊二酸和缺氧中的代谢重塑

基本信息

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
项目类别：
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

项目摘要

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.

项目摘要。对缺氧的适应性代谢反应反映了基本的进化生存。我们最近发现了一种独特的代谢物，可以增加心血管疾病的发生。 (CV) 细胞对缺氧的反应，L-2-羟基戊二酸 (L2HG) 这种代谢物源自 α-。酮戊二酸或 2-酮戊二酸 (2OG)，是三羧酸循环中的关键中间体。从 2OG 和 NADH 开始，L2HG 除了通过 NADH 氧化回 2OG 之外没有其他代谢命运。立体特异性脱氢酶，L2HG 脱氢酶（L2HGDH），表明它适应（‘缓冲’）L2HG 伴随缺氧而减少的当量增加还有另外两个独特之处。作用：它抑制糖酵解，并且正如我们在此所示，它增加磷酸戊糖途径 (PPP) 该提案的中心假设是 L2HG 抑制糖酵解并增强 PPP。 CV 细胞中消除活性氧 (ROS)、维持细胞氧化还原电位并保存的活性为了解决这一假设，我们将重点关注三个具体目标。确定 L2HG 对糖酵解和 PPP 影响的分子代谢机制特别是，我们将重点关注特定磷酸果糖激酶-2亚型的独特作用， PFKFB4，作为缺氧时通过 PPP 通量增加的关键调节决定因素。确定缺氧时 L2HG 诱导的 PPP 活性增加对细胞氧化还原电位的影响在这里，我们将重点关注 PPP 衍生的 NADPH 和 GSH。 NADPH氧化酶和谷胱甘肽过氧化物酶活性的关键辅助因子，分别，以增强第三，我们将研究L2HG在缺氧或缺血时对细胞和细胞的影响。分别使用独特的细胞和遗传小鼠模型来研究心脏功能。研究应该深入了解 L2HG 促进代谢重塑的机制在缺氧状态下保持细胞和心脏功能。