GPx-3 and Peroxide Flux in the Endothelial Cell

内皮细胞中的 GPx-3 和过氧化物通量

基本信息

批准号：
7463615
负责人：
Joseph Loscalzo
金额：
$ 43.75万
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：
1998
资助国家：
美国
起止时间：
1998-09-30 至 2012-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7463615
关键词：
AQP1 gene Affect Alcohols Anions Antioxidants Award Binding Biochemistry Biological Biological Assay Biological Availability Blood Platelets Blood Vessels Catabolism Cell Line Cell Membrane Permeability Cell Respiration Cell membrane Cell surface Cells Cellular biology Cloning Complementary DNA Complex Condition Coupled Cytokine Activation Cytosol Disulfides Endothelial Cells Environment Enzymes Epidermal Growth Factor Epidermal Growth Factor Receptor Erythropoietin Event Extracellular Space Fibroblasts Gene Expression Generations Genes Genetic Transcription Glutathione Growth Half-Life Haplotypes Hematopoietic Cell Growth Factors Heparitin Sulfate Hydrogen Hydrogen Peroxide Hypoxia Individual Insulin Kidney Kinetics Laboratories Lead Length Ligand Binding Ligands Lipid Peroxides Lipids Luciferases Measures Mediating Membrane Messenger RNA Metabolic Metabolism Mitochondria Molecular Molecular Weight Monitor Mus NADPH Oxidase Nitric Oxide Nitric Oxide Synthase Oxidants Oxidation-Reduction Oxygen Peroxidase Peroxidases Peroxides Personal Satisfaction Phosphorylation Plants Plasma Platelet Activation Principal Investigator Process Production Protein Overexpression Proteins Proteomics Range Reactive Oxygen Species Reading Receptor Signaling Receptors, Adrenergic, beta-1 Recombinants Recycling Reducing Agents Regulation Reporter Research Personnel Respiration Response Elements Rest Risk Role SOD2 gene Selenium Selenocysteine Signal Transduction Signaling Molecule Small Interfering RNA Smooth Muscle Myocytes Source Stress Superoxide Dismutase Superoxides System Testing Thioredoxin Thrombotic Stroke Transcription Initiation Site Transfection Translations Transmembrane Transport Water Work Xanthine Oxidase Xanthines catalase chromatin immunoprecipitation cofactor cytokine cytotoxicity disulfide bond enzyme activity enzyme substrate extracellular glutaredoxin glutathione peroxidase in vivo insight member network models peroxisome polysulfated glycosaminoglycan programs promoter protein expression receptor receptor function research study response selenoprotein small molecule thioredoxin reductase transcription factor water channel xanthine

项目摘要

DESCRIPTION (provided by applicant): Cellular oxidative metabolism leads to the generation of reactive oxygen species (ROS). Antioxidant mechanisms have evolved to regulate the steady-state flux of ROS and minimize their cytotoxicity. The antioxidant potential of cells is largely governed by both low-molecular-weight reductants and by antioxidant enzymes. While the intracellular determinants of ROS flux by vascular cells have been well characterized in recent years, the extracellular determinants of ROS flux and their regulation are less well understood. For the last two cycles of this award, we have studied a key antioxidant enzyme that regulates extracellular peroxide flux, glutathione peroxidase-3 (GPx-3). We studied the biochemistry and molecular cell biology of this selenoprotein in order to understand its role in regulating the bioavailability of endothelial nitric oxide and in modulating platelet activation in the vasculature. While GPx-3 can effectively reduce both hydrogen peroxide and lipid peroxides to water and lipid alcohols, respectively, recent kinetic studies suggest that hydrogen peroxide is the preferred substrate. Because extracellular hydrogen peroxide can affect endothelial cell-surface receptor signaling (at low concentrations) and extracellular oxidant stress (at high concentrations), the factors that govern its production, molecular actions, and metabolic fates in the vasculature warrant study. The central hypothesis of this proposal is that GPx-3 is a principal determinant of extracellular hydrogen peroxide flux from the endothelial cell, and a key regulator of the transmembrane cycling and actions of hydrogen peroxide in the endothelial cell. To test this hypothesis, we propose three specific aims. We will first assess the role of GPx-3 in eliminating hydrogen peroxide and will examine the reductive cofactor(s) required for its optimal activity in the extracellular microenvironment of the endothelial cell. Second, we will determine the role of hydrogen peroxide in regulating the expression of GPx-3 at the transcriptional, posttranscriptional, and translational levels. Third, we will examine the interactions between GPx-3 and its intracellular counterpart GPx-1 on the transcellular metabolism and cycling of hydrogen peroxide, and its consequences for "outside-in" and "inside-out" signaling in endothelial cells. These studies should provide insight into the complex relationships among hydrogen peroxide flux, extracellular antioxidant potential, and cell signaling and oxidant stress in the endothelial cell.

描述（由申请人提供）：细胞氧化代谢导致活性氧（ROS）的产生。抗氧化剂机制已演变为调节ROS的稳态通量并最大程度地减少其细胞毒性。细胞的抗氧化潜力在很大程度上受低分子量还原剂和抗氧化剂酶的控制。尽管近年来，血管细胞的ROS通量的细胞内决定因素已得到很好的特征，但ROS通量的细胞外决定因素及其调节的理解较少。在该奖项的最后两个周期中，我们研究了一种关键的抗氧化剂酶，该酶调节细胞外过氧化物通量，谷胱甘肽过氧化物酶-3（GPX-3）。我们研究了该硒蛋白的生物化学和分子细胞生物学，以了解其在调节内皮一氧化氮的生物利用度以及调节血管中血小板激活方面的作用。虽然GPX-3可以有效地将过氧化氢和脂质过氧化氢降低到水和脂肪醇中，但最近的动力学研究表明，过氧化氢是首选的底物。因为细胞外氢过氧化氢可以影响内皮细胞表面受体信号传导（低浓度下）和细胞外氧化剂应激（在高浓度下），所以在脉管保证书中控制其产生，分子作用和代谢命运的因素。该提案的中心假设是GPX-3是内皮细胞中细胞外氢通量的主要决定因素，并且是跨膜循环和过氧化氢在内皮细胞中的关键调节剂。为了检验这一假设，我们提出了三个具体目标。我们将首先评估GPX-3在消除过氧化氢中的作用，并将检查其在内皮细胞的细胞外微环境中其最佳活性所需的还原性辅因子。其次，我们将确定过氧化氢在转录，转录后和翻译水平上调节GPX-3的表达中的作用。第三，我们将检查GPX-3及其细胞内的GPX-1之间的相互作用在细胞代谢和过氧化氢的循环上，以及其对内皮细胞中“外部”和“内部”信号传导的影响。这些研究应洞悉过氧化氢通量，细胞外抗氧化剂电位以及内皮细胞中细胞信号传导和氧化剂应激之间的复杂关系。