Reactive nitrogen species and accelerated atherosclerosis in type I diabetes

I 型糖尿病中的活性氮和加速动脉粥样硬化

基本信息

批准号：
8604403
负责人：
MING-HUI ZOU
金额：
$ 36.26万
依托单位：
UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-09-30 至 2018-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8604403
关键词：
26S proteasome 3-nitrotyrosine Abbreviations Acceleration Active Sites Address Affect Anions Antioxidants Arginine Atherosclerosis Binding Binding Sites Chronic Coupled Crossbreeding Cysteine Data Development Diabetes Mellitus Diabetic mouse Dose Endothelial Cells Endothelium Enzymes Funding GTP Cyclohydrolase I Glucose Goals Guanosine Triphosphate Half-Life Histidine Human Hydrogen Peroxide Hyperglycemia Insulin-Dependent Diabetes Mellitus Ions Kindling (Neurology)Knock-out Knockout Mice L-Glucose Lesion Low Density Lipoprotein Receptor MG132 Maintenance Mass Spectrum Analysis Metabolic stress Modification Molecular Mus Mutation NG-Nitroarginine Methyl Ester Nitric Oxide Oxidants Oxidative Stress Peptide Mapping Peroxonitrite Proteasome Inhibitor Proteins Publishing Reactive Nitrogen Species Reactive Oxygen Species Recombinants Reporting Resistance Role Source Streptozocin Stress Structure Sulfhydryl Compounds Superoxide Dismutase Superoxides Supplementation System Testing Transgenic Mice Transgenic Organisms UCP2 protein Ubiquitin Ubiquitination Uric Acid Zinc arginine methyl ester cofactor effective therapy enzyme activity exposed human population human NOS3 protein in vivo inhibitor/antagonist mouse model multicatalytic endopeptidase complex mutant novel overexpression oxidation prevent protein protein interaction public health relevance tetrahydrobiopterin

项目摘要

DESCRIPTION (provided by applicant): During last funding period, we have found that reactive nitrogen species such as peroxynitrite (ONOO-) uncouples endothelial nitric oxide synthase (eNOS) {generates superoxide anions (O2.-) or ONOO- instead of nitric oxide (NO)} and that eNOS uncoupling in diabetes causes accelerated atherosclerosis. Further, we found that tetrahydrobiopterin (BH4) deficiency, an essential cofactor for eNOS, is the key in the development of eNOS uncoupling in diabetes. Finally, we report that BH4 deficiency is due to rapid degradation of GTP cyclohydrolase I (GTPCH1; E.C. 3.5.4.16), the rate-limiting enzyme in BH4 de novo synthesis, by ubiquitin-proteasome system (UPS) in endothelial cells. However, why GTPCH1 is affected by diabetes hasn't been addressed. Thus, this project will test the hypothesis that oxidation of the zinc-binding structures of GTPCH1 inactivates the enzyme resulting in BH4 deficiency with consequent eNOS uncoupling in diabetes. Aim 1 is establish the essential role of zinc in maintaining GTPCH1 activity and stability and if oxidative disruption of the zinc-cysteine- histidine complexation in GTPCH1 enhances ubiquitination and consequent proteasomal degradation. Aim 2 is to investigate the molecular mechanisms by which hyperglycemia inhibits GTPCH1 in endothelial cells. Aim 3 is to determine the contributions of ONOO--induced GTPCH1 inhibition and ubiquitination in diabetes-enhanced atherosclerosis in mouse models of atherosclerosis in vivo. We believe that the proposed studies will provide novel information as to how the metabolic stress associated with diabetes causes damage to the endothelium and how the endothelial cell attempts to protect itself against these stresses and whether scavenging ONOO- is an effective therapy for diabetes.

描述（由申请人提供）：在上一个资助期间，我们发现活性氮物质如过氧亚硝酸盐（ONOO-）解偶联内皮一氧化氮合酶（eNOS）{生成超氧阴离子（O2.-）或ONOO-而不是一氧化氮(NO)} 并且糖尿病中 eNOS 解偶联会导致动脉粥样硬化加速。此外，我们发现四氢生物蝶呤（BH4）缺乏是 eNOS 的重要辅助因子，是糖尿病中 eNOS 解偶联发展的关键。最后，我们报告 BH4 缺陷是由于内皮细胞中泛素蛋白酶体系统 (UPS) 快速降解 BH4 从头合成的限速酶 GTP 环水解酶 I (GTPCH1；E.C. 3.5.4.16) 造成的。然而，为什么 GTPCH1 会受到糖尿病的影响尚未得到解决。因此，该项目将测试以下假设：GTPCH1 锌结合结构的氧化会使该酶失活，导致 BH4 缺乏，从而导致糖尿病中 eNOS 解偶联。目标 1 是确定锌在维持 GTPCH1 活性和稳定性方面的重要作用，以及 GTPCH1 中锌-半胱氨酸-组氨酸络合的氧化破坏是否会增强泛素化和随后的蛋白酶体降解。目标 2 是研究高血糖抑制内皮细胞中 GTPCH1 的分子机制。目标 3 是确定 ONOO 诱导的 GTPCH1 抑制和泛素化在体内动脉粥样硬化小鼠模型中糖尿病增强的动脉粥样硬化中的作用。我们相信，拟议的研究将提供新的信息，说明与糖尿病相关的代谢应激如何对内皮细胞造成损害，内皮细胞如何试图保护自身免受这些应激，以及清除 ONOO- 是否是糖尿病的有效疗法。