Oxidant stress & ascorbic acid processing in diabetes

氧化应激

• 批准号: 6659258
• 负责人: VINCENT M MONNIER
• 金额: $ 9.46万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6659258
• 关键词: aldehyde reductase; antioxidants; ascorbate; chelating agents; clinical research; diabetes mellitus; diabetic nephropathy; diabetic retinopathy; heavy metals; human tissue; laboratory rat; nuclear magnetic resonance spectroscopy; oxidative stress; pathologic process; vitamin metabolism

Project #2: OXIDANT STRESS AND ASCORBIC ACID PROCESSING IN DIABETES The objective of the Program Project is to investigate the role of oxidative and carbonyl stress in the pathogenesis of diabetic complications. In particular, this project (Project 2) seeks to test the hypothesis that the oxidative stress resulting from high glucose in tissue culture and the diabetic rat is, in contrast to the diabetic human, primarily transition metal and aldose reductase dependent. Furthermore, we hypothesize many of the drugs thought to act as aldose reductase inhibitors, anti-glycating agents, growth factors, NO synthase, PKC and other inhibitors have beneficial effects in the rat as transition metal chelators and/or antioxidants. We propose to test these hypotheses by using a very powerful probe for assessment of oxidative stress in vivo, i.e 6-deoxy-6- fluoro ascorbic acid (F-ascorbate) in conjunction with 750 MHz 19F- NMR-spectroscopy, while at the same time providing the first biochemical insight into ascorbate catabolism in vivo and its modulation by diabetes. 1. To determine the chemical nature and mechanism of formation of F- ascorbate degradation products formed in vitro in low and high glucose environment. 2: To determine how the metabolic pathways of F-ascorbate degradation in cells implicated in diabetic complications are influenced by high glucose environment, and 3. To determine how diabetes in the rat and the human affects ascorbate processing, and whether uncovered abnormalities predict development of diabetic complications in the rat and DCCT patient. Using this novel approach, we expect to clarify the critical question: Is the reason why a large number of drugs have been successful in the diabetic rat but have failed in the human due to normalization of oxidative stress that is specific to the diabetic rat and of such overwhelming intensity that it masks other mechanisms of diabetes induced complications in the human. If confirmed, this outcome would have a profound effect on the future development of anti-diabetic therapies based on the rat model of hyperglycemia.

项目#2：糖尿病中的氧化应激和抗坏血酸加工该计划项目的目的是研究氧化和羰基应激在糖尿病并发症发病机制中的作用。特别是，该项目（项目 2）旨在检验以下假设：与糖尿病人类相比，组织培养物和糖尿病大鼠中高葡萄糖引起的氧化应激主要依赖于过渡金属和醛糖还原酶。此外，我们假设许多被认为充当醛糖还原酶抑制剂、抗糖化剂、生长因子、NO合酶、PKC和其他抑制剂的药物作为过渡金属螯合剂和/或抗氧化剂对大鼠具有有益作用。我们建议通过使用一种非常强大的探针来评估体内氧化应激，即6-脱氧-6-氟抗坏血酸（F-抗坏血酸）与750 MHz 19F-NMR光谱相结合，来测试这些假设，同时提供对体内抗坏血酸分解代谢及其通过糖尿病的调节的第一个生化见解。 1. 确定在低和高葡萄糖环境下体外形成的F-抗坏血酸降解产物的化学性质和形成机制。 2: 确定与糖尿病并发症有关的细胞中 F-抗坏血酸降解的代谢途径如何受到高葡萄糖环境的影响，以及 3. 确定大鼠和人类的糖尿病如何影响抗坏血酸加工，以及未发现的异常是否可以预测大鼠和 DCCT 患者糖尿病并发症的发展。使用这种新方法，我们希望澄清一个关键问题：为什么大量药物在糖尿病大鼠中取得成功，但在人类中却失败了，因为氧化应激正常化是糖尿病大鼠特有的，而且氧化应激的强度如此之大，以至于掩盖了糖尿病引起的人类并发症的其他机制。如果得到证实，这一结果将对基于大鼠高血糖模型的抗糖尿病疗法的未来发展产生深远影响。