Maillard Reactions and Oxidation in Cataractogenesis

白内障发生中的美拉德反应和氧化

• 批准号: 8428198
• 负责人: Ram H Nagaraj
• 金额: $ 7.6万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8428198
• 关键词: Address; Advanced Glycosylation End Products; Aging; Amino Acids; Apoptosis; Ascorbic Acid; Biochemical; Biochemical Pathway; Biological Assay; Cataract; Cell Survival; Cells; Chemicals; Crystallins; Data; Enzyme Inhibition; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Enzymes; Epithelial Cells; Generations; Glutathione; Homeostasis; Human; Hyperglycemia; In Vitro; Knockout Mice; Kynurenine; Laboratories; Lactoylglutathione Lyase; Lead; Link; Maillard Reaction; Mediating; Metabolic; Methods; Modification; Monoclonal Antibodies; Oxidative Stress; Pathway interactions; Physiology; Pigmentation physiologic function; Pigments; Pilot Projects; Play; Post-Translational Protein Processing; Process; Production; Proteins; Pyruvaldehyde; Reaction; Research; Research Personnel; Role; Small Interfering RNA; Stress; Structure; Tissues; Transgenic Animals; Transgenic Mice; Tryptophan; Tryptophan 2,3 Dioxygenase; Tryptophan Metabolism Pathway; Work; ascorbate; base; crosslink; experience; fiber cell; insight; interest; knockout animal; lens; lens protein; link protein; nitrosative stress; novel; oxidation; programs; protein crosslink; research study; sugar

DESCRIPTION (provided by applicant): Lens proteins undergo numerous physico-chemical changes during aging and cataract formation; pigmentation and crosslinking are the two major ones. Although several biochemical pathways participate in these changes, the actual mechanisms and their interrelationships remain unclear. Our project addresses this very issue. Reactions of dicarbonyl compounds with proteins appear to be major contributors to pigmentation and crosslinking in lens proteins. Recent studies, including our own, point to yet another mechanism for producing these changes, involving kynurenines, tryptophan oxidation products that react with lens proteins to generate pigments and crosslinking structures. Our preliminary data suggest that the dicarbonyl and kynurenine protein modification processes are related and interdependent. Although most reactions in these pathways are non-enzymatic, the reactive compounds formed can initiate further reactions that are regulated by enzymatic mechanisms. We will investigate these mechanisms in the context of lens physiology. Our proposed research is organized to achieve four specific aims. In the first aim, we will focus on methylglyoxal (MGO), a highly reactive dicarbonyl compound in the lens. We will determine how MGO is metabolized by glyoxalase I as well as the importance of glyoxalase I for survival of lens epithelial cells under conditions of hyperglycemic, oxidative or nitrosative stress. In aim 2, we will establish the role of the dideoxyosone (DDO) pathway in lens protein modification. We will determine how this recently discovered pathway, through which sugars and ascorbic acid modify proteins, contributes to lens aging and cataract formation. In aim 3, we will study kynurenine-mediated protein modification. We will focus mainly on indoleamine 2,3-dioxygenase (IDO), an enzyme that catalyzes metabolism of tryptophan to kynurenines. We will use transgenic and knockout mice to investigate the role of IDO in lens protein modification, and explore the effect of hyperglycemia and oxidative stress on IDO activity. Kynurenine-mediated damage to lens proteins will be assessed by chromatographic methods and immunological assays with highly specific monoclonal antibodies. Finally, in aim 4, we will determine the relationship among kynurenines, MGO and DDO in lens protein modifications. Cummulative information gained from these experiments will provide us with critical insights into the biochemical mechanisms that underlie lens aging and cataract formation.

描述（由申请方提供）：透镜蛋白在老化和白内障形成过程中经历许多物理化学变化;色素沉着和交联是两个主要变化。虽然有几种生化途径参与这些变化，但实际机制及其相互关系仍不清楚。我们的项目正是针对这个问题。二羰基化合物与蛋白质的反应似乎是透镜蛋白质中色素沉着和交联的主要贡献者。最近的研究，包括我们自己的研究，指出了产生这些变化的另一种机制，涉及犬尿氨酸，色氨酸氧化产物，与透镜蛋白反应产生色素和交联结构。我们的初步数据表明，二羰基和犬尿氨酸蛋白质修饰过程是相关和相互依赖的。虽然这些途径中的大多数反应是非酶促的，但形成的反应性化合物可以引发由酶促机制调节的进一步反应。我们将在透镜生理学的背景下研究这些机制。我们的研究旨在实现四个具体目标。在第一个目标中，我们将专注于甲基乙二醛（MGO），一种在透镜中具有高度反应性的二羰基化合物。我们将确定MGO是如何代谢的glycoprotein酶I以及glycoprotein酶I的重要性，透镜上皮细胞的生存条件下的高血糖，氧化或亚硝化应激。在目标2中，我们将建立双脱氧核糖酮（DDO）途径在透镜蛋白质修饰中的作用。我们将确定这一最近发现的途径，通过糖和抗坏血酸修饰蛋白质，有助于透镜老化和白内障的形成。在目标3中，我们将研究犬尿氨酸介导的蛋白质修饰。我们将主要关注吲哚胺2，3-双加氧酶（IDO），一种催化色氨酸代谢为犬尿氨酸的酶。我们将使用转基因和敲除小鼠研究IDO在透镜蛋白修饰中的作用，并探讨高血糖和氧化应激对IDO活性的影响。犬尿氨酸介导的透镜蛋白损伤将通过色谱法和使用高度特异性单克隆抗体的免疫学试验进行评估。最后，在目标4中，我们将确定犬尿氨酸、MGO和DDO在透镜蛋白修饰中的关系。从这些实验中获得的累积信息将为我们提供对透镜老化和白内障形成的生化机制的重要见解。

项目成果

Candesartan attenuates diabetic retinal vascular pathology by restoring glyoxalase-I function.

• DOI: 10.2337/db10-0552
• 发表时间: 2010-12
• 期刊: Diabetes
• 影响因子: 7.7
• 作者: Miller AG;Tan G;Binger KJ;Pickering RJ;Thomas MC;Nagaraj RH;Cooper ME;Wilkinson-Berka JL
• 通讯作者: Wilkinson-Berka JL