Impact of Lipofuscin in Retinal Pigment Epithelial Cells

脂褐素对视网膜色素上皮细胞的影响

• 批准号: 10211430
• 负责人: Janet Ruthe Sparrow
• 金额: $ 40.5万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10211430
• 关键词: 11 cis Retinal; Abbreviations; Acute; Address; Age related macular degeneration; Aldehydes; All-Trans-Retinol; American; Biochemical; Bolus Infusion; Cellular Assay; Clinical; Complex Mixtures; Darkness; Deposition; Diagnosis; Diet; Disease; Equilibrium; Family; Fundus; Gene Deletion; Genetic; Genotype; Glyoxal; Health; High Fat Diet; High Pressure Liquid Chromatography; Histologic; Image; Injections; Intake; International Unit; Investigation; Kinetics; Lasers; Lead; Legal Blindness; Light; Link; Lipids; Lipofuscin; Liquid Chromatography; Measurement; Measures; Medical Genetics; Membrane; Metabolism; Methods; Modeling; Monitor; Mus; Mutation; Nuclear; Obese Mice; Obesity; Ophthalmoscopy; Overweight; Pathogenicity; Patients; Performance; Periodicity; Pharmacotherapy; Phenotype; Phosphatidylethanolamine; Photoreceptors; Population; Prevalence; Process; Proteins; Public Health; Pyruvaldehyde; Quantitative Reverse Transcriptase PCR; RBP4 gene; Reactive Oxygen Species; Research; Retina; Retinal Degeneration; Retinal Diseases; Retinaldehyde; Retinitis Pigmentosa; Retinoids; Reverse Transcriptase Polymerase Chain Reaction; Risk; Role; Scanning; Serum; Source; Spectrometry, Mass, Electrospray Ionization; Stargardt' s disease; Structure of retinal pigment epithelium; Supplementation; Testing; Time; Toxic effect; Vitamin A; Weight; Weights and Measures; Work; adduct; clinical Diagnosis; confocal imaging; diet-induced obesity; disease natural history; experimental study; fluorophore; fundus imaging; genetic testing; human subject; lipid metabolism; macromolecule; novel; overweight adults; visual cycle

Project Summary/Abstract The prevalence of obesity in the US population is a growing health risk. We have observed that in high fat diet- induced obese (DIO) mice, vitamin A aldehyde adducts (bisretinoids) accumulate at elevated levels. Bisretinoids constitute the complex mixture of visual cycle adducts that form randomly in photoreceptor outer segments due to non-enzymatic reactions of retinaldehyde. These fluorophores are deposited in retinal pigment epithelial cells as components of phagocytosed outer segment membrane and constitute the lipofuscin of retina. It is well known that bisretinoid formation is modulated by the availability of vitamin A (i.e. visual cycle kinetics). The toxicity of this family of bisretinoids is attributable, at least in part, to their propensity to photogenerate reactive oxygen species and photodecompose into dicarbonyl- (glyoxal, GO; methylglyoxal, MG) and aldehyde-bearing fragments. The broad objectives of the studies proposed in this application are to explore links between the formation of toxic bisretinoids and dysregulation of vitamin A in association with obesity. Experiments proposed in Specific Aim 1 will undertake the novel exploration of relationships amongst a high fat diet, vitamin A, retinol binding protein 4 (Rbp4) and augmented bisretinoid in retina. Our working model is that increased delivery of vitamin A (retinol) to RPE under these conditions involves both Rbp4 and non-Rbp4 mechanisms. In mice fed a high fat diet and in obese ob/ob mice we will measure ocular levels of retinoid and bisretinoid and we will employ quantitative fundus autofluorescence imaging (qAF) for non-invasive measurement of bisretinoid. The role of RBP4 will be tested in mice by measuring serum Rbp4 and by studying mice deficient in Rbp4-/- due to gene deletion and drug treatment. Photoreceptor cell health will be evaluated by histometric analysis of outer nuclear layer. In the studies described in Specific Aim 2, we will address human subjects having excess weight by measuring bisretinoids using non-invasive quantitative fundus autofluorescence (qAF). In experiments presented in Specific Aim 3 we will challenge existing notions as to the conditions that govern the the extent of bisretinoid formation, the loss of bisretinoid due to photooxidation and factors determining the topographic distribution of SW-AF. To this end, we will quantify the relationship between vitamin A intake and bisretinoid formation. We will measure loss of bisretinoid by comparing levels in mice reared in darkness versus cyclic light. Bisretinoid lipofuscin will be measured chromatographically and by non-invasive qAF. The work will employ fundus imaging and biochemical, histological and cellular assays. Completion of this research will advance our understanding of previously unrecognized links amongst obesity, vitamin A metabolism and bisretinoid fluorophores.

项目摘要/摘要 美国人口中肥胖症的患病率是日益增长的健康风险。我们已经观察到，在高脂饮食中 诱导的肥胖（DIO）小鼠，维生素A醛加性（双苷）积聚在升高的水平上。双蛋白素 构成视觉循环加合物的复杂混合物，这些加合物在光感受器外部段中随机形成 视网膜醛的非酶反应。这些荧光团沉积在视网膜色素上皮细胞中 作为吞噬的外部段膜的成分，构成视网膜的脂肪霉素。众所周知 该双素形成是通过维生素A的可用性（即视觉循环动力学）调节的。的毒性 这个双丁素家族至少部分地归因于它们倾向于光生活性氧 物种并将光沉分成二氨基磺酰基（乙二醛，GO；甲基乙二醇，mg）和醛含量 碎片。 本应用程序提出的研究的广泛目标是探索形成之间的联系 与肥胖相关的维生素A的有毒双素和维生素A失调。提出的实验 AIM 1将对高脂饮食，维生素A，视黄醇结合之间的关系进行新的探索 蛋白质4（RBP4）和视网膜增强的双素类似。我们的工作模型是增加维生素A的递送 （视黄醇）在这些条件下对RPE涉及RBP4和非RBP4机制。在喂高脂肪的小鼠中 饮食和肥胖的ob/ob小鼠，我们将测量类维生素类和双素的眼部水平，我们将采用 用于非侵入性测量双层素的定量基底自动荧光成像（QAF）。的作用 RBP4将通过测量血清RBP4和研究缺乏RBP4 - / - 的小鼠在小鼠中进行测试。 缺失和药物治疗。光感受器细胞健康将通过外核的组织测量分析评估 层。在特定AIM 2中描述的研究中，我们将解决具有超重的人类受试者 使用非侵入性定量眼底自动荧光（QAF）测量双蛋白素。在实验中 在特定目的3中，我们将质疑现有的观念，即控制双素范围的条件 形成，由于光氧化而导致的双骨素的损失和确定地形分布的因素 SW-AF。为此，我们将量化维生素A摄入量和双骨素形成之间的关系。我们将 通过比较在黑暗中饲养的小鼠与环状光的小鼠的水平来测量双性素的损失。双素类似 脂肪霉素将通过色谱和非侵入性QAF进行测量。这项工作将采用眼底成像 以及生化，组织学和细胞测定法。这项研究的完成将提高我们对 肥胖，维生素A代谢和双肾上腺样子的肥胖症之间以前无法识别的联系。