QUANTITATIVE ANAYLSIS OF AGING RETINA

视网膜老化的定量分析

• 批准号: 6384504
• 负责人: Christine A Curcio
• 金额: $ 31.42万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-15 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6384504
• 关键词: adult human (21+); age difference; aging; atherosclerosis; autoradiography; blood lipoprotein metabolism; chemical association; cholesterol; disease /disorder model; electron microscopy; esterification; extracellular matrix proteins; eye disorder diagnosis; gas chromatography mass spectrometry; human old age (65+); human subject; human tissue; immunocytochemistry; laboratory rabbit; lipid bilayer membrane; low density lipoprotein; pathologic process; radiotracer; retina disorder; visual photoreceptor

Improved treatments for age-related maculopathy (ARM), the leading cause of untreatable vision loss among the elderly in the developed world, lie in better understanding of early ARM. On the basis of our preliminary data, we hypothesize that early age-related maculopathy is an ocular form of atherosclerosis. According to this hypothesis, the pathophysiology of ARM involves two mechanisms similar to those that occur during aging and atherosclerosis in the inner wall of the large arteries: According to this hypothesis, the inner wall of the large arteries: an age-related deposition of serum-lipoprotein-derived esterified cholesterol and unesterified cholesterol (EC and UC) in association with extracellular matrix proteins; and a disease-related deposition of a UC-rich material with the participation of local cells. Using a unique resource for human donor eyes and a well-established animal model for experimental atherosclerosis, we propose three aims to test several predictions of this hypothesis. 1) In human eyes, we will determine how the EC and UC content of Bruch's membrane varies with age and retinal location, using filipin fluorescence and digital microscopy. We will identify EC-rich particles in Bruch's membrane by determining how solvents affect filipin fluorescence and ultra-structure. We will characterize the lipid composition of isolated Bruch's membrane using an enzymatic assay and gas-chromatography-mass spectrometry. 2) In human eyes, we will determine the morphology of membranous debris occurs in peripheral retina. We will determine the UC content of membranous debris and photoreceptor outer segments using filipin fluorescence, digital microscopy, and ultrastructural stereology. 3) In rabbit eyes, we will determine if an extended diet of cholesterol supplementation results in deposition of EC in Bruch's membrane EC, using autoradiography to localized systemically injected radiolabeled tyramine-cellubiose-low density lipoprotein in tissue sections. Results from these aims will be valuable in assessing the extent to which ARM and atherosclerosis share pathogenetic mechanisms with regard to the accumulation and source of extracellular cholesterol. This information is required in order to determine if effective treatments for atherosclerosis should be considered for the treatment of early ARM.

年龄相关性黄斑病变 (ARM) 是发达国家老年人无法治愈的视力丧失的主要原因，改善治疗方法的关键在于更好地了解早期 ARM。根据我们的初步数据，我们假设早期年龄相关性黄斑病是动脉粥样硬化的一种眼部形式。根据这一假说，ARM 的病理生理学涉及两种与大动脉内壁衰老和动脉粥样硬化过程中发生的机制类似的机制：以及在局部细胞的参与下与疾病相关的富含 UC 的物质的沉积。利用人类捐献眼睛的独特资源和完善的实验性动脉粥样硬化动物模型，我们提出了三个目标来检验这一假设的几个预测。 1) 在人眼中，我们将使用菲律宾荧光和数字显微镜确定布鲁赫膜的 EC 和 UC 含量如何随年龄和视网膜位置变化。我们将通过确定溶剂如何影响菲律宾荧光和超微结构来识别布鲁赫膜中富含 EC 的颗粒。我们将使用酶测定和气相色谱-质谱法来表征分离的布鲁赫膜的脂质组成。 2）在人眼中，我们将确定发生在视网膜周边的膜碎片的形态。我们将使用菲律宾荧光、数字显微镜和超微结构体视学测定膜碎片和光感受器外节的 UC 含量。 3) 在兔眼中，我们将使用放射自显影技术在组织切片中局部全身注射放射性标记的酪胺-纤维二糖-低密度脂蛋白，确定长期补充胆固醇饮食是否会导致 EC 在 Bruch 膜 EC 中沉积。这些目标的结果对于评估 ARM 和动脉粥样硬化在细胞外胆固醇积累和来源方面共有的发病机制的程度将很有价值。需要这些信息来确定是否应考虑采用有效的动脉粥样硬化治疗方法来治疗早期 ARM。