QUANTITATIVE ANAYLSIS OF AGING RETINA

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，其治疗方法的改进在于更好地了解早期ARM. On我们的初步数据的基础上，我们假设早期年龄相关性黄斑病变是一种眼部动脉粥样硬化。根据这一假说，ARM的病理生理学涉及两种机制，类似于在大动脉内壁的老化和动脉粥样硬化过程中发生的机制：根据这一假说，大动脉内壁：与年龄相关的血清脂蛋白衍生的酯化胆固醇和未酯化胆固醇沉积。（EC和UC）;以及在局部细胞参与下富含UC的物质的疾病相关沉积。利用人类供体眼睛的独特资源和实验性动脉粥样硬化的成熟动物模型，我们提出了三个目标来测试这一假设的几个预测。1)在人眼中，我们将确定布鲁赫膜的EC和UC含量如何随年龄和视网膜位置而变化，使用菲律宾荧光和数字显微镜。我们将通过确定溶剂如何影响菲律宾荧光和超微结构来确定布鲁赫膜中富含EC的颗粒。我们将采用酶法和气相色谱-质谱法表征分离的布鲁赫膜的脂质组成。2)在人眼中，我们将确定膜碎片的形态发生在周边视网膜。我们将使用菲律宾荧光，数字显微镜和超微结构体视学来确定膜碎片和光感受器外节的UC含量。3)在兔眼中，我们将确定是否延长饮食的胆固醇补充的结果在布鲁赫的膜EC EC的沉积，使用放射自显影局部全身注射放射性标记的酪胺-纤维二糖-低密度脂蛋白在组织切片。从这些目标的结果将是有价值的，在何种程度上评估ARM和动脉粥样硬化共享发病机制方面的积累和来源的细胞外胆固醇。需要这些信息以确定是否应考虑将动脉粥样硬化的有效治疗用于早期ARM的治疗。

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.