Molecular mechanism underlying late-onset retinal/macular degeneration

摘要 这项提议的目标是理解具有良好特征的 单基因疾病，迟发性视网膜/黄斑变性(L-ORD/L-OMD) 包括AMD在内的其他黄斑变性(MD)的特点是形成玻璃体形成表型 起病较晚。L黄斑变性是一种以暗适应为特征的显性黄斑变性 早在30多岁就出现异常，40多岁时出现玻璃体样亚RPE沉积，视力进行性丧失， 和50年代的新生血管导致不可逆转的失明。占主导地位的多因蜂窝视网膜 营养不良(DHRD)和索斯比眼底营养不良(SFD)以及复杂的AMD疾病是 其他表现为玻璃疱疹的MD的例子。我们发现了C1q-肿瘤坏死因子相关蛋白基因的突变 5(CTRP5/C1QTNF5)。CTRP5由RPE分泌，与EFEMP1和EFEMP1相互作用 TIMP3基因分别与DHRD和SFD有关。这三种蛋白质都是 是细胞外基质(ECM)的组成部分，是ECM调节剂HTRA1的底物。同样， AMD相关蛋白CFH和C3也是细胞外基质和HTRA1底物的成员。这些发现 支持Bruch膜(BRM)在MD病理中的作用，BRM是RPE的一种特殊的ECM。S163R CTRP5 我们建立的突变敲入(Ki)小鼠模型(Ki/Wt和Ki/Ki)模拟了人类的L-ORMD 表型包括亚RPE沉积和BRM异常。我们还建立了IPSC-RPE L口腔炎患者。使用这些模型，我们将(1)描述基因调控的图景 通过描述染色质可及性和视网膜转录组的变化来研究潜在的疾病病理 细胞是L口腔炎病理的主要和次要靶点，(2)分析口腔炎的蛋白质组图谱 BRM-脉络膜对这些小鼠评估ECM组成和基质细胞蛋白的变化与作用 与衰老和疾病进展相关的信号转导，以确定细胞外基质在L牙周炎中的作用 病理和(3)用模型验证分子网络在L-口腔炎病理中的作用 系统。这项研究的结果有可能描绘出每个物种的分子网络是如何 视网膜细胞类型受到年龄和疾病进展的单独影响，如果视网膜细胞类型 通过调节表观基因组来适应疾病的慢性细胞应激。建议的研究将 显著提高了我们不仅对L-口蹄疫，而且对其他晚发型病理的了解，如 AMD。

ABSTRACT The goal of this proposal is to understand the molecular underpinnings of the well-characterized monogenic disease, Late Onset Retinal/Macular Degeneration (L-ORD/L-ORMD) that recapitulates the major features of other macular degenerations (MDs) with a drusen forming phenotype including AMD although with later onset. L-ORMD is a dominant macular degeneration characterized by the presence of dark adaptation abnormality as early as in the 30s, drusen-like sub-RPE deposits in the 40s, progressive loss of visual acuity, and neovascularization in the 50s leading to irreversible blindness. The dominant Doyne Honeycomb Retinal Dystrophy (DHRD) and Sorsby's Fundus Dystrophy (SFD) as well as the complex disease AMD are examples of other MDs with drusen phenotype. We identified mutations in the gene C1q-TNF-Related Protein 5 (CTRP5/C1QTNF5) in patients with L-ORMD. CTRP5 is secreted by RPE and interacts with EFEMP1 and TIMP3 whose genes have been implicated in DHRD and SFD respectively. All three proteins are components of the extracellular matrix (ECM) and are substrates of the ECM regulator HTRA1. Likewise, AMD associated proteins CFH and C3 are also members of ECM and substrates of HTRA1. These findings support a role for Bruch's membrane (BrM), a specialized ECM of RPE, in MD pathology. S163R Ctrp5 mutation knock-in (KI) mouse models (KI/Wt & KI/KI) that we developed mimic the human L-ORMD phenotype including sub-RPE deposits and BrM abnormalities. We have also established iPSC-RPE of patients with L-ORMD. Using these models, we will (1) characterize the gene regulatory landscape underlying disease pathology by profiling changes in chromatin accessibility and the transcriptome of retinal cells that are the primary and secondary targets of L-ORMD pathology, (2) analyze the proteome profile of BrM-Choroid of these mice to evaluate changes in ECM composition and matricellular proteins with role in signaling associated with aging and with progression of disease to determine the role of ECM in L-ORMD pathology and (3) validate the molecular networks found to play a role in L-ORMD pathology using model systems. The outcomes of this study have the potential to delineate how the molecular networks in each retinal cell type is individually impacted by aging and by progression of disease, and if the retinal cell types adapt to the chronic cellular stress of disease by modulating the epigenome. The studies proposed will significantly enhance our understanding of not only L-ORMD, but also other late-onset pathologies such as AMD.