Molecular mechanism underlying late-onset retinal/macular degeneration

摘要 这项建议的目标是了解分子基础的良好表征， 单基因疾病，晚发性视网膜/黄斑变性（L-ORD/L-ORMD），概括了主要的 具有玻璃疣形成表型的其他黄斑变性（MD）的特征，包括AMD，尽管具有 后来发作。L-ORMD是一种显性黄斑变性，其特征在于存在暗适应 早在30多岁时就出现异常，40多岁时出现玻璃疣样RPE下沉积物，视力逐渐丧失， 以及50年代的新血管形成导致了不可逆的失明。主要产品：Doyne Honeycomb Retinal 营养不良（DHRD）和Sorsby眼底营养不良（SFD）以及复杂疾病AMD是 其他具有玻璃疣表型的MD的实例。我们鉴定了C1q-TNF相关蛋白基因的突变， 5（CTRP 5/C1QTNF 5）。CTRP 5由RPE分泌并与EFEMP 1相互作用， TIMP3，其基因分别与DHRD和SFD有关。这三种蛋白质都是 细胞外基质（ECM）的组分，并且是ECM调节剂HTRA1的底物。同样地， AMD相关蛋白CFH和C3也是ECM的成员和HTRA 1的底物。这些发现 支持Bruch膜（BrM）（RPE的专门ECM）在MD病理学中的作用。S163R Ctrp5 我们开发的突变敲入（KI）小鼠模型（KI/Wt和KI/KI）模拟人L-ORMD 表型包括亚RPE沉积和BrM异常。我们还建立了iPSC-RPE， L-ORMD患者使用这些模型，我们将（1）描述基因调控景观 通过分析视网膜色素变性的染色质可及性和转录组的变化， 作为L-ORMD病理学的主要和次要靶点的细胞，（2）分析L-ORMD病理学的蛋白质组谱。 这些小鼠的BrM-脉络膜，以评估ECM组成和基质细胞蛋白的变化， 与衰老和疾病进展相关的信号传导，以确定ECM在L-ORMD中的作用 和（3）使用模型验证发现在L-ORMD病理学中起作用的分子网络 系统.这项研究的结果有可能描绘出每个细胞中的分子网络是如何形成的。 视网膜细胞类型分别受到衰老和疾病进展的影响，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。拟议的研究将 显著提高了我们对L-ORMD以及其他迟发性病理学的理解， 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.