Soft drusen in rhesus macaques as a nonhuman primate model of early age-related macular degeneration

项目总结 老年性黄斑变性(AMD)是老年人视力丧失的主要原因，但目前的治疗方法 当干预措施可能受到不可逆转的细胞丢失的限制时，以晚期为目标。柔软的黄褐斑是首字母和 AMD的特点，但其发病机制尚不清楚，治疗的发展受到限制 缺乏好的动物模型。与大多数实验动物不同，非人类灵长类动物(NHP)拥有真正的黄斑 并自发形成类似于早期人类AMD的柔软玻璃体。之前对NHP玻璃体的研究已经被 观察性的、横断性的和定性的，由于维护老年动物的高成本，有限 纵向成像能力，以及缺乏下一代测序(NGS)和生物信息学支持。 我们最近在加州国家灵长类动物研究中心调查了一群独特的老年恒河猴 中心(CNPRC)，发现玻璃疱疹的患病率为30.6%。使用高分辨率多模式活体成像， 我们精确地测量了两年内的玻璃疣进展，并与组织学和超微结构相关联。 表现出类似人类软性黄褐斑的脂肪堆积。与心血管疾病类似，AMD的份额 流行病学危险因素，如高脂肪饮食，脂代谢的易感基因，以及类似于 伴有脂蛋白积聚、脂质氧化和补体基炎症的动脉粥样硬化斑块 回应。最近的初步研究表明，大剂量口服阿托伐他汀可以在某些情况下导致玻璃斑疹消退 AMD患者，但人类研究受到AMD表型的异质性和受试者的变异性的限制 饮食和血脂浓度。 在这项研究中，我们计划建立一个新的、独特的老年恒河猴软玻璃体猕猴队列，并进行 1)使用光谱域光学相干层析成像(SD-OCT)的详细眼部特征 精确测量视网膜各层并跟踪玻璃体体积，眼底自发荧光(Faf)测量RPE 脂褐素，2)代谢谱以测量空腹血浆代谢物、脂蛋白和载脂蛋白，以及 3)全基因组测序，以确定患有玻璃体的动物中可能与人类共享的遗传变异 AMD。接下来，我们将建立“西式”高脂肪/高糖饮食和大剂量阿托伐他汀的影响 ，并确定与饮食脂肪和RPE健康的可能相关性。 血脂。最后，我们将使用基于NGS的单细胞RNA测序(scRNA-Seq)来确定 黄斑RPE细胞在有或无软玻璃体、暴露于HFS饮食或治疗情况下的基因表达谱 用大剂量他汀类药物，对侧眼进行免疫组织化学评价和验证 基因集或途径，以及补体和其他免疫途径。总而言之，这些研究不会 只有建立一个非常有价值和独特的老年恒河猴队列，软性玻璃体适合 翻译研究，但也探索饮食脂类、口服他汀类药物、RPE基因表达和免疫的作用 早期AMD的NHP模型中的通路。

PROJECT SUMMARY Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly, but current treatments target advanced stages when interventions may be limited by irreversible cell loss. Soft drusen are the initial and hallmark feature of AMD, but their pathogenesis is unclear and the development of treatments is limited by the lack of good animal models. Unlike most laboratory animals, nonhuman primates (NHPs) possess a true macula and spontaneously develop soft drusen resembling early human AMD. Prior studies of NHP drusen have been observational, cross-sectional, and qualitative, owing to the high costs of maintaining aged animals, limited longitudinal imaging capabilities, and lack of Next-Generation Sequencing (NGS) and bioinformatics support. We recently surveyed a unique colony of geriatric rhesus macaques at the California National Primate Research Center (CNPRC), and found a 30.6% prevalence of drusen. Using high-resolution multimodal in vivo imaging, we precisely measured drusen progression over 2 years, with histological and ultrastructural correlates demonstrating lipid accumulation resembling human soft drusen. Similar to cardiovascular diseases, AMD share epidemiologic risk factors such as high fat diets, susceptibility genes in lipid metabolism, and deposits similar to atherosclerotic plaques with lipoprotein accumulation, lipid oxidation, and complement-based inflammatory responses. Recent pilot studies suggest that high-dose oral atorvastatin can cause drusen regression in some AMD patients, but human studies are limited by the heterogeneity of AMD phenotypes and variability in subject diets and serum lipid concentrations. In this study, we plan to establish a new, unique cohort of aged rhesus macaques with soft drusen, and perform 1) detailed ophthalmic characterization using spectral-domain optical coherence tomography (SD-OCT) to precisely measure retinal layers and track drusen volume, and fundus autofluorescence (FAF) to measure RPE lipofuscin, 2) metabolic profiling to measure fasting plasma metabolites, lipoproteins, and apolipoproteins, and 3) whole-genome sequencing to identify genetic variants in animals with drusen that may be shared with human AMD. Next, we will establish the impact of a “Western-style” high-fat/sugar (HFS) diet and high-dose atorvastatin on drusen progression and RPE health over 2 years, and determine possible correlations with dietary fats and serum lipids. Finally, we will employ NGS-based single-cell RNA-sequencing (scRNA-Seq) to determine the gene expression profile in macular RPE cells with and without soft drusen, exposure to HFS diet, or treatment with high-dose statin, followed by immunohistochemistry of contralateral eyes to evaluate and validate identified gene sets or pathways, as well as complement and other immune pathways. Together, these studies will not only establish a highly-valuable and unique cohort of aged rhesus macaques with soft drusen suitable for translational studies, but also explore the role of dietary lipids, oral statins, RPE gene expression, and immune pathways in this NHP model of early AMD.