Novel model systems for the study of cone disorders and other heritable retinal diseases

项目总结/摘要 视网膜变性疾病是世界范围内无法治愈的失明的常见原因， 数百万人的生命。FDA批准的治疗这些疾病的唯一方法是基因治疗， RPE 65突变导致Leber先天性黑蒙和视网膜色素变性。一个主要 开发有效疗法的限制是使用动物模型， 人类的状况特别是对于视锥细胞疾病，使用具有视杆细胞占主导地位的视网膜的动物的研究 没有真正的黄斑有实质性的局限性。相比之下，非人类的富含锥体的黄斑 灵长类动物（NHP）密切反映了人类的视网膜。因此，定义明确的NHP模型 遗传性视网膜疾病，特别是视锥细胞疾病，更能预测人类状况， 更有效地推进新疗法所必需的。我们建议开发一系列新颖的， 人遗传性视网膜疾病的自发NHP模型。恒河猴的行为观察 加州国家灵长类动物研究中心的猕猴（Macaca mulatta）发现了一系列 显示出明显的视觉障碍。基因测试显示，四只动物 PDE 6C基因中的破坏性突变是纯合子的，该突变以前与 视锥细胞营养不良对猕猴进行的暗视和明视全视野视网膜电图 PDE 6C突变纯合子表现出相对正常的视杆细胞反应，但没有视锥细胞反应。 无论如何回应。一个微妙的，但特征性的靶心黄斑病变被确定使用眼底 摄影、蓝色自体荧光和荧光素血管造影，同时使用 光谱域光学相干断层扫描。我们对这群人的基因调查还发现 在其他7种人类视网膜疾病基因中发生突变的猕猴， 基因或蛋白质功能，指出可能的其他新模型。为了开发PDE 6C灵长类动物 模型的视锥细胞营养不良，并使这个和其他新的NHP模型可用于视觉研究 社区，我们提出了四个具体目标：1）识别和遗传特征的新的NHP模型 通过DNA测序对人类视网膜疾病进行分析，2）对NHP进行完整的眼科表型分析 视网膜疾病模型，3）繁殖具有PDE 6C视锥营养不良的NHP群体，和4）比较 基于细胞和基因替代疗法在患有PDE 6C锥体营养不良突变的猕猴中的应用。 这项工作的成功完成将产生一个具有良好特征的遗传性的新动物模型。 与现有模型相比，锥体营养不良与人类疾病具有显著更大的相似性，因此 从而为后续的人体试验提供实质上更好的转化。此外，受影响的动物将 提供给更广泛的视觉研究社区，以及其他具有类似潜力的新模型 将被识别。

Project Summary/Abstract Retinal degeneration diseases are a common cause of untreatable blindness worldwide, affecting the lives of millions. The only FDA-approved treatment for these disorders is gene therapy for specific RPE65 mutations that cause Leber’s congenital amaurosis and retinitis pigmentosa. One major limitation to the development of effective therapies is the use of animal models that poorly replicate the human condition. Particularly for cone disorders, studies that use animals with a rod-dominant retina and no true macula have substantive limitations. By contrast, the cone-rich macula of nonhuman primates (NHP) closely mirrors that of the human retina. Consequently, well-defined NHP models of heritable retinal diseases, particularly cone disorders, that are more predictive of human conditions are necessary to more efficiently advance new therapies. We propose to develop a series of novel and spontaneous NHP models of human inherited retinal diseases. Behavioral observations of rhesus macaques (Macaca mulatta) at the California National Primate Research Center identified a series of macaques that displayed apparent visual impairment. Genetic testing showed that four animals are homozygous for a damaging mutation in the PDE6C gene, which has previously been associated with cone dystrophy in humans. Scotopic and photopic full-field electroretinograms performed on macaques homozygous for the PDE6C mutation demonstrated a relatively normal rod response but no cone response whatsoever. A subtle but characteristic bullseye maculopathy was identified using fundus photography, blue autofluorescence, and fluorescein angiography with concurrent foveal thinning using spectral-domain optical coherence tomography. Our genetic survey of this population also identified macaques with mutations in 7 other human retinal disease genes that are predicted to severely damage gene or protein function, pointing to possible additional new models. To develop the PDE6C primate model of cone dystrophy, and make this and other new NHP models available to the vision research community, we propose four Specific Aims: 1) to identify and genetically characterize new NHP models of human retinal disease via DNA sequencing, 2) to perform complete ophthalmic phenotyping of NHP models of retinal disease, 3) to breed a colony of NHPs with PDE6C cone dystrophy and 4) to compare cell-based and gene replacement therapies in macaques with PDE6C cone dystrophy mutations. Successful completion of this work will produce a well-characterized new animal model of inherited cone dystrophy with significantly greater similarity to human disease than existing models, thus providing substantially better translation to subsequent human trials. In addition, affected animals will be made available to the wider vision research community, and other new models with similar potential will be identified.