Pathogenesis of Mitochondrial Retina Disease

项目总结 线粒体m.3243A&G变异是遗传性线粒体疾病的常见原因，这种疾病会导致 视网膜和其他组织的功能障碍。由于每个细胞的线粒体基因组拷贝数很高， 这种变异存在于各种比例的细胞中。突变体与野生型的比例如何 在任何给定的细胞、组织或个体中的M.3243等位基因与细胞和临床表型的关系不是很好。 明白了。在拟议的研究计划中，我们将确定这种变异是如何导致代谢功能障碍的 在眼细胞中，该变体优先分布在视网膜和潜在的哪些细胞类型中 发育过程中的代谢支持组织。 临床观察表明，视网膜色素上皮(RPE)是视网膜营养不良的驱动因素 3243A&GT；G病。使用来自携带m.3243A和GT；G的患者的诱导多能干细胞(IPSCs)， 我们将生成包含变种的各种受控比例的RPE。然后我们会让这些细胞 高通量检测以确定RPE正常代谢程序的紊乱。这种方法 将使我们能够确定RPE中m.3243A和G比例的增加如何影响线粒体和 新陈代谢功能。 我们和其他人之前已经观察到m.3243A&gt；G变种在 视网膜、脉络膜和其他组织的发育。具体地说，我们在初级眼睛组织中观察到 为RPE和外视网膜提供营养的脉络膜内皮细胞(CEC)对 在拟议的研究计划中，我们将从患者的IPSCs中产生神经视网膜和CECs 并测量m.3243A和gT；G的比例，以确定这些细胞是否能够以及如何根据 体外发育过程中的致病变异。 如果成功，这些研究将促进对m.3243A&gt；G变种致病性的了解。 视网膜。进一步了解这种线粒体变异体的细胞类型特异性分离和特异性 它引起的代谢功能障碍可能会导致治疗这个视网膜和其他视网膜的新的治疗靶点 由线粒体基因突变引起的疾病。

PROJECT SUMMARY The mitochondrial m.3243A>G variant is a common cause of genetic mitochondrial disease that causes dysfunction of the retina and other tissues. Due to the high copy number of the mitochondrial genome per cell, this variant exists in cells across a broad range of proportions. How the proportion of mutant to wildtype m.3243 allele in any given cell, tissue, or individual relates to the cellular and clinical phenotype is not well understood. In the proposed research program, we will identify how this variant causes metabolic dysfunction in ocular cells and in which cell types the variant is preferentially distributed in the retina and underlying metabolic support tissue during development. Clinical observation has implicated the retinal pigment epithelium (RPE) as the driver of retinal dystrophy in m.3243A>G disease. Using induced pluripotent stem cells (iPSCs) derived from patients carrying m.3243A>G, we will generate RPE containing various controlled proportions of the variant. We will then subject these cells to a high throughput assay to determine derangement of the normal metabolic program of RPE. This approach will allow us to determine how increasing levels of m.3243A>G proportion in RPE impacts mitochondrial and metabolic function. We and others have previously observed that the m.3243A>G variant segregates non-randomly during the development of the retina, choroid, and other tissues. Specifically, we have observed in primary ocular tissue that the choroidal endothelial cells (CEC) that supply nutrients to the RPE and outer retina select against m.3243A>G. In the proposed research program, we will generate neural retina and CECs from patient iPSCs and measure the proportion of m.3243A>G to determine if and how these cells are able to select against the pathogenic variant during in vitro development. When successful, these studies will advance knowledge of the pathogenicity of the m.3243A>G variant in the retina. Further understanding the cell type-specific segregation of this mitochondrial variant and the specific metabolic dysfunctions it causes may lead to novel therapeutic targets for the treatment of this and other retinal diseases caused by mutations in mitochondrial genes.