Proline metabolism in retinal health

项目总结/摘要 视网膜相关性黄斑变性（AMD）是老年人失明的主要原因。一个共同特点 在AMD中，视网膜色素上皮细胞（RPE）的早期损伤是光感受器之间的单层细胞 和脉络膜。RPE控制从脉络膜血液供应到外部视网膜和多条线路的营养运输 有证据表明，RPE代谢的改变是AMD的潜在机制。长期 这个项目的目的是确定RPE的关键代谢特征及其在AMD中的作用。 我们最近发现，除了葡萄糖，RPE优先使用脯氨酸（一种氨基酸）来为其代谢提供燃料。 人类脯氨酸代谢酶的突变可能导致脉络膜视网膜萎缩或视网膜病变。 退化观察到脯氨酸转运蛋白在RPE中高度富集，但在光感受器中不富集， 进一步支持我们的发现。脯氨酸转运蛋白是与AMD相关的新的风险基因。在我们的初步调查中 数据，我们表明，敲除脯氨酸转运阻断脯氨酸的利用和损害视觉功能。 该提案的目的是研究RPE中的脯氨酸代谢及其在视网膜变性中的作用。我们 计划使用先进的示踪剂严格研究脯氨酸在健康和患病RPE中的作用 方法学、质谱、体内输注、活体成像和脯氨酸转运蛋白敲除小鼠 模型 这项研究的结果将是建立一个概念框架的RPE代谢，描述 视网膜色素上皮细胞如何利用营养物质来维持外视网膜的代谢平衡。这些新知识将 为了解AMD的发病机制提供依据，为开发新的 治疗。

PROJECT SUMMARY/ABSTRACT Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. A common feature in AMD is the early damage of retinal pigment epithelium (RPE), a monolayer of cells between photoreceptors and choroid. RPE controls nutrient transport from choroid blood supply to the outer retina and multiple lines of evidence show that the altered metabolism in RPE is the underlying mechanism for AMD. The long-term goal of this project is to identify key metabolic features of RPE and the roles that they play in AMD. We recently found that besides glucose, RPE preferentially uses proline, an amino acid, to fuel its metabolism. Mutations of enzymes in proline metabolism in humans could cause chorioretinal atrophy or retinal degeneration. The observation that a proline transporter is highly enriched in RPE but not in photoreceptors, further supporting our finding. The proline transporter is a novel risk gene linked to AMD. In our preliminary data, we show that knockout of the proline transporter blocks proine utilization and impairs visual function. The objective of this proposal is to study proline metabolism in RPE and its role in retinal degeneration. We plan to rigorously investigate the role of proline in healthy and diseased RPE using advanced tracer methodology, mass spectrometry, in vivo infusion, live imaging, and proline transporter knockout mouse models. The outcome of this research will be to establish a conceptual framework for RPE metabolism that describes how RPE uses nutrients to maintain metabolic homeostasis with the outer retina. This new knowledge will provide the basis for understanding the mechanisms of AMD and lay the foundation for developing new treatments.