Mitochondrial pyruvate transport in retinal health and disease

线粒体丙酮酸转运在视网膜健康和疾病中的作用

• 批准号: 10534738
• 负责人: Jianhai Du
• 金额: $ 40.32万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10534738
• 关键词: Age related macular degeneration; Aging; Aspartate; Biochemical; Cell Death; Cell Respiration; Cells; Choroid; Clinical; Codependence; Complex; Data; Defect; Disease; Ecosystem; Energy Metabolism; Foundations; Functional disorder; Glucose; Glutamates; Glutamine; Glycolysis; Glycolysis Inhibition; Goals; Health; Human body; Image; In Vitro; Individual; Infusion procedures; Ketone Bodies; Knock-out; Knockout Mice; Knowledge; Link; Macular degeneration; Mass Spectrum Analysis; Metabolic; Metabolism; Methodology; Mitochondria; Morphology; Muller' s cell; Neuroglia; Neurons; Neurotransmitters; Nutrient; Optical Coherence Tomography; Outcomes Research; Oxidative Phosphorylation; Phenotype; Photoreceptors; Pyruvate; Resolution; Retina; Retinal Degeneration; Retinal Diseases; Role; Structure of retinal pigment epithelium; Supporting Cell; Testing; Therapeutic; Tissues; Tracer; Transmission Electron Microscopy; Vascular blood supply; Vision; beta-Hydroxybutyrate; cell type; conditional knockout; glial activation; glucose transport; high resolution imaging; in vivo; inherited retinal degeneration; innovation; ketogenic diet; late-onset retinal degeneration; metabolomics; mitochondrial dysfunction; oxidation; preservation; pyruvate carrier; retinal rods; visual dysfunction

PROJECT SUMMARY/ABSTRACT The retina is the most metabolically active neuronal tissue in the human body. The defect in the energy metabolism of photoreceptor neurons and their supporting cells including glia and retinal pigment epithelium (RPE), emerges as an important underlying cause for retinal degenerative diseases such as inherited retinal degeneration and aging-related macular degeneration (AMD). Previous studies and data from our lab support that photoreceptors, glial cells, and RPE are biochemically adapted to form a metabolic ecosystem: 1) RPE transports glucose from choroid blood supply to photoreceptors; 2) Photoreceptors metabolize most of the glucose into lactate; 3) Lactate inhibits glycolysis in RPE to facilitate glucose transport; 4) Lactate stimulate Müller glia to synthesize glutamine for photoreceptors. The long term goal of this project is to define the metabolic interactions between photoreceptors and Müller glia and between RPE and outer retina in vivo and identify their roles in retinal function and degeneration. Mitochondrial pyruvate carrier (MPC) controls the entry of pyruvate from glycolysis into mitochondria for oxidative metabolism. We recently found that the deletion of MPC in the retina depletes glutamine and glutamate, inhibits glutamine utilization and enhancing ketone body oxidation, resulting in a progressive decline of visual function and retinal degeneration. Our preliminary data showed that the deletion of MPC in photoreceptors causes much milder phenotype than whole retina knockout, supporting the metabolic interaction that lactate is utilized by other cells. The objective of this proposal is to investigate the roles of mitochondrial pyruvate transport in photoreceptor, Müller cells and RPE in metabolic interactions, visual function, and retinal survival. We plan to conditionally knockout MPC in photoreceptors, glia or RPE separately and rigorously test our hypothesis using advanced tracer methodology, mass spectrometry, in vivo infusion with 13C tracers, high-resolution imaging of metabolites, visual function tests, optical coherence tomography, and transmission electron microscopy. The outcome of this research will establish a conceptual framework for retinal metabolism that describes how glucose is transported and utilized in different retinal cells and describes how disruption of metabolism in one kind of retinal cells impacts the metabolism, function, and viability of other retinal cells. This new knowledge will provide the basis for understanding the mechanisms of retinal degenerative diseases and lay the foundation for developing new treatments.

项目概要/摘要 视网膜是人体代谢最活跃的神经组织。缺陷在于 感光神经元及其支持细胞（包括神经胶质细胞和视网膜）的能量代谢 色素上皮细胞（RPE）是视网膜变性的重要根本原因 遗传性视网膜变性和衰老相关黄斑变性（AMD）等疾病。 我们实验室之前的研究和数据支持光感受器、神经胶质细胞和 RPE 生化适应形成代谢生态系统：1) RPE 从脉络膜转运葡萄糖 光感受器的血液供应； 2）光感受器将大部分葡萄糖代谢成乳酸； 3） 乳酸抑制 RPE 中的糖酵解以促进葡萄糖转运； 4) 乳酸刺激穆勒胶质细胞 合成光感受器的谷氨酰胺。该项目的长期目标是定义 光感受器和穆勒神经胶质细胞之间以及 RPE 和外视网膜之间的代谢相互作用 体内并确定它们在视网膜功能和退化中的作用。 线粒体丙酮酸载体 (MPC) 控制丙酮酸从糖酵解进入 线粒体用于氧化代谢。我们最近发现视网膜中MPC的缺失 消耗谷氨酰胺和谷氨酸盐，抑制谷氨酰胺利用并增强酮体 氧化，导致视功能逐渐衰退和视网膜变性。我们的 初步数据表明，光感受器中 MPC 的缺失导致的症状要轻得多。 表型优于全视网膜敲除，支持乳酸利用的代谢相互作用 由其他细胞。该提案的目的是研究线粒体丙酮酸的作用 光感受器、Müller 细胞和 RPE 在代谢相互作用、视觉功能和 视网膜存活。我们计划分别有条件地敲除光感受器、神经胶质细胞或 RPE 中的 MPC 并使用先进的示踪剂方法、质谱法严格检验我们的假设 13C示踪剂体内输注、代谢物高分辨率成像、视觉功能测试、光学 相干断层扫描和透射电子显微镜。 这项研究的成果将建立一个视网膜代谢的概念框架 描述了葡萄糖如何在不同的视网膜细胞中运输和利用，并描述了如何 一种视网膜细胞新陈代谢的破坏会影响新陈代谢、功能和活力 其他视网膜细胞。这些新知识将为理解 视网膜退行性疾病的发病机制，为开发新的视网膜退行性疾病奠定基础 治疗。