Human RPE metabolism and metabolite transport

 描述（由申请人提供）：能量代谢和代谢物转运对于视网膜色素上皮（RPE）的活力和功能至关重要。理解这些过程及其在疾病状态中的扰动具有根本的重要性。我们的初步结果表明，还原羧化在RPE中比在视网膜或其他神经元细胞或组织中更为突出。我们发现RPE细胞中还原羧化缺乏， 来源于Sorsby眼底营养不良（SFD）患者的诱导多能干细胞（iPSC）细胞，并且在氧化应激条件下，氧化应激是AMD早期发病机制的关键组成部分。由于RPE细胞中还原性羧化的潜在疾病相关性，我们将使用先进的示踪方法、真实的时间线粒体功能分析和活体成像来检查RPE细胞中还原性羧化的作用。我们在一个良好控制的细胞培养系统中观察到，人RPE优先将代谢物输出到视网膜侧。我们还发现代谢物转运在SFD iPSC衍生的RPE细胞中受损。本研究拟系统研究细胞外结构和细胞内状态对SFD RPE代谢物转运的调控，并探讨SFD RPE代谢物转运缺陷的机制。这项拟议的研究将产生一个代谢物的参考数据集，这些代谢物优先被RPE输出和消耗，确定还原羧化在RPE细胞代谢中的作用，并揭示RPE中代谢物转运的正常和疾病相关变化。这一新的信息可用于开发视网膜退行性疾病的治疗。

 DESCRIPTION (provided by applicant): Energy metabolism and metabolite transport are essential for the viability and function of the retinal pigment epithelium (RPE). Understanding these processes and their perturbations in disease states is of fundamental importance. Our preliminary results show reductive carboxylation is much more prominent in RPE than in retina or other neuronal cells or tissues. We found that reductive carboxylation is deficient in RPE cells derived from induced pluripotent stem cell (iPSC) cells made from a Sorsby's Fundus Dystrophy (SFD) patient and under conditions of oxidative stress, a critical component of early pathogenesis of AMD. Because of the potential disease relevance of reductive carboxylation in RPE cells, we will examine the role of reductive carboxylation in RPE cells using advanced tracer methodology, real time mitochondrial function analysis and live imaging. We observed in a well-controlled cell culture system that human RPE preferentially exports metabolites to the retinal side. We also found that metabolite transport is impaired in SFD iPSC-derived RPE cells. We plan to systematically investigate the regulation of metabolite transport by extracellular structure and intracelluar state, and identify the mechanisms of the defective transport in SFD RPE. This proposed research will generate a reference data set of metabolites that are preferentially exported and consumed by the RPE, determine the role of reductive carboxylation in RPE cell metabolism, and reveal normal and disease-relevant changes in metabolite transport in RPE. This new information can be used to develop treatment of retinal degenerative diseases.