Retinal Ganglion Cell Replacement in Clinically Relevant Models of Optic Neuropathy

本研究的目的是在一个物种中产生临床相关的视神经病变模型， 概括了人类视网膜和视神经的解剖学和生理学，可用于优化 诱导多能干细胞（iPSC）衍生的视网膜神经节细胞（RGC）的同种异体移植。我们将 使用树鼩，它有一个胶原，承载筛板和一个锥占主导地位的视网膜， 中央凹水平会聚到RGC上。我们将诱导和表征两个视神经病变，在这个 青光眼和外伤性视神经病变。同时，对树鼩的繁殖进行优化 来自成纤维细胞的视杯类器官作为用于移植的同种异体RGC的来源。我们将比较 这些诱导的RGC与原代树鼩 RGC的转录组谱。我们将优化移植 这些细胞在两种模型中通过鉴定：1）移植的最佳疾病阶段，2）移植的最佳疾病阶段。 3）如果调节内界膜， 整合，和4）如果共同治疗，锌螯合剂将改善移植视网膜的轴突生长 神经节细胞在表征这两种模型时，我们将量化细胞因子水平，神经胶质反应性， 轴突变性和RGC死亡。移植研究的主要结果是 功能：图形视网膜电图、体内钙成像和离体微电极记录。 次要结果包括定量位于神经节内的存活移植细胞 细胞层、轴突长度、树突形成和与上游神经元的突触连接。

The objective of this study is to generate clinically relevant models of optic neuropathy in a species that recapitulates the anatomy and physiology of the human retina and optic nerve that can be used to optimize allogenic transplantation of induced pluripotent stem cell (iPSC)-derived retinal ganglion cells (RGCs). We will use the tree shrew, which has a collagenous, load-bearing lamina cribrosa and a cone-dominant retina with fovea-level convergence onto the RGCs. We will induce and characterize two optic neuropathies in this species, glaucoma and traumatic optic neuropathy. Simultaneously, we will optimize generation of tree shrew optic cup organoids from fibroblasts as the source of allogenic RGCs for transplantation. We will compare the transcriptome profile of these induced RGCs to primary tree shrew RGCs. We will optimize transplantation of these cells in both models by identifying: 1) the optimal disease stage for transplantation, 2) the optimal differentiation stage of the RGCs for transplantation, 3) if modulating the inner limiting membrane will improve integration, and 4) if co-treatment a zinc chelator will improve axon outgrowth of the transplanted retinal ganglion cells. In characterizing the two models we will quantify changes in cytokine levels, glial reactivity, axon degeneration, and RGC death over time. Our primary outcomes for the transplantation studies will be functional: pattern electroretinograms, in vivo calcium imaging, and ex vivo microelectrode recordings. Secondary outcomes for will include quantification of surviving transplanted cells located within the ganglion cell layer, the length of axons, and dendrite formation and synaptic connectivity with upstream neurons.