Manipulating retinal progenitor cells

描述（由申请人提供）：该修订的R21申请的总体目标是确定小鼠视网膜祖细胞（RPC）在其正常胚胎环境外分化为视网膜神经节细胞（RGC）的潜力。胚胎或胚胎干细胞衍生的RPC在成人视网膜中分化成功能性RGC的潜力将通过将其移植到其中RGC已被遗传消融的成人宿主视网膜中来体内检查。已经开发了一种新的遗传小鼠模型，其中一些或所有RGC可以在成年期的任何时间被消融，从而导致视神经变性。来自这些小鼠的视网膜为细胞移植方法提供了独特的微环境，以恢复RGC并再生视神经或防止其进一步变性。实验计划取决于了解视网膜发生过程中控制RGCs的特异性和分化的关键调控事件。原神经碱性螺旋-环-螺旋因子Math 5在控制RGC发育的基因调控网络中占据中心节点，因为它负责赋予RPC获得RGC命运的能力。待检验的假设是表达Math 5的RPC是一种独特的、可分离的RPC亚群，并且表达Math 5的RPC即使被置于成人视网膜的微环境中也将保留其发育潜力。为了研究表达Math 5的RPC与成人视网膜微环境之间的相互作用，将研究纯化的表达Math 5的RPC在移植到RGC消融的成人视网膜中后分化成功能性RGC的潜力。确定胚胎RPC适应成人视网膜微环境的发育潜力将有助于了解视网膜发育以及建立更强大的方法来预防，修复和再生受损的视网膜。成年小鼠RGCs的基因消融为视网膜再生提供了一种新的模型。对允许RPC在其正常环境中分化成RGC的机制的了解为从胚胎视网膜或多能胚胎干细胞产生大量功能性RGC祖细胞提供了基础。 公共卫生相关性：该项目将揭示胚胎视网膜祖细胞的特性的新见解，这些细胞在成人神经视网膜中产生视网膜神经节细胞。实验旨在确定视网膜祖细胞适应成人视网膜微环境而不是正常胚胎微环境的潜力。该项目将有助于了解视网膜发育，并建立新的方法来再生受损的视网膜，预防或修复视神经变性的视网膜病变，如视神经炎，缺血性视神经病变和青光眼。

DESCRIPTION (provided by applicant): The overall objective of this revised R21 application is to determine the potential of mouse retinal progenitor cells (RPCs) to differentiate into retinal ganglion cells (RGCs) outside of their normal embryonic environment. The potential of embryo- or embryonic stem cell-derived RPCs to differentiate into functional RGCs in adult retinas will be examined in vivo by transplanting them into adult host retinas in which RGCs have been genetically ablated. A novel genetic mouse model has been developed in which some or all RGCs can be ablated at any time during adult life with the consequent degeneration of the optic nerve. Retinas from these mice provide a unique microenvironment for cell transplantation approaches to restore RGCs and regenerate the optic nerve or prevent its further degeneration. The experimental plan depends on understanding the key regulatory events that control the specification and differentiation of RGCs during retinogenesis. The proneural basic helix-loop-helix factor Math5 occupies a central node in the gene regulatory network that controls RGC development because it is responsible for endowing RPCs with the competence to acquire a RGC fate. The hypothesis to be tested is that Math5-expressing RPCs are a distinct, isolatable RPC subpopulation and that Math5-expressing RPCs will retain their developmental potential even when placed into the microenvironment of the adult retina. To investigate the interactions between Math5-expressing RPCs and the adult retinal microenvironment, the potential of purified Math5-expressing RPCs to differentiate into functional RGCs after transplantation into RGC- ablated adult retinas will be investigated. Determining the developmental potential of embryonic RPCs to adapt to the microenvironment of the adult retina will contribute towards an understanding of retina development as well as establishing more robust methods to prevent, repair and regenerate damaged retinas. Genetic ablation of RGCs in adult mice provides a new model for retinal regeneration. Knowledge of the mechanisms that allow RPCs to differentiate into RGCs in their normal environment provides the underpinning for generating large numbers of functional RGC progenitors from embryonic retinas or pluripotent embryonic stem cells. PUBLIC HEALTH RELEVANCE: This project will reveal new insights into the properties of the embryonic retinal progenitor cells that give rise to retinal ganglion cells in the adult neural retina. Experiments are designed to determine the potential of retinal progenitor cells to adapt to the microenvironment of the adult retina rather than their normal embryonic microenvironment. The project will contribute to an understanding of retinal development as well as establishing new approaches to regenerate damaged retinas and prevent or repair optic nerve degeneration in retinal pathologies such as optic neuritis, ischemic optic neuropathy, and glaucoma.