Hippo Pathway Regulation of Müller Glial Cell-mediated Retinal Regeneration

项目摘要/摘要 视网膜疾病，如青光眼、黄斑变性和糖尿病视网膜病变，以及外伤性 损伤会导致视网膜神经元的丧失，从而导致视力的丧失，使世界各地的许多人失去了我们最宝贵的感觉之一。 因此，迫切需要设计策略来恢复丢失的视网膜神经元，从而恢复视力。当前 视网膜再生医学的努力在细胞替代方法上投入了大量资金。然而，它也可能 有可能诱导哺乳动物的视网膜经历一种内在的自我修复机制来再生神经元。 非哺乳类脊椎动物的视网膜，如斑马鱼，已知表现出惊人的视网膜能力 再生。在这里，Müler胶质细胞(MG)重新编程为增殖的视网膜祖细胞样细胞，继而 分化成新的光感受器，恢复视力。不幸的是，由于未知的原因， 哺乳动物的MGs已经失去了这种能力，或者它处于休眠状态。我们的长期目标是确定细胞和分子 阻止哺乳动物MG介导的视网膜再生的机制。通过这样做，我们或许能够设计出 绕过这一系统从而重新唤醒哺乳动物视网膜的再生潜力的策略。 在这个方案中，我们将测试河马信号通路主动阻断哺乳动物的假设。 镁通过阻止MG持续增殖和视网膜重编程实现视网膜再生 像祖先一样的状态。我们的具体目标将准确地定义河马信号在负调控中的要求 对视网膜损伤作出反应的MG持续的细胞周期重新进入。我们还将确定基因是否 河马信号的旁路导致MG重新编程到类似祖细胞的状态。最后，我们将评估 重新编程的MG的神经发生潜能。 这个项目将采用多学科方法，使用遗传功能丧失和功能获得实验， 命运图谱、表观基因组学和单细胞转录组学。通过完成上述目标，我们预计将拥有 确认河马途径是正常抑制MG增殖的内源性分子机制 重新编程为再生的祖细胞。这些数据将提供一个重要的分子切入点 进一步研究促进Müler胶质细胞介导的视网膜再生的新方法，并可能 对视网膜再生医学领域产生重大影响。我们预计随后将对更多 翻译，治疗方法，以调节河马途径的活动，以促进视网膜再生。

PROJECT SUMMARY/ABSTRACT Retinal diseases such as glaucoma, macular degeneration, and diabetic retinopathy, as well as traumatic injury, result in loss of retinal neurons and thus sight, depriving many worldwide of one of our most valued senses. Thus, there is a critical need to devise strategies to restore lost retinal neurons leading to vision recovery. Current efforts in retinal regenerative medicine are heavily invested in cell replacement approaches. However, it may also be possible to induce the mammalian retinae to undergo an intrinsic self-repair mechanism to regenerate neurons. The retinae of non-mammalian vertebrates, such as zebrafish, are known to exhibit the remarkable ability of retinal regeneration. Here, Müller glial cells (MGs) reprogram to proliferative, retinal progenitor-like cells that in turn differentiate into new photoreceptors leading to restoration of vision. Unfortunately, for unknown reasons, mammalian MGs have lost this ability, or it is dormant. Our long term goal is to identify the cellular and molecular mechanisms blocking mammalian MG-mediated retinal regeneration. By doing so, we may be able to devise strategies to bypass this system and thereby reawaken the regenerative potential of the mammalian retina. In this proposal, we will test the hypothesize that the Hippo signaling pathway actively blocks mammalian MG-mediated retinal regeneration by preventing sustained MG proliferation and reprogramming to a retinal progenitor-like state. Our specific aims will precisely define the requirement of Hippo signaling in negative regulation of persistent cell cycle re-entry of MGs responding to retinal damage. We will also determine whether genetic bypass of Hippo signaling results in MG reprogramming to a progenitor-like state. Finally, we will assess the neurogenic potential of reprogrammed MGs. This project will employ a multi-disciplinary approach using genetic loss- and gain-of-function experiments, fate mapping, epigenomics, and single cell transcriptomics. By completion of the described aims, we expect to have identified the Hippo pathway as the endogenous molecular mechanism normally restraining MG proliferation and reprogramming to regenerative, progenitor cells. These data will provide an essential molecular entry point from which to further investigate novel methods to promote Müller glial cell-mediated retinal regeneration and likely have significant influence on the field of retinal regenerative medicine. We anticipate subsequent investigation into more translational, therapeutic methods to modulate Hippo pathway activity to promote retinal regeneration.