Uncovering novel targets for retinal ganglion cell neuroprotection and axon regeneration

项目摘要 像中枢神经系统的其他神经元一样，视网膜神经节细胞(RGC)-- 视网膜--损伤后不能再生。青光眼是导致失明的主要原因，RGC轴突变性 以及随后的死亡是导致不可逆转的视力丧失的两个关键病理事件。然而，没有 有有效的治疗方法来防止RGC的脆弱性和损失。发展的关键障碍 新的治疗方法是我们对调节RGC存活和轴突的机制了解不足 再生。利用小鼠视神经挤压(ONC)模型，以前我们发现去除视神经 磷酸酶和张力蛋白同源蛋白(PTEN)显著促进轴突再生。最近，我们 利用ONC模型并进行了大规模的体内CRISPR筛查，以确定这种 机械装置。我们的筛查揭示了多个基因，它们从视网膜细胞中移除可促进RGC存活 和/或轴突再生。最强的保护表型之一属于c-jun N-基因敲除- 末端激酶-相互作用蛋白3(JIP3)。然而，JIP3基因敲除不仅未能促进轴突 在存活的视网膜节细胞中再生，它取消了PTEN缺失诱导的轴突再生。在这里，我建议 视神经损伤后不同时间点有无JIP3和/或PTEN的视网膜节细胞转录分析 神经损伤以进一步研究JIP3依赖的RGC存活的分子程序，以及PTEN- 依赖轴突再生。此外，我将测试JIP3对小鼠青光眼的神经保护作用 眼压升高导致RGC丢失的模型。

Project Summary Like other neurons of the central nervous system, retinal ganglion cells (RGCs)—the projection neurons of the retina—fail to regenerate after injury. In glaucoma, a leading cause of blindness, degeneration of RGC axons and their subsequent death are two key pathological events that lead to irreversible loss of vision. However, no effective treatments to prevent RGC vulnerability and loss are available. A critical obstacle toward developing novel therapeutics is our insufficient understanding of mechanisms that regulate RGC survival and axon regeneration. Using mouse optic nerve crush (ONC) model, previously, we discovered that removal of phosphatase and tensin homolog (PTEN) protein significantly promotes axon regeneration. More recently, we leveraged ONC model and undertook a large-scale in vivo CRISPR screen to identify key regulators of such mechanisms. Our screen revealed multiple genes whose removal from retinal cells promoted RGC survival and/or axon regeneration. One of the strongest protective phenotypes belonged to the knockout of the c-Jun N- terminal kinases-Interacting Protein 3 (JIP3). However, knockout of JIP3 not only fails to promote axon regeneration in survived RGCs, it abolishes axon regeneration induced by PTEN deletion. Here, I propose performing transcriptomic analysis of RGCs with or without JIP3 and/or PTEN at different time points after optic nerve injury to further investigate molecular programs underlying JIP3-dependent RGC survival, and PTEN- dependent axon regeneration. Furthermore, I will test the neuroprotective effect of JIP3 in a mouse glaucoma model in which elevation of intraocular pressure causes RGC loss.