Synapse rescue and neuroprotection in the retina

项目摘要 神经系统的功能，包括视觉，源于突触交流的精确模式。在……里面 神经退行性疾病，突触丢失可以早于细胞死亡和预测功能障碍。我们 最近发现，细胞黏附分子(CAM)Netrin-G配体2(NGL2)是 视杆感受器突触在整个生命过程中的维持以及NGL2病毒传递可以恢复突触 分别在成年野生型和Ngl2基因敲除小鼠中计数和诱导额外突触的形成。 基于这些发现，我们假设(1)NGL2的病毒传递可能能够挽救突触 遗传性视网膜变性(IRD)是一组遗传上不同的疾病，在这些疾病中，光感受器 失去突触，导致死亡，导致视觉障碍，包括失明。我们还假设(2)NGL2- 介导的突触挽救可能是神经保护和缓慢的光感受器死亡。我们的初步数据支持 这些假设，我们在这项提议中进一步测试。在目标1中，我们将检查突触丢失和 在野生型和Ngl2KO背景下，IRD模型的光感受器退化进程不同。我们会 确定NGL2病毒传递在多大程度上和何时可以拯救突触，保护光感受器， 并保持视力。最后，我们将评估NGL2基因治疗是否在IRD模型中推广 在发病机制和疾病进展上不同。CAM形成控制突触的大型蛋白质复合体 形成、维护和运行。这些络合物的分子组成和信号机制 几乎是未知的。在目标2中，我们将分析光感受器突触的ngl2复合体的组成。 并确定NGL2的S交互伙伴对突触维护、救援和 神经保护。许多在小鼠身上成功的治疗神经退行性变的方法在翻译中丢失了 对人类来说。神经回路的解剖、细胞组成、转录组和功能的差异 老鼠对人类的挑战促成了这一翻译挑战。我们已经开发了一套有机类型的培养系统 眼球摘除手术患者和器官捐赠者的人类视网膜。我们已建立税务局模式 在这个系统中。在目标3中，我们使用这些改进来测试NGL2及其交互伙伴的救援能力 突触和保护人类视网膜中的光感受器。我们的研究将共同决定 钙调素基因治疗神经退行性疾病。我们的突变不可知论方法可能是 广泛适用于遗传异质性的IRD，并可能适用于 神经系统的其他部分。

Project Summary Nervous system functions, including vision, arises from precise patterns of synaptic communication. In neurodegenerative diseases, synapse loss can long precede cell death and predict functional impairments. We recently discovered that the cell adhesion molecule (CAM) Netrin-G ligand 2 (NGL2) is required for the maintenance of rod photoreceptor synapses throughout life and that viral delivery of NGL2 can restore synapse numbers and induce the formation of extra synapses in adult wild-type and Ngl2 knockout mice, respectively. Based on these findings, we hypothesized (1) that viral delivery of NGL2 may be able to rescue synapses in inherited retinal degenerations (IRDs), a genetically heterogenous group of diseases in which photoreceptors lose synapses and die causing visual impairments, including blindness. We also hypothesized (2) that NGL2- mediated synapse rescue may be neuroprotective and slow photoreceptor death. Our preliminary data support these hypotheses, which we further test in this proposal. In Aim 1, we will examine whether synapse loss and photoreceptor degeneration progress differently IRD models on wild-type and Ngl2 KO backgrounds. We will determine to what extent and at which time viral delivery of NGL2 can rescue synapses, protect photoreceptors, and preserve vision. Finally, we will assess whether NGL2-gene therapy generalizes across IRD models that differ in pathogenesis and disease progression. CAMs nucleate large protein complexes that control synapse formation, maintenance, and function. The molecular composition and signaling mechanisms of these complexes is mostly unknown. In Aim 2, we will analyze the composition of NGL2 complexes at photoreceptor synapses and determine the contributions of NGL2’s interaction partners to synapse maintenance, rescue, and neuroprotection. Many therapeutic approaches to neurodegeneration that succeed in mice are lost in translation to humans. Differences in the anatomy, cellular composition, transcriptome, and function of neural circuits in mice vs. humans contribute to this translational challenge. We have developed an organotypic culture system of human retinas of patients undergoing enucleation surgery and organ donors. We have established an IRD model in this system. In Aim 3, we use these advances to test the ability of NGL2 and its interaction partners to rescue synapses and protect photoreceptors in the human retina. Together our studies will determine the potential of CAM-gene therapy for the treatment of neurodegenerative disease. Our mutation-agnostic approach could be widely applicable for genetically heterogenous IRDs and may be adaptable to neurodegenerative disease in other parts of the nervous system.