Using light-sensitive channels to restore vision for blinding retinal diseases

描述（由申请人提供）：视网膜退行性疾病中感光细胞的严重丧失可能导致部分或完全失明。目前，一旦光感受器丢失，没有有效的治疗方法来恢复失去的视力。我们正在探索一种新的策略，通过基因将光不敏感的第二或第三级视网膜神经元转化为光敏细胞，从而使缺乏光感受器的视网膜具有光敏性。概念验证研究已经证明了通道视紫红质-2 （ChR2）和盐紫红质（HaloR）在视网膜内神经元中的功能表达的可行性，并导致视网膜退化小鼠模型视网膜中ON和OFF光反应的恢复。本提案的目标将继续在啮齿动物模型中进行原理验证研究，以解决对开发这种治疗策略用于临床应用至关重要的问题。具体来说，我们将研究体内视网膜内神经元中HaloR的长期表达，并探讨视网膜神经元中ChR2和HaloR介导的光反应的潜在机制。我们还将探索ChR2和HaloR在视网膜内神经元和/或视网膜神经节细胞亚细胞区室的特定群体中的靶向表达。此外，我们将在正常和视网膜退行性小鼠中研究ChR2和halor介导的靶细胞及其下游神经元的光响应特性。我们的长期目标是开发一种治疗或治愈由视网膜变性引起的失明的新策略。拟议的研究将为推进这种新的治疗策略的临床应用所需的动物模型提供关键知识。这些研究还将促进我们对正常和病变条件下视网膜回路和功能的了解，并为视网膜基础研究开发新的工具。

DESCRIPTION (provided by applicant): The severe loss of photoreceptor cells in retinal degenerative diseases could result in partial or complete blindness. Currently, once the photoreceptors are lost, there is no effective treatment available for restoring lost vision. We are exploring a novel strategy of genetically converting light-insensitive second- or third-order retinal neurons into photosensitive cells, thus imparting light-sensitivity to retinas that lack photoreceptors. Proof-of-concept studies have demonstrated the feasibility of the functional expression of channelrhodopsin-2 (ChR2) and halorhodopsin (HaloR) in inner retinal neurons and resulting restoration of ON and OFF light responses in the retina of a mouse model with retinal degeneration. The objective of this proposal will continue the proof-of-principle studies in rodent models to address issues that are important for developing this treatment strategy for clinical applications. Specifically, we will study the long-term expression of HaloR in inner retinal neurons in vivo and investigate the underlying mechanism(s) of ChR2 and HaloR-mediated light responses in retinal neurons. We will also explore targeted expression of ChR2 and HaloR to specific population(s) of inner retinal neurons and/or sub cellular compartments of retinal ganglion cells. Furthermore, we will investigate the ChR2 and HaloR-mediated light response properties from the targeted cells and their downstream neurons in normal and retinal degenerative mice. Our long-term goal is to develop a novel strategy for treating or curing blindness caused by retinal degeneration. The proposed studies will provide critical knowledge in animal models required for advancing this new treatment strategy to clinical applications. The studies will also advance our knowledge of retinal circuitry and functions under normal and diseased conditions as well as develop new tools for basic retinal research. PUBLIC HEALTH RELEVANCE: Our goal is to develop a novel strategy for treating or curing blindness caused by retinal degeneration. If successful, this strategy could be potentially used to treat or cure all common blindness caused by photoreceptor loss.