Elucidating the molecular and cellular mechanisms underlying cone survival in the peripheral retina in mouse models of Retinitis Pigmentosa

项目摘要 视网膜色素变性（RP）是一种遗传性视网膜疾病，在全世界每4,000人中就有1人患病。疾病 最初进展由视杆细胞特异性基因突变引起的视杆细胞变性，尽管 在这种疾病中，不同基因中的不同突变会聚在相同的视杆细胞变性表型上。 然而，正是随后的视锥细胞变性导致日光色觉丧失， 最终，降低了大多数患者的生活质量。虽然基因治疗是用一种 功能性复制已经成功，鉴于突变和基因的异质性，很难治疗所有RP 以核燃料棒为目标。相反，在视杆细胞变性后保留视锥细胞的通用疗法可能导致 更全面的治疗方案尽管取得了进展，但这种继发性的分子机制 视锥细胞变性仍不清楚。在RP小鼠模型中，视杆细胞变性后， 死亡，但有趣的是，视网膜周边的视锥细胞可以长期存活。这项研究的目标是 是了解小鼠模型中外周视锥细胞存活的分子和细胞机制， Rp.在本补助金的辅导阶段（K99阶段），可能是充分的（目标1）和/或必要的因素 (Aim 2）通过细胞类型特异性RNA测序，体内视网膜电穿孔， 和时间调控基因缺失。在该补助金的独立阶段（R 00阶段），因果关系 将探索血视网膜屏障破坏和视锥变性之间的关系（目的3）。完成 提出的目标将导致确定的关键调节锥存活的小鼠模型的RP。 此外，我们可以确定，为第一次，BRB崩溃和二次锥之间的因果关系 死亡，打开新的细胞靶点，以防止RP患者的视锥细胞丢失。从长远来看， 在这个补助金可以成为回答问题的基石，关于如何，一般来说，神经元和其他 支持细胞在整个中枢神经系统的神经变性疾病中退化。受指导者 该赠款的第一阶段是在康斯坦斯·切普科博士的指导下进行的，他的实验室开发了许多 多年来，科学家们一直致力于在体内对视网膜进行遗传操作，并发现了基因调控网络。 潜在的视网膜细胞类型规范。围绕着哈佛的Cepko实验室的科学环境 医学院为职业发展提供了宝贵的机会，帮助建立一个坚实的基础， 研究视网膜变性的分子机制。

Project Summary Retinitis Pigmentosa (RP) is an inherited retinal disease afflicting 1 in 4,000 people worldwide. The disease progresses initially by rod photoreceptor degeneration caused by mutations in rod-specific genes, although different mutations in different genes converge upon the same rod degeneration phenotype in this disease. However, it is the subsequent cone photoreceptor degeneration that causes loss in daylight color vision and ultimately, diminishing quality of life for most patients. While gene therapy to replace a mutated gene with a functional copy has been successful, given the heterogeneity in mutations and genes, it is difficult to treat all RP cases by targeting the rods. Instead, a generic therapy to preserve the cones upon rod degeneration may lead to a more comprehensive therapeutic option. Despite progress, the molecular mechanism for this secondary cone degeneration remains unclear. In mouse models of RP, the cones in the central retina degenerate after rod death, but interestingly, the cones in the peripheral retina survive long-term. The goal of this proposed research is to understand the molecular and cellular mechanisms underlying peripheral cone survival in mouse models of RP. During the mentored phase of this grant (K99 phase), factors that may be sufficient (Aim 1) and/or necessary (Aim 2) for cone survival will be elucidated by cell type specific RNA sequencing, in vivo retinal electroporation, and temporally-regulated gene deletion. During the independent phase of this grant (R00 phase), the causal relationship between blood-retina-barrier breakdown and cone degeneration will be explored (Aim 3). Completion of the proposed aims will lead to identification of key regulators of cone survival in mouse models of RP. Moreover, we may identify, for the first time, a causal relationship between BRB breakdown and secondary cone death, opening new cellular targets to prevent cone loss in patients with RP. Long-term, the approaches outlined in this grant can become the cornerstone for answering questions regarding how, in general, neurons and other supporting cells degenerate in neurodegenerative disorders across the central nervous system. The mentored phase of this grant is conducted under the guidance of Dr. Constance Cepko, whose lab has developed many techniques over the years to genetically manipulate the retina in vivo and discovered gene regulatory networks underlying retinal cell type specification. The scientific environment that surrounds the Cepko Lab at Harvard Medical School offers valuable opportunities for career development, helping to build a strong foundation for an independent career investigating the molecular mechanisms of retinal degeneration.