Uncovering the molecular identity of retinal cell types, and their responses to nerve injury using single-cell transcriptomics

摘要 中枢神经系统（CNS）的神经元在历史上已被分类为离散的“类型”，其基于 结构、生理反应、连接模式和分子概况。Heteroantibodies可以有其他 结果-例如，最近的研究发现，视网膜中的一些神经元类型比视网膜中的神经元类型更有弹性。 其他类型的视神经损伤，导致视力不可恢复的损害的事件。 我的项目结合了尖端的单细胞基因组技术，先进的计算数据分析， 分子工具来全面定义神经元类型的异质性，将分子定义与 组织学，并探讨神经损伤过程中这种异质性的功能后果。我将集中在一个 这是一个易于处理的系统，即老鼠的视网膜，它将视觉反应传递给大脑。它和任何 大脑的其他区域（包含约120种神经元类型），但受益于具有紧凑，可访问的 结构和实验工具使其特别适合于详细的分析。基于我之前的 博士后工作，这个项目将， 1)完成小鼠视网膜的普查，这将是第一次为任何中枢神经系统区域，通过推断分子 分类的两个最异质的类（无长突和神经节细胞）从收集的数据，使用 高通量单细胞RNA测序。使用鼠标普查，启动一个类似的映射， 猕猴视网膜，这是很难进入实验，但与人类的重要特征， 在老鼠身上没有。 2)对视神经损伤视网膜中细胞类型特异性反应进行系统研究。这 通常会导致视网膜神经节细胞（RGC）的快速，刻板的死亡，但我的同事最近的一项研究表明， 报告指出，某些研资局类别的适应能力较其他类别为强。在这里，使用1）作为资源，我将确定 细胞内在和外在的因素，使这些RGC类型具有弹性。 3)细胞类型的选择性恢复现在被认为是青光眼和中风等疾病的特征。 因此，治疗需要迎合不同的细胞类型。为了了解更多，并得出一般原则，我将 检查已知的治疗干预对不同RGC类型生存的影响， 潜在的分子反应，在视神经损伤模型。 总之，我的项目将获得大量的神经元异质性的分子信息， 小鼠和猕猴视网膜以及中枢神经系统损伤后细胞类型选择性恢复的一般原则 小鼠这项工作的经验教训将为在交通不便的地区进行类似的研究提供有价值的指导。 大脑（例如大脑皮层）。

ABSTRACT Neurons of the central nervous system (CNS) have been historically categorized into discrete "types" based on structure, physiological responses, connectivity patterns, and molecular profiles. Heterogeneity can have other consequences- e.g. recent studies have found that some neuronal types in the retina are more resilient than other types to optic nerve injury, an event that leads to irrecoverable damage in vision. My project combines cutting-edge single-cell genomic technologies, advanced computational data analysis and molecular tools to define heterogeneity of neuronal types comprehensively, to connect molecular definitions to histology, and explore the functional consequences of this heterogeneity during nerve injury. I will focus on a tractable system, the mouse retina, which communicates visual responses to the brain. It is as complex as any other region of the brain (containing ~120 neuronal types), but benefits from having a compact, accessible structure, and experimental tools make it especially suited for detailed analyses. Building on my previous postdoctoral work, this project will, 1) Complete the census of the mouse retina, which will the first for any CNS region, by inferring molecular taxonomies of two of its most heterogenous classes (amacrines and ganglion cells) from data collected using high-throughput single-cell RNA-sequencing. Using the mouse census, initiate a similar mapping of the macaque retina, which is harder to access experimentally, but shares important features with humans that are absent in mice. 2) Conduct a systematic investigation of cell-type specific responses in the retina to optic nerve injury. This usually leads to a rapid, stereotypic death of retinal ganglion cells (RGCs), but a recent study by my colleagues reported that some RGC types are more resilient than others. Here, using 1) as a resource, I will identify factors, cell intrinsic and extrinsic, that make these RGC types resilient. 3) Selective resilience of cell types is now recognized as a feature of diseases like glaucoma and stroke. Therapies therefore need to cater to different cell types. To learn more, and derive general principles, I will examine the impact of known therapeutic interventions on the survival of different RGC types, and the underlying molecular responses, within the optic nerve injury model. Taken together, my project will derive substantial molecular information underlying neuronal heterogeneity in the mouse and macaque retina and general principles for cell-type selective resilience following CNS injury in mice. The lessons from this work will provide valuable guidance for similar studies in less accessible regions of the brain (e.g. cerebral cortex).