Ependymal cells in adulthood

室管膜细胞是中枢神经系统的4种胶质细胞类型之一。它们是终生维持的上皮性脑屏障细胞，排列在整个脑室系统和椎管内。它们是中枢神经系统中主要面向脑脊液(CSF)的细胞，具有感知脑脊液动力学并调节其分布的能力。根据其形态特征，已知的三种主要亚型被预测具有不同的功能，但这些细胞是如何维持的、它们具有的功能程度以及它们如何调节大脑功能的不同机制仍有待确定。作为一名早期的职业研究人员，我的实验室正在开发一个以了解室管膜细胞生物学为中心的长期项目，包括开发使用体内、体外和体外分析来研究室管膜细胞的先进技术。在目前的提案中，我的短期目标集中在询问体内的小鼠室管膜细胞，以使用转基因命运映射策略来评估维持机制；使用先进的生物信息学来表征它们的多样性；以及使用可诱导的室管膜细胞KO系统来询问这些细胞在维持大脑功能中的明确角色。目的1：评估室管膜细胞在成年期是如何维持的，大多数胶质细胞在一生中都被前体细胞取代，但在正常情况下速度非常慢。为了确定这是否发生在室管膜细胞维持的背景下，我们将使用小鼠命运映射模型永久标记室管膜细胞，以追踪这些细胞是长期维持、数量增加还是丢失。这将为室管膜细胞的维持提供洞察力。目的2：研究成年期室管膜细胞的异质性，对驱动室管膜细胞功能分化的转录谱知之甚少。为了解决这个问题，我们将进行先进的生物信息学分析，评估由室管膜细胞组成的单细胞数据集，并使用组织切片进行原位杂交来验证结果。这将提供对室管膜细胞异质性程度的洞察，并提供关于这些细胞具有的一系列功能的公正建议。目的：评估室管膜细胞在成年期的功能。室管膜细胞上有运动的纤毛，这些纤毛的跳动产生定向的液体运动，但室管膜细胞介导的脑脊液运动在成年期的重要性尚未被评估。我们将在纤毛基因CDCC39的KO之后询问这一点，该基因只在有牙线的小鼠的室管膜细胞中。研究这一点将为室管膜细胞如何调节脑脊液运动提供关键的见解，以及这是否对维持大脑内环境平衡重要。我们的结果将促进我们对成人室管膜细胞生物学的理解，以及它们对维持大脑功能的重要性。

Ependymal cells are one of 4 glia cell types in the central nervous system (CNS). They are epithelial brain barrier cells that are maintained throughout life, and line the entire brain ventricular system and spinal canal. They are the major cerebral spinal fluid (CSF) facing cell of the CNS with the capacity to sense CSF dynamics and regulate its distribution. There are 3 major known subtypes that are predicted to have diverse functions based on their morphological features, yet it remains to be determined how these cells are maintained; the extent of functions they have, as well as the diverse mechanisms underlying how they regulate brain function. As an early career investigator, my lab is developing a long-term program centred around understanding ependymal cell biology including the development of advanced techniques for studying ependymal cells using in vivo, ex vivo and in vitro assays. In the current proposal, my short-term objectives focus on interrogating mouse ependymal cells in vivo to assess the mechanisms of maintenance using a transgenic fate mapping strategy; characterize their diversity using advanced bioinformatics; as well as interrogate a defined role for these cells in maintaining brain function using an inducible ependymal cell KO system. AIM 1: Assess how ependymal cells are maintained in adulthood Most glia cells are replaced by precursor cells throughout life, but at very slow rates in normal circumstances. To establish whether this occurs in the context of ependymal cell maintenance, we will use a mouse fate mapping model to permanently label ependymal cells to track whether these cells are maintained long-term, increase in number, or are lost. This will provide insights into how ependymal cells are maintained. AIM 2: Characterize the heterogeneity of ependymal cells in adulthood Little is known about the transcriptional profile that drives divergent ependymal cell roles. To address this question, we will perform advanced bioinformatic analysis assessing single cell datasets composed of ependymal cells, and validate findings using tissue sections for in situ hybridization. This will provide insights into the degree of ependymal cell heterogeneity as well as provide unbiased suggestions as to repertoire of functions that these cells have. AIM 3: Assess the function of ependymal cell in adulthood Ependymal cells are equipped with motile cilia, and the beating of these cilia generates directional fluid movement, yet the importance of ependymal cell-mediated CSF movement in adulthood has not been assessed. We will interrogate this following the KO of a cilia gene, CDCC39, only in ependymal cells in floxed mice. Studying this will provide critical insights into how ependymal cells regulate CSF movement and whether this is important for maintaining brain homeostasis. Our outcomes will advance our understanding of adult ependymal cell biology, and their importance for maintaining brain function.