The Novel Role of Cilia in Astrocyte Sevelopment

项目摘要 星形胶质细胞是脑中最丰富的胶质细胞，是神经回路形成和神经元再生所必需的。 功能星形胶质细胞在大脑发育中起着不可或缺的作用，但我们对星形胶质细胞的基本理解是， 星形胶质细胞是如何发育的，这与我们对神经元发育的认识相脱节。为了发育，星形胶质细胞必须以 适当的时间，遗传分化，形态成熟。星形胶质细胞功能障碍导致 病理学的几种神经发育障碍，但这些机制知之甚少。两 神经元和星形胶质细胞具有初级纤毛，一种细长的微管突起， 细胞的专门信号中心。纤毛是神经元发育的关键调节器。但尽管 虽然星形胶质细胞具有初级纤毛，但星形胶质细胞纤毛的功能仍然未知。破坏纤毛会导致 这类疾病被称为纤毛病，通常导致一系列神经异常。我们必须 建立对星形胶质细胞纤毛的基本理解，因为它们可能有助于这种 神经发育疾病我研究的目标是创造角色的基础知识， 纤毛在星形胶质细胞发育中的作用我的初步数据表明，星形胶质细胞纤毛是必要的， 星形胶质细胞发育的各个阶段。星形胶质细胞纤毛的缺失导致增殖改变，异常细胞增殖， 形态学和发育星形胶质细胞基因表达的破坏。因此，我假设 星形胶质细胞纤毛对于调节星形胶质细胞增殖和分化是至关重要的。本项目旨在：1）确定 纤毛如何调节星形胶质细胞增殖和2）确定纤毛在星形胶质细胞分化中的作用。我会用 小鼠模型，在不同的时间点遗传消融纤毛，特别是在星形胶质细胞中，以研究 星形胶质细胞发育的不同阶段对纤毛的需求。我将确定纤毛是否调节 星形胶质细胞增殖的时间和速率。然后，为了进一步确定纤毛如何调节增殖，我将监测 细胞周期进程接下来，我将通过进行一项研究来确定纤毛是否是星形胶质细胞分化所必需的。 星形胶质细胞大小、间距和分支特征的形态学分析。最后，我将进行一次 转录组学分析以确定纤毛是否调节发育中的星形胶质细胞的遗传程序。我会 还在细胞水平上检查星形胶质细胞的转录表达，以确定纤毛是否影响 分化的特定群体的皮质星形胶质细胞。这些实验将揭示新的 星形胶质细胞纤毛的功能，并为纤毛信号在星形胶质细胞发育中的作用奠定基础。 这项工作将增加有关星形胶质细胞纤毛的基础知识，以及星形胶质细胞如何发展，以改善 我们对星形胶质细胞在神经发育疾病中的作用的理解。

PROJECT SUMMARY Astrocytes are the most abundant glial cell in the brain and are essential for neural circuit formation and neuron function. Astrocytes have an indispensable role in the developing brain, yet our fundamental understanding of how astrocytes develop trails our knowledge of neuron development. To develop, astrocytes must proliferate at the proper time, genetically differentiate, and morphologically mature. Astrocyte dysfunction contributes to the pathology of several neurodevelopmental disorders, yet these mechanisms are poorly understood. Both neurons and astrocytes possess a primary cilium, a slender microtubule projection, that serves as a specialized signaling center for the cell. Cilia are critical regulators of neuron development. However, despite astrocytes having a primary cilium, the function of astrocyte cilia remains unknown. Disruptions to cilia result in a class of disorders termed ciliopathies that often result in a spectrum of neurological abnormalities. We must establish a fundamental understanding of astrocyte cilia because it is likely that they contribute to such neurodevelopmental diseases. The goal of my research is to create foundational knowledge of the roles that cilia play in astrocyte development. My preliminary data indicate that astrocyte cilia are necessary for several stages of astrocyte development. Loss of astrocyte cilia results in altered proliferation, abnormal cellular morphology, and disrupted expression of developmental astrocyte genes. Therefore, I hypothesize that astrocyte cilia are critical to regulate astrocyte proliferation and differentiation. This project aims to 1) determine how cilia regulate astrocyte proliferation and 2) define the role of cilia in astrocyte differentiation. I will use mouse models to genetically ablate cilia at distinct timepoints, specifically in astrocytes, to investigate the requirements of cilia at different stages of astrocyte development. I will determine whether cilia regulate the timing and rate of astrocyte proliferation. Then, to further define how cilia regulate proliferation, I will monitor cell cycle progression. Next, I will define whether cilia are required for astrocyte differentiation by conducting a morphological analysis of astrocyte size, spacing, and branching features. Finally, I will conduct a transcriptomics analysis to determine whether cilia regulate the genetic program of developing astrocytes. I will also examine astrocyte transcriptional expression at the cellular level to define whether cilia impact differentiation in specific populations of cortical astrocytes. The proposed experiments will reveal novel functions of astrocyte cilia and establish a foundation for the roles of ciliary signaling in astrocyte development. This work will increase fundamental knowledge about astrocyte cilia and how astrocytes develop to improve our understanding of astrocyte contribution to neurodevelopmental diseases.