Elucidating the Role of Sonic Hedgehog Signaling in Cells Along the Astrocyte Lineage

项目总结 这项提议的目标是确定分子上不同的祖细胞是否会导致局部 星形细胞多样性。据估计，星形胶质细胞占大脑中细胞的40%，而且还在生长。 现在有证据表明，这些细胞具有不同的表型和分子特征。 然而，在我们对这些明显特征是如何产生的理解中，仍然存在很大的差距。本研究 重点介绍了分子信号通路Sonic hedgehog(Shh)的作用，Sonic hedgehog(Shh)区分了 围产期神经胶质前体细胞在前脑中的数量。命运映射实验表明，这些 祖细胞产生一半的皮质星形胶质细胞，这表明大脑皮质有星形胶质细胞。 来自多个血统。Shh信号在星形胶质细胞发育中的确切作用尚不清楚。 本研究将分子遗传学工具与高分辨率成像和三维重建技术相结合。 单细胞，结合RNAseq和生物信息学分析，以解决Shh信号在 确定星形胶质细胞的谱系特异性表型和分子特征。我们将首先确定 前体细胞负责Shh介导的星形胶质细胞的产生并确定细胞的独特特征 在这个血统中。然后我们将与RNAseq和生物信息学一起应用功能丧失策略 分析Shh信号在星形胶质细胞发育和分子识别中的作用。最后，我们 将使用细胞消融方法来确定来源于Shh的细胞的功能意义 血统。这项研究将促进我们对脑内星形胶质细胞多样性的理解，并为新的 Shh信号在细胞和脑发育中的作用。

PROJECT SUMMARY The goal of this proposal is to determine whether molecularly distinct progenitor cells give rise to local astrocyte diversity. Astrocytes are estimated to comprise up to 40% of cells in the brain and growing evidence now shows that these cells possess diverse phenotypic and molecular characteristics. Nevertheless, large gaps remain in our understanding of how such distinct characteristics arise. This study focuses on the role of the molecular signaling pathway, Sonic hedgehog (Shh), which distinguishes a population of perinatal glial progenitor cells in the forebrain. Fate mapping experiments show that these progenitors generate half the population of cortical astrocytes, suggesting that the cortex harbors astrocytes from multiple lineages. The precise role of Shh signaling in astrocyte development is not well understood. This study applies molecular genetic tools together with high resolution imaging and 3D reconstruction of single cells, together with RNASeq and bioinformatic analysis to address the role of Shh signaling in defining lineage-specific phenotypic and molecular characteristics of astrocytes. We will first identify the progenitor cell responsible for Shh-mediated astrocyte production and define unique characteristics of cells within this lineage. We will then apply loss of function strategies together with RNASeq and bioinformatic analysis to interrogate the role of Shh signaling in astrocyte development and molecular identity. Finally, we will use a cellular ablation approach to determine the functional significance of cells derived from the Shh lineage. This study will advance our understanding of astrocyte diversity in the brain and illuminate novel roles for Shh signaling in cell and brain development.