Local Proliferation of Glia and their Interaction with Blood Vessels

项目摘要/摘要 我的长期目标是阐明神经胶质细胞发育的机制。此应用程序的重点是 表征大脑皮层中星形胶质细胞的局部增殖及其机制 在出生后阶段与血管的相互作用。 在出生后的第2和第3周，血管密度和胶质细胞数量都增加了 在啮齿动物脑中约为4倍。目前还不清楚大量的星形胶质细胞来自哪里，以及它们是如何形成的。 与血管相互作用。我的初步数据显示，出生后星形胶质细胞的局部增殖广泛存在于 分布在大脑皮层的不同层，这些星形胶质细胞保留它们的终足（血管周围 星形胶质细胞的突起）与血管同时进入有丝分裂阶段。因此，我推测， 星形胶质细胞的增殖是皮质星形胶质细胞的主要来源，皮质星形胶质细胞有助于终足的形成。 出生后的大脑为了解决这个假设，我提出了两个具体的目标：（1）表征局部增殖 研究星形胶质细胞在大脑皮层中的命运和功能;（2）阐明星形胶质细胞在大脑皮层中的作用机制。 由局部产生的星形胶质细胞介导的血管周围的终足形成。我建立了两个 通过遗传编码的荧光标记物稀疏标记星形胶质细胞的转基因小鼠品系组 用前所未有的分辨率，沿着的是我发明的标记和记录分裂细胞的方法。我是 因此，独特地准备进行这项新颖的研究。 在K99指导阶段（第1年和第2年）提出的研究集中在建立 活动物中胶质细胞增殖的逆转录病毒标记和成像方法，将用 Lily Jan博士的监督。R 00独立阶段（3至5年）将侧重于表征 通过局部增殖产生的星形胶质细胞的功能，以及它们与 血管这项研究是创新的，因为它将提供第一个直接证据， 出生后大脑皮层星形胶质细胞的局部增殖，并显示它们如何整合到神经胶质网络中 并形成具有血管的端足结构。

Project Abstract/Summary My long-term goal is to elucidate mechanisms for glial development. The focus of this application is to characterize local proliferation of astrocytes in the cerebral cortex and the mechanism underlying their interaction with blood vessels at the postnatal stage. During postnatal weeks 2 and 3, the density of blood vessels and the number of glial cells both increase by ~4 fold in the rodent brain. It is still unclear where the large number of astrocytes come from and how they interact with blood vessels. My preliminary data show that postnatal local proliferation of astrocytes is widely distributed in different layers of the cerebral cortex, and these astrocytes retain their endfeet (perivascular processes of astrocytes) with blood vessels while they enter mitotic stages. I thus hypothesize that local prolifaration of astrocytes is a main source of cortical astrocytes that contribute to endfoot formation in the postnatal brain. To address the hypothesis, I propose two specific aims: (1) Characterize local proliferation of astrocytes and their fate and function in the cerebral cortex; (2) Elucidate the mechanism underlying endfoot formation around blood vessels mediated by locally generated astrocytes. I have established two groups of transgenic mouse lines to sparsely label astrocytes via genetically encoded fluorescent markers with unprecedented resolution, along with methods I developed to label and record dividing cells. I am therefore uniquely poised to undertake this novel study. Research proposed in the K99 Mentored phase (year 1 and 2) is concentrated on the establishment of methods for retroviral labeling and imaging of glial proliferation in live animals, which will be carried out with the supervision of Dr. Lily Jan. The R00 Independent phase (years 3 to 5) will focus on characterizing the function of astrocytes generated via local proliferation, and the mechanism underlying their interaction with blood vessels. The proposed research is innovative because it will provide the first direct evidence of postnatal local proliferation of astrocytes in cerebral cortex and show how they integrate into glial network and form endfoot structures with blood vessels.