A large portion of the astrocyte proteome is dedicated to perivascular endfeet, including critical components of the electron transport chain
A large portion of the astrocyte proteome is dedicated to perivascular endfeet, including critical components of the electron transport chain
复制标题
DOI：
10.1177/0271678x211004182
复制
发表时间：
2021-04-04
影响因子：
6.3
通讯作者：
Simard, J. Marc
中科院分区：
文献类型：
--
作者：
Stokum, Jesse A.;Shim, Bosung;Simard, J. Marc
血管周围星形胶质细胞尾足是一种特殊的、扩散受限的亚细胞区室，完全包裹着脑血管系统。尽管它们无处不在，但对终足生理学的详细了解仍然难以捉摸，部分原因是对区分终足和更大星形胶质细胞体的蛋白质的了解有限。在这里，我们开发了一种从脑组织中分离星形胶质细胞末端足的技术，该技术用于研究末端足蛋白质组与星形胶质细胞体细胞的比较。在我们的方法中，从小鼠大脑中分离并解离保留其终足突起的脑微血管，随后使用基于抗体的柱星形胶质细胞分离试剂盒回收终足。我们的研究结果将已知的尾足富集蛋白质组从 10 种扩大到 516 种，其中包含整个检测到的星形胶质细胞蛋白质组的 1/5 以上。许多关键的电子传递链蛋白仅在末端表达，而参与糖原储存的酶则分布到胞体，表明亚细胞代谢区室化。足尾蛋白质组还包括许多蛋白质，虽然已知这些蛋白质对血脑屏障功能有重要贡献，但以前并不知道这些蛋白质定位于足尾。我们的研究结果强调了足底的重要性，并提出了研究足底功能的新途径。
The perivascular astrocyte endfoot is a specialized and diffusion-limited subcellular compartment that fully ensheathes the cerebral vasculature. Despite their ubiquitous presence, a detailed understanding of endfoot physiology remains elusive, in part due to a limited understanding of the proteins that distinguish the endfoot from the greater astrocyte body. Here, we developed a technique to isolate astrocyte endfeet from brain tissue, which was used to study the endfoot proteome in comparison to the astrocyte somata. In our approach, brain microvessels, which retain their endfoot processes, were isolated from mouse brain and dissociated, whereupon endfeet were recovered using an antibody-based column astrocyte isolation kit. Our findings expand the known set of proteins enriched at the endfoot from 10 to 516, which comprised more than 1/5th of the entire detected astrocyte proteome. Numerous critical electron transport chain proteins were expressed only at the endfeet, while enzymes involved in glycogen storage were distributed to the somata, indicating subcellular metabolic compartmentalization. The endfoot proteome also included numerous proteins that, while known to have important contributions to blood-brain barrier function, were not previously known to localize to the endfoot. Our findings highlight the importance of the endfoot and suggest new routes of investigation into endfoot function.