Okamoto Akihiro, Fujii Rena, Yoshimura Ryoichi, Miyata Seiji
Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
Neurosci Lett. 2022 May 14;779:136633. doi: 10.1016/j.neulet.2022.136633. Epub 2022 Apr 13.
Tanycytes are specialized ependymal cells lining the ventricular spaces of the adult brain and thereby provide an interface between the cerebrospinal fluid (CSF) and brain parenchyma. They act as energy homeostasis, neuroendocrine regulation, and CSF-brain barrier; however, their functional significance in CSF-brain communication currently remains unknown. In the present study, we investigated the presence of tanycytic transcytosis using fluorescent tracers; a GM1 ligand, cholera toxin B (CTB), and a mannose-6-phosphate/insulin-like growth factor-Ⅱ receptor ligand, wheat germ agglutinin (WGA). Both CTB and WGA were incorporated by tanycytes and then released into brain parenchyma in the circumventricular organs such as the organum vasculosum laminae terminalis, subfornical organ, and median eminence, arcuate nucleus, and medullary central canal. Incorporated fluorescent CTB and WGA were released from tanycytes to distribute at neuronal somata. These results indicate that tanycytes of all examined brain regions possess the transport capability of macromolecules from CSF to brain neurons.
室管膜胶质细胞是衬于成人大脑脑室腔的特化室管膜细胞，从而在脑脊液（CSF）与脑实质之间提供一个界面。它们在能量稳态、神经内分泌调节和脑脊液-脑屏障中发挥作用；然而，它们在脑脊液-脑通讯中的功能意义目前仍不清楚。在本研究中，我们使用荧光示踪剂研究了室管膜胶质细胞转胞吞作用的存在；一种GM1配体霍乱毒素B（CTB）和一种甘露糖-6-磷酸/胰岛素样生长因子Ⅱ受体配体麦胚凝集素（WGA）。CTB和WGA都被室管膜胶质细胞摄取，然后释放到脑室周器官的脑实质中，如终板血管器、穹窿下器、正中隆起、弓状核和延髓中央管。摄取的荧光CTB和WGA从室管膜胶质细胞释放出来，分布于神经元胞体。这些结果表明，所有检测脑区的室管膜胶质细胞都具有将大分子从脑脊液转运到脑神经元的能力。
