APC Microbiome Ireland, University College Cork, Cork, Ireland.
Pharmacodelivery Group, School of Pharmacy, University College Cork, Cork, Ireland.
Eur J Neurosci. 2023 Jan;57(2):233-241. doi: 10.1111/ejn.15878. Epub 2022 Dec 9.
The gut microbiota communicates with the brain through several pathways including the vagus nerve, immune system, microbial metabolites and through the endocrine system. Pathways along the humoral/immune gut microbiota-brain axis are composed of a series of vascular and epithelial barriers including the intestinal epithelial barrier, gut-vascular barrier, blood-brain barrier and blood-cerebrospinal fluid barrier. Of these barriers, the relationship between the gut microbiota and blood-cerebrospinal fluid barrier is yet to be fully defined. Here, using a germ-free mouse model, we aimed to assess the relationship between the gut microbiota and the integrity of the blood-cerebrospinal fluid barrier, which is localized to the choroid plexus epithelium. Using confocal microscopy, we visualized the tight junction protein zonula occludens-1, an integral aspect of choroid plexus integrity, as well as the choroid plexus fenestrated capillaries. Quantification of tight junction proteins via network analysis led to the observation that there was a decrease in the zonula occludens-1 network organization in germ-free mice; however, we did not observe any differences in capillary structure. Taken together, these data indicate that the blood-cerebrospinal fluid barrier is another barrier along the gut microbiota-brain axis. Future studies are required to elucidate its relative contribution in signalling from microbiota to the brain.
肠道微生物群通过几种途径与大脑进行通讯，包括迷走神经、免疫系统、微生物代谢物以及内分泌系统。沿着体液/免疫肠道微生物群-大脑轴的途径由一系列血管和上皮屏障组成，包括肠道上皮屏障、肠道-血管屏障、血脑屏障和血脑脊液屏障。在这些屏障中，肠道微生物群与血脑脊液屏障之间的关系尚未完全确定。在这里，我们使用无菌小鼠模型，旨在评估肠道微生物群与定位于脉络丛上皮的血脑脊液屏障完整性之间的关系。使用共聚焦显微镜，我们可视化了紧密连接蛋白紧密连接蛋白-1，这是脉络丛完整性的一个组成部分，以及脉络丛有孔毛细血管。通过网络分析对紧密连接蛋白进行定量，观察到无菌小鼠中紧密连接蛋白-1网络组织减少；然而，我们没有观察到毛细血管结构有任何差异。总之，这些数据表明血脑脊液屏障是肠道微生物群-大脑轴的另一个屏障。需要进一步的研究来阐明其在微生物群向大脑发出信号中的相对贡献。
