美国南卡罗莱纳医科大学Andy Y. Shih研究团队取得最新进展。他们揭示脑毛细血管周细胞对血流有明显而缓慢的影响。相关论文于2021年2月18日发表于《自然-神经科学》。

使用双光子显微镜在体内观察和操作脑毛细血管周细胞，他们发现它们的光遗传学刺激降低了管腔直径和血流量，但动力学上比壁上细胞和上游小动脉和毛细血管前小动脉的类似刺激慢。这种缓慢的血管收缩被临床使用的血管扩张药fasudil抑制，后者是一种Rho激酶抑制剂，可阻断收缩机制。高碳酸血症诱导的扩张后，毛细血管周细胞收缩到基线的速度也较慢，而光遗传学引起的血管收缩后，毛细血管的细胞扩张到基线的速度也较慢。

在缺乏周细胞接触的毛细血管中，单个毛细血管周细胞的光学消融导致持续的局部扩张和选择性地使血细胞通量增加一倍。这些数据表明毛细血管周细胞有助于基础血流阻力和整个大脑血流的缓慢调节。

据了解，大脑的大部分脉管系统都是由毛细血管周细胞排列的复杂毛细血管网络组成。但是，尚不清楚毛细血管周细胞是否影响血流。

附：英文原文

Title: Brain capillary pericytes exert a substantial but slow influence on blood flow

Author: David A. Hartmann, Andre-Anne Berthiaume, Roger I. Grant, Sarah A. Harrill, Tegan Koski, Taryn Tieu, Konnor P. McDowell, Anna V. Faino, Abigail L. Kelly, Andy Y. Shih

Issue&Volume: 2021-02-18

Abstract: The majority of the brain’s vasculature is composed of intricate capillary networks lined by capillary pericytes. However, it remains unclear whether capillary pericytes influence blood flow. Using two-photon microscopy to observe and manipulate brain capillary pericytes in vivo, we find that their optogenetic stimulation decreases lumen diameter and blood flow, but with slower kinetics than similar stimulation of mural cells on upstream pial and precapillary arterioles. This slow vasoconstriction was inhibited by the clinically used vasodilator fasudil, a Rho-kinase inhibitor that blocks contractile machinery. Capillary pericytes were also slower to constrict back to baseline following hypercapnia-induced dilation, and slower to dilate towards baseline following optogenetically induced vasoconstriction. Optical ablation of single capillary pericytes led to sustained local dilation and a doubling of blood cell flux selectively in capillaries lacking pericyte contact. These data indicate that capillary pericytes contribute to basal blood flow resistance and slow modulation of blood flow throughout the brain.

DOI: 10.1038/s41593-020-00793-2

Source: https://www.nature.com/articles/s41593-020-00793-2