Turnover of rat brain perivascular cells
Turnover of rat brain perivascular cells
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DOI：
10.1006/exnr.2000.7618
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发表时间：
2001-04-01
影响因子：
5.3
通讯作者：
Nitsch, R
中科院分区：
文献类型：
--
作者：
Bechmann, I;Kwidzinski, E;Nitsch, R
大脑血管周围空间含有一群表现出高吞噬能力的细胞。因此，这些细胞可以通过心室内注射示踪剂来标记。血液和大脑之间界面的这种血管周围细胞被认为属于单核细胞/巨噬细胞谱系并参与抗原呈递。目前，尚不清楚这些细胞是否通过进入和离开血液而经历持续的周转。据报道，使用骨髓嵌合动物，供体巨噬细胞迁移到大脑血管周围空间。另一方面，向非移植动物脑内注射印度墨水后，注射两年后仍然发现墨水标记的血管周围细胞，表明该细胞库具有高度稳定性。因此，在嵌合体中观察到的血管周围细胞的更新可能是骨髓移植的结果，而不是生理现象。为了解决这个问题，我们通过应用骨髓移植以外的技术，（i）连续注射不同的示踪剂和（ii）从血液中离体分离巨噬细胞，细胞标记并重新注射到同一动物中以避免MHC不匹配，监测巨噬细胞从头侵入表面健康的成年大鼠的血管周围空间。这两种方法都揭示了巨噬细胞从头开始侵入血管周围空间，但没有侵入脑实质，这使得血管周围细胞在大脑中形成稳定的巨噬细胞群的概念站不住脚。因此，正常成年大鼠的大脑血管周围空间受到血源性巨噬细胞的永久免疫监视。 (C) 2001 年学术出版社。
Brain perivascular spaces harbor a population of cells which exhibit high phagocytic capacity. Therefore, these cells can be labeled by intraventricular injection of tracers. Such perivascular cells at the interface between blood and brain are believed to belong to the monocyte/macrophage lineage and to be involved in antigen presentation. Currently, it is unclear whether these cells undergo a continuous turnover by entering and leaving the bloodstream. Using bone-marrow-chimeric animals, migration of donor macrophages into brain perivascular spaces has been reported. On the other hand, following intracerebral injection of india ink into nontransplanted animals, ink-labeled perivascular cells were still found 2 years after injection, suggesting a high stability of this cell pool. Thus, the turnover of perivascular cells observed in chimeras might be a result of bone marrow transplantation rather than a physiological occurrence. To address this issue, we monitored de novo invasion of macrophages into perivascular spaces of apparently healthy adult rats by applying techniques other than bone marrow transplantation, (i) consecutive injections of different tracers and (ii) ex vivo isolation of macrophages from the blood, cell labeling, and reinjection into the same animal to avoid MHC mismatch. Both approaches revealed vivid de novo invasion of macrophages into perivascular spaces, but not into brain parenchyma, rendering untenable the concept of perivascular cells forming a stable population of macrophages in the brain. Thus, brain perivascular spaces are under permanent immune surveillance of blood borne macrophages in normal adult rats. (C) 2001 Academic Press.