Distinct physiologic properties of microglia and blood-borne cells in rat brain slices after permanent middle cerebral artery occlusion
Distinct physiologic properties of microglia and blood-borne cells in rat brain slices after permanent middle cerebral artery occlusion
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DOI：
10.1097/00004647-200011000-00003
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发表时间：
2000-11-01
影响因子：
6.3
通讯作者：
Dirnagl, U
中科院分区：
文献类型：
--
作者：
Lyons, SA;Pastor, A;Dirnagl, U
作者观察了成年大鼠大脑中动脉永久性闭塞(MCAO)后脑片中白细胞浸润和小胶质细胞活化的时程变化。为了区分外周血白细胞和小胶质细胞，在诱导缺血前用罗丹明6G(Rhod6G)IV在体内预先标记血细胞。在梗死后的特定时间，用异凝素(IL)B4-FITC(ILB4)原位标记侵袭的白细胞、小胶质细胞和内皮细胞。MCAO后6h，仅有少数ILB4+细胞被Rhod6G标记。这些细胞表达巨噬细胞特有的电压门控内外整流钾电流。大多数ILB4+细胞是Rhod6G-，表达缺乏电压门控通道，最近被描述为脑片中分支的小胶质细胞，或者只表现出内向整流电流，这是培养(但未刺激)小胶质细胞的独特标志。MCAO后48小时，所有血源性和大部分Rhod6G-细胞均表达外向和内向电流，表明固有的小胶质细胞群具有刺激培养的小胶质细胞的生理特征。ILB4+/Rhod6G内源性小胶质细胞群在梗死灶边缘更为丰富，形态由放射状变为阿米巴状。在这个区域内，作者观察到了快速迁移的细胞，并用时间推移显微镜记录了这种移动。目前的研究结果表明，小胶质细胞在MCAO后较晚的时间点获得了白细胞的生理特征。
The authors investigated the time course of leukocyte infiltration compared with microglial activation in adult rat brain slices after permanent middle cerebral artery occlusion (MCAO). To distinguish peripheral leukocytes from microglia, the blood cells were prelabeled in vivo with Rhodamine 6G (Rhod6G) IV before induction of ischemia. At specific times after infarct, invading leukocytes, microglia, and endothelial cells were labeled in situ with isolectin (IL)B4-FITC (ILB4). Six hours after MCAO only a few of the ILB4+ cells were colabeled by Rhod6G. These cells expressed the voltage-gated inwardly and outwardly rectifying K+ currents characteristic of macrophages. The majority of the ILB4+ cells were Rhod6G- and expressed a lack of voltage-gated channels, recently described for ramified microglial cells in brain slices, or exhibited only an inward rectifier current, a unique marker for cultured (but unstimulated) microglia. Forty-eight hours after MCAO, all blood-borne and the majority of Rhod6G- cells expressed outward and inward currents indicating that the intrinsic microglial population exhibited physiologic features of stimulated, cultured microglia. The ILB4+/Rhod6G- intrinsic microglial population was more abundant in the border zone of the infarct and their morphology changed from radial to ameboid. Within this zone, the authors observed rapidly migrating cells and recorded this movement by time-lapse microscopy. The current findings indicate that microglial cells acquire physiologic features of leukocytes at a later time point after MCAO.