Enhanced expression of Iba1, ionized calcium-binding adapter molecule 1, after transient focal cerebral ischemia in rat brain
Enhanced expression of Iba1, ionized calcium-binding adapter molecule 1, after transient focal cerebral ischemia in rat brain
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DOI：
10.1161/01.str.32.5.1208
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发表时间：
2001-05-01
期刊：
影响因子：
8.3
通讯作者：
Fukuuchi, Y
中科院分区：
文献类型：
--
作者：
Ito, D;Tanaka, K;Fukuuchi, Y
背景和目的-Iba 1是一种新的钙结合蛋白，在脑内小胶质细胞中特异性表达。Iba 1在小胶质细胞功能调控中起重要作用。Tn本研究中，我们研究了时间依赖性的Iba 1表达短暂的大脑中动脉闭塞后，其特点是小胶质细胞活化在不同的大脑regions. Methods大鼠大脑中动脉闭塞引起的管腔内细丝技术，短暂缺血1.5小时后，Iba 1表达进行了检查，免疫组化和免疫印迹分析。小胶质细胞活化与缺血严重程度标志物相关。的特点是双重免疫染色与其他特定markers.Results-in缺血周围区，重Iba 1免疫反应阳性细胞迅速出现在再灌注后3.5小时。免疫反应性进一步增加，并在第7天达到峰值。在缺血中心，圆形Iba 1阳性细胞，这可能是血液传播的单核细胞，从24小时开始出现，并在4 - 7天达到高峰。双重免疫染色显示，在周围缺血区激活的小胶质细胞上调Iba 1的表达，但阴性的巨噬细胞标志物ED 1。ED 1阳性细胞明显局限于缺血核心区。结论：（1）Iba 1表达可能与缺血脑内小胶质细胞活化有关，Iba 1免疫染色可用于评估活化小胶质细胞在缺血损伤中的病理生理作用。(2)ED 1抗原的表达仅限于严重缺血性脑损伤，而在缺血周围区激活的小胶质细胞在无ED 1的情况下显示Iba 1上调，因此，小胶质细胞在缺血性脑损伤的严重程度上可能表现出不同的抗原性。
Background and Purpose-Iba1 is a novel calcium-binding protein and is specifically expressed in microglia in the brain. It has been suggested that Iba1 plays an important role in regulation of the function of microglia. Tn the present study we examined time-dependent Iba1 expression after transient middle cerebral artery occlusion and characterized microglial activation in various brain regions.Methods-Rat middle cerebral artery occlusion was induced by the intraluminal filament technique, After 1.5 hours of transient ischemia, Iba1 expression was examined by immunohistochemical and immunoblot analyses. The microglial activation in association with ischemic severity markers. was characterized by double immunostaining with other specific markers.Results-In the peri-ischemic area, heavily Iba1 immunoreactive cells rapidly appeared at 3.5 hours after reperfusion. Immunoreactivity was further increased and peaked at 7 days. In the ischemic core, round Iba1-positive cells, which may be blood-borne monocytes, appeared from 24 hours and reached a peak at 4 to 7 days. Double immunostaining revealed that activated microglia in the peri-ischemic area upregulated Iba1 expression but were negative for the macrophage marker ED1. ED1-positive cells were clearly restricted to the ischemic core.Conclusions-These findings suggest the following: (1) Iba1 expression may be associated with microglial activation in ischemic brain, and Iba1 immunostaining can be useful to evaluate the pathophysiological roles of activated microglia in ischemic injury. (2) Expression of ED1 antigen is strictly restricted to severe ischemic damage, whereas activated microglia in the peri-ischemic area showed Iba1 upregulation without ED1, Therefore, microglia may exhibit difference of antigenicity in the severity of ischemic brain injury.