摘要
目的 研究局部脑缺血模型小胶质细胞的激活和白细胞的浸润情况 ,以进一步研究脑卒中后引起炎症反应的细胞及分子机制。方法 用免疫组化方法研究单克隆抗体CD11b ,Ly 6G ,CD3和CD4 5 /B2 2 0在大脑中动脉闭塞 (MCAO) 6 0min进行不同时段灌注后在脑组织中的表达。结果 灌注早期 (18～ 2 4h)在脑梗塞区就可见被激活的CD11b阳性的小胶质细胞 ,在 18～ 2 4h灌注期 ,可见CD11b阳性的巨噬细胞和Ly 6G阳性的中性白细胞黏附在脑膜的血管壁。灌流 4 8～ 72h ,CD11b阳性的巨噬细胞和Ly 6G阳性的中性白细胞从血管壁迁移到脑梗塞区。在灌流 2 4～ 4 8h ,我们仅见到个别CD3阳性T淋巴细胞和CD4 5 /B2 2 0阳性B淋巴细胞。然而 ,在灌流 72h后 ,可容易地检测到CD3阳性T淋巴细胞。 结论 研究结果表明单核吞噬细胞系统在MCAO脑卒中模型的炎症反应中起重要作用。在灌注早期CD11b阳性细胞主要为脑实质内被激活的小胶质细胞 ,灌注 2 4～ 72h ,外周血循环中的巨噬细胞和其他白细胞从血管迁移到缺血区以及被激活的小胶质细胞一同在脑卒中炎症反应中起作用。
Objective To identify microglial activation and leukocyte infiltration in focal cerebral ischemia for further research on the cellular and molecular mechanisms that lead to inflammation following stroke. Methods Immunocytochemistry (IHC) was used to investigate the expression of CD11b, Ly-6G, CD3 and CD45/B220 in cerebral ischemia induced by 60 min temporary occlusion of the middle cerebral artery followed by reperfusion for varying times. Results At early time points (18-24 h), resident CD11b + microglia appeared activated at the site of infarct. Peripheral CD11b + macrophages and Ly-6G + neutrophils were observed adhering to meningial vascular walls at 18-24 h of reperfusion. CD11b + macrophages and Ly-6G + neutrophils migrated from vessel walls into the parenchyma of the infarct following 48-72 h reperfusion. Minimal numbers of CD3 + T lymphocytes and CD45/B220 + B lymphocytes were detected at 24-48 h reperfusion. However, following 72 h reperfusion, CD3 + T lymphocytes were readily detected. Conclusion The data indicate that the mononuclear phagocytic system plays an important role in the inflammatory response following ischemic injury. The early inflammatory response cell appears to be primarily activated microglia, and around 24-72 h peripheral macrophages with other leukocytes from the circulation migrate into the ischemic site contributing to inflammatory response in stroke.
基金
NationalInstitutesofHealthgrant (5R0 1 NS3 9492 0 2 ),USA
