大鼠缺血脑组织中树突状细胞的来源与作用

The source and function of dendritic cells in rat ischemic brain tissue after middle cerebral artery occulation

目的 :探讨大鼠脑缺血后DC在脑损伤过程的意义。方法 :线栓法封闭大鼠右侧大脑中动脉。免疫组化检测缺血脑组织中DC的存在以及胶质细胞 巨噬细胞转化成DC的情况 ,并检测了DC样细胞的功能。结果 :比较缺血组两侧半球 ,缺血侧DC数量显著增多 (P <0 0 0 1)。比较缺血组与对照组 ,缺血组DC表达MHC II分子显著增高 (P <0 0 0 1) ,表达IL 10在 2 4h、48h也增高 (P <0 0 1,P <0 0 0 1)。比较缺血组两侧半球 ,6h和 12h缺血侧DC表达IL 1β明显增加 (P <0 0 5和P<0 0 1) ,12h、2 4h和 48hIL 6的表达显著升高 (P <0 0 5 ) ,TNF α的表达高峰分别为 6h～ 12h(P<0 0 5、P<0 0 1)和 48h～6d(P <0 0 1、P <0 0 5 )。结论 :脑缺血后DC参与了脑缺血病理过程 ,表达细胞因子产生免疫效应。

Objective:To explore the roles of dendritic cells(DC) in stroke process.Methods:The right middle cerebral arteries(MCAO) of rats were occluded by inserting nylon monofiament in the right external carotid artery.The quantity of DC,microglia/macrophage with and without DC5' surface mark on activated DC-like cells in ischemic brain hemispheres were detected by immunochemistry method.The function of DC-like cells had also analyzed.Results:The number of DCs in ischemic brain hemisphere was significantly higher than that of control after MCAO(P<0.001).Expression of MHC-II molecule were significantly higher on DCs in ishemic brain at the 6th day compared with control (P<0.001),and the expression of IL-10 were also higher after 24 and 48 hours of MCAO(P<0.01,P<0.001).Compared with both hemispheres of MCAO barins,expression of IL-1β in DCs of ischemic hemisphere were markedly increased at 6 h and 12 h(P<0.05 and P<0.01) than that of control,and IL-6 at 12 h,24 h,and 48 h were markedly increased (P<0.05).The peaks of TNF-α expressions were 6 h～12 h(P<0.05,P<0.01) and 48 h～6 d (P<0.05,P<0.05).Conclusion:DCs may play roles in cerebral ischemic proceses and participate in the injury process by producing cytokines after cerebral ischemia.