脑型疟小鼠小胶质细胞的活化特征分析

Analysis of activation characteristics of microglia in cerebral malaria mice

目的利用血脑屏障分隔小胶质细胞与外周巨噬细胞,探讨小胶质细胞在实验型脑型疟(experimental cerebral malaria,ECM)发生中的活化特征。方法利用依文思兰渗出法确定ECM小鼠血脑屏障开放时间,在不同感染时间点,采用流式细胞技术和间接免疫荧光法检测小胶质细胞的活化特征,采用实时荧光定量PCR技术检测炎症和活化因子的变化。结果ECM小鼠血脑屏障显著开放始于感染后第6 d。感染后第5 d,脑内促炎因子、巨噬细胞活化相关因子的转录水平以及CD11b^(+)、CD45^(+)细胞的占比和数目均显著上调。CD11b^(+)细胞可根据CD45表达量分群,其中CD45^(high)亚群占比在感染后第5 d下调而第7 d上调。结论小胶质细胞参与ECM小鼠脑内炎症反应,且其活化与CD45表达量相关,CD11b^(+)CD45^(high)可作为活化小胶质细胞的标志物。

Objective To distinguish microglia from peripheral macrophages using the blood brain barrier(BBB),and to investigate the activation characteristics of microglia in the occurrence of experimental cerebral malaria(ECM).Methods The BBB opening time of ECM mice was determined by Evans blue exudation method.At different time points of infection,flow cytometry and indirect immunofluorescence method were used to detect the activation characteristics of microglia.Real time quantitative PCR was used to identify the changes of cytokines related to inflammation and activation.Results The BBB of ECM mice was significantly opened on the 6th day after infection.On the 5th day after infection,there were significant up-regulations on the transcription levels of proinflammatory factors and the macrophage activation-related factors and on the proportion and number of CD11b^(+)and CD45^(+)cells in the brain.The CD11b^(+)cells in the brain could be divided into groups according to the expression of CD45,and the proportion of CD45^(high) subgroup decreased on the 5th day after infection and increased on the 7th day after infection.Conclusions Microglia are involved in the inflammatory response in the brain of ECM mice,and their activation is related to the expression of CD45.The CD11b^(+)CD45^(high) can be used as a marker for the activation of microglia.