LPS诱导小鼠脑小胶质细胞的激活及Tomato lectin的表达变化

探讨小胶质细胞对侧脑室注射内毒素脂多糖(lipopolysaccharide,LPS)刺激的反应及时程变化。采用组织化学方法,观察小鼠单次注射LPS入侧脑室后,Tomatolectin阳性的小胶质细胞于不同时间点在脑内的分布及表达的时程变化。LPS注射24h后,Tomatolectin组织化学染色显示血管内皮细胞、静息的和不同激活状态的小胶质细胞均呈阳性反应,其中Tomatolectin阳性的小胶质细胞明显被激活,2d时达表达高峰,巨噬细胞样的细胞和小胶质细胞呈现出肥大的、阿米巴样或杆状细胞等不同激活状态下的形态特征。这些激活的小胶质细胞主要分布于侧脑室周围的脑实质结构,如海马、隔区、胼胝体、纹状体,第三脑室周围的下丘脑及其它间脑结构。本结果提示:LPS能诱导小鼠脑室周围的脑实质内的小胶质细胞被激活,并上调小胶质细胞内Toma-tolectin的表达,这些细胞可能参与脑内刺激的免疫调节。

LIPOPOLYSACCHARIDE INDUCED MICROGLIA ACTIVATION AND CHANGE OF EXPRESSION OF TOMATO LECTIN IN MICROGLIA OF MOUSE BRAIN

To investigate the activation of microglia of mice brain and temporal change after a single intracerebroventricular (ICV) stereotaxically injection of lipopolysaccharide (LPS). The histochemical method was used to observe the distribution of Tomato lectin-positive microglia in brain and temporal change of expression of Tomato lectin at different time-points after LPS injection into the right lateral cerebral ventricle of mice. At 24 h after LPS injection, histochemical staining for Tomato lectin showed the blood vessel endothelia, as well as of resting microglia and of microglial cells in various states of activation were positive reaction. Macrophage-like cells and microglia exhibiting the features of hypertrophic, amoeboid or rod-shaped cells were most evident in the cases sampled 2 days after LPS injection. Numerous activated microglia were observed mainly in periventricular areas, such as the hippocampus, septum, corpus callosum, the striatal parenchyma bordering the lateral ventricle, in the hypothalamic structures close to third ventricle, as well as in other diencephalic structures. The results suggest that LPS could induce marked activation of microglial cells and up-regulation of Tomato lectin expression in microglia in the mouse brain in periventricular area, which may participate in central-immunity regulation in brain stimulated.