大鼠弥漫性轴索损伤后海马区caveolin-1的表达及其与星形胶质细胞活化的关系

Changes of caveolin-1 expression in the hippocampus of rats after diffuse axonal injury and its relationship with activation of astroglia

目的研究大鼠弥漫性轴索损伤(diffuse axonal injury,DAI)后小窝蛋白1(caveolin-1)在大鼠脑海马区的表达,探讨caveolin-1的表达变化与星形胶质细胞活化的关系。方法运用Western blot检测大鼠海马中caveolin-1的表达,运用免疫组化检测海马区胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达,并通过免疫荧光共定位分析caveolin-1与GFAP之间的相互作用。结果 Western blot结果提示DAI后海马区caveolin-1的表达从1d开始显著降低,并持续降低至7d(P<0.05);免疫组化结果提示DAI后星形胶质细胞活化标志物GFAP的表达从1d后逐渐升高,3d后达峰,7d后稍降低,但仍高于正常(P<0.05);免疫荧光共定位提示DAI后caveolin-1与GFAP的共定位细胞数随着时间的延长逐渐增加。结论大鼠DAI后海马区caveolin-1的表达减少,GFAP的表达增加,星形胶质细胞内caveolin-1的表达变化可能是导致GFAP升高及星形胶质细胞活化的机制之一。

Objective To explore the dynamic expression of cavcolin-1 in rat hippocampus after diffuse axonal injury （DAI） and its role in activation of astroglia. Methods Western blot was used to determine the expression of caveolin-1 in the hippocampus after DAI; immunohistochemistry staining was used to determine the dynamic expression of GFAP in the hippocampus of rats after DAI. The expression and co-localization of caveolin-1 and GFAP in rats after DAI were evaluated by immunofluorescence staining at different time points. Results The expression of caveolin-1 significantly decreased after DAI, and continued to decline from day 1 to day 7 （P^0.05）. Immunohistochemistry staining indicated that GFAP-positive cells significantly increased from day 1 to day 3, and slightly decreased at day 7 （P〈0.05）. The co-localization of caveolin-1 and GFAP revealed that the number of both caveolin-i- and GFAP-positive cells gradually increased. Conclusion Caveolin-1 expression significantly decreased with the increase of GFAP expression in the hippocampus of rats after DAI. Caveolin-1 may be involved in the dynamic expression of GFAP and play an important role in the activation of astroglia after DAI.