大鼠脑外伤后星形胶质细胞及血清中相关蛋白随时间表达变化研究

Time-dependent expression changes of astrocytes and related proteins in serum after diffuse brain injury in rats

目的:检测大鼠弥漫性脑损伤(DBI)后不同时间点A1型星形胶质细胞(A1s,其标记物为C3d)、A2型星形胶质细胞(A2s,其标记物为S100A10)的表达情况,以期探索其与损伤时间的关系。方法:采用改良的Marmarou方法制造大鼠DBI模型,将48只SD大鼠随机分为正常对照组(Control组),DBI后4、8、12 h,1、3、5、7 d组,采用免疫荧光染色实验检测大鼠DBI后海马组织中A1s、A2s表达变化,采用酶联免疫吸附(ELISA)实验检测大鼠DBI后血清中神经胶质纤维酸性蛋白(GFAP)、C3d、S100A10蛋白的表达变化。结果:免疫荧光染色结果显示,Control组大鼠海马组织仅见少量A1s分布,DBI 4 h后表达呈上升趋势,DBI 1 d后达高峰,随后逐渐减少;正常大鼠星形胶质细胞主要以A2s形式存在,DBI后4 h其表达减少,至1 d时最低,随后表达逐渐升高(均P<0.05)。ELISA检测结果显示:与Control组相比,GFAP、C3d在DBI 4 h后表达呈上升趋势,DBI 1 d左右两者表达呈现高峰,后逐渐下降;而S100A10在DBI 4 h后也呈上升趋势,3 d左右达高峰,后逐渐下降,DBI后7 d仍高于Control组(均P<0.05)。结论:大鼠DBI后,海马组织中A1s、A2s及血清中GFAP、C3d、S100A10的表达呈现一定规律性,有望为弥漫性脑损伤的时间推断及临床治疗提供一定的依据。

Objective:To detect the expression of A1 astrocytes(A1s,marked by C3d)and A2 astrocytes(A2s,marked by S100A10)at different time after diffuse brain injury(DBI)in rats,in order to explore the relationship between A1s/A2s and injury time.Methods:The DBI model of rats was made by modified marmarou.A total of 48 SD rats were randomly divided into normal control group(control group)and 4-hour,8-hour,12-hour,1-day,3-day,5-day and 7-day groups after DBI.Immunofluorescence staining was used to detect the expression of A1s,A2s in hippocampus after DBI.The double-antibody sandwich enzyme-linked immunosorbent assay(ELISA)was used to detect the expression of GFAP,C3d and S100A10 proteins in serum after DBI.Results:Immunofluorescence staining showed that there was only a few of A1s in the hippocampus of control group,which increased after 4 hours of DBI,reached the peak after 1 day of DBI,and then decreased gradually,while the astrocytes of normal rats mainly existed in the form of A2s,decreased after 4 hours of DBI,decreased to the lowest after 1 day of DBI,and then increased gradually(all P<0.05).The results of ELISA detection showed that compared with control group,the expression of GFAP and C3d increased after 4 hours of DBI,peaked around 1 day after DBI,and then decreased gradually,while S100A10 also increased after 4 hours of DBI,reached the peak at about 3 days after DBI,then decreased gradually,and was still higher than that in control group 7 days after DBI.Conclusion:After DBI,the expressions of A1s,A2s in hippocampus and GFAP,C3d,S100A10 in serum show certain regularity,which is expected to provide a basis for the estimation of the time and clinic treatment of diffuse brain injury.