大鼠短暂脑缺血后海马区c-fos mRNA和FOS蛋白表达的时间规律

The time pattern of c-fos mRNA and FOS protein expression in the hippocampus region in rat models of cerebral ischemia-reperfusion

目的 探讨大鼠脑缺血 再灌注后脑海马区c fosmRNA和FOS蛋白表达规律。方法 采用左侧大脑中动脉插入丝线结扎 (LMCAO)方法制作大鼠脑缺血 再灌注缺血模型 ,分别按照 30min至 7d的不同灌注时间取材 ,应用原位杂交方法标记各实验组大鼠脑组织海马区c fosmRNA表达数量 ;应用免疫组化方法标记各实验组大鼠脑组织中海马区FOS阳性神经元数量。结果 c fosmRNA阳性细胞在MCAO缺血再灌注 1h后开始表达 ,2h后达高峰 ,至 2d时c fosmRNA阳性细胞表达基本消失 ;c fos免疫活性细胞从 2h开始表达 ,4h达高峰 ,4d时表达基本消失。脑缺血 再灌注后c fosmRNA与FOS蛋白在海马区表达具有一定的时间上规律性。结论 本研究证明了大鼠MCAO缺血 再灌注后可诱发FOS蛋白和c fosmRNA表达增加 ,且基因和蛋白的表达均具有一定的时间规律性和相关性。

Objective To approach on the time relationship of expression of c-fos mRNA and FOS protein in the hippocampus regions of MCAO rat models of cerebral ischemia-reperfusion.Methods Cerebral ischemic rat models wers subjected to left middle cerebral artery occlusion (LMCAO) by a suture.According to the literatures the rats were sacrificed at time points from 30 minutes to 7 days after reperfusion.Sham-operated rats were regarded as a control group.We measured the number of the expression of c-fos mRNA an FOS protein in the hippocampal region in brain tissue from ischemic rats using in situ hybridization and immunohistochemistry.Results The c-fos mRNA expression increased significantly in the ischemic region as early as 1 h after reperfusion.The c-fos mRNA continued to increase and peaked at 2 h after reperfusion, even until the 2nd day after that, the expression of c-fos mRNA was found at very low levels in all regions examined; For the protein of c-fos, its expression started from 2 h, and reached a peak at 4 h , up to 4 th day.After 4 days its expression did not appear any more.FOS expression was strongest at 4 h, but became undetectable after 4 d in the hippocampus.Conclusions The time of the beginning and the peak of the expression of c-fos mRNA and FOS protein showed some regularity at time.