小鼠脑缺血后小胶质细胞活化及细胞周期蛋白的表达规律

Microglia activation and cell cycle protein expression after cerebral ischemia in mouse

目的：探讨小鼠脑缺血后小胶质细胞活化及细胞周期蛋白D1与细胞周期蛋白依赖蛋白激酶4（CDK4）的表达规律。方法：采用线栓法制作小鼠脑缺血／再灌注（I／R）模型，动物随机分为假手术组和缺血组，缺血组在缺血40min再分为再灌注3h、5h、12h、1d、3d和5d组，组织化学显色观察小胶质细胞活化规律，免疫组织化学显色观察细胞周期蛋白D1和CDK4的表达。结果：缺血再灌注12h后活化的小胶质细胞增多，缺血再灌注3d后活化的小胶质细胞显著增多，5d后活化的小胶质细胞持续增加。细胞周期蛋白DI表达缺血再灌注1d达高峰，3d和5d时细胞周期蛋白D1表达下降。CDK4表达在缺血再灌注3d达高峰，5d后开始下降。结论：细胞周期蛋白D1和CDK4与小胶质细胞的活化不同步，细胞周期蛋白D1和CDK4可促进小胶质细胞的活化。

Objective： To explore the pattern of microglia activation and expression of cyclin D1 and cyclin-dependent kinase 4 （CDK4） after cerebral ischemia in mice. Methods：The focal cerebral ischemia/reperfusion（l/R） model in mouse was made by using middle cerebral artery occlusion. Mice were randomly divided into the following groups： sham group, occluded for 40 min and reperfusion for 3 h, 5 h, 12 h, 1 d, 3 d and 5 d. The histochemical staining was used to observe the activation of microg/ia by IB4 after isehemia. The immunohistochemical staining was used to study the distribution of cyelin D1 and CDK4. Results：Activating microglia increased after ischemia reperfusion 12 h. Activating mieroglia significantly increased 3 d after ischemia reperfusion, and microglia cells continues increased 5 d after ischemia reperfusion. Cyclin D1 expression was peaked at 1 d after reperfusion, and cyclin D1 expression decreased from 3 d. CDK4 immunoreactivity increased to the peak after ischemia reperfusion 3 d, and CDK4 expression decreased from 5 d. Conclusion：Microglia activation and expression of cyclin D1 and CDK4 is not synchronized, while eyclin D1 and CDK4 can promote microglia activation.