慢性脑缺血对小鼠脑内星形胶质细胞的影响

Effects of chronic cerebral hypoperfusion on astrocytes in mice

摘要:

目的：研究慢性脑缺血对小鼠脑内星形胶质细胞的影响。方法：C57小鼠，3月龄时行改良双侧颈总动脉结扎术，假手术组对照。甲苯胺蓝染色观察模型有效性。于术后1、2、4、5、6个月胶质原纤维酸性蛋白（glial fibrillary acidic protein，GFAP）免疫组化观察小鼠脑内星形胶质细胞的病理改变。免疫印迹检测脑内GFAP表达量变化。结果：甲苯胺蓝灌注后，模型0 h组大脑冠状切面苍白色，假手术对照组呈深蓝色。慢性脑缺血后，星形胶质细胞增生，表现为细胞数量增多，胞体肿胀肥大，突起增多，变粗，变长。与假手术对照组比较，从模型2个月组开始，GFAP阳性细胞数量持续性增多，染色加深，累计光密度增强，且差异均具有统计学意义（P<0.05）。免疫印迹结果显示，与假手术对照组比较，模型2、4、5、6个月组脑内GFAP表达量增高，差异有统计学意义（P<0.05）。结论：慢性脑缺血后星形胶质细胞出现持续性增生，可能在缺血性脑损伤后脑内的不可逆病理改变中有重要意义。

Abstract:

Objective：To investigate the effect of chronic cerebral hypoperfusion on astrocytes in mice brain. Methods：Three months old C57 mice were subjected to chronic cerebral hypoperfusion with 2 vessels occlusion or sham operation. Anilin blue staining was used to prove the effectiveness of the model. Pathological changes of astrocytes were examined by immunohistochemicalstaining（IHC） of glial fibrillary acidic protein（GFAP）. Western blot was employed to test the levels of GFAP in brain. Results：After the Anilin blue perfusion，cerebrum of model 0 h group was not dyed while that of sham control group was dyed dark blue. After chronic cerebral hypoperfusion，astrocytes were proliferated and manifested as cell quantity increase，cellular hypertrophy and processes. Two months after model establishment，number of GFAP positive cells was increased，dying was deepened and integrated optical density was enhanced compared with those in sham control group，with statistical differences（P<0.05）. Intracerebral GFAP expression in model group was increased significantly compared with that in sham control group，with statistical differences（P<0.05）. Conclusions：Astro－cytes are consistently proliferated after chronic cerebral hypoperfusion，which play an important role in irreversible pathological changes after cerebral ischemia.