缺氧缺血脑损伤大鼠脑组织Cofilin 1与ERK1/2蛋白表达与磷酸化的分析

目的探索新生大鼠缺氧缺血脑损伤模型脑组织Cofilin1与ERK1/2蛋白表达与磷酸化及其在脑组织中分布的规律。方法新生7日龄SD大鼠,手术结扎左侧颈总动脉并经低氧处理造成缺氧缺血脑损伤(HIBD)模型,以假手术组为对照,应用western Blot和免疫组化方法检测损伤后一定时间段(0h～48h)损伤侧脑组织Cofilin1与磷酸化cofilin1(p-Cofilin1)及Erk1/2和磷酸化ERK1/2(p-ERK1/2)的表达变化,同时检测其在损伤大鼠脑组织和细胞中的表达和分布。结果 Western blot检测显示,HIBD新生SD大鼠脑组织中Cofilin1在HI后的表达与对照组相比也未见明显改变,但磷酸化Cofilin1在HI后1h～12h之间降低,24h后恢复正常;ERK1/2蛋白在不同时点的表达与对照组相比未见明显差异,但可见磷酸化ERK1/2(p-ERK1/2)在缺氧缺血处理(HI)后0h略低于正常,而在1-2h内迅速升高并高于正常对照和假手术,在2h后又逐渐降低。免疫组化结果显示Cofilin1与p-cofilin1在损伤大鼠脑中主要分布于海马和大脑皮质,尤其p-Cofilin表达分布以海马的颗粒细胞为主,并且在HI后7d-14d表达明显增强,在21d则明显降低。结论 Cofilin和ERK的磷酸化修饰与缺氧缺血脑损伤的发生和发展过程有较密切的关系,且cofilin1和p-cofilin1在大脑海马区的定位分布,提示其可能与大脑的学习记忆功能的损伤与修复有一定的关系。

Analysis of Cofilin 1 and ERK1/2 protein expression and phosphorylation in hypoxia and ischemia brain damage of rats

Objective To explore the changes of Cofilin-1 and ERK1/2 protein expression and phosphorylation in newborn rats with hypoxia-ischemia brain damage(HIBD),and the distribution in hippocampus and cortex.Methods The left arteria carotis communis in newborn SD rats of age 7th days was ligated for 2 hours and the rats were treated by low oxygen processing to set up HIBD model.Western blot and immunohistochemistry were applied to examine cofilin 1,p-Cofilin 1,ERK1/2 and p-ERK1/2 expressions and their distribution in damaged rat brain.Results Western blot revealed that there was no obvious change for the expression of Cofilin1 and ERK1/2 between damaged and control groups,but the expression level of p-Cofilin1 reduced 1h ~ 12h after HI,and turned to normal 24h after HI,the expression level of p-ERK1/2 was slightly lower 0 h after HI,increased 1-2h after HI,and then gradually reduced 2h after HI compared to sham group.Immunohistochemistry showed that Cofilin 1 and p-Cofilin 1 positive cells mainly distributed in hippocampus and cortex,and their expression level enhanced 7 d~14 d after HI,decreased 21 d after HI.Conclusion p-Cofilin1 and p-ERK1/2 might be involved in the process of hypoxia-ischemia brain damage,the localizaton of cofilin1 and p-cofilin1 in the cerebral cortex and hippocampus might be related to memory function.