微管相关蛋白-1B在弥漫性轴索损伤中的表达变化与意义

Expression and significance of microtubule-associate protein 1B in rats with diffuse axonal injuries

目的 :观察微管相关蛋白-1B(microtubule-associate protein 1B,MAP1B)在SD大鼠弥漫性轴索损伤(diffuse axonal injury,DAI)后脑组织中表达的变化,探索其表达变化的意义。方法 :采用改良的Marmarou法建立SD大鼠DAI模型,分为空白对照组(10只,不予任何处理),假打击组(10只,给予致伤组相同的打击前准备,但不予以打击),致伤6 h组(10只),致伤1 d组(10只)和致伤3 d组(10只),分别于打击6 h、1 d、3 d后,处死动物,提取脑组织,结合Western blot和免疫组化方法,观察SD大鼠脑组织中MAP1B表达的变化。结果:Western blot结果显示致伤6 h组(0.50±0.07)、致伤1 d组(0.56±0.07)和致伤3 d组(0.50±0.06)中MAP1B表达水平较空白对照组(0.30±0.06;P=0.001,P=0.000,P=0.001)、假打击组(0.30±0.04;P=0.001,P=0.000,P=0.001)明显升高。免疫组化结果显示致伤6 h组(4.70±0.79)、致伤1 d组(4.78±0.86)和致伤3 d组(4.70±0.89)中MAP1B表达水平较空白对照组(4.06±1.15;P=0.023,P=0.007,P=0.023)、假打击组(3.90±1.46;P=0.002,P=0.000,P=0.002)明显升高。结论:SD大鼠DAI后脑组织中MAP1B表达水平上调,提示其参与了DAI后轴索损伤的病理改变过程,并可能在稳定、修复及再生受损轴索的机制中起着重要作用。

Objective：To examine the expression of the microtubule-associate protein 1B（MAP1B）in rats with diffuse axonal injury（DAI）as well as to elucidate the mechanisms of MAP1 B in the procession of axonal repairment. Methods：DAI was induced in adult male SD rats using an injury model adapted from Marmarou. The rats were divided into five groups： injured 6 h group（n=10）,injured1 d group（n=10）,injured 3 d group（n=10）,sham group（n=10）and sham-injured group（n=10）. The animals were sacrificed at 6 h,on 1 d and 3 d post injury. Western blot and immunohistochemistry were performed to observe the expression of MAP1 B in rats with DAI. Results ：Western blot and immunohistochemistry analyses showed MAP1 B expression was up-regulated in the brain tissues of injured 6 h group,injured 1 d group,injured 3 d group than in sham group and sham-injured group. Conclusion：Expression of MAP1 B is increased in the brain tissues of injury group,indicating that MAP1 B may be involved in the pathophysiological mechanisms of DAI and may play an important role in the repair of the axon after head trauma.