Wnt通路信号蛋白β-链蛋白、糖原合成酶激酶-3β在小鼠脑缺血再灌注损伤后的表达变化

The Expression Rule of Correlation Factors of Wnt Signal Pathway in Mice Cerebral Ischemia-Reperfusion Injury

目的：初步探讨Wnt信号通路中相关因子在小鼠脑缺血再灌注损伤中的表达规律。方法将96只1月龄健康昆明雄性小鼠随机分为正常组、假手术组和缺血再灌注后1 d、7 d、14 d、28 d组，采用夹闭小鼠双侧颈总动脉制作脑缺血再灌注损伤模型。通过Y-迷宫检测小鼠学习记忆能力，TTC染色和透射电镜观察小鼠海马形态结构，免疫组织化学染色方法检测β-链蛋白（β-catenin）、糖原合成酶激酶-3β（GSK-3β）的表达变化。结果小鼠脑缺血再灌注后身体出现神经功能损伤症状，同时学习记忆能力明显下降。脑片TTC染色海马区出现白色梗死灶，透射电镜显示海马区神经元细胞水肿，线粒体肿胀，核固缩，核膜间隙扩大。免疫组化显示正常组和假手术组中β-catenin呈弱阳性，GSK-3β呈阳性。脑缺血再灌注损伤后，GSK-3β阳性细胞呈低表达，21 d升高；而β-catenin在缺血再灌注后脑组织中均有表达，且阳性表达于7 d达到高峰，随后开始下降，28 d降至正常，两者呈显著负相关（P＜0.05）。结论初步证实夹闭小鼠双侧颈总动脉成功构建脑缺血再灌注损伤模型，同时Wnt信号通路参与脑缺血再灌注损伤的发生。

Objective To discuss the expression rule of correlation factors of Wnt signal pathway in mice cerebral ischemia-reperfusion injury.Methods 96 one-month healthy Kunming male mice were randomly divided into the normal group, the sham operation group and 1 d, 7 d, 14 d, 28 d after cerebral ischemia-reperfusion groups. The common carotid arteries of mice were clipped to make the cerebral ischemia-reperfusion injury model. Y-maze was used to test the learning and memory ability of mice. TTC dyeing and transmission electron microscope were used to observe the morphological structure of hippocampus. Immunohistochemistry staining method was used to test the expression change ofβ-catenin and GSK-3β.Results After cerebral ischemia-reperfusion, nerve function impairment occurred to the body of mice and the learning and memory ability decreased evidently. White infarct lesions appeared in the brain slice TTC dyeing hippocampus. Transmission electron microscope showed that there are neuron edema in the hippocampus and mitochondrial swelling, karyopyknosis and expanding nuclear membrane clearance. The immunohistochemistry showed thatβ-catenin presented in weak positive, GSK-3β presented in positive in the normal group and the sham operation group. After cerebral ischemia-reperfusion, GSK-3β positive cells presented low expression, and increased at 21 d; whileβ-catenin was expressed in the brain tissue after cerebral ischemia-reperfusion and the positive expression reached the peak at 7 d, then decreased, and back to normal at 28 d. These two indexes were negatively related （P〈0.05）.Conclusion It primarily confi rmed that clipping the bilateral carotid arteries can successfully construct cerebral ischemia-reperfusion injury model. At the same time, Wnt signal pathway involves the occurrence of cerebral ischemia-reperfusion.