β-DG对脑内水通道蛋白4极性表达变化的影响

Effect of β-dystroglycan on the polarized expression of aquaporin 4 in brain

目的:观察脑出血(intracerebral hemorrhage,ICH)后大鼠脑组织中β-肌营养不良聚糖(β-dystroglycan,β-DG)的表达变化,以探讨其对水通道蛋白4(aquaporin 4,AQP4)极性表达变化的的影响。方法:健康雄性SD大鼠68只,随机分为假手术对照组(sham组)、ICH后1、3 d和7 d共4组,采用自体血注入法建立大鼠ICH动物模型,HE染色和透射电镜检测组织结构病理变化,免疫印迹检测血肿周围组织中β-DG蛋白的表达变化,免疫荧光双标记检测AQP4与β-DG的共表达变化。每个时间点用于透射电镜检测、免疫印迹和组织切片的大鼠数量分别为5、6只和6只。结果:ICH后1 d血肿周围组织结构破坏最为明显,可见毛细血管内皮细胞肿胀及血管周围间隙增宽等改变。ICH后1、3、7 d的血肿周围组织中,β-DG蛋白含量分别为(0.251±0.038)、(0.396±0.069)、(0.398±0.086),与sham组(0.610±0.121)比较,均明显降低,且差值均具有统计学意义(P=0.000)。与sham组中AQP4与β-DG严格的共表达不同,ICH后脑组织中,伴随着AQP4极性表达缺失,β-DG的表达明显降低。结论:β-DG表达下调可能促进了ICH后脑组织中AQP4的极性表达缺失。

Objective：To observe the changes of β-dystroglycan（β-DG）expression in the brain post intracerebral hemorrhage（ICH）,and to explore its effect on the polarized expression of aquaporin4（AQP4）. Methods：Sixty-eight male SD rats were randomly divided into sham group and ICH group（including ICH post day 1,day 3,and day 7 groups）. Autologous blood was injected into the right caudate nucleus to establish ICH model in rats. HE staining and transmission electron microscope（TEM）were used to observe the structure changes;Western blot was used to detect the changes of β-DG protein in the perihematomal tissue and the co-expression of AQP4 and β-DG were detected by immunofluorescence. Results：In the perihematomal tissue, the organization structure was destroyed obviously,especially in the tissue of ICH post day 1 group;the endothelial cell of capillary was swollen and perivasicular gap was widened. In the perihematomal tissue,the β-DG protein of ICH post day 1,day 3,day 7 groups was（0.251±0.038）,（0.396±0.069）,（0.398±0.086）respectively,signifantly different from that of（0.610 ± 0.121）in sham group（P=0.000）. Different from the co-expression of AQP4 and β-DG in the sham group,the expression of β-DG was significantly decreased in the brain tissue post ICH,while the polarized expression of AQP4 was lost. Conclusion：The decreased expression of β-DG may contribute to the loss of AQP4 polarized expression in the brain tissue post ICH.