脑出血后血脑屏障紧密连接蛋白occludin的表达变化  

Changes of tight junction protein occludin expression in blood-brain barrier of rats after intracerebral hemorrhage

作　　者：李兵[1] 陈祎招[1] 蒋伟平[1] 邓心情[1] 杨硕[1] 徐如祥[2] 

机构地区：[1]南方医科大学珠江医院神经外科,广东省神经外科研究所,广东省脑功能修复与再生重点实验室,广州510282 [2]北京军区总医院八一脑科医院,北京100700

出　　处：《中华神经医学杂志》2012年第6期575-580,共6页Chinese Journal of Neuromedicine

基　　金：国家自然科学基金（30500526）;广东省自然科学基金（53000468）;国家临床重点专科建设项目

摘　　要：目的探讨脑出血后血脑屏障微血管内皮细胞间紧密连接蛋白occludin的表达变化。方法将SD雄性大鼠按随机数字表法分为正常对照组和脑出血组．再按时间因素将脑出血组分为出血后6h、24h、48h、72h、7d、14d6个亚组。采用脑内注入自体血法制作脑出血模型。HE染色观察脑出血后血肿周围脑组织的形态学改变：透射电镜观察脑出血后血肿周围紧密连接的超微结构改变；免疫荧光染色检测脑出血后血肿周围紧密连接蛋白occludin的表达分布状况：定量RT—PCR检测脑出血后血肿周围脑组织中occludinmRNA的表达状况。结果与正常对照组相比，脑出血组血肿周围脑组织出现水肿，在48h左右尤为明显，局部可见明显脑细胞坏死及炎细胞浸润。脑出血后血肿周围紧密连接发生明显破坏，内皮细胞间出现裂隙。免疫荧光染色结果显示：正常对照组紧密连接蛋白occludin呈强阳性表达。脑出血后6hoccludin的表达即开始下降，呈阳性表达；脑出血后24～72hoccludin的表达维持在较低水平，呈弱阳性表达。定量RT-PCR结果显示：脑出血后血肿周围脑组织中occludinmRNA相对含量明显降低，在6—72h持续维持在较低水平，与正常对照组比较差异均有统计学意义（P〈0．05）。结论脑出血发生后，紧密连接蛋白occludin的表达下降，这可能是脑出血发生后血脑屏障破坏及脑水肿发生发展的重要分子基础之一。Objective To investigate the changes of fight junction （TJ） protein occludin expression between the microvascular endothelial cells of the blood-brain barrier （BBB） of rats after intracerebral hemorrhage （ICH）. Methods Ninety-three male SD rats were randomly divided into normal control group and experimental group; rats of the experimental group were divided into 6 subgroups （6, 24, 48 and 72 h, and 7 and 14 d after intracerebral hemorrhage）. Rat models of intracerebral hemorrhage in the experimental group were established by autologous blood injection. Morphology of the brain tissues was detected by hematoxylin-eosin （HE） staining. The tight junctions between the microvascular endothelial cells of the BBB were sampled for ultrastructural observation using electron microcopy. Immunofluorescence and quantitative real time-PCR were used to analyze the protein and mRNA expressions of occludin, respectively. Results The brain edema was found in brain tissues around the hematoma. Necrosis and inflammatory infiltration could be found in perihematomal brain tissues and it was most obvious at 48 h after intracerebral hemorrhage. Obvious paracellular clefts were found between the adjacent endothelial cells in experimental groups. Strong expression of occludin was noted in the normal brain tissue; expression of occludin was positive 6 h after the injection and weak positive at 24, 48 and 72 h after the injection in the experimental groups. Quantitative real time-PCR showed that the mRNA expression of occludin in the experimental group was significantly reduced as compared with the normal brain tissue at 6, 24, 48 and 72 h after the injection with statistically significant difference （P〈0.05）. Conclusion After intra-cerebral hemorrhage, as a major component of TJ of the BBB, occludin expression is down-regulated, which may be one of the most important molecular basis of disruption of BBB.

关 键 词：脑出血 血脑屏障 紧密连接 OCCLUDIN 

分 类 号：R285.5[医药卫生—中药学]