rt-pcr_Changes of fight junction protein occludin expression

  本文关键词：紧密连接蛋白，，由笔耕文化传播整理发布。

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occludin mRNA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48 h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24～72h occludin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occludin mRNA相对含量明显降低,在6～72 h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.

Abstract： 

Objective To investigate the changes of tight junction (TJ) protein occludin expression between the mierovascular 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 intraeerebral 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 impotant molecular basis of disruption of BBB.

  本文关键词：紧密连接蛋白，由笔耕文化传播整理发布。