大鼠局灶性脑缺血再灌注血脑屏障超微结构及紧密连接蛋白Occludin变化的研究.doc

大鼠局灶性脑缺血再灌注血脑屏障超微结构及紧密连接蛋白Occludin变化的研究 f}I风与神经疾病杂志2007年8月第24卷第4期 文章编号:1003—2754(2007)040425—03 大鼠局灶性脑缺血再灌注血脑屏障超微结构 及紧密连接蛋白Occludin变化的研究 孙伟,杨鲲鹏,盛利,苏志强 ?425? 摘要:目的研究大鼠局灶性脑缺血再灌注模型血脑屏障(BBB)超微结构和Occludin的变化,探讨BBB 的结构改变及Occludin的表达异常在再灌注损伤中的作用.方法雄性Wistar大鼠,随机分成假手术组,缺血2h再 灌注3h,12h,24h,72h组,应用透射电镜,RT—PCR,免疫组化和WesternBlot等方法观察再灌注后不同时相缺血区 皮质BBB的超微结构,OccludinmRNA和白水平的变化.结果局灶性脑缺血再灌注后,缺血区皮质BBB的超 微结构受损,OccludinmRNA和蛋白表达水平下调.上述变化开始于再灌注后3h,再灌注24h达到高峰,72h开始减 弱.结论脑缺血再灌注过程中,BBB的超微结构损伤及Occludin的表达下降加重了缺血再灌注损伤. 关键词:脑缺血;再灌注损伤;血脑屏障(BBB);Occludin 中图分类号:R743文献标识码:A Astudyontheultrastructureofbloodbrainbarrierandtheexpressionofoccludininfocalbrainischemia—reperfu— sioninjuryratsSUNWei,YAN(;Kun—peng.SttENGLi,eta1.(DepartmentofNeurology,了’heFirstClinical ttospital()jHarbinMedicalUniversity,Harbin150001China Abstract:ObjectiveTostudytheultrastructureofbloodbrainbarrier(BBB)andtheexpressionofOC- cludininratswithfocalbrainischemiareperfusionandclarifytheeffectofchangesofBBBandOccludininreperfu— slonm’jury.MethodsMaleWistarratSwererandomlydividedintoshamoperatedgroupandischemia—reperfusion groups.Themodeloffocalbrainischemia—reperfusioninjurywasinducedbymiddlecerebralarteryocclusion (MCAO).After2hoursoftemporaryMCAO,ratswererespectivelysubjectedreperfusionof3hours,12hours,24 hoursand72hours.TheultrastructureofBBBwasobservedwithelectronmicroscope.Reversetranscrptionpoly— mersechainreaction(RT—PCR),immunohistochemistryandWesternblotwereusedtOdetectthelevelsofmRNA andproteinexpressionofOccludin.ResultsComparedwithsham—operatedgroup,ischemia—reperfusionsignifi— eantlydamagedthestructureofBBBanddecreasedtheexpressionofOccludinintheischemiccortexwhichbegan at3hoursafterreperfusion,peakedat24hoursandsubsidedat72hours.ConclusionsThisstudyindicatesthat boththedamageofBBBandthedecreaseofOccludinaggravateischemiareperfusioninjury. Keywords:Brainisehemia;Reperfusioninjury;Bloodbrainbarrier(BBB);Occludin 血脑屏障(BBB)是维持中枢神经系统内环境稳 定的重要结构,主要由毛细血管内皮细胞,基膜和星 形胶质细胞足板组成.其中,内皮细胞问的紧密连接 (TJ)是BBB结构与功能的主要基础.近年来研究表 明,BBB结构和功