胸腺素β4通过提高Akt磷酸化促进局灶脑缺血/再灌注大鼠大脑皮质eNOS和CD31表达  

Thymosinβ4 improves CD31 and eNOS expression in rat cerebral cortex after focal cerebral ischemia/reperfusion through up-regulating phosphorylating level of Akt

作　　者：庞月珊[1] 罗勇[1] 谢宸宸[1] 李满[1] 陈瑞芳[1] 汶海琪 

机构地区：[1]重庆医科大学附属第一医院 神经内科 重庆市神经病学重点实验室,重庆400016

出　　处：《基础医学与临床》2014年第7期921-926,共6页Basic and Clinical Medicine

基　　金：教育部高等学校博士学科点专项科研基金(20095503110001);重庆市卫生局中医药科研项目(渝中医2005-B-24);重庆市卫生局中医药重点科技项目(ZY20131027)

摘　　要：目的探讨胸腺素β4(Tβ4)对局灶脑缺血/再灌注大鼠大脑皮质血管再生影响及其机制。方法用线栓法制备大鼠局灶脑缺血/再灌注模型。将大鼠随机分为假手术组(S组)、模型组(IR组)、Tβ4组(IRT组)、Tβ4+LY294002组(IRTL组)、0.9%氯化钠注射液组(IRN组),缺血2 h后把IR、IRN和IRT组分为3和7 d两亚组。Western blot检测Akt磷酸化水平和eNOS蛋白表达;免疫组化检测Tβ4和CD31蛋白表达;荧光定量PCR检测eNOS、SDF-1及CXCR4 mRNA表达;Longa法检测神经功能。结果与IRN组相比,IRT 3 d Tβ4蛋白表达显著增多(P<0.01);与IRN组比较,IRT 3和7 d Akt磷酸化水平和eNOS蛋白显著增高(P<0.05),但IRTL组与其比较p-Akt和eNOS蛋白表达显著减少(P<0.01);与IRN组比较,IRT 3和7 d eNOS、SDF-1和CXCR4 mRNA表达显著升高(P<0.05);与IRN组比较,IRT 3和7 d组微血管密度显著增高(P<0.05),大鼠神经功能缺损在第7天改善最明显(P<0.05)。结论 Tβ4可能通过提高局灶脑缺血/再灌注大鼠大脑皮质Akt磷酸化水平、eNOS基因和蛋白的表达,促进大鼠大脑皮质缺血半暗带血管再生和神经功能恢复。Objective To investigate the effect and mechanism of thymosin beta4 （Tβ4） on angiogenesis in rat cerebral cortex after focal cerebral ischemia/reperfusion.Methods Rats were randomly divided into sham group（S）,model group（IR）,Tβ4 group（IRT）,Tβ4 ＋ LY294002 group（IRTL） and 0.9% sodium chloride injection group （IRN）.The focal ischemia/reperfusion rat model was established by filament occluding the right middle cerebral artery for 2 hours.Rats were divided into 3 day and 7 day subgroups in IR,IRN and IRT group.The protein expression of eNOS,p-Akt and Akt were detected by western blotting.Immunohistochemical method was applied to detect the expression of Tβ4 and CD31.The mRNA expression of eNOS,SDF-1 and CXCR4 was tested by fluorogenic quantitative PCR.Longa score was selected to evaluate neurobehavioral.Results Compared with IRN group,the protein expression of Tβ4 increased significantly at IRT 3 day （P 〈 0.01） ; the protein expression of eNOS,p-Akt significantly increased at IRT 3 and 7 day （P 〈 0.05）,but in IRTL group they reduced significantly （P 〈 0.01） ; compared with IRN group,the mRNA expression of eNOS,SDF-1 and CXCR4 were increased significantly at IRT 3 and 7 day （P 〈0.05） ; The number of CD31 postive micrangium increased significantly at IRT 3 and 7 day （P 〈 0.05） and the neural function recovery significantly at IRT 7 day （P 〈 0.05）.Conclusions Tβ4 may promote angiogenesis and behavioral recovery by increasing p-Akt and eNOS expression in a rat model of focal cerebral ischemia/reperfusion.

关 键 词：胸腺素Β4 局灶脑缺血 再灌注 血管再生 ENOS PI3K Akt 

分 类 号：R743.33[医药卫生—神经病学与精神病学]