Treg细胞及TGFβ-1免疫调节功能紊乱加重小鼠缺血性脑损伤  

Imbalance of immunological functions of Treg and TGF-β1 aggravated cerebral ischemia damage in mice

作　　者：杨双文[1] 曹丽[1] 杨双武[2] 王世全[1] 贾文元[1] 汪晨[1] 

机构地区：[1]第四军医大学西京医院麻醉科,陕西西安710032 [2]第四军医大学西京医院神经外科,陕西西安710032

出　　处：《细胞与分子免疫学杂志》2011年第4期408-411,共4页Chinese Journal of Cellular and Molecular Immunology

基　　金：国家自然科学基金资助项目(30872445)

摘　　要：目的:通过检测小鼠短暂性脑缺血(tMCAO)后不同时间点CD4+CD25+调节性T细胞(Treg)比例及血清TGF-β1浓度变化,探讨其免疫调节功能在缺血性脑卒中炎性损伤中作用。方法:60只昆明小鼠随机分为6组,假手术组(sham组,24 h)10只,缺血再灌注后12 h、24 h、48 h、72 h及5 d五个tMCAO组(n=10/组)。采用腔内线栓法建立小鼠tM-CAO模型;tMCAO组在再灌注后各时间点进行神经功能缺陷评分(NDS),其后处死小鼠行氯化三苯基四氮唑(TTC)染色观察脑梗死容积变化;同期免疫荧光染色观察脾脏中Foxp3表达;提取脾脏单个核细胞,流式细胞术(FCM)测定Treg在单个核细胞中比例;分离血清,ELISA检测血清中TGF-β1浓度。结果:缺血再灌注12 h脑部炎性损伤明显,且逐渐加重,TTC染色示炎症反应中心脑梗死面积同期增大,缺血再灌注48 h达高峰,此后前述表现逐渐减小;随再灌注时间延长,神经功能也逐渐改善。Foxp3在各组小鼠脾脏中均有阳性表达,但存在明显差异;FCM分析发现,缺血再灌注24 h时Treg比例较sham组明显减少(P<0.05),但在72 h时Treg基本恢复正常,5 d时则明显高于sham组(P<0.05)。血清中TGF-β1浓度与Treg有相似表现,再灌注24 h时降低明显,48 h则恢复至sham组水平,而在5 d时高出sham组(P<0.05)。并且Treg与TGF-β1呈正相关。结论:在缺血性脑损伤急性期Treg与TGF-β1明显减少,而在恢复期二者大量增加,且与脑梗死容积变化紧密相关,说明缺血性脑损伤后Treg与TGF-β1功能失衡在急性缺血性脑卒中炎性损伤中发挥着重要作用。AIM：To investigate the changes of proportion of CD4＋CD25＋ regulatory T cells（Treg） in Splenocytes and concentration of serum TGF-β1 in diverse period after transient middle cerebral artery occlusion（tMCAO） in mice and correlation between Treg and TGF-β1,so as to elucidate their roles in the immunological injury of acute ischemic stroke.METHODS： 60 male Kunming mice were randomly divided into six groups,i.e.sham group（24 h,n=10） and five tMCAO groups（ischemia/reperfusion 12 h,24 h,48 h,72 h and 5 d,n=10/group）,amount to six groups.The models of tMCAO were established by modified monofilament method;Neurologic deficit score was performed at each time point after tMCAO,and then,to sacrifice mice and measure the volume of cerebral infarction by TTC staining;the expression of Foxp3 in spleen was observed by frozen section and immunofluorescence method;the proportions of Treg in splenocytes were analyzed by flow cytometry（FCM） and the concentrations of serum TGF-β1 were measured by ELISA.RESULTS： This study observed that there was obvious immunological injury and it was gradually worse.Similarly,TTC staining indicated that the volume of cerebral infarction gradually enlarged and peaked at 48 h following reperfusion,subsequently,exhibited slight decrease.Neurological function gradually improved after reperfusion.There were positive expressions of Foxp3 in the mice spleens and significant different in every groups.FCM indicated,compared with sham group,the percentage of Treg was decrease at 24 h after ischemia/reperfusion（P0.05）,and recovered normal level at 72 h,and significantly increased at 5 d（P0.05）.The level of serum TGF-β1 also showed the similar tendency,the concentration of serum TGF-β1 was lower at 24 h after ischemia/reperfusion than sham group,and recovered to sham＇s level at 48 h,and was significantly higher at 5 d than sham group（P0.05）.Otherwise,there was a positive correlation between serum level of TGF-β1 and percentage of Treg.CONCLUSION： The levels of

关 键 词：脑缺血 炎症 调节性T细胞 转录因子FOXP3 转化生长因子Β 

分 类 号：R392.11[医药卫生—免疫学]