中文摘要：

目的研究人脐带血间充质干细胞（MSC）移植对大鼠局灶性脑缺血再灌注损伤炎性因子表达和调节性T细胞（Treg）数量及神经功能缺损的影响。方法选择健康雄性SD大鼠40只,随机分为假手术组、缺血再灌注组、MSC组、生理盐水组,每组10只。于缺血前、缺血后30min、缺血再灌注2、3、6h测定血清白细胞介素（IL）-6、干扰素γ（IFNγ）、IL-10、转化生长因子β（TGF-β）水平变化,于1、3、7、14d对大鼠神经功能进行评分,并检测外周血中Treg表达。结果 MSC组缺血后IL-6、IFNγ水平升高,分别在缺血再灌注2h、缺血后30min达高峰,显著小于缺血再灌注组和生理盐水组;缺血后缺血再灌注组和生理盐水组IL-10、TGF-β水平降低,MSC组升高。MSC组缺血再灌注3、7、14d神经功能缺损评分明显低于缺血再灌注组和生理盐水组（P〈0.05）。结论人脐带血MSC移植可促进缺血再灌注大鼠神经功能恢复,诱导CD4CD25Treg细胞增殖,促炎性因子IL-6、IFNγ水平下降,抗炎性因子IL-10、TGF-β水平升高,从而减轻缺血性脑损伤。

英文摘要：

Objective To study the effect of human umbilical cord blood mesenchymal stem cells（hUCB-MSCs）transplantation on expression of inflammatory cytokines,number of regulatory T cells,and nerve function defect in rats following focal cerebral ischemia reperfusion（I/R）injury.Methods Forty healthy male SD rats were randomly divided into sham operation group,I/R group,MSC group and saline group（10in each group）.Their serum levels of IL-6,IFNγ,IL-10 and TGF-βwere measured before ischemia,30 min after ischemia,and 2,3,6hafter reperfusion.Their nerve function was scored and expression of regulatory T cells in peripheral blood was detected on days 1,3,7and 14 respectively after reperfusion.Results The serum IL-6and IFNγlevel increased and reached its peak at 2hafter I/R and 30 min after ischemia respectively,and was significantly lower in MSC group than in I/R group and saline group.The serum IL-10 and TGF-βlevel decreased in I/R group and saline group and increased in MSC group after reperfusion.The nerve function defect score was significantly lower in MSC group than in I/R group and saline group on days 3,7and 14 after reperfusion（P〈0.05）.Conclusion hUCB-MSC transplantation can ameliorate ischemic brain injury by promoting the recovery of nerve function,inducing the proliferation of CD4CD25 regulatory T cells,decreasing the IL-6and IFNγlevel,and increasing the IL-10 and TGF-βlevel.