重症肌无力胸腺Foxp3基因转录表达水平及其临床意义

目的 探讨抑制性转录调节因子Foxp3在重症肌无力(myasthenia gravis, MG)胸腺内表达及其临床意义.方法 收集本科2003年1月至2006年6月手术切除的MG胸腺组织50例,采用免疫组织化学、Western blot以及RT-PCR技术,检测Foxp3在胸腺内组织定位,蛋白及mRNA转录表达水平以及与MG胸腺病理、临床特征间关系.结果 Foxp3阳性细胞主要位于胸腺内髓质及血管周围间质,少量见于皮质区;MG胸腺组织中Foxp3显著低于对照胸腺组织;其中胸腺瘤组织中仅有少量表达,与增生胸腺差异显著;Foxp3表达水平与MG临床分型负相关.结论 MG胸腺Foxp3基因转录与表达异常,可能参与MG自身免疫的发生.

Decreased expression of Foxp3 in myasthenic thymus and thymoma

Objective To explore the changes of Foxp3 expression in myasthenic thymus and thymoma.Methods Thymic specimens and clinical data of 50 myasthenia gravis(MG)patients who underwent thymectomy from January 2003 to June 2006 were collected,classified into three types according to MGFA clinical classification:hyperplastic thymus,atrophic thymus and thymoma.The thymic tissues collected near the thymoma served as thymic specimens near thymoma.The normal thymic tissues excised in cardiac surgery were used as control.The levels of Foxp3 mRNA and protein,as well as their relationship with clinical characteristics,were examined by immunohistochemistry,Western blotting and RT-PCR.Results Foxp3 positive cells mainly located in the medulla of myasthenic thymus and mesenchyma around blood vessels,less in cortical area.The levels of Foxp3 mRNA and protein were significantly lower in myasthenic thymus than that of non-myasthenic control specimens,much less in the specimens of thymoma with a significant difference between them and that of hyperplastic thymus.The levels of Foxp3 mRNA and protein were negatively associated with MGFA clinical classification.Conclusion Foxp3 expression decreased in myasthenic thymus and thymoma,indicating a role of Foxp3 in etiology of MG.