摘要：为探讨重症肌无力（myasthenia gravis，MG）患者血清miR-126、叉头翼状螺旋转录因子3(forkhead box P3，Foxp3）mRNA的表达及临床意义，为MG发病机制研究提供更多的依据，选择63例MG患者为MG组，50例体检正常者为对照组。采用RT-PCR检测血清miR-126、Foxp3 mRNA的表达水平，并采用Spearman相关性分析法分析miR-126与Foxp3 mRNA的相关性。结果显示，MG组患者血清miR-126的相对表达量(2.59±0.84)高于对照组(1.05±0.73，P < 0.01），而Foxp3 mRNA的相对表达量(1.58±0.81)低于对照组(3.15±0.96，P < 0.01)；miR-126核苷酸序列在人、小鼠、狗等7个物种间存在高度保守性；MG组患者血清miR-126与Foxp3 mRNA呈负相关(r=－0.852，P < 0.01)。提示MG患者存在miR-126及Foxp3 mRNA的差异表达，且高表达的miR-126可能通过抑制Foxp3 mRNA的表达参与MG的致病。

The purpose of this study was to investigate the expression and clinical significance of miR-126 and forkhead box P3 (Foxp3) mRNA in peripheral blood of patients with myasthenia gravis (MG), for better understanding of the pathogenesis of MG. 63 patients with MG were enrolled as the MG group and 50 healthy persons were selected as the control group. RT-PCR was used to detect the expression levels of miR-126 and Foxp3 mRNA in peripheral blood of the two groups, and the correlation between miR-126 and Foxp3 mRNA was analyzed by Spearman correlation analysis. The results showed that the expression of miR-126 in peripheral blood of the MG group (2.59±0.84) was higher than that of the control group (1.05±0.73, P < 0.01), while the relative expression of Foxp3 mRNA (1.58±0.81) was lower than that of the control group (3.15±0.96, P < 0.01). The miR-126 nucleotide sequence was highly conserved among 7 species including human, mouse and dog. There was a negative correlation between miR-126 and Foxp3 mRNA in peripheral blood of the MG group (r=-0.852, P < 0.01). The results indicate that differential expression profiles of miR-126 and Foxp3 mRNA exist in MG patients, and the highly expressed miR-126 may participate in the pathogenesis of MG by inhibiting the expression of Foxp3 mRNA.