目的 研究microRNA-146a(miR-146a)在慢性免疫性血小板减少性紫癜(immune thrombocytopenic purpura,ITP)患者外周血单个核细胞(PBMC)的表达及其临床意义.方法 28例慢性ITP患者和28例健康对照者,荧光定量PCR(fluorescent quantitative PCR,FQ-PCR)检测PBMC中miR-146a的表达,ELISA检测血清中TNF-α、IL-2、IL-lβ和IFN-γ的表达水平;采用电转染技术将miR-146a前体(mimics)/抑制体(inhibitor)转染至ITP患者PBMC中,CCK-8法检测其对血小板诱导的细胞增殖反应的影响.结果 ITP患者PBMC的miR-146a表达较健康对照组显著降低,且与血小板计数呈正相关,与患者血浆TNF-α、IL-2和IFN-γ浓度呈负相关.转染miR-146a前体至ITP患者PBMC可抑制血小板诱导的IL-2合成以及PBMC增殖,转染miR-146a抑制体则可以促进IL-2的合成以及PBMC的增殖.结论 miR-146a参与了慢性ITP的发病机制,调控IL-2的表达,并介导了ITP患者PBMC的增殖,是慢性ITP潜在的治疗靶点.
Objective To investigate the increased expression of microRNA-146a(miR-146a) in peripheral blood mononuclear cells (PBMC) of patients with chronic immune thrombocytopenic purpura (ITP) and its clinical significance. Methods Twenty-eight patients with chronic ITP and 28 healthy controls matched with age and gender were enrolled in this study. Fluorescent quantitative PCR reaction was used to detect the relative expression of miR-146a in their PBMC. The serum concentration of TNF-α, IL-2,IL-1 β and IFN-γ were measured by ELISA. CCK-8 method was used to detect the proliferation ability of PBMC , which transfected with miR-146a mimics or inhibitor and then stimulated with platelet . Results The relative expression of miR-146a in ITP patients was higher than that of healthy controls. The increased expression of miR-146a was negatively correlated with the serum TNF-α, IL-2 and IFN-γ. The PBMC transfected with miR-146a mimics had reduced expression of IL-2 and proliferation when stimulated with platelet.In contrast, the opposite effect was observed with the miR-146a inhibitors transfection. Conclusion MiR146a was involved in the pathogenesis of chronic ITP by controlling IL-2 production and PBMC proliferation.Thus, it may be a potential therapy target for chronic ITP.