OBJECTIVE: To assess the association of single nucleotide polymorphisms (SNPs) of microRNA-146a (miR-146a) with clinical features of rheumatoid arthritis (RA). METHODS: In 126 patients with RA and 102 matched healthy controls, SNPs of miR-146a rs2910164 locus were determined with a high-resolution melting method. The association of such polymorphisms with disease activity score in 28 joints (DAS28) and clinical features of RA was assessed. RESULTS: The distribution of SNPs of miR-146a rs2910164 among RA patients did not differ from that of the control group. No significant association was found between miR-146a rs2910164 polymorphism with DAS28. However, RA patients with a GG genotype had a greater chance to develop extra-articular manifestations (P<0.01). CONCLUSION Polymorphisms of miR-146a rs2910164 locus is not an independent risk factor for RA, though its GG genotype may be associated with extra-articular manifestations of RA.
Arthritis, Rheumatoid ; genetics ; Case-Control Studies ; Genetic Predisposition to Disease ; Genotype ; Humans ; MicroRNAs ; genetics ; Polymorphism, Single Nucleotide

Objective·To investigate the expression of miR-146a in peripheral blood CD4+T lymphocytes of patients with rheumatoid arthritis(RA)and its correlation with inflammatory cytokines such as tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6).Methods·A total of 30 active RA patients who received medical treatment and 30 healthy controls who underwent physical examinations at the People's Hospital of Longhua,Shenzhen from August 2019 to July 2021 were selected.Peripheral blood mononuclear cells(PBMCs)and CD4+T lymphocytes were isolated from venous blood extracted from RA patients and healthy controls,respectively.Quantitative real-time PCR(qPCR)was used to detect the expression of miR-146a in peripheral blood CD4+T lymphocytes,and enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of TNF-α and IL-6.After transfection of the peripheral blood CD4+T lymphocytes of RA patients with miR-146a mimic,the expression of miR-146a,TNF-α and IL-6 was detected again.The correlations between miR-146a expression and TNF-α and IL-6 expression in RA patients,both before and after transfection,were analyzed by using Pearson correlation coefficient.Results·Before transfection with miR-146a mimic,the expression levels of miR-146a,TNF-α and IL-6 in peripheral blood CD4+T lymphocytes of RA patients were significantly higher than those of healthy controls(all P＜0.001).After transfection,the expression of miR-146a in peripheral blood CD4+T lymphocytes of RA patients was significantly higher,and the expression of TNF-α and IL-6 was significantly lower(all P＜0.001).The results of Pearson correlation analysis showed that the expression of miR-146a in peripheral blood CD4+T lymphocytes of RA patients,both before and after transfection,was positively correlated with the expression of TNF-α and IL-6,respectively(r=0.959,P＜0.001;r=0.916,P＜0.001;r=0.971,P＜0.001;r=0.861,P＜0.001).Conclusion·miR-146a can regulate the levels of TNF-α and IL-6 in peripheral blood CD4+T lymphocytes of RA patients,indicating that miR-146a may play a role in the pathogenesis of RA.