microRNA-146a, TRAF6 gene and IRAK1 gene expressions in the peripheral mononuclear cells of patients with ankylosing spondylitis / 中华风湿病学杂志

ABSTRACT

Objective To investigate the expression of micro RNA-146a (miR-146a),TNF receptorassociated factor 6 (TRAF6) gene and IL-1 receptor-associated kinase 1 (IRAK1) gene in the peripheral mononuclear cells (PBMCs) of patients with ankylosing spondylitis (AS) and their relationship with the disease activity.The role of miR-146a,TRAF6,IRAK1 in the pathogenesis of AS was explored.Methods Expression of miR-146a,TRAF-6 and IRAK-1 in peripheral blood mononuclear cells was studied using realtime polymerase chain reaction (qRT-PCR) in 45 AS patients and 22 healthy controls.The indicators of disease activity adopted in this study were Bath ankylosing spondylitis disease activity index (BASDAI),erythrocyte sedimentation rate (ESR),C-reactive protein (CRP) level,and immunoglobulin (Ig).The relationship was analyzed in AS patients between the relative expression levels miR-146a,TRAF6,IRAK1 and BASDAI,ESR,CRP,Ig concentration.Non-parametric test,t test,One-way ANOVA,Pearson's and Spearman's correlation analysis were used for statistical analysis.Results ①The relative expression level of miR-146a which was observed in PBMCs of AS patients was significantly higher than that in normal control group [1.46(0.39,4.79)and 0.81(0.17,1.90),P＜0.05].The expression of miR-146a was significantly higher in active AS patients group than that in inactive patients [2.93(0.95,7.95) and 0.54(0.28,1.69),P＜0.05],there was no difference between the treatment group and without treatment group [1.28(0.31,2.37) and 2.22(0.49,7.71),P＞0.05].② There was significant difference in the relative expression level of IRAK-1 between AS patients and the normal control group.IRAK1 was significantly higher in AS patients than that in normal control group (1.4±0.7,1.1±0.4,P＜0.05).However,there was not difference between active AS patients group and inactive patients group as well as treated group and untreated group (1.5±0.9,1.4±0.5; 1.6±0.7,1.3±0.7,P＞0.05).③ TRAF6 expression was obviously lower in AS patients than that in normal control group (1.3±0.6,1.7±0.8,P＜0.05),and that was also significantly lower in the untreated group and active group than that in the normal control group (1.1±0.7,1.7±0.8; 1.1±0.5,1.7±0.8,P＜0.05).④ Signi-ficant positive correlation was observed between the miR-146a level and BASDAI,as well as duration of morning stiffness (r=0.557,P=0.000; r=0.363,P=0.018).The expression level of IRAK1 was significantly negative correlated with IgM (r=-0.313,P=0.046).Conclusion ① miR-146a expression is up-regulated in patients with AS,and it may be a potential useful marker for disease activity in AS patients; ② The abnormal expression of IRAK1,TRAF6 in AS patients may play a role in the pathogenesis of AS.