Upregulation of microRNA-93-5p/microRNA-4668-5p,and promoter methylation of matrix metalloproteinase-3 and interleukin-16 genes in Turkish patients with rheumatoid arthritis

Aim of the workTo investigate promoter methylation of matrix metalloproteinase-3 (MMP-3) and interleukin-16 (IL-16) genes with the expression of miRNA-93-5p and miRNA-4668-5p which target these genes in rheumatoid arthritis (RA), respectively.Patients and methodsThe study included 49 RA patients and 38 healthy controls. Promoter methylation of MMP-3 and IL-16 was analyzed by methylation-specific PCR. The expression of miRNA-93-5p and miRNA-4668-5p were determined. Disease activity score (DAS28) was assessed.ResultsThe 49 patients (38 female, 11 male) mean age was 50.4 ± 10.5 years and disease duration of 9.1 ± 7.4 years. The mean DAS28 was 3.9 ± 1.4. The MMP-3 gene methylation frequency was significantly lower in patients (n = 37;75.5%) compared to control (n = 37;97.4%) (p = 0.004) while they were comparable for IL-16 gene (n = 46;93.9% vs n = 37;97.4%)(p = 0.45). The relative normalized expression of miRNA-93-5p and miRNA-4668-5p were significantly increased (p < 0.001) in patients (2.28 ± 3.71 and 2.47 ± 4.17-fold) compared to controls (1.12 ± 0.18 and 1.28 ± 0.53-fold) and both tended to decrease with high disease activity (r =  ? 0.104, p = 0.52; r = ?0.24, p = 0.15, respectively). There was no significant difference of miRNA-93-5p (p = 0.45), and miRNA-4668-5p (p = 0.26) expressions between patients receiving treatment and those not. A negative correlation was observed between disease activity and change in expression levels of miRNA-93-5p (r = ?0.104, p = 0.52) and miRNA-4668-5p (r = ?0.24, p = 0.15). The ROC curve analysis of target miRNAs showed the diagnostic potential of miRNA-93-5p and miRNA-4668-5p (p = 0.003 and p < 0.001 respectively).ConclusionsThe methylation status of MMP-3 promoter and expression levels of miRNA-93-5p and miRNA-4668-5p could be useful biomarkers for the pathogenesis of RA and might reflect disease activity.