Background MicroRNAs (miRNAs) are a 21 to 25 nucleotide long, small non-coding RNAs that post-transcriptionally regulate the expression of target genes, and thus modulate biological processes including cell differentiation, proliferation, apoptosis and invasion.

Objectives The aim of the study was to examine the relation among miR-124 and serum levels of selected cytokines and chemokines (IL-6, IL-13, IL-15, TNF-alpha, MCP-1, RANTES), MMP (MMP-3), production of auto-antibodies, and factors describing rheumatoid arthritis (RA) including DAS28 and Total Sharp score.

Methods A total of 80 RA patients according to the ACR criteria, and 10 control subjects were recruited into the study. The measurements of miR-124 and U-6 expression, CRP, anti-CCP, presence of rheumatoid factors (RFs), radiographs of both hands with calculation of Total Sharp score (TSS), DAS28 and cytokines, chemokines and MMP levels in serum were obtained from all RA patients.

Results miR-124 was down-regulated in RA patients compared to controls. The miR-124 expression correlated to MMP-3 levels (p < 0.001). No relation of miR-124 expression to measures of RA activity (DAS28 score, p = 0.51; TSS, p = 0.89; X-ray stage, p = 0.58) and auto-antibodies (anti-CCP, p = 0.14; RF, p = 0.29; RF IgG, p = 0.63; RF IgA, p = 0.92; RF IgM, p = 0.70) was observed. Also no association to acute inflammatory markers (CRP, p = 0.25; IL-6, p = 0.91), other cytokine and chemokines (IL-13, p = 0.62; IL-15, p = 0.57; IL-8, p = 0.78; MCP-1, p = 0.37; RANTES, p = 0.47) was found.

Conclusions In conclusion, we present a down-regulation of miR-124 in RA patients and its correlation to MMP-3 levels.

Disclosure of Interest None Declared