The role of β-d-mannuronic acid, as a new non-steroidal anti-inflammatory drug on expression of miR-146a, IRAK1, TRAF6, NF-κB and pro-inflammatory cytokines following a clinical trial in rheumatoid arthritis patients.

miR-146a, its targets (IRAK1, TRAF6) and NF-κB transcription factor play a fundamental role in rheumatoid arthritis (RA). Positive effects of drug β-d-mannuronic acid (M2000) were proven on their expression in the HEK-Blue hTLR2 cell line, and results of its phase III clinical trial on RA patients were encouraging. This research aimed to investigate the effects of M2000 on expression of these genes and serum levels of IL-6 and TNF-α as pro-inflammatory cytokines in RA patients. In this study (Trial Registration Number: IRCT2017100213739N10), 12 RA patients (according to the American College of Rheumatology criteria) and 12 healthy subjects (as control group) were selected. The gene expression of miR-146a, IRAK1, TRAF6, and NF-κB were measured at the baseline and after 12 weeks M2000 therapy, using quantitative real-time PCR method. Moreover, the serum levels of IL-6 and TNF-α were evaluated at the similar times by ELISA method. Our findings showed that the gene expression of miR-146a, IRAK1, TRAF6, and NF-κB significantly decreased after 12 weeks M2000 therapy in RA patients (0.81-, 0.68-, 0.79-, 0.82-fold, with  < .05,  < .01,  < .01,  < .05, respectively). Furthermore, the serum levels of IL-6 and TNF-α significantly reduced in these patients after 12 weeks M2000 therapy (both with  < .05). The present research results determined the part of molecular mechanisms of drug M2000 in RA treatment, based on the expression and function modification of miR-146a, IRAK1, TRAF6, NF-κB, IL-6 and TNF-α.