Immunopharmacological effect of β-d-mannuronic acid (M2000), as a new immunosuppressive drug, on gene expression of miR-155 and its target molecules (SOCS1, SHIP1) in a clinical trial on rheumatoid arthritis patients.

The positive impacts of β-d-mannuronic acid (M2000) on the gene expression of miR-155, its target molecules (SOCS1 and SHIP1), and NF-κB transcription factor were demonstrated in a study using the HEK293-TLR2 cell line. This new drug has been approved as a safe and effective medication by a randomized, multinational, phase III clinical trial on RA patients. The present study aimed to evaluate the oral administration effect of M2000 on the expression levels of the mentioned genes in RA patients. This research was conducted on 12 RA patients and 12 healthy individuals. After extraction of total RNA from PBMCs of patients and synthesis of cDNA, the expression levels of miR-155, SOCS1, SHIP1, and NF-κB genes were measured through quantitative Real-time PCR at baseline and after 12 weeks of M2000 therapy. Our findings showed that the miR-155 gene expression level significantly decreased in the M2000-treated patients compared with the baseline (0.76-fold, with p < .05). The expression levels of SOCS1 and SHIP1 genes significantly increased in the patients treated with M2000 compared with the before treatment (1.46-, 1.54-fold, with p < .01, p < .05, respectively). In addition, it was found that the gene expression level of the NF-κB transcription factor significantly reduced in M2000-treated patients compared with the baseline (0.81-fold, with p < .05). This study showed that the oral administration of M2000 was able to reduce the expression of the miR-155, increase the expression of SOCS1 and SHIP1, and decrease the NF-κB gene expression (Trial Registration Number: IRCT2017100213739N10).