Correlations between miR-223/mTOR/S6K pathway and RA activity and antibody levels

Abstract

Abstract Objective: To investigate the expression levels of miR-223 and mTOR/S6K pathways in synovial tissues of rheumatoid arthritis (RA) and their correlation with disease activity and antibody levels. Methods: 17 hospitalized patients with moderate to severe disease RA were selected. During the same period, 9 patients hospitalized for knee osteoarthritis (OA) operation were involved. The synovial tissue of the knees was obtained under the guidance of ultrasound in RA group and obtained by orthopedic surgeons in OA group. The expression levels of mTOR, S6K, RPS6 mRNAs and miR-223 level in the synovial tissue were detected by QRT-PCR. The differences of miR-223 level and the mRNA levels of mTOR, S6K and RPS6 between the two groups were analyzed. The correlations between the level of miR-223 and the mRNA levels of mTOR, S6K and RPS6 were analyzed and the correlations between miR-223 level, the levels of mTOR, S6K, RPS6 mRNA and anti-CCP antibody and disease activity indicators were also analyzed in RA group. Results: The miR-223 level in RA group was significantly increased compared with OA group (P<0.05), and the mRNA levels of S6K and RPS6 in RA group were significantly decreased compared with OA group (P<0.05). The miR-223 level in RA group was negatively correlated with the mRNA levels of S6K and RPS6 (P<0.05), but there was no significant correlation between miR-223 level and the level of mTOR mRNA (P>0.05). The levels of miR-223 and mTOR mRNA in RA group were negatively correlated with the serum anti-CCP antibody level (P<0.05), and the level of RPS6 mRNA was positively correlated with the anti-CCP antibody level (P<0.05). The miR-223 level in RA group was positively correlated with the serum CRP level (P<0.05). RPS6 mRNA level was negatively correlated with CRP level (P<0.05). Conclusion: Abnormal miR-223/mTOR/S6K pathway exists in the synovial tissue of RA knee joints, which is correlated with the levels of anti-CCP antibody and CRP, indicating the direction for further research on the pathogenesis of RA.