miRNA-146a in rheumatoid arthritis: a new therapeutic strategy.

Evaluation of: Nakasa T, Shibuya H, Nagata Y, Niimoto T, Ochi M: The inhibitory effect of microRNA-146a expression on bone destruction in collagen-induced arthritis. Arthritis Rheum. 63(6), 1582-1590 (2011). miRNA-146a (miR-146a) has been shown to play an important role in the negative regulation of inflammatory innate immune responses, and is differentially expressed in a number of human diseases including rheumatoid arthritis. However, evidence for the potential therapeutic use of miR-146a in human disease has been lacking. The current paper demonstrates the potential therapeutic application of miR-146a for rheumatoid arthritis by demonstrating the inhibitory effect of miR-146a on osteoclastogenesis in vitro. Moreover, using a collagen-induced arthritis mouse model, they were able to demonstrate that intravenous administration of double-stranded miR-146a resulted in the suppression of cartilage and bone destruction, despite relatively unaffected immune cell infiltration of the synovium and inflammatory cytokine expression.