ABSTRACT
Rheumatoid arthritis (RA) is a polygenic autoimmune disorder with an uncertain etiology, primarily impacting the joints. Moreover, the disease may manifest beyond articular involvement, leading to extra-articular manifestations. Fibroblast-like synoviocytes (FLS) are cells of mesenchymal origin that possess crucial physiological significance within the synovium, contributing to the synthesis of specific constituents found in the synovial fluid and articular cartilage. Consequently, there has been a growing focus on FLS as a potential therapeutic target in the context of RA. Recent investigations have revealed that non-coding RNAs (ncRNAs) serve as pivotal regulators of FLS function, with their dysregulated expression patterns being detected within FLS populations. NcRNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), assume essential functions as regulators of gene expression at both the post-transcriptional and transcriptional levels, and also serve as guiding molecules for chromatin-modifying complexes. Majority of these ncRNAs contribute to various FLS activities including metastasis, proliferation, and cytokine production. In the current work, we comprehensively review the existing literature on ncRNAs, which play pivotal roles in FLS activity and the pathogenesis of RA. Furthermore, this study provides a comprehensive summary and description of the lncRNA/circRNA-miRNA-mRNA regulatory axes in FLS activity, along with potential implications for the RA development. As well, in the final section, we illustrated that therapeutic agents including herbal medicine, and exosomes by modulating ncRNAs regulate FLS activity.
