MicroRNAs in Synovial Pathology Associated With Osteoarthritis

Abstract

Osteoarthritis (OA) is the most common type of arthritis, a disease that affects the entire joint. The relative involvement of each tissue, and their interactions, add to the complexity of OA, hampering our understanding of the underlying molecular mechanisms, and the generation of a disease modifying therapy. The synovium is essential in maintaining joint homeostasis, and pathologies associated with the synovium contribute to joint destruction, pain and stiffness in OA. MicroRNAs (miRNAs) are post-transcriptional regulators dysregulated in OA tissues including the synovium. MiRNAs are important contributors to OA synovial changes that have the potential to improve our understanding of OA and to act as novel therapeutic targets. The purpose of this review is to summarize and integrate current published literature investigating the roles that miRNAs play in OA-related synovial pathologies including inflammation, matrix deposition and cell proliferation.

Keywords: fibrosis; inflammation; microRNA; osteoarthritis; synovium.

Figure 1

Schematic showing some miRNAs involved in human OA synovial pathology. MiR-381a-3p, miR-34a, miR-146a, and miR-181a promote inflammatory mechanisms (32, 33). MiR-26a-5p, miR-146a, miR-122, and miR-181c suppress the expression of inflammatory cytokines (24, 26, 27, 31). MiR-181c and miR-770 suppress fibroblast-like synoviocyte proliferation (24, 25). MiR-29a and miR-338-3p exhibit anti-fibrotic effects (34, 35).