MiRNA-Mediated Regulation in Osteoarthritis Across Joint Tissues, Including Translational Perspectives in Dogs.

Osteoarthritis (OA) is increasingly conceptualized as a whole-joint disorder, in which pathological processes across articular cartilage, subchondral bone, synovium, and periarticular tissues are tightly interconnected. Within this context, miRNAs have emerged as central post-transcriptional regulators capable of integrating mechanical, inflammatory, and metabolic cues at the network level. In human OA, extensive evidence links miRNA dysregulation to cartilage catabolism, impaired stress adaptation, inter-tissue communication, and the emergence of extracellular and circulating miRNA (cmiRNA) signatures with diagnostic and translational relevance. In contrast, miRNA research in canine OA remains limited, despite dogs developing a naturally occurring form of the disease that closely mirrors human OA in clinical presentation, joint pathology, and biomechanical drivers. To date, only a single pilot study has systematically investigated miRNA expression in spontaneous canine OA, underscoring both the feasibility of miRNA profiling and the substantial gaps that persist in tissue validation and functional characterization. This review critically synthesizes miRNA-mediated regulatory mechanisms in human OA and leverages this evidence to define research priorities in canine OA, where experimental validation remains limited. By focusing on shared molecular contexts rather than assumed equivalence, the review defines a comparative framework highlighting cmiRNAs as promising non-invasive translational targets.