Fig. 2
From: Extracellular vesicles in the pathogenesis of rheumatoid arthritis and osteoarthritis
Proposed mechanism of EV communication between FLS and chondrocytes in OA. EVs from FLS stimulated with inflammatory cytokines in the synovial fluid are released into the synovial fluid act on chondrocytes to increase MMP-13 and ADAMTS-5. EVs from chondrocytes stimulated with inflammatory cytokines are released into the joint space and increase MMP-13, COX-2, IL-1β, and TNF-α. This positive feedback cycle leads to further breakdown of the articular cartilage ECM. COX-2 cyclooxygenase 2, ECM extracellular matrix, EV extracellular vesicle, miRNA microRNA, MMP matrix metalloproteinase