IL1B and osteoarthritis, knee: Intra-articular injection of UC-MSC-Exos in OA rat models reduced the levels of cytokines (TNF-α, IL-1β, and IL-6) in the synovial fluid, decreased the expression of MMP-13 and ADAMTS-5 in chondrocytes stimulated by IL-1β, and increased the expression of Col2 in chondrocytes, thereby promoting cartilage regeneration.260 Furthermore, Exos derived from human synovial mesenchymal stem cells overexpressing miR-140-5p were reported to enhance cartilage tissue regeneration and prevent knee osteoarthritis in a rat model.261