Synovial mesenchymal stem cell-derived exosomal miR-320c enhances chondrogenesis by targeting ADAM19

Background: Synovial mesenchymal stem cell (SMSC)-derived exosomes show treatment potential in osteoarthritis, although their functional mechanism is still unclear. Materials & methods: Osteoarthritis chondrocytes and normal SMSC were cultured. Subsequently, chondrocytes were co-cultured with SMSC or miR-320c-overexpressing SMSC-derived exosomes, or directly transfected with miR-320c mimic. Furthermore, compensate experiments were conducted. Results: SMSC promoted chondrocyte proliferation, migration, COL2A1 and ACAN expressions while suppressing apoptosis by transmitting exosomes. Furthermore, miR-320c-overexpressing SMSC-derived exosomes and direct miR-320c overexpression in chondrocytes presented more significant effect on enhancing chondrogenesis. In addition, miR-320c directly targeted ADAM19, and ADAM19 overexpression compensated the regulation of miR-320c on chondrogenesis. Conclusion: SMSC-derived exosomal miR-320c enhances chondrogenesis through targeting ADAM19, highlighting a potentially novel mechanism of SMSC in treating osteoarthritis.