Exosome modification to better alleviates endoplasmic reticulum stress induced chondrocyte apoptosis and osteoarthritis.

Osteoarthritis (OA) is characterized by cartilage matrix degeneration and chondrocyte apoptosis. Prolonged endoplasmic reticulum (ER) stress participates in chondrocyte apoptosis and cartilage degeneration in OA progression. miR-486-5p could suppress the apoptosis of nucleus pulposus cells and cardiomyocyte, yet whether miR-486-5p modified exosomes could modulate ER stress and apoptosis of chondrocytes remain unknown. We validated the increased inflammation and ER stress in OA synovium and cartilage, and the inhibition of ER stress could attenuate the IL-1β induced chondrocyte apoptosis. Administration of exogenous miR-486-5p could inhibit the ER stress, alleviate chondrocytes apoptosis and promote matrix regeneration. In comparison with direct administration of miR-486-5p and miR-486-5p overexpressing ADSCs, miR-486-5p modified exosomes indicated a better effect in modulating chondrocyte homeostasis. MiR-486-5p containing exosomes could also regulate macrophage polarization. Our IVIS imaging data validated that intraarticular injection of miR-486-5p containing exosomes could sustain for at least 7 days. MiR-486-5p containing exosomes showed a better effect on alleviating rats OA compared with direct administration of miR-486-5p and miR-486-5p overexpressing ADSCs. Our data demonstrated that miR-486-5p modified exosomes have a better effect on alleviating chondrocyte apoptosis and osteoarthritis. This study provides evidence of this efficient strategy of exosomal miRNA delivery and the miRNA-based therapy for OA.