Vascular endothelial cell-secreted exosomes facilitate osteoarthritis pathogenesis by promoting chondrocyte apoptosis.

Exosomes are major mediators of cell-to-cell communication, and are involved in many physiological and pathological processes. Recently, the roles of exosomes in osteoarthritis (OA) and their therapeutic potential have received increasing attention. Exosomes derived from vascular endothelial cells have been confirmed to participate in the occurrence and development of numerous diseases; however, their effects in OA have not been reported. Here, we demonstrated the roles of exosomes secreted by vascular endothelial cells in the development of OA. Through in vivo and in vitro experiments, we demonstrated that exosomes derived from vascular endothelial cells decreased the ability of chondrocytes to resist oxidative stress by inhibiting autophagy and p21 expression, thereby increasing the cellular ROS content and inducing apoptosis. These findings indicate that exosomes derived from vascular endothelial cells promote the progression of OA, thus, providing new ideas for the diagnosis and treatment of OA.