Fig. 5.

Roles of EVs in mitochondrial damage and oxidative stress. In the pathological state of chondrocytes, oxidative phosphorylation decreases and glycolysis increases, leading to mitochondrial dysfunction and oxidative stress. The role of EVs in this change can be divided into two modes. First, EVs from cartilage and endothelial cells carry endogenous substances to accelerate ROS accumulation and enhance chondrocyte metabolic disorder. Second, EVs in the state of oxidative stress carry a lot of pathological contents, which aggravate the progression of OA.