DDIT3 and osteoarthritis: • Protected the mitochondrial function, hence prevented cartilage degeneration•improves age-related and surgically induced osteoarthritis by promoting autophagy•Inhibited apoptosis of chondrocytes through activation ERK1/2 signaling Pathways induced autophagy•Inhibited the PERK-eIF2α-CHOP pathway through promoting SIRT1 expression in oxidative stress