Cell death in cartilage

Osteoarthritis (OA) is an aging-related disease that affects not only hyaline articular cartilage but all structures of weight-bearing joints. The disease process involves changes in the subchondral bone and is often associated with an inflammatory response. The central pathogenic events in OA are loss and abnormal remodeling of cartilage extracellular matrix. Chondrocytes constitute the only cell type of the articular cartilage. They maintain tissue homeostasis, respond to injury and perform the cartilage remodeling process that characterizes OA. Previous concepts on OA pathogenesis focused on the role of chondrocytes in the degradation of the extracellular matrix. More recent findings suggest that chondrocyte death and survival are closely linked to cartilage matrix integrity. This review discusses mechanisms and consequences of chondrocyte death.