Matrix metalloproteinase and proinflammatory cytokine production by chondrocytes of human osteoarthritic cartilage: Associations with degenerative changes

Abstract

These results indicate that the superficial zone of OA cartilage specimens, which is characterized by fibrillations, chondrocyte clusters, and degenerative matrix changes, contains a variable proportion of cells that immunostain for IL-1beta, TNFalpha, and 6 different MMPs. These observations support the concept that cytokine-MMP associations reflect a modified chondrocyte phenotype and an intrinsic process of cartilage degradation in OA.