Osteopontin: An intrinsic inhibitor of inflammation in cartilage

Abstract

The data indicate that one of the functions of intraarticular OPN, which is overexpressed in OA cartilage, is to act as an innate inhibitor of IL-1, NO, and PGE2 production. These findings suggest that the production of pleiotropic mediators of inflammation that influence cartilage homeostasis, such as NO and PGE2, is regulated by the interaction of chondrocytes with differentially expressed proteins within the extracellular matrix.