Freshly isolated osteoarthritic chondrocytes are catabolically more active than normal chondrocytes, but less responsive to catabolic stimulation with interleukin‐1β

Abstract

Our study confirms that IL-1beta activity is critically dependent on both the applied concentration and the reactivity of the cells stimulated. The responsiveness appears to be significantly reduced in late-stage osteoarthritic chondrocytes. However, these cells show high basic expression levels of catabolic enzymes and mediators. Thus, it remains open whether our data indicate that osteoarthritic chondrocytes are per se not responsive to IL-1beta or are already so strongly stimulated (e.g., by IL-1) during the disease process that they are refractory to further stimulation.