Recombinant human inteleukin-1 inhibits plasminogen activator inhibitor-1 (PAI-1) production by human articular cartilage and chondrocytes

Abstract

Human articular cartilage and chondrocyte monolayers in culture constitutively produced plasminogen activator inhibitor-1 (PAI-1) protein and mRNA, as assessed by a specific enzyme-linked immunosorbent assay and Northern blotting analysis, respectively. Recombinant human interleukin-1 (IL-1) invoked a dose-dependent inhibition of PAI-1 production in both cartilage and chondrocyte cultures. The inhibitory effect of IL-1 was observed between 2-8h after addition of the cytokine, while the optimal dose was between 10-100U/ml IL-1α (57-570pM IL-1α). Results obtained by Northern analysis of chondrocyte total RNA reflected those found for the PAI-1 antigen, namely, that nontreated chondrocytes show..