Cordycepin inhibits IL-1β-induced MMP-1 and MMP-3 expression in rheumatoid arthritis synovial fibroblasts

Objective. MMP is a key enzyme in the degradation of extracellular matrices, and its expression plays important roles in inflammatory diseases. Cordycepin (3′-deoxyadenosine), a bioactive compound of Cordyceps militaris, has been shown to exhibit many pharmacological activities, such as anti-cancer, anti-inflammatory and anti-infection activities. In this study, we aimed at the inhibitory effect of cordycepin on IL-1β-induced MMP-1 and MMP-3 expression as well as the molecular basis using RA synovial fibroblasts (RASFs). Methods. RASFs were isolated from synovial tissue obtained from 12 patients with RA and cultured in monolayer. Expression of MMP-1 and MMP-3 was evaluated using western blotting and real-time PCR. Chemokines were analysed by ELISA. The phosphorylation of mitogen-activated protein kinase was measured by western blotting. Electrophoretic mobility shift assay was performed to evaluate binding activities of DNA to nuclear factor-κB (NF-κB) and activator protein-1 (AP-1). Results. Cordycepin inhibited IL-1β-induced MMP-1 and MMP-3 expressions in RASFs in a dose-dependent manner. Among various chemokines [such as monocyte chemoattractant protein-1 (MCP-1), GRO-α, regulated upon activation, normal T-cell expressed and presumably secreted (RANTES) and epithelial neutrophil activating peptide 78 (ENA-78)], cordycepin specifically blocked IL-1β-induced ENA-78 production in RASF. Moreover, cordycepin significantly inhibited IL-1β-induced p38/JNK and AP-1 activation, but not extracellular signal-regulated kinase (ERK) and NF-κB activation. Conclusions. Cordycepin is a potent inhibitor of IL-1β-induced chemokine production and MMP expression and strongly blocks the p38/JNK/ AP-1 signalling pathway in RASFs.