Posttranscriptional regulation of collagenase-1 gene expression in synoviocytes by adenosine receptor stimulation

Objective. To characterize the transcriptional and posttranscriptional regulation of collagenase-1 by adenosine receptor stimulation in interleukin-l (IL-1)-stimulated fibroblast-like synoviocytes (FLS). Methods. FLS were stimulated with IL-I and either the nonselective adenosine agonist 5'-N-ethylcarboxamidoadenosine (NECA) or the adenylate cyclase activator forskolin, Electrophoretic mobility shift assays were performed to determine AP-1 and cAMP-responsive element binding protein (CREB) activation, Transcriptional activation was-determined by transfecting HS68 dermal fibroblasts with a collagenase-chloramphenicol acetyltransferase construct, Finally, collagenase messenger RNA (mRNA) half-life was determined by activating cells in the presence of IL-1, IL-1 + NECA, or IL-1 + forskolin and culturing cells in the presence of actinomycin D. Results. NECA and forskolin had no effect on AP-1 activation, c-jun or c-fos gene expression, or CREB phosphorylation, IL-1 markedly increased collagenase promoter activity, and neither NECA nor forskolin blocked this action, Studies of mRNA half-life showed that both NECA and forskolin decreased the half-life of collagenase mRNA in IL-l-stimulated FLS and HS68 cells. Conclusion. The findings of this study demonstrate that NECA and forskolin decrease collagenase gene expression in FLS and dermal fibroblasts due to enhanced mRNA degradation.