To characterize the transcriptional and posttranscriptional regulation of collagenase-1 by adenosine receptor stimulation in interleukin-1 (IL-1)stimulated fibroblast-like synoviocytes (FLS).
Methods. FLS were stimulated with IL-1 and either the nonselective adenosine agonist 5'-Nethylcarboxamidoadenosine (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 collagenasechloramphenicol 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 mFWA half-life showed that both NECA and forskolin decreased the half-life of collagenase mFWA in IL-l-stimulated FLS and HS68 cells.
Conclusion. The findings of this study demonstrate that NECA and forskolin decrease collagenase