Prostaglandin E2 potentiates interleukin-1β induced interleukin-6 production by human gingival fibroblasts

Abstract Increased levels of cytokines and prostanoids have been detected in inflamed gingival tissue and may play an important role in periodontal pathogenesis. Recent studies suggest that monocytic products, such as interleukin (IL)-1β, could stimulate IL-6 production by human gingival fibroblasts (HGF). In this context, the production of local cytokines and inflammatory mediators could regulate the secretory capacity of resident gingival fibroblasts. Therefore, the purpose of this study was to determine if PGE₂ induced by IL-1β could potentiate the IL-6 response by HGF. Utilizing an ELISA, it was determined that maximal IL-6 occurred when HGF were stimulated with 0.10–10 nM IL-1β. These concentrations of IL-1β also induced a small, but significant increase in PGE₂ production by HGF. Interestingly, the combination of ILγβ and PGE₂ induced a synergistic rise in IL-6 production by HGF. Moreover, inclusion of indomethacin caused a 20% reduction in IL-6 production and totally eliminated PGE₂ production. These findings provide additional rationale for the clinical use of NSAIDs in the management of periodontal disease due to their ability to attenuate production of both PGE₂, and IL-6. These results suggest the endogenous PGE₂ induced by IL-1β plays an important regulatory role in IL 6 production by HGF. Moreover, they support the concept that elevated PGE₂ induced during inflammation can regulate HGF secretory function.