Signal transduction pathways involved in the synergistic stimulation of prostaglandin production by interleukin-1beta and tumor necrosis factor alpha in human gingival fibroblasts.
J Dent Res 1999;
78:61-8. [PMID:
10065947 DOI:
10.1177/00220345990780010901]
[Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Accumulating evidence indicates that prostaglandins play an important role in the pathogenesis of periodontal disease. In this study, the effects and interactions between IL-1beta and TNFalpha on prostaglandin production and its regulation were investigated. The cytokines IL-1beta and TNFalpha stimulated prostaglandin E2 (PGE2) and prostacyclin (PGI2) production in gingival fibroblasts. Simultaneous treatment of the cells with IL-1beta and TNFalpha resulted in a synergistic stimulation of PGE2 and PGI2 formation. IL-1beta and, to a lesser extent, TNFalpha stimulated the release of 3H-arachidonic acid (3H-AA), and simultaneous addition of IL-1beta and TNFalpha further increased the release of 3H-AA from pre-labeled gingival fibroblasts. Furthermore, IL-1beta and, to a lesser extent, TNFalpha induced the expression of cyclooxygenase-2 (COX-2) mRNA. Simultaneous addition of IL-1beta and TNFalpha synergistically enhanced COX-2 mRNA levels, accompanied by a corresponding stimulation of PGE2 synthesis. Neither IL-1beta, TNFalpha, nor the combination of these two cytokines affected COX-1 mRNA levels. PMA, known to activate protein kinase C (PKC), enhanced the stimulatory effect of IL-1beta, TNFalpha, and the combination on COX-2 mRNA levels accompanied by a corresponding increase in PGE2 production. The phospholipase A2 (PLA2) inhibitor, BPB, and the PKC inhibitor, BIS, reduced PGE2 production, whereas dexamethasone, indomethacin, and NS-398 completely abolished PGE2 production induced by IL-1beta, TNFalpha, and the combination. The study indicates that the synergistic stimulation of prostaglandin production by IL-1beta, and TNFalpha is mediated partly at the level of COX-2 and partly at the level of PLA2 and that PKC is involved in the signal transduction of the synergy between the two cytokines. The synergy between IL-1beta and TNFalpha may play an important role in the inflammatory processes in gingival tissue in vivo.
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