Cyclooxygenase-2 Inhibitors Decrease Interleukin-1β-Stimulated Prostaglandin E₂ and IL-6 Production by Human Gingival...

Area of Science:

• Periodontology
• Inflammation Research
• Fibroblast Biology

Background:

• Gingival fibroblasts in periodontitis produce IL-6, a key cytokine in bone resorption.
• Prostaglandin E2 (PGE2) regulates IL-6 production, and non-steroidal anti-inflammatory drugs (NSAIDs) target cyclooxygenase (COX) enzymes.
• The role of COX-2 in IL-1β-stimulated IL-6 and PGE2 production by aggressive periodontitis fibroblasts is not well understood.

Purpose of the Study:

• To investigate the effect of COX inhibitors on PGE2 and IL-6 production by IL-1β-stimulated gingival fibroblasts from patients with severe periodontitis.
• To determine if selective COX-2 inhibition impacts IL-6 production in this cellular model.

Main Methods:

• Gingival fibroblasts from healthy and severe periodontitis patients were cultured with or without IL-1β.
• Cells were treated with indomethacin (COX-1/2 inhibitor) or selective COX-2 inhibitors (NS-398, celecoxib, rofecoxib).
• PGE2 and IL-6 levels in culture supernatants were quantified using ELISA.

Main Results:

• All COX inhibitors significantly reduced IL-1β-stimulated PGE2 production in a dose-dependent manner (>90% reduction).
• Selective COX-2 inhibitors, but not indomethacin, partially reduced IL-1β-stimulated IL-6 production (up to ~60%) in a dose-dependent manner.
• Adding exogenous PGE2 with COX-2 inhibitors restored IL-6 levels, indicating PGE2's role in IL-6 regulation.

Conclusions:

• COX-2 inhibition effectively reduces PGE2 production in IL-1β-stimulated periodontitis fibroblasts.
• Selective COX-2 inhibition partially reduces IL-6 production, mediated by PGE2.
• Targeting COX-2 may offer a therapeutic strategy for managing fibroblast-derived IL-6 in severe periodontitis.