Analyses of Extracellular ATP Present in GCF of the Patients with Periodontitis

Nova Southeastern University, Davie, Florida, USA

Objective: Endogenously released damage-associated molecular patterns (DAMPs) can initiate sterile inflammatory response. As one of DAMPs, extracellular adenosine triphosphate (exATP) is released from damaged cells and elicits inflammatory responses. However, in the context of periodontitis, the expression and role of exATP remain unclear. The purpose of this study was to monitor the levels of exATP in gingival crevice fluid (GCF) isolated from patients with periodontitis, and to determine the effects exATP on productions of IL-1β from epithelial cells and lymphocytes in vitro. Methods: GCF was collected from healthy and diseased sites of patients with periodontitis (n=10) to investigate the levels of exATP and IL-1β using bioluminescence ATP assay and ELISA, respectively. Monocytes and neutrophils that were freshly isolated from peripheral blood of healthy subjects and gingival epithelial cell line (OBA9) were stimulated in vitro with E. coli LPS or BzATP (modified ATP with extended half-life) to evaluate the productions of exATP and IL-1β. Results: The levels of exATP and IL-1β in the GCF collected from diseased site were significantly higher than those detected in healthy sites (Pin vitro stimulation with LPS, monocytes, neutrophils and epithelial cells released exATP. BzATP induced the production of IL-1β from monocytes and neutrophils, but not epithelial cells. Conclusion: Results suggest that ATP may represent a novel proinflammatory biomarker. Further studies are required to evaluate the pathophysiological role of ATP in periodontitis, which may lead to the development of a novel anti-inflammatory approach for periodontitis.