Effect of Prevotella Nigrescens Lipopolysaccharide on Osteoclastogenesis-related Cytokine Secretion

Purpose: Lipopolysaccharide (LPS) is a bacterial cell component that plays multifunctional roles on inflammatory reactions. LPS from various periodontal pathogens is supposed to be a major virulence factor of periodontal disease. In the present study, we investigated the effects of Prevotella nigrescens lipopolysacharide (Pn-LPS) on inducing osteoprotegrin (OPG), macrophage colony-stimulating factor(M-CSF), tumor necrosis factor alpha (TNF-a), transforming growth factor beta (TGF-b) and prostaglandin E2 (PGE2), in order to understand mechanism of LPS-induced osteoclastogenesis . Methods: Pn-LPS was prepared by Yi & Hackett (2000) method. Various concentration Pn-LPS and E. coli LPS (0, 0.1, 1ug/ml) treated in osteoblast single culture and co-culture system by using mouse calvarial osteoblast and bone marrow cells. Culture supernatants were collected at 3, 6, and 9days. Each cytokines concentration was measured enzyme-linked immunosorbent assay (ELISA). Result: Cultured with various concentration of Pn-LPS for 3, 6, and 9days, OPG production decreased in a time and dose-dependent manner. However, PGE2 production increased in a dose-dependent manner. In osteoblast single culture, M-CSF production increased in a time-dependent manner, but in co-culture system decreased in a time-dependent manner. In co-culture system, TNF-a production increased in a concentration-dependent manner at 3days and TGF-b increased 1ug/ml of Pn-LPS for 9days. Conclusion: These results suggest that osteoclastogenesis induced by Pn-LPS was probably associsted with the decrease of OPG and the increase of TNF- a and PGE2.