Regulation of osteoprotegerin and receptor activator of nuclear factor-k B ligand in human dental follicle cells

Purpose: To determine the regulation of the expression of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand in human dental follicle cells by colony-stimulating factor-1, parathyroid hormone-related protein and bone morphogenetic protein-2. Materials and Methods: Primary human dental follicle cells were cultured. The fifth passaged human dental follicle cells were separately cocultured with colony-stimulating factor-1 (25 ng/mL) parathyroid hormonerelated protein (10 ng/mL) and bone morphogenetic protein-2 (100 ng/mL) for 0.5, 1, 3, 6, 12, and 18 hours. Using enzyme-linked immunosorbent assays and reverse transcription polymerase chain, the expression of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand were examined. Results: The results of enzyme-linked immunosorbent assays and reverse transcription polymerase chain revealed that colony-stimulating factor-1 and parathyroid hormone-related protein decrease the secretion of osteoprotegerin significantly after incubation for 1 hour (p<0.01). Conversely, the expression of receptor activator of nuclear factor-kappa B ligand increased significantly after incubation with colony-stimulating factor-1 and parathyroid hormone-related protein separately for 3 hours (p<0.01). While bone morphogenetic protein-2 regulates them in the contrary. Conclusion: At defined concentration, colony-stimulating factor-1 and parathyroid hormone-related protein decrease osteoprotegerin secretion of human dental follicle cells and increase the expression of receptor activator of nuclear factor-kappa B ligand. Thus, a reduction in secretion of the osteoprotegerin protein and an increase in the expression of receptor activator of nuclear factor-kappa B ligand at defined times may promote the osteoclastogenesis needed for eruption, but enhancement of osteoprotegerin and decrease of receptor activator of nuclear factor-kappa B ligand may promote alveolar bone formation. (Int Chin J Dent 2006; 6: 97-104.)