Haiyan Sun, DDS, PhD,(a) Yongkuan Zhang, DDS, PhD,(a) Zuolin Jin, DDS, PhD, and Zhu Li, DDS, PhD (a)Equally contributed to the manuscript
Department of Orthodontics, College of Stomatology, The Fourth Military Medical University, Xi’an,
P. R. China
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 hormone- related 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.)
Key Words: colony-stimulating factor-1, dental follicle, osteoprotegerin, parathyroid hormone, tooth eruption.