Expression of OPG and RANKL at protein level in human periodontal ligament cells and the effect of 1alpha,25(OH)(2) vitamin D(3) on the secretion of OPG protein in vitro.

Abstract

OBJECTIVE: To study the expression of osteoprotegerin(OPG) and receptor activator nuclear factor kappa B ligand(RANKL) at protein level in human periodontal ligament cells (HPDLCs), and the effect of 1alpha,25(OH)(2) vitamin D(3) [1,25(OH)(2)vitD(3)] on the secretion of OPG protein in vitro. METHODS: HPDLCs were harvested in vitro by sequential digestion with trypsin and collagenase. The expression of RANKL in HPDLCs at protein level was tested by immunocyto-chemistry. Enzyme-linked immunoadsordent assay (ELISA) was used to detect the OPG protein which was secreted into the culture medium by HPDLCs cultured with and without 10(-8) mol/L 1alpha,25 (OH)(2)vitD(3) on the 0, 2nd, 4th, and 6th days, respectively. RESULTS: RANKL protein was detected on the membrane and plasma of HPDLCs, and OPG protein was secreted in the culture medium. The secretion of OPG protein was down-regulated by 10(-8) mol/L 1alpha,25 (OH)(2)vitD(3). CONCLUSION: HPDLCs have the bone metabolism system of OPG/RANKL, which works during the process of 1alpha,25 (OH)(2)vitD(3) inducing HPDLCs. The conclusion has laid the groundwork for the study on bone remodelling mechanisms of HPDLCs.