Co-stimulation of 1,25(OH)₂D₃ and BMP-2 Enhances the Expression of VDR in Osteoblast-Like MC3T3-E1 Cells

Abstract

1,25(OH)₂D₃ appears to indirectly induce osteoclast formation by up-regulating RANKL expression in marrow stromal cells.A recent study has shown that BMP-2 enhances the induction of osteoclast formation by 1,25(OH)₂D₃,but little is known about the mechanism of the promoting effect of 1,25(OH)2D3 and BMP-2 co-stimulation on osteoblast-osteoclast interaction. In this study,we investigated the time-dependent expression of RANKL and VDR in osteoblasts co-stimulated with 1,25(OH)₂D₃ and BMP-2.The mRNA expression of RANKL in Osteoblast-Like MC3T3-E1 Cells increased significantly after co-stimulation with 1,25(OH)₂D₃ and BMP-2 compared with that stimulated with 1,25(OH)₂D₃ only.VDR expression also increased significantly after co-stimulation.These results suggested that BMP-2 may accelerate the 1,25(OH)₂D₃ –induced osteoclast formation by through enhance the expression of VDR and following RANKL in osteoblast.