Effects of core binding factor α1 or bone morphogenic protein‐2 overexpression on osteoblast/cementoblast‐related gene expressions in NIH3T3 mouse cells and dental follicle cells

Abstract

Bone morphogenic protein-2 (BMP-2) has long been used to promote bone and periodontal regeneration, while core binding factor alpha1 (CBFA1) plays important roles in both osteogenic differentiation and tooth morphogenesis. The aim of this study was to evaluate the effects of CBFA1 or BMP-2 overexpression on osteoblast/cementoblast-related gene expressions in NIH3T3 cells and dental follicle cells (DFCs). CBFA1 or BMP-2 overexpression in NIH3T3 and DFCs was achieved by infection with retroviral vectors containing CBFA1 or BMP-2 cDNA. Cells stably integrated with CBFA1 or BMP-2 cDNA were selected with G418 for 14 days. Western blotting, real-time reverse transcriptase-polymerase chain reaction, and in vitro mineralization assay were performed to evaluate effects of CBFA1 or BMP-2 overexpression in cells undergoing osteoblast/cementoblast differentiation. Our results demonstrated that osteoblast/cementoblast-related gene expression levels in CBFA1-overexpressing NIH3T3 cells were higher than those in BMP-2-overexpressing cells. More mineral nodules were observed in CBFA1-overexpressing NIH3T3 cells than in BMP-2-overexpressing cells. CBFA1 overexpression in DFCs also increased osteoblast/cementoblast-related gene expression and promoted mineral nodule formation. However, no significant changes in gene expression levels nor mineral nodule formation were found in BMP-2-overexpressing DFCs when compared with empty vector transduced DFCs. CBFA1 overexpression up-regulated expression levels of osteoblast/cementoblast-related genes and enhanced in vitro osteogenic differentiation more efficiently than BMP-2 in both NIH3T3 cells and DFCs.