OBJECTIVETo investigate the effect of adenovirus expressing human bone morphogenetic protein-7 (hBMP-7) on proliferation and differentiation of human dental pulp cells.

METHODSThe replication-deficient adenoviral vector encoding hBMP-7 gene was constructed by using homologous recombinant modality. The efficiency of transfection was evaluated by fluorescent microscopy and flow cytometry. The expression of hBMP-7 protein in adenovirus-infected dental pulp cells was determined by Western blot. The proliferation of cells was tested by MTT method, the activity of alkaline phosphatase was assayed, von Kossa staining was used to detect mineralized nodule formation, and the expression of DSPPmRNA in cells was detected using semi-quantitative RT-PCR.

RESULTSGreen fluorescent protein was visible under fluorescent microscopy. Higher transfection efficiency (91.1 +/- 1.0)% could be obtained at MOI of 75. Western blot from dental pulp cells infected with Ad-hBMP-7 for 48h detected protein expression of a hBMP-7 gene. The activity of alkaline phosphatase in cells was significantly higher than those of the control groups (P < 0.05). The cells infected with Ad-hBMP-7 had the ability of mineralization. DSPP mRNA expression of cells was in a time- and dose- dependent manner.

CONCLUSIONSAd-hBMP-7 can induce human pulp cells into odontoblasts, but has no obvious effect on their proliferation.