ABSTRACT
Objective To investigate the effect of adenovirus-bone morphogenic protein 9 ( Ad-BMP9 ) on osteogenic differentiation of immortalized calvarial mesenchymal progenitor cells ( iCALs ) .Methods iCALs were infected with adenoviral vectors encoding BMP-9 or green fluorescent protein ( GFP) and the early osteogenic differentiation was assessed by detecting alkaline phosphatase (ALP) activity after being cultured for 3, 5 and 7 days.14 days after infection, alizarin red S staining was performed to study the formation of osteogenic calcium nodules .The expression of osteogenic marker genes Runx2 and OCN was assessed by quantitative real-time ( RT )-PCR and Western blotting .Results Significant increases in ALP activity and in the expressions of Runx 2 and OCN were detected in BMP-9 treated iCALs compared with GFP-treated cells(P<0.05).Meanwhile, alizarin red S staining showed that more mineralized nodules were found in the BMP-9 induced group .Conclusion BMP-9 can promote the osteogenic differentiation of iCALs .