ABSTRACT
BACKGROUND: Runx2 plays a central role in osteogenic differentiation, which is of important significance in new bone formation.OBJECTIVE: To observe the effect of Runx2 over-expression on osteogenic differentiation of human umbilical cordblood mesenchymal stem cells.METHODS: Runx2 was generated by RT-PCR and the recombinant adenovirus (pAd-Runx2) was constructed. The viraltiter was determined by air dilution method. After being transfected into human umbilical cord blood mesenchymal stemcells, the green fluorescence was observed under fluorescence microscope. Real-time fluorescent quantitative PCR andwestern blot were used to detect mRNA expression changes of osteogenesis related genes, Runx2, OCN, BMP-2, ALP,in human umbilical cord blood mesenchymal stem cells at 1, 3, 7 and 14 days after transfection.RESULTS AND CONCLUSION: The recombinant adenovirus was successfully constructed and the titer was1.7×1010 pfu/L. After infection by pAd-Runx2, human umbilical cord blood mesenchymal stem cells expressed greenfluorescence protein clearly under the fluorescence microscope. Cells in the transfected group differentiated intoosteoblast-like cells, and those in the control group stayed the same as pre-infected. The expression of Runx2, OCN,BMP-2 and ALP in the transfected group increased over time to some extent, but these changes were not detected in thecontrol group. These findings indicate that Runx2 over-expression can promote the osteogenic differentiation of humanumbilical cord blood mesenchymal stem cells.