Expressing osteogenic growth peptide in the rabbit bone mesenchymal stem cells increased alkaline phosphatase...

The multipotent mesenchymal stem cells (MSCs) were distributed in the bone marrow stroma, and could generate all of the different skeletal cell lineages. The osteogenic differentiation of MSCs, which is indicated by the increased alkaline phosphatase (ALP) activity and the enhanced accumulation of collagen, could be induced by a tetradecapeptide termed osteogenic growth peptide (OGP). It has been hypothesized that the OGP induces the osteogenic differentiation of MSCs probably through regulating the fibroblast growth factor signaling pathways. Although the chemically synthesized OGP was widely applied to study the osteogenic differentiation of MSCs, transferring and expressing OGP gene in target cells is more desirable, especially for gene therapy, given the advantages and convenience on the stable expression of OGP.

In this study, we attempt to test the effect of OGP gene transfection; we constructed a eukaryotic expression vector, pcDNA3.1-OGP, which contained the OGP-coding DNA fragment. Subsequently, the vector was transfected into the rabbit MSCs.

A significant increase of ALP activity was detected in the supernatant of pcDNA3.1-OGP transfected MSCs, and the enhanced collagen accumulation, which was inferred by the increased hydroxyproline content and RT-PCR.

These results implied that transfecting the OGP-expressing vectors into MSCs might induce the osteogenic differentiation of MSCs.