Osteogenic growth peptide C-terminal pentapeptide [OGP(10-14)] acts on rat bone marrow mesenchymal stem cells to promote differentiation to osteoblasts and to inhibit differentiation to adipocytes.

Cumulative evidence indicates that bone marrow mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating to osteogenic and adipogenic lineages when stimulated under appropriate conditions. Whether OGP(10-14) directly regulates the progenitor cells differentiating into osteoblasts or adipocytes remains unknown. In the present study, we investigated the roles of OGP(10-14) in differentiation along these separate lineages using rat bone marrow MSCs. Our results showed that OGP(10-14) promoted osteogenic differentiation of the stem cells and concurrently inhibited adipocyte formation. OGP(10-14) increased alkaline phosphatase (ALP) activity and mineralized nodule formation, and stimulated osteoblast-specific mRNA expression of core-binding factor 1 (cbfa1). In contrast, OGP(10-14) decreased adipocyte numbers and inhibited adipocyte-specific mRNA expression of peroxisome proliferator-activated receptor-gamma 2 (PPARgamma2). These observations suggest that commitment of MSCs into osteogenic or adipogenic lineages is regulated by OGP(10-14).