Bone morphogenetic protein receptor IB as a marker for enrichment of osteogenic precursor-like cells in human dermis.

The scarcity of bone marrow mesenchymal stromal cells (BMSCs) prompts the search for alternative sources for cell-based bone defects repair. Human dermal fibroblasts (FBs) have been shown to have a high proliferative potential and the capacity to differentiate into an osteogenic phenotype. The easy and repeated harvest in large quantities makes this cell source a potential candidate for bone tissue engineering. The aim of our study was to compare directly the immune phenotype, proliferative capacity and osteogenic differentiation potential of FBs with that of "gold standard" BMSCs or adipose-derived mesenchymal stromal cells (ADSCs), another alternative osteoprogenitor cell source. Flow cytometry demonstrated that FBs, ADSCs and BMSCs shared common cell surface marker protein expression profiles when using a panel of surface antigens. FBs had the highest proliferative potential, but lowest osteogenic differentiation potential in vitro, compared with ADSCs or BMSCs. More importantly, BMPR-IB(+)-sorted FBs subpopulation had a higher osteogenic differentiation potential than BMPR-IB(-)-sorted FBs subpopulation. Our results indicated that the heterogeneous FBs were not an appropriate cell source for bone tissue engineering. Immunoselection by BMPR-IB can generate highly purified osteogenic precursor-like cells in the human dermis.