Murine calvaria-derived progenitor cells express high levels of osterix and lose their adipogenic capacity

Abstract Though the mouse is the most widely used biomedical animal model, it is difficult to isolate murine mesenchymal stem cells (MSCs) from the bone marrow because of contamination by hematopoietic cells. The murine compact bone tissue of long bones is considered a novel and reliable source of MSCs with low hematopoietic cell contamination. We investigated whether the murine compact bone of the calvaria would be a promising source of MSCs due to its low bone marrow content. We isolated cells from both long bones and the calvaria using the same method. Although they shared morphological features and surface antigens similar to those of long bone-derived MSCs, the calvaria-derived cells highly expressed the osteogenic transcription factor osterix, lost their adipogenic capacity and gained a higher osteogenic capacity. These findings suggest that the cells that migrated from the calvaria were progenitor cells rather than MSCs and that the differentiation fate of mesenchymal stem/progenitor cells existing in different murine compact bone deposits is already committed.