Osteogenic and adipogenic cell fractions isolated from postnatal mouse calvaria.

The use of stem/progenitor cells represents a promising approach to treat craniofacial bone defects, but successful treatments will rely on the availability of cells that can be expanded in vitro and which will differentiate appropriately in vivo. The calvaria may represent a source of autologous cells for such purposes. We demonstrate expression of stem cell antigen-1 (Sca-1) in mouse calvaria. We isolated Sca-1(+) and Sca-1(-) cells at high purity and tested the ability of these cells to differentiate into adipose and bone. We show that the Sca-1(+) cell fraction has adipogenic differentiation potential and that the cell Sca-1(-) fraction has osteogenic differentiation potential. The Sca-1(+) cell fraction partially retains its adipogenic differentiation potential and the Sca-1(-) cell fraction partially retains its osteogenic differentiation potential after in vitro expansion. These data suggest that the calvaria may be used as a source of stem/progenitor cells that can be expanded in vitro and transplanted in vivo for craniofacial tissue regeneration.