In vitro induction of osteogenic differentiation from non-osteogenic mesenchymal cells.

The process of ectopic bone formation suggests that extraskeletal cells are capable of osteogenesis. Alkaline phosphatase (ALP) activity is considered to be an early marker of osteogenic differentiation. This study determined whether cells from the rabbit dermis, striated muscle and extramedullary adipose tissue could undergo osteogenic differentiation in vitro. The cells were cultured with two osteoregulators, recombinant human bone morphogenetic protein 2 (rhBMP2) and dexamethasone. Incubation of extramedullary adipose cells with a combination of rhBMP2 and dexamethasone resulted in an increase in their ALP activity. The results suggest that extramedullary adipocytic cells may undergo osteogenic differentiation.