Subpopulations of marrow stromal cells share a variety of osteoblastic markers.

A series of stromal cell lines derived from mouse bone marrow, representing subpopulations of putative stromal cell types, were examined for the expression of osteoblastic properties. The effects of dexamethasone and specific inhibitors on alkaline phosphatase activity, cAMP response to bone-seeking hormones, and the ability to mineralize extracellular matrix in vitro as well as collagen typing were used as osteoblastic markers. We found that all stromal cell types examined possess some osteoblastic features but differ in the degree of expression. The data provide support to the hypothesis of a common stem cell for marrow stromal cells.