[Expression of cell surface antigens during the differentiation of osteoblast by human bone marrow-derived...

To explore the phenotypic changes of some cell surface antigens in the process that the bone marrow-derived mesenchymal stem cells (MSCs) differentiate into osteoblast lineage under certain conditions.

The mononuclear cells were isolated from human bone marrow and cultured in the medium in the presence (experimental group) or absence (control group 1) of dexamethasone, ascorbic acid and beta-glycerophosphate, or in the alpha-MEM only (control group 2). The expressions of CD45, CD34, CD117, CD90, and HLA-DR were examined by flow cytometry on culture day 7, 12, and 17.

Human bone marrow MSCs can differentiate into mature cells with the characteristics of osteoblasts in vitro. The expression of CD45 was low in the experimental group and in the control groups on culture day 7, and became negative from day 12 in all groups. The expressions of CD34 and CD117 were negative at all time points. The expression of CD90 increased on day 12 in all groups, and was more obvious in the control groups. The expression of HLA-DR was gradually elevated along with the differentiation and maturation of osteoblasts in the experimental group, but dropped in the control groups in the later time points.

MSCs can differentiate into mature osteoblasts after induction. The expression of cell surface antigens during differentiation has characteristic changes, which may be key markers in the early stage of osteoblasts differentiation.