Isolation and characterization of SSEA-4-positive subpopulation of human deciduous dental pulp cells

Objectives: It is well accepted that stage-specific embryonic antigen (SSEA)-4 is an antigen that is useful to isolate adult stem cells analogous to embryonic stem cells. Therefore, in the present study, we investigated whether SSEA-4 can also be used as a marker to identify human deciduous dental pulp (D-DP) stem cells. Materials and methods: Intact deciduous teeth were collected from healthy patients who were undergoing orthodontic treatment at Okayama University Hospital. Immunofluorescence analysis, flow cytometric analysis, and multilineage differentiation assay were performed to characterize SSEA-4+ D-DP cells. Results: The D-DP cells had the characteristics of mesenchymal stem cells (MSCs), namely plastic adherence, specific surface antigen expression, and multipotent differentiation potential. SSEA-4 expression was detected in D-DP cells in vitro and ex vivo samples. A flow cytometric analysis demonstrated that 21.2 % of the D-DP cells were positive for SSEA-4. The SSEA-4+ clonal D-DP cells showed multilineage differentiation potential toward adipocytes, osteoblasts, and chondrocytes in vitro. In fact, 26.1 % (6/23) of the SSEA-4+ clonal D-DP cells showed adipogenic potential, 91.3 % (21/23) showed osteogenic potential, 91.3 % (21/23) showed chondrogenic potential, and 87.0 % (20/23) showed both osteogenic and chondrogenic potential. Conclusions: Thus, the majority of SSEA-4+ D-DP cells had the potential for multilineage differentiation. Hence, SSEA-4 appears to be a specific marker that can be used to identify D-DP stem cells. Clinical relevance: SSEA-4+ D-DP cells appear to be a promising source of stem cells for regenerative therapy.