Isolation and characterization of a population of immature dental pulp stem cells expressing OCT-4 and other embryonic stem cell markers.

We report the isolation of a population of immature dental pulp stem cells (IDPSC), which express embryonic stem cell markers Oct-4, Nanog, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81 as well as several other mesenchymal stem cell markers during at least 25 passages while maintaining the normal karyotype and the rate of expansion characteristic of stem cells. The expression of these markers was maintained in subclones obtained from these cells. Moreover, in vitrothese cells can be induced to undergo uniform differentiation into smooth and skeletal muscles, neurons, cartilage, and bone under chemically defined culture conditions. After in vivo transplantation of these cells into immunocompromised mice, they showed dense engraftment in various tissues. The relative ease of recovery and the expression profiles of various markers justify further exploration of IDPSC for clinical therapy.