Human dental pulp stem cells express many pluripotency regulators and differentiate into neuronal cells

Stem cells were isolated from human dental pulp using an optimized method, in which pulp pieces were digested by enzymes and immobilized to enhance cell outgrowth. Stem cell marker expression was detected by reverse transcription-PCR (RT-PCR), and differentiation markers were detected by real-time quantitative RT-PCR and immunocytochemistry. Results showed that dental pulp stem cells actively expressed nanog, oct4, nucleostemin slain-1, jmjd1a, jmjd2c, and cyclin D1. When stem cells were induced to differentiate into neurons, nucleostemin, nanog, and cyclin D1 expres-sion significantly decreased, whereas expression of neuronal markers, such as microtubule asso-ciated protein-2 and neurofilament-heavy, significantly increased. These results suggested that stem cells exited a pluripotent state and entered a neuronal differentiation pathway. In addition, results demonstrated that human dental pulp serves as a reservoir of stem cells that express defined stem cell markers; these cells were easily isolated and were induced to differentiate towards a desired cell lineage.