Characterization of Human Mobilized Dental Pulp Stem Cells (MDPSCs) From the Pulp of Immature Third Molar Tooth Compared to Colony-derived Dental Pulp Stem Cells (DPSCs)

Objectives: Dental pulp tissue is an attractive source of mesenchymal stem cells (MSCs). We have previously isolated mobilized dental pulp stem cells (MDPSCs) using granulocyte-colony stimulating factor (G-CSF) from mature discarded teeth for clinical use. MDPSCs have higher migration potential and higher expression of angiogenic/neurotrophic factors compared with colony-derived DPSCs. And greater effects of MDPSCs on angiogenesis/vasculogenesis and pulp regeneration have also been demonstrated in an ectopic tooth root transplantation model. Another previous report demonstrated that there is little difference in the regeneration potential of MDPSCs between young and aged donors with mature teeth. Immature teeth having large volume of pulp tissue can be more optimal source for isolation of MDPSCs with the possibility to increase the number of isolated cells. Thus, this study was performed to evaluate utility of the isolation method employing G-CSF-induced mobilization for human immature teeth.
Methods: Colony-derived DPSCs were isolated from third molar immature teeth with open apex. MDPSCs were further isolated from the DPSCs by the previous method. At the 6th passage of culture, the stem cell properties of MDPSCs were compared to those of DPSCs by flow cytometry, a horizontal chemotaxis assay, real-time RT-PCR analysis of mRNA expression of angiogenic/neurotrophic factors and induced differentiation assays. In addition, the trophic effect of the secretome on migration, anti-apoptosis and neurite extension was examined. Regeneration potential of the MDPSCs were further compared to the DPSCs in mouse ischemic hindlimb model and ectopic tooth transplantation model.
Results: MDPSCs had higher positive rate of CXCR4 and G-CSFR, higher migration ability and higher expression of angiogenic/neurotrophic factors compared to DPSCs. Secretome of MDPSCs displayed higher stimulatory effect on migration and endothelial differentiation. In addition, higher vascularization and pulp regeneration potentials were observed in MDPSCs compared to DPSCs.
Conclusions: The isolation method employing G-CSF-induced mobilization is also useful for immature teeth.