Mesenchymal stem cells have the ability to differentiate into insulin-producing cells, raising the hope for diabetes mellitus treatment. The aim of this research was to study the ability of stem cells from discarded natal teeth to differentiate into insulinproducing cells. Two vital human natal teeth were obtained from a healthy 2-day-old female. Stem cells from the dental pulp were isolated, cultured under xenogenic-free conditions, propagated and characterized. Proliferative activity, population doubling time and viability were measured, and the multipotent differentiation ability was investigated. A twostep protocol was used to induce the human natal dental pulp stem cells to differentiate into insulinproducing cells. Phenotypic analysis was done using flow cytometry. Immunohistochemistry was performed to detect insulin and C-peptide. PDX1, HES1 and Glut2 gene expression analysis was performed by quantitative reverse transcription-polymerase chain reaction. Human natal dental pulp stem cells were able to undergo osteogenic, chondrogenic and adipogenic differentiation upon exposure to the specific differentiation media for each lineage. Their differentiation into insulin-producing cells was confirmed by expression of C-peptide and insulin, as well as by 975.4 % higher expression of PDX-1 and 469.5 % higher expression of HES1 in comparison to the cells cultivated in standard cultivation media. Glut2 transporter mRNA was absent in the non-differentiated cells, and differentiation of the stem cells into insulin-producing cells induced appearance of the mRNA of this transporter. We were the first to demonstrate that stem cells obtained from the pulp of natal teeth could be differentiated into insulinproducing cells, which might prove useful in the stem cell therapy for type 1 diabetes.

Department of Dentistry Charles University Faculty of Medicine in Hradec Králové Hradec Králové Czech Republic

Department of Histology and Embryology Charles University Faculty of Medicine in Hradec Králové Hradec Králové Czech Republic

Department of Surgery and Oral Medicine Oro dental division National Research Centre Cairo Egypt