Methods: Cell cultures were isolated from deciduous tooth and third molar pulp and were grown in DMEM supplemented with 10 % FBS. Cells between 3-5 passages, grown in serum-free medium were characterized for a panel of stem cell markers by RT-PCR, immunocytochemistry and flow-cytometry. CD117+ cells were magnetically separated and subjected to pancreatic differentiation protocol. Expression of a panel of pancreatically related transcription factors were tested with RT-PCR. Immunocytochemistry and flow-cytometry of insulin, glucagon, somatostatin, pancreatic polypeptide, GLUT2 and pancreatic amylase was also carried out after differentiation. During the differentiation the cultures were exposed to 1ng/mL air of hydrogen sulfide.
Results: Both mesenchymal stem cell cultures were proven to express pluripotent cell markers prior to differentiation. PDX1, Pax6, MNX, NEUROG1, Nkx6-1 and HHEX were found expressed in different levels after differentiation. Expression of insulin, glucagon, somatostatin and pancreatic polypeptide, GLUT2 and the exocrine marker pancreatic amylase were also found positive by immunocytochemistry and flow-cytometry. Hydrogen sulfide increased the differentiation of alpha cells compared with control.
Conclusions: The present results demonstrate the ability of CD117+ fraction of both cell cultures to differentiate to endodermal type. These cells also acquired characteristics of pancreatic endocrine and exocrine cells, and hydrogen sulfide increases the differentiation of some kinds of pancreatic cells. Human dental pulp cells may therefore have great potential for future cell therapy of diabetic patients.