Human dental pulp stem cells as a potential feeder layer for human embryonic stem cell culture

Background: Human embryonic stem (hES) cells are pluripotent, and can differentiate into three germ layers. Traditionally, cultures of hES cells are maintained in a system, containing mouse embryonic fibroblasts as a feeder layer for support of undifferentiated growth. However, contamination by animal cells limits the use of hES cells. Objective: We evaluated the use of human dental pulp stem cells (hDPSCs) as a feeder layer for hES cell culture. It should be possible to obtain a new source of human mesenchymal stem cells for feeder cells to maintain undifferentiated growth of hES cells. Methods: hDPSCs from removed impacted wisdom teeth (third molars) were extracted, cultured, and characterized for mesenchymal stem cell properties. Furthermore, hDPSCs were used as a feeder layer for culturing Chula2 and Chula5 hES cell lines. Finally, hES cell lines grown on hDPSCs feeders were examined embryonic stem cell properties. Results: We found that hDPSCs, which have mesenchymal properties, can support undifferentiated growth of hES cell lines. After prolonged culture (passage 17), these hES cell lines still maintain ES cell properties including typical morphology seen in hES cells, the expression of pluripotency markers (Oct4, Sox2, Nanog, Rexl, SSEA-3, SSEA-4, TRA-1-60, and TRA-1-81), embryoid body formation and retention of a normal karyotype. Conclusion: hDPSCs, derived from the pulp tissue of impacted third molars, are a potential source of human feeder cells for the culture of undifferentiated hES cells.