Characteristic expression of MSX1, MSX2, TBX2 and ENTPD1 in dental pulp cells

Dental pulp cells (DPCs) are a promising source of transplantable cells in regenerative medicine. However, DPCs have not been fully characterized at the molecular level. The aim of the present study was to distinguish DPCs from various source-derived mesenchymal stem cells (MSCs), fibroblasts (FBs) and other cells by the expression of several DPC-characteristic genes. DPCs were isolated from human pulp tissues by the explant method or the enzyme digestion method, and maintained with media containing 10% serum or 7.5% platelet-rich plasma. RNA was isolated from the cells and from dental pulp tissue specimens. The mRNA levels were determined by DNA microarray and quantitative polymerase chain reaction analyses. The msh homeobox 1, msh homeobox 2, T-box 2 and ectonucleoside triphosphate diphosphohydrolase 1 mRNA levels in DPCs were higher than that of the levels identified in the following cell types: MSCs derived from bone marrow, synovium and adipose tissue; and in cells such as FBs, osteoblasts, adipocytes and chondrocytes. The enhanced expression in DPCs was consistently observed irrespective of donor age, tooth type and culture medium. In addition, these genes were expressed at high levels in dental pulp tissue in vivo. In conclusion, this gene set may be useful in the identification and characterization of DPCs in basic studies and pulp cell-based regeneration therapy.