Human ES Cell-Derived Mesenchymal Cells Express Dental Pulp Cell Markers

Objectives: While Human Embryonic Stem Cells (hESCs) hold great potential as a source of cells for regenerative therapies of the oral and maxillofacial complex, it is unclear how to direct these pluripotent cells to oral tissue fates. Recently, we have derived mesenchymal progenitor cell lines (MPCs) from hESCs (H9 cell line) that differentiate into bone and fat. However, the potential of these cells to differentiate into dentin-producing cells remains unknown. Our goal was to characterize the phenotype of three, hESC-derived MPCs as a first step towards elucidating the potential of MPCs to differentiate into dentin-producing lineages. Methods: Three distinct MPC cell lines were derived from hESCs (H9-MSC, H1-MSC, and EDK) by sequentially growing cells on mouse embryonic fibroblasts and Type I collagen-coated plates (EDK1), or by expanding FACS-sorted, CD73+ cells (H9- and H1-MSC). Cultured human dental pulp stem cells (hDPSCs) isolated from extracted wisdom teeth were used as controls. MPCs were compared to DPSCs using FACS analysis for surface markers including CD117, CD146, CD34, CD105, CD31, CD45, CD34 and STRO-1. FACS-sorted populations of STRO-1 positive cells from DPSCs and H1-MSC and H9-MSC cells were expanded for further analysis. Results: FACS analysis revealed that cell surface markers CD-105 and CD-146 were found in DPSCs, H1-MSC and H9-MSC but not in EDK cells, which demonstrated properties of mature fibroblasts. STRO-1 was found in DPSCs and in all MPCs tested. Conclusions: Overlapping surface marker expression between DPSCs and specific MSC lines suggests that the differentiation potential of human DPSC and MPC may be similar. Future studies are needed to asses the biological potential for dentin production by these hESC-derived cells, and to establish if they can be used as a source of dental mesenchymal cell-derived tissue regeneration for applications in endodontics and restorative dentistry. Supported by NIH/NIDCR Grants DE017413 (JAG) and DE016132 (PCY).