Abstract
Among the various sources of human autologous stem cells, stem cells isolated from dental tissues exhibit excellent properties in tissue engineering and regenerative medicine. However, the distinct potential of these odontogenic cell lines remains unclear. In this study, we analyzed DNA methylation patterns to determine whether specific differences existed among three different odontogenic cell types. Using the HumanMethylation450 Beadchip, the whole genomes of human dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), and dental follicle progenitor cells (DFPCs) were compared. Then, the osteogenic potential of these cells was evaluated both in vitro and in vivo, and the methylation levels of certain genes related to bone formation differed among the three cell lines. P values less than 0.05 were considered to indicate statistical significance. The three cell types showed highly similar DNA methylation patterns, although specific differences were identified. Gene ontology analysis revealed that one of the most significantly different gene categories was related to bone formation. Thus, expression of cell surface epitopes and osteogenic-related transcription factors as well as the bone formation capacity were compared. The results showed that compared with DFPCs and DPSCs, PDLSCs had higher transcription levels of osteogenic-related factors, a higher in vitro osteogenic potential, and an increased new bone formation capacity in vivo. In conclusion, the results of this study suggested that the differential DNA methylation profiles could be related to the osteogenic potential of these human odontogenic cell populations. Additionally, the increased osteogenic potential of PDLSCs might aid researchers or clinicians in making better choices regarding tissue regeneration and clinical therapies.