Isolation and characterization of human dental tissue-derived stem cells in the impacted wisdom teeth: comparison of dental follicle, dental pulp, and root apical papilla-derived cells

Abstract

Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP) , and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of trans cription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco' s modified Eagle' s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) a nd cell surface mark- ers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sortin g (FACS) analy- sis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immuno- histochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. Afte r passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell marker s were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most l arge in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesen chy- mal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) h ave much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.