Background: In healthy dentin conditions, odontoblasts have an important role such as protection from invasion of pathogens. In mammalian teeth, progenitors such as mesenchymal stem cells (MSCs) can migrate and differentiate into odontoblast-like cells, leading to the formation of reparative dentin. For differentiation using stem cells, it is crucial to provide conditions similar to the complex and intricate in vivo environment. The purpose of this study was to evaluate the potential of differentiation into odonto/ osteoblasts, and compare co-culture with/without epithelial cells. Methods: MSCs and epithelial cells were successfully isolated from dental tissues. We investigated the influences of epithelial cells on the differentiation process of dental pulp stem cells into odonto/osteoblasts using co-culture systems. The differentiation potential with/without epithelial cells was analyzed for the expression of specific markers and calcium contents. Results: Differentiated odonto/osteoblast derived from dental pulp tissue-derived mesenchymal stem cells with/without epithelial cells were evaluated by qRT-PCR, immunostaining, calcium content, and ALP staining. The expression of odonto/ osteoblast-specific markers, calcium content, and ALP staining intensity were significantly increased in differentiated cells. Moreover, the odonto/osteogenic differentiation capacity with epithelial cells co-culture was significantly higher than without epithelial cells co-culture. Conclusions: These results suggest that odonto/osteogenic differentiation co-cultured with epithelial cells has a more efficient application.

ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
    Chemicals and media
    Culture of dental pulp tissue derived mesenchymalstem cells (DP-MSCs)
    Isolation and culture of dental tissue-derived epithelialcells
    Flow cytometry analysis
    Differentiation into odonto/osteoblasts
    Real-time quantitative polymerase chain reaction
    Immunocytochemical stain
    Alkaline phosphatase activity
    Calcium colorimetric assay
    Statistical analysis
    Isolation and characterization of dental pulp tissuederivedMSCs and epithelial cells
    Odonto/osteogenic differentiation potential of DPMSCsusing epithelial cell co-culture system
RESULTS
DISCUSSION
CONCLUSION
REFERENCES

• Sang-Yun Lee(Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea, Stem Cell Convergence Research Center, Korea Research Institute Bioscience and Biotechnology, Daejeon 34141, Korea)
• Seong-Ju Oh(Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Rubel Miah(Department of Obstetrics, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea)
• Yong-Ho Choe(Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea)
• Sung-Lim Lee(Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Korea, Research Institute of Life Sciences, Gyeongsang National University, Jinju 52828, Korea)
• Yeon Woo Jeong(Department of Companion Animal and Animal Resources Science, Joongbu University, Geumsan 32713, Korea)
• Young-Bum Son(Department of Obstetrics, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea) Corresponding author