title: Expression of Oct-4, SOX-2, and MYC in dental papilla cells and dental follicle cells during in-vivo tooth development and in-vitro co-culture.
abstract: During tooth development, the special structure of dental follicle and dental papilla enables dental papilla cells (DPCs) and dental follicle cells (DFCs) to make contact with each other. Octamer-binding transcription factor 4 (Oct-4), sex determining region Y box-2 (SOX-2), and cellular homologue of avian myelocytomatosis virus oncogene (MYC) (OSM) are associated with reprogramming and pluripotency. However, whether the expression of OSM could be activated through cell-cell communication is not known. In this study, the distribution of OSM in rat tooth germ was investigated by immunohistochemical staining. An in-vitro co-culture system of DPCs and DFCs was established. Cell proliferation, cell apoptosis, cell cycle stages, and expression of OSM were investigated by Cell Counting Kit 8 (CCK8) analysis, flow cytometry, real-time PCR, and immunohistochemical staining. We found that Oct-4 and SOX-2 were strongly expressed in tooth germ on days 7 and 9 after birth, whereas MYC was expressed only on day 9. Cell proliferation and apoptosis were inhibited, the cell cycle was arrested in the G0/G1 phase, and the propidium iodide (PI) value was downregulated. Expression of Oct-4 and SOX-2 was significantly elevated in both cell types after 3 d of co-culture, whereas expression of MYC was not significantly elevated until day 5. These results indicate that the optimized microenvironment with cell-cell communication enhanced the expression of reprogramming markers associated with reprogramming capacity in DPCs and DFCs, both in vivo and in vitro.
authors.affiliation: Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Guangdong Province Key Laboratory of Stomatology Guangzhou, Sun Yat-Sen University, Guangdong, China.
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Peng
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.forename: Xi
authors.initials: X
authors.lastname: Wei
authors.forename: Junqi
authors.initials: J
authors.lastname: Ling
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002450:Cell Communication / Q000502:physiology; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D060833:Cellular Microenvironment / Q000502:physiology; D065150:Cellular Reprogramming / Q000502:physiology; D018920:Coculture Techniques; D003771:Dental Papilla / Q000166:cytology*; D003795:Dental Sac / Q000166:cytology*; D016193:G1 Phase / Q000502:physiology; D050814:Octamer Transcription Factor-3 / Q000032:analysis*; D009805:Odontogenesis / Q000502:physiology*; D039904:Pluripotent Stem Cells / Q000502:physiology; D016271:Proto-Oncogene Proteins c-myc / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016192:Resting Phase, Cell Cycle / Q000502:physiology; D055748:SOXB1 Transcription Factors / Q000032:analysis*; D013997:Time Factors; D014083:Tooth Germ / Q000166:cytology / Q000502:physiology
chemical_list: D050814:Octamer Transcription Factor-3; D016271:Proto-Oncogene Proteins c-myc; D055748:SOXB1 Transcription Factors; C527784:Sox2 protein, rat
keywords: dental follicle cells; dental papilla cells; microenvironment; reprogramming; tooth development