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.

Colorectal Cancer-Associated Genes Are Associated with Tooth Agenesis and May Have a Role in Tooth Development

“…Enhancer elements of cMYC are known to be up to 500 Mb away from the gene start site, therefore it is possible that the CASC8 SNP may be in a LD block associated with cMYC enhancer elements and drive the association findings 47 . The presence of Myc has been detected in dental pulp cells, dental follicle cells, ameloblasts and odontoblasts, and could be related to cell reprogramming or differentiation during tooth development 48 .…”

Non‐syndromic cleft lip with or without palate susceptible loci is associated with tooth agenesis

“…MYC was involved in tooth development. Its expression was detected in dental pulp cells, dental follicle cells, ameloblasts, and odontoblasts and was related to cell reprogramming and differentiation during tooth development (Peng, Liu, Wei, & Ling, ), implicating a role of rs4791774 in the tooth and craniofacial development. Here, rs4791774 exhibited a nominal association and decreased risk with TA after Bonferroni correction, whereas this locus showed increased odds to NSCL/P in our previous GWAS (Sun et al, ).…”

Non‐syndromic cleft lip with or without palate‐susceptible SNPs is associated with hyperdontia

“…Myc_disc7 belongs to the MYC family that contains three principle members ( C‐MYC , N‐MYC , and L‐MYC ). C‐MYC was involved in teeth development and could be detected in the early stage of dental pulp cells (Peng, Liu, Wei, & Ling, ). Yoshimura et al claimed that L‐Myc and N‐Myc could reprogram mouse embryonic fibroblasts to induced pluripotent stem cells (iPSC) (Oda et al, ).…”

“…Myc_disc7 belongs to the MYC family that contains three principle members (C-MYC, N-MYC, and L-MYC). C-MYC was involved in teeth development and could be detected in the early stage of dental pulp cells (Peng, Liu, Wei, & Ling, 2014). population.…”