Enhanced Expression of Reprogramming Markers in Odontogenic Cells with Co-culture

Objectives: Dental papilla and dental follicle enables dental papilla cells (DPCs) and dental follicle cells (DFCs), as odontogenic cells, to communicate with each other during tooth development. POU5F1, SOX2, and MYC are known to play regulatory role in reprogramming and pluripotency. Therefore, it is interesting to know whether the expression of reprogramming markers is related to cell-cell communication.
Methods: In this study, an in-vitro co-culture system of DPCs and DFCs was established. Cell proliferation, cell apoptosis cell cycle stages, and expression of POU5F1, SOX2, and MYC were investigated by CCK8 analysis, flow cytometry, real-time PCR, and immunohistochemical staining. The distribution of POU5F1, SOX2, and MYC in rat tooth germ was also investigated by immunohistochemical staining.
Results: Ours results revealed that 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 POU5F1 and SOX2 was significantly elevated in both cell types after 3 d of co-culture, whereas expression of MYC was not significantly elevated until day 5. POU5F1 and SOX2 were strongly expressed in tooth germ on days 7 and 9 after birth, whereas MYC was expressed only on day 9.
Conclusions: These results indicated that the optimized microenvironment with cell-cell communication enhanced the expression of reprogramming markers associated with reprogramming capacity in DPCs and DFCs, both in-vitro and in-vivo.