Effect of two different concentrations of 1α,25‑dihydroxyvitamin D3 on odontogenic differentiation of stem cells from human exfoliated deciduous teeth

Abstract

Background: Stem cells from human exfoliated deciduous teeth (SHEDs) can transform into
odontoblasts in vitro and in vivo. The role of 1α, 25‑dihydroxyvitamin D3 (1α,25 vitD3) has been reported
in the mineralization of hard tissues and teeth, as well as osteoblastic differentiation. This study aimed
to assess the effect of different concentrations of 1α,25 vitD3 on odontogenic differentiation of SHEDs.
Materials and Methods: In this experimental study, second‑passage SHEDs were exposed to
odontogenic medium along with 0, 10, 50, 100, and 150 nmol concentrations of in 1α, 25 vitD3 to determine
its optimal concentration for odontogenic differentiation. The methyl thiazolyl tetrazolium (MTT) assay
was performed. Odontogenic differentiation was evaluated by QRT‑ polymerase chain reaction for dentin
matrix protein (DMP1) and dentin sialophosphoprotein (DSPP) genes. Morphology of differentiated
cells was studied by Scanning Electron Microscopy. Data were analyzed using the Kruskal–Wallis, Mann–
Whitney, Friedman, and Chi‑square test. P < 0.05 is considered statistically significant.
Results: MTT test result showed the two groups of odontogenic medium + 10 nm 1α,25 vitD3 and
odontogenic medium + 150 nm 1α,25 vitD3 provided the most suitable conditions for cell viability
at 72 h. Expression of both genes significantly increased in the presence of 1α,25 vitD3 (P < 0.001).
Expression of both genes was significantly higher at 14 days compared with 7 days (P < 0.01). At
both time points, expression of both genes was significantly higher in the presence of 150 nm 1α,25
vitD3 compared with 10 nm (P < 0.01). The accumulation of cells with odontoblastic morphology,
cell interactions, and calcifications were evident.
Conclusion: 1α,25 vitD3 upregulates DMP1 and DSPP and results in odontogenic differentiation
of SHEDs in odontogenic medium. This upregulation increases with time and by an increase in
concentration of 1α,25 vitD3.
Key Words: Deciduous teeth, dental pulp, stem cells