Introduction: Oxytocin (OT) is a neurohypophysial hormone that plays a role in lactation and parturition and exerts diverse biological actions via the OT receptor. Recently, several studies have reported that OT stimulates bone formation by osteoblasts in osteoporosis. We focused on OT and hypothesized that OT can stimulate the differentiation of odontoblasts as well as osteoblasts. The aim of this study was to verify whether OT is an essential factor in dentinogenesis; we examined the effects of OT on dentinogenesis using a long-term culture system of rat dental pulp cells.
Methods: Using a culture system of rat dental pulp cells with Otr knocked out by CRISPR-Cas9 genome editing, we examined the effects of OT on odontoblastlike cell differentiation as reflected by dentin formation.
Results: We confirmed that OT stimulated mineralized nodule formation and the expression of both dentin sialoprotein and bone Gla protein messenger RNAs (mRNAs) in the culture system. Interestingly, the cultured cells treated with OT also exhibited an increase of both Wnt10a and Lef-1 mRNA. The Otr knockout cells showed inhibition of nodule formation and mRNA expression, and these phenomena remained despite OT treatment. These results indicate the following: OT regulates odontoblastlike cell differentiation via the OT receptor, it stimulates dentin formation, and the Wnt canonical pathway is closely related to these effects.
Conclusions: The present results suggest that OT can promote odontoblastlike cell differentiation, resulting in increased dentin formation, and that OT could be an important factor for dentinogenesis.
Keywords: Differentiation; Wnt signaling; odontoblast; oxytocin; oxytocin receptor.
Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.