Expression and function of dopamine in odontoblasts. Issue 5 (15th October 2019) - Fujino, Shoko
Abstract: Dopamine (DA) is produced from tyrosine by tyrosine hydroxylase (TH). A recent study has reported that DA promotes the mineralization of murine preosteoblasts. However, the role of DA in odontoblasts has not been examined. Therefore, in this investigation, we researched the expression of TH and DA in odontoblasts and the effects of DA on the differentiation of preodontoblasts (KN‐3 cells). Immunostaining showed that TH and DA were intensely expressed in odontoblasts and preodontoblasts of rat incisors and molars. KN‐3 cells expressed D1 ‐like and D2 ‐like receptors for DA. Furthermore, DA promoted odontoblastic differentiation of KN‐3 cells, whereas an antagonist of D1‐like receptors and a PKA signaling blocker, inhibited such differentiation. However, antagonists of D2‐like receptors promoted differentiation. These results suggested that DA in preodontoblasts and odontoblasts might promote odontoblastic differentiation through D1‐like receptors, but not D2‐like receptors, and PKA signaling in an autocrine or paracrine manner and plays roles in dentinogenesis. Abstract : Our study revealed that tyrosine hydroxylase (TH) and dopamine (DA) were expressed in preodontoblasts and mature odontoblasts and that DA promoted odontoblastic differentiation of preodontoblasts through DA receptors (Drd1 or Drd5) and PKA signaling. These results allow us to better understand the detailed mechanism of dentinogenesis and may be useful for the development of dental pulp capping agents.