The role of canonical Wnt signaling in dentin bridge formation

Miroku Hara; Kanji Horibe; Hiroshi Mori; Hiroaki Nakamura

doi:10.1016/j.job.2021.03.003

The role of canonical Wnt signaling in dentin bridge formation

J Oral Biosci. 2021 Jun;63(2):199-209. doi: 10.1016/j.job.2021.03.003. Epub 2021 Apr 15.

Authors

Miroku Hara¹, Kanji Horibe², Hiroshi Mori¹, Hiroaki Nakamura³

Affiliations

¹ Department of Oral Diagnostics and Comprehensive Dentistry, Matsumoto Dental University Hospital, 1780 Hirooka-gobara, Shiojiri, Nagano, 399-0781, Japan.
² Department of Oral Histology, Matsumoto Dental University, 1780 Hirooka-gobara, Shiojiri, Nagano, 399-0781, Japan.
³ Department of Oral Histology, Matsumoto Dental University, 1780 Hirooka-gobara, Shiojiri, Nagano, 399-0781, Japan. Electronic address: hiroaki.nakamura@mdu.ac.jp.

PMID: 33845204
DOI: 10.1016/j.job.2021.03.003

Abstract

Objective: Wnt signaling has been reported to be involved in dentin bridge formation. However, the detailed mechanism has not yet been clarified. We elucidated the localization of canonical Wnt signaling molecules during dentin bridge formation.

Methods: Pulp of the maxillary first molar in mice was exposed and directly capped with MTA cement. Maxillae were collected on the 1st, 4th, 7th, 14th, and 28th days after treatment. After μCT analysis, immunohistochemistry for Wnt3a, Wnt10a, β-catenin, F4/80, and osterix was performed in paraffin-embedded sections.

Results: On the 4th and 7th days after pulp capping, odontoblasts and dental pulp cells expressed Wnt3a, Wnt10a, and β-catenin. On the 14th day, reactionary dentin was formed around the pulp exposure area. Odontoblasts and dental pulp cells express Wnt3a, Wnt10a, and β-catenin. Additionally, F4/80- and Wnt10a-positive macrophages were observed at the center of the dental pulp. When the dentin bridge was formed on the 28th day, reparative odontoblasts expressed Wnt3a, β-catenin and osterix.

Conclusion: Wnt ligands derived from odontoblasts and dental pulp cells are important for the activation of odontoblasts and the differentiation of reparative odontoblasts during dentin bridge formation. Macrophage-derived Wnts are also involved in reparative odontoblast differentiation.

Keywords: Dentin; Macrophages; Odontoblasts; Wnt signaling pathway.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Differentiation
Dental Pulp Capping
Dentin*
Mice
Odontoblasts
Wnt Signaling Pathway*