Department of Oral Diagnostics and Comprehensive Dentistry, Matsumoto Dental University Hospital, 1780 Hirooka-gobara, Shiojiri, Nagano, 399-0781, Japan.
Department of Oral Histology, Matsumoto Dental University, 1780 Hirooka-gobara, Shiojiri, Nagano, 399-0781, Japan.
J Oral Biosci. 2021 Jun;63(2):199-209. doi: 10.1016/j.job.2021.03.003. Epub 2021 Apr 15.
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.
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.
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.
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.
已有报道称 Wnt 信号参与牙本质桥的形成，但具体机制尚不清楚。本研究阐明了经典 Wnt 信号分子在牙本质桥形成过程中的定位。
暴露小鼠上颌第一磨牙的牙髓，并用 MTA 水泥直接覆盖。治疗后第 1、4、7、14 和 28 天采集上颌骨。在进行 μCT 分析后，对石蜡包埋切片进行 Wnt3a、Wnt10a、β-连环蛋白、F4/80 和骨钙素的免疫组织化学染色。
在牙髓覆盖后的第 4 和第 7 天，成牙本质细胞和成牙本质细胞表达 Wnt3a、Wnt10a 和 β-连环蛋白。在第 14 天，牙髓暴露区周围形成反应性牙本质。成牙本质细胞和成牙本质细胞表达 Wnt3a、Wnt10a 和 β-连环蛋白。此外，在牙髓中心还观察到 F4/80 和 Wnt10a 阳性的巨噬细胞。在第 28 天形成牙本质桥时，修复性成牙本质细胞表达 Wnt3a、β-连环蛋白和骨钙素。
成牙本质细胞和成牙本质细胞来源的 Wnt 配体对于牙本质桥形成过程中成牙本质细胞的激活和修复性成牙本质细胞的分化是重要的。巨噬细胞衍生的 Wnts 也参与修复性成牙本质细胞的分化。
