Tissue-resident macrophages in dental pulp regulate the microenvironment for reparative dentine formation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H04400
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Dental engineering/Regenerative dentistry
• Research Institution: Matsumoto Dental University
• Principal Investigator: Nakamura Hiroaki 松本歯科大学, 歯学部, 教授 (50227930)
• Co-Investigator(Kenkyū-buntansha): 二宮 禎 日本大学, 歯学部, 准教授 (00360222) ; 宇田川 信之 松本歯科大学, 歯学部, 教授 (70245801) ; 細矢 明宏 北海道医療大学, 歯学部, 准教授 (70350824) ; 堀部 寛治 松本歯科大学, 歯学部, 助教 (70733509) ; 雪田 聡 静岡大学, 教育学部, 准教授 (80401214)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 修復象牙質 / マクロファージ / 歯髄組織 / Wntシグナル / 歯髄再生療法

Outline of Final Research Achievements

We investigated the localization of Wnt-related molecules and F4/80-positive macrophages in the process of reparative dentin formation. After directly pulp-capping with MTA cement in the upper first molars of mice, reparative dentin formation was confirmed 14 days after direct pulp capping by micro-CT analysis. Histological analysis revealed that odontoblasts arrayed on the surface of reparative dentin were positive for Wnt3a and Wnt10a.b-catenin was localized in their nucleus. Additionally, F4/80-positive macrophages in the pulp expressed Wnt10a. The localization of b-catenin was found in the nucleus of pulp cells surrounding macrophages. These results suggest that odontoblast- and macrophage-derived Wnt were involved in the reparative odontoblast differentiation.

Free Research Field

口腔解剖学

Academic Significance and Societal Importance of the Research Achievements

本研究は、MTAセメントを取り込んだマクロファージがWnt10aを発現することにより、修復象牙芽細胞分化に深く関わっていることを明らかにしたものである。この現象はこれまでに報告されておらず、今後の歯髄保存療法に多くの示唆を与えるものである。また、Wnt/b-カテニンシグナル以外のマクロファージ由来成長因子が明らかになれば、歯髄保存療法への応用でき、歯科医療の発展に貢献できると考えている。