Elucidation of the mechanism by which tooth loss causes cognitive decline

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K10035
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57050:Prosthodontics-related
• Research Institution: Hiroshima University
• Principal Investigator: Oue Hiroshi 広島大学, 医系科学研究科(歯), 助教 (70711307)
• Co-Investigator(Kenkyū-buntansha): 竹田 洋輔 北海道医療大学, 歯学部, 助教 (80812560) ; 横井 美有希 広島大学, 病院(歯), 助教 (90826869)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 歯の喪失

Outline of Final Research Achievements

The purpose of this study was to elucidate the molecular biological mechanism by which tooth loss causes cerebrovascular disorders similar to AD and other dementias. We created an experimental group in which experimental tooth loss was induced by extraction of mouse molars, and oral functions were impaired. After the observation period, behavioral experiments such as the Barnes maze were conducted to measure learning and memory abilities. Brain tissue was then collected and subjected to Western blot analysis and immunohistochemical staining.
The results revealed that experimental tooth loss reduced learning and memory performance and affected the tight junctions of the blood-brain barrier (BBB), which is important for cerebrovascular function. This is the first report of the effects of tooth loss on the BBB and is a new finding.

Free Research Field

歯学

Academic Significance and Societal Importance of the Research Achievements

歯の喪失と認知機能が関連することは従来疫学研究で示されているが，そのメカニズムは不明である。アルツハイマー病(AD)など認知症患者の多くは脳血管障害を伴うことが明らかとなってきたことから，歯の喪失が認知機能低下を引き起こすメカニズムを脳血管機能に着目して明らかにできるのではと着想した。実験的な歯の喪失により，学習記憶能が低下し，脳血管機能に重要な血液脳関門（BBB）のタイトジャンクションに影響を与えることが明らかとなった。歯の喪失によるBBBへの影響を報告はこれまでになく，新たな知見が得られた。