2021 Fiscal Year Final Research Report

Wound and repair mechanism in ovariectomized rats with periodontitis -Direct action of estrogen and transition of HSP expression

Research Project

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Project/Area Number	19K10862
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 58060:Clinical nursing-related
Research Institution	Kanagawa Dental College
Principal Investigator	Amano Kaori 神奈川歯科大学, 歯学部, 准教授 (70316470)
Project Period (FY)	2019-04-01 – 2022-03-31
Keywords	OVX / エストロゲン欠乏 / 実験的歯周炎 / 軽度機械刺激と損傷 / β-エストラジオール / C-Fos / HSP70 / 唾液分泌減少
Outline of Final Research Achievements	The aim of this study was to observe the level of tissue cell disruption in OVX rats when inflammation such as periodontitis was induced in an estrogen-deficient environment. A total of 30 female rats were used in this experiment: 24 eight-week-old OVX rats in the experimental group and 6 sham rats in the control group. To induce periodontitis, P. gingivalis (P. g) was used. OVX rats were further divided into three: regular food, food containing soy isoflavones, and implanted with E2 pellets. After 60 days, the mandibular central incisor gingiva and the tongue were brushed with an electric toothbrush under anesthesia for 1 minute. 3 hours after brushing, all rats were perfused . C-fos and HSP70 antibody was used as the labeling marker for the injured cells. C-fos expression was abundantly observed in the injured cells of both gum and tongue muscle tissue just below the epithelium in the P.g infected group. HSP70 expression in OVX rats were clearly lower than that in sham rats.
Free Research Field	形態構造
Academic Significance and Societal Importance of the Research Achievements	歯周炎の罹患率は40歳以降から急速に上昇するが, 特に閉経前後に増加傾向となる病態機構について, エストロゲンの減少が直接影響しているか否かは未だに解明されていない。骨粗鬆症との関連性が報告されているが現段階では,あくまで憎悪因子の一つという位置づけとなる。一方, 歯周炎の直接因子と考えられている加齢に伴う唾液分泌量の減少がエストロゲン補充により軽減すると多数の報告があり, エストロゲン欠乏は種々のリスク因子上昇に確実に関与しているといえる。本課題の意義は実験的に歯周炎を惹起させたOVXラットを使用しエストロゲン補充が歯周炎の進行に直接関与するのか否かを解明する事である。