Clarification of osteoblast differentiation promotion mechanism by polycomb group protein Bmi1 and alveolar bone regeneration

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K17090
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57040:Regenerative dentistry and dental engineering-related
• Research Institution: Health Sciences University of Hokkaido
• Principal Investigator: TAKEBE Hiroaki 北海道医療大学, 歯学部, 助教 (40638293)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 骨芽細胞 / Bmi1 / Shh

Outline of Final Research Achievements

Bmi1 is thought to regulate the expression of differentiation-related genes during development. So far, the present investigators have clarified experimentally that Bmi1 is expressed in osteoblasts and that osteogenic ability is increased by gene transfer into established osteoblasts. Therefore, in this study, in order to search the localization of Bmi1 and its related factor, Sonic hedgehog (Shh) in the endochondral ossification process, experiments were conducted using a tibial development model and a tibial fracture model. Bmi1 showed positive reactions during the tibial development and fracture repair processes. Furthermore, Shh was localized during the fracture repair process. These results indicate that Bmi1 and Shh are involved in endochondral ossification and fracture repair process.

Free Research Field

組織学

Academic Significance and Societal Importance of the Research Achievements

骨芽細胞の分化には、BMPs2をはじめとする転写調節因子などの関与が重要であると考えられている。しかし、骨再生時において骨形成を促進する遺伝子については、どの分子が重要であるのかは不明である。近年、Bmi1遺伝子を全身性に欠損したマウスに骨および歯の成長遅延が認められることが報告された。しかし、これまで硬組織形成過程におけるBmi1陽性細胞の局在は報告されておらず、成長遅延は間葉系幹細胞の機能不全に由来すると考えられてきた。本研究では免疫組織化学的手法よりBmi1が骨芽細胞分化に関連していることが明らかとなった。これらの結果は再生歯科医学に有用なツールになる可能性がある。