Investigation for involvement of MMP-2 in bone healing with imaging of proteome and mineralome

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K09825
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57010:Oral biological science-related
• Research Institution: Tohoku University
• Principal Investigator: Sasano Yasuyuki 東北大学, 歯学研究科, 教授 (30196191)
• Co-Investigator(Kenkyū-buntansha): Yang MuChen 東北大学, 歯学研究科, 助教 (50886447) ; 鈴木 治 東北大学, 歯学研究科, 教授 (60374948) ; 矢尾 育子 関西学院大学, 生命環境学部, 教授 (60399681)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: MMP-2欠損マウス / 脛骨 / 骨密度 / マイクロX線CT / エネルギー分散型X線分析 / 破骨細胞 / 下顎頭 / 骨髄腔

Outline of Final Research Achievements

he present study was designed to compare calcification and histological characteristics of tibiae between the mice devoid of matrix metalloproteinase (MMP)-2 (KO) and the wild-type mice (WT). Calcification was examined using the micro-computed tomography (micro-CT) for the bone mineral density (BMD) and the scanning electron microscope equipped with an energy dispersive X-ray spectroscope (SEM-EDX) for analysis of elements that constitute the calcium phosphate mineral. Histological sections were cut and stained with hematoxylin and eosin or alcian blue. The BMD of the cortical bone was lower in KO whereas element concentrations and distributions were not different between KO and WT. Histology showed that the cortical bone is thinner and its surface facing the bone marrow is more irregular in KO. The present study suggested that MMP-2 has some role in bone calcification and histological organization.

Free Research Field

口腔組織発生学　口腔解剖学

Academic Significance and Societal Importance of the Research Achievements

MMP-2が骨の石灰化に役割を担うことは想定されてきたが、ミネラルにおける元素の構成や組織構造への影響は不明である。本研究ではMMP-2遺伝子欠損マウスで生後７週齢及び２５週齢の段階の骨密度が低下する傾向を確認した一方で、カルシウムとリンの濃度には野生型マウスと違いは見られなかった。組織学的検討では、MMP-2遺伝子欠損マウスで皮質骨が薄く、また、骨髄腔に面する骨面の凹凸が顕著で、破骨細胞の関与が示唆された。