Biological action of PTH/PTHrP on bone-specific blood vessels and osteo-vascular interaction

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H03103
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 57010:Oral biological science-related
• Research Institution: Hokkaido University
• Principal Investigator: Amizuka Norio 北海道大学, 歯学研究院, 教授 (30242431)
• Co-Investigator(Kenkyū-buntansha): 長谷川 智香 北海道大学, 歯学研究院, 准教授 (50739349)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 骨芽細胞 / 骨特異的血管 / PTH / PTHrP / 骨血管連関

Outline of Final Research Achievements

In this study, we analyzed how PTH/PTHrP affects mature osteoblasts, osteoblast progenitor cells, vascular endothelial cells and vascular smooth muscle cells, or undifferentiated mesenchymal cells in long bones using animal models. As a result, PTH/PTHrP increased the number of undifferentiated mesenchymal cells in the metaphyseal trabeculae from the embryonic to the adult stage. The increased undifferentiated mesenchymal cells differentiated into osteoblast lineage cells on the metaphyseal trabeculae at the embryonic stage, while they differentiated into both osteoblast lineage cells and vascular lineage cells at the adult stage. However, PTH/PTHrP may not contribute to increase the undifferentiated mesenchymal cells and their differentiation into osteoblast in the cortical bone.

Free Research Field

組織学、骨代謝学、微細構造学

Academic Significance and Societal Importance of the Research Achievements

PTH/PTHrPは、従来、骨芽細胞系細胞へのanabolic作用のみが注目されてきた。本研究から、PTH/PTHrPが骨芽細胞系細胞のみならず骨特異的血管にも作用すること、また、骨幹端部の未分化間葉系細胞の増殖・分化にも寄与することが明らかとされた。一方、未分化間葉系細胞の分化については時期によって異なること、また、このような作用は皮質骨では見られない可能性が示唆された。これらの結果は、PTHが骨幹端では骨梁増加を、皮質骨では多孔化を誘導するといった相反作用の解明につながると考えられた。