Ultrastructural examination on osteolysis and calcification induced by osteocyte

2017 Fiscal Year Final Research Report

• Project/Area Number: 16H06602
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Morphological basic dentistry
• Research Institution: Hokkaido University
• Principal Investigator: Hongo Hiromi 北海道大学, 歯学研究院, 学術研究員 (00778970)
• Project Period (FY): 2016-08-26 – 2018-03-31
• Keywords: 骨細胞性骨溶解 / 骨細胞 / 石灰化沈着

Outline of Final Research Achievements

In this study, we have attempted to histologically verify “osteocytic osteolysis”, using two mice models - RANKL-/- mice lacking osteoclasts and lactating mice fed with calcium (Ca) insufficient diet, which decreased the serum concentration of Ca. Nanoindentation of AFM revealed decreased modulus of elasticity surrounding bone matrix of osteocytes in these model mice. Under TEM observation, there are some fragmented collagen fibrils and pieces of mineralized matrices in the enlarged osteocytic lacunae which showed irregularly-shaped walls. Furthermore, we observed a layer of bone matrix parallel to the configuration of enlarged osteocytic lacunae. Under isotope microscopy using 42Ca stable isotope, the deposition of 42Ca isotope could be observed surrounding the osteocytic lacunae. It seems likely, therefore, that osteocytes enable to erode the surrounding bone matrix and deposit minerals on their lacunae.

Free Research Field

組織化学