The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Osteoblast-like cells complete osteoclastic bone resorption and form new mineralized bone matrix in vitro

På svenska

Author

  • MTK Mulari
  • Q Qu
  • Pirkko Härkönen
  • HK Vaananen

Summary, in English

Bone remodeling involves old bone resorption by osteoclasts and new bone formation by osteoblasts. However, the precise cellular mechanisms underlying these consecutive events remain obscure. To address this question in vitro, we have established a cell culture model in which the resorption lacunae are first created by osteoclasts and osteoblast-like cells accomplish the subsequent bone formation. We isolated osteoclasts from rat bone marrow and cultured them on bovine bone slices for 48 hours to create resorption lacunae. After removing osteoclasts, confluent differentiated primary osteoblast cultures were trypsinized and the cells were replaced on the resorbed bone slices for up to 14 days. The cultures were then examined by confocal microscopy, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Our data suggest that after osteoclastic bone resorption, osteoblast-like cells, not macrophages, remove the remaining organic matrix in the lacuna. After cleaning the lacuna, osteoblast-like cells deposit new collagen fibrils at the bottom of the lacuna and calcify the newly formed matrix only, as visualized by labeled tetracycline accumulation merely in the lacuna during the osteoblast culture. Furthermore, an electron-dense layer rich in osteopontin separates the old and new matrices suggesting formation of the cement line. Since the morphology of the newly formed matrix is similar to the natural bone with respect to the cement line and osteoid formation as well as matrix mineralization, the present method provides for the first time a powerful in vitro method to study the cellular mechanisms leading to bone remodeling also in vivo.

Publishing year

2004

Language

English

Pages

253-261

Publication/Series

Calcified Tissue International

Volume

75

Issue

3

Document type

Journal article

Publisher

Springer

Topic

  • Cancer and Oncology

Keywords

  • Bone remodeling
  • Bone resorption
  • Osteoblast
  • Osteoclast
  • Osteopontin

Status

Published

ISBN/ISSN/Other

  • ISSN: 1432-0827