Journal of Bone and Mineral Metabolism

, Volume 25, Issue 1, pp 36–45

Characterization of osteoclasts derived from CD14+ monocytes isolated from peripheral blood


  • Mette Grøndahl Sørensen
    • Nordic Bioscience A/S
  • Kim Henriksen
    • Nordic Bioscience A/S
  • Sophie Schaller
    • Nordic Bioscience A/S
  • Dennis Bang Henriksen
    • Sanos Bioscience A/S
  • Finn Cilius Nielsen
    • Department of Clinical BiochemistryUniversity Hospital of Copenhagen
  • Morten Hanefeld Dziegiel
    • HS BlodbankUniversity Hospital of Copenhagen
    • Nordic Bioscience A/S

DOI: 10.1007/s00774-006-0725-9

Cite this article as:
Sørensen, M., Henriksen, K., Schaller, S. et al. J Bone Miner Metab (2007) 25: 36. doi:10.1007/s00774-006-0725-9


Bone resorption is solely mediated by osteoclasts. Therefore, a pure osteoclast population is of high interest for the investigation of biological aspects of the osteoclasts, such as the direct effect of growth factors and hormones, as well as for testing and characterizing inhibitors of bone resorption. We have established a pure, stable, and reproducible system for purification of human osteoclasts from peripheral blood. We isolated CD14-positive (CD14+) monocytes using anti-CD14-coated beads. After isolation, the monocytes are differentiated into mature osteoclasts by stimulation with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor κB ligand (RANKL). Osteoclast formation was only observed in the CD14+ population, not in the CD14− population, and only in the presence of both M-CSF and RANKL, confirming that the CD14+ system is a pure population of osteoclast precursors. No expression of osteoclast markers was observed in the absence of RANKL, whereas RANKL dose-dependently induced the expression of cathepsin K, tartrate-resistant acid phosphatase (TRACP), and matrix metallo proteinase (MMP)-9. Furthermore, morphological characterization of the cells demonstrated that actin rings were only formed in the presence of RANKL. Moreover, the osteoclasts were capable of forming acidic resorption lacunae, and inhibitors of lysosomal acidification attenuated this process. Finally, we measured the response to known bone resorption inhibitors, and found that the osteoclasts were sensitive to these and thereby provided a robust and valid method for interpretation of the effect of antiresorptive compounds. In conclusion, we have established a robust assay for developing osteoclasts that can be used to study several biological aspects of the osteoclasts and which in combination with the resorption marker CTX-I provides a useful tool for evaluating osteoclast function in vitro.

Key words

human osteoclastsCDMmorphologyresorptionosteoclastogenesis

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© Springer-Verlag Tokyo 2007