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Osteoclasts resorb protein-free mineral (Osteologic discs) efficiently in the absence of osteopontin.
- Source :
-
In vivo (Athens, Greece) [In Vivo] 2005 Mar-Apr; Vol. 19 (2), pp. 335-41. - Publication Year :
- 2005
-
Abstract
- Osteopontin (OPN) is both a matrix protein in mineralized tissues and a cytokine, and it has a pivotal role in osteoclast-mediated bone resorption. Here, using a proprietary hydroxyapatite substitute for bone mineral (Osteologic discs), we investigated the requirement for OPN in mineral resorption. Resorption pits formed in the Osteologic discs, revealed by staining with silver nitrite (Von Kossa stain), were analyzed using the NIH Image J program, which can determine the number of pits formed per unit area, their average size, and the fractional area resorbed. After a preincubation of bone marrow cells from OPN -/- and OPN +/+ mice with M-CSF to allow the multiplication of osteoclast precursors on cell culture plastic, osteoclast formation on both Osteologic discs and standard cell culture plates was induced with soluble receptor activator of NFkappaB ligand, sRANKL. We did not detect a dramatic difference in osteoclast formation between OPN +/+ and OPN -/- cells, as judged by staining for tartrate-resistant acid phosphatase in osteoclasts formed on cell culture plastic, nor was there a significant difference in the ability of the osteoclasts to form resorption pits in the Osteologic discs. Additionally, none of six different anti-OPN monoclonal antibodies had a significant and reproducible effect on the formation or subsequent functioning of the OPN+/+ osteoclasts. These studies suggest that, in contrast to what has been found for normal bone, the efficiency of dissolution of a ceramic, protein-free (excepting protein adsorbed from the culture medium) hydroxyapatite/tri-calcium phosphate substrate by osteoclasts is not substantially enhanced by endogenous or exogenous OPN.
- Subjects :
- Animals
Antibodies pharmacology
Bone Marrow Cells pathology
Cells, Cultured
Glycoproteins pharmacology
Macrophage Colony-Stimulating Factor pharmacology
Mice
Mice, Knockout
Osteoclasts drug effects
Osteopontin
Osteoprotegerin
Receptors, Cytoplasmic and Nuclear
Receptors, Tumor Necrosis Factor
Sialoglycoproteins genetics
Sialoglycoproteins immunology
Bone Resorption pathology
Durapatite metabolism
Osteoclasts pathology
Sialoglycoproteins physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0258-851X
- Volume :
- 19
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- In vivo (Athens, Greece)
- Publication Type :
- Academic Journal
- Accession number :
- 15796195