Release of intact and fragmented osteocalcin molecules from bone matrix during bone resorption in vitro
(2004) In Journal of Biological Chemistry 279(18). p.18361-18369- Abstract
- Osteocalcin detected from serum samples is considered a specific marker of osteoblast activity and bone formation rate. However, osteocalcin embedded in bone matrix must also be released during bone resorption. To understand the contribution of each type of bone cell in circulating osteocalcin levels, we used immunoassays detecting different molecular forms of osteocalcin to monitor bone resorption in vitro. Osteoclasts were obtained from rat long bones and cultured on bovine bone slices using osteocalcin-depleted fetal bovine serum. In addition, human osteoclasts differentiated from peripheral blood mononuclear cells were used. Both rat and human osteoclasts released osteocalcin from bovine bone into medium. The amount of osteocalcin... (More)
- Osteocalcin detected from serum samples is considered a specific marker of osteoblast activity and bone formation rate. However, osteocalcin embedded in bone matrix must also be released during bone resorption. To understand the contribution of each type of bone cell in circulating osteocalcin levels, we used immunoassays detecting different molecular forms of osteocalcin to monitor bone resorption in vitro. Osteoclasts were obtained from rat long bones and cultured on bovine bone slices using osteocalcin-depleted fetal bovine serum. In addition, human osteoclasts differentiated from peripheral blood mononuclear cells were used. Both rat and human osteoclasts released osteocalcin from bovine bone into medium. The amount of osteocalcin increased in the presence of parathyroid hormone, a stimulator of resorption, and decreased in the presence of bafilomycin A1, an inhibitor of resorption. The amount of osteocalcin in the medium correlated with a well characterized marker of bone resorption, the C-terminal telopeptide of type I collagen (r > 0.9, p < 0.0001). The heterogeneity of released osteocalcin was determined using reverse phase high performance liquid chromatography, and several molecular forms of osteocalcin, including intact molecule, were identified in the culture medium. In conclusion, osteocalcin is released from the bone matrix during bone resorption as intact molecules and fragments. In addition to the conventional use as a marker of bone formation, osteocalcin can be used as a marker of bone resorption in vitro. Furthermore, bone matrix-derived osteocalcin may contribute to circulating osteocalcin levels, suggesting that serum osteocalcin should be considered as a marker of bone turnover rather than bone formation. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1130364
- author
- Ivaska, Kaisa LU ; Hentunen, Teuvo A ; Vaaraniemi, Jukka ; Ylipahkala, Hannele ; Pettersson, Kim and Vaananen, H Kalervo
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Biological Chemistry
- volume
- 279
- issue
- 18
- pages
- 18361 - 18369
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- pmid:14970229
- scopus:2442538224
- ISSN
- 1083-351X
- DOI
- 10.1074/jbc.M314324200
- language
- English
- LU publication?
- no
- id
- bab94d08-9643-45a6-9e59-1772fa1eb414 (old id 1130364)
- date added to LUP
- 2016-04-01 12:14:22
- date last changed
- 2022-04-29 02:28:55
@article{bab94d08-9643-45a6-9e59-1772fa1eb414,
abstract = {{Osteocalcin detected from serum samples is considered a specific marker of osteoblast activity and bone formation rate. However, osteocalcin embedded in bone matrix must also be released during bone resorption. To understand the contribution of each type of bone cell in circulating osteocalcin levels, we used immunoassays detecting different molecular forms of osteocalcin to monitor bone resorption in vitro. Osteoclasts were obtained from rat long bones and cultured on bovine bone slices using osteocalcin-depleted fetal bovine serum. In addition, human osteoclasts differentiated from peripheral blood mononuclear cells were used. Both rat and human osteoclasts released osteocalcin from bovine bone into medium. The amount of osteocalcin increased in the presence of parathyroid hormone, a stimulator of resorption, and decreased in the presence of bafilomycin A1, an inhibitor of resorption. The amount of osteocalcin in the medium correlated with a well characterized marker of bone resorption, the C-terminal telopeptide of type I collagen (r > 0.9, p < 0.0001). The heterogeneity of released osteocalcin was determined using reverse phase high performance liquid chromatography, and several molecular forms of osteocalcin, including intact molecule, were identified in the culture medium. In conclusion, osteocalcin is released from the bone matrix during bone resorption as intact molecules and fragments. In addition to the conventional use as a marker of bone formation, osteocalcin can be used as a marker of bone resorption in vitro. Furthermore, bone matrix-derived osteocalcin may contribute to circulating osteocalcin levels, suggesting that serum osteocalcin should be considered as a marker of bone turnover rather than bone formation.}},
author = {{Ivaska, Kaisa and Hentunen, Teuvo A and Vaaraniemi, Jukka and Ylipahkala, Hannele and Pettersson, Kim and Vaananen, H Kalervo}},
issn = {{1083-351X}},
language = {{eng}},
number = {{18}},
pages = {{18361--18369}},
publisher = {{American Society for Biochemistry and Molecular Biology}},
series = {{Journal of Biological Chemistry}},
title = {{Release of intact and fragmented osteocalcin molecules from bone matrix during bone resorption in vitro}},
url = {{http://dx.doi.org/10.1074/jbc.M314324200}},
doi = {{10.1074/jbc.M314324200}},
volume = {{279}},
year = {{2004}},
}