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Published in: Osteoporosis International 4/2012

01-04-2012 | Original Article

Omentin-1 exerts bone-sparing effect in ovariectomized mice

Authors: H. Xie, P.-L. Xie, X.-H. Luo, X.-P. Wu, H.-D. Zhou, S.-Y. Tang, E.-Y. Liao

Published in: Osteoporosis International | Issue 4/2012

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Abstract

Summary

Omentin-1 inhibited osteoblast differentiation in vitro. In co-culture systems of osteoblasts and osteoclast precursors, omentin-1 reduced osteoclast formation by stimulating osteoprotegerin (OPG) and inhibiting receptor activator for nuclear factor κB ligand (RANKL) production in osteoblasts. In vivo, adenovirus-mediated overexpression of omentin-1 suppressed bone turnover and restored bone mineral density (BMD) and bone strength in ovariectomized mice.

Introduction

Omentin-1 (also intelectin-1) is a recently identified visceral adipose tissue-derived cytokine that is highly abundant in plasma. This study was undertaken to investigate the effects of omentin-1 on bone metabolism.

Methods

Osteoblast differentiation was assessed by measuring alkaline phosphatase activity, osteocalcin production and matrix mineralization. OPG and RANKL protein expression and secretion in osteoblasts were detected by Western blot and ELISA, respectively. The effect of recombinant omentin-1 on osteoclast formation was examined in co-culture systems of osteoblasts and osteoclast precursors. The effects of intravenous administration of adenoviral-delivered omentin-1 on bone mass, bone strength, and bone turnover were also examined in ovariectomized mice.

Results

In vitro, omentin-1 inhibited osteoblast differentiation, while it had no direct effect on osteoclast differentiation; it also reduced osteoclast formation in the co-culture systems through stimulating OPG and inhibiting RANKL production in osteoblasts. In vivo, adenovirus-mediated overexpression of omentin-1 partially restored BMD and bone strength in ovariectomized mice, accompanied by decreased levels of plasma osteocalcin and tartrate-resistant acid phosphatase-5b and lower serum RANKL/OPG ratios.

Conclusion

The present study suggests that omentin-1 ameliorates bone loss induced by estrogen deficiency via downregulating the RANKL/OPG ratio.
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Metadata
Title
Omentin-1 exerts bone-sparing effect in ovariectomized mice
Authors
H. Xie
P.-L. Xie
X.-H. Luo
X.-P. Wu
H.-D. Zhou
S.-Y. Tang
E.-Y. Liao
Publication date
01-04-2012
Publisher
Springer-Verlag
Published in
Osteoporosis International / Issue 4/2012
Print ISSN: 0937-941X
Electronic ISSN: 1433-2965
DOI
https://doi.org/10.1007/s00198-011-1697-8

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