Format

Send to

Choose Destination
J Bone Miner Res. 2018 Mar;33(3):486-498. doi: 10.1002/jbmr.3330. Epub 2017 Nov 29.

Sclerostin Antibody Augments the Anabolic Bone Formation Response in a Mouse Model of Mechanical Tibial Loading.

Author information

1
Orthopaedic Research & Biotechnology Unit, The Children's Hospital at Westmead, Westmead, Australia.
2
Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Sydney, Australia.
3
Bone Biology Program, The Garvan Institute of Medical Research, Darlinghurst, Australia.
4
Novartis Pharma, Basel, Switzerland.

Abstract

Decreased activity or expression of sclerostin, an endogenous inhibitor of Wnt/β-catenin signaling, results in increased bone formation and mass. Antibodies targeting and neutralizing sclerostin (Scl-Ab) have been shown to increase bone mass and reduce fracture risk. Sclerostin is also important in modulating the response of bone to changes in its biomechanical environment. However, the effects of Scl-Ab on mechanotransduction are unclear, and it was speculated that the loading response may be altered for individuals receiving Scl-Ab therapy. To address this, we carried out a 2-week study of tibial cyclic compressive loading on C57Bl/6 mice treated with vehicle or 100 mg/kg/wk Scl-Ab. Increases in bone volume, density, and dynamic bone formation were found with loading, and the anabolic response was further increased by the combination of load and Scl-Ab. To investigate the underlying mechanism, gene profiling by RNA sequencing (RNAseq) was performed on tibias isolated from mice from all four experimental groups. Major alterations in Wnt/β-catenin gene expression were found with tibial loading, however not with Scl-Ab treatment alone. Notably, the combination of load and Scl-Ab elicited a synergistic response from a number of specific Wnt-related and mechanotransduction factors. An unexpected finding was significant upregulation of factors in the Rho GTPase signaling pathway with combination treatment. In summary, combination therapy had a more profound anabolic response than either Scl-Ab or loading treatment alone. The Wnt/β-catenin and Rho GTPase pathways were implicated within bone mechanotransduction and support the concept that bone mechanotransduction is likely to encompass a number of interconnected signaling pathways.

KEYWORDS:

ANABOLICS; BONE QCT/µCT; PRECLINICAL STUDIES; THERAPEUTICS; WNT/β-CATENIN/LRPS

PMID:
29090474
DOI:
10.1002/jbmr.3330
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center