Rapidly growing Brtl/+ mouse model of osteogenesis imperfecta improves bone mass and strength with sclerostin antibody treatment.

Abstract

Osteogenesis imperfecta (OI) is a heritable collagen-related bone dysplasia, characterized by brittle bones with increased fracture risk that presents most severely in children. Anti-resorptive bisphosphonates are frequently used to treat pediatric OI and controlled clinical trials have shown that bisphosphonate therapy improves vertebral outcomes but has little benefit on long bone fracture rate. New treatments which increase bone mass throughout the pediatric OI skeleton would be beneficial. Sclerostin antibody (Scl-Ab) is a potential candidate anabolic therapy for pediatric OI and functions by stimulating osteoblastic bone formation via the canonical Wnt signaling pathway. To explore the effect of Scl-Ab on the rapidly growing OI skeleton, we treated rapidly growing 3week old Brtl/+ mice, harboring a typical heterozygous OI-causing Gly→Cys substitution on col1a1, for 5weeks with Scl-Ab. Scl-Ab had anabolic effects in Brtl/+ and led to new cortical bone formation and increased cortical bone mass. This anabolic action resulted in improved mechanical strength to WT Veh levels without altering the underlying brittle nature of the material. While Scl-Ab was anabolic in trabecular bone of the distal femur in both genotypes, the effect was less strong in these rapidly growing Brtl/+ mice compared to WT. In conclusion, Scl-Ab was able to stimulate bone formation in a rapidly growing Brtl/+ murine model of OI, and represents a potential new therapy to improve bone mass and reduce fracture risk in pediatric OI.

• Authors: Benjamin P Sinder, Joseph D Salemi, Michael S Ominsky, Michelle S Caird, Joan C Marini, Kenneth M Kozloff
• Journal: Bone (Bone) Vol. 71 Pg. 115-23 (Feb 2015) ISSN: 1873-2763 [Electronic] United States
• PMID: 25445450 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Adaptor Proteins, Signal Transducing
• Antibodies
• Glycoproteins
• Intercellular Signaling Peptides and Proteins
• Sost protein, mouse
• Osteocalcin

Topics

• Adaptor Proteins, Signal Transducing
• Animals
• Antibodies (pharmacology)
• Biomechanical Phenomena (drug effects)
• Body Weight (drug effects)
• Bone Development (drug effects)
• Bone and Bones (drug effects, pathology, physiopathology)
• Disease Models, Animal
• Female
• Femur (diagnostic imaging, drug effects, pathology)
• Glycoproteins (immunology)
• Growth Plate (drug effects, pathology)
• Intercellular Signaling Peptides and Proteins
• Male
• Mice
• Mice, Mutant Strains
• Organ Size (drug effects)
• Osteocalcin (blood)
• Osteogenesis Imperfecta (blood, pathology, physiopathology)
• X-Ray Microtomography