Compressive loading of the murine tibia reveals site : specific micro-scale differences in adaptation and maturation rates of bone
|Author:||Bergström, I.1; Kerns, J. G.2,3; Törnqvist, A. E.4;|
1Department of Endocrinology, Metabolism and Diabetes, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
2UCL Institute of Orthopedics and Musculoskeletal Science, Royal National Orthopedic Hospital, London, UK
3Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
4Rheumatology and Bone Diseases Unit, Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, UK
5Department of Biomedical Engineering and Department of Orthopedics, Lund University, Lund, Sweden
6Institute of Cancer and Translational Medicine, Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
7Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
8Department of Orthopedics, Sahlgrenska University Hospital, Gothenburg, Sweden
9Department of Laboratory Medicine, Division of Pathology, Karolinska University Hospital, Karolinska Institutet, Huddinge, Stockholm, Sweden
10Centre for Comparative and Clinical Anatomy, School of Veterinary Science, University of Bristol, Bristol, UK
11Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
|Online Access:||PDF Full Text (PDF, 0.8 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2019101032119
|Publish Date:|| 2019-10-10
Summary: Loading increases bone mass and strength in a site-specific manner; however, possible effects of loading on bone matrix composition have not been evaluated. Site-specific structural and material properties of mouse bone were analyzed on the macro- and micro/molecular scale in the presence and absence of axial loading. The response of bone to load is heterogeneous, adapting at molecular, micro-, and macro-levels.
Introduction: Osteoporosis is a degenerative disease resulting in reduced bone mineral density, structure, and strength. The overall aim was to explore the hypothesis that changes in loading environment result in site-specific adaptations at molecular/micro- and macro-scale in mouse bone.
Methods: Right tibiae of adult mice were subjected to well-defined cyclic axial loading for 2 weeks; left tibiae were used as physiologically loaded controls. The bones were analyzed with μCT (structure), reference point indentation (material properties), Raman spectroscopy (chemical), and small-angle X-ray scattering (mineral crystallization and structure).
Results: The cranial and caudal sites of tibiae are structurally and biochemically different within control bones. In response to loading, cranial and caudal sites increase in cortical thickness with reduced mineralization (−14 and −3%, p < 0.01, respectively) and crystallinity (−1.4 and −0.3%, p < 0.05, respectively). Along the length of the loaded bones, collagen content becomes more heterogeneous on the caudal site and the mineral/collagen increases distally at both sites.
Conclusion: Bone structure and composition are heterogeneous, finely tuned, adaptive, and site-specifically responsive at the micro-scale to maintain optimal function. Manipulation of this heterogeneity may affect bone strength, relative to specific applied loads.
|Pages:||1121 - 1131|
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
3141 Health care science
318 Medical biotechnology
This study was supported by the Swedish Research Council (K2015-99X-10363-23-4, 2013-455, and 2013-2852), the ALF/LUA research grant in Gothenburg (ALFGBG-434111) and Stockholm, and the Engineering and Physical Sciences Research Council (EP/H002693/1).
© The Author(s) 2016. The original article https://doi.org/10.1007/s00198-016-3846-6 may be re-used and distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. The copyright of the original article retains with the author(s).