1
|
Arora D, Taylor EA, King KB, Donnelly E. Increased tissue modulus and hardness in the TallyHO mouse model of early onset type 2 diabetes mellitus. PLoS One 2023; 18:e0287825. [PMID: 37418415 PMCID: PMC10328374 DOI: 10.1371/journal.pone.0287825] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 06/14/2023] [Indexed: 07/09/2023] Open
Abstract
Individuals with type 2 diabetes mellitus (T2DM) have a higher fracture risk compared to those without T2DM despite having higher bone mineral density (BMD). Thus, T2DM may alter other aspects of resistance to fracture beyond BMD such as bone geometry, microarchitecture, and tissue material properties. We characterized the skeletal phenotype and assessed the effects of hyperglycemia on bone tissue mechanical and compositional properties in the TallyHO mouse model of early-onset T2DM using nanoindentation and Raman spectroscopy. Femurs and tibias were harvested from male TallyHO and C57Bl/6J mice at 26 weeks of age. The minimum moment of inertia assessed by micro-computed tomography was smaller (-26%) and cortical porosity was greater (+490%) in TallyHO femora compared to controls. In three-point bending tests to failure, the femoral ultimate moment and stiffness did not differ but post-yield displacement was lower (-35%) in the TallyHO mice relative to that in C57Bl/6J age-matched controls after adjusting for body mass. The cortical bone in the tibia of TallyHO mice was stiffer and harder, as indicated by greater mean tissue nanoindentation modulus (+22%) and hardness (+22%) compared to controls. Raman spectroscopic mineral:matrix ratio and crystallinity were greater in TallyHO tibiae than in C57Bl/6J tibiae (mineral:matrix +10%, p < 0.05; crystallinity +0.41%, p < 0.10). Our regression model indicated that greater values of crystallinity and collagen maturity were associated with reduced ductility observed in the femora of the TallyHO mice. The maintenance of structural stiffness and strength of TallyHO mouse femora despite reduced geometric resistance to bending could potentially be explained by increased tissue modulus and hardness, as observed at the tibia. Finally, with worsening glycemic control, tissue hardness and crystallinity increased, and bone ductility decreased in TallyHO mice. Our study suggests that these material factors may be sentinels of bone embrittlement in adolescents with T2DM.
Collapse
Affiliation(s)
- Daksh Arora
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York, United States of America
| | - Erik A. Taylor
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, United States of America
| | - Karen B. King
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Eve Donnelly
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York, United States of America
- Research Institute, Hospital for Special Surgery, New York, New York, United States of America
| |
Collapse
|
2
|
Molstad DHH, Mattson AM, Begun DL, Westendorf JJ, Bradley EW. Hdac3 regulates bone modeling by suppressing osteoclast responsiveness to RANKL. J Biol Chem 2021; 295:17713-17723. [PMID: 33454009 DOI: 10.1074/jbc.ra120.013573] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 09/30/2020] [Indexed: 11/06/2022] Open
Abstract
Hdac3 is a lysine deacetylase that removes acetyl groups from histones and additional proteins. Although Hdac3 functions within mesenchymal lineage skeletal cells are defined, little is known about Hdac3 activities in bone-resorbing osteoclasts. In this study we conditionally deleted Hdac3 within Ctsk-expressing cells and examined the effects on bone modeling and osteoclast differentiation in mice. Hdac3 deficiency reduced femur and tibia periosteal circumference and increased cortical periosteal osteoclast number. Trabecular bone was likewise reduced and was accompanied by increased osteoclast number per trabecular bone surface. We previously showed that Hdac3 deacetylates the p65 subunit of the NF-κB transcriptional complex to decrease DNA-binding and transcriptional activity. Hdac3-deficient osteoclasts demonstrate increased K310 NF-κB acetylation and NF-κB transcriptional activity. Hdac3-deficient osteoclast lineage cells were hyper-responsive to RANKL and showed elevated ex vivo osteoclast number and size and enhanced bone resorption in pit formation assays. Osteoclast-directed Hdac3 deficiency decreased cortical and trabecular bone mass parameters, suggesting that Hdac3 regulates coupling of bone resorption and bone formation. We surveyed a panel of osteoclast-derived coupling factors and found that Hdac3 suppression diminished sphingosine-1-phosphate production. Osteoclast-derived sphingosine-1-phosphate acts in paracrine to promote bone mineralization. Mineralization of WT bone marrow stromal cells cultured with conditioned medium from Hdac3-deficient osteoclasts was markedly reduced. Expression of alkaline phosphatase, type 1a1 collagen, and osteocalcin was also suppressed, but no change in Runx2 expression was observed. Our results demonstrate that Hdac3 controls bone modeling by suppressing osteoclast lineage cell responsiveness to RANKL and coupling to bone formation.
Collapse
Affiliation(s)
- David H H Molstad
- Department of Orthopedics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Anna M Mattson
- Departments of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Dana L Begun
- Departments of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Jennifer J Westendorf
- Departments of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA; Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Elizabeth W Bradley
- Department of Orthopedics, University of Minnesota, Minneapolis, Minnesota, USA; Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA.
| |
Collapse
|
3
|
Mathis NJ, Adaniya EN, Smith LM, Robling AG, Jepsen KJ, Schlecht SH. Differential changes in bone strength of two inbred mouse strains following administration of a sclerostin-neutralizing antibody during growth. PLoS One 2019; 14:e0214520. [PMID: 30947279 PMCID: PMC6448823 DOI: 10.1371/journal.pone.0214520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 03/14/2019] [Indexed: 12/02/2022] Open
Abstract
Administration of sclerostin-neutralizing antibody (Scl-Ab) treatment has been shown to elicit an anabolic bone response in growing and adult mice. Prior work characterized the response of individual mouse strains but did not establish whether the impact of Scl-Ab on whole bone strength would vary across different inbred mouse strains. Herein, we tested the hypothesis that two inbred mouse strains (A/J and C57BL/6J (B6)) will show different whole bone strength outcomes following sclerostin-neutralizing antibody (Scl-Ab) treatment during growth (4.5–8.5 weeks of age). Treated B6 femurs showed a significantly greater stiffness (S) (68.8% vs. 46.0%) and maximum load (ML) (84.7% vs. 44.8%) compared to A/J. Although treated A/J and B6 femurs showed greater cortical area (Ct.Ar) similarly relative to their controls (37.7% in A/J and 41.1% in B6), the location of new bone deposition responsible for the greater mass differed between strains and may explain the greater whole bone strength observed in treated B6 mice. A/J femurs showed periosteal expansion and endocortical infilling, while B6 femurs showed periosteal expansion. Post-yield displacement (PYD) was smaller in treated A/J femurs (-61.2%, p < 0.001) resulting in greater brittleness compared to controls; an effect not present in B6 mice. Inter-strain differences in S, ML, and PYD led to divergent changes in work-to-fracture (Work). Work was 27.2% (p = 0.366) lower in treated A/J mice and 66.2% (p < 0.001) greater in treated B6 mice relative to controls. Our data confirmed the anabolic response to Scl-Ab shown by others, and provided evidence suggesting the mechanical benefits of Scl-Ab administration may be modulated by genetic background, with intrinsic growth patterns of these mice guiding the location of new bone deposition. Whether these differential outcomes will persist in adult and elderly mice remains to be determined.
Collapse
Affiliation(s)
- Noah J. Mathis
- School of Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Emily N. Adaniya
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Lauren M. Smith
- School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alexander G. Robling
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Karl J. Jepsen
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Stephen H. Schlecht
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
4
|
Yuan J, Tickner J, Mullin BH, Zhao J, Zeng Z, Morahan G, Xu J. Advanced Genetic Approaches in Discovery and Characterization of Genes Involved With Osteoporosis in Mouse and Human. Front Genet 2019; 10:288. [PMID: 31001327 PMCID: PMC6455049 DOI: 10.3389/fgene.2019.00288] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 03/18/2019] [Indexed: 12/14/2022] Open
Abstract
Osteoporosis is a complex condition with contributions from, and interactions between, multiple genetic loci and environmental factors. This review summarizes key advances in the application of genetic approaches for the identification of osteoporosis susceptibility genes. Genome-wide linkage analysis (GWLA) is the classical approach for identification of genes that cause monogenic diseases; however, it has shown limited success for complex diseases like osteoporosis. In contrast, genome-wide association studies (GWAS) have successfully identified over 200 osteoporosis susceptibility loci with genome-wide significance, and have provided most of the candidate genes identified to date. Phenome-wide association studies (PheWAS) apply a phenotype-to-genotype approach which can be used to complement GWAS. PheWAS is capable of characterizing the association between osteoporosis and uncommon and rare genetic variants. Another alternative approach, whole genome sequencing (WGS), will enable the discovery of uncommon and rare genetic variants in osteoporosis. Meta-analysis with increasing statistical power can offer greater confidence in gene searching through the analysis of combined results across genetic studies. Recently, new approaches to gene discovery include animal phenotype based models such as the Collaborative Cross and ENU mutagenesis. Site-directed mutagenesis and genome editing tools such as CRISPR/Cas9, TALENs and ZNFs have been used in functional analysis of candidate genes in vitro and in vivo. These resources are revolutionizing the identification of osteoporosis susceptibility genes through the use of genetically defined inbred mouse libraries, which are screened for bone phenotypes that are then correlated with known genetic variation. Identification of osteoporosis-related susceptibility genes by genetic approaches enables further characterization of gene function in animal models, with the ultimate aim being the identification of novel therapeutic targets for osteoporosis.
Collapse
Affiliation(s)
- Jinbo Yuan
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Jennifer Tickner
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Benjamin H Mullin
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia.,Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - Jinmin Zhao
- Research Centre for Regenerative Medicine, Guangxi Medical University, Nanning, China
| | - Zhiyu Zeng
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Grant Morahan
- Centre for Diabetes Research, Harry Perkins Institute of Medical Research, The University of Western Australia, Perth, WA, Australia
| | - Jiake Xu
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
| |
Collapse
|
5
|
Schlecht SH, Ramcharan MA, Yang Y, Smith LM, Bigelow EM, Nolan BT, Moss DE, Devlin MJ, Jepsen KJ. Differential Adaptive Response of Growing Bones From Two Female Inbred Mouse Strains to Voluntary Cage-Wheel Running. JBMR Plus 2018; 2:143-153. [PMID: 30283899 PMCID: PMC6124195 DOI: 10.1002/jbm4.10032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/27/2017] [Accepted: 01/04/2018] [Indexed: 11/30/2022] Open
Abstract
The phenotypic response of bones differing in morphological, compositional, and mechanical traits to an increase in loading during growth is not well understood. We tested whether bones of two inbred mouse strains that assemble differing sets of traits to achieve mechanical homeostasis at adulthood would show divergent responses to voluntary cage‐wheel running. Female A/J and C57BL6/J (B6) 4‐week‐old mice were provided unrestricted access to a standard cage‐wheel for 4 weeks. A/J mice have narrow and highly mineralized femora and B6 mice have wide and less mineralized femora. Both strains averaged 2 to 9.5 km of running per day, with the average‐distance run between strains not significantly different (p = 0.133). Exercised A/J femora showed an anabolic response to exercise with the diaphyses showing a 2.8% greater total area (Tt.Ar, p = 0.06) and 4.7% greater cortical area (Ct.Ar, p = 0.012) compared to controls. In contrast, exercised B6 femora showed a 6.2% (p < 0.001) decrease in Tt.Ar (p < 0.001) and a 6.7% decrease in Ct.Ar (p = 0.133) compared to controls, with the femora showing significant marrow infilling (p = 0.002). These divergent morphological responses to exercise, which did not depend on the daily distance run, translated to a 7.9% (p = 0.001) higher maximum load (ML) for exercised A/J femora but no change in ML for exercised B6 femora compared to controls. A consistent response was observed for the humeri but not the vertebral bodies. This differential outcome to exercise has not been previously observed in isolated loading or forced treadmill running regimes. Our findings suggest there are critical factors involved in the metabolic response to exercise during growth that require further consideration to understand how genotype, exercise, bone morphology, and whole‐bone strength interact during growth. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Stephen H Schlecht
- Department of Orthopaedic Surgery University of Michigan Ann Arbor MI USA
| | | | | | - Lauren M Smith
- School of Public Health University of Michigan Ann Arbor MI USA
| | - Erin Mr Bigelow
- Department of Orthopaedic Surgery University of Michigan Ann Arbor MI USA
| | - Bonnie T Nolan
- Department of Orthopaedic Surgery University of Michigan Ann Arbor MI USA
| | - Drew E Moss
- Department of Orthopaedic Surgery University of Michigan Ann Arbor MI USA
| | - Maureen J Devlin
- Department of Anthropology University of Michigan Ann Arbor MI USA
| | - Karl J Jepsen
- Department of Orthopaedic Surgery University of Michigan Ann Arbor MI USA
| |
Collapse
|
6
|
Stephens NB, Kivell TL, Pahr DH, Hublin JJ, Skinner MM. Trabecular bone patterning across the human hand. J Hum Evol 2018; 123:1-23. [PMID: 30072187 DOI: 10.1016/j.jhevol.2018.05.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 05/09/2018] [Accepted: 05/10/2018] [Indexed: 02/06/2023]
Abstract
Hand bone morphology is regularly used to link particular hominin species with behaviors relevant to cognitive/technological progress. Debates about the functional significance of differing hominin hand bone morphologies tend to rely on establishing phylogenetic relationships and/or inferring behavior from epigenetic variation arising from mechanical loading and adaptive bone modeling. Most research focuses on variation in cortical bone structure, but additional information about hand function may be provided through the analysis of internal trabecular structure. While primate hand bone trabecular structure is known to vary in ways that are consistent with expected joint loading differences during manipulation and locomotion, no study exists that has documented this variation across the numerous bones of the hand. We quantify the trabecular structure in 22 bones of the human hand (early/extant modern Homo sapiens) and compare structural variation between two groups associated with post-agricultural/industrial (post-Neolithic) and foraging/hunter-gatherer (forager) subsistence strategies. We (1) establish trabecular bone volume fraction (BV/TV), modulus (E), degree of anisotropy (DA), mean trabecular thickness (Tb.Th) and spacing (Tb.Sp); (2) visualize the average distribution of site-specific BV/TV for each bone; and (3) examine if the variation in trabecular structure is consistent with expected joint loading differences among the regions of the hand and between the groups. Results indicate similar distributions of trabecular bone in both groups, with those of the forager sample presenting higher BV/TV, E, and lower DA, suggesting greater and more variable loading during manipulation. We find indications of higher loading along the ulnar side of the forager sample hand, with high site-specific BV/TV distributions among the carpals that are suggestive of high loading while the wrist moves through the 'dart-thrower's' motion. These results support the use of trabecular structure to infer behavior and have direct implications for refining our understanding of human hand evolution and fossil hominin hand use.
Collapse
Affiliation(s)
- Nicholas B Stephens
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany.
| | - Tracy L Kivell
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury CT2 7NZ, United Kingdom; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Dieter H Pahr
- Institute for Lightweight Design and Structural Biomechanics, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Matthew M Skinner
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury CT2 7NZ, United Kingdom; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| |
Collapse
|
7
|
Xin F, Smith LM, Susiarjo M, Bartolomei MS, Jepsen KJ. Endocrine-disrupting chemicals, epigenetics, and skeletal system dysfunction: exploration of links using bisphenol A as a model system. ENVIRONMENTAL EPIGENETICS 2018; 4:dvy002. [PMID: 29732168 PMCID: PMC5920333 DOI: 10.1093/eep/dvy002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/14/2018] [Accepted: 02/15/2018] [Indexed: 06/08/2023]
Abstract
Early life exposures to endocrine-disrupting chemicals (EDCs) have been associated with physiological changes of endocrine-sensitive tissues throughout postnatal life. Although hormones play a critical role in skeletal growth and maintenance, the effects of prenatal EDC exposure on adult bone health are not well understood. Moreover, studies assessing skeletal changes across multiple generations are limited. In this article, we present previously unpublished data demonstrating dose-, sex-, and generation-specific changes in bone morphology and function in adult mice developmentally exposed to the model estrogenic EDC bisphenol A (BPA) at doses of 10 μg (lower dose) or 10 mg per kg bw/d (upper dose) throughout gestation and lactation. We show that F1 generation adult males, but not females, developmentally exposed to bisphenol A exhibit dose-dependent reductions in outer bone size resulting in compromised bone stiffness and strength. These structural alterations and weaker bone phenotypes in the F1 generation did not persist in the F2 generation. Instead, F2 generation males exhibited greater bone strength. The underlying mechanisms driving the EDC-induced physiological changes remain to be determined. We discuss potential molecular changes that could contribute to the EDC-induced skeletal effects, with an emphasis on epigenetic dysregulation. Furthermore, we assess the necessity of intact sex steroid receptors to mediate these effects. Expanding future assessments of EDC-induced effects to the skeleton may provide much needed insight into one of the many health effects of these chemicals and aid in regulatory decision making regarding exposure of vulnerable populations to these chemicals.
Collapse
Affiliation(s)
- Frances Xin
- Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center of Excellence in Environmental Toxicology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lauren M Smith
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | - Martha Susiarjo
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY14642, USA
| | - Marisa S Bartolomei
- Epigenetics Institute, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center of Excellence in Environmental Toxicology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karl J Jepsen
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|
8
|
Whole bone testing in small animals: systematic characterization of the mechanical properties of different rodent bones available for rat fracture models. Eur J Med Res 2018; 23:8. [PMID: 29444703 PMCID: PMC5813325 DOI: 10.1186/s40001-018-0307-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/07/2018] [Indexed: 01/15/2023] Open
Abstract
Objectives Rat fracture models are extensively used to characterize normal and pathological bone healing. Despite, systematic research on inter- and intra-individual differences of common rat bones examined is surprisingly not available. Thus, we studied the biomechanical behaviour and radiological characteristics of the humerus, the tibia and the femur of the male Wistar rat—all of which are potentially available in the experimental situation—to identify useful or detrimental biomechanical properties of each bone and to facilitate sample size calculations. Methods 40 paired femura, tibiae and humeri of male Wistar rats (10–38 weeks, weight between 240 and 720 g) were analysed by DXA, pQCT scan and three-point-bending. Bearing and loading bars of the biomechanical setup were adapted percentually to the bone’s length. Subgroups of light (skeletal immature) rats under 400 g (N = 11, 22 specimens of each bone) and heavy (mature) rats over 400 g (N = 9, 18 specimens of each bone) were formed and evaluated separately. Results Radiologically, neither significant differences between left and right bones, nor a specific side preference was evident. Mean side differences of the BMC were relatively small (1–3% measured by DXA and 2.5–5% by pQCT). Over all, bone mineral content (BMC) assessed by DXA and pQCT (TOT CNT, CORT CNT) showed high correlations between each other (BMC vs. TOT and CORT CNT: R2 = 0.94–0.99). The load–displacement diagram showed a typical, reproducible curve for each type of bone. Tibiae were the longest bones (mean 41.8 ± 4.12 mm) followed by femurs (mean 38.9 ± 4.12 mm) and humeri (mean 29.88 ± 3.33 mm). Failure loads and stiffness ranged from 175.4 ± 45.23 N / 315.6 ± 63.00 N/mm for the femurs, 124.6 ± 41.13 N / 260.5 ± 59.97 N/mm for the humeri to 117.1 ± 33.94 N / 143.8 ± 36.99 N/mm for the tibiae. Smallest interindividual differences were observed in failure loads of the femurs (CV% 8.6) and tibiae (CV% 10.7) of heavy animals, light animals showed good consistency in failure loads of the humeri (CV% 7.7). Most consistent results of both sides (left vs. right) in failure loads were provided by the femurs of light animals (mean difference 4.0 ± 2.8%); concerning stiffness, humeri of heavy animals were most consistent (mean difference of 6.2 ± 5%). In general, the failure loads showed strong correlations to the BMC (R2 = 0.85–0.88) whereas stiffness correlated only moderate, except for the humerus (BMC vs. stiffness: R2 = 0.79). Discussion Altogether, the rat’s femur of mature specimens showed the most accurate and consistent radiological and biomechanical results. In synopsis with the common experimental use enabling comparison among different studies, this bone offers ideal biomechanical conditions for three point bending experiments. This can be explained by the combination of a superior aspect ratio and a round and long, straight morphology, which satisfies the beam criteria more than other bones tested. Electronic supplementary material The online version of this article (10.1186/s40001-018-0307-z) contains supplementary material, which is available to authorized users.
Collapse
|
9
|
Schlecht SH, Smith LM, Ramcharan MA, Bigelow EM, Nolan BT, Mathis NJ, Cathey A, Manley E, Menon R, McEachin RC, Nadeau JH, Jepsen KJ. Canalization Leads to Similar Whole Bone Mechanical Function at Maturity in Two Inbred Strains of Mice. J Bone Miner Res 2017; 32:1002-1013. [PMID: 28177139 PMCID: PMC5413428 DOI: 10.1002/jbmr.3093] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 01/19/2017] [Accepted: 02/01/2017] [Indexed: 11/10/2022]
Abstract
Previously, we showed that cortical mineralization is coordinately adjusted to mechanically offset external bone size differences between A/J (narrow) and C57BL/6J (wide) mouse femora to achieve whole bone strength equivalence at adulthood. The identity of the genes and their interactions that are responsible for establishing this homeostatic state (ie, canalization) remain unknown. We hypothesize that these inbred strains, whose interindividual differences in bone structure and material properties mimic that observed among humans, achieve functional homeostasis by differentially adjusting key molecular pathways regulating external bone size and mineralization throughout growth. The cortices of A/J and C57BL/6J male mouse femora were phenotyped and gene expression levels were assessed across growth (ie, ages 2, 4, 6, 8, 12, 16 weeks). A difference in total cross-sectional area (p < 0.01) and cortical tissue mineral density were apparent between mouse strains by age 2 weeks and maintained at adulthood (p < 0.01). These phenotypic dissimilarities corresponded to gene expression level differences among key regulatory pathways throughout growth. A/J mice had a 1.55- to 7.65-fold greater expression among genes inhibitory to Wnt pathway induction, whereas genes involved in cortical mineralization were largely upregulated 1.50- to 3.77-fold to compensate for their narrow diaphysis. Additionally, both mouse strains showed an upregulation among Wnt pathway antagonists corresponding to the onset of adult ambulation (ie, increased physiological loads). This contrasts with other studies showing an increase in Wnt pathway activation after functionally isolated, experimental in vivo loading regimens. A/J and C57BL/6J long bones provide a model to develop a systems-based approach to identify individual genes and the gene-gene interactions that contribute to trait differences between the strains while being involved in the process by which these traits are coordinately adjusted to establish similar levels of mechanical function, thus providing insight into the process of canalization. © 2017 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Stephen H Schlecht
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Lauren M Smith
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Melissa A Ramcharan
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Erin Mr Bigelow
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Bonnie T Nolan
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Noah J Mathis
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Amber Cathey
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Eugene Manley
- Department of Cell, Developmental, and Cancer Biology, Oregon Health and Science University, Portland, OR, USA
| | - Rajasree Menon
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Richard C McEachin
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Joseph H Nadeau
- Pacific Northwest Diabetes Research Institute, Seattle, WA, USA
| | - Karl J Jepsen
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
10
|
Raygorodskaya M, Gabet Y, Shochat C, Kobyliansky E, Torchinsky A, Karasik D. Intrauterine stress induces bone loss in adult offspring of C3H/HeJ mice having high bone mass phenotype but not C57BL/6J mice with low bone mass phenotype. Bone 2016; 87:114-9. [PMID: 27072519 DOI: 10.1016/j.bone.2016.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 01/22/2023]
Abstract
In this study we examined to what extent and how genetics may modify osteoporosis risk arising due to environmental stresses which act during the antenatal period of life and have the potential to induce bone loss in adulthood. C57Bl/6J (C57) and C3H/HeJ (C3H) mice were used as a model system. The mice were exposed to a single injection of 5-aza-2'-deoxycytidine (5-AZA) on day 10 of pregnancy and the structure and bone mineral density (BMD) of the femur and 3rd lumbar vertebra of 3- and 6-month-old male and female offspring were evaluated by micro-computed tomography (μCT). Besides, we also attempted to evaluate whether 5-AZA affects the expression of some osteogenic genes in the embryonic limb buds. The main observation of this study is that 5-AZA-induced loss of bone quality was registered in 6-mo-old C3H offspring but not in their C57 counterparts. We also observed that C57 and C3H embryos may differ in their response to 5-AZA-induced detrimental stimuli: whereas 5-AZA treated C3H embryos exhibited a decreased expression of Col1a1, C57 embryos exhibit a decreased expression of Sox9. Overall, our study, by thorough characterization of bone homeostasis in 3- and 6-month-old offspring of 5-AZA-exposed C57 and C3H mice, allows hypothesizing that the adaptive response to antenatal insults may be stronger in offspring inherently exhibiting a low bone mass phenotype than in offspring inherently exhibiting a high bone mass phenotype.
Collapse
Affiliation(s)
- M Raygorodskaya
- Faculty of Medicine in the Galilee, Bar Ilan University, Safed, Israel
| | - Y Gabet
- Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - C Shochat
- Faculty of Medicine in the Galilee, Bar Ilan University, Safed, Israel
| | - E Kobyliansky
- Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - A Torchinsky
- Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - D Karasik
- Faculty of Medicine in the Galilee, Bar Ilan University, Safed, Israel.
| |
Collapse
|
11
|
Kristianto J, Litscher SJ, Johnson MG, Patel F, Patel M, Fisher J, Zastrow RK, Radcliff AB, Blank RD. Congenic Strains Confirm the Pleiotropic Effect of Chromosome 4 QTL on Mouse Femoral Geometry and Biomechanical Performance. PLoS One 2016; 11:e0148571. [PMID: 26849124 PMCID: PMC4743951 DOI: 10.1371/journal.pone.0148571] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/19/2016] [Indexed: 11/19/2022] Open
Abstract
A pleiotropic quantitative trait locus (QTL) for bone geometry and mechanical performance in mice was mapped to distal chromosome 4 via an intercross of recombinant congenic mice HcB-8 and HcB-23. To study the QTL in isolation, we have generated C3H.B10-(rs6355453-rs13478087) (C.B.4.3) and C3H.B10-(rs6369860-D4Mit170) (C.B.4.2) congenic strains that harbor ~20 Mb and ~3 Mb, respectively, of chromosome 4 overlapping segments from C57BL/10ScSnA (B10) within the locus on a C3H/DiSnA (C3H) background. Using 3-point bend testing and standard beam equations, we phenotyped these mice for femoral mid-diaphyseal geometry and biomechanical performance. We analyzed the results via 2-way ANOVA, using sex and genotype as factors. In the C.B.4.3 strain, we found that homozygous B10/B10 male mice had smaller cross sectional area (CSA) and reduced total displacement than homozygous C3H/C3H mice. Sex by genotype interaction was also observed for maximum load and stiffness for C3H/C3H and B10/B10 mice, respectively. In C.B.4.2 strain, we found that homozygous B10/B10 mice had lower total displacement, post-yield displacement (PYD), stiffness, yield load and maximum load than mice harboring C3H allele. Sex by genotype interaction was observed in B10/B10 mice for perimeter, outer minor axis (OMA) and CSA. There were no significant differences in tissue level mechanical performance, which suggest that the QTL acts primarily on circumferential bone size. These data confirm the prior QTL mapping data and support other work demonstrating the importance of chromosome 4 QTL on bone modeling and bone responses to mechanical loading.
Collapse
Affiliation(s)
- Jasmin Kristianto
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
| | - Suzanne J. Litscher
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Michael G. Johnson
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Forum Patel
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Mital Patel
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jacqueline Fisher
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ryley K. Zastrow
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Abigail B. Radcliff
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Robert D. Blank
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin, United States of America
- Milwaukee VA Medical Center, Milwaukee, Wisconsin, United States of America
| |
Collapse
|
12
|
Wagermaier W, Klaushofer K, Fratzl P. Fragility of Bone Material Controlled by Internal Interfaces. Calcif Tissue Int 2015; 97:201-12. [PMID: 25772807 PMCID: PMC4525333 DOI: 10.1007/s00223-015-9978-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 02/28/2015] [Indexed: 12/14/2022]
Abstract
Bone material is built in a complex multiscale arrangement of mineralized collagen fibrils containing water, proteoglycans and some noncollagenous proteins. This organization is not static as bone is constantly remodeled and thus able to repair damaged tissue and adapt to the loading situation. In preventing fractures, the most important mechanical property is toughness, which is the ability to absorb impact energy without reaching complete failure. There is no simple explanation for the origin of the toughness of bone material, and this property depends in a complex way on the internal architecture of the material on all scales from nanometers to millimeters. Hence, fragility may have different mechanical origins, depending on which toughening mechanism is not working properly. This article reviews the toughening mechanisms described for bone material and attempts to put them in a clinical context, with the hope that future analysis of bone fragility may be guided by this collection of possible mechanistic origins.
Collapse
Affiliation(s)
- Wolfgang Wagermaier
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany
| | - Klaus Klaushofer
- First Medical Department, Hanusch Hospital, Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, Heinrich Collin Str. 30, 1140 Vienna, Austria
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany
| |
Collapse
|
13
|
Jepsen KJ, Silva MJ, Vashishth D, Guo XE, van der Meulen MCH. Establishing biomechanical mechanisms in mouse models: practical guidelines for systematically evaluating phenotypic changes in the diaphyses of long bones. J Bone Miner Res 2015; 30:951-66. [PMID: 25917136 PMCID: PMC4794979 DOI: 10.1002/jbmr.2539] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/03/2015] [Accepted: 04/21/2015] [Indexed: 12/30/2022]
Abstract
Mice are widely used in studies of skeletal biology, and assessment of their bones by mechanical testing is a critical step when evaluating the functional effects of an experimental perturbation. For example, a gene knockout may target a pathway important in bone formation and result in a "low bone mass" phenotype. But how well does the skeleton bear functional loads; eg, how much do bones deform during loading and how resistant are bones to fracture? By systematic evaluation of bone morphological, densitometric, and mechanical properties, investigators can establish the "biomechanical mechanisms" whereby an experimental perturbation alters whole-bone mechanical function. The goal of this review is to clarify these biomechanical mechanisms and to make recommendations for systematically evaluating phenotypic changes in mouse bones, with a focus on long-bone diaphyses and cortical bone. Further, minimum reportable standards for testing conditions and outcome variables are suggested that will improve the comparison of data across studies. Basic biomechanical principles are reviewed, followed by a description of the cross-sectional morphological properties that best inform the net cellular effects of a given experimental perturbation and are most relevant to biomechanical function. Although morphology is critical, whole-bone mechanical properties can only be determined accurately by a mechanical test. The functional importance of stiffness, maximum load, postyield displacement, and work-to-fracture are reviewed. Because bone and body size are often strongly related, strategies to adjust whole-bone properties for body mass are detailed. Finally, a comprehensive framework is presented using real data, and several examples from the literature are reviewed to illustrate how to synthesize morphological, tissue-level, and whole-bone mechanical properties of mouse long bones.
Collapse
Affiliation(s)
- Karl J Jepsen
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Matthew J Silva
- Department of Orthopaedic Surgery, Washington University, St. Louis, MO, USA
| | - Deepak Vashishth
- Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - X Edward Guo
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Marjolein CH van der Meulen
- Department of Biomedical Engineering and Sibley School of Mechanical & Aerospace Engineering, Cornell University, Ithaca, NY, USA
| |
Collapse
|
14
|
Blank RD. System level genes or physiological adaptation? Bone 2015; 75:247-8. [PMID: 25073030 PMCID: PMC4617642 DOI: 10.1016/j.bone.2014.07.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 07/21/2014] [Indexed: 11/17/2022]
Affiliation(s)
- Robert D Blank
- Clement J Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA; Medical College of Wisconsin, Milwaukee, WI, USA.
| |
Collapse
|