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Rooney AM, McNeill TJ, Ross FP, Bostrom MPG, van der Meulen MCH. PTH Treatment Increases Cortical Bone Mass More in Response to Compression than Tension in Mice. J Bone Miner Res 2023; 38:59-69. [PMID: 36281491 DOI: 10.1002/jbmr.4728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 10/08/2022] [Accepted: 10/19/2022] [Indexed: 01/10/2023]
Abstract
Parathyroid hormone (PTH) is an anabolic osteoporosis treatment that increases bone mass and reduces fracture risk. Clinically, the effects of PTH are site-specific, increasing bone mass more at the spine than the hip and not increasing bone mass at the radius. Differences in local loading environment between the spine, hip, and radius may help explain the variation in efficacy, as PTH and mechanical loading have been shown to synergistically increase bone mass. We hypothesized that differences in loading mode might further explain these variations. Owing to the curvature of the mouse tibia, cyclic compression of the hindlimb causes bending at the tibial midshaft, placing the anterior surface under tension and the posterior surface under compression. We investigated the combination of PTH treatment and tibial loading in an osteoblast-specific estrogen receptor-alpha knockout mouse model of low bone mass (pOC-ERαKO) and their littermate controls (LCs) and analyzed bone morphology in the tensile, compressive, and neutral regions of the tibial midshaft. We also hypothesized that pretreating wild-type C57Bl/6J (WT) mice with PTH prior to mechanical loading would enhance the synergistic anabolic effects. Compression was more anabolic than tension, and PTH enhanced the effect of loading, particularly under compression. PTH pretreatment maintained the synergistic anabolic effect for longer durations than concurrent treatment and loading alone. Together these data provide insights into more effective physical therapy and exercise regimens for patients receiving PTH treatment. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Amanda M Rooney
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Tyler J McNeill
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | | | | | - Marjolein C H van der Meulen
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
- Research Division, Hospital for Special Surgery, New York, New York, USA
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Speacht TL, Lang CH, Donahue HJ. Soluble RANKL exaggerates hindlimb suspension-induced osteopenia but not muscle protein balance. J Orthop Res 2021; 39:1860-1869. [PMID: 33222219 PMCID: PMC8140066 DOI: 10.1002/jor.24917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/02/2020] [Accepted: 11/19/2020] [Indexed: 02/04/2023]
Abstract
We examined the hypothesis that exaggerating unloading-induced bone loss using a combination of hindlimb suspension (HLS) and exogenous injections of receptor activator of nuclear factor-κB ligand (RANKL) also exaggerates gastrocnemius and quadriceps muscle loss. Forty, male C57Bl/6J mice (16 weeks) were subjected to HLS or normal ambulation (ground control, GC) for 14 days. Mice received three intraperitoneal injections of either human recombinant soluble RANKL or phosphate-buffered saline as control (n = 10/group) at 24 h intervals starting on Day 1 of HLS. GC + RANKL and HLS mice exhibited similar decreases in trabecular bone volume and density in both proximal tibias and distal femurs. However, RANKL affected trabecular number, separation, and connectivity density, while HLS decreased trabecular thickness. The combination of RANKL and HLS exacerbated these changes. Similarly, GC + RANKL and HLS mice saw comparable decreases in cortical bone volume, thickness, and strength in femur midshafts, and combination treatment exacerbated these changes. Plasma concentrations of P1NP were increased in both groups receiving RANKL, while CTX concentrations were unchanged. HLS decreased gastrocnemius weight and was associated with a reduction in global protein synthesis, and no change in proteasome activity. This change was correlated with a decrease in S6K1 and S6 phosphorylation, but no change in 4E-BP1 phosphorylation. Injection of RANKL did not alter gastrocnemius or quadriceps muscle protein metabolism in GC or HLS mice. Our results suggest that injection of soluble RANKL exacerbates unloading-induced bone loss, but not unloading-induced gastrocnemius or quadriceps muscle loss.
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Affiliation(s)
- Toni L. Speacht
- Department of Orthopaedics and Rehabilitation, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, USA
| | - Charles H. Lang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, USA
| | - Henry J. Donahue
- Department of Orthopaedics and Rehabilitation, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, USA,Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
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Mantri AV, Allaway HCM, Brezicha JE, Hogan HA, Bloomfield SA. Oral Estradiol Impact on Mitigating Unloading-Induced Bone Loss in Ovary-Intact Rats. Aerosp Med Hum Perform 2021; 92:65-74. [PMID: 33468286 DOI: 10.3357/amhp.5668.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND: The impact of the spaceflight environment on endogenous estrogen production in female crewmembers and the resulting impact on other adaptations, like bone loss, is an under-investigated topic. Hence, we investigated the interaction of exogenous 17- estradiol (E2) treatment and disuse to test the hypothesis that E2 treatment would mitigate disuse-induced bone loss.METHODS: There were 40 virgin female Sprague-Dawley rats (5 mo old) randomized to placebo (PL; 0 ppm E2) or estrogen (E2; 10 ppm E2) treatments, delivered via custom-made rodent diets; half of each group was randomized to either weightbearing (WB) or hindlimb unloading (HU) for 39 d.RESULTS: We observed expected lower values after HU (615%) in volumetric BMD and cross-sectional areas at the proximal tibia metaphysis (PTM, by pQCT), 20% lower %BV/TV (nonsignificant) at the PTM, and 11% lower femoral neck maximal load; none of these HU-induced impacts were modified by E2. Impaired PTM periosteal expansion was observed in all E2-treated rats, with smaller (13 to 18%) cross-sectional areas. Midshaft tibial geometry was unaffected by E2 treatment, but large reductions (73 to 81%) in periosteal bone formation indices were observed in E2-treated rats.DISCUSSION: In summary, modest supplementation of exogenous E2 did not mitigate decrements in volumetric BMD, PTM cross-sectional geometry, or femoral neck strength observed with HU. However, numerous independent impacts of E2 treatment were observed, with significant suppression of periosteal bone formation indices. If maintained over time, this might impact negatively on cortical bone integrity during prolonged nonweightbearing.Mantri AV, Allaway HCM, Brezicha JE, Hogan HA, Bloomfield SA. Oral estradiol impact on mitigating unloading-induced bone loss in ovary-intact rats. Aerosp Med Hum Perform. 2021; 92(2):6574.
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Zhang D, Miranda M, Li X, Han J, Sun Y, Rojas N, He S, Hu M, Lin L, Li X, Ke HZ, Qin YX. Retention of osteocytic micromorphology by sclerostin antibody in a concurrent ovariectomy and functional disuse model. Ann N Y Acad Sci 2019; 1442:91-103. [PMID: 30644553 PMCID: PMC6465143 DOI: 10.1111/nyas.13991] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 09/20/2018] [Accepted: 10/26/2018] [Indexed: 12/26/2022]
Abstract
Prolonged mechanical unloading in bedridden patients and concurrent hormonal dysregulation represents the cause of one of the severest forms of osteoporosis, a condition for which there are very few efficacious interventions available to date. Sclerostin, a Wnt antagonist, acts as a negative regulator of bone formation. Sclerostin antibody (Scl-Ab)-mediated blockade of sclerostin can dramatically enhance bone formation and reduce bone resorption. This study was designed to investigate the therapeutic effect of the Scl-Ab on severe bone loss induced by concurrent mechanical unloading and estrogen deficiency in a hindlimb-suspended and ovariectomized rat model, and to study the cellular mechanisms underlying severe osteoporosis and Scl-Ab action. Unloading and ovariectomy resulted in severe loss of trabecular and cortical bone mass and strength; Scl-Ab can significantly counteract the deterioration of bone in unloaded and/or ovariectomized rats, with noticeably increased cortical bone formation. Scanning electron microscopy analysis revealed that unloading and ovariectomy lead to multiple morphological and structural abnormalities of osteocytes in cortical bone and the abnormalities were abolished by Scl-Ab administration. This study extends our previous conclusion that Scl-Ab represents a promising therapeutic approach for severe bone loss that occurs after being exposed to estrogen deficiency and prolonged mechanical unloading.
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Affiliation(s)
- Dongye Zhang
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Marianna Miranda
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Xiaofei Li
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Jiangmeng Han
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Yueli Sun
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Nancy Rojas
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Shan He
- Dept. of Material Science Engineering, Stony Brook University, Stony Brook, NY
| | - Minyi Hu
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Liangjun Lin
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
| | - Xiaodong Li
- Dept. of Metabolic Disorders, Amgen, Inc., Thousand Oaks, CA
| | | | - Yi-Xian Qin
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY
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Potential of electrical impedance spectroscopy to differentiate between healthy and osteopenic bone. Clin Biomech (Bristol, Avon) 2018; 57:81-88. [PMID: 29960118 DOI: 10.1016/j.clinbiomech.2018.05.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 05/25/2018] [Accepted: 05/25/2018] [Indexed: 02/06/2023]
Abstract
UNLABELLED Osteoporosis involves loss of structural stability of bone due to an increase in bone porosity. Dual energy X-ray absorptometry is used to evaluate bone in terms of quantity. However, it does not give an evaluation of the patient's bone quality. For this, present study has been carried out to assess the structural deterioration of bone using electrical impedance spectroscopy. METHODS Electrical Impedance Spectroscopy has been applied to evaluate the structural and compositional changes of cortical bone in the frequency range of 50 Hz to 5 MHz for the ovariectomized rat model. Initially, bone resorption in the ovariectomized group has been confirmed by estimating tartaric resistant acid phosphatase levels; morphometric parameters; bone matrix components, hydroxyapatite crystallite size and bone micro architecture. The mid diaphyseal regions from the femora and tibiae of sixty days post ovariectomy and control rats were used for the measurement of dielectric parameters. A dispersion model based analysis has been developed by a complex least square fitting of the dielectric data. FINDINGS Increased tartaric resistant acid phosphatase levels, altered bone matrix components, hydroxyapatite crystallite size and disturbed microarchitecture in the ovariectomized group give us the confirmation of increased bone resorption following estrogen deficiency. These changes were shown to be reflected by single dispersion model based fitted parameters which shows the considerable change in all the parameters of ovariectomized group compared to the control. INTERPRETATION It has been demonstrated that the parameters of the dispersion model can reflect the bone structural and compositional changes.
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Rooney AM, van der Meulen MCH. Mouse models to evaluate the role of estrogen receptor α in skeletal maintenance and adaptation. Ann N Y Acad Sci 2017; 1410:85-92. [PMID: 29148577 DOI: 10.1111/nyas.13523] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 12/15/2022]
Abstract
Estrogen signaling and mechanical loading have individual and combined effects on skeletal maintenance and adaptation. Previous work investigating estrogen signaling both in vitro and in vivo using global estrogen receptor α (ERα) gene knockout mouse models has provided information regarding the role of ERα in regulating bone mass and adaptation to mechanical stimulation. However, these models have inherent limitations that confound interpretation of the data. Therefore, recent studies have focused on mice with targeted deletion of ERα from specific bone cells and their precursors. Cell stage, tissue type, and mouse sex all influence the effects of ERα gene deletion. Lack of ERα in osteoblast progenitor and precursor cells generally affects the periosteum of female and male mice. The absence of ERα in differentiated osteoblasts, osteocytes, and osteoclasts in mice generally resulted in reduced cancellous bone mass, with differing reports of the effect by animal sex and greater deficiencies in bone mass typically occurring in cancellous bone in female mice. Limited data exist for the role of bone cell-specific ERα in skeletal adaptation in vivo. Cell-specific ERα gene knockout mice provide an excellent platform for investigating the function of ERα in regulating skeletal phenotype and response to mechanical loading by sex and age.
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Affiliation(s)
- Amanda M Rooney
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York
| | - Marjolein C H van der Meulen
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York.,Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York.,Research Division, Hospital for Special Surgery, New York, New York
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Zhang Z, Ren H, Shen G, Qiu T, Liang D, Yang Z, Yao Z, Tang J, Jiang X, Wei Q. Animal models for glucocorticoid-induced postmenopausal osteoporosis: An updated review. Biomed Pharmacother 2016; 84:438-446. [PMID: 27685786 DOI: 10.1016/j.biopha.2016.09.045] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 08/21/2016] [Accepted: 09/12/2016] [Indexed: 12/27/2022] Open
Abstract
Glucocorticoid-induced postmenopausal osteoporosis is a severe osteoporosis, with high risk of major osteoporotic fractures. This severe osteoporosis urges more extensive and deeper basic study, in which suitable animal models are indispensable. However, no relevant review is available introducing this model systematically. Based on the recent studies on GI-PMOP, this brief review introduces the GI-PMOP animal model in terms of its establishment, evaluation of bone mass and discuss its molecular mechanism. Rat, rabbit and sheep with their respective merits were chosen. Both direct and indirect evaluation of bone mass help to understand the bone metabolism under different intervention. The crucial signaling pathways, miRNAs, osteogenic- or adipogenic- related factors and estrogen level may be the predominant contributors to the development of glucocorticoid-induced postmenopausal osteoporosis.
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Affiliation(s)
- Zhida Zhang
- The First School of Clinic Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
| | - Hui Ren
- The First School of Clinic Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
| | - Gengyang Shen
- The First School of Clinic Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Ting Qiu
- The First School of Clinic Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - De Liang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Zhidong Yang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Zhensong Yao
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Jingjing Tang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Xiaobing Jiang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China; Laboratory Affiliated to National Key Discipline of Orthopaedic and Traumatology of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
| | - Qiushi Wei
- The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
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Zhang D, Hu M, Chu T, Lin L, Wang J, Li X, Ke HZ, Qin YX. Sclerostin antibody prevented progressive bone loss in combined ovariectomized and concurrent functional disuse. Bone 2016; 87:161-8. [PMID: 26868528 PMCID: PMC4862887 DOI: 10.1016/j.bone.2016.02.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/16/2022]
Abstract
Osteoporosis is characterized by low bone mass and compromised trabecular architecture, and is commonly occurred in post-menopausal women with estrogen deficiency. In addition, prolonged mechanical unloading, i.e., long term bed rest, can exaggerate the bone loss. Sclerostin is a Wnt signaling antagonist and acts as a negative regulator for bone formation. A sclerostin-neutralizing antibody (Scl-Ab) increased bone mineral density in women with postmenopausal osteoporosis and healthy men. The objective of this study was to characterize the condition of bone loss in ovariectomized (OVX) rats with concurrent mechanical unloading and evaluate the effect of sclerostin antibody treatment in mitigating the prospective severe bone loss conditions in this model. Four-month-old OVX- or sham-operated female SD rats were used in this study. They were subjected to functional disuse induced by hind-limb suspension (HLS) or free ambulance after 2days of arrival. Subcutaneous injections with either vehicle or Scl-Ab at 25mg/kg were made twice per week for 5weeks from the time of HLS. μCT analyses demonstrated a significant decrease in distal metaphyseal trabecular architecture integrity with HLS, OVX and HLS+OVX (bone volume fraction decreased by 29%, 71% and 87% respectively). The significant improvements of various trabecular bone parameters (bone volume fraction increased by 111%, 229% and 297% respectively as compared with placebo group) with the administration of Scl-Ab are associated with stronger mechanical property and increased bone formation by histomorphometry. These results together indicate that Scl-Ab prevented the loss of trabecular bone mass and cortical bone strength in OVX rat model with concurrent mechanical unloading. The data suggested that monoclonal sclerostin-neutralizing antibody represents a promising therapeutic approach for severe osteoporosis induced by estrogen deficiency with concurrent mechanical unloading.
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Affiliation(s)
- Dongye Zhang
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - Minyi Hu
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - Timothy Chu
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - Liangjun Lin
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - Jingyu Wang
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - Xiaodong Li
- Dept. of Metabolic Disorders, Amgen, Inc., Thousand Oaks, CA, United States
| | | | - Yi-Xian Qin
- Dept. of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States.
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Swimming Activity Prevents the Unloading Induced Loss of Bone Mass, Architecture, and Strength in Rats. BIOMED RESEARCH INTERNATIONAL 2015; 2015:507848. [PMID: 26090414 PMCID: PMC4450217 DOI: 10.1155/2015/507848] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 04/07/2015] [Accepted: 04/22/2015] [Indexed: 11/17/2022]
Abstract
We investigated whether swimming activity associated with a three-week period of hypoactivity could prevent the deleterious effects of disuse on the tibias of tail-suspended rats. Forty Wistar rats were divided into five groups: (HS) permanently hindlimb suspension rats; (HS + Swim) rats submitted to unloading interrupted by swimming exercise; (HS + WB) hindlimb suspension rats with interruption for regular weight bearing for the same length of time as the HS+Swim rats; (Control) control rats that were allowed regular cage activities; and (Control + Swim) control rats that underwent swimming exercise. At the end of the experiment, bone mineral density, bone strength, and trabecular quantification were analyzed. The hindlimb-suspended rats exhibited bone quality loss (significant decrease in BMD, bone strength, and deterioration of trabecular and cortical bone architecture; decrease in BV/TV, TbN, TbTh, ConnD, CtV, and CtTh; and increase in TbSp) when compared to control rats. In contrast, trained rats showed a significant increase of 43% in bone mass, 29% in bone strength, 58% in trabecular thickness, 85% in bone volume, 27% in trabeculae number, and 30% in cortical volume, when compared to the hindlimb-suspended rats. We conclude that swimming activity not only ameliorates but also fully prevents the deleterious effects on bone quality in osteopenic rats.
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Sun X, Liang J, Wang C, Cao S, Hu Y, Xu X. Transient Effect of 17β-estradiol on Osteoporosis in Ovariectomized Rats Accompanied with Unilateral Disuse in the Early Phase. Int J Med Sci 2015; 12:423-31. [PMID: 26078702 PMCID: PMC4466404 DOI: 10.7150/ijms.11887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/13/2015] [Indexed: 12/02/2022] Open
Abstract
PURPOSE It is clinically important to determine the efficacy of estrogen replacement for postmenopausal women combined with mobility difficulties, due to the potential risks of estradiol. The objective of the current study was to investigate the effect of estradiol replacement on osteoporosis induced by the ovariectomy (OVX) combined with unilateral sciatic neurectomy (SN) in a rat model. METHOD Female Sprague-Dawley rats were subjected to OVX and unilateral SN on the right hindlimb (OVX+SN) or sham surgery (CTRL). 17β-estradiol (E2) or vehicle was administrated to the rats immediately, and followed by every other day. Bone mass and trabecular microarchitecture were analyzed using micro-Computed Tomography (micro-CT) and histology at days 3, 7, 14, and 28 post-surgery. The local expressions of sclerostin/SOST, secreted exclusively by osteocytes, and tartrate-resistant acid phosphatase 5b (TRAP 5b), produced mostly by osteoclasts, were examined by immunohistochemistry and TRAP staining, respectively. Serum markers of bone resorption, including C-terminal telopeptides of type I collagen (CTx), receptor activator for nuclear factor κB ligand (RANKL), and TRAP 5b, were quantified by enzyme linked immunosorbent assay (ELISA). RESULT Based on micro-CT analysis, E2 treatment of OVX+SN rats improved the preservation of the bone volume fraction (BV/TV) and trabecular number (Tb.N) in the tibias at day 14 post-surgery, which were 43% and 46% higher in OVX+SN+E2 rats than those in OVX+SN rats, respectively. However, the impact of E2 was transient and disappeared at day 28. Expression of sclerostin in the tibias of OVX+SN rats was significantly elevated at day 7 post-surgery compared with the CTRL, but was suppressed until day 14 with E2 replacement. CONCLUSION Our results showed that estrogen replacement could transiently protect against bone loss in OVX rats combined with mechanical unloading. The up-regulation of sclerostin expression appears to be transiently delayed by E2 treatment in our models.
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Affiliation(s)
- Xiaodi Sun
- 1. School of Stomatology, Shandong University, Wenhuaxi Road 44-1, Jinan 250012, China. ; 3. Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan, China
| | - Jin Liang
- 1. School of Stomatology, Shandong University, Wenhuaxi Road 44-1, Jinan 250012, China. ; 3. Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan, China
| | - Chune Wang
- 2. Institute of Dental Medicine, Qilu Hospital, Shandong University, Wenhuaxi Road 107, Jinan 250012, China
| | - Sensen Cao
- 2. Institute of Dental Medicine, Qilu Hospital, Shandong University, Wenhuaxi Road 107, Jinan 250012, China
| | - Yingwei Hu
- 2. Institute of Dental Medicine, Qilu Hospital, Shandong University, Wenhuaxi Road 107, Jinan 250012, China
| | - Xin Xu
- 1. School of Stomatology, Shandong University, Wenhuaxi Road 44-1, Jinan 250012, China. ; 3. Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan, China
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Kondoh S, Inoue K, Igarashi K, Sugizaki H, Shirode-Fukuda Y, Inoue E, Yu T, Takeuchi JK, Kanno J, Bonewald LF, Imai Y. Estrogen receptor α in osteocytes regulates trabecular bone formation in female mice. Bone 2014; 60:68-77. [PMID: 24333171 PMCID: PMC3944732 DOI: 10.1016/j.bone.2013.12.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 11/26/2013] [Accepted: 12/04/2013] [Indexed: 11/17/2022]
Abstract
Estrogens are well known steroid hormones necessary to maintain bone health. In addition, mechanical loading, in which estrogen signaling may intersect with the Wnt/β-catenin pathway, is essential for bone maintenance. As osteocytes are known as the major mechanosensory cells embedded in mineralized bone matrix, osteocyte ERα deletion mice (ERα(ΔOcy/ΔOcy)) were generated by mating ERα floxed mice with Dmp1-Cre mice to determine the role of ERα in osteocytes. Trabecular bone mineral density of female, but not male ERα(ΔOcy/ΔOcy) mice was significantly decreased. Bone formation parameters in ERα(ΔOcy/ΔOcy) were significantly decreased while osteoclast parameters were unchanged. This suggests that ERα in osteocytes exerts osteoprotective function by positively controlling bone formation. To identify potential targets of ERα, gene array analysis of Dmp1-GFP osteocytes sorted by FACS from ERα(ΔOcy/ΔOcy) and control mice was performed. Gene expression microarray followed by gene ontology analyses revealed that osteocytes from ERα(ΔOcy/ΔOcy) highly expressed genes categorized in 'Secreted' when compared to control osteocytes. Among them, expression of Mdk and Sostdc1, both of which are Wnt inhibitors, was significantly increased without alteration of expression of the mature osteocyte markers such as Sost and β-catenin. Moreover, hindlimb suspension experiments showed that trabecular bone loss due to unloading was greater in ERα(ΔOcy/ΔOcy) mice without cortical bone loss. These data suggest that ERα in osteocytes has osteoprotective functions in trabecular bone formation through regulating expression of Wnt antagonists, but conversely plays a negative role in cortical bone loss due to unloading.
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Affiliation(s)
- Shino Kondoh
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Kazuki Inoue
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan; Division of Integrative Pathophysiology, Proteo-Science Center, Graduate School of Medicine, Ehime University, Ehime, Japan; Department of Biological Resources, Integrated Center for Science, Ehime University, Ehime, Japan
| | - Katsuhide Igarashi
- Division of Cellular & Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, Tokyo, Japan
| | - Hiroe Sugizaki
- Division of Cardiovascular Regeneration, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Yuko Shirode-Fukuda
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Erina Inoue
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Taiyong Yu
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan; Division of Integrative Pathophysiology, Proteo-Science Center, Graduate School of Medicine, Ehime University, Ehime, Japan
| | - Jun K Takeuchi
- Division of Cardiovascular Regeneration, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan; JST PRESTO, Japan
| | - Jun Kanno
- Division of Cellular & Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, Tokyo, Japan
| | - Lynda F Bonewald
- Department of Oral Biology, School of Dentistry, University of Missouri at Kansas City, Kansas City, MO, USA
| | - Yuuki Imai
- Laboratory of Epigenetic Skeletal Diseases, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan; Division of Integrative Pathophysiology, Proteo-Science Center, Graduate School of Medicine, Ehime University, Ehime, Japan.
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A rehabilitation exercise program induces severe bone mineral deficits in estrogen-deficient rats after extended disuse. Menopause 2013; 19:1267-76. [PMID: 22713863 DOI: 10.1097/gme.0b013e318255657f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Both estrogen and mechanical loading regulate bone maintenance. However, mechanical overload seems less effective in enhancing bone mineral density (BMD) in estrogen-deficient women. The aim of this study was to determine whether estradiol (E2) influences early-phase bone adaptations to reambulation (REAMB) and/or rehabilitation exercises after hindlimb unloading (HLU) of ovariectomized rats. METHODS Eighty-one 5-month-old female Sprague-Dawley rats were randomized into the following groups: (1) intact controls, (2) ovariectomy (OVX), (3) OVX + E2, (4) OVX + 4 weeks of HLU, (5) OVX + E2 + HLU, (6) OVX + HLU + 2 weeks of quadrupedal REAMB, (7) OVX + E2 + HLU + REAMB, (8) OVX + HLU + REAMB + supplemental climbing, jumping, and balance exercises (EX), or (9) OVX + E2 + HLU + REAMB + EX. Serial dual-energy x-ray absorptiometry scans were performed to track total body bone characteristics throughout the study, and peripheral quantitative computerized tomography was used to determine distal femoral metaphyseal bone mineral characteristics. RESULTS Total body BMD increased by 4% to 8% in all animals receiving supplemental E2, whereas BMD did not change in animals without E2. OVX reduced trabecular BMD at the femoral metaphysis, and HLU exacerbated this loss while also reducing cortical BMD. E2 protected against OVX + HLU-induced bone loss at the femoral metaphysis. Conversely, REAMB did not alter BMD, regardless of estrogen status. In the absence of E2, REAMB + EX resulted in severe bone loss after OVX + HLU, with trabecular BMD and cortical BMD measurements that were 91% and 7% below those of controls, respectively (P ≤ 0.001). However, in the presence of E2, REAMB + EX did not negatively influence bone mineral characteristics. CONCLUSIONS E2 protects against bone loss resulting from combined OVX + HLU of rodents. In the absence of estrogen, exercise induces disadvantageous early-phase bone adaptations after extended disuse.
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Shirazi-Fard Y, Kupke JS, Bloomfield SA, Hogan HA. Discordant recovery of bone mass and mechanical properties during prolonged recovery from disuse. Bone 2013; 52:433-43. [PMID: 23017660 DOI: 10.1016/j.bone.2012.09.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 09/14/2012] [Accepted: 09/14/2012] [Indexed: 11/28/2022]
Abstract
Profound bone loss at weight bearing sites is a primary effect of long-duration spaceflight. Moreover, a significant increase in estimated fracture risk remains even 1 year after returning to Earth; hence, it is important to define how quickly bone integrity can recover following prolonged disuse. This study characterized the loss and recovery dynamics of bone following a period of rodent hindlimb unloading in three anatomic sites. We hypothesized that the rat femoral neck would exhibit a discordant recovery dynamic most similar to that observed in astronauts' proximal femur; that is, bone mineral content (absolute mass) at this site would recover faster and more completely than would bone density and cortical area, and they will all recover before bone strength does. We characterized loss and long-term recovery of densitometric properties at the femoral neck, proximal tibia metaphysis, and tibia diaphysis, and also mechanical properties at the femoral neck and tibia diaphysis for which mechanical testing is amenable. We assessed the relationship between calculated strength indices and measured mechanical properties. Adult male Sprague-Dawley rats (6 months) were assigned to baseline, age-matched control (AC), and hindlimb unloaded (HU) groups. The HU group was unloaded for 28 days and then returned to normal cage activity for 84 days of weight bearing recovery (3 times the duration of HU). Fifteen animals were euthanized from each of the HU and AC groups on days 28, 56, 84, and 112 of the study. At baseline and then every 28 days in vivo longitudinal pQCT scans were taken at proximal tibia metaphysis (PTM) and tibia diaphysis (TD); ex vivo pQCT scans were taken later at the femoral neck (FN). TD and FN were tested to failure to measure mechanical properties. The hypothesis that the femoral neck in rats will exhibit a discordant recovery dynamic most similar to that observed in astronauts' proximal femurs was not supported by our data. At the femoral neck, densitometric and geometric variables (total BMC, total vBMD, cancellous vBMD, and cortical area) recovered to age-matched control levels after a recovery period twice the duration of unloading. Contrary to our hypothesis, changes in densitometric variables at the PTM provided a better model for changes in the human femoral neck with prolonged weightlessness. Following 28 days of HU, PTM total BMC recovered to age-matched control levels after roughly two times the duration of unloading; however, total vBMD did not recover even after three recovery periods. Cortical thinning occurred at the PTM following HU likely due to inhibition of periosteal growth; cortical shell thickness did not recover even after three recovery periods. Calculated strength indices suggested a loss in strength at the tibial diaphysis, which was not confirmed with direct testing of mechanical properties. HU had no effect on maximum fracture force at mid-tibia diaphysis; however, femoral neck experienced a significant loss of maximum force due to unloading that fully recovered after 28 days. Estimated strength indices for the femoral neck suggested a recovery period of 56 days in contrast to the 28-day recovery that was observed with mechanical testing. However, the inaccuracy of strength indices vs. directly measured mechanical properties highlights the continued importance of ground based animal models and mechanical testing. Our results demonstrate that the PTM in the rat better matches loss and recovery dynamics observed in astronauts' proximal femur than does the rat FN, at least in terms of densitometric variables. More complete utility of the rat PTM as a model in this case, however, depends upon meaningful characterization of changes in mechanical properties as well.
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Affiliation(s)
- Yasaman Shirazi-Fard
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA.
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14
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Miyagawa K, Kozai Y, Ito Y, Furuhama T, Naruse K, Nonaka K, Nagai Y, Yamato H, Kashima I, Ohya K, Aoki K, Mikuni-Takagaki Y. A novel underuse model shows that inactivity but not ovariectomy determines the deteriorated material properties and geometry of cortical bone in the tibia of adult rats. J Bone Miner Metab 2011; 29:422-36. [PMID: 21127921 PMCID: PMC3132588 DOI: 10.1007/s00774-010-0241-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 10/14/2010] [Indexed: 11/23/2022]
Abstract
Our goal in this study was to determine to what extent the physiologic consequences of ovariectomy (OVX) in bones are exacerbated by a lack of daily activity such as walking. We forced 14-week-old female rats to be inactive for 15 weeks with a unique experimental system that prevents standing and walking while allowing other movements. Tibiae, femora, and 4th lumbar vertebrae were analyzed by peripheral quantitative computed tomography (pQCT), microfocused X-ray computed tomography (micro-CT), histology, histomorphometry, Raman spectroscopy, and the three-point bending test. Contrary to our expectation, the exacerbation was very much limited to the cancellous bone parameters. Parameters of femur and tibia cortical bone were affected by the forced inactivity but not by OVX: (1) cross-sectional moment of inertia was significantly smaller in Sham-Inactive rat bones than that of their walking counterparts; (2) the number of sclerostin-positive osteocytes per unit cross-sectional area was larger in Sham-Inactive rat bones than in Sham-Walking rat bones; and (3) material properties such as ultimate stress of inactive rat tibia was lower than that of their walking counterparts. Of note, the additive effect of inactivity and OVX was seen only in a few parameters, such as the cancellous bone mineral density of the lumbar vertebrae and the structural parameters of cancellous bone in the lumbar vertebrae/tibiae. It is concluded that the lack of daily activity is detrimental to the strength and quality of cortical bone in the femur and tibia of rats, while lack of estrogen is not. Our inactive rat model, with the older rats, will aid the study of postmenopausal osteoporosis, the etiology of which may be both hormonal and mechanical.
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Affiliation(s)
- Kazuaki Miyagawa
- Division of Biochemistry and Molecular Biology, Department of Functional Biology, Kanagawa Dental College, 82 Inaokacho, Yokosuka, 238-8580 Japan
- Department of Bone and Mineral Research, Osaka Medical Center and Research Institute for Maternal and Child Health (in conjunction with the First Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry), Osaka, 594-1101 Japan
| | - Yusuke Kozai
- Department of Maxillofacial Diagnostic Science, Kanagawa Dental College, Yokosuka, Japan
| | - Yumi Ito
- Yokohama Training Center, Kanagawa Dental College, Yokohama, Japan
| | - Takami Furuhama
- Division of Biochemistry and Molecular Biology, Department of Functional Biology, Kanagawa Dental College, 82 Inaokacho, Yokosuka, 238-8580 Japan
| | - Kouji Naruse
- Department of Orthopedic Surgery, Kitasato University School of Medicine, Sagamihara, Japan
| | | | - Yumiko Nagai
- Kureha Special Laboratory Co., Ltd, Tokyo, Japan
| | | | - Isamu Kashima
- Department of Maxillofacial Diagnostic Science, Kanagawa Dental College, Yokosuka, Japan
| | - Keiichi Ohya
- Section of Pharmacology, Department of Hard Tissue Engineering, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kazuhiro Aoki
- Section of Pharmacology, Department of Hard Tissue Engineering, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuko Mikuni-Takagaki
- Division of Biochemistry and Molecular Biology, Department of Functional Biology, Kanagawa Dental College, 82 Inaokacho, Yokosuka, 238-8580 Japan
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15
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Goulet GC, Halonen NR, Koch LG, Britton SL, Zernicke RF, Kozloff KM. Osteoblast response to ovariectomy is enhanced in intrinsically high aerobic-capacity rats. Calcif Tissue Int 2011; 88:325-35. [PMID: 21212941 PMCID: PMC3297469 DOI: 10.1007/s00223-010-9457-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 12/12/2010] [Indexed: 12/20/2022]
Abstract
The role of exercise in promoting bone health is typically attributed to increased mechanical loading, which induces functional adaptation. Recent evidence suggests that habitual aerobic exercise has influence at the cellular level as well. The effect of aerobic capacity on osteoblast-lineage cell differentiation and function as well as skeletal phenotype is unknown. Using a rat model of high-capacity and low-capacity runners (HCRs and LCRs, respectively), in which an intrinsic functional genomic difference in aerobic capacity exists between nontrained animals, this study evaluated the effects of aerobic capacity on measures of bone mass and strength as well as osteoblast activity following ovariectomy. The ovariectomized rat emulates the clinical features of the estrogen-depleted human skeleton and represents a valuable model for studying short-term upregulation of osteoblast activity. We hypothesized that intrinsically high aerobic capacity would augment osteoblast response, which would mitigate the deleterious effects of hormone withdrawal. Femora and tibiae were assessed by micro-computed tomography, mechanical testing, and dynamic histomorphometry. HCRs had enhanced femoral tissue mineral density and estimated elastic modulus relative to LCRs. At 4 weeks postovariectomy, HCRs demonstrated a more robust osteoblast response. Markers of bone formation were upregulated to a greater extent in HCRs than LCRs, suggesting a role for aerobic capacity in governing osteoblast activity. Results from this and future studies will help to identify the influence of cellular aerobic metabolism on bone health, which may lead to new strategies for targeting diseases of the skeleton.
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Affiliation(s)
- G. C. Goulet
- Department of Orthopaedic Surgery, University of Michigan, 2015 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA
| | - N. R. Halonen
- Department of Orthopaedic Surgery, University of Michigan, 2015 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA
| | - L. G. Koch
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI 48109-2200, USA
| | - S. L. Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI 48109-2200, USA
| | - R. F. Zernicke
- Department of Orthopaedic Surgery, School of Kinesiology, University of Michigan, Ann Arbor, MI 48109-2200, USA
| | - K. M. Kozloff
- Department of Orthopaedic Surgery, University of Michigan, 2015 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA
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16
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Sarban S, Senkoylu A, Isikan UE, Korkusuz P, Korkusuz F. Can rhBMP-2 containing collagen sponges enhance bone repair in ovariectomized rats?: a preliminary study. Clin Orthop Relat Res 2009; 467:3113-20. [PMID: 19653054 PMCID: PMC2772906 DOI: 10.1007/s11999-009-1004-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 07/11/2009] [Indexed: 01/31/2023]
Abstract
With an aging population the frequency of postmenopausal fractures is increasing. Methods to enhance the repair of osteoporotic bone repair therefore become more important to reduce the society burden of care. We asked if absorbable collagen sponges containing recombinant human bone morphogenetic protein-2 (rhBMP-2) have the potential to enhance bone repair. We randomly assigned 40 rats into the ovariectomy and sham operation groups. A segmental defect was created in the right tibia 12 weeks after ovariectomy. rhBMP-2-containing absorbable collagen sponges were implanted into the defect in half of the animals in each group. We analyzed radiographs and histological sections and performed three-point bending tests to assess repair. Radiological scores in the rhBMP-2 applied rats were higher than those in controls at the end of 8 weeks after tibial osteotomy. The specimens failed under higher loads in the rhBMP-2-applied groups and histology revealed a higher fracture healing score, including callus formation, bone union, marrow changes, and cortex remodeling. We observed no adverse tissue responses such as fibrous connective tissue formation and inflammatory cellular infiltration. rhBMP-2 in absorbable collagen sponges enhanced bone repair in segmental tibial defects of ovariectomized rats. The sponges with rhBMP-2 appeared to enhance bone repair.
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Affiliation(s)
- Sezgin Sarban
- Department of Orthopaedic Surgery, Harran University Faculty of Medicine, Sanliurfa, Turkey
| | - Alparslan Senkoylu
- Department of Orthopaedic Surgery, Gazi University Faculty of Medicine, Ankara, Turkey
| | - U. Erdem Isikan
- Department of Orthopaedic Surgery, Harran University Faculty of Medicine, Sanliurfa, Turkey
| | - Petek Korkusuz
- Department of Histology and Embryology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Feza Korkusuz
- Department of Biomedical Engineering, Institute of Natural Sciences, Middle East Technical University, 100 Yil, Ankara, 06531 Turkey
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17
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Brouwers JEM, Lambers FM, van Rietbergen B, Ito K, Huiskes R. Comparison of bone loss induced by ovariectomy and neurectomy in rats analyzed by in vivo micro-CT. J Orthop Res 2009; 27:1521-7. [PMID: 19437511 DOI: 10.1002/jor.20913] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We hypothesized that osteoporosis due to estrogen deficiency progresses faster than due to disuse and that at the same amount of bone loss, disuse leads to less favorable bone structure and mechanical properties than estrogen deficiency. Adult rats were either ovariectomized (OVX) (n = 9) or neurectomized (NX) (n = 8). At week 0, 1, 2, 3, and 4, in vivo micro-CT scans were made of the proximal tibia. Segmented CT-scans at weeks 0 and 4 were used to build a 3D voxel-based micro finite element model (FEM). Displacement in the longitudinal direction was prescribed at the proximal end leading to a compression step of 1%. The severe reduction in metaphyseal bone volume fraction was not significantly different between OVX and NX. Epiphyseal bone loss was less severe in both groups, and BV/TV was significantly lower after NX. Trabecular separation and degree of anisotropy in the metaphysis and connectivity and trabecular number in the epiphysis were significantly more deteriorated after NX. FEM-derived stiffness decreased in both groups, but more after NX. Osteoporosis due to estrogen-deficiency progressed overall at a rate similar to osteoporosis due to disuse. At the same amount of induced bone loss, disuse led to more deteriorated bone structure and mechanical properties than estrogen deficiency.
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Affiliation(s)
- Julienne E M Brouwers
- Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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18
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Ohtani J, Hernandez RAM, Sunagawa H, Fujita T, Kawata T, Kaku M, Motokawa M, Tsuka N, Koseki H, Matsuda Y, Hayashi H, Abedini S, Tanne K. A newly developed snack effective for enhancing bone volume. Nutr J 2009; 8:30. [PMID: 19573248 PMCID: PMC2711110 DOI: 10.1186/1475-2891-8-30] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 07/03/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The incidence of primary osteoporosis is higher in Japan than in USA and European countries. Recently, the importance of preventive medicine has been gradually recognized in the field of orthopaedic surgery with a concept that peak bone mass should be increased in childhood as much as possible for the prevention of osteoporosis. Under such background, we have developed a new bean snack with an aim to improve bone volume loss. In this study, we examined the effects of a newly developed snack on bone volume and density in osteoporosis model mice. METHODS Orchiectomy (ORX) and ovariectomy (OVX) were performed for C57BL/6J mice of twelve-week-old (Jackson Laboratory, Bar Harbar, ME, USA) were used in this experiment. We prepared and given three types of powder diet e.g.: normal calcium diet (NCD, Ca: 0.9%, Clea Japan Co., Tokyo, Japan), low calcium diet (LCD, Ca: 0.63%, Clea Japan Co.,) and special diet (SCD, Ca: 0.9%). Eighteen weeks after surgery, all the animals were sacrified and prepared for histomorphometric analysis to quantify bone density and bone mineral content. RESULTS As a result of histomorphometric examination, SCD was revealed to enhance bone volume irrespective of age and sex. The bone density was increased significantly in osteoporosis model mice fed the newly developmental snack as compared with the control mice. The bone mineral content was also enhanced significantly. These phenomena were revealed in both sexes. CONCLUSION It is shown that the newly developed bean snack is highly effective for the improvement of bone volume loss irrespective of sex. We demonstrated that newly developmental snack supplements may be a useful preventive measure for Japanese whose bone mineral density values are less than the ideal condition.
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Affiliation(s)
- Junji Ohtani
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Rene Arturo Marquez Hernandez
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Hiroko Sunagawa
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Tadashi Fujita
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Toshitsugu Kawata
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Masato Kaku
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Masahide Motokawa
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Natsumi Tsuka
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Hiroyuki Koseki
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Yayoi Matsuda
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Hidetaka Hayashi
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Sara Abedini
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
| | - Kazuo Tanne
- Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-city, Hiroshima, Japan
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Yarrow JF, Conover CF, Purandare AV, Bhakta AM, Zheng N, Conrad B, Altman MK, Franz SE, Wronski TJ, Borst SE. Supraphysiological testosterone enanthate administration prevents bone loss and augments bone strength in gonadectomized male and female rats. Am J Physiol Endocrinol Metab 2008; 295:E1213-22. [PMID: 18780767 DOI: 10.1152/ajpendo.90640.2008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High-dose testosterone enanthate (TE) may prevent hypogonadism-induced osteopenia. For this study, 3-mo-old male and female Fisher SAS rats underwent sham surgery, gonadectomy (GX), or GX plus 28 days TE administration (7.0 mg/wk). GX reduced serum sex hormones (i.e., testosterone, dihydrotestosterone, and estradiol) (P < 0.05) in both sexes and bone concentrations of testosterone (males only), and estradiol (females only). GX also elevated urine deoxypyridinoline/creatinine in both sexes and serum osteocalcin (females only), findings that are consistent with high-turnover osteopenia. GX reduced cancellous bone volume (CBV) and increased osteoid surfaces in tibia of both sexes. GX males also experienced reduced trabecular number and width and increased trabecular separation, whereas GX females experienced increased osteoblast and osteoid surfaces. Bone biomechanical characteristics remained unaffected by GX, except that femoral stiffness was reduced in females. In contrast, TE administration to GX rats elevated serum and bone androgens to supraphysiological concentrations in both sexes but altered neither serum nor bone estradiol in males. Additionally, TE did not prevent GX-induced reductions in serum or bone estradiol in females. TE also reduced markers of high-turnover osteopenia in both sexes. In males, TE prevented GX-induced changes in trabecular number and separation, CBV, and osteoid surfaces while diminishing osteoblast and osteoclast surfaces; however, these changes were not fully prevented in females. In both sexes, TE increased femoral length and femoral maximal strength to above that of Sham and GX animals while preventing the loss of femoral stiffness in females. In conclusion, TE administration appears protective of cancellous bone in male rats and augments cortical bone strength in both sexes.
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Affiliation(s)
- Joshua F Yarrow
- Geriatric Research, Education and Clinical Center, Veterans Administration Medical Center, Gainesville, Florida, USA
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