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Hatakeyama J, Inoue S, Li C, Takamura D, Jiang H, Kuroki H, Moriyama H. Effects of acute- and long-term aerobic exercises at different intensities on bone in mice. J Bone Miner Metab 2024; 42:185-195. [PMID: 38349543 DOI: 10.1007/s00774-023-01491-2] [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: 06/27/2023] [Accepted: 12/04/2023] [Indexed: 04/01/2024]
Abstract
INTRODUCTION Exercise intensity determines the benefits of aerobic exercise. Our objectives were, in aerobic exercise at different intensities, to determine (1) changes in bone metabolism-related genes after acute exercise and (2) changes in bone mass, strength, remodeling, and bone formation-related proteins after long-term exercise. MATERIALS AND METHODS Total 36 male C57BL/6J mice were divided into a control group and exercise groups at 3 different intensities: low, moderate, or high group. Each exercise group was assigned to acute- or long-term exercise groups. Tibias after acute exercise were evaluated by real-time PCR analysis. Furthermore, hindlimbs of long-term exercise were assessed by micro-CT, biomechanical, histological, and immunohistochemical analyses. RESULTS Acute moderate-intensity exercise decreased RANKL level as bone resorption marker, whereas low- and high-intensity exercise did not alter it. Additionally, only long-term exercise at moderate intensity increased bone mass and strength. Moderate-intensity exercise promoted osteoblast activity and suppressed osteoclast activity. After low- and high-intensity exercise, osteoblast and osteoclast activity were unchanged. An increase in the number of β-catenin-positive cells and a decrease in sclerostin-positive cells were observed in the only moderate group. CONCLUSION These results showed that moderate-intensity exercise can inhibit bone resorption earlier, and long-term exercise can increase bone mass and strength through promoted bone formation via the Wnt/β-catenin activation. High-intensity exercise, traditionally considered better for bone, may fail to stimulate bone remodeling, leading to no change in bone mass and strength. Our findings suggest that moderate-intensity exercise, neither too low nor high, can maintain bone health.
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Affiliation(s)
- Junpei Hatakeyama
- Department of Rehabilitation Science, Graduate School of Health Sciences, Kobe University, Kobe, Japan
| | - Shota Inoue
- Department of Rehabilitation Science, Graduate School of Health Sciences, Kobe University, Kobe, Japan
| | - Changxin Li
- Department of Rehabilitation Science, Graduate School of Health Sciences, Kobe University, Kobe, Japan
| | - Daisuke Takamura
- Department of Rehabilitation Science, Graduate School of Health Sciences, Kobe University, Kobe, Japan
- Department of Rehabilitation, Kobe City Medical Center General Hospital, Chuo-ku, Kobe, Japan
| | - Hanlin Jiang
- Department of Rehabilitation Science, Graduate School of Health Sciences, Kobe University, Kobe, Japan
| | - Hiroshi Kuroki
- Department of Physical Therapy, Graduate School of Medicine, Human Health Sciences, Kyoto University, Kyoto, Japan
| | - Hideki Moriyama
- Life and Medical Sciences Area, Health Sciences Discipline, Kobe University, Tomogaoka 7-10-2, Suma-ku, Kobe, Hyogo, 654-0142, Japan.
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Wallace IJ, Toya C, Peña Muñoz MA, Meyer JV, Busby T, Reynolds AZ, Martinez J, Thompson TT, Miller-Moore M, Harris AR, Rios R, Martinez A, Jashashvili T, Ruff CB. Effects of the energy balance transition on bone mass and strength. Sci Rep 2023; 13:15204. [PMID: 37709850 PMCID: PMC10502131 DOI: 10.1038/s41598-023-42467-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023] Open
Abstract
Chronic positive energy balance has surged among societies worldwide due to increasing dietary energy intake and decreasing physical activity, a phenomenon called the energy balance transition. Here, we investigate the effects of this transition on bone mass and strength. We focus on the Indigenous peoples of New Mexico in the United States, a rare case of a group for which data can be compared between individuals living before and after the start of the transition. We show that since the transition began, bone strength in the leg has markedly decreased, even though bone mass has apparently increased. Decreased bone strength, coupled with a high prevalence of obesity, has resulted in many people today having weaker bones that must sustain excessively heavy loads, potentially heightening their risk of a bone fracture. These findings may provide insight into more widespread upward trends in bone fragility and fracture risk among societies undergoing the energy balance transition.
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Affiliation(s)
- Ian J Wallace
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA.
| | | | | | - Jana Valesca Meyer
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Taylor Busby
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Adam Z Reynolds
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Jordan Martinez
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | | | - Marcus Miller-Moore
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Alexandra R Harris
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Roberto Rios
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Alexis Martinez
- Department of Anthropology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Tea Jashashvili
- Department of Integrative Anatomical Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Christopher B Ruff
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
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Massing T, Will K, Müller M, Aleith J, Lindner T, Warkentin M, Müller-Hilke B, Mittlmeier T. Prolonged treadmill training is not able to prevent ovariectomy-induced bone loss. Front Physiol 2022; 13:1078857. [PMID: 36589439 PMCID: PMC9800899 DOI: 10.3389/fphys.2022.1078857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Introduction: Exercise is widely recognized as prophylaxis for osteoporosis. However, exactly which type of exercise is best to prevent loss of bone mass remains undefined. To find an appropriate form of treadmill exercise that would ameliorate postmenopausal loss of cortical and trabecular structures, we compared various training regimen in ovariectomized (OVX) C57BL/6J mice. Methods: Common to all regimen were training durations of 14 weeks including five 30 min-sessions per week. Two groups-one sham operated, one OVX-served as controls that did not perform any training. Three OVX groups ran at constant speed, either without any incline or at 20° in- and 20° decline, respectively. An additional OVX group ran an interval training, an alternation between intensive tempo sections and so-called slower regeneration phases. Femoral and humeral bone structures were assessed via micro-computed tomography (μCT), biomechanical stability of the femora via 3-point bending test, muscle volumes of the posterior extremities via magnetic resonance imaging (MRI), and bone metabolic parameters via ELISA on peripheral blood. Result: OVX resulted in loss of bone mass and stability and a transient rise in the N-terminal collagen type I pro-peptide (PINP). Training resulted in increased muscle volumes of the heart and the lower extremities as well as increased running velocities. However, none of the exercise programs was able to prevent ovariectomyinduced loss of bone mass. Discussion: These data therefore suggest that axial loading and tensile strain do not suffice as prophylaxis for postmenopausal osteoporosis yet may need to be complemented by low dose pharmaceutics or dietary supplements.
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Affiliation(s)
- Tim Massing
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany,Core Facility for Cell Sorting and Cell Analysis, Rostock University Medical Center, Rostock, Germany,*Correspondence: Thomas Mittlmeier,
| | - Konstantin Will
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany,Core Facility for Cell Sorting and Cell Analysis, Rostock University Medical Center, Rostock, Germany,*Correspondence: Thomas Mittlmeier,
| | - Michael Müller
- Core Facility for Cell Sorting and Cell Analysis, Rostock University Medical Center, Rostock, Germany
| | - Johann Aleith
- Core Facility for Cell Sorting and Cell Analysis, Rostock University Medical Center, Rostock, Germany
| | - Tobias Lindner
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, Rostock, Germany
| | - Mareike Warkentin
- Department of Material Science and Medical Engineering, Rostock University, Rostock, Germany
| | - Brigitte Müller-Hilke
- Core Facility for Cell Sorting and Cell Analysis, Rostock University Medical Center, Rostock, Germany
| | - Thomas Mittlmeier
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany,*Correspondence: Thomas Mittlmeier,
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Matsumoto T, Mukohara A. Effects of Whole-Body Vibration on Breast Cancer Bone Metastasis and Vascularization in Mice. Calcif Tissue Int 2022; 111:535-545. [PMID: 35896728 DOI: 10.1007/s00223-022-01009-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/07/2022] [Indexed: 11/12/2022]
Abstract
We evaluated whether whole-body vibration (WBV) prevented bone loss induced by breast cancer (BC) metastasis and the involvement of bone marrow vasculature. One day after orthotopic transplantation of mammary 4T1 tumor cells, 8-week-old BALB/c mice were subjected to 0.3 g/90 Hz vertical vibration for 20 min/day for 5 days/week (BC-WBV) or sham-handled (BC-Sham) over 3 weeks. Age-matched intact mice (Intact) were also sham-handled. Both tibiae were harvested from BC-WBV (n = 7), BC-Sham (n = 9), and Intact (n = 5) mice for bone structure imaging by synchrotron radiation-based computed tomography (SRCT) and hematoxylin and eosin staining, whereas right tibiae were harvested from other BC-WBV and BC-Sham (n = 6 each) mice for vascular imaging by SRCT. Tumor cells were similarly widespread in the marrow in BC-WBV and BC-Sham mice. In BC-Sham mice, cortical bone volume, trabecular volume fraction, trabecular thickness, trabecular number density, and bone mineral density were smaller, and marrow volume and trabecular separation were larger than in Intact mice. However, although trabecular thickness was smaller in BC-WBV than Intact mice, the others did not differ between the two groups. Serum osteocalcin tended to be higher in BC-WBV than BC-Sham mice. Compared with BC-Sham mice, BC-WBV mice had a smaller vessel diameter, a trend of a larger vessel number density, and smaller vessel diameter heterogeneity. In conclusion, WBV mitigates bone loss in BC bone metastasis, which may be partly due to increased bone anabolism. The alteration of marrow vasculature appears to be favorable for anti-tumor drug delivery. Further studies are needed to clarify the multiple actions of WBV on bone, tumor, and marrow vasculature and how they contribute to bone protection in BC metastasis.
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Affiliation(s)
- Takeshi Matsumoto
- Biomedical Engineering Laboratory, Tokushima University Graduate School of Technology, Industrial and Social Sciences, 770-8506, Tokushima, Japan.
| | - Akihiro Mukohara
- Biomedical Engineering Laboratory, Tokushima University Faculty of Science and Technology, 770-8506, Tokushima, Japan
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Chen J, Lazarenko OP, Carvalho E, Blackburn ML, Shankar K, Wankhade UD, Børsheim E. Short-Term Increased Physical Activity During Early Life Affects High-Fat Diet-Induced Bone Loss in Young Adult Mice. JBMR Plus 2021; 5:e10508. [PMID: 34258504 PMCID: PMC8260814 DOI: 10.1002/jbm4.10508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/22/2021] [Accepted: 04/21/2021] [Indexed: 01/01/2023] Open
Abstract
Mechanical stresses associated with physical activity (PA) have beneficial effects on increasing BMD and improving bone quality. However, a high-fat diet (HFD) and obesity tend to have negative effects on bone, by increasing bone marrow adiposity leading to increased excretion of proinflammatory cytokines, which activate RANKL-induced bone resorption. In the current study, whether short-term increased PA via access to voluntary wheel running during early life has persistent and protective effects on HFD-induced bone resorption was investigated. Sixty 4-week-old male C57BL6/J mice were divided into two groups postweaning: without or with PA (access to voluntary running wheel 7-8 km/day) for 4 weeks. After 4 weeks with or without PA, mice were further subdivided into control diet or HFD groups for 8 weeks, and then all animals were switched back to control diet for an additional 4 weeks. Mice from the HFD groups were significantly heavier and obese; however, after 4 weeks of additional control diet their body weights returned to levels of mice on continuous control diet. Using μ-CT and confirmed by pQCT of tibias and spines ex vivo, it was determined that bone volume and trabecular BMD were significantly increased with PA in control diet animals compared with sedentary animals without access to wheels, and such anabolic effects of PA on bone were sustained after ceasing PA in adult mice. Eight weeks of a HFD deteriorated bone development in mice. Unexpectedly, early-life PA did not prevent persistent effects of HFD on deteriorating bone quality; in fact, it exacerbated a HFD-induced inflammation, osteoclastogenesis, and trabecular bone loss in adult mice. In accordance with these data, signal transduction studies revealed that a HFD-induced Ezh2, DNA methyltransferase 3a, and nuclear factor of activated T-cells 1 expression were amplified in nonadherent hematopoietic cells. In conclusion, short-term increased PA in early life is capable of increasing bone mass; however, it alters the HFD-induced bone marrow hematopoietic cell-differentiation program to exacerbate increased bone resorption if PA is halted. © 2021 Arkansas Children's Nutrition Center. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Jin‐Ran Chen
- Arkansas Children's Nutrition CenterLittle RockARUSA
- Department of PediatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Oxana P Lazarenko
- Arkansas Children's Nutrition CenterLittle RockARUSA
- Department of PediatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Eugenia Carvalho
- Arkansas Children's Research InstituteLittle RockARUSA
- Department of GeriatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Michael L Blackburn
- Arkansas Children's Nutrition CenterLittle RockARUSA
- Department of PediatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Kartik Shankar
- Arkansas Children's Nutrition CenterLittle RockARUSA
- Department of PediatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
- Present address:
Department of Pediatrics, Section of NutritionUniversity of Colorado School of MedicineAuroraCOUSA
| | - Umesh D Wankhade
- Arkansas Children's Nutrition CenterLittle RockARUSA
- Department of PediatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Elisabet Børsheim
- Arkansas Children's Nutrition CenterLittle RockARUSA
- Department of PediatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
- Arkansas Children's Research InstituteLittle RockARUSA
- Department of GeriatricsUniversity of Arkansas for Medical SciencesLittle RockARUSA
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Sun Y, Yuan Y, Wu W, Lei L, Zhang L. The effects of locomotion on bone marrow mesenchymal stem cell fate: insight into mechanical regulation and bone formation. Cell Biosci 2021; 11:88. [PMID: 34001272 PMCID: PMC8130302 DOI: 10.1186/s13578-021-00601-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 05/04/2021] [Indexed: 02/06/2023] Open
Abstract
Bone marrow mesenchymal stem cells (BMSCs) refer to a heterogeneous population of cells with the capacity for self-renewal. BMSCs have multi-directional differentiation potential and can differentiate into chondrocytes, osteoblasts, and adipocytes under specific microenvironment or mechanical regulation. The activities of BMSCs are closely related to bone quality. Previous studies have shown that BMSCs and their lineage-differentiated progeny (for example, osteoblasts), and osteocytes are mechanosensitive in bone. Thus, a goal of this review is to discuss how these ubiquious signals arising from mechanical stimulation are perceived by BMSCs and then how the cells respond to them. Studies in recent years reported a significant effect of locomotion on the migration, proliferation and differentiation of BMSCs, thus, contributing to our bone mass. This regulation is realized by the various intersecting signaling pathways including RhoA/Rock, IFG, BMP and Wnt signalling. The mechanoresponse of BMSCs also provides guidance for maintaining bone health by taking appropriate exercises. This review will summarize the regulatory effects of locomotion/mechanical loading on BMSCs activities. Besides, a number of signalling pathways govern MSC fate towards osteogenic or adipocytic differentiation will be discussed. The understanding of mechanoresponse of BMSCs makes the foundation for translational medicine.
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Affiliation(s)
- Yuanxiu Sun
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Yu Yuan
- School of Sport and Health, Guangzhou Sport University, Guangzhou, 510500, Guangdong, China
| | - Wei Wu
- School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China
| | - Le Lei
- School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China
| | - Lingli Zhang
- School of Physical Education & Sports Science, South China Normal University, 55 Zhongshan Road West, Tianhe District, Guangzhou, 510631, Guangdong, China.
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Bird EE, Kivell TL, Skinner MM. Cortical and trabecular bone structure of the hominoid capitate. J Anat 2021; 239:351-373. [PMID: 33942895 PMCID: PMC8273598 DOI: 10.1111/joa.13437] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 01/02/2023] Open
Abstract
Morphological variation in the hominoid capitate has been linked to differences in habitual locomotor activity due to its importance in movement and load transfer at the midcarpal joint proximally and carpometacarpal joints distally. Although the shape of bones and their articulations are linked to joint mobility, the internal structure of bones has been shown experimentally to reflect, at least in part, the loading direction and magnitude experienced by the bone. To date, it is uncertain whether locomotor differences among hominoids are reflected in the bone microarchitecture of the capitate. Here, we apply a whole‐bone methodology to quantify the cortical and trabecular architecture (separately and combined) of the capitate across bipedal (modern Homo sapiens), knuckle‐walking (Pan paniscus, Pan troglodytes, Gorilla sp.), and suspensory (Pongo sp.) hominoids (n = 69). It is hypothesized that variation in bone microarchitecture will differentiate these locomotor groups, reflecting differences in habitual postures and presumed loading force and direction. Additionally, it is hypothesized that trabecular and cortical architecture in the proximal and distal regions, as a result of being part of mechanically divergent joints proximally and distally, will differ across these portions of the capitate. Results indicate that the capitate of knuckle‐walking and suspensory hominoids is differentiated from bipedal Homo primarily by significantly thicker distal cortical bone. Knuckle‐walking taxa are further differentiated from suspensory and bipedal taxa by more isotropic trabeculae in the proximal capitate. An allometric analysis indicates that size is not a significant determinate of bone variation across hominoids, although sexual dimorphism may influence some parameters within Gorilla. Results suggest that internal trabecular and cortical bone is subjected to different forces and functional adaptation responses across the capitate (and possibly other short bones). Additionally, while separating trabecular and cortical bone is normal protocol of current whole‐bone methodologies, this study shows that when applied to carpals, removing or studying the cortical bone separately potentially obfuscates functionally relevant signals in bone structure.
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Affiliation(s)
- Emma E Bird
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Tracy L Kivell
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Matthew M Skinner
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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Swimming as Treatment for Osteoporosis: A Systematic Review and Meta-analysis. BIOMED RESEARCH INTERNATIONAL 2021; 2020:6210201. [PMID: 32509864 PMCID: PMC7245678 DOI: 10.1155/2020/6210201] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 02/16/2020] [Accepted: 03/11/2020] [Indexed: 01/06/2023]
Abstract
Osteoporosis is a chronic disease that seriously affects human health and quality of life. This study is aimed at determining whether swimming had an effect on the bone mineral density (BMD) of the spine and femoral neck in postmenopausal and premenopausal osteoporosis patients. We retrieved relevant literature and analyzed data from randomized controlled trials to assess the effect of swimming on BMD in postmenopausal and premenopausal women. Relevant studies, with no language restrictions, from inception to September 2019, were retrieved from the PubMed, Cochrane, EMBASE, and EBSCO databases independently by two investigators. The keywords used for the literature search were “osteoporosis” and “swimming.” The main results included BMD and T-score. We searched 256 relevant articles and finally screened five articles, including 263 participants. Lumbar spine density was mentioned in three articles. Although the heterogeneity of lumbar vertebral density is moderate, the analysis of swimmers to nonswimmers shows that the lumbar vertebral density in swimmers is improved [heterogeneity: chi2 = 5.16, df = 2 (P = 0.08); I2 = 61%]. We analyzed the following heterogeneous subgroups: subgroup 1 (3–6 hours) and subgroup 2 (<3 hours). The BMD in subgroup 1 was significantly higher than that in the placebo, while no effect on BMD was found in subgroup 2 [heterogeneity: chi2 = 0.15, df = 3 (P = 0.70); I2 = 0%]. According to the current evidence, swimming may improve the BMD of postmenopausal women participants, if the swimming time is between 3 and 6 hours, especially in long-term swimmers. However, the effectiveness of swimming does require further investigation.
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McGrath C, Little-Letsinger SE, Sankaran JS, Sen B, Xie Z, Styner MA, Zong X, Chen W, Rubin J, Klett EL, Coleman RA, Styner M. Exercise Increases Bone in SEIPIN Deficient Lipodystrophy, Despite Low Marrow Adiposity. Front Endocrinol (Lausanne) 2021; 12:782194. [PMID: 35145475 PMCID: PMC8822583 DOI: 10.3389/fendo.2021.782194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/20/2021] [Indexed: 01/12/2023] Open
Abstract
Exercise, typically beneficial for skeletal health, has not yet been studied in lipodystrophy, a condition characterized by paucity of white adipose tissue, with eventual diabetes, and steatosis. We applied a mouse model of global deficiency of Bscl2 (SEIPIN), required for lipid droplet formation. Male twelve-week-old B6 knockouts (KO) and wild type (WT) littermates were assigned six-weeks of voluntary, running exercise (E) versus non-exercise (N=5-8). KO weighed 14% less than WT (p=0.01) and exhibited an absence of epididymal adipose tissue; KO liver Plin1 via qPCR was 9-fold that of WT (p=0.04), consistent with steatosis. Bone marrow adipose tissue (BMAT), unlike white adipose, was measurable, although 40.5% lower in KO vs WT (p=0.0003) via 9.4T MRI/advanced image analysis. SEIPIN ablation's most notable effect marrow adiposity was in the proximal femoral diaphysis (-56% KO vs WT, p=0.005), with relative preservation in KO-distal-femur. Bone via μCT was preserved in SEIPIN KO, though some quality parameters were attenuated. Running distance, speed, and time were comparable in KO and WT. Exercise reduced weight (-24% WT-E vs WT p<0.001) but not in KO. Notably, exercise increased trabecular BV/TV in both (+31%, KO-E vs KO, p=0.004; +14%, WT-E vs WT, p=0.006). The presence and distribution of BMAT in SEIPIN KO, though lower than WT, is unexpected and points to a uniqueness of this depot. That trabecular bone increases were achievable in both KO and WT, despite a difference in BMAT quantity/distribution, points to potential metabolic flexibility during exercise-induced skeletal anabolism.
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Affiliation(s)
- Cody McGrath
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Sarah E. Little-Letsinger
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jeyantt Srinivas Sankaran
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Buer Sen
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Zhihui Xie
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Martin A. Styner
- Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Xiaopeng Zong
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Weiqin Chen
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Janet Rubin
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- North Carolina Diabetes Research Center (NCDRC), Chapel Hill, NC, United States
| | - Eric L. Klett
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- North Carolina Diabetes Research Center (NCDRC), Chapel Hill, NC, United States
- Department of Nutrition, Gillings School of Global Public Health, UNC, Chapel Hill, NC, United States
| | - Rosalind A. Coleman
- Department of Nutrition, Gillings School of Global Public Health, UNC, Chapel Hill, NC, United States
| | - Maya Styner
- Department of Medicine, Division of Endocrinology & Metabolism, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- North Carolina Diabetes Research Center (NCDRC), Chapel Hill, NC, United States
- *Correspondence: Maya Styner,
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Smith JK. Exercise as an Adjuvant to Cartilage Regeneration Therapy. Int J Mol Sci 2020; 21:ijms21249471. [PMID: 33322825 PMCID: PMC7763351 DOI: 10.3390/ijms21249471] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/03/2020] [Accepted: 12/10/2020] [Indexed: 02/06/2023] Open
Abstract
This article provides a brief review of the pathophysiology of osteoarthritis and the ontogeny of chondrocytes and details how physical exercise improves the health of osteoarthritic joints and enhances the potential of autologous chondrocyte implants, matrix-induced autologous chondrocyte implants, and mesenchymal stem cell implants for the successful treatment of damaged articular cartilage and subchondral bone. In response to exercise, articular chondrocytes increase their production of glycosaminoglycans, bone morphogenic proteins, and anti-inflammatory cytokines and decrease their production of proinflammatory cytokines and matrix-degrading metalloproteinases. These changes are associated with improvements in cartilage organization and reductions in cartilage degeneration. Studies in humans indicate that exercise enhances joint recruitment of bone marrow-derived mesenchymal stem cells and upregulates their expression of osteogenic and chondrogenic genes, osteogenic microRNAs, and osteogenic growth factors. Rodent experiments demonstrate that exercise enhances the osteogenic potential of bone marrow-derived mesenchymal stem cells while diminishing their adipogenic potential, and that exercise done after stem cell implantation may benefit stem cell transplant viability. Physical exercise also exerts a beneficial effect on the skeletal system by decreasing immune cell production of osteoclastogenic cytokines interleukin-1β, tumor necrosis factor-α, and interferon-γ, while increasing their production of antiosteoclastogenic cytokines interleukin-10 and transforming growth factor-β. In conclusion, physical exercise done both by bone marrow-derived mesenchymal stem cell donors and recipients and by autologous chondrocyte donor recipients may improve the outcome of osteochondral regeneration therapy and improve skeletal health by downregulating osteoclastogenic cytokine production and upregulating antiosteoclastogenic cytokine production by circulating immune cells.
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Affiliation(s)
- John Kelly Smith
- Departments of Academic Affairs and Biomedical Sciences, James H. Quillen College of Medicine, East Tennessee State University, P.O. Box 70300, Johnson City, TN 37614, USA
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Little-Letsinger SE, Pagnotti GM, McGrath C, Styner M. Exercise and Diet: Uncovering Prospective Mediators of Skeletal Fragility in Bone and Marrow Adipose Tissue. Curr Osteoporos Rep 2020; 18:774-789. [PMID: 33068251 PMCID: PMC7736569 DOI: 10.1007/s11914-020-00634-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/29/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW To highlight recent basic, translational, and clinical works demonstrating exercise and diet regulation of marrow adipose tissue (MAT) and bone and how this informs current understanding of the relationship between marrow adiposity and musculoskeletal health. RECENT FINDINGS Marrow adipocytes accumulate in the bone in the setting of not only hypercaloric intake (calorie excess; e.g., diet-induced obesity) but also with hypocaloric intake (calorie restriction; e.g., anorexia), despite the fact that these states affect bone differently. With hypercaloric intake, bone quantity is largely unaffected, whereas with hypocaloric intake, bone quantity and quality are greatly diminished. Voluntary running exercise in rodents was found to lower MAT and promote bone in eucaloric and hypercaloric states, while degrading bone in hypocaloric states, suggesting differential modulation of MAT and bone, dependent upon whole-body energy status. Energy status alters bone metabolism and bioenergetics via substrate availability or excess, which plays a key role in the response of bone and MAT to mechanical stimuli. Marrow adipose tissue (MAT) is a fat depot with a potential role in-as well as responsivity to-whole-body energy metabolism. Understanding the localized function of this depot in bone cell bioenergetics and substrate storage, principally in the exercised state, will aid to uncover putative therapeutic targets for skeletal fragility.
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Affiliation(s)
- Sarah E Little-Letsinger
- Department of Medicine, Division of Endocrinology & Metabolism, University of North Carolina, Chapel Hill, NC, USA.
| | - Gabriel M Pagnotti
- Department of Medicine, Division of Endocrinology, Indiana University, Indianapolis, IN, USA
| | - Cody McGrath
- Department of Medicine, Division of Endocrinology & Metabolism, University of North Carolina, Chapel Hill, NC, USA
| | - Maya Styner
- Department of Medicine, Division of Endocrinology & Metabolism, University of North Carolina, Chapel Hill, NC, USA
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12
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Latza J, Otte M, Lindner T, Fischer DC, Bruhn S, Hollinski R, Warkentin M, Mittlmeier T, Müller-Hilke B. Interval Training Is Not Superior to Endurance Training With Respect to Bone Accrual of Ovariectomized Mice. Front Physiol 2020; 11:1096. [PMID: 33013466 PMCID: PMC7509202 DOI: 10.3389/fphys.2020.01096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/07/2020] [Indexed: 11/17/2022] Open
Abstract
Physical exercise is considered to delay bone loss associated with post-menopausal estrogen deficiency in women. However, the optimal training regimen for maximal bone accrual has not yet been defined. We, therefore, turned to ovariectomized (OVX) C57BL/6 mice and directly compared a low intensity endurance training on the treadmill to medium and high intensity interval trainings tailored to the individual performance limits. Trainings lasted 30 min each and were performed five times/week. After a 5-week training period, mice were sacrificed, and the hind legs were analyzed for assessment of (i) biomechanical stability (three-point bending test), (ii) bone microarchitecture [micro-computed tomography (μCT)], (iii) mineral apposition rate (MAR; histomorphometry), and (iv) muscle volume (MRI). Increased running speeds and quadriceps femoris muscle volumes in trained mice confirmed positive impacts on the cardiopulmonary system and myoinduction; however, none of the treadmill training regimens prevented ovariectomy induced bone loss. Our results provide evidence that treadmill training impacts differentially on the various members of the musculoskeletal unit and call for further experiments investigating frequency and duration of training regimens.
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Affiliation(s)
- Julia Latza
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | - Maresa Otte
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | - Tobias Lindner
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, Rostock, Germany
| | | | - Sven Bruhn
- Department of Exercise Science, Rostock University, Rostock, Germany
| | - Robin Hollinski
- Institute of Diagnostic and Interventional Radiology, Rostock University Medical Center, Rostock, Germany
| | - Mareike Warkentin
- Department of Material Science and Medical Engineering, Rostock University, Rostock, Germany
| | - Thomas Mittlmeier
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Rostock, Germany
| | - Brigitte Müller-Hilke
- Core Facility for Cell Sorting and Cell Analysis, Rostock University Medical Center, Rostock, Germany
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13
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Wallace IJ, Bendele AM, Riew G, Frank EH, Hung HH, Holowka NB, Bolze AS, Venable EM, Yegian AK, Dingwall HL, Carmody RN, Grodzinsky AJ, Lieberman DE. Physical inactivity and knee osteoarthritis in guinea pigs. Osteoarthritis Cartilage 2019; 27:1721-1728. [PMID: 31302235 DOI: 10.1016/j.joca.2019.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/13/2019] [Accepted: 07/01/2019] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate whether and how a sedentary lifestyle contributes to knee osteoarthritis (OA) incidence and severity. DESIGN An experiment was conducted using Hartley guinea pigs, an established idiopathic knee OA model. To simulate a sedentary lifestyle, growing animals (n = 18) were housed for 22 weeks in small cages that restricted their mobility, while another group of animals (n = 17) received daily treadmill exercise to simulate moderate physical activity. After the experiment, histological assessments, biochemical assays, and mechanical testing were conducted to compare tibial articular cartilage structure, strength, and degree of OA degeneration between sedentary and physically active animals. Groups were also compared based on body weight and composition, as well as gut microbial community composition assessed using fecal 16S rRNA gene sequencing. RESULTS Prevalence of knee OA was similar between sedentary and physically active animals, but severity of the disease (cartilage lesion depth) was substantially greater in the sedentary group (P = 0.02). In addition, during the experiment, sedentary animals developed cartilage with lower aggrecan quantity (P = 0.03) and accumulated more body weight (P = 0.005) and visceral adiposity (P = 0.007). Groups did not differ greatly, however, in terms of cartilage thickness, collagen quantity, or stiffness, nor in terms of muscle weight, subcutaneous adiposity, or gut microbial community composition. CONCLUSIONS Our findings indicate that a sedentary lifestyle promotes the development of knee OA, particularly by enhancing disease severity rather than risk of onset, and this potentially occurs through multiple pathways including by engendering growth of functionally deficient joint tissues and the accumulation of excess body weight and adiposity.
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Affiliation(s)
- I J Wallace
- Department of Human Evolutionary Biology, Harvard University, USA.
| | | | - G Riew
- Department of Human Evolutionary Biology, Harvard University, USA.
| | - E H Frank
- Center for Biomedical Engineering, Massachusetts Institute of Technology, USA.
| | - H-H Hung
- Center for Biomedical Engineering, Massachusetts Institute of Technology, USA.
| | - N B Holowka
- Department of Human Evolutionary Biology, Harvard University, USA.
| | - A S Bolze
- Department of Human Evolutionary Biology, Harvard University, USA.
| | - E M Venable
- Department of Human Evolutionary Biology, Harvard University, USA.
| | - A K Yegian
- Department of Human Evolutionary Biology, Harvard University, USA.
| | - H L Dingwall
- Department of Human Evolutionary Biology, Harvard University, USA.
| | - R N Carmody
- Department of Human Evolutionary Biology, Harvard University, USA.
| | - A J Grodzinsky
- Center for Biomedical Engineering, Massachusetts Institute of Technology, USA.
| | - D E Lieberman
- Department of Human Evolutionary Biology, Harvard University, USA.
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14
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Bourzac C, Bensidhoum M, Pallu S, Portier H. Use of adult mesenchymal stromal cells in tissue repair: impact of physical exercise. Am J Physiol Cell Physiol 2019; 317:C642-C654. [PMID: 31241985 PMCID: PMC6850997 DOI: 10.1152/ajpcell.00530.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 06/17/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023]
Abstract
Physical exercise (PE) has unquestionable beneficial effects on health, which likely extend into several organ-to-cell physiological processes. At the cell scale, endogenous mesenchymal stromal cells (MSCs) contribute to tissue repair, although their repair capacities may be insufficient in paucicellular or severely damaged tissues. For this reason, MSC transplantation holds great promise for tissue repair. With the goals of understanding if PE has beneficial effects on MSC biology and if PE potentiates their role in tissue repair, we reviewed literature reports regarding the effects of PE on MSC properties (specifically, proliferation, differentiation, and homing) and of a combination of PE and MSC transplantation on tissue repair (specifically neural, cartilage, and muscular tissues). Contradictory results have been reported; interpretation is complicated because various and different species, cell sources, and experimental protocols, specifically exercise programs, have been used. On the basis of these data, the effects of exercise on MSC proliferation and differentiation depend on exercise characteristics (type, intensity, duration, etc.) and on the characteristics of the tissue from which the MSCs were collected. For the in vitro studies, the level of strain (and other details of the mechanical stimulus), the time elapsed between the end of exposure to strain and MSC collection, the age of the donors, as well as the passage number at which the MSCs are evaluated also play a role. The combination of PE and MSC engraftment improves neural, cartilage, and muscular tissue recovery, but it is not clear whether the effects of MSCs and exercise are additive or synergistic.
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Affiliation(s)
- Celine Bourzac
- Université de Paris, CNRS, INSERM, Laboratoire de Biologie, Bioingenierie et Bioimagerie Osteoarticulaires (B3OA), Paris, France
- Ecole Nationale Vétérinaire d'Alfort, Laboratoire de Biologie, Bioingenierie et Bioimagerie Osteoarticulaires (B3OA), Maisons-Alfort, France
| | - Morad Bensidhoum
- Université de Paris, CNRS, INSERM, Laboratoire de Biologie, Bioingenierie et Bioimagerie Osteoarticulaires (B3OA), Paris, France
| | - Stephane Pallu
- Université de Paris, CNRS, INSERM, Laboratoire de Biologie, Bioingenierie et Bioimagerie Osteoarticulaires (B3OA), Paris, France
- Université d'Orléans, Le Collegium sciences et techniques (COST), Orléans, France
| | - Hugues Portier
- Université de Paris, CNRS, INSERM, Laboratoire de Biologie, Bioingenierie et Bioimagerie Osteoarticulaires (B3OA), Paris, France
- Université d'Orléans, Le Collegium sciences et techniques (COST), Orléans, France
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15
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Pagnotti GM, Styner M, Uzer G, Patel VS, Wright LE, Ness KK, Guise TA, Rubin J, Rubin CT. Combating osteoporosis and obesity with exercise: leveraging cell mechanosensitivity. Nat Rev Endocrinol 2019; 15:339-355. [PMID: 30814687 PMCID: PMC6520125 DOI: 10.1038/s41574-019-0170-1] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Osteoporosis, a condition of skeletal decline that undermines quality of life, is treated with pharmacological interventions that are associated with poor adherence and adverse effects. Complicating efforts to improve clinical outcomes, the incidence of obesity is increasing, predisposing the population to a range of musculoskeletal complications and metabolic disorders. Pharmacological management of obesity has yet to deliver notable reductions in weight and debilitating complications are rarely avoided. By contrast, exercise shows promise as a non-invasive and non-pharmacological method of regulating both osteoporosis and obesity. The principal components of exercise - mechanical signals - promote bone and muscle anabolism while limiting formation and expansion of fat mass. Mechanical regulation of bone and marrow fat might be achieved by regulating functions of differentiated cells in the skeletal tissue while biasing lineage selection of their common progenitors - mesenchymal stem cells. An inverse relationship between adipocyte versus osteoblast fate selection from stem cells is implicated in clinical conditions such as childhood obesity and increased marrow adiposity in type 2 diabetes mellitus, as well as contributing to skeletal frailty. Understanding how exercise-induced mechanical signals can be used to improve bone quality while decreasing fat mass and metabolic dysfunction should lead to new strategies to treat chronic diseases such as osteoporosis and obesity.
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Affiliation(s)
- Gabriel M Pagnotti
- School of Medicine, Division of Endocrinology, Indiana University, Indianapolis, IN, USA
| | - Maya Styner
- Department of Medicine, Division of Endocrinology and Metabolism, University of North Carolina, Chapel Hill, NC, USA
| | - Gunes Uzer
- College of Mechanical and Biomedical Engineering, Boise State University, Boise, ID, USA
| | - Vihitaben S Patel
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Laura E Wright
- School of Medicine, Division of Endocrinology, Indiana University, Indianapolis, IN, USA
| | - Kirsten K Ness
- Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Theresa A Guise
- School of Medicine, Division of Endocrinology, Indiana University, Indianapolis, IN, USA
| | - Janet Rubin
- Department of Medicine, Division of Endocrinology and Metabolism, University of North Carolina, Chapel Hill, NC, USA
| | - Clinton T Rubin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA.
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16
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Lüscher SH, Nocciolino LM, Pilot N, Pisani L, Ireland A, Rittweger J, Ferretti JL, Cointry GR, Capozza RF. Differences in the Cortical Structure of the Whole Fibula and Tibia Between Long-Distance Runners and Untrained Controls. Toward a Wider Conception of the Biomechanical Regulation of Cortical Bone Structure. Front Endocrinol (Lausanne) 2019; 10:833. [PMID: 31827461 PMCID: PMC6890608 DOI: 10.3389/fendo.2019.00833] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/14/2019] [Indexed: 11/29/2022] Open
Abstract
The cortical structure of human fibula varies widely throughout the bone suggesting a more selective adaptation to different mechanical environments with respect to the adjacent tibia. To test this hypothesis, serial-pQCT scans of the dominant fibulae and tibiae of 15/15 men/women chronically trained in long-distance running were compared with those of 15/15 untrained controls. When compared to controls, the fibulae of trained individuals had similar (distally) or lower (proximally) cortical area, similar moments of inertia (MI) for anterior-posterior bending (xMI) and lower for lateral bending (yMI) with a lower "shape-index" (yMI/xMI ratio) throughout, and higher resistance to buckling distally. These group differences were more evident in men and independent of group differences in bone mass. These results contrast with those observed in the tibia, where, as expected, structural indicators of bone strength were greater in trained than untrained individuals. Proximally, the larger lateral flexibility of runners' fibulae could improve the ability to store energy, and thereby contribute to fast-running optimization. Distally, the greater lateral fibular flexibility could reduce bending strength. The latter appears to have been compensated by a higher buckling strength. Assuming that these differences could be ascribed to training effects, this suggests that usage-derived strains in some bones may modify their relative structural resistance to different kinds of deformation in different regions, not only regarding strength, but also concerning other physiological roles of the skeleton.
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Affiliation(s)
- Sergio H. Lüscher
- Center for P-Ca Metabolism Studies (CEMFoC), National University of Rosario, Rosario, Argentina
| | - Laura M. Nocciolino
- Center for P-Ca Metabolism Studies (CEMFoC), National University of Rosario, Rosario, Argentina
- Unity of Musculoskeletal Biomechanical Studies (UDEBOM), Universidad del Gran Rosario, Rosario, Argentina
| | - Nicolás Pilot
- Unity of Musculoskeletal Biomechanical Studies (UDEBOM), Universidad del Gran Rosario, Rosario, Argentina
| | - Leonardo Pisani
- Unity of Musculoskeletal Biomechanical Studies (UDEBOM), Universidad del Gran Rosario, Rosario, Argentina
| | - Alex Ireland
- School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
- *Correspondence: Alex Ireland
| | - Jörn Rittweger
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Pediatrics and Adolescent Medicine, University of Cologne, Cologne, Germany
| | - José L. Ferretti
- Center for P-Ca Metabolism Studies (CEMFoC), National University of Rosario, Rosario, Argentina
| | - Gustavo R. Cointry
- Center for P-Ca Metabolism Studies (CEMFoC), National University of Rosario, Rosario, Argentina
| | - Ricardo F. Capozza
- Center for P-Ca Metabolism Studies (CEMFoC), National University of Rosario, Rosario, Argentina
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17
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Young JW, Jankord K, Saunders MM, Smith TD. Getting into Shape: Limb Bone Strength in Perinatal Lemur catta and Propithecus coquereli. Anat Rec (Hoboken) 2018; 303:250-264. [PMID: 30548126 DOI: 10.1002/ar.24045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 05/03/2018] [Accepted: 05/14/2018] [Indexed: 01/09/2023]
Abstract
Functional studies of skeletal anatomy are predicated on the fundamental assumption that form will follow function. For instance, previous studies have shown that the femora of specialized leaping primates are more robust than those of more generalized primate quadrupeds. Are such differences solely a plastic response to differential loading patterns during postnatal life, or might they also reflect more canalized developmental mechanisms present at birth? Here, we show that perinatal Lemur catta, an arboreal/terrestrial quadruped, have less robust femora than perinatal Propithecus coquereli, a closely related species specialized for vertical clinging and leaping (a highly unusual locomotor mode in which the hindlimbs are used to launch the animal between vertical tree trunks). These results suggest that functional differences in long bone cross-sectional dimensions are manifest at birth, belying simple interpretations of adult postcranial form as a direct record of loading patterns during postnatal life. Despite these significant differences in bone robusticity, we find that hindlimb bone mineralization, material properties, and measures of whole-bone strength generally overlap in perinatal L. catta and P. coquereli, indicating little differentiation in postcranial maturity at birth despite known differences in the pace of craniodental development between the species. In a broader perspective, our results likely reflect evolution acting during prenatal ontogeny. Even though primates are notable for relatively prolonged gestation and postnatal parental care, neonates are not buffered from selection, perhaps especially in the unpredictable and volatile environment of Madagascar. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 303:250-264, 2020. © 2018 American Association for Anatomy.
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Affiliation(s)
- Jesse W Young
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED), Rootstown, Ohio, 44272
| | - Kathryn Jankord
- School of Physical Therapy, Slippery Rock University, Slippery Rock, Pennsylvania, 16057
| | - Marnie M Saunders
- Department of Biomedical Engineering, The University of Akron, Akron, Ohio, 44325
| | - Timothy D Smith
- School of Physical Therapy, Slippery Rock University, Slippery Rock, Pennsylvania, 16057.,Department of Anthropology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213
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18
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Tsegai ZJ, Skinner MM, Pahr DH, Hublin JJ, Kivell TL. Ontogeny and variability of trabecular bone in the chimpanzee humerus, femur and tibia. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 167:713-736. [DOI: 10.1002/ajpa.23696] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/22/2018] [Accepted: 07/23/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Zewdi J. Tsegai
- Department of Human Evolution; Max Planck Institute for Evolutionary Anthropology; Leipzig Germany
| | - Matthew M. Skinner
- Skeletal Biology Research Center; School of Anthropology and Conservation, University of Kent; Canterbury United Kingdom
- Department of Human Evolution; Max Planck Institute for Evolutionary Anthropology; Leipzig Germany
| | - Dieter H. Pahr
- Institute for Lightweight Design and Structural Biomechanics; Vienna University of Technology; Wien Austria
| | - Jean-Jacques Hublin
- Department of Human Evolution; Max Planck Institute for Evolutionary Anthropology; Leipzig Germany
| | - Tracy L. Kivell
- Skeletal Biology Research Center; School of Anthropology and Conservation, University of Kent; Canterbury United Kingdom
- Department of Human Evolution; Max Planck Institute for Evolutionary Anthropology; Leipzig Germany
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19
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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: 23] [Impact Index Per Article: 3.8] [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.
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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
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20
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Using modern human cortical bone distribution to test the systemic robusticity hypothesis. J Hum Evol 2018; 119:64-82. [DOI: 10.1016/j.jhevol.2018.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/07/2018] [Accepted: 03/08/2018] [Indexed: 11/19/2022]
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21
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Tsegai ZJ, Skinner MM, Pahr DH, Hublin J, Kivell TL. Systemic patterns of trabecular bone across the human and chimpanzee skeleton. J Anat 2018; 232:641-656. [PMID: 29344941 PMCID: PMC5835784 DOI: 10.1111/joa.12776] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2017] [Indexed: 12/18/2022] Open
Abstract
Aspects of trabecular bone architecture are thought to reflect regional loading of the skeleton, and thus differ between primate taxa with different locomotor and postural modes. However, there are several systemic factors that affect bone structure that could contribute to, or be the primary factor determining, interspecific differences in bone structure. These systemic factors include differences in genetic regulation, sensitivity to loading, hormone levels, diet, and activity levels. Improved understanding of inter-/intraspecific variability, and variability across the skeleton of an individual, is required to interpret properly potential functional signals present within trabecular structure. Using a whole-region method of analysis, we investigated trabecular structure throughout the skeleton of humans and chimpanzees. Trabecular bone volume fraction (BV/TV), degree of anisotropy (DA) and trabecular thickness (Tb.Th) were quantified from high resolution micro-computed tomographic scans of the humeral and femoral head, third metacarpal and third metatarsal head, distal tibia, talus and first thoracic vertebra. We found that BV/TV is, in most anatomical sites, significantly higher in chimpanzees than in humans, suggesting a systemic difference in trabecular structure unrelated to local loading regime. Differences in BV/TV between the forelimb and hindlimb did not clearly reflect differences in locomotor loading in the study taxa. There were no clear systemic differences between the taxa in DA and, as such, this parameter might reflect function and relate to differences in joint loading. This systemic approach reveals both the pattern of variability across the skeleton and between taxa, and helps identify those features of trabecular structure that may relate to joint function.
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Affiliation(s)
- Zewdi J. Tsegai
- Department of Human EvolutionMax Planck Institute for Evolutionary AnthropologyLeipzigGermany
| | - Matthew M. Skinner
- Department of Human EvolutionMax Planck Institute for Evolutionary AnthropologyLeipzigGermany
- Skeletal Biology Research CentreSchool of Anthropology and ConservationUniversity of KentCanterburyUK
| | - Dieter H. Pahr
- Institute of Lightweight Design and Structural BiomechanicsVienna University of TechnologyViennaAustria
| | - Jean‐Jacques Hublin
- Department of Human EvolutionMax Planck Institute for Evolutionary AnthropologyLeipzigGermany
| | - Tracy L. Kivell
- Department of Human EvolutionMax Planck Institute for Evolutionary AnthropologyLeipzigGermany
- Skeletal Biology Research CentreSchool of Anthropology and ConservationUniversity of KentCanterburyUK
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22
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Yu K, Sellman DP, Bahraini A, Hagan ML, Elsherbini A, Vanpelt KT, Marshall PL, Hamrick MW, McNeil A, McNeil PL, McGee-Lawrence ME. Mechanical loading disrupts osteocyte plasma membranes which initiates mechanosensation events in bone. J Orthop Res 2018; 36:653-662. [PMID: 28755471 PMCID: PMC5788741 DOI: 10.1002/jor.23665] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/24/2017] [Indexed: 02/04/2023]
Abstract
Osteocytes sense loading in bone, but their mechanosensation mechanisms remain poorly understood. Plasma membrane disruptions (PMD) develop with loading under physiological conditions in many cell types (e.g., myocytes, endothelial cells). These PMD foster molecular flux across cell membranes that promotes tissue adaptation, but this mechanosensation mechanism had not been explored in osteocytes. Our goal was to investigate whether PMD occur and initiate consequent mechanotransduction in osteocytes during physiological loading. We found that osteocytes experience PMD during in vitro (fluid flow) and in vivo (treadmill exercise) mechanical loading, in proportion to the level of stress experienced. In fluid flow studies, osteocyte PMD preferentially formed with rapid as compared to gradual application of loading. In treadmill studies, osteocyte PMD increased with loading in weight bearing locations (tibia), but this trend was not seen in non-weight bearing locations (skull). PMD initiated osteocyte mechanotransduction including calcium signaling and expression of c-fos, and repair rates of these PMD could be enhanced or inhibited pharmacologically to alter downstream mechanotransduction and osteocyte survival. PMD may represent a novel mechanosensation pathway in bone and a target for modifying skeletal adaptation signaling in osteocytes. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:653-662, 2018.
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Affiliation(s)
- Kanglun Yu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - David P. Sellman
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Anoosh Bahraini
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Mackenzie L. Hagan
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Ahmed Elsherbini
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Kayce T. Vanpelt
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Peyton L. Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Mark W. Hamrick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Anna McNeil
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Paul L. McNeil
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
| | - Meghan E. McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
- Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, 1120 15 St, Augusta, GA
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Rubin J, Styner M, Uzer G. Physical Signals May Affect Mesenchymal Stem Cell Differentiation via Epigenetic Controls. Exerc Sport Sci Rev 2018; 46:42-47. [PMID: 28795956 DOI: 10.1249/jes.0000000000000129] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Marrow mesenchymal stem cells supply bone osteoblasts and adipocytes. Exercise effects to increase bone and decrease fat involve transfer of signals from the cytoplasm into the nucleus to regulate gene expression. We propose that exercise control of stem cell fate relies on structural connections that terminate in the nucleus and involve intranuclear actin structures that regulate epigenetic gene expression.
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Affiliation(s)
- Janet Rubin
- Department of Medicine, University of North Carolina, Chapel Hill, NC
| | - Maya Styner
- Department of Medicine, University of North Carolina, Chapel Hill, NC
| | - Gunes Uzer
- Department of Medicine, University of North Carolina, Chapel Hill, NC
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Mogil RJ, Kaste SC, Ferry RJ, Hudson MM, Mulrooney DA, Howell CR, Partin RE, Srivastava DK, Robison LL, Ness KK. Effect of Low-Magnitude, High-Frequency Mechanical Stimulation on BMD Among Young Childhood Cancer Survivors: A Randomized Clinical Trial. JAMA Oncol 2017; 2:908-14. [PMID: 26967465 DOI: 10.1001/jamaoncol.2015.6557] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Bone accrual during youth is critical to establish sufficient strength for lifelong skeletal health. Children with cancer may develop low bone mineral density (BMD) any time before or after diagnosis. OBJECTIVE To evaluate the ability of low-magnitude, high-frequency mechanical stimulation to enhance BMD among childhood cancer survivors. DESIGN, SETTING, AND PARTICIPANTS Double-blind randomized clinical trial conducted at St Jude Children's Research Hospital from June 1, 2010, to January 22, 2013, using cancer survivors, ages 7 to 17 years, who were previously treated at St Jude Children's Research Hospital, were in remission, and at least 5 years from diagnosis, with whole-body or lumbar spine BMD z scores of -1.0 or lower. Participants were randomized (stratified by sex and Tanner stage) to either a placebo device or low-magnitude, high-frequency mechanical stimulation device, which was used at home. INTERVENTIONS Placebo or low-magnitude, high-frequency mechanical stimulation (0.3 g; 32-37 Hz) for 2 sessions lasting 10 minutes each, 7 days per week for 1 year. All participants were prescribed daily cholecalciferol (vitamin D) and calcium. MAIN OUTCOMES AND MEASURES Changes in areal and volumetric BMD and bone biomarkers were compared by analysis of variance, adjusted for strata. RESULTS Of the 65 participants, 32 were randomized to the intervention group (mean [SD] age was 13.6 [3.7] years, 18 [56.2%] were male, and 27 [84.4%] were white), and 33 were randomized to the placebo group (mean [SD] age was 13.6 [2.9] years, 17 [51.5%] were male, and 26 [78.8%] were white). Forty-eight participants completed the trial, 22 in the intervention group and 26 in the placebo group with median adherence of 70.1% for intervention and 63.7% for placebo groups. With intention-to-treat analysis, mean (SD) whole-body BMD z score by dual x-ray absorptiometry improved by 0.25 (0.78) in the intervention (n = 22), but decreased by -0.19 (0.79) in the placebo group (n = 26, P = .05). Circulating osteocalcin at 12 months correlated with change in total body BMD (r = 0.35, P = .02). Tibial trabecular bone among participants completing 70% or more of the prescribed sessions increased by a mean of 11.2% (95% CI, 5.2 to 17.2%) compared with those completing less than 70% who decreased by a mean of -1.3% (95% CI, -7.3 to 4.7%; P = .02). Change in circulating receptor activator of nuclear factor κ-B ligand was higher in the intervention than in the placebo group (0.06 [0.16] vs -0.04 [0.17] pmol/L) (P = .04). CONCLUSIONS AND RELEVANCE Pediatric cancer survivors with low BMD may benefit from low-magnitude, high-frequency mechanical stimulation as a novel and safe intervention to optimize peak bone mass during youth, alone or in conjunction with other therapies. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01010230.
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Affiliation(s)
- Rona J Mogil
- Department of Epidemiology and Cancer Control, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Sue C Kaste
- Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, Tennessee3Department of Radiology, University of Tennessee Health Science Center, Memphis
| | - Robert J Ferry
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis5Department of Psychology, University of Memphis, Memphis, Tennessee
| | - Melissa M Hudson
- Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Daniel A Mulrooney
- Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Carrie R Howell
- Department of Epidemiology and Cancer Control, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Robyn E Partin
- Department of Epidemiology and Cancer Control, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Deo K Srivastava
- Department of Biostatistics, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Leslie L Robison
- Department of Epidemiology and Cancer Control, St Jude Children's Research Hospital, Memphis, Tennessee
| | - Kirsten K Ness
- Department of Epidemiology and Cancer Control, St Jude Children's Research Hospital, Memphis, Tennessee8Department of Pediatric Medicine, St Jude Children's Research Hospital, Memphis, Tennessee
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Liu SY, He YB, Deng SY, Zhu WT, Xu SY, Ni GX. Exercise affects biological characteristics of mesenchymal stromal cells derived from bone marrow and adipose tissue. INTERNATIONAL ORTHOPAEDICS 2017; 41:1199-1209. [PMID: 28364139 DOI: 10.1007/s00264-017-3441-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 03/09/2017] [Indexed: 02/05/2023]
Abstract
Both bone marrow mesenchymal stromal cells (BMSCs) and adipose-derived mesenchymal stromal cells (ADSCs) are good sources for tissue engineering. To maximize therapeutic efficacy of MSCs, an appropriate source of MSCs should be selected according to their own inherent characteristics for future clinical application. Hence, this study was conducted to compare proliferative, differential and antiapoptosis abilities of both MSCs derived from exercised and sedentary rats under normal and hypoxia/serum deprivation conditions (H/SD). Our results showed that exercise may enhance proliferative ability and decrease adipogenic ability of BMSCs and ADSCs. However, positive effect of exercise on osteogenesis was only observed for BMSCs in either environment. Little effect was observed on the antiapoptotic ability of both MSC types. It was also suggested that biological characteristics of both types were partly changed. It is therefore believed that BMSCs derived from exercised rat on early passage may be a good cell source for bone tissue engineering.
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Affiliation(s)
- Sheng-Yao Liu
- Department of Orthopeadics and Traumatology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue (N), Guangzhou, 510515, China
| | - Yong-Bin He
- Department of Orthopeadics and Traumatology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue (N), Guangzhou, 510515, China
| | - Song-Yun Deng
- Department of Orthopeadics and Traumatology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue (N), Guangzhou, 510515, China
| | - Wen-Ting Zhu
- Biomaterial Research Center, School of pharmaceutical sciences, Southern Medical University, 1838 Guangzhou Avenue (N), Guangzhou, 510515, China
| | - Shao-Yong Xu
- Department of Orthopeadics and Traumatology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue (N), Guangzhou, 510515, China
| | - Guo-Xin Ni
- Department of Orthopeadics and Traumatology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue (N), Guangzhou, 510515, China.
- Department of Rehabilitation Medicine, First Affiliated Hospital, Fujian Medical University, 20 Chazhong Road, Fuzhou, 350005, China.
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Quantitative Assessment of Optimal Bone Marrow Site for the Isolation of Porcine Mesenchymal Stem Cells. Stem Cells Int 2017; 2017:1836960. [PMID: 28539939 PMCID: PMC5429955 DOI: 10.1155/2017/1836960] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/28/2017] [Indexed: 12/13/2022] Open
Abstract
Background. One of the most plentiful sources for MSCs is the bone marrow; however, it is unknown whether MSC yield differs among different bone marrow sites. In this study, we quantified cellular yield and evaluated resident MSC population from five bone marrow sites in the porcine model. In addition, we assessed the feasibility of a commercially available platelet concentrator (Magellan® MAR01™ Arteriocyte Medical Systems, Hopkinton, MA) as a bedside stem cell concentration device. Methods. Analyses of bone marrow aspirate (BMA) and concentrated bone marrow aspirate (cBMA) included bone marrow volume, platelet and nucleated cell yield, colony-forming unit fibroblast (CFU-F) number, flow cytometry, and assessment of differentiation potential. Results. Following processing, the concentration of platelets and nucleated cells significantly increased but was not significantly different between sites. The iliac crest had significantly less bone marrow volume; however, it yielded significantly more CFUs compared to the other bone marrow sites. Culture-expanded cells from all tested sites expressed high levels of MSC surface markers and demonstrated adipogenic and osteogenic differentiation potential. Conclusions. All anatomical bone marrow sites contained MSCs, but the iliac crest was the most abundant source of MSCs. Additionally, the Magellan can function effectively as a bedside stem cell concentrator.
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27
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Koenen K, Knepper I, Klodt M, Osterberg A, Stratos I, Mittlmeier T, Histing T, Menger MD, Vollmar B, Bruhn S, Müller-Hilke B. Sprint Interval Training Induces A Sexual Dimorphism but does not Improve Peak Bone Mass in Young and Healthy Mice. Sci Rep 2017; 7:44047. [PMID: 28303909 PMCID: PMC5355982 DOI: 10.1038/srep44047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/03/2017] [Indexed: 12/17/2022] Open
Abstract
Elevated peak bone mass in early adulthood reduces the risk for osteoporotic fractures at old age. As sports participation has been correlated with elevated peak bone masses, we aimed to establish a training program that would efficiently stimulate bone accrual in healthy young mice. We combined voluntary treadmill running with sprint interval training modalities that were tailored to the individual performance limits and were of either high or intermediate intensity. Adolescent male and female STR/ort mice underwent 8 weeks of training before the hind legs were analyzed for cortical and trabecular bone parameters and biomechanical strength. Sprint interval training led to increased running speeds, confirming an efficient training. However, males and females responded differently. The males improved their running speeds in response to intermediate intensities only and accrued cortical bone at the expense of mechanical strength. High training intensities induced a significant loss of trabecular bone. The female bones showed neither adverse nor beneficial effects in response to either training intensities. Speculations about the failure to improve geometric alongside mechanical bone properties include the possibility that our training lacked sufficient axial loading, that high cardio-vascular strains adversely affect bone growth and that there are physiological limits to bone accrual.
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Affiliation(s)
- Kathrin Koenen
- Institute for Immunology, Rostock University Medical Center, Germany
| | - Isabell Knepper
- Institute for Immunology, Rostock University Medical Center, Germany
| | - Madlen Klodt
- Institute for Immunology, Rostock University Medical Center, Germany
| | - Anja Osterberg
- Institute for Immunology, Rostock University Medical Center, Germany
| | - Ioannis Stratos
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Germany
| | - Thomas Mittlmeier
- Department for Trauma, Hand and Reconstructive Surgery, Rostock University Medical Center, Germany
| | - Tina Histing
- Institute for Clinical and Experimental Surgery, University of Saarland, Homburg, Saar, Germany
| | - Michael D Menger
- Institute for Clinical and Experimental Surgery, University of Saarland, Homburg, Saar, Germany
| | - Brigitte Vollmar
- Institute for Experimental Surgery, Rostock University Medical Center, Germany
| | - Sven Bruhn
- Department of Exercise Sciences, Rostock University, Germany
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Wallace IJ, Winchester JM, Su A, Boyer DM, Konow N. Physical activity alters limb bone structure but not entheseal morphology. J Hum Evol 2017; 107:14-18. [PMID: 28526286 DOI: 10.1016/j.jhevol.2017.02.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 02/08/2017] [Accepted: 02/10/2017] [Indexed: 12/26/2022]
Abstract
Studies of ancient human skeletal remains frequently proceed from the assumption that individuals with robust limb bones and/or rugose, hypertrophic entheses can be inferred to have been highly physically active during life. Here, we experimentally test this assumption by measuring the effects of exercise on limb bone structure and entheseal morphology in turkeys. Growing females were either treated with a treadmill-running regimen for 10 weeks or served as controls. After the experiment, femoral cortical and trabecular bone structure were quantified with μCT in the mid-diaphysis and distal epiphysis, respectively, and entheseal morphology was quantified in the lateral epicondyle. The results indicate that elevated levels of physical activity affect limb bone structure but not entheseal morphology. Specifically, animals subjected to exercise displayed enhanced diaphyseal and trabecular bone architecture relative to controls, but no significant difference was detected between experimental groups in entheseal surface topography. These findings suggest that diaphyseal and trabecular structure are more reliable proxies than entheseal morphology for inferring ancient human physical activity levels from skeletal remains.
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Affiliation(s)
- Ian J Wallace
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Julia M Winchester
- Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Anne Su
- School of Health Sciences, Cleveland State University, Cleveland, OH 44115, USA
| | - Doug M Boyer
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Nicolai Konow
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA; Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA.
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29
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Yang H, Embry RE, Main RP. Effects of Loading Duration and Short Rest Insertion on Cancellous and Cortical Bone Adaptation in the Mouse Tibia. PLoS One 2017; 12:e0169519. [PMID: 28076363 PMCID: PMC5226737 DOI: 10.1371/journal.pone.0169519] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 12/19/2016] [Indexed: 11/19/2022] Open
Abstract
The skeleton's osteogenic response to mechanical loading can be affected by loading duration and rest insertion during a series of loading events. Prior animal loading studies have shown that the cortical bone response saturates quickly and short rest insertions between load cycles can enhance cortical bone formation. However, it remains unknown how loading duration and short rest insertion affect load-induced osteogenesis in the mouse tibial compressive loading model, and particularly in cancellous bone. To address this issue, we applied cyclic loading (-9 N peak load; 4 Hz) to the tibiae of three groups of 16 week-old female C57BL/6 mice for two weeks, with a different number of continuous load cycles applied daily to each group (36, 216 and 1200). A fourth group was loaded under 216 daily load cycles with a 10 s rest insertion after every fourth cycle. We found that as few as 36 load cycles per day were able to induce osteogenic responses in both cancellous and cortical bone. Furthermore, while cortical bone area and thickness continued to increase through 1200 cycles, the incremental increase in the osteogenic response decreased as load number increased, indicating a reduced benefit of the increasing number of load cycles. In the proximal metaphyseal cancellous bone, trabecular thickness increased with load up to 216 cycles. We also found that insertion of a 10 s rest between load cycles did not improve the osteogenic response of the cortical or cancellous tissues compared to continuous loading in this model given the age and sex of the mice and the loading parameters used here. These results suggest that relatively few load cycles (e.g. 36) are sufficient to induce osteogenic responses in both cortical and cancellous bone in the mouse tibial loading model. Mechanistic studies using the mouse tibial loading model to examine bone formation and skeletal mechanobiology could be accomplished with relatively few load cycles.
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Affiliation(s)
- Haisheng Yang
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Rachel E. Embry
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Russell P. Main
- Musculoskeletal Biology and Mechanics Lab, Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail:
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30
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Jónsson JE, Afton AD. Do foraging methods in winter affect morphology during growth in juvenile snow geese? Ecol Evol 2016; 6:7656-7670. [PMID: 30128119 PMCID: PMC6093151 DOI: 10.1002/ece3.2481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/19/2016] [Accepted: 08/22/2016] [Indexed: 11/13/2022] Open
Abstract
Physical exertion during growth can affect ultimate size and density of skeletal structures. Such changes from different exercise regimes may explain morphological differences between groups, such as those exhibited by lesser snow geese (Chen caerulescens caerulescens; hereafter snow geese) foraging in southwest Louisiana. In rice‐prairie habitats (hereafter rice‐prairies), snow geese bite off or graze aboveground vegetation, whereas they dig or grub for subterranean plant parts in adjacent coastal marshes. Grubbing involves considerably more muscular exertion than does grazing. Thus, we hypothesized that rates of bone formation and growth would be lower for juveniles wintering in rice‐prairies than those in coastal marshes, resulting in smaller bill and skull features at adulthood. First, we tested this exertion hypothesis by measuring bills, skulls, and associated musculature from arrival to departure (November–February) in both habitats in southwest Louisiana, using both banded birds and collected specimens. Second, we used the morphological data to test an alternative hypothesis, which states that smaller bill dimensions in rice‐prairies evolved because of hybridization with Ross's geese (C. rossii). Under the exertion hypothesis, we predicted that bill and skull bones of juveniles would grow at different rates between habitats. However, we found that bill and skull bones of juveniles grew similarly between habitats, thus failing to support the exertion hypothesis. Morphometrics were more likely to differ by sex or change with sampling date than to differ by habitat. We predicted that significant, consistent skewness toward smaller birds could indicate hybridization with Ross's geese, but no skewness was observed in our morphological data, which fails to support the hybridization hypothesis. Further research is needed to clarify whether snow geese wintering in Louisiana represent a single polymorphic population that segregates into individually preferred habitats, which we believe at present to be more likely as an explanation than two ecologically and spatially distinct morphotypes.
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Affiliation(s)
- Jón Einar Jónsson
- Research Centre at Snæfellsnes University of Iceland Stykkishólmur Iceland
| | - Alan D Afton
- U.S. Geological Survey Louisiana Cooperative Fish and Wildlife Research Unit Louisiana State University Baton Rouge LA USA
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Pagnotti GM, Chan ME, Adler BJ, Shroyer KR, Rubin J, Bain SD, Rubin CT. Low intensity vibration mitigates tumor progression and protects bone quantity and quality in a murine model of myeloma. Bone 2016; 90:69-79. [PMID: 27262776 PMCID: PMC4970889 DOI: 10.1016/j.bone.2016.05.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 05/13/2016] [Accepted: 05/31/2016] [Indexed: 01/18/2023]
Abstract
Myeloma facilitates destruction of bone and marrow. Since physical activity encourages musculoskeletal preservation we evaluated whether low-intensity vibration (LIV), a means to deliver mechanical signals, could protect bone and marrow during myeloma progression. Immunocompromised-mice (n=25) were injected with human-myeloma cells, while 8 (AC) were saline-injected. Myeloma-injected mice (LIV; n=13) were subjected to daily-mechanical loading (15min/d; 0.3g @ 90Hz) while 12 (MM) were sham-handled. At 8w, femurs had 86% less trabecular bone volume fraction (BV/TV) in MM than in AC, yet only a 21% decrease in LIV was observed in comparison to AC, reflecting a 76% increase versus MM. Cortical BV was 21% and 15% lower in MM and LIV, respectively, than in AC; LIV showing 30% improvement over MM. Similar outcomes were observed in the axial skeleton, showing a 35% loss in MM with a 27% improved retention of bone in the L5 of LIV-treated mice as compared to MM. Transcortical-perforations in the femur from myeloma-induced osteolysis were 9× higher in MM versus AC, reduced by 57% in LIV. Serum-TRACP5b, 61% greater in MM versus AC, rose by 33% in LIV compared to AC, a 45% reduction in activity when compared to MM. Histomorphometric analyses of femoral trabecular bone demonstrated a 70% elevation in eroded surfaces of MM versus AC, while measures in LIV were 58% below those in MM. 72% of marrow in the femur of MM mice contained tumor, contrasted by a 31% lower burden in LIV. MM mice (42%) presented advanced-stage necrosis of tibial marrow while present in just 8% of LIV. Myeloma infiltration inversely correlated to measures of bone quality, while LIV slowed the systemic, myeloma-associated decline in bone quality and inhibited tumor progression through the hindlimbs.
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Affiliation(s)
- Gabriel M Pagnotti
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - M Ete Chan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - Benjamin J Adler
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States
| | - Kenneth R Shroyer
- Department of Pathology, Stony Brook University, Stony Brook, NY 11794-2580, United States
| | - Janet Rubin
- Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Steven D Bain
- Department of Orthopedics & Sports Medicine, University of Washington, Seattle, WA 98104-2499, United States
| | - Clinton T Rubin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, United States.
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32
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Stephens NB, Kivell TL, Gross T, Pahr DH, Lazenby RA, Hublin JJ, Hershkovitz I, Skinner MM. Trabecular architecture in the thumb of Pan and Homo: implications for investigating hand use, loading, and hand preference in the fossil record. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 161:603-619. [PMID: 27500902 DOI: 10.1002/ajpa.23061] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 06/14/2016] [Accepted: 07/24/2016] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Humans display an 85-95% cross-cultural right-hand bias in skilled tasks, which is considered a derived behavior because such a high frequency is not reported in wild non-human primates. Handedness is generally considered to be an evolutionary byproduct of selection for manual dexterity and augmented visuo-cognitive capabilities within the context of complex stone tool manufacture/use. Testing this hypothesis requires an understanding of when appreciable levels of right dominant behavior entered the fossil record. Because bone remodels in vivo, skeletal asymmetries are thought to reflect greater mechanical loading on the dominant side, but incomplete preservation of external morphology and ambiguities about past loading environments complicate interpretations. We test if internal trabecular bone is capable of providing additional information by analyzing the thumb of Homo sapiens and Pan. MATERIALS AND METHODS We assess trabecular structure at the distal head and proximal base of paired (left/right) first metacarpals using micro-CT scans of Homo sapiens (n = 14) and Pan (n = 9). Throughout each epiphysis we quantify average and local bone volume fraction (BV/TV), degree of anisotropy (DA), and elastic modulus (E) to address bone volume patterning and directional asymmetry. RESULTS We find a right directional asymmetry in H. sapiens consistent with population-level handedness, but also report a left directional asymmetry in Pan that may be the result of postural and/or locomotor loading. CONCLUSION We conclude that trabecular bone is capable of detecting right/left directional asymmetry, but suggest coupling studies of internal structure with analyses of other skeletal elements and cortical bone prior to applications in the fossil record.
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Affiliation(s)
- Nicholas B Stephens
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany
| | - Tracy L Kivell
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany.,Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, CT2 7NR, United Kingdom
| | - Thomas Gross
- Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, A-1060 Vienna, Getreidemarkt 9/BE, Vienna, Austria
| | - Dieter H Pahr
- Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, A-1060 Vienna, Getreidemarkt 9/BE, Vienna, Austria
| | - Richard A Lazenby
- Department of Anthropology, University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada, V2N 4Z9
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany
| | - Israel Hershkovitz
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Matthew M Skinner
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany.,Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, CT2 7NR, United Kingdom
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Krishnamoorthy D, Frechette DM, Adler BJ, Green DE, Chan ME, Rubin CT. Marrow adipogenesis and bone loss that parallels estrogen deficiency is slowed by low-intensity mechanical signals. Osteoporos Int 2016; 27:747-56. [PMID: 26323329 DOI: 10.1007/s00198-015-3289-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 08/11/2015] [Indexed: 01/23/2023]
Abstract
UNLABELLED Ovariectomized mice were used to assess the ability of low-intensity vibrations to protect bone microarchitecture and marrow composition. Results indicate that low-intensity vibrations (LIV), introduced 2 weeks postsurgery, slows marrow adipogenesis in OVX mice but does not restore the bone within the period studied. However, immediate application of LIV partially protects quality. INTRODUCTION The aim of this study was to evaluate consequences of estrogen depletion on bone marrow (BM) phenotype and bone microarchitecture, and effects of mechanical signals delivered as LIV on modulating these changes. METHODS LIV (0.3 g, 90 Hz) was applied to C57BL/6 mice immediately following ovariectomy or 2 weeks postestrogen withdrawal for 2 (ST-LIV) or 6 weeks (LT-LIV), respectively. Sham-operated age-matched controls (ST-AC, LT-AC) and ovariectomized controls (ST-OVX, LT-OVX) received sham LIV treatment. Bone microstructure was evaluated through μCT and BM adipogenesis through histomorphometry, serum markers, and genes expression analysis. RESULTS LT-OVX increased BM adipogenesis relative to LT-AC (+136 %, p ≤ 0.05), while LT-LIV introduced for 6w suppressed this adipose encroachment (-55 %, p ≤ 0.05). In parallel with the fatty marrow, LT-OVX showed a marked loss of trabecular bone, -40 % (p ≤ 0.05) in the first 2 weeks following ovariectomy compared to LT-AC. Application of LT-LIV for 6w following this initial 2w bone loss failed to restore the lost trabeculae but did initiate an anabolic response as indicated by increased serum alkaline phosphatase (+26 %, p ≤ 0.05). In contrast, application of LIV immediately following ovariectomy was more efficacious in the protection of trabecular bone, with a +29 % (p > 0.05) greater BV/TV compared to ST-OVX at the 2w time period. CONCLUSIONS LIV can mitigate adipocyte accumulation in OVX marrow and protect it by favoring osteoblastogenesis over adipogenesis. These data also emphasize the rapidity of bone loss with OVX and provide perspective in the timing of treatments for postmenopausal osteoporosis where sooner is better than later.
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Affiliation(s)
- D Krishnamoorthy
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - D M Frechette
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - B J Adler
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - D E Green
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - M E Chan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - C T Rubin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA.
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Pagnotti GM, Styner M. Exercise Regulation of Marrow Adipose Tissue. Front Endocrinol (Lausanne) 2016; 7:94. [PMID: 27471493 PMCID: PMC4943947 DOI: 10.3389/fendo.2016.00094] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 07/04/2016] [Indexed: 12/20/2022] Open
Abstract
Despite association with low bone density and skeletal fractures, marrow adipose tissue (MAT) remains poorly understood. The marrow adipocyte originates from the mesenchymal stem cell (MSC) pool that also gives rise to osteoblasts, chondrocytes, and myocytes, among other cell types. To date, the presence of MAT has been attributed to preferential biasing of MSC into the adipocyte rather than osteoblast lineage, thus negatively impacting bone formation. Here, we focus on understanding the physiology of MAT in the setting of exercise, dietary interventions, and pharmacologic agents that alter fat metabolism. The beneficial effect of exercise on musculoskeletal strength is known: exercise induces bone formation, encourages growth of skeletally supportive tissues, inhibits bone resorption, and alters skeletal architecture through direct and indirect effects on a multiplicity of cells involved in skeletal adaptation. MAT is less well studied due to the lack of reproducible quantification techniques. In recent work, osmium-based 3D quantification shows a robust response of MAT to both dietary and exercise intervention in that MAT is elevated in response to high-fat diet and can be suppressed following daily exercise. Exercise-induced bone formation correlates with suppression of MAT, such that exercise effects might be due to either calorie expenditure from this depot or from mechanical biasing of MSC lineage away from fat and toward bone, or a combination thereof. Following treatment with the anti-diabetes drug rosiglitazone - a PPARγ-agonist known to increase MAT and fracture risk - mice demonstrate a fivefold higher femur MAT volume compared to the controls. In addition to preventing MAT accumulation in control mice, exercise intervention significantly lowers MAT accumulation in rosiglitazone-treated mice. Importantly, exercise induction of trabecular bone volume is unhindered by rosiglitazone. Thus, despite rosiglitazone augmentation of MAT, exercise significantly suppresses MAT volume and induces bone formation. That exercise can both suppress MAT volume and increase bone quantity, notwithstanding the skeletal harm induced by rosiglitazone, underscores exercise as a powerful regulator of bone remodeling, encouraging marrow stem cells toward the osteogenic lineage to fulfill an adaptive need for bone formation. Thus, exercise represents an effective strategy to mitigate the deleterious effects of overeating and iatrogenic etiologies on bone and fat.
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Affiliation(s)
- Gabriel M. Pagnotti
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Maya Styner
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
- *Correspondence: Maya Styner,
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