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Lee S, Shin YA, Cho J, Park DH, Kim C. Moderate-Intensity Exercise Preserves Bone Mineral Density and Improves Femoral Trabecular Bone Microarchitecture in Middle-Aged Mice. J Bone Metab 2022; 29:103-111. [PMID: 35718927 PMCID: PMC9208899 DOI: 10.11005/jbm.2022.29.2.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 04/07/2022] [Indexed: 11/25/2022] Open
Abstract
Background Aging leads to significant bone loss and elevated osteoporosis risk. Exercise slows age-related bone loss; however, the effects of various moderate-intensity exercise training volumes on bone metabolism remain unclear. This study aimed to determine the degree to which different volumes of moderate-intensity aerobic exercise training influence bone mineral density (BMD), bone mineral content (BMC), femoral trabecular bone microarchitecture, and cortical bone in middle-aged mice. Methods Twenty middle-aged male C57BL/6 mice were randomly assigned 8 weeks of either (1) non-exercise (CON); (2) moderate-intensity with high-volume exercise (EX_MHV); or (3) moderate-intensity with low-volume exercise (EX_MLV) (N=6–7, respectively). Femoral BMD and BMC were evaluated using dual energy X-ray absorptiometry, and trabecular and cortical bone were measured using micro-computed tomography. Results Femoral BMD in EX_MHV but not EX_MLV was significantly higher (P<0.05) than in CON. The distal femoral fractional trabecular bone volume/tissue volume (BV/TV, %) was significantly higher (P<0.05) in both EX_MHV and EX_MLV than in CON mice. Increased BV/TV was induced by significantly increased trabecular thickness (mm) and tended to be higher (P<0.10) in BV (mm3) and lower in trabecular separation (mm) in EX_MHV and EX_MLV than in CON. The femoral mid-diaphysis cortical bone was stronger in EX_MLV than EX_MHV. Conclusions Long-term moderate-intensity aerobic exercise with low to high volumes can be thought to have a positive effect on hindlimb BMD and attenuate age-associated trabecular bone loss in the femur. Moderate-intensity aerobic exercise may be an effective and applicable exercise regimen to prevent age-related loss of BMD and BV.
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Affiliation(s)
- Seungyong Lee
- Department of Physiology, College of Graduate Studies, Midwestern University Arizona College of Osteopathic Medicine, Glendale, AZ, USA
| | - Yun-A Shin
- Department of Prescription and Rehabilitation of Exercise, College of Sport Science, Dankook University, Cheonan, Korea
| | - Jinkyung Cho
- Department of Sport Science, Korea Institute of Sport Science, Seoul, Korea
| | - Dong-Ho Park
- Department of Kinesiology, Inha University, Incheon, Korea
- Department of Biomedical Science, Program in Biomedical Science and Engineering, Inha University, Incheon, Korea
| | - Changsun Kim
- Department of Physical Education, Dongduk Women’s University, Seoul, Korea
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Lee S, Shin YA, Cho J, Park DH, Kim C. Trabecular Bone Microarchitecture Improvement Is Associated With Skeletal Nerve Increase Following Aerobic Exercise Training in Middle-Aged Mice. Front Physiol 2022; 12:800301. [PMID: 35273515 PMCID: PMC8902445 DOI: 10.3389/fphys.2021.800301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/21/2021] [Indexed: 01/27/2023] Open
Abstract
Advancing age is associated with bone loss and an increased risk of osteoporosis. Exercise training improves bone metabolism and peripheral nerve regeneration, and may play a critical role in osteogenesis and increase in skeletal nerve fiber density. In this study, the potential positive role of aerobic exercise training in bone metabolism and skeletal nerve regeneration was comprehensively evaluated in 14-month-old male C57BL/6 mice. The mice were divided into two groups: no exercise (non-exercise group) and 8-weeks of aerobic exercise training (exercise group), with six mice in each group. Dual-energy X-ray absorptiometry and micro-computed tomography showed that femoral and tibial bone parameters improved after aerobic exercise training. Greater skeletal nerve fiber density was also observed in the distal femoral and proximal tibial periostea, measured and analyzed by immunofluorescence staining and confocal microscopy. Pearson correlation analysis revealed a significant association between skeletal nerve densities and trabecular bone volume/total volume ratios (distal femur; R 2 = 0.82, p < 0.05, proximal tibia; R 2 = 0.59, p = 0.07) in the exercise group; while in the non-exercise group no significant correlation was found (distal femur; R 2 = 0.10, p = 0.54, proximal tibia; R 2 = 0.12, p = 0.51). Analysis of archival microarray database confirmed that aerobic exercise training changed the microRNA profiles in the mice femora. The differentially expressed microRNAs reinforce the role of aerobic exercise training in the osteogenic and neurogenic potential of femora and tibiae. In conclusion, 8-weeks of aerobic exercise training positively regulate bone metabolism, an effect that paralleled a significant increase in skeletal nerve fiber density. These findings suggest that aerobic exercise training may have dual utility, both as a direct stimulator of bone remodeling and a positive regulator of skeletal nerve regeneration.
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Affiliation(s)
- Seungyong Lee
- Department of Physiology, College of Graduate Studies, Midwestern University, Glendale, AZ, United States
| | - Yun-A Shin
- Department of Exercise Prescription and Rehabilitation, College of Sports Science, Dankook University, Cheonan, South Korea
| | - Jinkyung Cho
- Department of Sport Science, Korea Institute of Sport Science, Seoul, South Korea
| | - Dong-Ho Park
- Department of Kinesiology, Inha University, Incheon, South Korea.,Department of Biomedical Science, Program in Biomedical Science and Engineering, Inha University, Incheon, South Korea
| | - Changsun Kim
- Department of Physical Education, Dongduk Women's University, Seoul, South Korea
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Hsu JJ, Fong F, Patel R, Qiao R, Lo K, Soundia A, Chang CC, Le V, Tseng CH, Demer LL, Tintut Y. Changes in microarchitecture of atherosclerotic calcification assessed by 18F-NaF PET and CT after a progressive exercise regimen in hyperlipidemic mice. J Nucl Cardiol 2021; 28:2207-2214. [PMID: 31897996 PMCID: PMC7329622 DOI: 10.1007/s12350-019-02004-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 12/09/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Despite the association of physical activity with improved cardiovascular outcomes and the association of high coronary artery calcification (CAC) scores with poor prognosis, elite endurance athletes have increased CAC. Yet, they nevertheless have better cardiovascular survival. We hypothesized that exercise may transform vascular calcium deposits to a more stable morphology. METHODS To test this, hyperlipidemic mice (Apoe-/-) with baseline aortic calcification were separated into 2 groups (n = 9/group) with control mice allowed to move ad-lib while the exercise group underwent a progressive treadmill regimen for 9 weeks. All mice underwent blood collections and in vivo 18F-NaF μPET/μCT imaging both at the start and end of the exercise regimen. At euthanasia, aortic root specimens were obtained for histomorphometry. RESULTS Results showed that, while aortic calcification progressed similarly in both groups based on µCT, the fold change in 18F-NaF density was significantly less in the exercise group. Histomorphometric analysis of the aortic root calcium deposits showed that the exercised mice had a lower mineral surface area index than the control group. The exercise regimen also raised serum PTH levels twofold. CONCLUSION These findings suggest that weeks-long progressive exercise alters the microarchitecture of atherosclerotic calcium deposits by reducing mineral surface growth, potentially favoring plaque stability.
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Affiliation(s)
- Jeffrey J Hsu
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Felicia Fong
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Radha Patel
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Rong Qiao
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Karen Lo
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Akrivoula Soundia
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Chih-Chiang Chang
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - Victoria Le
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Chi-Hong Tseng
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Linda L Demer
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yin Tintut
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Orthopaedic Surgery, University of California, Los Angeles, Los Angeles, CA, USA.
- Center for the Health Sciences A2-237, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095-1679, USA.
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Abstract
The skeleton is highly vascularized due to the various roles blood vessels play in the homeostasis of bone and marrow. For example, blood vessels provide nutrients, remove metabolic by-products, deliver systemic hormones, and circulate precursor cells to bone and marrow. In addition to these roles, bone blood vessels participate in a variety of other functions. This article provides an overview of the afferent, exchange and efferent vessels in bone and marrow and presents the morphological layout of these blood vessels regarding blood flow dynamics. In addition, this article discusses how bone blood vessels participate in bone development, maintenance, and repair. Further, mechanical loading-induced bone adaptation is presented regarding interstitial fluid flow and pressure, as regulated by the vascular system. The role of the sympathetic nervous system is discussed in relation to blood vessels and bone. Finally, vascular participation in bone accrual with intermittent parathyroid hormone administration, a medication prescribed to combat age-related bone loss, is described and age- and disease-related impairments in blood vessels are discussed in relation to bone and marrow dysfunction. © 2020 American Physiological Society. Compr Physiol 10:1009-1046, 2020.
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Affiliation(s)
- Rhonda D Prisby
- Bone Vascular and Microcirculation Laboratory, Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, USA
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