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Lee Satcher R, Fiedler B, Ghali A, Dirschl DR. Effect of Spaceflight and Microgravity on the Musculoskeletal System: A Review. J Am Acad Orthop Surg 2024; 32:535-541. [PMID: 38652883 DOI: 10.5435/jaaos-d-23-00954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 03/11/2024] [Indexed: 04/25/2024] Open
Abstract
With National Aeronautics and Space Administration's plans for longer distance, longer duration spaceflights such as missions to Mars and the surge in popularity of space tourism, the need to better understand the effects of spaceflight on the musculoskeletal system has never been more present. However, there is a paucity of information on how spaceflight affects orthopaedic health. This review surveys existing literature and discusses the effect of spaceflight on each aspect of the musculoskeletal system. Spaceflight reduces bone mineral density at rapid rates because of multiple mechanisms. While this seems to be recoverable upon re-exposure to gravity, concern for fracture in spaceflight remains as microgravity impairs bone strength and fracture healing. Muscles, tendons, and entheses similarly undergo microgravity adaptation. These changes result in decreased muscle mass, increased tendon laxity, and decreased enthesis stiffness, thus decreasing the strength of the muscle-tendon-enthesis unit with variable recovery upon gravity re-exposure. Spaceflight also affects joint health; unloading of the joints facilitates changes that thin and atrophy cartilage similar to arthritic phenotypes. These changes are likely recoverable upon return to gravity with exercise. Multiple questions remain regarding effects of longer duration flights on health and implications of these findings on terrestrial medicine, which should be the target of future research.
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Affiliation(s)
- Robert Lee Satcher
- From the Department of Orthopedic Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX (Lee Satcher), and the Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX (Fiedler, Ghali, and Dirschl)
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2
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Barak MM. Cortical and Trabecular Bone Modeling and Implications for Bone Functional Adaptation in the Mammalian Tibia. Bioengineering (Basel) 2024; 11:514. [PMID: 38790379 PMCID: PMC11118124 DOI: 10.3390/bioengineering11050514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/14/2024] [Accepted: 05/17/2024] [Indexed: 05/26/2024] Open
Abstract
Bone modeling involves the addition of bone material through osteoblast-mediated deposition or the removal of bone material via osteoclast-mediated resorption in response to perceived changes in loads by osteocytes. This process is characterized by the independent occurrence of deposition and resorption, which can take place simultaneously at different locations within the bone due to variations in stress levels across its different regions. The principle of bone functional adaptation states that cortical and trabecular bone tissues will respond to mechanical stimuli by adjusting (i.e., bone modeling) their morphology and architecture to mechanically improve their mechanical function in line with the habitual in vivo loading direction. This principle is relevant to various research areas, such as the development of improved orthopedic implants, preventative medicine for osteopenic elderly patients, and the investigation of locomotion behavior in extinct species. In the present review, the mammalian tibia is used as an example to explore cortical and trabecular bone modeling and to examine its implications for the functional adaptation of bones. Following a short introduction and an exposition on characteristics of mechanical stimuli that influence bone modeling, a detailed critical appraisal of the literature on cortical and trabecular bone modeling and bone functional adaptation is given. By synthesizing key findings from studies involving small mammals (rodents), large mammals, and humans, it is shown that examining both cortical and trabecular bone structures is essential for understanding bone functional adaptation. A combined approach can provide a more comprehensive understanding of this significant physiological phenomenon, as each structure contributes uniquely to the phenomenon.
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Affiliation(s)
- Meir M Barak
- Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, Brookville, NY 11548, USA
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3
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Valderrábano RJ, Pencina K, Shang YV, Echevarria E, Dixon R, Ghattas C, Wilson L, Reid KF, Storer T, Garrahan M, Tedtsen T, Zafonte R, Bouxsein M, Bhasin S. Bone microarchitectural alterations associated with spinal cord injury: Relation to sex hormones, metabolic factors, and loading. Bone 2024; 181:117039. [PMID: 38325649 DOI: 10.1016/j.bone.2024.117039] [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: 09/11/2023] [Revised: 01/04/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
CONTEXT People living with spinal cord injury (SCI) are at high risk for bone fractures. Neural, hormonal and metabolic contributors to bone microarchitectural alterations are incompletely understood. OBJECTIVE To determine the relationship of physical, metabolic and endocrine characteristics with bone microarchitecture, characterized using high-resolution peripheral quantitative computed tomography (HRpQCT) in SCI. DESIGN Cross-sectional analyses of bone properties in people with SCI. PARTICIPANTS Twenty adults with SCI and paraplegia (12) or motor incomplete quadriplegia (8). OUTCOME MEASURES Distal tibia and radius HRpQCT parameters, including density, microstructure and strength by microfinite element anaysis (μFEA); sex hormones; metabolic and inflammatory markers. RESULTS The mean age of the participants with SCI was 41.5 ± 10.3 years, BMI 25.7 ± 6.2 kg/m2, time since injury 10.4 ± 9.0 years. Participants with SCI had significantly lower median total (Z score - 3.3), trabecular (-2.93), and cortical vBMD (-1.87), and Failure Load by μFEA (-2.48) at the tibia than controls. However, radius vBMD, aBMD and microarchitecture were similar in participants with SCI and un-injured controls. Unexpectedly, C-Reactive Protein (CRP) was positively associated with tibial trabecular vBMD (β = 0.77, p = 0.02), thickness (β = 0.52, p = 0.04) and number (β = 0.92, p = 0.02). At the radius, estradiol level was positively associated with total vBMD (β = 0.59, p = 0.01), trabecular thickness (β = 0.43, p = 0.04), cortical thickness (β = 0.63, p = 0.01) and cortical porosity (β = 0.74 p = 0.04). CONCLUSIONS Radius vBMD and microarchitecture is preserved but tibial total, cortical and trabecular vBMD, and estimated bone strength are markedly lower and bone microarchitectural parameters substantially degraded in people with SCI. The alterations in bone microarchitecture in people with SCI are likely multifactorial, however marked degradation of bone microarchitecture in tibia but not radius suggests that unloading is an important contributor of site-specific alterations of bone microarchitecture after SCI. Fracture prevention in SCI should focus on strategies to safely increase bone loading. CLINICALTRIALS gov registration #: (NCT03576001).
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Affiliation(s)
- Rodrigo J Valderrábano
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America.
| | - Karol Pencina
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Yili-Valentine Shang
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Evelyn Echevarria
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Robert Dixon
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America; Laboratory of Exercise Physiology and Physical Performance, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Catherine Ghattas
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Lauren Wilson
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Kieran F Reid
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America; Laboratory of Exercise Physiology and Physical Performance, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Thomas Storer
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Margaret Garrahan
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, United States of America
| | - Trinity Tedtsen
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, United States of America
| | - Ross Zafonte
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Massachusetts General Hospital, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - Mary Bouxsein
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, United States of America; Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States of America
| | - Shalender Bhasin
- Research Program in Men's Health, Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center for Function Promoting Therapies, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States of America
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4
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Hughes L, Centner C. Idiosyncratic bone responses to blood flow restriction exercise: new insights and future directions. J Appl Physiol (1985) 2024; 136:283-297. [PMID: 37994414 PMCID: PMC11212818 DOI: 10.1152/japplphysiol.00723.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 11/14/2023] [Accepted: 11/21/2023] [Indexed: 11/24/2023] Open
Abstract
Applying blood flow restriction (BFR) during low-load exercise induces beneficial adaptations of the myotendinous and neuromuscular systems. Despite the low mechanical tension, BFR exercise facilitates a localized hypoxic environment and increase in metabolic stress, widely regarded as the primary stimulus for tissue adaptations. First evidence indicates that low-load BFR exercise is effective in promoting an osteogenic response in bone, although this has previously been postulated to adapt primarily during high-impact weight-bearing exercise. Besides studies investigating the acute response of bone biomarkers following BFR exercise, first long-term trials demonstrate beneficial adaptations in bone in both healthy and clinical populations. Despite the increasing number of studies, the physiological mechanisms are largely unknown. Moreover, heterogeneity in methodological approaches such as biomarkers of bone metabolism measured, participant and study characteristics, and time course of measurement renders it difficult to formulate accurate conclusions. Furthermore, incongruity in the methods of BFR application (e.g., cuff pressure) limits the comparability of datasets and thus hinders generalizability of study findings. Appropriate use of biomarkers, effective BFR application, and befitting study design have the potential to progress knowledge on the acute and chronic response of bone to BFR exercise and contribute toward the development of a novel strategy to protect or enhance bone health. Therefore, the purpose of the present synthesis review is to 1) evaluate current mechanistic evidence; 2) discuss and offer explanations for similar and contrasting data findings; and 3) create a methodological framework for future mechanistic and applied research.
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Affiliation(s)
- Luke Hughes
- Department of Sport Exercise & Rehabilitation, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Christoph Centner
- Department of Sport and Sport Science, University of Freiburg, Freiburg, Germany
- Praxisklinik Rennbahn, Muttenz, Switzerland
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Issertine M, Rosa‐Calwell ME, Sung D, Bouxsein ML, Rutkove SB, Mortreux M. Adaptation to full weight-bearing following disuse in rats: The impact of biological sex on musculoskeletal recovery. Physiol Rep 2024; 12:e15938. [PMID: 38383049 PMCID: PMC10881285 DOI: 10.14814/phy2.15938] [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: 12/21/2023] [Revised: 01/01/2024] [Accepted: 01/01/2024] [Indexed: 02/23/2024] Open
Abstract
With the technological advances made to expand space exploration, astronauts will spend extended amounts of time in space before returning to Earth. This situation of unloading and reloading influences human physiology, and readaptation to full weight-bearing may significantly impact astronauts' health. On Earth, similar situations can be observed in patients who are bedridden or suffer from sport-related injuries. However, our knowledge of male physiology far exceeds our knowledge of female's, which creates an important gap that needs to be addressed to understand the sex-based differences regarding musculoskeletal adaptation to unloading and reloading, necessary to preserve health of both sexes. Using a ground-based model of total unloading for 14 days and reloading at full weight-bearing for 7 days rats, we aimed to compare the musculoskeletal adaptations between males and females. Our results reveal the existence of significant differences. Indeed, males experienced bone loss both during the unloading and the reloading period while females did not. During simulated microgravity, males and females showed comparable muscle deconditioning with a significant decline in rear paw grip strength. However, after 7 days of recovery, muscle strength improved. Additionally, sex-based differences in myofiber size existing at baseline are significantly reduced or eliminated following unloading and recovery.
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Affiliation(s)
- Margot Issertine
- Department of NeurologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
| | - Megan E. Rosa‐Calwell
- Department of NeurologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
| | - Dong‐Min Sung
- Department of NeurologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
| | - Mary L. Bouxsein
- Harvard Medical SchoolBostonMassachusettsUSA
- Department of Orthopedic SurgeryBeth Israel Deaconess Medical Center, Center for Advanced Orthopaedic StudiesBostonMassachusettsUSA
| | - Seward B. Rutkove
- Department of NeurologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
| | - Marie Mortreux
- Department of NeurologyBeth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Harvard Medical SchoolBostonMassachusettsUSA
- Department of NutritionUniversity of Rhode IslandKingstonRhode IslandUSA
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Kemp TD, Besler BA, Gabel L, Boyd SK. Predicting Bone Adaptation in Astronauts during and after Spaceflight. Life (Basel) 2023; 13:2183. [PMID: 38004323 PMCID: PMC10672697 DOI: 10.3390/life13112183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 10/27/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
A method was previously developed to identify participant-specific parameters in a model of trabecular bone adaptation from longitudinal computed tomography (CT) imaging. In this study, we use these numerical methods to estimate changes in astronaut bone health during the distinct phases of spaceflight and recovery on Earth. Astronauts (N = 16) received high-resolution peripheral quantitative CT (HR-pQCT) scans of their distal tibia prior to launch (L), upon their return from an approximately six-month stay on the international space station (R+0), and after six (R+6) and 12 (R+12) months of recovery. To model trabecular bone adaptation, we determined participant-specific parameters at each time interval and estimated their bone structure at R+0, R+6, and R+12. To assess the fit of our model to this population, we compared static and dynamic bone morphometry as well as the Dice coefficient and symmetric distance at each measurement. In general, modeled and observed static morphometry were highly correlated (R2> 0.94) and statistically different (p < 0.0001) but with errors close to HR-pQCT precision limits. Dynamic morphometry, which captures rates of bone adaptation, was poorly estimated by our model (p < 0.0001). The Dice coefficient and symmetric distance indicated a reasonable local fit between observed and predicted bone volumes. This work applies a general and versatile computational framework to test bone adaptation models. Future work can explore and test increasingly sophisticated models (e.g., those including load or physiological factors) on a participant-specific basis.
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Affiliation(s)
- Tannis D. Kemp
- Department of Mechanical and Manufacturing Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Bryce A. Besler
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Leigh Gabel
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Steven K. Boyd
- Department of Mechanical and Manufacturing Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
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Hughes JM, Greeves JP. Editorial on: Association between Combat-Related Traumatic Injury and Skeletal Health: Bone Mineral Density Loss Is Localized and Correlates with Altered Loading in Amputees: The ADVANCE Study. J Bone Miner Res 2023; 38:1223-1224. [PMID: 37607690 DOI: 10.1002/jbmr.4891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 07/25/2023] [Accepted: 08/01/2023] [Indexed: 08/24/2023]
Affiliation(s)
- Julie M Hughes
- Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, UK
- Division of Surgery and Interventional Science, University College London, London, UK
- Norwich Medical School, University of East Anglia, Norwich, UK
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8
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Liu T, Melkus G, Ramsay T, Sheikh A, Laneuville O, Trudel G. Bone marrow adiposity modulation after long duration spaceflight in astronauts. Nat Commun 2023; 14:4799. [PMID: 37558686 PMCID: PMC10412640 DOI: 10.1038/s41467-023-40572-8] [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: 04/03/2023] [Accepted: 07/31/2023] [Indexed: 08/11/2023] Open
Abstract
Space travel requires metabolic adaptations from multiple systems. While vital to bone and blood production, human bone marrow adipose (BMA) tissue modulation in space is unknown. Here we show significant downregulation of the lumbar vertebrae BMA in 14 astronauts, 41 days after landing from six months' missions on the International Space Station. Spectral analyses indicated depletion of marrow adipose reserves. We then demonstrate enhanced erythropoiesis temporally related to low BMA. Next, we demonstrated systemic and then, local lumbar vertebrae bone anabolism temporally related to low BMA. These support the hypothesis that BMA is a preferential local energy source supplying the hypermetabolic bone marrow postflight, leading to its downregulation. A late postflight upregulation abolished the lower BMA of female astronauts and BMA modulation amplitude was higher in younger astronauts. The study design in the extreme environment of space can limit these conclusions. BMA modulation in astronauts can help explain observations on Earth.
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Affiliation(s)
- Tammy Liu
- Bone and Joint Research Laboratory, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8M2, Canada
| | - Gerd Melkus
- Department of Radiology, Radiation Oncology and Medical Physics, University of Ottawa, Ottawa, ON, K1H 8M2, Canada
| | - Tim Ramsay
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, K1H 8M2, Canada
| | - Adnan Sheikh
- Department of Radiology, Radiation Oncology and Medical Physics, University of Ottawa, Ottawa, ON, K1H 8M2, Canada
| | - Odette Laneuville
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| | - Guy Trudel
- Bone and Joint Research Laboratory, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8M2, Canada.
- Department of Medicine, Division of Physical Medicine and Rehabilitation, The Ottawa Hospital, Ottawa, ON, K1H 8M2, Canada.
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M2, Canada.
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9
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Rahman MM, Watton PN, Neu CP, Pierce DM. A chemo-mechano-biological modeling framework for cartilage evolving in health, disease, injury, and treatment. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 231:107419. [PMID: 36842346 DOI: 10.1016/j.cmpb.2023.107419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND AND OBJECTIVE Osteoarthritis (OA) is a pervasive and debilitating disease, wherein degeneration of cartilage features prominently. Despite extensive research, we do not yet understand the cause or progression of OA. Studies show biochemical, mechanical, and biological factors affect cartilage health. Mechanical loads influence synthesis of biochemical constituents which build and/or break down cartilage, and which in turn affect mechanical loads. OA-associated biochemical profiles activate cellular activity that disrupts homeostasis. To understand the complex interplay among mechanical stimuli, biochemical signaling, and cartilage function requires integrating vast research on experimental mechanics and mechanobiology-a task approachable only with computational models. At present, mechanical models of cartilage generally lack chemo-biological effects, and biochemical models lack coupled mechanics, let alone interactions over time. METHODS We establish a first-of-its kind virtual cartilage: a modeling framework that considers time-dependent, chemo-mechano-biologically induced turnover of key constituents resulting from biochemical, mechanical, and/or biological activity. We include the "minimally essential" yet complex chemical and mechanobiological mechanisms. Our 3-D framework integrates a constitutive model for the mechanics of cartilage with a novel model of homeostatic adaptation by chondrocytes to pathological mechanical stimuli, and a new application of anisotropic growth (loss) to simulate degradation clinically observed as cartilage thinning. RESULTS Using a single set of representative parameters, our simulations of immobilizing and overloading successfully captured loss of cartilage quantified experimentally. Simulations of immobilizing, overloading, and injuring cartilage predicted dose-dependent recovery of cartilage when treated with suramin, a proposed therapeutic for OA. The modeling framework prompted us to add growth factors to the suramin treatment, which predicted even better recovery. CONCLUSIONS Our flexible framework is a first step toward computational investigations of how cartilage and chondrocytes mechanically and biochemically evolve in degeneration of OA and respond to pharmacological therapies. Our framework will enable future studies to link physical activity and resulting mechanical stimuli to progression of OA and loss of cartilage function, facilitating new fundamental understanding of the complex progression of OA and elucidating new perspectives on causes, treatments, and possible preventions.
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Affiliation(s)
| | - Paul N Watton
- Department of Computer Science & Insigneo Institute for in silico Medicine, University of Sheffield, Sheffield, UK; Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA, USA
| | - Corey P Neu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA
| | - David M Pierce
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT, USA; Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA.
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Buettmann EG, DeNapoli RC, Abraham LB, Denisco JA, Lorenz MR, Friedman MA, Donahue HJ. Reambulation following hindlimb unloading attenuates disuse-induced changes in murine fracture healing. Bone 2023; 172:116748. [PMID: 37001629 DOI: 10.1016/j.bone.2023.116748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 03/31/2023]
Abstract
Patients with bone and muscle loss from prolonged disuse have higher risk of falls and subsequent fragility fractures. In addition, fracture patients with continued disuse and/or delayed physical rehabilitation have worse clinical outcomes compared to individuals with immediate weight-bearing activity following diaphyseal fracture. However, the effects of prior disuse followed by physical reambulation on fracture healing cellular processes and adjacent bone and skeletal muscle recovery post-injury remains poorly defined. To bridge this knowledge gap and inform future treatment and rehabilitation strategies for fractures, a preclinical model of fracture healing with a history of prior unloading with and without reambulation was employed. First, skeletally mature male and female C57BL/6J mice (18 weeks) underwent hindlimb unloading by tail suspension (HLU) for 3 weeks to induce significant bone and muscle loss modeling enhanced bone fragility. Next, mice had their right femur fractured by open surgical dissection (stabilized with 24-gauge pin). The, mice were randomly assigned to continued HLU or allowed normal weight-bearing reambulation (HLU + R). Mice given normal cage activity throughout the experiment served as healthy age-matched controls. All mice were sacrificed 4-days (DPF4) or 14-days (DPF14) following fracture to assess healing and uninjured hindlimb musculoskeletal properties (6-10 mice per treatment/biological sex). We found that continued disuse following fracture lead to severely diminished uninjured hindlimb skeletal muscle mass (gastrocnemius and soleus) and femoral bone volume adjacent to the fracture site compared to healthy age-matched controls across mouse sexes. Furthermore, HLU led to significantly decreased periosteal expansion (DPF4) and osteochondral tissue formation by DPF14, and trends in increased osteoclastogenesis (DPF14) and decreased woven bone vascular area (DPF14). In contrast, immediate reambulation for 2 weeks after fracture, even following a period of prolonged disuse, was able to increase hindlimb skeletal tissue mass and increase osteochondral tissue formation, albeit not to healthy control levels, in both mouse sexes. Furthermore, reambulation attenuated osteoclast formation seen in woven bone tissue undergoing disuse. Our results suggest that weight-bearing skeletal loading in both sexes immediately following fracture may improve callus healing and prevent further fall risk by stimulating skeletal muscle anabolism and decreasing callus resorption compared to minimal or delayed rehabilitation regimens.
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Affiliation(s)
- Evan G Buettmann
- Virginia Commonwealth University, Biomedical Engineering, Richmond, VA, United States of America
| | - Rachel C DeNapoli
- Virginia Commonwealth University, Biomedical Engineering, Richmond, VA, United States of America
| | - Lovell B Abraham
- Virginia Commonwealth University, Biomedical Engineering, Richmond, VA, United States of America
| | - Joe A Denisco
- Virginia Commonwealth University, Biomedical Engineering, Richmond, VA, United States of America
| | - Madelyn R Lorenz
- Virginia Commonwealth University, Biomedical Engineering, Richmond, VA, United States of America
| | - Michael A Friedman
- Virginia Commonwealth University, Biomedical Engineering, Richmond, VA, United States of America
| | - Henry J Donahue
- Virginia Commonwealth University, Biomedical Engineering, Richmond, VA, United States of America.
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11
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Liu CJ, Yang X, Wang SH, Wu XT, Mao Y, Shi JW, Fan YB, Sun LW. Preventing Disused Bone Loss through Inhibition of Advanced Glycation End Products. Int J Mol Sci 2023; 24:ijms24054953. [PMID: 36902384 PMCID: PMC10003672 DOI: 10.3390/ijms24054953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/26/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
Bone loss occurs in astronauts during long-term space flight, but the mechanisms are still unclear. We previously showed that advanced glycation end products (AGEs) were involved in microgravity-induced osteoporosis. Here, we investigated the improvement effects of blocking AGEs formation on microgravity-induced bone loss by using the AGEs formation inhibitor, irbesartan. To achieve this objective, we used a tail-suspended (TS) rat model to simulate microgravity and treated the TS rats with 50 mg/kg/day irbesartan, as well as the fluorochrome biomarkers injected into rats to label dynamic bone formation. To assess the accumulation of AGEs, pentosidine (PEN), non-enzymatic cross-links (NE-xLR), and fluorescent AGEs (fAGEs) were identified in the bone; 8-hydroxydeoxyguanosine (8-OHdG) was analyzed for the reactive oxygen species (ROS) level in the bone. Meanwhile, bone mechanical properties, bone microstructure, and dynamic bone histomorphometry were tested for bone quality assessment, and Osterix and TRAP were immunofluorescences stained for the activities of osteoblastic and osteoclastic cells. Results showed AGEs increased significantly and 8-OHdG expression in bone showed an upward trend in TS rat hindlimbs. The bone quality (bone microstructure and mechanical properties) and bone formation process (dynamic bone formation and osteoblastic cells activities) were inhibited after tail-suspension, and showed a correlation with AGEs, suggesting the elevated AGEs contributed to the disused bone loss. After being treated with irbesartan, the increased AGEs and 8-OHdG expression were significantly inhibited, suggesting irbesartan may reduce ROS to inhibit dicarbonyl compounds, thus suppressing AGEs production after tail-suspension. The inhibition of AGEs can partially alter the bone remodeling process and improve bone quality. Both AGEs accumulation and bone alterations almost occurred in trabecular bone but not in cortical bone, suggesting AGEs effects on bone remodeling under microgravity are dependent on the biological milieu.
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Affiliation(s)
| | - Xiao Yang
- Correspondence: (X.Y.); (L.-W.S.); Tel.: +86-13811922096 (X.Y.); Fax: +86-10-82339349 (L.-W.S.)
| | | | | | | | | | | | - Lian-Wen Sun
- Correspondence: (X.Y.); (L.-W.S.); Tel.: +86-13811922096 (X.Y.); Fax: +86-10-82339349 (L.-W.S.)
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Chaloulakou S, Poulia KA, Karayiannis D. Physiological Alterations in Relation to Space Flight: The Role of Nutrition. Nutrients 2022; 14:nu14224896. [PMID: 36432580 PMCID: PMC9699067 DOI: 10.3390/nu14224896] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 11/22/2022] Open
Abstract
Astronauts exhibit several pathophysiological changes due to a variety of stressors related to the space environment, including microgravity, space radiation, isolation, and confinement. Space motion sickness, bone and muscle mass loss, cardiovascular deconditioning and neuro-ocular syndrome are some of the spaceflight-induced effects on human health. Optimal nutrition is of the utmost importance, and-in combination with other measures, such as physical activity and pharmacological treatment-has a key role in mitigating many of the above conditions, including bone and muscle mass loss. Since the beginning of human space exploration, space food has not fully covered astronauts' needs. They often suffer from menu fatigue and present unintentional weight loss, which leads to further alterations. The purpose of this review was to explore the role of nutrition in relation to the pathophysiological effects of spaceflight on the human body.
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Affiliation(s)
- Stavroula Chaloulakou
- Department of Clinical Nutrition, “Evangelismos” General Hospital of Athens, 10676 Athens, Greece
| | - Kalliopi Anna Poulia
- Laboratory of Dietetics and Quality of Life, Department of Food Science & Human Nutrition, School of Food and Nutritional Sciences, Agricultural University of Athens, 11855 Athens, Greece
| | - Dimitrios Karayiannis
- Department of Clinical Nutrition, “Evangelismos” General Hospital of Athens, 10676 Athens, Greece
- Correspondence: ; Tel.: +30-213-2045035
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