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Wakefield B, Tang J, Hutchinson JL, Kanji R, Brooks C, Grol MW, Séguin CA, Penuela S, Beier F. Pannexin 3 deletion in mice results in knee osteoarthritis and intervertebral disc degeneration after forced treadmill running. J Orthop Res 2024; 42:1696-1709. [PMID: 38499500 DOI: 10.1002/jor.25830] [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: 05/04/2023] [Revised: 11/10/2023] [Accepted: 02/26/2024] [Indexed: 03/20/2024]
Abstract
Pannexin 3 (Panx3) is a glycoprotein that forms mechanosensitive channels expressed in chondrocytes and annulus fibrosus cells of the intervertebral disc (IVD). Evidence suggests Panx3 plays contrasting roles in traumatic versus aging osteoarthritis (OA) and intervertebral disc degeneration (IDD). However, whether its deletion influences the response of joint tissue to forced use is unknown. The purpose of this study was to determine if Panx3 deletion in mice causes increased knee joint OA and IDD after forced treadmill running. Male and female wildtype (WT) and Panx3 knockout (KO) mice were randomized to either a no-exercise group (sedentary; SED) or daily forced treadmill running (forced exercise; FEX) from 24 to 30 weeks of age. Knee cartilage and IVD histopathology were evaluated by histology, while tibial secondary ossification centers were analyzed using microcomputed tomography (µCT). Both male and female Panx3 KO mice developed larger superficial defects of the tibial cartilage after forced treadmill running compared with SED WT mice. Additionally, Panx3 KO mice developed reduced bone volume, and female PANX3 KO mice had lengthening of the lateral tubercle at the intercondylar eminence. In the lower lumbar spine, both male and female Panx3 KO mice developed histopathological features of IDD after running compared to SED WT mice. These findings suggest that the combination of deleting Panx3 and forced treadmill running induces OA and causes histopathological changes associated with the degeneration of the IVDs in mice.
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Affiliation(s)
- Brent Wakefield
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
| | - Justin Tang
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
| | - Jeffrey L Hutchinson
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Rehanna Kanji
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Courtney Brooks
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Matthew W Grol
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Cheryle A Séguin
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
| | - Frank Beier
- Western's Bone and Joint Institute, The Dr. Sandy Kirkley Centre for Musculoskeletal Research, University Hospital, London, Ontario, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
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Beaver LM, Prati M, Gilman KE, Luo T, Shay NF, Branscum AJ, Turner RT, Iwaniec UT. Diet composition influences the effect of high fat diets on bone in growing male mice. Bone 2023; 176:116888. [PMID: 37652285 DOI: 10.1016/j.bone.2023.116888] [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: 04/28/2023] [Revised: 08/26/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
The effect of diet-induced obesity on bone in rodents is variable, with bone mass increases, decreases, and no impact reported. The goal of this study was to evaluate whether the composition of obesogenic diet may influence bone independent of its effect on body weight. As proof-of-principle, we used a mouse model to compare the skeletal effects of a commonly used high fat 'Western' diet and a modified high fat diet. The modified high fat diet included ground English walnut and was isocaloric for macronutrients, but differed in fatty acid composition and contained nutrients (e.g. polyphenols) not present in the standard 'Western' diet. Eight-week-old mice were randomized into 1 of 3 dietary treatments (n = 8/group): (1) low fat control diet (LF; 10 % kcal fat); (2) high fat 'Western' diet (HF; 46 % kcal fat as soybean oil and lard); or (3) modified high fat diet supplemented with ground walnuts (HF + walnut; 46 % kcal fat as soybean oil, lard, and walnut) and maintained on their respective diets for 9 weeks. Bone response in femur was then evaluated using dual energy x-ray absorptiometry, microcomputed tomography, and histomorphometry. Consumption of both obesogenic diets resulted in increased weight gain but differed in impact on bone and bone marrow adiposity in distal femur metaphysis. Mice consuming the high fat 'Western' diet exhibited a tendency for lower cancellous bone volume fraction and connectivity density, and had lower osteoblast-lined bone perimeter (an index of bone formation) and higher bone marrow adiposity than low fat controls. Mice fed the modified high fat diet did not differ from mice fed control (low fat) diet in cancellous bone microarchitecture, or osteoblast-lined bone perimeter, and exhibited lower bone marrow adiposity compared to mice fed the 'Western' diet. This proof-of-principal study demonstrates that two obesogenic diets, similar in macronutrient distribution and induction of weight gain, can have different effects on cancellous bone in distal femur metaphysis. Because the composition of the diets used to induce obesity in rodents does not recapitulate a common human diet, our finding challenges the translatability of rodent studies evaluating the impact of diet-induced obesity on bone.
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Affiliation(s)
- Laura M Beaver
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA; Linus Pauling Institute, Oregon State University, Corvallis, OR, USA
| | - Maud Prati
- Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Kristy E Gilman
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
| | - Ting Luo
- Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Neil F Shay
- Food Science and Technology, Oregon State University, Corvallis, OR, USA
| | - Adam J Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA
| | - Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR, USA
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR, USA.
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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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Bensreti H, Yu K, Alhamad DW, Shaver J, Kaiser H, Zhong R, Whichard WC, Parker E, Grater L, Faith H, Johnson M, Cooley MA, Fulzele S, Hill WD, Isales CM, Hamrick MW, McGee-Lawrence ME. Orchiectomy sensitizes cortical bone in male mice to the harmful effects of kynurenine. Bone 2023:116811. [PMID: 37244427 DOI: 10.1016/j.bone.2023.116811] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 05/29/2023]
Abstract
Kynurenine (Kyn) is a tryptophan metabolite that increases with age and promotes musculoskeletal dysfunction. We previously found a sexually dimorphic pattern in how Kyn affects bone, with harmful effects more prevalent in females than males. This raises the possibility that male sex steroids might exert a protective effect that blunts the effects of Kyn in males. To test this, orchiectomy (ORX) or sham surgeries were performed on 6-month-old C57BL/6 mice, after which mice received Kyn (10 mg/kg) or vehicle via intraperitoneal injection, once daily, 5×/week, for four weeks. Bone histomorphometry, DXA, microCT, and serum marker analyses were performed after sacrifice. In vitro studies were performed to specifically test the effect of testosterone on activation of aryl hydrocarbon receptor (AhR)-mediated signaling by Kyn in mesenchymal-lineage cells. Kyn treatment reduced cortical bone mass in ORX- but not sham-operated mice. Trabecular bone was unaffected. Kyn's effects on cortical bone in ORX mice were attributed primarily to enhanced endosteal bone resorption activity. Bone marrow adipose tissue was increased in Kyn-treated ORX animals but was unchanged by Kyn in sham-operated mice. ORX surgery increased mRNA expression of the aryl hydrocarbon receptor (AhR) and its target gene Cyp1a1 in the bone, suggesting a priming and/or amplification of AhR signaling pathways. Mechanistic in vitro studies revealed that testosterone blunted Kyn-stimulated AhR transcriptional activity and Cyp1a1 expression in mesenchymal-linage cells. These data suggest a protective role for male sex steroids in blunting the harmful effects of Kyn in cortical bone. Therefore, testosterone may play an important role in regulating Kyn/AhR signaling in musculoskeletal tissues, suggesting crosstalk between male sex steroids and Kyn signaling may influence age-associated musculoskeletal frailty.
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Affiliation(s)
- Husam Bensreti
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Kanglun Yu
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Dima W Alhamad
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Joseph Shaver
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Helen Kaiser
- Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, SC, United States of America
| | - Roger Zhong
- Department of Neuroscience & Regenerative Medicine, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - William C Whichard
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Emily Parker
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Lindsey Grater
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Hayden Faith
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Maribeth Johnson
- Department of Neuroscience & Regenerative Medicine, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Marion A Cooley
- Department of Oral Biology & Diagnostic Sciences, Dental Collage of Georgia at Augusta University, Augusta, GA, United States of America
| | - Sadanand Fulzele
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - William D Hill
- Department of Pathology, Medical University of South Carolina, Charleston, SC, United States of America
| | - Carlos M Isales
- Department of Neuroscience & Regenerative Medicine, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Mark W Hamrick
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America
| | - Meghan E McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of, Georgia at Augusta University, Augusta, GA, United States of America.
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Changes in interstitial fluid flow, mass transport and the bone cell response in microgravity and normogravity. Bone Res 2022; 10:65. [PMID: 36411278 PMCID: PMC9678891 DOI: 10.1038/s41413-022-00234-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 08/17/2022] [Accepted: 08/29/2022] [Indexed: 11/22/2022] Open
Abstract
In recent years, our scientific interest in spaceflight has grown exponentially and resulted in a thriving area of research, with hundreds of astronauts spending months of their time in space. A recent shift toward pursuing territories farther afield, aiming at near-Earth asteroids, the Moon, and Mars combined with the anticipated availability of commercial flights to space in the near future, warrants continued understanding of the human physiological processes and response mechanisms when in this extreme environment. Acute skeletal loss, more severe than any bone loss seen on Earth, has significant implications for deep space exploration, and it remains elusive as to why there is such a magnitude of difference between bone loss on Earth and loss in microgravity. The removal of gravity eliminates a critical primary mechano-stimulus, and when combined with exposure to both galactic and solar cosmic radiation, healthy human tissue function can be negatively affected. An additional effect found in microgravity, and one with limited insight, involves changes in dynamic fluid flow. Fluids provide the most fundamental way to transport chemical and biochemical elements within our bodies and apply an essential mechano-stimulus to cells. Furthermore, the cell cytoplasm is not a simple liquid, and fluid transport phenomena together with viscoelastic deformation of the cytoskeleton play key roles in cell function. In microgravity, flow behavior changes drastically, and the impact on cells within the porous system of bone and the influence of an expanding level of adiposity are not well understood. This review explores the role of interstitial fluid motion and solute transport in porous bone under two different conditions: normogravity and microgravity.
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Reynolds RJ, Scott RT, Turner RT, Iwaniec UT, Bouxsein ML, Sanders LM, Antonsen EL. Validating Causal Diagrams of Human Health Risks for Spaceflight: An Example Using Bone Data from Rodents. Biomedicines 2022; 10:2187. [PMID: 36140288 PMCID: PMC9496259 DOI: 10.3390/biomedicines10092187] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/12/2022] [Accepted: 08/12/2022] [Indexed: 12/24/2022] Open
Abstract
As part of the risk management plan for human system risks at the US National Aeronautics and Space Administration (NASA), the NASA Human Systems Risk Board uses causal diagrams (in the form of directed, acyclic graphs, or DAGs) to communicate the complex web of events that leads from exposure to the spaceflight environment to performance and health outcomes. However, the use of DAGs in this way is relatively new at NASA, and thus far, no method has been articulated for testing their veracity using empirical data. In this paper, we demonstrate a set of procedures for doing so, using (a) a DAG related to the risk of bone fracture after exposure to spaceflight; and (b) four datasets originally generated to investigate this phenomenon in rodents. Tests of expected marginal correlation and conditional independencies derived from the DAG indicate that the rodent data largely agree with the structure of the diagram. Incongruencies between tests and the expected relationships in one of the datasets are likely explained by inadequate representation of a key DAG variable in the dataset. Future directions include greater tie-in with human data sources, including multiomics data, which may allow for more robust characterization and measurement of DAG variables.
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Affiliation(s)
- Robert J. Reynolds
- KBR Wyle Services, LLC, NASA Johnson Space Center, Houston, TX 77058, USA
| | - Ryan T. Scott
- KBR, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA 94043, USA
| | - Russell T. Turner
- Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA
| | - Urszula T. Iwaniec
- Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA
| | - Mary L. Bouxsein
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
- Department of Orthopedic Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Lauren M. Sanders
- Blue Marble Space Institute of Science, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA 94043, USA
| | - Erik L. Antonsen
- Department of Emergency Medicine, Center for Space Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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Turner RT, Nesser KL, Philbrick KA, Wong CP, Olson DA, Branscum AJ, Iwaniec UT. Leptin and environmental temperature as determinants of bone marrow adiposity in female mice. Front Endocrinol (Lausanne) 2022; 13:959743. [PMID: 36277726 PMCID: PMC9582271 DOI: 10.3389/fendo.2022.959743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/15/2022] [Indexed: 11/21/2022] Open
Abstract
Bone marrow adipose tissue (BMAT) levels are higher in distal femur metaphysis of female mice housed at thermoneutral (32°C) than in mice housed at 22°C, as are abdominal white adipose tissue (WAT) mass, and serum leptin levels. We performed two experiments to explore the role of increased leptin in temperature-enhanced accrual of BMAT. First, we supplemented 6-week-old female C57BL/6J (B6) mice with leptin for 2 weeks at 10 µg/d using a subcutaneously implanted osmotic pump. Controls consisted of ad libitum (ad lib) fed mice and mice pair fed to match food intake of leptin-supplemented mice. The mice were maintained at 32°C for the duration of treatment. At necropsy, serum leptin in leptin-supplemented mice did not differ from ad lib mice, suggesting suppression of endogenous leptin production. In support, Ucp1 expression in BAT, percent body fat, and abdominal WAT mass were lower in leptin-supplemented mice. Leptin-supplemented mice also had lower BMAT and higher bone formation in distal femur metaphysis compared to the ad lib group, changes not replicated by pair-feeding. In the second experiment, BMAT response was evaluated in 6-week-old female B6 wild type (WT), leptin-deficient ob/ob and leptin-treated (0.3 μg/d) ob/ob mice housed at 32°C for the 2-week duration of the treatment. Compared to mice sacrificed at baseline (22°C), BMAT increased in ob/ob mice as well as WT mice, indicating a leptin independent response to increased temperature. However, infusion of ob/ob mice with leptin, at a dose rate having negligible effects on either energy metabolism or serum leptin levels, attenuated the increase in BMAT. In summary, increased housing temperature and increased leptin have independent but opposing effects on BMAT in mice.
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Affiliation(s)
- Russell T. Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States
- Center for Healthy Aging Research, Oregon State University, Corvallis, OR, United States
| | - Kira L. Nesser
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States
| | - Kenneth A. Philbrick
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States
| | - Carmen P. Wong
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States
| | - Dawn A. Olson
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States
| | - Adam J. Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States
| | - Urszula T. Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States
- Center for Healthy Aging Research, Oregon State University, Corvallis, OR, United States
- *Correspondence: Urszula T. Iwaniec,
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Mitchell DR, Wroe S, Ravosa MJ, Menegaz RA. More Challenging Diets Sustain Feeding Performance: Applications Toward the Captive Rearing of Wildlife. Integr Org Biol 2021; 3:obab030. [PMID: 34888486 PMCID: PMC8653637 DOI: 10.1093/iob/obab030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/09/2021] [Accepted: 10/20/2021] [Indexed: 11/14/2022] Open
Abstract
The rescue and rehabilitation of young fauna is of substantial importance to conservation. However, it has been suggested that incongruous diets offered in captive environments may alter craniofacial morphology and hinder the success of reintroduced animals. Despite these claims, to what extent dietary variation throughout ontogeny impacts intrapopulation cranial biomechanics has not yet been tested. Here, finite element models were generated from the adult crania of 40 rats (n = 10 per group) that were reared on 4 different diet regimes and stress magnitudes compared during incisor bite simulations. The diets consisted of (1) exclusively hard pellets from weaning, (2) exclusively soft ground pellet meal from weaning, (3) a juvenile switch from pellets to meal, and (4) a juvenile switch from meal to pellets. We hypothesized that a diet of exclusively soft meal would result in the weakest adult skulls, represented by significantly greater stress magnitudes at the muzzle, palate, and zygomatic arch. Our hypothesis was supported at the muzzle and palate, indicating that a diet limited to soft food inhibits bone deposition throughout ontogeny. This finding presents a strong case for a more variable and challenging diet during development. However, rather than the "soft" diet group resulting in the weakest zygomatic arch as predicted, this region instead showed the highest stress among rats that switched as juveniles from hard pellets to soft meal. We attribute this to a potential reduction in number and activity of osteoblasts, as demonstrated in studies of sudden and prolonged disuse of bone. A shift to softer foods in captivity, during rehabilitation after injury in the wild for example, can therefore be detrimental to healthy development of the skull in some growing animals, potentially increasing the risk of injury and impacting the ability to access full ranges of wild foods upon release. We suggest captive diet plans consider not just nutritional requirements but also food mechanical properties when rearing wildlife to adulthood for reintroduction.
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Affiliation(s)
- D Rex Mitchell
- Center for Anatomical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Stephen Wroe
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Matthew J Ravosa
- Departments of Biological Sciences, Aerospace and Mechanical Engineering, and Anthropology, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Rachel A Menegaz
- Center for Anatomical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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Fu J, Goldsmith M, Crooks SD, Condon SF, Morris M, Komarova SV. Bone health in spacefaring rodents and primates: systematic review and meta-analysis. NPJ Microgravity 2021; 7:19. [PMID: 34075059 PMCID: PMC8169759 DOI: 10.1038/s41526-021-00147-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 04/28/2021] [Indexed: 11/09/2022] Open
Abstract
Animals in space exploration studies serve both as a model for human physiology and as a means to understand the physiological effects of microgravity. To quantify the microgravity-induced changes to bone health in animals, we systematically searched Medline, Embase, Web of Science, BIOSIS, and NASA Technical reports. We selected 40 papers focusing on the bone health of 95 rats, 61 mice, and 9 rhesus monkeys from 22 space missions. The percentage difference from ground control in rodents was -24.1% [Confidence interval: -43.4, -4.9] for trabecular bone volume fraction and -5.9% [-8.0, -3.8] for the cortical area. In primates, trabecular bone volume fraction was lower by -25.2% [-35.6, -14.7] in spaceflight animals compared to GC. Bone formation indices in rodent trabecular and cortical bone were significantly lower in microgravity. In contrast, osteoclast numbers were not affected in rats and were variably affected in mice. Thus, microgravity induces bone deficits in rodents and primates likely through the suppression of bone formation.
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Affiliation(s)
- Jingyan Fu
- Shriners Hospitals for Children - Canada, Montréal, Canada
| | - Matthew Goldsmith
- Shriners Hospitals for Children - Canada, Montréal, Canada
- Faculty of Dentistry, McGill University, Montréal, Canada
| | | | - Sean F Condon
- Shriners Hospitals for Children - Canada, Montréal, Canada
| | - Martin Morris
- Schulich Library of Physical Sciences, Life Sciences and Engineering, McGill University, Montréal, Canada
| | - Svetlana V Komarova
- Shriners Hospitals for Children - Canada, Montréal, Canada.
- Faculty of Dentistry, McGill University, Montréal, Canada.
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10
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Gamboa A, Branscum AJ, Olson DA, Sattgast LH, Iwaniec UT, Turner RT. Effects of spaceflight on cancellous and cortical bone in proximal femur in growing rats. Bone Rep 2021; 14:100755. [PMID: 33665238 PMCID: PMC7907224 DOI: 10.1016/j.bonr.2021.100755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 02/01/2021] [Accepted: 02/10/2021] [Indexed: 11/25/2022] Open
Abstract
Mechanical loading of the skeleton during normal weight bearing plays an important role in bone accrual and turnover balance. We recently evaluated bone microarchitecture in the femoral head in 5.6-week-old male Sprague Dawley rats subjected to a 4-day spaceflight aboard STS-41. Compared to weight bearing ground controls, cancellous bone volume fraction was dramatically lower in animals subjected to microgravity. The effects of spaceflight on the rat skeleton are potentially influenced by factors such as age, duration of flight, strain and sex. To test the generalizability of our initial observation, we evaluated archived proximal femora from two additional spaceflight missions: a 10-day mission (STS-57) with 7.5-week-old male Fisher 344 rats, and a 14-day mission (STS-62) with 12-week-old ovariectomized (ovx) female Fisher 344 rats. Cancellous microarchitecture and cortical thickness were assessed using x-ray microtomography/microcomputed tomography. In male rats, cancellous bone volume fraction (bone volume/tissue volume) was lower in flight animals compared to flight controls, but differences were not significant compared to baseline. In ovx female rats, cancellous bone volume fraction was lower in flight animals compared to flight controls and baseline, indicating net bone loss. Cortical thickness did not differ among groups in either experiment. In summary, findings from three separate studies support the conclusion that spaceflight results in cancellous osteopenia in femoral head of growing rats. Spaceflight resulted in cancellous osteopenia in femoral head of growing rats. Osteopenia was observed in female ovariectomized and male Fisher 344 rats. The femoral head should be evaluated in future spaceflight experiments.
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Affiliation(s)
- Amanda Gamboa
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Adam J Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Dawn A Olson
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Lara H Sattgast
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA.,Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA
| | - Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA.,Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA
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11
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Coulombe JC, Senwar B, Ferguson VL. Spaceflight-Induced Bone Tissue Changes that Affect Bone Quality and Increase Fracture Risk. Curr Osteoporos Rep 2020; 18:1-12. [PMID: 31897866 DOI: 10.1007/s11914-019-00540-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE OF REVIEW Bone mineral density and systemic factors are used to assess skeletal health in astronauts. Yet, even in a general population, these measures fail to accurately predict when any individual will fracture. This review considers how long-duration human spaceflight requires evaluation of additional bone structural and material quality measures that contribute to microgravity-induced skeletal fragility. RECENT FINDINGS In both humans and small animal models following spaceflight, bone mass is compromised via reduced bone formation and elevated resorption levels. Concurrently, bone structural quality (e.g., trabecular microarchitecture) is diminished and the quality of bone material is reduced via impaired tissue mineralization, maturation, and maintenance (e.g., mediated by osteocytes). Bone structural and material quality are both affected by microgravity and may, together, jeopardize astronaut operational readiness and lead to increased fracture risk upon return to gravitational loading. Future studies need to directly evaluate how bone quality combines with diminished bone mass to influence bone strength and toughness (e.g., resistance to fracture). Bone quality assessment promises to identify novel biomarkers and therapeutic targets.
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Affiliation(s)
- Jennifer C Coulombe
- Department of Mechanical Engineering, University of Colorado, UCB 427, Boulder, CO, 80309, USA
- BioFrontiers Institute, University of Colorado, UCB 596, Boulder, CO, 80309, USA
- BioServe Space Technologies, University of Colorado, UCB 429, Boulder, CO, 80309, USA
| | - Bhavya Senwar
- Department of Mechanical Engineering, University of Colorado, UCB 427, Boulder, CO, 80309, USA
- BioFrontiers Institute, University of Colorado, UCB 596, Boulder, CO, 80309, USA
- BioServe Space Technologies, University of Colorado, UCB 429, Boulder, CO, 80309, USA
| | - Virginia L Ferguson
- Department of Mechanical Engineering, University of Colorado, UCB 427, Boulder, CO, 80309, USA.
- BioFrontiers Institute, University of Colorado, UCB 596, Boulder, CO, 80309, USA.
- BioServe Space Technologies, University of Colorado, UCB 429, Boulder, CO, 80309, USA.
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12
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Martin SA, Philbrick KA, Wong CP, Olson DA, Branscum AJ, Jump DB, Marik CK, DenHerder JM, Sargent JL, Turner RT, Iwaniec UT. Thermoneutral housing attenuates premature cancellous bone loss in male C57BL/6J mice. Endocr Connect 2019; 8:1455-1467. [PMID: 31590144 PMCID: PMC6865368 DOI: 10.1530/ec-19-0359] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 10/07/2019] [Indexed: 12/12/2022]
Abstract
Mice are a commonly used model to investigate aging-related bone loss but, in contrast to humans, mice exhibit cancellous bone loss prior to skeletal maturity. The mechanisms mediating premature bone loss are not well established. However, our previous work in female mice suggests housing temperature is a critical factor. Premature cancellous bone loss was prevented in female C57BL/6J mice by housing the animals at thermoneutral temperature (where basal rate of energy production is at equilibrium with heat loss). In the present study, we determined if the protective effects of thermoneutral housing extend to males. Male C57BL/6J mice were housed at standard room temperature (22°C) or thermoneutral (32°C) conditions from 5 (rapidly growing) to 16 (slowly growing) weeks of age. Mice housed at room temperature exhibited reductions in cancellous bone volume fraction in distal femur metaphysis and fifth lumbar vertebra; these effects were abolished at thermoneutral conditions. Mice housed at thermoneutral temperature had higher levels of bone formation in distal femur (based on histomorphometry) and globally (serum osteocalcin), and lower global levels of bone resorption (serum C-terminal telopeptide of type I collagen) compared to mice housed at room temperature. Thermoneutral housing had no impact on bone marrow adiposity but resulted in higher abdominal white adipose tissue and serum leptin. The overall magnitude of room temperature housing-induced cancellous bone loss did not differ between male (current study) and female (published data) mice. These findings highlight housing temperature as a critical experimental variable in studies using mice of either sex to investigate aging-related changes in bone metabolism.
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Affiliation(s)
- Stephen A Martin
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Kenneth A Philbrick
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Carmen P Wong
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Dawn A Olson
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Adam J Branscum
- Biostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Donald B Jump
- Molecular Nutrition and Diabetes Research Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Charles K Marik
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Jonathan M DenHerder
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Jennifer L Sargent
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
| | - Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
- Center for Healthy Aging Research, Oregon State University, Corvallis, Oregon, USA
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA
- Center for Healthy Aging Research, Oregon State University, Corvallis, Oregon, USA
- Correspondence should be addressed to U T Iwaniec:
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13
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Trudel G, Melkus G, Sheikh A, Ramsay T, Laneuville O. Marrow adipose tissue gradient is preserved through high protein diet and bed rest. A randomized crossover study. Bone Rep 2019; 11:100229. [PMID: 31799339 PMCID: PMC6883331 DOI: 10.1016/j.bonr.2019.100229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 10/21/2019] [Indexed: 12/17/2022] Open
Abstract
Context Marrow adipose tissue (MAT) has a peripheral to central distribution in adults, higher in peripheral bones. Similarly, the spine has a caudal to cephalad MAT distribution, higher in lumbar vertebras. Diet and the level of physical activities are known modulators of MAT with significant impact on bone; however, whether these can modulate the MAT gradient is unknown. Objective To measure the effect of high protein diet and bed rest interventions on the lumbar MAT gradient. Design participants intervention In a prospective randomized crossover trial, 10 healthy men participated in 2 consecutive campaigns of 21days head-down-tilt-bed-rest (HDTBR). They received either whey protein and potassium bicarbonate-supplemented or control diet separated by a 4-month washout period. Main outcome measures Ten serial MRI measures of lumbar vertebral fat fraction (VFF) were performed at baseline, 10days and 20days of HDTBR and 3 and 28days after HDTBR of each bed rest campaign. Results The mean L5-L1 VFF difference of 4.2 ± 1.2 percentage point higher at L5 (p = 0.008) constituted a caudal to cephalad lumbar MAT gradient. High protein diet did not alter the lumbar VFF differences during both HDTBR campaigns (all time points p > 0.05). Similarly, 2 campaigns of 21days of HDTBR did not change the lumbar VFF differences (all time points p > 0.05). Conclusions This pilot study established that the lumbar vertebral MAT gradient was not altered by a high protein nor by 2 × 21days bed rest interventions. These findings demonstrated that this lack of mechanical stimulus was not an important modulator of the lumbar MAT gradient. The highly preserved MAT gradient needs to be measured in more situations of health and disease and may potentially serve to detect pathological situations.
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Key Words
- BDC, baseline data collection
- Bed rest study
- DLR, German Aerospace Center
- FOV, field of view
- HDT, head-down tilt
- HDTBR, head-down-tilt-bed-rest
- IOP, in-phase and out-phase imaging
- Lumbar vertebral fat fraction
- MAT, marrow adipose tissue
- MEP, whey protein study
- MR, magnetic resonance
- Magnetic resonance imaging
- Marrow adipose tissue
- PDFF, proton-density fat fraction
- R, recovery
- ROI, region of interest
- TR, repetition time
- VFF, vertebral fat fraction
- Whey protein
- in-phase, echo time 1 (TE1)
- out-phase, echo time 2 (TE2)
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Affiliation(s)
- Guy Trudel
- Bone and Joint Research Laboratory, Department of Physical Medicine and Rehabilitation, Department of Medicine, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada.,The Ottawa Hospital Research Institute, Ontario, Canada
| | - Gerd Melkus
- The Ottawa Hospital Research Institute, Ontario, Canada.,Department of Radiology, University of Ottawa, Ontario, Canada
| | - Adnan Sheikh
- The Ottawa Hospital Research Institute, Ontario, Canada.,Department of Radiology, University of Ottawa, Ontario, Canada
| | - Tim Ramsay
- The Ottawa Hospital Research Institute, Ontario, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ontario, Canada
| | - Odette Laneuville
- Bone and Joint Research Laboratory, Department of Physical Medicine and Rehabilitation, Department of Medicine, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada.,Department of Biology, Faculty of Science, University of Ottawa, Ontario, Canada
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14
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Keune JA, Branscum AJ, Wong CP, Iwaniec UT, Turner RT. Effect of Leptin Deficiency on the Skeletal Response to Hindlimb Unloading in Adult Male Mice. Sci Rep 2019; 9:9336. [PMID: 31249331 PMCID: PMC6597714 DOI: 10.1038/s41598-019-45587-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/06/2019] [Indexed: 12/29/2022] Open
Abstract
Based on body weight, morbidly obese leptin-deficient ob/ob mice have less bone than expected, suggesting that leptin plays a role in the skeletal response to weight bearing. To evaluate this possibility, we compared the skeletal response of wild type (WT) and ob/ob mice to hindlimb unloading (HU). Mice were individually housed at 32 °C (thermoneutral) from 4 weeks of age (rapidly growing) to 16 weeks of age (approaching skeletal maturity). Mice were then randomized into one of 4 groups (n = 10/group): (1) WT control, (2) WT HU, (3) ob/ob control, and (4) ob/ob HU and the results analyzed by 2-way ANOVA. ob/ob mice pair-fed to WT mice had normal cancellous bone volume fraction (BV/TV) in distal femur, lower femur length and total bone area, mineral content (BMC) and density (BMD), and higher cancellous bone volume fraction in lumbar vertebra (LV). HU resulted in lower BMC and BMD in total femur, and lower BV/TV in distal femur and LV in both genotypes. Cancellous bone loss in femur in both genotypes was associated with increases in osteoclast-lined bone perimeter. In summary, leptin deficiency did not attenuate HU-induced osteopenia in male mice, suggesting that leptin is not required for bone loss induced by unweighting.
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Affiliation(s)
- Jessica A. Keune
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Adam J. Branscum
- 0000 0001 2112 1969grid.4391.fBiostatistics Program, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Carmen P. Wong
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA
| | - Urszula T. Iwaniec
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA ,0000 0001 2112 1969grid.4391.fCenter for Healthy Aging Research, Oregon State University, Corvallis, OR 97331 USA
| | - Russell T. Turner
- 0000 0001 2112 1969grid.4391.fSkeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331 USA ,0000 0001 2112 1969grid.4391.fCenter for Healthy Aging Research, Oregon State University, Corvallis, OR 97331 USA
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15
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Smith JK. IL-6 and the dysregulation of immune, bone, muscle, and metabolic homeostasis during spaceflight. NPJ Microgravity 2018; 4:24. [PMID: 30534586 PMCID: PMC6279793 DOI: 10.1038/s41526-018-0057-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 10/10/2018] [Indexed: 01/08/2023] Open
Abstract
We have previously reported that exercise-related secretion of IL-6 by peripheral blood mononuclear cells is proportionate to body weight, suggesting that IL-6 is gravisensitive and that suboptimal production of this key cytokine may contribute to homeostatic dysregulations that occur during spaceflight. This review details what is known about the role of this key cytokine in innate and adaptive immunity, hematopoiesis, and in bone, muscle and metabolic homeostasis on Earth and in the microgravity of space and suggests an experimental approach to confirm or disavow the role of IL-6 in space-related dysregulations.
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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, Johnson City, TN USA
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16
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Li WY, Li XY, Tian YH, Chen XR, Zhou J, Zhu BY, Xi HR, Gao YH, Xian CJ, Chen KM. Pulsed electromagnetic fields prevented the decrease of bone formation in hindlimb-suspended rats by activating sAC/cAMP/PKA/CREB signaling pathway. Bioelectromagnetics 2018; 39:569-584. [PMID: 30350869 DOI: 10.1002/bem.22150] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 09/30/2018] [Indexed: 12/21/2022]
Abstract
Microgravity is one of the main threats to the health of astronauts. Pulsed electromagnetic fields (PEMFs) have been considered as one of the potential countermeasures for bone loss induced by space flight. However, the optimal therapeutic parameters of PEMFs have not been obtained and the action mechanism is still largely unknown. In this study, a set of optimal therapeutic parameters for PEMFs (50 Hz, 0.6 mT 50% duty cycle and 90 min/day) selected based on high-throughput screening with cultured osteoblasts was used to prevent bone loss in rats induced by hindlimb suspension, a commonly accepted animal model to simulate the space environment. It was found that hindlimb suspension for 4 weeks led to significant decreases in femoral and vertebral bone mineral density (BMD) and their maximal loads, severe deterioration in bone micro-structure, and decreases in levels of bone formation markers and increases in bone resorption markers. PEMF treatment prevented about 50% of the decreased BMD and maximal loads, preserved the microstructure of cancellous bone and thickness of cortical bone, and inhibited decreases in bone formation markers. Histological analyses revealed that PEMFs significantly alleviated the reduction in osteoblast number and inhibited the increase in adipocyte number in the bone marrow. PEMFs also blocked decreases in serum levels of parathyroid hormone and its downstream signal molecule cAMP, and maintained the phosphorylation levels of protein kinase A (PKA) and cAMP response element-binding protein (CREB). The expression level of soluble adenylyl cyclases (sAC) was also maintained. It therefore can be concluded that PEMFs partially prevented the bone loss induced by weightless environment by maintaining bone formation through signaling of the sAC/cAMP/PKA/CREB pathway. Bioelectromagnetics. 39:569-584, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Wen-Yuan Li
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China.,Institute of Orthopaedics, Lanzhou General Hospital of CPLA, Lanzhou, China
| | - Xue-Yan Li
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
| | - Yong-Hui Tian
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
| | - Xin-Ru Chen
- College of Life Sciences, Northwest A & F University, Yanglin, China
| | - Jian Zhou
- Institute of Orthopaedics, Lanzhou General Hospital of CPLA, Lanzhou, China
| | - Bao-Ying Zhu
- Institute of Orthopaedics, Lanzhou General Hospital of CPLA, Lanzhou, China
| | - Hui-Rong Xi
- Institute of Orthopaedics, Lanzhou General Hospital of CPLA, Lanzhou, China
| | - Yu-Hai Gao
- Institute of Orthopaedics, Lanzhou General Hospital of CPLA, Lanzhou, China
| | - Cory J Xian
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Ke-Ming Chen
- Institute of Orthopaedics, Lanzhou General Hospital of CPLA, Lanzhou, China
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Abstract
PURPOSE OF REVIEW Mesenchymal stem cells (MSCs) located in the bone marrow have the capacity to differentiate into multiple cell lineages, including osteoblast and adipocyte. Adipocyte density within marrow is inversely associated with bone mass during aging and in some pathological conditions, contributing to the prevailing view that marrow adipocytes play a largely negative role in bone metabolism. However, a negative association between marrow adipocytes and bone balance is not universal. Although MAT levels appear tightly regulated, establishing the precise physiological significance of MAT has proven elusive. Here, we review recent literature aimed at delineating the function of MAT. RECENT FINDINGS An important physiological function of MAT may be to provide an expandable/contractible fat depot, which is critical for minimization of energy requirements for sustaining optimal hematopoiesis. Because the energy requirements for storing fat are negligible compared to those required to maintain hematopoiesis, even small reductions in hematopoietic tissue volume to match a reduced requirement for hematopoiesis could represent an important reduction in energy cost. Such a physiological function would require tight coupling between hematopoietic stem cells and MSCs to regulate the balance between MAT and hematopoiesis. Kit-ligand, an important regulator of proliferation, differentiation, and survival of hematopoietic cells, may function as a prototypic factor coupling MAT and hematopoiesis. Crosstalk between hematopoietic and mesenchymal cells in the bone marrow may contribute to establishing the balance between MAT levels and hematopoiesis.
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Affiliation(s)
- Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
- Center for Healthy Aging Research, Oregon State University, Corvallis, OR, 97331, USA
| | - Stephen A Martin
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, 97331, USA.
- Center for Healthy Aging Research, Oregon State University, Corvallis, OR, 97331, USA.
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18
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Bone Marrow Adipose Tissue Deficiency Increases Disuse-Induced Bone Loss in Male Mice. Sci Rep 2017; 7:46325. [PMID: 28402337 PMCID: PMC5389344 DOI: 10.1038/srep46325] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 03/16/2017] [Indexed: 12/17/2022] Open
Abstract
Bone marrow adipose tissue (MAT) is negatively associated with bone mass. Since osteoblasts and adipocytes are derived from the same precursor cells, adipocyte differentiation may occur at the expense of osteoblast differentiation. We used MAT-deficient KitW/W−v (MAT-) mice to determine if absence of MAT reduced bone loss in hindlimb-unloaded (HU) mice. Male MAT- and wild-type (WT) mice were randomly assigned to a baseline, control or HU group (n = 10 mice/group) within each genotype and HU groups unloaded for 2 weeks. Femurs were evaluated using micro-computed tomography, histomorphometry and targeted gene profiling. MAT- mice had a greater reduction in bone volume fraction after HU than did WT mice. HU MAT- mice had elevated cancellous bone formation and resorption compared to other treatment groups as well as a unique profile of differentially expressed genes. Adoptive transfer of WT bone marrow-derived hematopoietic stem cells reconstituted c-kit but not MAT in KitW/W−v mice. The MAT- WT → KitW/W−v mice lost cancellous bone following 2 weeks of HU. In summary, results from this study suggest that MAT deficiency was not protective, and was associated with exaggerated disuse-induced cancellous bone loss.
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19
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Iwaniec UT, Turner RT. Influence of body weight on bone mass, architecture and turnover. J Endocrinol 2016; 230:R115-30. [PMID: 27352896 PMCID: PMC4980254 DOI: 10.1530/joe-16-0089] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/27/2016] [Indexed: 12/11/2022]
Abstract
Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating the development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. Although the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size.
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Affiliation(s)
- Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| | - Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
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