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Bone metabolism during strict head-down tilt bed rest and exposure to elevated levels of ambient CO 2. NPJ Microgravity 2022; 8:57. [PMID: 36526672 PMCID: PMC9758179 DOI: 10.1038/s41526-022-00245-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 11/03/2022] [Indexed: 12/23/2022] Open
Abstract
Astronauts on the International Space Station are exposed to levels of atmospheric carbon dioxide (CO2) above typical terrestrial levels. We explored the possibility that increased levels of ambient CO2 further stimulate bone resorption during bed rest. We report here data from 2 ground-based spaceflight analog studies in which 12 male and 7 female subjects were placed in a strict 6° head-down tilt (HDT) position for either 30 days at 0.5% ambient CO2 or 60 days with nominal environmental exposure to CO2. Bone mineral density (BMD) and bone mineral content (BMC) were determined using dual-energy X-ray absorptiometry (DXA). Blood and urine were collected before and after HDT for biochemical analysis. No change was detected in either BMD or BMC, as expected given the study duration. Bone resorption markers increased after bed rest as expected; however, elevated CO2 had no additive effect. Elevated CO2 did not affect concentrations of minerals in serum and urine. Serum parathyroid hormone and 1,25-dihydroxyvitamin D were both reduced after bed rest, likely secondary to calcium efflux from bone. In summary, exposure to 0.5% CO2 for 30 days did not exacerbate the typical bone resorption response observed after HDT bed rest. Furthermore, results from these strict HDT studies were similar to data from previous bed rest studies, confirming that strict 30-60 days of HDT can be used to evaluate changes in bone metabolism. This is valuable in the continuing effort to develop and refine efficacious countermeasure protocols to mitigate bone loss during spaceflight in low-Earth orbit and beyond.
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Man J, Graham T, Squires-Donelly G, Laslett AL. The effects of microgravity on bone structure and function. NPJ Microgravity 2022; 8:9. [PMID: 35383182 PMCID: PMC8983659 DOI: 10.1038/s41526-022-00194-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 03/04/2022] [Indexed: 12/22/2022] Open
Abstract
Humans are spending an increasing amount of time in space, where exposure to conditions of microgravity causes 1-2% bone loss per month in astronauts. Through data collected from astronauts, as well as animal and cellular experiments conducted in space, it is evident that microgravity induces skeletal deconditioning in weight-bearing bones. This review identifies contentions in current literature describing the effect of microgravity on non-weight-bearing bones, different bone compartments, as well as the skeletal recovery process in human and animal spaceflight data. Experiments in space are not readily available, and experimental designs are often limited due to logistical and technical reasons. This review introduces a plethora of on-ground research that elucidate the intricate process of bone loss, utilising technology that simulates microgravity. Observations from these studies are largely congruent to data obtained from spaceflight experiments, while offering more insights behind the molecular mechanisms leading to microgravity-induced bone loss. These insights are discussed herein, as well as how that knowledge has contributed to studies of current therapeutic agents. This review also points out discrepancies in existing data, highlighting knowledge gaps in our current understanding. Further dissection of the exact mechanisms of microgravity-induced bone loss will enable the development of more effective preventative and therapeutic measures to protect against bone loss, both in space and possibly on ground.
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Affiliation(s)
- Joey Man
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia.
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia.
- Space Technology Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria, 3168, Australia.
| | - Taylor Graham
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia
| | - Georgina Squires-Donelly
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia
| | - Andrew L Laslett
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Clayton, Victoria, 3168, Australia.
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, 3800, Australia.
- Space Technology Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria, 3168, Australia.
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Abstract
PURPOSE OF REVIEW Osteocytes are considered to be the cells responsible for mastering the remodeling process that follows the exposure to unloading conditions. Given the invasiveness of bone biopsies in humans, both rodents and in vitro culture systems are largely adopted as models for studies in space missions or in simulated microgravity conditions models on Earth. RECENT FINDINGS After a brief recall of the main changes in bone mass and osteoclastic and osteoblastic activities in space-related models, this review focuses on the potential role of osteocytes in directing these changes. The role of the best-known signalling molecules is questioned, in particular in relation to osteocyte apoptosis. The mechanotransduction actors identified in spatial conditions and the problems related to fluid flow and shear stress changes, probably enhanced by the alteration in fluid flow and lack of convection during spaceflight, are recalled and discussed.
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Affiliation(s)
- Donata Iandolo
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France
| | - Maura Strigini
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France
| | - Alain Guignandon
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France
| | - Laurence Vico
- U1059 INSERM - SAINBIOSE (SAnté INgéniérie BIOlogie St-Etienne) Campus Santé Innovation, Université Jean Monnet, Saint-Priest-en-Jarez, France.
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Linossier MT, Amirova LE, Thomas M, Normand M, Bareille MP, Gauquelin-Koch G, Beck A, Costes-Salon MC, Bonneau C, Gharib C, Custaud MA, Vico L. Effects of short-term dry immersion on bone remodeling markers, insulin and adipokines. PLoS One 2017; 12:e0182970. [PMID: 28806419 PMCID: PMC5555617 DOI: 10.1371/journal.pone.0182970] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/27/2017] [Indexed: 12/21/2022] Open
Abstract
Background Dry immersion (DI), a ground-based model of microgravity previously used in Russia, has been recently implemented in France. The aim of this study was to analyze early events in a short-term DI model in which all conditions are met to investigate who is first challenged from osteo- or adipo-kines and to what extent they are associated to insulin-regulating hormones. Methods Twelve healthy men were submitted to a 3-day DI. Fasting blood was collected during pre-immersion phase for the determination of the baseline data collection (BDC), daily during DI (DI24h, DI48H and DI72h), then after recovery (R+3h and R+24h). Markers of bone turnover, phosphocalcic metabolism, adipokines and associated factors were measured. Results Bone resorption as assessed by tartrate-resistant acid phosphatase isoform 5b and N-terminal crosslinked telopeptide of type I collagen levels increased as early as DI24h. At the same time, total procollagen type I N- and C-terminal propeptides and osteoprotegerin, representing bone formation markers, decreased. Total osteocalcin [OC] was unaffected, but its undercarboxylated form [Glu-OC] increased from DI24h to R+3h. The early and progressive increase in bone alkaline phosphatase activities suggested an increased mineralization. Dickkopf-1 and sclerostin, as negative regulators of the Wnt-β catenin pathway, were unaltered. No change was observed either in phosphocalcic homeostasis (calcium and phosphate serum levels, 25-hydroxyvitamin D, fibroblast growth factor 23 [FGF23]) or in inflammatory response. Adiponectemia was unchanged, whereas circulating leptin concentrations increased. Neutrophil gelatinase-associated lipocalin [lipocalin-2], a potential regulator of bone homeostasis, was found elevated by 16% at R+3h compared to DI24h. The secretory form of nicotinamide phosphoribosyl-transferase [visfatin] concentrations almost doubled after one day of DI and remained elevated. Serum insulin-like growth factor 1 levels progressively increased. Fasting insulin concentrations increased during the entire DI, whereas fasting glucose levels tended to be higher only at DI24h and then returned to BDC values. Changes in bone resorption parameters negatively correlated with changes in bone formation parameters. Percent changes of ultra-sensitive C-reactive protein positively correlated with changes in osteopontin, lipocalin-2 and fasting glucose. Furthermore, a positive correlation was found between changes in FGF23 and Glu-OC, the two main osteoblast-/osteocyte-derived hormones. Conclusion Our results demonstrated that DI induced an unbalanced remodeling activity and the onset of insulin resistance. This metabolic adaptation was concomitant with higher levels of Glu-OC. This finding confirms the role of bone as an endocrine organ in humans. Furthermore, visfatin for which a great responsiveness was observed could represent an early and sensitive marker of unloading in humans.
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Affiliation(s)
- Marie-Thérèse Linossier
- University of Lyon, Medicine Faculty of Saint-Etienne, INSERM, UMR 1059, Saint Etienne, France
- * E-mail:
| | - Liubov E. Amirova
- University of Angers, Medicine Faculty, Mitovasc Laboratory, UMR CNRS 6015, INSERM 1083, Angers, France
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Mireille Thomas
- University of Lyon, Medicine Faculty of Saint-Etienne, INSERM, UMR 1059, Saint Etienne, France
| | - Myriam Normand
- University of Lyon, Medicine Faculty of Saint-Etienne, INSERM, UMR 1059, Saint Etienne, France
| | | | | | - Arnaud Beck
- Institute of Space Physiology and Medicine (MEDES), Toulouse, France
| | | | | | | | - Marc-Antoine Custaud
- University of Angers, Medicine Faculty, Mitovasc Laboratory, UMR CNRS 6015, INSERM 1083, Angers, France
- Clinical Research Center, CHU d'Angers, Angers, France
| | - Laurence Vico
- University of Lyon, Medicine Faculty of Saint-Etienne, INSERM, UMR 1059, Saint Etienne, France
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DiVasta AD, Feldman HA, Rubin CT, Gallagher JS, Stokes N, Kiel DP, Snyder BD, Gordon CM. The ability of low-magnitude mechanical signals to normalize bone turnover in adolescents hospitalized for anorexia nervosa. Osteoporos Int 2017; 28:1255-1263. [PMID: 27909781 PMCID: PMC9769086 DOI: 10.1007/s00198-016-3851-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/21/2016] [Indexed: 12/24/2022]
Abstract
UNLABELLED We sought to determine whether low-magnitude mechanical stimulation (LMMS) normalizes bone turnover among adolescents hospitalized for anorexia nervosa (AN). Brief, daily LMMS prevents the decline in bone turnover typically seen during bed rest in AN. LMMS may have application for patients with AN in the inpatient setting to protect bone health. INTRODUCTION Malnourished adolescents with AN requiring medical hospitalization are at high risk for rapid reduction in skeletal quality. Even short-term bed rest can suppress normal patterns of bone turnover. We sought to determine whether LMMS normalizes bone turnover among adolescents hospitalized for complications of AN. METHODS In this randomized, double-blind trial, we prospectively enrolled adolescent females (n = 41) with AN, age 16.3 ± 1.9 years (mean ± SD) and BMI 15.6 ± 1.7 kg/m2. Participants were randomized to stand on a platform delivering LMMS (0.3 g at 32-37 Hz) or placebo platform for 10 min/day for 5 days. Serum markers of bone formation [bone-specific alkaline phosphatase (BSAP)], turnover [osteocalcin (OC)], and bone resorption [serum C-telopeptides (CTx)] were measured. From a random coefficients model, we constructed estimates and confidence intervals for all outcomes. RESULTS BSAP decreased by 2.8% per day in the placebo arm (p = 0.03) but remained stable in the LMMS group (p = 0.51, pdiff = 0.04). CTx did not change with placebo (p = 0.56) but increased in the LMMS arm (+6.2% per day, p = 0.04; pdiff = 0.01). Serum OC did not change in either group (p > 0.70). CONCLUSIONS Bed rest during hospitalization for patients with AN is associated with a suppression of bone turnover, which may contribute to diminished bone quality. Brief, daily LMMS prevents a decline in bone turnover during bed rest in AN. Protocols prescribing strict bed rest may not be appropriate for protecting bone health for these patients. LMMS may have application for these patients in the inpatient setting.
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Affiliation(s)
- A D DiVasta
- Division of Adolescent Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
- Division of Gynecology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
| | - H A Feldman
- Clinical Research Program, Boston Children's Hospital, Boston, MA, USA
| | - C T Rubin
- Department of Biomedical Engineering, State University of New York Stony Brook, Stony Brook, NY, USA
| | - J S Gallagher
- Division of Adolescent Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - N Stokes
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - D P Kiel
- Institute for Aging Research, Hebrew SeniorLife, Roslindale, MA, USA
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - B D Snyder
- Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - C M Gordon
- Division of Adolescent and Transition Medicine, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Marmonti E, Busquets S, Toledo M, Ricci M, Beltrà M, Gudiño V, Oliva F, López-Pedrosa JM, Manzano M, Rueda R, López-Soriano FJ, Argilés JM. A Rat Immobilization Model Based on Cage Volume Reduction: A Physiological Model for Bed Rest? Front Physiol 2017; 8:184. [PMID: 28424626 PMCID: PMC5372807 DOI: 10.3389/fphys.2017.00184] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 03/10/2017] [Indexed: 11/13/2022] Open
Abstract
Bed rest has been an established treatment in the past prescribed for critically illness or convalescing patients, in order to preserve their body metabolic resource, to prevent serious complications and to support their rapid path to recovery. However, it has been reported that prolonged bed rest can have detrimental consequences that may delay or prevent the recovery from clinical illness. In order to study disuse-induced changes in muscle and bone, as observed during prolonged bed rest in humans, an innovative new model of muscle disuse for rodents is presented. Basically, the animals are confined to a reduced space designed to restrict their locomotion movements and allow them to drink and eat easily, without generating physical stress. The animals were immobilized for either 7, 14, or 28 days. The immobilization procedure induced a significant decrease of food intake, both at 14 and 28 days of immobilization. The reduced food intake was not a consequence of a stress condition induced by the model since plasma corticosterone levels –an indicator of a stress response– were not altered following the immobilization period. The animals showed a significant decrease in soleus muscle mass, grip force and cross-sectional area (a measure of fiber size), together with a decrease in bone mineral density. The present model may potentially serve to investigate the effects of bed-rest in pathological states characterized by a catabolic condition, such as diabetes or cancer.
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Affiliation(s)
- Enrica Marmonti
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain
| | - Sílvia Busquets
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain.,Institut de Biomedicina de la Universitat de BarcelonaBarcelona, Spain
| | - Míriam Toledo
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain
| | - Marina Ricci
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain
| | - Marc Beltrà
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain
| | - Victòria Gudiño
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain
| | - Francesc Oliva
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística, Universitat de BarcelonaBarcelona, Spain
| | | | | | | | - Francisco J López-Soriano
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain.,Institut de Biomedicina de la Universitat de BarcelonaBarcelona, Spain
| | - Josep M Argilés
- Cancer Research Group, Facultat de Biologia, Departament de Bioquímica i Biomedicina Molecular, Universitat de BarcelonaBarcelona, Spain.,Institut de Biomedicina de la Universitat de BarcelonaBarcelona, Spain
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7
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Martin SPK, Bachrach LK, Golden NH. Controlled Pilot Study of High-Impact Low-Frequency Exercise on Bone Loss and Vital-Sign Stabilization in Adolescents With Eating Disorders. J Adolesc Health 2017; 60:33-37. [PMID: 27836532 DOI: 10.1016/j.jadohealth.2016.08.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 08/13/2016] [Accepted: 08/15/2016] [Indexed: 11/24/2022]
Abstract
PURPOSE Adolescents with anorexia nervosa (AN) face an increased lifetime risk of bone fragility. This randomized controlled study examined the efficacy and safety of a high-impact activity program on markers of bone turnover and stabilization of vital signs (VSS). METHODS Forty-one hospitalized adolescents with AN were randomly assigned to routine care or routine care plus 20 jumps twice daily. Bone markers were measured at baseline days 1-3 (T1), days 4-6 (T2), and days 7-9 (T3). The primary outcome was change in bone-specific alkaline phosphatase (BSAP) at T3 adjusted for BSAP and % median body mass index at T1. Secondary outcomes were serum N-telopeptide (NTX) and osteocalcin at T3. Safety was determined by comparing weight gain, time to VSS and length of stay for each group. RESULTS BSAP, NTX, or osteocalcin did not differ between groups at baseline or at T3. BSAP and NTX at T3 were not associated with group of enrollment or % median body mass index. VSS was significantly reduced in the intervention group compared with the control group (11.6 ± 5.7 days vs. 17 ± 10.5 days, p = .049). There was no significant difference in weight gain or length of stay between groups. CONCLUSIONS Twice-daily jumping activity failed to influence markers of bone turnover in adolescents with AN but was well tolerated, shortened time to vital-sign stabilization and did not slow weight gain.
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Affiliation(s)
- Susanne P K Martin
- Division of Adolescent Medicine, Stanford University School of Medicine, Palo Alto, California.
| | - Laura K Bachrach
- Division of Pediatric Endocrinology, Stanford University School of Medicine, Palo Alto, California
| | - Neville H Golden
- Division of Adolescent Medicine, Stanford University School of Medicine, Palo Alto, California
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8
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Hargens AR, Vico L. Long-duration bed rest as an analog to microgravity. J Appl Physiol (1985) 2016; 120:891-903. [PMID: 26893033 DOI: 10.1152/japplphysiol.00935.2015] [Citation(s) in RCA: 185] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 02/12/2016] [Indexed: 11/22/2022] Open
Abstract
Long-duration bed rest is widely employed to simulate the effects of microgravity on various physiological systems, especially for studies of bone, muscle, and the cardiovascular system. This microgravity analog is also extensively used to develop and test countermeasures to microgravity-altered adaptations to Earth gravity. Initial investigations of bone loss used horizontal bed rest with the view that this model represented the closest approximation to inactivity and minimization of hydrostatic effects, but all Earth-based analogs must contend with the constant force of gravity by adjustment of the G vector. Later concerns about the lack of similarity between headward fluid shifts in space and those with horizontal bed rest encouraged the use of 6 degree head-down tilt (HDT) bed rest as pioneered by Russian investigators. Headward fluid shifts in space may redistribute bone from the legs to the head. At present, HDT bed rest with normal volunteers is the most common analog for microgravity simulation and to test countermeasures for bone loss, muscle and cardiac atrophy, orthostatic intolerance, and reduced muscle strength/exercise capacity. Also, current physiologic countermeasures are focused on long-duration missions such as Mars, so in this review we emphasize HDT bed rest studies with durations of 30 days and longer. However, recent results suggest that the HDT bed rest analog is less representative as an analog for other important physiological problems of long-duration space flight such as fluid shifts, spinal dysfunction and radiation hazards.
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Affiliation(s)
- Alan R Hargens
- Department of Orthopaedic Surgery, University of California, San Diego, San Diego, California; and Institut National de la Santé et de la Recherche Médicale Unité 1059, University of Lyon, St-Etienne, France
| | - Laurence Vico
- Department of Orthopaedic Surgery, University of California, San Diego, San Diego, California; and Institut National de la Santé et de la Recherche Médicale Unité 1059, University of Lyon, St-Etienne, France
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Smith S, Abrams S, Davis-Street J, Heer M, O'Brien K, Wastney M, Zwart S. Fifty Years of Human Space Travel: Implications for Bone and Calcium Research. Annu Rev Nutr 2014; 34:377-400. [DOI: 10.1146/annurev-nutr-071813-105440] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- S.M. Smith
- Biomedical Research and Environmental Sciences Division, NASA Lyndon B. Johnson Space Center, Houston, Texas 77058;
| | - S.A. Abrams
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030;
| | - J.E. Davis-Street
- Chevron Services Company, Corporate Health and Medical, Houston, Texas 77002;
| | - M. Heer
- Profil, 41460 Neuss, Germany;
- University of Bonn, Department of Nutrition and Food Science, Nutrition Physiology, 53115 Bonn, Germany
| | - K.O. O'Brien
- Cornell University, Division of Nutritional Sciences, Ithaca, New York 14853;
| | - M.E. Wastney
- Metabolic Modeling Services, West Lafayette, Indiana 47906;
| | - S.R. Zwart
- Division of Space Life Sciences, Universities Space Research Association, Houston, Texas 77058;
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10
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Kos O, Hughson RL, Hart DA, Clément G, Frings-Meuthen P, Linnarsson D, Paloski WH, Rittweger J, Wuyts F, Zange J, Gorczynski RM. Elevated serum soluble CD200 and CD200R as surrogate markers of bone loss under bed rest conditions. Bone 2014; 60:33-40. [PMID: 24333170 DOI: 10.1016/j.bone.2013.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 12/02/2013] [Accepted: 12/02/2013] [Indexed: 11/28/2022]
Abstract
CD200 is a transmembrane protein that belongs to the immunoglobulin family of proteins and is ubiquitously expressed on a variety of cell types. Upon interaction with its receptors (CD200Rs) expressed on myeloid-derived cells and T lymphocytes, an immunoregulatory signal is delivered to receptor-expressing cells. Previous studies have implicated a role for CD200:CD200R in the regulation of the expression of mRNA markers of osteoclastogenesis/osteoblastogenesis, following interaction of CD200 (on osteoblast precursors) with CD200R1 (on osteoclast precursors). Signaling of CD200R1 is hypothesized to attenuate osteoclastogenesis. We have investigated whether levels of soluble forms of CD200 and/or CD200R1 (sCD200, sCD200R1) are altered in volunteers undergoing 6° head down tilt bed rest to mimic conditions of microgravity known to be associated with preferential osteoclastogenesis and whether countermeasures, reported to be beneficial in attenuation of bone loss under microgravity conditions, would lead to altered sCD200 and sCD200R1 levels. Our data suggest that, as predicted, sCD200 levels fall under bed rest conditions while sCD200R1 levels rise. In subjects undergoing 30-minute per day continuous centrifugation protocols, as a countermeasure to attenuate changes which may lead to bone loss, these alterations in sCD200 and sCD200R1 levels seen under conditions of bed rest were abolished or attenuated. Our results suggest that measurement of sCD200 and/or sCD200R1 may prove a useful and rapid means of monitoring subjects at risk of bone loss and/or accessing the efficacy of treatment regimes designed to counter bone loss.
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Affiliation(s)
- O Kos
- Transplant Research Division, Toronto Hospital and University Health Network, 101 College St., Toronto, ON M5G1L7, Canada.
| | - R L Hughson
- Schlegel-University of Waterloo, Research Institute for Aging, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, ON N2L3G1, Canada.
| | - D A Hart
- McCaig Institute for Bone & Joint Health, 3330 Hospital Drive NW, Calgary, AB T2N4N1, Canada.
| | - G Clément
- International Space University, 1 rue Jean-Dominique Cassini, Illkirch-Graffenstaden F-67400, France.
| | - P Frings-Meuthen
- Institute for Aerospace Medicine, German Aerospace Center (DLR), Linder Höhe, Cologne D-51147, Germany.
| | - D Linnarsson
- Royal Institute of Technology, Stockholm SE-100 44, Sweden.
| | - W H Paloski
- University of Houston, 3855 Holman St., Rm 104, Garrison Houston, TX 77204-6015, USA.
| | - J Rittweger
- Institute for Aerospace Medicine, German Aerospace Center (DLR), Linder Höhe, Cologne D-51147, Germany; Institute for Biomedical Research into Human Movement and Health, Manchester Metropolitan University, Manchester M1 5GD, UK.
| | - F Wuyts
- Antwerp University Research Centre for Equilibrium and Aerospace, Middelheimcampus G.U.336, Groenenborgerlaan 171, Antwerpen B-2020, Belgium.
| | - J Zange
- Institute for Aerospace Medicine, German Aerospace Center (DLR), Linder Höhe, Cologne D-51147, Germany.
| | - R M Gorczynski
- Transplant Research Division, Toronto Hospital and University Health Network, 101 College St., Toronto, ON M5G1L7, Canada.
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11
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DiVasta AD, Gordon CM. Exercise and bone: where do we stand? Metabolism 2013; 62:1714-7. [PMID: 24140089 DOI: 10.1016/j.metabol.2013.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 09/17/2013] [Accepted: 09/17/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Amy D DiVasta
- Division of Adolescent and Young Adult Medicine, Boston Children's Hospital, 333 Longwood Avenue, Boston, MA 02115, USA; Division of Pediatric and Adolescent Gynecology, Boston Children's Hospital, Boston, MA 02115, USA.
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12
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Morgan JLL, Zwart SR, Heer M, Ploutz-Snyder R, Ericson K, Smith SM. Bone metabolism and nutritional status during 30-day head-down-tilt bed rest. J Appl Physiol (1985) 2012. [DOI: 10.115210.1152/japplphysiol.01064.2012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Bed rest studies provide an important tool for modeling physiological changes that occur during spaceflight. Markers of bone metabolism and nutritional status were evaluated in 12 subjects (8 men, 4 women; ages 25–49 yr) who participated in a 30-day −6° head-down-tilt diet-controlled bed rest study. Blood and urine samples were collected twice before, once a week during, and twice after bed rest. Data were analyzed using a mixed-effects linear regression with a priori contrasts comparing all days to the second week of the pre-bed rest acclimation period. During bed rest, all urinary markers of bone resorption increased ∼20% ( P < 0.001), and serum parathyroid hormone decreased ∼25% ( P < 0.001). Unlike longer (>60 days) bed rest studies, neither markers of oxidative damage nor iron status indexes changed over the 30 days of bed rest. Urinary oxalate excretion decreased ∼20% during bed rest ( P < 0.001) and correlated inversely with urinary calcium ( R = −0.18, P < 0.02). These data provide a broad overview of the biochemistry associated with short-duration bed rest studies and provide an impetus for using shorter studies to save time and costs wherever possible. For some effects related to bone biochemistry, short-duration bed rest will fulfill the scientific requirements to simulate spaceflight, but other effects (antioxidants/oxidative damage, iron status) do not manifest until subjects are in bed longer, in which case longer studies or other analogs may be needed. Regardless, maximizing research funding and opportunities will be critical to enable the next steps in space exploration.
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Affiliation(s)
- Jennifer L. L. Morgan
- Oak Ridge Associated Universities/NASA Post-Doctoral Fellow, NASA Johnson Space Center, Houston, Texas
| | - Sara R. Zwart
- Universities Space Research Association and NASA, NASA Johnson Space Center, Houston, Texas
| | - Martina Heer
- Department of Nutrition and Food Science, Nutritional Physiology, University of Bonn, Bonn, Germany
- Profil Institute for Metabolic Research, Neuss, Germany
| | - Robert Ploutz-Snyder
- Universities Space Research Association and NASA, NASA Johnson Space Center, Houston, Texas
| | - Karen Ericson
- Department of Chemistry, Indiana University-Purdue University Fort Wayne, Fort Wayne, Indiana; and
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Morgan JLL, Zwart SR, Heer M, Ploutz-Snyder R, Ericson K, Smith SM. Bone metabolism and nutritional status during 30-day head-down-tilt bed rest. J Appl Physiol (1985) 2012; 113:1519-29. [PMID: 22995395 PMCID: PMC3524659 DOI: 10.1152/japplphysiol.01064.2012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 09/18/2012] [Indexed: 11/22/2022] Open
Abstract
Bed rest studies provide an important tool for modeling physiological changes that occur during spaceflight. Markers of bone metabolism and nutritional status were evaluated in 12 subjects (8 men, 4 women; ages 25-49 yr) who participated in a 30-day -6° head-down-tilt diet-controlled bed rest study. Blood and urine samples were collected twice before, once a week during, and twice after bed rest. Data were analyzed using a mixed-effects linear regression with a priori contrasts comparing all days to the second week of the pre-bed rest acclimation period. During bed rest, all urinary markers of bone resorption increased ~20% (P < 0.001), and serum parathyroid hormone decreased ~25% (P < 0.001). Unlike longer (>60 days) bed rest studies, neither markers of oxidative damage nor iron status indexes changed over the 30 days of bed rest. Urinary oxalate excretion decreased ~20% during bed rest (P < 0.001) and correlated inversely with urinary calcium (R = -0.18, P < 0.02). These data provide a broad overview of the biochemistry associated with short-duration bed rest studies and provide an impetus for using shorter studies to save time and costs wherever possible. For some effects related to bone biochemistry, short-duration bed rest will fulfill the scientific requirements to simulate spaceflight, but other effects (antioxidants/oxidative damage, iron status) do not manifest until subjects are in bed longer, in which case longer studies or other analogs may be needed. Regardless, maximizing research funding and opportunities will be critical to enable the next steps in space exploration.
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Affiliation(s)
- Jennifer L L Morgan
- Oak Ridge Associated Universities, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77030, USA
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Abstract
Fractures resulting from osteoporosis are a major cause of morbidity and mortality in the developed world. People with multiple sclerosis experience reduced mobility and are susceptible to falls. Glucocorticoid use and reduced mobility are known risk factors for osteoporosis. This paper is a review of osteoporosis in people with multiple sclerosis, looking at its prevalence, risk factors and possible mechanisms. We also review management guidelines for osteoporosis in the general population and use these to propose guidelines for osteoporosis management amongst multiple sclerosis patients. A number of studies have examined the incidence of reduced bone mineral density amongst people with multiple sclerosis; the majority provide convincing evidence that bone mineral density is significantly reduced in multiple sclerosis patients. The most significant risk factors appear to arise from the chronic disease process of multiple sclerosis and not from glucocorticoid use. There are currently no guidelines or consensus as how best to treat osteoporosis amongst multiple sclerosis patients despite their being at an increased risk. We propose an algorithm for the screening and treatment of osteoporosis in people with multiple sclerosis.
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DiVasta AD, Feldman HA, Quach AE, Balestrino M, Gordon CM. The effect of bed rest on bone turnover in young women hospitalized for anorexia nervosa: a pilot study. J Clin Endocrinol Metab 2009; 94:1650-5. [PMID: 19223524 PMCID: PMC2684474 DOI: 10.1210/jc.2008-1654] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Malnourished adolescents with anorexia nervosa (AN) requiring medical hospitalization are at high risk for skeletal insults. Even short-term bed rest may further disrupt normal patterns of bone turnover. OBJECTIVE The objective of the study was to determine the effect of relative immobilization on bone turnover in adolescents hospitalized for AN. DESIGN This was a short-term observational study. SETTING The study was conducted at a tertiary care pediatric hospital. STUDY PARTICIPANTS Twenty-eight adolescents with AN, aged 13-21 yr with a mean body mass index of 15.9 +/- 1.8 kg/m(2), were enrolled prospectively on admission. INTERVENTION As per standard care, all subjects were placed on bed rest and graded nutritional therapy. MAIN OUTCOME MEASURE Markers of bone formation (bone specific alkaline phosphatase), turnover (osteocalcin), and bone resorption (urinary N-telopeptides NTx) were measured. RESULTS During the 5 d of hospitalization, serum osteocalcin increased by 0.24 +/- 0.1 ng/ml . d (P = 0.02). Urine N-telopeptides reached a nadir on d 3, declining -6.9 +/- 2.8 nm bone collagen equivalent per millimole creatinine (P = 0.01) but returned to baseline by d 5 (P > 0.05). Bone-specific alkaline phosphatase exhibited a decline that was strongly age dependent, being highly significant for younger subjects only [age 14 yr: -0.42 +/- 0.11 (P = 0.0002); age 18 yr: -0.03 +/- 0.08 (P = 0.68)]. Age had no effect on other outcome measures. CONCLUSION Limitation of physical activity during hospitalization for patients with AN is associated with suppressed bone formation and resorption and an imbalance of bone turnover. Future interventional studies involving mechanical stimulation and/or weight-bearing activity are needed to determine whether medical protocols prescribing strict bed rest are appropriate.
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Affiliation(s)
- Amy D DiVasta
- Division of Adolescent Medicine, Children's Hospital Boston, Boston, Massachusetts 02115, USA.
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Smith SM, Zwart SR, Heer MA, Baecker N, Evans HJ, Feiveson AH, Shackelford LC, Leblanc AD. Effects of artificial gravity during bed rest on bone metabolism in humans. J Appl Physiol (1985) 2008; 107:47-53. [PMID: 19074572 DOI: 10.1152/japplphysiol.91134.2008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We report results from a study designed to explore the utility of artificial gravity (AG) as a countermeasure to bone loss induced by microgravity simulation. After baseline testing, 15 male subjects underwent 21 days of 6 degrees head-down bed rest to simulate the deconditioning associated with spaceflight. Eight of the subjects underwent 1 h of centrifugation (AG; 1 G(z) at the heart, 2.5 G(z) at the feet) each day for 21 days, whereas seven of the subjects served as untreated controls (Con). Blood and urine were collected before, during, and after bed rest for bone marker determinations. Bone mineral density (BMD) and bone mineral content (BMC) were determined by dual-energy X-ray absorptiometry and peripheral quantitative computerized tomography before and after bed rest. Urinary excretion of bone resorption markers increased during bed rest, but the AG and Con groups did not differ significantly. The same was true for serum C-telopeptide. During bed rest, bone alkaline phosphatase (ALP) and total ALP tended to be lower in the AG group (P = 0.08, P = 0.09). Neither BMC nor BMD changed significantly from the pre-bed rest period in AG or Con groups, and the two groups were not significantly different. However, when AG and Con data were combined, there was a significant (P < 0.05) effect of time for whole body total BMC and total hip and trochanter BMD. These data failed to demonstrate efficacy of this AG prescription to prevent the changes in bone metabolism observed during 3 wk of bed rest.
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Affiliation(s)
- S M Smith
- Human Adaptation and Countermeasures Division, NASA Johnson Space Center, Houston, TX 77058, USA.
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Abstract
As we approach the end of the first 50 years of human space travel, much has been learned about adaptation to microgravity and the risks associated with extended-duration space exploration. As the frequency and duration of flights grew, nutrition issues became more critical and the questions to be answered became more complex: What are the nutrient requirements for space travelers? Can nutrients be used as tools to mitigate the negative effects of space travel on humans? How does nutrition interrelate with other physiological systems (such as muscle, bone, and cardiovascular system) and their adaptation to microgravity? Much research has been done over the decades in both actual spaceflight and ground-based analogs. We review here much of what is known, and highlight areas of ongoing research and concerns for future exploration of the Moon, Mars, and beyond.
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Affiliation(s)
- Scott M Smith
- Human Adaptation and Countermeasures Division, National Aeronautics and Space Administration, Johnson Space Center, Houston, Texas 77058, USA
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Smith SM, Zwart SR, Heer M, Lee SMC, Baecker N, Meuche S, Macias BR, Shackelford LC, Schneider S, Hargens AR. WISE-2005: supine treadmill exercise within lower body negative pressure and flywheel resistive exercise as a countermeasure to bed rest-induced bone loss in women during 60-day simulated microgravity. Bone 2008; 42:572-81. [PMID: 18249055 DOI: 10.1016/j.bone.2007.11.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Revised: 11/16/2007] [Accepted: 11/29/2007] [Indexed: 11/19/2022]
Abstract
Bone loss associated with disuse during bed rest (BR), an analog of space flight, can be attenuated by exercise. In previous studies, the efficacy of either aerobic or resistive exercise countermeasures has been examined separately. We hypothesized that a regimen of combined resistive and aerobic exercise during BR would prevent bone resorption and promote bone formation. After a 20-day ambulatory adaptation to controlled confinement and diet, 16 women participated in a 60-day, 6 degrees head-down-tilt BR and were assigned randomly to one of the two groups. Control subjects (CON, n=8) performed no countermeasure. Exercise subjects (EX, n=8) participated in an exercise program during BR, alternating between supine treadmill exercise within lower body negative pressure (3-4 d wk(-1)) and flywheel resistive exercise (2-3 d wk(-1)). By the last week of BR, excretion of helical peptide (CON, 79%+/-44 increase; EX, 64%+/-50, mean+/-SD) and N-terminal cross-linking telopeptide (CON, 51%+/-34; EX, 43%+/-56), markers of bone resorption, were greater than they were before BR in both groups (P<0.05). However, serum concentrations of the bone formation marker procollagen type I N propeptide were greater in EX than CON throughout and after bed rest (P<0.05), while concentrations of the bone formation marker bone alkaline phosphatase tended to be greater in EX than CON. Dual-energy X-ray absorptiometry results indicated that the exercise treatment significantly (P<0.05) attenuated loss of hip and leg bone mineral density in EX compared to CON. The combination of resistive and aerobic exercise did not prevent bone resorption but did promote bone formation, and helped mitigate the net bone loss associated with simulated microgravity.
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Affiliation(s)
- Scott M Smith
- Human Adaptation and Countermeasures Division, National Aeronautics and Space Administration Lyndon B. Johnson Space Center, Houston, TX 77058, USA.
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