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Di Filippo ES, Chiappalupi S, Falone S, Dolo V, Amicarelli F, Marchianò S, Carino A, Mascetti G, Valentini G, Piccirillo S, Balsamo M, Vukich M, Fiorucci S, Sorci G, Fulle S. The MyoGravity project to study real microgravity effects on human muscle precursor cells and tissue. NPJ Microgravity 2024; 10:92. [PMID: 39362881 PMCID: PMC11450100 DOI: 10.1038/s41526-024-00432-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 09/22/2024] [Indexed: 10/05/2024] Open
Abstract
Microgravity (µG) experienced during space flights promotes adaptation in several astronauts' organs and tissues, with skeletal muscles being the most affected. In response to reduced gravitational loading, muscles (especially, lower limb and antigravity muscles) undergo progressive mass loss and alteration in metabolism, myofiber size, and composition. Skeletal muscle precursor cells (MPCs), also known as satellite cells, are responsible for the growth and maintenance of muscle mass in adult life as well as for muscle regeneration following damage and may have a major role in µG-induced muscle wasting. Despite the great relevance for astronaut health, very few data are available about the effects of real µG on human muscles. Based on the MyoGravity project, this study aimed to analyze: (i) the cellular and transcriptional alterations induced by real µG in human MPCs (huMPCs) and (ii) the response of human skeletal muscle to normal gravitational loading after prolonged exposure to µG. We evaluated the transcriptomic changes induced by µG on board the International Space Station (ISS) in differentiating huMPCs isolated from Vastus lateralis muscle biopsies of a pre-flight astronaut and an age- and sex-matched volunteer, in comparison with the same cells cultured on the ground in standard gravity (1×g) conditions. We found that huMPCs differentiated under real µG conditions showed: (i) upregulation of genes related to cell adhesion, plasma membrane components, and ion transport; (ii) strong downregulation of genes related to the muscle contraction machinery and sarcomere organization; and (iii) downregulation of muscle-specific microRNAs (myomiRs). Moreover, we had the unique opportunity to analyze huMPCs and skeletal muscle tissue of the same astronaut before and 30 h after a long-duration space flight on board the ISS. Prolonged exposure to real µG strongly affected the biology and functionality of the astronaut's satellite cells, which showed a dramatic reduction of responsiveness to activating stimuli and proliferation rate, morphological changes, and almost inability to fuse into myotubes. RNA-Seq analysis of post- vs. pre-flight muscle tissue showed that genes involved in muscle structure and remodeling are promptly activated after landing following a long-duration space mission. Conversely, genes involved in the myelination process or synapse and neuromuscular junction organization appeared downregulated. Although we have investigated only one astronaut, these results point to a prompt readaptation of the skeletal muscle mechanical components to the normal gravitational loading, but the inability to rapidly recover the physiological muscle myelination/innervation pattern after landing from a long-duration space flight. Together with the persistent functional deficit observed in the astronaut's satellite cells after prolonged exposure to real µG, these results lead us to hypothesize that a condition of inefficient regeneration is likely to occur in the muscles of post-flight astronauts following damage.
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Affiliation(s)
- Ester Sara Di Filippo
- Department of Neuroscience Imaging and Clinical Sciences, University "G. d'Annunzio" Chieti-Pescara, 66100, Chieti, Italy
- Interuniversity Institute of Myology (IIM), 06132, Perugia, Italy
| | - Sara Chiappalupi
- Interuniversity Institute of Myology (IIM), 06132, Perugia, Italy
- Department Medicine and Surgery, University of Perugia, 06132, Perugia, Italy
- Consorzio Interuniversitario Biotecnologie (CIB), 34127, Trieste, Italy
| | - Stefano Falone
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Vincenza Dolo
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Fernanda Amicarelli
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Silvia Marchianò
- Department Medicine and Surgery, University of Perugia, 06132, Perugia, Italy
| | - Adriana Carino
- Department Medicine and Surgery, University of Perugia, 06132, Perugia, Italy
| | | | | | | | - Michele Balsamo
- Kayser Italia S.r.l, Via di Popogna, 501, 57128, Livorno, Italy
| | - Marco Vukich
- European Space Agency, Keplerlaan 1, NL-2200, AG, Noordwijk, The Netherlands
| | - Stefano Fiorucci
- Department Medicine and Surgery, University of Perugia, 06132, Perugia, Italy
| | - Guglielmo Sorci
- Interuniversity Institute of Myology (IIM), 06132, Perugia, Italy
- Department Medicine and Surgery, University of Perugia, 06132, Perugia, Italy
- Consorzio Interuniversitario Biotecnologie (CIB), 34127, Trieste, Italy
| | - Stefania Fulle
- Department of Neuroscience Imaging and Clinical Sciences, University "G. d'Annunzio" Chieti-Pescara, 66100, Chieti, Italy.
- Interuniversity Institute of Myology (IIM), 06132, Perugia, Italy.
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Han H, Jia H, Wang YF, Song JP. Cardiovascular adaptations and pathological changes induced by spaceflight: from cellular mechanisms to organ-level impacts. Mil Med Res 2024; 11:68. [PMID: 39334239 PMCID: PMC11429428 DOI: 10.1186/s40779-024-00570-3] [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: 03/04/2024] [Accepted: 09/01/2024] [Indexed: 09/30/2024] Open
Abstract
The advancement in extraterrestrial exploration has highlighted the crucial need for studying how the human cardiovascular system adapts to space conditions. Human development occurs under the influence of gravity, shielded from space radiation by Earth's magnetic field, and within an environment characterized by 24-hour day-night cycles resulting from Earth's rotation, thus deviating from these conditions necessitates adaptive responses for survival. With upcoming manned lunar and Martian missions approaching rapidly, it is essential to understand the impact of various stressors induced by outer-space environments on cardiovascular health. This comprehensive review integrates insights from both actual space missions and simulated experiments on Earth, to analyze how microgravity, space radiation, and disrupted circadian affect cardiovascular well-being. Prolonged exposure to microgravity induces myocardial atrophy and endothelial dysfunction, which may be exacerbated by space radiation. Mitochondrial dysfunction and oxidative stress emerge as key underlying mechanisms along with disturbances in ion channel perturbations, cytoskeletal damage, and myofibril changes. Disruptions in circadian rhythms caused by factors such as microgravity, light exposure, and irregular work schedules, could further exacerbate cardiovascular issues. However, current research tends to predominantly focus on disruptions in the core clock gene, overlooking the multifactorial nature of circadian rhythm disturbances in space. Future space missions should prioritize targeted prevention strategies and early detection methods for identifying cardiovascular risks, to preserve astronaut health and ensure mission success.
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Affiliation(s)
- Han Han
- Beijing Key Laboratory of Preclinical Research and Evaluation for Cardiovascular Implant Materials, Animal Experimental Centre, National Centre for Cardiovascular Disease; Department of Cardiac Surgery, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Hao Jia
- Beijing Key Laboratory of Preclinical Research and Evaluation for Cardiovascular Implant Materials, Animal Experimental Centre, National Centre for Cardiovascular Disease; Department of Cardiac Surgery, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Yi-Fan Wang
- Beijing Key Laboratory of Preclinical Research and Evaluation for Cardiovascular Implant Materials, Animal Experimental Centre, National Centre for Cardiovascular Disease; Department of Cardiac Surgery, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Jiang-Ping Song
- Beijing Key Laboratory of Preclinical Research and Evaluation for Cardiovascular Implant Materials, Animal Experimental Centre, National Centre for Cardiovascular Disease; Department of Cardiac Surgery, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China.
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Caddy HT, Fujino M, Vahabli E, Voigt V, Kelsey LJ, Dilley RJ, Carvalho LS, Takahashi S, Green DJ, Doyle BJ. Simulation of murine retinal hemodynamics in response to tail suspension. Comput Biol Med 2024; 182:109148. [PMID: 39298883 DOI: 10.1016/j.compbiomed.2024.109148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 09/03/2024] [Accepted: 09/08/2024] [Indexed: 09/22/2024]
Abstract
The etiology of spaceflight-associated neuro-ocular syndrome (SANS) remains unclear. Recent murine studies indicate there may be a link between the space environment and retinal endothelial dysfunction. Post-fixed control (N = 4) and 14-day tail-suspended (TS) (N = 4) mice eye samples were stained and imaged for the vessel plexus and co-located regions of endothelial cell death. A custom workflow combined whole-mounted and tear reconstructed three-dimensional (3D) spherical retinal plexus models with computational fluid dynamics (CFD) simulation that accounted for the Fåhræus-Lindqvist effect and boundary conditions that accommodated TS fluid pressure measurements and deeper capillary layer blood flow distribution. TS samples exhibited reduced surface area (4.6 ± 0.5 mm2 vs. 3.5 ± 0.3 mm2, P = 0.010) and shorter lengths between branches in small vessels (<10 μm, 69.5 ± 0.6 μm vs. 60.4 ± 1.1 μm, P < 0.001). Wall shear stress (WSS) and pressure were higher in TS mice compared to controls, particularly in smaller vessels (<10 μm, WSS: 6.57 ± 1.08 Pa vs. 4.72 ± 0.67 Pa, P = 0.034, Pressure: 72.04 ± 3.14 mmHg vs. 50.64 ± 6.74 mmHg, P = 0.004). Rates of retinal endothelial cell death were variable in TS mice compared to controls. WSS and pressure were generally higher in cell death regions, both within and between cohorts, but significance was variable and limited to small to medium-sized vessels (<20 μm). These findings suggest a link may exist between emulated microgravity and retinal endothelial dysfunction that may have implications for SANS development. Future work with increased sample sizes of larger species or spaceflight cohorts should be considered.
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Affiliation(s)
- Harrison T Caddy
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, Australia and the UWA Centre for Medical Research, The University of Western Australia, Perth, Australia; School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, Perth, Australia
| | - Mitsunori Fujino
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan; Ph.D. Program in Human Biology, School of Integrative and Global Majors, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Ebrahim Vahabli
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, Australia and the UWA Centre for Medical Research, The University of Western Australia, Perth, Australia; School of Engineering, The University of Western Australia, Perth, Australia; T3mPLATE, Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre and UWA Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Valentina Voigt
- Centre for Experimental Immunology, Lions Eye Institute, Nedlands, Australia
| | - Lachlan J Kelsey
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, Australia and the UWA Centre for Medical Research, The University of Western Australia, Perth, Australia; School of Engineering, The University of Western Australia, Perth, Australia
| | - Rodney J Dilley
- T3mPLATE, Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre and UWA Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Livia S Carvalho
- Retinal Genomics and Therapy Group, Centre for Ophthalmology and Visual Sciences (incorporating Lions Eye Institute), The University of Western Australia, Perth, Australia; Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Satoru Takahashi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan; Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Ibaraki, Japan; Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, Japan; International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan; Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Daniel J Green
- School of Human Sciences (Exercise and Sport Sciences), The University of Western Australia, Perth, Australia
| | - Barry J Doyle
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, Australia and the UWA Centre for Medical Research, The University of Western Australia, Perth, Australia; School of Engineering, The University of Western Australia, Perth, Australia.
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Clément G, Moudy SC, Macaulay TR, Mulder E, Wood SJ. Effects of intermittent seating upright, lower body negative pressure, and exercise on functional tasks performance after head-down tilt bed rest. Front Physiol 2024; 15:1442239. [PMID: 39308978 PMCID: PMC11412840 DOI: 10.3389/fphys.2024.1442239] [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: 06/01/2024] [Accepted: 08/20/2024] [Indexed: 09/25/2024] Open
Abstract
Introduction Bed rest can be used as a ground-based analog of the body unloading associated with spaceflight. In this study, we determined how strict head-down tilt bed rest affects subjects' performance of functional tests (sit-to-stand, tandem walk, walk-and-turn, dynamic posturography) that challenge astronauts' balance control systems immediately after they return from space. Methods Forty-seven participants were assessed before and a few hours after 30 days of 6° head down tilt bed rest at the DLR:envihab facility. During this bed rest study, called SANS-CM, the participants were divided into 4 groups that either a) were positioned in head-down tilt continuously throughout the 30 days; b) sat upright for 6 h a day; c) were exposed to lower body negative pressure (LBNP) for 6 h a day; or d) exercised for 60 min and then wore venous-occlusive cuffs for 6 h a day. Results Results showed that strict head-down tilt bed rest caused deficits in performance of functional tasks that were similar to those observed in astronauts after spaceflight. Seated upright posture mitigated these deficits, whereas exercise or LBNP and cuffs partly mitigated them. Discussion These data suggest that more direct, active sensorimotor-based countermeasures may be necessary to maintain preflight levels of functional performance after a long period of body unloading.
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Affiliation(s)
| | | | | | - Edwin Mulder
- DLR, Institute of Aerospace Medicine, Cologne, Germany
| | - Scott J. Wood
- NASA Johnson Space Center, Houston, TX, United States
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Li Y, Zhang X, Xu Z, Chu X, Hu Z, Ye Z, Li C, Wang Z, Zeng B, Pan J, Zhao Q, Zhou C, Lan Z, Kan G, He G, Xu X, Li W. Simulated weightlessness procedure, head-down bed rest has reversible effects on the metabolism of rhesus macaque. Mol Brain 2024; 17:65. [PMID: 39227961 PMCID: PMC11370317 DOI: 10.1186/s13041-024-01133-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Accepted: 08/07/2024] [Indexed: 09/05/2024] Open
Abstract
It is a consensus in the international manned space field that factors such as microgravity during the space flight can cause anxiety, depression and other important brain function abnormalities in astronauts. However, the neural mechanism at the molecular level is still unclear. Due to the limitations of research conditions, studies of biological changes in the primate brain have been comparatively few. We took advantage of -6° head-down bed rest (HDBR), one of the most implemented space analogues on the ground, to investigate the effects of simulated weightlessness on non-human primate brain metabolites. The Rhesus Macaque monkeys in the experiment were divided into three groups: the control group, the 42-day simulated weightlessness group with HDBR, and the recovery group, which had 28 days of free activity in the home cage after the HDBR. Liquid chromatography-mass spectrometry (LC-MS) was used to perform metabolomics analysis on specific brain areas of the monkeys under three experimental conditions. Our results show that simulated weightlessness can cause neurotransmitter imbalances, the amino acid and energy metabolism disorders, and hormone disturbances. But these metabolomics changes are reversible after recovery. Our study suggests that long-term brain damage in space flight might be reversible at the metabolic level. This lays a technical foundation for ensuring brain health and enhancing the brain function in future space studies.
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Affiliation(s)
- Yuting Li
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xu Zhang
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Zhen Xu
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xixia Chu
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhiqiang Hu
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhengyang Ye
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Caiqin Li
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhenbo Wang
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bin Zeng
- National Key Laboratory of Human Factors Engineering, Astronaut Research and Training Center, Beijing, 100094, China
| | - Jingyu Pan
- National Key Laboratory of Human Factors Engineering, Astronaut Research and Training Center, Beijing, 100094, China
| | - Qian Zhao
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chengbin Zhou
- Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Zhaohui Lan
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Guanghan Kan
- National Key Laboratory of Human Factors Engineering, Astronaut Research and Training Center, Beijing, 100094, China
| | - Guang He
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaodan Xu
- National Key Laboratory of Human Factors Engineering, Astronaut Research and Training Center, Beijing, 100094, China.
| | - Weidong Li
- Bio-X Institutes (Key Laboratory for the Genetics of Development and Neuropsychiatric Disorders, Brain Health and Brain Technology Research Center in Global Institute of Future Technology, Institute of Psychology and Behavioral Science, Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200240, China.
- WLA Laboratories, World Laureates Association, Shanghai, 201203, China.
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Iftime A, Tofolean IT, Pintilie V, Călinescu O, Busnatu S, Papacocea IR. Differential Functional Changes in Visual Performance during Acute Exposure to Microgravity Analogue and Their Potential Links with Spaceflight-Associated Neuro-Ocular Syndrome. Diagnostics (Basel) 2024; 14:1918. [PMID: 39272703 PMCID: PMC11394298 DOI: 10.3390/diagnostics14171918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 08/23/2024] [Accepted: 08/28/2024] [Indexed: 09/15/2024] Open
Abstract
BACKGROUND Spaceflight-Associated Neuro-Ocular Syndrome (SANS) is a complex pathology threatening the health of astronauts, with incompletely understood causes and no current specific functional diagnostic or screening test. We investigated the use of the differential performance of the visual system (central vs. perimacular visual function) as a candidate marker of SANS-related pathology in a ground-based microgravity analogue. METHODS We used a simple reaction time (SRT) task to visual stimuli, presented in the central and perimacular field of view, as a measure of the overall performance of the visual function, during acute settings (first 10 min) of vertical, bed rest (BR), -6°, and -15° head-down tilt (HDT) presentations in healthy participants (n = 8). We built dose-response models linking the gravitational component to SRT distribution parameters in the central vs. perimacular areas. RESULTS Acute exposure to microgravity induces detectable changes between SRT distributions in the perimacular vs. central retina (increased mean, standard deviation, and tau component of the ex-Gaussian function) in HDT compared with vertical presentation. CONCLUSIONS Functional testing of the perimacular retina might be beneficial for the earlier detection of SANS-related ailments in addition to regular testing of the central vision. Future diagnostic tests should consider the investigation of the extra-macular areas, particularly towards the optic disc.
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Affiliation(s)
- Adrian Iftime
- Biophysics Department, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Ioana Teodora Tofolean
- Ophthalmology Department, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Clinical Emergency Eye Hospital, 010464 Bucharest, Romania
| | - Victor Pintilie
- Biophysics Department, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Octavian Călinescu
- Biophysics Department, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Stefan Busnatu
- Department of Cardiology, University of Medicine and Pharmacy "Carol Davila", Emergency Hospital "Bagdasar-Arseni", 050474 Bucharest, Romania
- Center for Innovation and eHealth, Carol Davila University of Medicine and Pharmacy, 010451 Bucharest, Romania
| | - Ioana Raluca Papacocea
- Center for Innovation and eHealth, Carol Davila University of Medicine and Pharmacy, 010451 Bucharest, Romania
- Physiology III Department, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
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Alessandro C, Sarabadani Tafreshi A, Riener R. Cardiovascular responses to leg-press exercises during head-down tilt. Front Sports Act Living 2024; 6:1396391. [PMID: 39290333 PMCID: PMC11406980 DOI: 10.3389/fspor.2024.1396391] [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: 03/05/2024] [Accepted: 08/12/2024] [Indexed: 09/19/2024] Open
Abstract
Introduction Physical exercise and gravitational load affect the activity of the cardiovascular system. How these factors interact with one another is still poorly understood. Here we investigate how the cardiovascular system responds to leg-press exercise during head-down tilt, a posture that reduces orthostatic stress, limits gravitational pooling, and increases central blood volume. Methods Seventeen healthy participants performed leg-press exercise during head-down tilt at different combinations of resistive force, contraction frequency, and exercise duration (30 and 60 s), leading to different exercise power. Systolic (sBP), diastolic (dBP), mean arterial pressure (MAP), pulse pressure (PP) and heart rate (HR) were measured continuously. Cardiovascular responses were evaluated by comparing the values of these signals during exercise recovery to baseline. Mixed models were used to evaluate the effect of exercise power and of individual exercise parameter on the cardiovascular responses. Results Immediately after the exercise, we observed a clear undershoot in sBP (Δ = -7.78 ± 1.19 mmHg), dBP (Δ = -10.37 ± 0.84 mmHg), and MAP (Δ = -8.85 ± 0.85 mmHg), an overshoot in PP (Δ = 7.93 ± 1.13 mmHg), and elevated values of HR (Δ = 33.5 ± 0.94 bpm) compared to baseline (p < 0.0001). However, all parameters returned to similar baseline values 2 min following the exercise (p > 0.05). The responses of dBP, MAP and HR were significantly modulated by exercise power (correlation coefficients: rdBP = -0.34, rMAP = -0.25, rHR = 0.52, p < 0.001). All signals' responses were modulated by contraction frequency (p < 0.05), increasing the undershoot in sBP (Δ = -1.87 ± 0.98 mmHg), dBP (Δ = -4.85 ± 1.01 and Δ = -3.45 ± 0.98 mmHg for low and high resistive force respectively) and MAP (Δ = -3.31 ± 0.75 mmHg), and increasing the overshoot in PP (Δ = 2.57 ± 1.06 mmHg) as well as the value of HR (Δ = 16.8 ± 2.04 and Δ = 10.8 ± 2.01 bpm for low and high resistive force respectively). Resistive force affected only dBP (Δ = -4.96 ± 1.41 mmHg, p < 0.0001), MAP (Δ = -2.97 ± 1.07 mmHg, p < 0.05) and HR (Δ = 6.81 ± 2.81 bpm, p < 0.0001; Δ = 15.72 ± 2.86 bpm, p < 0.0001; Δ = 15.72 ± 2.86 bpm, p < 0.05, depending on the values of resistive force and contraction frequency), and exercise duration affected only HR (Δ = 9.64 ± 2.01 bpm, p < 0.0001). Conclusion Leg exercises caused only immediate cardiovascular responses, potentially due to facilitated venous return by the head-down tilt position. The modulation of dBP, MAP and HR responses by exercise power and that of all signals by contraction frequency may help optimizing exercise prescription in conditions of limited orthostatic stress.
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Affiliation(s)
- Cristiano Alessandro
- School of Medicine and Surgery, Sport and Exercise Medicine, University of Milano-Bicocca, Milan, Italy
- Sensory-Motor Systems Lab, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zurich, Zurich, Switzerland
| | - Amirehsan Sarabadani Tafreshi
- Sensory-Motor Systems Lab, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zurich, Zurich, Switzerland
| | - Robert Riener
- Sensory-Motor Systems Lab, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zurich, Zurich, Switzerland
- Spinal Cord Injury Center, Medical Faculty, University of Zurich, Zurich, Switzerland
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Swain P, Caplan N, Hughes L. Blood flow restriction: The acute effects of body tilting and reduced gravity analogues on limb occlusion pressure. Exp Physiol 2024. [PMID: 39153209 DOI: 10.1113/ep091874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 07/30/2024] [Indexed: 08/19/2024]
Abstract
Blood flow restriction (BFR) has been identified as a potential countermeasure to mitigate physiological deconditioning during spaceflight. Guidelines recommend that tourniquet pressure be prescribed relative to limb occlusion pressure (LOP); however, it is unclear whether body tilting or reduced gravity analogues influence LOP. We examined LOP at the leg and arm during supine bedrest and bodyweight suspension (BWS) at 6° head-down tilt (HDT), horizontal (0°), and 9.5° head-up tilt (HUT) positions. Twenty-seven adults (age, 26 ± 5 years; height, 1.75 ± 0.08 m; body mass, 73 ± 12 kg) completed all tilts during bedrest. A subgroup (n = 15) additionally completed the tilts during BWS. In each position, LOP was measured twice in the leg and arm using the Delfi Personalized Tourniquet System after 5 min of rest and again after a further 5 min. The LOP at the leg increased significantly from 6° HDT to 9.5° HUT in bedrest and BWS by 9-15 mmHg (Cohen's d = 0.7-1.0). Leg LOP was significantly higher during BWS at horizontal and 9.5° HUT postures relative to the same angles during bedrest by 8 mmHg (Cohen's d = 0.6). Arm LOP remained unchanged between body tilts and analogues. Intraclass correlation coefficients for LOP measurements taken after an initial and subsequent 5 min rest period in all conditions ranged between 0.91-0.95 (leg) and 0.83-0.96 (arm). It is advised that LOP be measured before the application of a vascular occlusion in the same body tilt/setting to which it is applied to minimize discrepancies between the actual and prescribed tourniquet pressure.
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Affiliation(s)
- Patrick Swain
- Aerospace Medicine and Rehabilitation Laboratory, Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Nick Caplan
- Aerospace Medicine and Rehabilitation Laboratory, Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Luke Hughes
- Aerospace Medicine and Rehabilitation Laboratory, Department of Sport, Exercise and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
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Ibrahim Z, Khan NA, Siddiqui R, Qaisar R, Marzook H, Soares NC, Elmoselhi AB. Gut matters in microgravity: potential link of gut microbiota and its metabolites to cardiovascular and musculoskeletal well-being. Nutr Metab (Lond) 2024; 21:66. [PMID: 39123239 PMCID: PMC11316329 DOI: 10.1186/s12986-024-00836-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 07/27/2024] [Indexed: 08/12/2024] Open
Abstract
The gut microbiota and its secreted metabolites play a significant role in cardiovascular and musculoskeletal health and diseases. The dysregulation of the intestinal microbiota poses a significant threat to cardiovascular and skeletal muscle well-being. Nonetheless, the precise molecular mechanisms underlying these changes remain unclear. Furthermore, microgravity presents several challenges to cardiovascular and musculoskeletal health compromising muscle strength, endothelial dysfunction, and metabolic changes. The purpose of this review is to critically examine the role of gut microbiota metabolites on cardiovascular and skeletal muscle functions and dysfunctions. It also explores the molecular mechanisms that drive microgravity-induced deconditioning in both cardiovascular and skeletal muscle. Key findings in this review highlight that several alterations in gut microbiota and secreted metabolites in microgravity mirror characteristics seen in cardiovascular and skeletal muscle diseases. Those alterations include increased levels of Firmicutes/Bacteroidetes (F/B) ratio, elevated lipopolysaccharide levels (LPS), increased in para-cresol (p-cresol) and secondary metabolites, along with reduction in bile acids and Akkermansia muciniphila bacteria. Highlighting the potential, modulating gut microbiota in microgravity conditions could play a significant role in mitigating cardiovascular and skeletal muscle diseases not only during space flight but also in prolonged bed rest scenarios here on Earth.
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Affiliation(s)
- Zeinab Ibrahim
- Research Institute of Medical & Health Sciences, University of Sharjah, Sharjah, 27272, UAE
- Basic Medical Sciences Department, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Naveed A Khan
- Microbiota Research Center, Istinye University, Istanbul, 34010, Turkey
| | - Ruqaiyyah Siddiqui
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh, EH14 4AS,, UK
- Microbiota Research Center, Istinye University, Istanbul, 34010, Turkey
| | - Rizwan Qaisar
- Research Institute of Medical & Health Sciences, University of Sharjah, Sharjah, 27272, UAE
- Basic Medical Sciences Department, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Hezlin Marzook
- Research Institute of Medical & Health Sciences, University of Sharjah, Sharjah, 27272, UAE
| | - Nelson C Soares
- Center for Applied and Translational Genomics (CATG), Mohammed Bin Rashid university of Medicine and Health Sciences, Dubai, 0000, United Arab Emirates
- Laboratory of Proteomics, Department of Human Genetics, National Institute of Health Doutor Ricardo Jorge (INSA), Av Padre Cruz, Lisbon, 1649-016, Portugal
| | - Adel B Elmoselhi
- Research Institute of Medical & Health Sciences, University of Sharjah, Sharjah, 27272, UAE.
- Basic Medical Sciences Department, College of Medicine, University of Sharjah, Sharjah, 27272, United Arab Emirates.
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10
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Mastrandrea CJ, Hedge ET, Hughson RL. The Detrimental Effects of Bedrest: Premature Cardiovascular Aging and Dysfunction. Can J Cardiol 2024; 40:1468-1482. [PMID: 38759726 DOI: 10.1016/j.cjca.2024.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/19/2024] Open
Abstract
Bedrest as an experimental paradigm or as an in-patient stay for medical reasons has negative consequences for cardiovascular health. The effects of severe inactivity parallel many of the changes experienced with natural aging but over a much shorter duration. Cardiac function is reduced, arteries stiffen, neural reflex responses are impaired, and metabolic and oxidative stress responses impose burden on the heart and vascular systems. The effect of these changes is revealed in studies of integrative function. Aerobic fitness progressively deteriorates with bedrest and tolerance of upright posture is rapidly impaired. In this review we consider the similarities of aging and bedrest-induced cardiovascular deconditioning. We concur with many recent clinical recommendations that early and regular mobility with upright posture will reduce likelihood of hospital-associated disability related to bedrest.
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Affiliation(s)
- Carmelo J Mastrandrea
- Schlegel-UW Research Institute for Aging, Waterloo, Ontario, Canada; Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Eric T Hedge
- Schlegel-UW Research Institute for Aging, Waterloo, Ontario, Canada; Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Richard L Hughson
- Schlegel-UW Research Institute for Aging, Waterloo, Ontario, Canada.
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11
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Mendes Zambetta R, Signini ÉDF, Ocamoto GN, Catai AM, Uliam NR, Santarnecchi E, Russo TL. Effects of weightlessness on the cardiovascular system: a systematic review and meta-analysis. Front Physiol 2024; 15:1438089. [PMID: 39129756 PMCID: PMC11310543 DOI: 10.3389/fphys.2024.1438089] [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: 05/25/2024] [Accepted: 07/02/2024] [Indexed: 08/13/2024] Open
Abstract
Background: The microgravity environment has a direct impact on the cardiovascular system due to the fluid shift and weightlessness that results in cardiac dysfunction, vascular remodeling, and altered Cardiovascular autonomic modulation (CAM), deconditioning and poor performance on space activities, ultimately endangering the health of astronauts. Objective: This study aimed to identify the acute and chronic effects of microgravity and Earth analogues on cardiovascular anatomy and function and CAM. Methods: CINAHL, Cochrane Library, Scopus, Science Direct, PubMed, and Web of Science databases were searched. Outcomes were grouped into cardiovascular anatomic, functional, and autonomic alterations, and vascular remodeling. Studies were categorized as Spaceflight (SF), Chronic Simulation (CS), or Acute Simulation (AS) based on the weightlessness conditions. Meta-analysis was performed for the most frequent outcomes. Weightlessness and control groups were compared. Results: 62 articles were included with a total of 963 participants involved. The meta-analysis showed that heart rate increased in SF [Mean difference (MD) = 3.44; p = 0.01] and in CS (MD = 4.98; p < 0.0001), whereas cardiac output and stroke volume decreased in CS (MD = -0.49; p = 0.03; and MD = -12.95; p < 0.0001, respectively), and systolic arterial pressure decreased in AS (MD = -5.20; p = 0.03). According to the qualitative synthesis, jugular vein cross-sectional area (CSA) and volume were greater in all conditions, and SF had increased carotid artery CSA. Heart rate variability and baroreflex sensitivity, in general, decreased in SF and CS, whereas both increased in AS. Conclusion: This review indicates that weightlessness impairs the health of astronauts during and after spaceflight, similarly to the effects of aging and immobility, potentially increasing the risk of cardiovascular diseases. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42020215515.
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Affiliation(s)
| | - Étore De Favari Signini
- Physical Therapy Department, Federal University of São Carlos, UFSCar, São Carlos, SP, Brazil
| | - Gabriela Nagai Ocamoto
- Physical Therapy Department, Federal University of São Carlos, UFSCar, São Carlos, SP, Brazil
- Brain4care Inc., São Carlos, SP, Brazil
| | - Aparecida Maria Catai
- Physical Therapy Department, Federal University of São Carlos, UFSCar, São Carlos, SP, Brazil
| | - Nicoly Ribeiro Uliam
- Physical Therapy Department, Federal University of São Carlos, UFSCar, São Carlos, SP, Brazil
| | | | - Thiago Luiz Russo
- Physical Therapy Department, Federal University of São Carlos, UFSCar, São Carlos, SP, Brazil
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12
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Reddy A, Pan Y, Finberg A, Dong H, Kesser B. Flow Analysis of Central Venous Outflow Tract: A New Approach to Understanding Pulse-Synchronous Tinnitus. Otolaryngol Head Neck Surg 2024. [PMID: 38984878 DOI: 10.1002/ohn.891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 06/02/2024] [Accepted: 06/05/2024] [Indexed: 07/11/2024]
Abstract
OBJECTIVE Pulse-synchronous tinnitus (PST) has been linked to multiple anatomical variants of the central venous outflow tract (CVOT) including sigmoid sinus (SS) dehiscence and diverticulum. This study investigates flow turbulence, pressure, and wall shear stress along the CVOT and proposes a mechanism that results in SS dehiscence and PST. STUDY DESIGN Case series. SETTING Tertiary Academic Center. METHODS Venous models were reconstructed from computed tomography scans of 3 patients with unilateral PST. Two models for each patient are obtained: a symptomatic and contralateral asymptomatic side. A turbulent model-enabled commercial flow solver was used to simulate the pulsatile blood flow over the cardiac cycle through the models. Fluid flow through the transverse and SS junction was analyzed to observe the velocity, pressure, turbulent kinetic energy (TKE), and shear stress over a simulated cardiac cycle. RESULTS Fluid flow on the symptomatic side showed increased vorticity in the presence of an SS diverticulum. Higher TKE with periodicity following the cardiac cycle was observed on the symptomatic side, and a sharp increase was observed if SS diverticulum was present. Shear stress was highest near the narrowest segments of the vessel. Pressure was observed to be lower on the symptomatic side at the transverse-SS junction for all 3 patients. CONCLUSION Computational fluid dynamics modeling of blood flow through the CVOT in PST suggests that low pressure may be the cause of dehiscence, and tinnitus may result from periodic increases in TKE.
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Affiliation(s)
- Adithya Reddy
- Department of Otolaryngology-Head and Neck Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Yu Pan
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Ariel Finberg
- Department of Otolaryngology-Head and Neck Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Haibo Dong
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Bradley Kesser
- Department of Otolaryngology-Head and Neck Surgery, University of Virginia, Charlottesville, Virginia, USA
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13
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Tölgyesi B, Altbäcker A, Barkaszi I, Stuckenschneider T, Braunsmann L, Takács E, Ehmann B, Balázs L, Abeln V. Effect of artificial gravity on neurocognitive performance during head-down tilt bedrest. NPJ Microgravity 2024; 10:59. [PMID: 38839787 PMCID: PMC11153507 DOI: 10.1038/s41526-024-00405-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 05/16/2024] [Indexed: 06/07/2024] Open
Abstract
This study evaluated the acute and chronic effects of intermittent and continuous Artificial Gravity (AG) on cognitive performance during 60 days of Head-down tilt bedrest (HDTBR), a well-established ground-based spaceflight analogue method. Participants were randomly assigned to three groups: intermittent AG, continuous AG, and HDTBR control group without AG exposure. Task performance and electrophysiological measures of attention and working memory were investigated during Simple and Complex tasks in the Visual and the Auditory modality. Compared to baseline, faster reaction time and better accuracy was present during HDTBR regarding the Complex tasks, however, the practice effect was diminished in the three HDTBR groups compared to an ambulatory control group. Brain potentials showed a modality-specific decrease, as P3a was decreased only in the Auditory, while P3b decreased in the Visual modality. No evidence for acute or chronic AG-related cognitive impairments during HDTBR was found.
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Affiliation(s)
- Borbála Tölgyesi
- Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
- Interaction and Immersion Hub, Innovation Center, Moholy-Nagy University of Art and Design, Budapest, Hungary
| | - Anna Altbäcker
- Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary.
| | - Irén Barkaszi
- Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
| | - Tim Stuckenschneider
- Institute of Movement and Neurosciences, Centre for Health and Integrative Physiology in Space (CHIPS), German Sport University Cologne, Cologne, Germany
- Geriatric Medicine, Department for Health, Services Research, School of Medicine and Health Sciences, Carl von Ossietzky University, Oldenburg, Germany
| | - Leonard Braunsmann
- Institute of Movement and Neurosciences, Centre for Health and Integrative Physiology in Space (CHIPS), German Sport University Cologne, Cologne, Germany
| | - Endre Takács
- Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
| | - Bea Ehmann
- Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
| | - László Balázs
- Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
| | - Vera Abeln
- Institute of Movement and Neurosciences, Centre for Health and Integrative Physiology in Space (CHIPS), German Sport University Cologne, Cologne, Germany
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14
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Murgia M, Rittweger J, Reggiani C, Bottinelli R, Mann M, Schiaffino S, Narici MV. Spaceflight on the ISS changed the skeletal muscle proteome of two astronauts. NPJ Microgravity 2024; 10:60. [PMID: 38839773 PMCID: PMC11153545 DOI: 10.1038/s41526-024-00406-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/22/2024] [Indexed: 06/07/2024] Open
Abstract
Skeletal muscle undergoes atrophy and loss of force during long space missions, when astronauts are persistently exposed to altered gravity and increased ionizing radiation. We previously carried out mass spectrometry-based proteomics from skeletal muscle biopsies of two astronauts, taken before and after a mission on the International Space Station. The experiments were part of an effort to find similarities between spaceflight and bed rest, a ground-based model of unloading, focused on proteins located at the costameres. We here extend the data analysis of the astronaut dataset and show compartment-resolved changes in the mitochondrial proteome, remodeling of the extracellular matrix and of the antioxidant response. The astronauts differed in their level of onboard physical exercise, which correlated with their respective preservation of muscle mass and force at landing in previous analyses. We show that the mitochondrial proteome downregulation during spaceflight, particularly the inner membrane and matrix, was dramatic for both astronauts. The expression of autophagy regulators and reactive oxygen species scavengers, however, showed partially opposite expression trends in the two subjects, possibly correlating with their level of onboard exercise. As mitochondria are primarily affected in many different tissues during spaceflight, we hypothesize that reactive oxygen species (ROS) rather than mechanical unloading per se could be the primary cause of skeletal muscle mitochondrial damage in space. Onboard physical exercise might have a strong direct effect on the prevention of muscle atrophy through mechanotransduction and a subsidiary effect on mitochondrial quality control, possibly through upregulation of autophagy and anti-oxidant responses.
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Affiliation(s)
- Marta Murgia
- Department of Biomedical Sciences, University of Padova, 35131, Padua, Italy.
- Max-Planck-Institute of Biochemistry, 82152, Martinsried, Germany.
| | - Jörn Rittweger
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
- Department of Pediatrics and Adolescent Medicine, University Hospital Cologne, Cologne, Germany
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, 35131, Padua, Italy
- Science and Research Center Koper, Institute for Kinesiology Research, 6000, Koper, Slovenia
| | - Roberto Bottinelli
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- IRCCS Policlinico San Matteo Foundation, Pavia, Italy
| | - Matthias Mann
- Department of Biomedical Sciences, University of Padova, 35131, Padua, Italy
- NNF Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Marco V Narici
- Department of Biomedical Sciences, University of Padova, 35131, Padua, Italy
- Science and Research Center Koper, Institute for Kinesiology Research, 6000, Koper, Slovenia
- CIR-MYO Myology Center, 35121, Padua, Italy
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15
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Semenov YS, Melnikov IS, Luzhnov PV, Dyachenko AI. Oscillations of Hemodynamic Parameters Induced by Negative Pressure Breathing in Healthy Humans. Aerosp Med Hum Perform 2024; 95:297-304. [PMID: 38790119 DOI: 10.3357/amhp.6419.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
INTRODUCTION: Negative pressure breathing is breathing with decreased pressure in the respiratory tract without lowering pressure acting on the torso. We lowered air pressure only during inspiration (NPBin). NPBin, used to increase venous return to the heart, is considered a countermeasure against redistribution of body fluids toward the head during spaceflight. We studied NPBin effects on circulation in healthy humans with an emphasis on NPBin-induced oscillations of hemodynamic parameters synchronous with breathing. We propose an approach to analyze the oscillations based on coherent averaging.METHODS: Eight men ages 24-42 yr participated in the NPBin and control series. During the series, to reproduce fluids shift observed under microgravity, subjects were supine and head down (-8°). Duration of NPBin was 20 min, rarefaction -20 cm H₂O. Hemodynamic parameters were measured by Finometer. Electrical impedance measurements were used to estimate changes in blood filling of cerebral vessels.RESULTS: Mean values of hemodynamic parameters virtually did not change under NPBin, but NPBin induced oscillations of the parameters synchronous with respiration. Peak-to-peak amplitude under NPBin were: mean arterial pressure, 4 ± 1 (mmHg); stroke volume, 7 ± 3 (mL); and heart rate, 4 ± 1 (bpm). Electrical impedance of the head increased during inspiration. The increase under NPBin was three times greater than under normal breathing.DISCUSSION: Analysis of oscillations gives more information than analysis of mean values. NPBin induces short-term decrease in left ventricle stroke volume and arterial blood pressure during each inspiration; the decrease is compensated by increase after inspiration. NPBin facilitates redistribution of body fluids away from the head.Semenov YS, Melnikov IS, Luzhnov PV, Dyachenko AI. Oscillations of hemodynamic parameters induced by negative pressure breathing in healthy humans. Aerosp Med Hum Perform. 2024; 95(6):297-304.
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16
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Mackenzie SW, Smith CP, Tremblay MF, Day BL, Reynolds RF. Bed rest impairs the vestibular control of balance. J Physiol 2024; 602:2985-2998. [PMID: 38766932 DOI: 10.1113/jp285834] [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: 10/31/2023] [Accepted: 04/18/2024] [Indexed: 05/22/2024] Open
Abstract
Prolonged bed rest impairs standing balance but the underlying mechanisms are uncertain. Previous research suggests strength loss is not the cause, leaving impaired sensorimotor control as an alternative. Here we examine vestibular control of posture in 18 male volunteers before and after 60 days of bed rest. Stochastic vestibular stimulation (SVS) was used to evoke sway responses before, 1 and 6 days after bed rest under different head yaw orientations. The directional accuracy and precision of these responses were calculated from ground reaction force vectors. Bed rest caused up to 63% increases in spontaneous standing sway and 31% reductions in leg strength, changes which were uncorrelated. The increase in sway was exacerbated when the eyes were closed. Mean directions of SVS-evoked sway responses were unaffected, being directed towards the anodal ear and rotating in line with head orientation in the same way before and after bed rest. However, individual trial analysis revealed 25%-30% increases in directional variability, which were significantly correlated with the increase in spontaneous sway (r = 0.48-0.71; P ≤ 0.044) and were still elevated on day 6 post-bed rest. This reveals that individual sway responses may be inappropriately oriented, a finding masked by the averaging process. Our results confirm that impaired balance following prolonged bedrest is not related to loss of strength. Rather, they demonstrate that the sensorimotor transformation process which converts vestibular feedback into appropriately directed balance responses is impaired. KEY POINTS: Prolonged inactivity impairs balance but previous research suggests this is not caused by loss of strength. Here we investigated vestibular control of balance before and after 60 days of bed rest using electrical vestibular stimulation (EVS) to evoke sway responses. Spontaneous sway significantly increased and muscle strength reduced following bed rest, but, in keeping with previous research, these two effects were not correlated. While the overall accuracy of EVS-evoked sway responses was unaffected, their directional variability significantly increased following bed rest, and this was correlated with the increases in spontaneous sway. We have shown that the ability to transform head-centred vestibular feedback into an appropriately directed body sway response is negatively affected by prolonged inactivity; this may contribute to the impaired balance commonly observed following bed rest.
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Affiliation(s)
- Stuart W Mackenzie
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Craig P Smith
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Malcom F Tremblay
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
| | - Brian L Day
- Department of Clinical and Movement Neurosciences, University College London, London, UK
| | - Raymond F Reynolds
- School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham, Birmingham, UK
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17
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Vora PM, Prabhu S. Exploring the influence of microgravity on chemotherapeutic drug response in cancer: Unveiling new perspectives. J Cell Mol Med 2024; 28:e18347. [PMID: 38693857 PMCID: PMC11063729 DOI: 10.1111/jcmm.18347] [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: 10/13/2023] [Revised: 03/30/2024] [Accepted: 04/08/2024] [Indexed: 05/03/2024] Open
Abstract
Microgravity, an altered gravity condition prevailing in space, has been reported to have a profound impact on human health. Researchers are very keen to comprehensively investigate the impact of microgravity and its intricate involvement in inducing physiological changes. Evidenced transformations were observed in the internal architecture including cytoskeletal organization and cell membrane morphology. These alterations can significantly influence cellular function, signalling pathways and overall cellular behaviour. Further, microgravity has been reported to alter in the expression profile of genes and metabolic pathways related to cellular processes, signalling cascades and structural proteins in cancer cells contributing to the overall changes in the cellular architecture. To investigate the effect of microgravity on cellular and molecular levels numerous ground-based simulation systems employing both in vitro and in vivo models are used. Recently, researchers have explored the possibility of leveraging microgravity to potentially modulate cancer cells against chemotherapy. These findings hold promise for both understanding fundamental processes and could potentially lead to the development of more effective, personalized and innovative approaches in therapeutic advancements against cancer.
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Affiliation(s)
- Preksha Manish Vora
- Department of Cell and Molecular Biology, Manipal School of Life SciencesManipal Academy of Higher EducationManipalIndia
| | - Sudharshan Prabhu
- Department of Cell and Molecular Biology, Manipal School of Life SciencesManipal Academy of Higher EducationManipalIndia
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18
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Fernandez‐Gonzalo R, Deane CS, Bailey DM. Experimental bed rest as a model to investigate mechanisms of, and countermeasures against, microgravity and disease-free inactivity. Exp Physiol 2024; 109:647-649. [PMID: 38477070 PMCID: PMC11061622 DOI: 10.1113/ep091795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024]
Affiliation(s)
- Rodrigo Fernandez‐Gonzalo
- Department of Laboratory Medicine, Division of Clinical PhysiologyKarolinska InstitutetStockholmSweden
- Unit of Clinical PhysiologyKarolinska University HospitalStockholmSweden
| | - Colleen S. Deane
- Human Development & Health, Faculty of MedicineUniversity of Southampton, Southampton General HospitalSouthamptonUK
| | - Damian Miles Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesPontypriddUK
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19
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Tays GD, Hupfeld KE, McGregor HR, Beltran NE, De Dios YE, Mulder E, Bloomberg JJ, Mulavara AP, Wood SJ, Seidler RD. Daily artificial gravity partially mitigates vestibular processing changes associated with head-down tilt bedrest. NPJ Microgravity 2024; 10:27. [PMID: 38472244 PMCID: PMC10933323 DOI: 10.1038/s41526-024-00367-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 02/15/2024] [Indexed: 03/14/2024] Open
Abstract
Microgravity alters vestibular signaling and reduces body loading, driving sensory reweighting. The unloading effects can be modelled using head-down tilt bedrest (HDT). Artificial gravity (AG) has been hypothesized to serve as an integrated countermeasure for the declines associated with HDT and spaceflight. Here, we examined the efficacy of 30 min of daily AG to counteract brain and behavior changes from 60 days of HDT. Two groups received 30 min of AG delivered via short-arm centrifuge daily (n = 8 per condition), either in one continuous bout, or in 6 bouts of 5 min. To improve statistical power, we combined these groups (AG; n = 16). Another group served as controls in HDT with no AG (CTRL; n = 8). We examined how HDT and AG affect vestibular processing by collecting fMRI scans during vestibular stimulation. We collected these data prior to, during, and post-HDT. We assessed brain activation initially in 12 regions of interest (ROIs) and then conducted an exploratory whole brain analysis. The AG group showed no changes in activation during vestibular stimulation in a cerebellar ROI, whereas the CTRL group showed decreased activation specific to HDT. Those that received AG and showed little pre- to post-HDT changes in left vestibular cortex activation had better post-HDT balance performance. Whole brain analyses identified increased pre- to during-HDT activation in CTRLs in the right precentral gyrus and right inferior frontal gyrus, whereas AG maintained pre-HDT activation levels. These results indicate that AG could mitigate activation changes in vestibular processing that is associated with better balance performance.
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Affiliation(s)
- G D Tays
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - K E Hupfeld
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - H R McGregor
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | | | | | - E Mulder
- German Aerospace Center (DLR), Cologne, Germany
| | | | | | - S J Wood
- NASA Johnson Space Center, Houston, TX, USA
| | - R D Seidler
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
- Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, USA.
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20
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Buescher FM, Schmitz MT, Frett T, Kramme J, de Boni L, Elmenhorst EM, Mulder E, Moestl S, Heusser K, Frings-Meuthen P, Jordan J, Rittweger J, Pesta D. Effects of 30 days bed rest and exercise countermeasures on PBMC bioenergetics. Acta Physiol (Oxf) 2024; 240:e14102. [PMID: 38294173 DOI: 10.1111/apha.14102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/27/2023] [Accepted: 01/08/2024] [Indexed: 02/01/2024]
Abstract
AIM Altered mitochondrial function across various tissues is a key determinant of spaceflight-induced physical deconditioning. In comparison to tissue biopsies, blood cell bioenergetics holds promise as a systemic and more readily accessible biomarker, which was evaluated during head-down tilt bed rest (HDTBR), an established ground-based analog for spaceflight-induced physiological changes in humans. More specifically, this study explored the effects of HDTBR and an exercise countermeasure on mitochondrial respiration in peripheral blood mononuclear cells (PBMCs). METHODS We subjected 24 healthy participants to a strict 30-day HDTBR protocol. The control group (n = 12) underwent HDTBR only, while the countermeasure group (n = 12) engaged in regular supine cycling exercise followed by veno-occlusive thigh cuffs post-exercise for 6 h. We assessed routine blood parameters 14 days before bed rest, the respiratory capacity of PBMCs via high-resolution respirometry, and citrate synthase activity 2 days before and at day 30 of bed rest. We confirmed PBMC composition by flow cytometry. RESULTS The change of the PBMC maximal oxidative phosphorylation capacity (OXPHOS) amounted to an 11% increase in the countermeasure group, while it decreased by 10% in the control group (p = 0.04). The limitation of OXPHOS increased in control only while other respiratory states were not affected by either intervention. Correlation analysis revealed positive associations between white blood cells, lymphocytes, and basophils with PBMC bioenergetics in both groups. CONCLUSION This study reveals that a regular exercise countermeasure has a positive impact on PBMC mitochondrial function, confirming the potential application of blood cell bioenergetics for human spaceflight.
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Affiliation(s)
- F-M Buescher
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - M T Schmitz
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
- Institute of Medical Biometry, Informatics and Epidemiology, Medical Faculty, University of Bonn, Bonn, Germany
| | - T Frett
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - J Kramme
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
- Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany
| | - L de Boni
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - E M Elmenhorst
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - E Mulder
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - S Moestl
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - K Heusser
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - P Frings-Meuthen
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - J Jordan
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
- Medical Faculty, University of Cologne, Cologne, Germany
| | - J Rittweger
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
| | - D Pesta
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
- Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany
- Medical Faculty, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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21
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Richmond SB, Seidler RD, Iliff JJ, Schwartz DL, Luther M, Silbert LC, Wood SJ, Bloomberg JJ, Mulder E, Lee JK, De Luca A, Piantino J. Dynamic changes in perivascular space morphology predict signs of spaceflight-associated neuro-ocular syndrome in bed rest. NPJ Microgravity 2024; 10:24. [PMID: 38429289 PMCID: PMC10907584 DOI: 10.1038/s41526-024-00368-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 02/15/2024] [Indexed: 03/03/2024] Open
Abstract
During long-duration spaceflight, astronauts experience headward fluid shifts and expansion of the cerebral perivascular spaces (PVS). A major limitation to our understanding of the changes in brain structure and physiology induced by spaceflight stems from the logistical difficulties of studying astronauts. The current study aimed to determine whether PVS changes also occur on Earth with the spaceflight analog head-down tilt bed rest (HDBR). We examined how the number and morphology of magnetic resonance imaging-visible PVS (MV-PVS) are affected by HDBR with and without elevated carbon dioxide (CO2). These environments mimic the headward fluid shifts, body unloading, and elevated CO2 observed aboard the International Space Station. Additionally, we sought to understand how changes in MV-PVS are associated with signs of Spaceflight Associated Neuro-ocular Syndrome (SANS), ocular structural alterations that can occur with spaceflight. Participants were separated into two bed rest campaigns: HDBR (60 days) and HDBR + CO2 (30 days with elevated ambient CO2). Both groups completed multiple magnetic resonance image acquisitions before, during, and post-bed rest. We found that at the group level, neither spaceflight analog affected MV-PVS quantity or morphology. However, when taking into account SANS status, persons exhibiting signs of SANS showed little or no MV-PVS changes, whereas their No-SANS counterparts showed MV-PVS morphological changes during the HDBR + CO2 campaign. These findings highlight spaceflight analogs as models for inducing changes in MV-PVS and implicate MV-PVS dynamic compliance as a mechanism underlying SANS. These findings may lead to countermeasures to mitigate health risks associated with human spaceflight.
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Affiliation(s)
- Sutton B Richmond
- Department of Applied Physiology and Kinesiology, University of Florida, 1864, Stadium Rd., Gainesville, FL, USA
| | - Rachael D Seidler
- Department of Applied Physiology and Kinesiology, University of Florida, 1864, Stadium Rd., Gainesville, FL, USA
- Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, USA
| | - Jeffrey J Iliff
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
- Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
- VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), VA Puget Sound Health Care System, Seattle, WA, USA
| | - Daniel L Schwartz
- Layton-NIA Oregon Aging and Alzheimer's Disease Research Center, Department of Neurology, Oregon Health & Science University, Portland, OR, USA
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, USA
| | - Madison Luther
- Department of Pediatrics, Division of Child Neurology, Doernbecher Children's Hospital, Oregon Health and Science University, Portland, OR, USA
| | - Lisa C Silbert
- Layton-NIA Oregon Aging and Alzheimer's Disease Research Center, Department of Neurology, Oregon Health & Science University, Portland, OR, USA
- Veteran's Affairs Portland Health Care System, Neurology, Portland, OR, USA
| | | | | | | | - Jessica K Lee
- Department of Applied Physiology and Kinesiology, University of Florida, 1864, Stadium Rd., Gainesville, FL, USA
- German Aerospace Center (DLR), Cologne, Germany
| | - Alberto De Luca
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Juan Piantino
- Department of Pediatrics, Division of Child Neurology, Doernbecher Children's Hospital, Oregon Health and Science University, Portland, OR, USA.
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22
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Neukart F. Towards sustainable horizons: A comprehensive blueprint for Mars colonization. Heliyon 2024; 10:e26180. [PMID: 38404830 PMCID: PMC10884476 DOI: 10.1016/j.heliyon.2024.e26180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 02/08/2024] [Accepted: 02/08/2024] [Indexed: 02/27/2024] Open
Abstract
This paper thoroughly explores the feasibility, challenges, and proposed solutions for establishing a sustainable human colony on Mars. We quantitatively and qualitatively analyze the Martian environment, highlighting key challenges such as radiation exposure, which astronauts could experience at minimum levels of 0.66 sieverts during a round trip, and the complications arising from Mars' thin atmosphere and extreme temperature variations. Technological advancements are examined, including developing Martian concrete, which utilizes sulfur as a binding agent, and innovative life support strategies like aeroponics and algae bioreactors. The human aspect of colonization is addressed, focusing on long-term space habitation's psychological and physiological impacts. We also present a cost-benefit analysis of in-situ resource utilization versus Earth-based supply missions, emphasizing economic viability with the potential reduction in launch costs through reusable rocket technology. A timeline for the colonization process is suggested, spanning preliminary unmanned missions for resource assessment, followed by short-term manned missions leading to sustainable settlements over several decades. The paper concludes with recommendations for future research, particularly in refining resource utilization techniques and advancing health and life support systems, to solidify the foundation for Mars colonization. This comprehensive assessment aims to guide researchers, policymakers, and stakeholders in planning and executing a strategic and informed approach to making Mars colonization a reality.
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Affiliation(s)
- Florian Neukart
- Leiden Institute of Advanced Computer Science, Snellius Gebouw, Niels Bohrweg 1, Leiden, 2333 CA, South Holland, Netherlands
- Terra Quantum AG, Kornhausstrasse 25, St. Gallen, 9000, St. Gallen, Switzerland
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23
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Tomsia M, Cieśla J, Śmieszek J, Florek S, Macionga A, Michalczyk K, Stygar D. Long-term space missions' effects on the human organism: what we do know and what requires further research. Front Physiol 2024; 15:1284644. [PMID: 38415007 PMCID: PMC10896920 DOI: 10.3389/fphys.2024.1284644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 01/22/2024] [Indexed: 02/29/2024] Open
Abstract
Space has always fascinated people. Many years have passed since the first spaceflight, and in addition to the enormous technological progress, the level of understanding of human physiology in space is also increasing. The presented paper aims to summarize the recent research findings on the influence of the space environment (microgravity, pressure differences, cosmic radiation, etc.) on the human body systems during short-term and long-term space missions. The review also presents the biggest challenges and problems that must be solved in order to extend safely the time of human stay in space. In the era of increasing engineering capabilities, plans to colonize other planets, and the growing interest in commercial space flights, the most topical issues of modern medicine seems to be understanding the effects of long-term stay in space, and finding solutions to minimize the harmful effects of the space environment on the human body.
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Affiliation(s)
- Marcin Tomsia
- Department of Forensic Medicine and Forensic Toxicology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Julia Cieśla
- School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Joanna Śmieszek
- School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Szymon Florek
- School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Agata Macionga
- School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Katarzyna Michalczyk
- Department of Physiology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
| | - Dominika Stygar
- Department of Physiology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Poland
- SLU University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden
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24
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Zhu D, Qiao P, Zhou Q, Sun H, Xin B, Wu B, Tang C. Effect of 15 days -6° head-down bed rest on microbial communities of supragingival plaque in young men. Front Microbiol 2024; 15:1331023. [PMID: 38328428 PMCID: PMC10849213 DOI: 10.3389/fmicb.2024.1331023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/04/2024] [Indexed: 02/09/2024] Open
Abstract
Introduction The microgravity environment astronauts experience during spaceflight can lead to an increased risk of oral diseases and possible changes in oral microecology. In this study, we aimed to assess changes in the microbial community of supragingival plaques to explore the effects of spaceflight microgravity environment on oral microecology. Methods Sixteen healthy male volunteers were recruited, and supragingival plaque samples were collected under -6° head-down bed rest (HDBR) at five-time points: day 1 before HDBR; days 5, 10, and 15 of HDBR; and day 6 of recovery. Bacterial genomic DNA was sequenced using gene sequencing technology with 16S ribosomal ribonucleic acid V3-V4 hypervariable region amplification and the obtained data were analyzed bioinformatically. Results Alpha diversity analysis showed a significant increase in species richness in supragingival plaque samples on day 15 of HDBR compared with that at pre-HDBR. Beta diversity analysis revealed that the community composition differed among the groups. Species distribution showed that, compared with those at pre-HDBR, the relative abundances of Corynebacterium and Aggregatibacter increased significantly during HDBR, while those of Veillonella, Streptococcus, and Lautropia decreased significantly. Moreover, compared with those at pre-HDBR, the relative abundance of Leptotrichia increased significantly on day 6 of recovery, whereas the relative abundances of Porphyromonas and Streptococcus decreased significantly. Network analysis showed that the interaction relationship between the dominant genera became simpler during HDBR, and the positive and negative correlations between them showed dynamic changes. Phylogenetic investigation of communities by reconstruction of unobserved states analysis showed that the amino acid metabolism function of plaque microorganisms was more enriched during HDBR. Discussion In summary, in a 15-day simulated microgravity environment, the diversity, species distribution, interaction relationship, and metabolic function of the supragingival plaque microbial community changed, which suggests that microgravity may affect the oral microecosystem by changing the balance of supragingival plaque microbial communities and further leading to the occurrence and development of oral diseases.
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Affiliation(s)
- Di Zhu
- 306th Clinical College of PLA, The Fifth Clinical College, Anhui Medical University, Beijing, China
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, China
| | - Pengyan Qiao
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, China
| | - Qian Zhou
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, China
| | - Hui Sun
- 306th Clinical College of PLA, The Fifth Clinical College, Anhui Medical University, Beijing, China
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, China
| | - Bingmu Xin
- Engineering Research Center of Human Circadian Rhythm and Sleep, Space Science and Technology Institute, Shenzhen, China
| | - Bin Wu
- China Astronaut Research and Training Center, Beijing, China
| | - Chuhua Tang
- 306th Clinical College of PLA, The Fifth Clinical College, Anhui Medical University, Beijing, China
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, China
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25
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Sayed RKA, Hibbert JE, Jorgenson KW, Hornberger TA. The Structural Adaptations That Mediate Disuse-Induced Atrophy of Skeletal Muscle. Cells 2023; 12:2811. [PMID: 38132132 PMCID: PMC10741885 DOI: 10.3390/cells12242811] [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: 11/11/2023] [Revised: 12/07/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023] Open
Abstract
The maintenance of skeletal muscle mass plays a fundamental role in health and issues associated with quality of life. Mechanical signals are one of the most potent regulators of muscle mass, with a decrease in mechanical loading leading to a decrease in muscle mass. This concept has been supported by a plethora of human- and animal-based studies over the past 100 years and has resulted in the commonly used term of 'disuse atrophy'. These same studies have also provided a great deal of insight into the structural adaptations that mediate disuse-induced atrophy. For instance, disuse results in radial atrophy of fascicles, and this is driven, at least in part, by radial atrophy of the muscle fibers. However, the ultrastructural adaptations that mediate these changes remain far from defined. Indeed, even the most basic questions, such as whether the radial atrophy of muscle fibers is driven by the radial atrophy of myofibrils and/or myofibril hypoplasia, have yet to be answered. In this review, we thoroughly summarize what is known about the macroscopic, microscopic, and ultrastructural adaptations that mediated disuse-induced atrophy and highlight some of the major gaps in knowledge that need to be filled.
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Affiliation(s)
- Ramy K. A. Sayed
- Department of Comparative Biosciences, University of Wisconsin—Madison, Madison, WI 53706, USA; (R.K.A.S.); (J.E.H.); (K.W.J.)
- School of Veterinary Medicine, University of Wisconsin—Madison, Madison, WI 53706, USA
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Sohag University, Sohag 82524, Egypt
| | - Jamie E. Hibbert
- Department of Comparative Biosciences, University of Wisconsin—Madison, Madison, WI 53706, USA; (R.K.A.S.); (J.E.H.); (K.W.J.)
- School of Veterinary Medicine, University of Wisconsin—Madison, Madison, WI 53706, USA
| | - Kent W. Jorgenson
- Department of Comparative Biosciences, University of Wisconsin—Madison, Madison, WI 53706, USA; (R.K.A.S.); (J.E.H.); (K.W.J.)
- School of Veterinary Medicine, University of Wisconsin—Madison, Madison, WI 53706, USA
| | - Troy A. Hornberger
- Department of Comparative Biosciences, University of Wisconsin—Madison, Madison, WI 53706, USA; (R.K.A.S.); (J.E.H.); (K.W.J.)
- School of Veterinary Medicine, University of Wisconsin—Madison, Madison, WI 53706, USA
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26
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Saloň A, Çiftci GM, Zubac D, Šimunič B, Pišot R, Narici M, Fredriksen PM, Nkeh-Chungag BN, Sourij H, Šerý O, Schmid-Zalaudek K, Steuber B, De Boever P, Goswami N. Retinal venular vessel diameters are smaller during ten days of bed rest. Sci Rep 2023; 13:19258. [PMID: 37935771 PMCID: PMC10630473 DOI: 10.1038/s41598-023-46177-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/28/2023] [Indexed: 11/09/2023] Open
Abstract
Older individuals experience cardiovascular dysfunction during extended bedridden hospital or care home stays. Bed rest is also used as a model to simulate accelerated vascular deconditioning occurring during spaceflight. This study investigates changes in retinal microcirculation during a ten-day bed rest protocol. Ten healthy young males (22.9 ± 4.7 years; body mass index: 23.6 ± 2.5 kg·m-2) participated in a strictly controlled repeated-measures bed rest study lasting ten days. High-resolution images were obtained using a hand-held fundus camera at baseline, daily during the 10 days of bed rest, and 1 day after re-ambulation. Retinal vessel analysis was performed using a semi-automated software system to obtain metrics for retinal arteriolar and venular diameters, central retinal artery equivalent and central retinal vein equivalent, respectively. Data analysis employed a mixed linear model. At the end of the bed rest period, a significant decrease in retinal venular diameter was observed, indicated by a significantly lower central retinal vein equivalent (from 226.1 µm, CI 8.90, to 211.4 µm, CI 8.28, p = .026), while no significant changes in central retinal artery equivalent were noted. Prolonged bed rest confinement resulted in a significant (up to 6.5%) reduction in retinal venular diameter. These findings suggest that the changes in retinal venular diameter during bedrest may be attributed to plasma volume losses and reflect overall (cardio)-vascular deconditioning.
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Affiliation(s)
- Adam Saloň
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria
| | - Göktuğ Mert Çiftci
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Department of Psychiatry, University Hospital Münster, Münster, Germany
| | - Damir Zubac
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
- Department 1 of Internal Medicine, Centre for Integrated Oncology, Aachen, Bonn, Cologne, Düsseldorf, University Hospital of Cologne, Cologne, Germany
| | - Boštjan Šimunič
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
| | - Rado Pišot
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
| | - Marco Narici
- Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Per Morten Fredriksen
- Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Benedicta Ngwenchi Nkeh-Chungag
- Department of Biological and Environmental Sciences, Faculty of Health Sciences, Walter Sisulu University PBX1, Mthatha, 5117, South Africa
| | - Harald Sourij
- Internal Medicine, Division of Endocrinology and Diabetology, Interdisciplinary Metabolic Medicine Trials Unit, Medical University of Graz, Graz, Austria
| | - Omar Šerý
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00, Brno, Czech Republic
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Veveří 97, 602 00, Brno, Czech Republic
| | - Karin Schmid-Zalaudek
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria
| | - Bianca Steuber
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria
| | - Patrick De Boever
- Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | - Nandu Goswami
- Division of Physiology & Pathophysiology, Otto Loewi Research Center for Vascular Biology, Immunology, and Inflammation, Medical University of Graz, Graz, Austria.
- Research Unit "Gravitational Physiology and Medicine", Physiology, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/D.05, 8010, Graz, Austria.
- Integrative Health, Alma Mater Europaea Maribor, Maribor, Slovenia.
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates.
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Pan C, Zhang Y, Yan J, Zhou Y, Wang S, Liu X, Zhang P, Yang H. Extreme environments and human health: From the immune microenvironments to immune cells. ENVIRONMENTAL RESEARCH 2023; 236:116800. [PMID: 37527745 DOI: 10.1016/j.envres.2023.116800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 07/20/2023] [Accepted: 07/29/2023] [Indexed: 08/03/2023]
Abstract
Exposure to extreme environments causes specific acute and chronic physiological responses in humans. The adaptation and the physiological processes under extreme environments predominantly affect multiple functional systems of the organism, in particular, the immune system. Dysfunction of the immune system affected by several extreme environments (including hyperbaric environment, hypoxia, blast shock, microgravity, hypergravity, radiation exposure, and magnetic environment) has been observed from clinical macroscopic symptoms to intracorporal immune microenvironments. Therefore, simulated extreme conditions are engineered for verifying the main influenced characteristics and factors in the immune microenvironments. This review summarizes the responses of immune microenvironments to these extreme environments during in vivo or in vitro exposure, and the approaches of engineering simulated extreme environments in recent decades. The related microenvironment engineering, signaling pathways, molecular mechanisms, clinical therapy, and prevention strategies are also discussed.
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Affiliation(s)
- Chengwei Pan
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Yuzhi Zhang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Jinxiao Yan
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Yidan Zhou
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Sijie Wang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Xiru Liu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
| | - Pan Zhang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; School of Food Science and Engineering, Shaanxi University of Science & Technology, 710021, China.
| | - Hui Yang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, China; Research Center of Special Environmental Biomechanics & Medical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China.
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28
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Clément G, Kuldavletova O, Macaulay TR, Wood SJ, Navarro Morales DC, Toupet M, Hautefort C, Van Nechel C, Quarck G, Denise P. Cognitive and balance functions of astronauts after spaceflight are comparable to those of individuals with bilateral vestibulopathy. Front Neurol 2023; 14:1284029. [PMID: 37965165 PMCID: PMC10641777 DOI: 10.3389/fneur.2023.1284029] [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: 08/27/2023] [Accepted: 10/06/2023] [Indexed: 11/16/2023] Open
Abstract
Introduction This study compares the balance control and cognitive responses of subjects with bilateral vestibulopathy (BVP) to those of astronauts immediately after they return from long-duration spaceflight on board the International Space Station. Methods Twenty-eight astronauts and thirty subjects with BVP performed five tests using the same procedures: sit-to-stand, walk-and-turn, tandem walk, duration judgment, and reaction time. Results Compared to the astronauts' preflight responses, the BVP subjects' responses were impaired in all five tests. However, the BVP subjects' performance during the walk-and-turn and the tandem walk tests were comparable to the astronauts' performance on the day they returned from space. Moreover, the BVP subjects' time perception and reaction time were comparable to those of the astronauts during spaceflight. The BVP subjects performed the sit-to-stand test at a level that fell between the astronauts' performance on the day of landing and 1 day later. Discussion These results indicate that the alterations in dynamic balance control, time perception, and reaction time that astronauts experience after spaceflight are likely driven by central vestibular adaptations. Vestibular and somatosensory training in orbit and vestibular rehabilitation after spaceflight could be effective countermeasures for mitigating these post-flight performance decrements.
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Affiliation(s)
- Gilles Clément
- Université de Caen Normandie, INSERM, COMETE U1075, CYCERON, CHU de Caen, Normandie Université, Caen, France
- KBR, Houston, TX, United States
| | - Olga Kuldavletova
- Université de Caen Normandie, INSERM, COMETE U1075, CYCERON, CHU de Caen, Normandie Université, Caen, France
| | | | - Scott J. Wood
- NASA Johnson Space Center, Houston, TX, United States
| | - Deborah C. Navarro Morales
- Université de Caen Normandie, INSERM, COMETE U1075, CYCERON, CHU de Caen, Normandie Université, Caen, France
| | - Michel Toupet
- Centre d'Explorations Fonctionnelles Oto-Neurologiques, Paris, France
| | - Charlotte Hautefort
- Université de Paris Cité, INSERM U1141, Paris, France
- Department of Otorhinolaryngology, Assistance Publique, Hôpitaux de Paris, Lariboisière Hospital, Paris, France
| | | | - Gaëlle Quarck
- Université de Caen Normandie, INSERM, COMETE U1075, CYCERON, CHU de Caen, Normandie Université, Caen, France
| | - Pierre Denise
- Université de Caen Normandie, INSERM, COMETE U1075, CYCERON, CHU de Caen, Normandie Université, Caen, France
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McGregor HR, Lee JK, Mulder ER, De Dios YE, Beltran NE, Wood SJ, Bloomberg JJ, Mulavara AP, Seidler RD. Artificial gravity during a spaceflight analog alters brain sensory connectivity. Neuroimage 2023; 278:120261. [PMID: 37422277 DOI: 10.1016/j.neuroimage.2023.120261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 05/06/2023] [Accepted: 06/29/2023] [Indexed: 07/10/2023] Open
Abstract
Spaceflight has numerous untoward effects on human physiology. Various countermeasures are under investigation including artificial gravity (AG). Here, we investigated whether AG alters resting-state brain functional connectivity changes during head-down tilt bed rest (HDBR), a spaceflight analog. Participants underwent 60 days of HDBR. Two groups received daily AG administered either continuously (cAG) or intermittently (iAG). A control group received no AG. We assessed resting-state functional connectivity before, during, and after HDBR. We also measured balance and mobility changes from pre- to post-HDBR. We examined how functional connectivity changes throughout HDBR and whether AG is associated with differential effects. We found differential connectivity changes by group between posterior parietal cortex and multiple somatosensory regions. The control group exhibited increased functional connectivity between these regions throughout HDBR whereas the cAG group showed decreased functional connectivity. This finding suggests that AG alters somatosensory reweighting during HDBR. We also observed brain-behavioral correlations that differed significantly by group. Control group participants who showed increased connectivity between the putamen and somatosensory cortex exhibited greater mobility declines post-HDBR. For the cAG group, increased connectivity between these regions was associated with little to no mobility declines post-HDBR. This suggests that when somatosensory stimulation is provided via AG, functional connectivity increases between the putamen and somatosensory cortex are compensatory in nature, resulting in reduced mobility declines. Given these findings, AG may be an effective countermeasure for the reduced somatosensory stimulation that occurs in both microgravity and HDBR.
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Affiliation(s)
- Heather R McGregor
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
| | - Jessica K Lee
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States; Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Edwin R Mulder
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | | | | | - Scott J Wood
- NASA Johnson Space Center, Houston, TX, United States
| | | | | | - Rachael D Seidler
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States; Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States.
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Tidwell JB, Taylor JA, Collins HR, Chamberlin JH, Barisano G, Sepehrband F, Turner MD, Gauthier G, Mulder ER, Gerlach DA, Roberts DR. Longitudinal Changes in Cerebral Perfusion, Perivascular Space Volume, and Ventricular Volume in a Healthy Cohort Undergoing a Spaceflight Analog. AJNR Am J Neuroradiol 2023; 44:1026-1031. [PMID: 37562828 PMCID: PMC10494950 DOI: 10.3174/ajnr.a7949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 06/25/2023] [Indexed: 08/12/2023]
Abstract
BACKGROUND AND PURPOSE A global decrease in brain perfusion has recently been reported during exposure to a ground-based spaceflight analog. Considering that CSF and glymphatic flow are hypothesized to be propelled by arterial pulsations, it is unknown whether a change in perfusion would impact these CSF compartments. The aim of the current study was to evaluate the relationship among changes in cerebral perfusion, ventricular volume, and perivascular space volume before, during, and after a spaceflight analog. MATERIALS AND METHODS Eleven healthy participants underwent 30 days of bed rest at 6° head-down tilt with 0.5% atmospheric CO2 as a spaceflight analog. For each participant, 6 MR imaging brain scans, including perfusion and anatomic-weighted T1 sequences, were obtained before, during, and after the analog period. Global perfusion, ventricular volume, and perivascular space volume time courses were constructed and evaluated with repeated measures ANOVAs. RESULTS Global perfusion followed a divergent time trajectory from ventricular and perivascular space volume, with perfusion decreasing during the analog, whereas ventricular and perivascular space volume increased (P < .001). These patterns subsequently reversed during the 2-week recovery period. CONCLUSIONS The patterns of change in brain physiology observed in healthy participants suggest a relationship between cerebral perfusion and CSF homeostasis. Further study is warranted to determine whether a causal relationship exists and whether similar neurophysiologic responses occur during spaceflight.
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Affiliation(s)
- J B Tidwell
- From the Department of Radiology and Radiological Science (J.B.T., J.A.T., H.R.C., J.H.C., M.D.T., G.G., D.R.R.), Medical University of South Carolina; Charleston, South Carolina
| | - J A Taylor
- From the Department of Radiology and Radiological Science (J.B.T., J.A.T., H.R.C., J.H.C., M.D.T., G.G., D.R.R.), Medical University of South Carolina; Charleston, South Carolina
| | - H R Collins
- From the Department of Radiology and Radiological Science (J.B.T., J.A.T., H.R.C., J.H.C., M.D.T., G.G., D.R.R.), Medical University of South Carolina; Charleston, South Carolina
| | - J H Chamberlin
- From the Department of Radiology and Radiological Science (J.B.T., J.A.T., H.R.C., J.H.C., M.D.T., G.G., D.R.R.), Medical University of South Carolina; Charleston, South Carolina
| | - G Barisano
- Laboratory of Neuroimaging (F.S.), University of Southern California, Los Angeles, California
| | - F Sepehrband
- Department of Neurosurgery (G.B.), Stanford University, Stanford, California
| | - M D Turner
- From the Department of Radiology and Radiological Science (J.B.T., J.A.T., H.R.C., J.H.C., M.D.T., G.G., D.R.R.), Medical University of South Carolina; Charleston, South Carolina
| | - G Gauthier
- From the Department of Radiology and Radiological Science (J.B.T., J.A.T., H.R.C., J.H.C., M.D.T., G.G., D.R.R.), Medical University of South Carolina; Charleston, South Carolina
| | - E R Mulder
- Department of Neurosurgery (G.B.), Stanford University, Stanford, California
| | - D A Gerlach
- Department of Neurosurgery (G.B.), Stanford University, Stanford, California
| | - D R Roberts
- From the Department of Radiology and Radiological Science (J.B.T., J.A.T., H.R.C., J.H.C., M.D.T., G.G., D.R.R.), Medical University of South Carolina; Charleston, South Carolina
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Thomasius F, Pesta D, Rittweger J. Adjuvant pharmacological strategies for the musculoskeletal system during long-term space missions. Br J Clin Pharmacol 2023. [PMID: 37559171 DOI: 10.1111/bcp.15877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/29/2023] [Accepted: 08/01/2023] [Indexed: 08/11/2023] Open
Abstract
Despite 2 h of daily exercise training, muscle wasting and bone loss are still present after 6-month missions to the international space station. Some crew members lose bone much faster than others. In preparation for missions to the Moon and Mars, space agencies are therefore reviewing their countermeasure portfolios. Here, we discuss the potential of current pharmacological strategies. Bone loss in space is fuelled by bone resorption. Alendronate, an oral bisphosphonate, reduced bone losses in experimental bed rest and space. However, gastrointestinal side effects precluded its further utilization in space. Zoledronate (a potent bisphosphonate), denosumab (RANKL antagonist) and romosozumab (sclerostin antagonist) are all administered via injection. They effectively suppress bone resorption and are routinely prescribed against osteoporosis. Their serious adverse effects, namely, osteonecrosis of the jaw and atypical femur fractures occur very rarely when the usage is limited to 1 or 2 years. Hence, utilization of one of these compounds may outweigh the bone risks of space travelling, in particular in those with high bone resorption rates. Muscle wasting in space is likely due to hampered muscle protein synthesis. Even though this might theoretically be countered by the synthesis-boosting effects of anabolic steroids, the practical grounds for such recommendation are currently weak. Moreover, they reveal their full potential only when combined with an anabolic exercise stimulus, for example, via strength training. It therefore seems that a combination of exercise and pharmacological countermeasures should be considered for musculoskeletal health on the way to the Moon and Mars and back.
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Affiliation(s)
| | - Dominik Pesta
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Centre for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Jörn Rittweger
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Pediatrics and Adolescent Medicine, University Hospital Cologne, Cologne, Germany
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Hoenemann JN, Moestl S, van Herwaarden AE, Diedrich A, Mulder E, Frett T, Petrat G, Pustowalow W, Arz M, Heusser K, Lee S, Jordan J, Tank J, Hoffmann F. Effects of daily artificial gravity training on orthostatic tolerance following 60-day strict head-down tilt bedrest. Clin Auton Res 2023; 33:401-410. [PMID: 37347452 PMCID: PMC10439060 DOI: 10.1007/s10286-023-00959-5] [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: 03/01/2023] [Accepted: 05/26/2023] [Indexed: 06/23/2023]
Abstract
PURPOSE Orthostatic intolerance commonly occurs following immobilization or space flight. We hypothesized that daily artificial gravity training through short-arm centrifugation could help to maintain orthostatic tolerance following head-down tilt bedrest, which is an established terrestrial model for weightlessness. METHODS We studied 24 healthy persons (eight women; age 33.3 ± 9.0 years; BMI 24.3 ± 2.1 kg/m2) who participated in the 60-days head-down tilt bedrest (AGBRESA) study. They were assigned to 30 min/day continuous or 6 × 5 min intermittent short-arm centrifugation with 1Gz at the center of mass or a control group. We performed head-up tilt testing with incremental lower-body negative pressure until presyncope before and after bedrest. We recorded an electrocardiogram, beat-to-beat finger blood pressure, and brachial blood pressure and obtained blood samples from an antecubital venous catheter. Orthostatic tolerance was defined as time to presyncope. We related changes in orthostatic tolerance to changes in plasma volume determined by carbon dioxide rebreathing. RESULTS Compared with baseline measurements, supine and upright heart rate increased in all three groups following head-down tilt bedrest. Compared with baseline measurements, time to presyncope decreased by 323 ± 235 s with continuous centrifugation, by 296 ± 508 s with intermittent centrifugation, and by 801 ± 354 s in the control group (p = 0.0249 between interventions). The change in orthostatic tolerance was not correlated with changes in plasma volume. CONCLUSIONS Daily artificial gravity training on a short-arm centrifuge attenuated the reduction in orthostatic tolerance after 60 days of head-down tilt bedrest.
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Affiliation(s)
- J-N Hoenemann
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
- Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care, University of Cologne, Kerpener Str. 62, 50937, Cologne, Germany
| | - S Moestl
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
| | - A E van Herwaarden
- Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA, Nijmegen, Netherlands
| | - A Diedrich
- Department of Medicine, Division of Clinical Pharmacology, Autonomic Dysfunction Service, Vanderbilt University, Nashville, TN, USA
| | - E Mulder
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
| | - T Frett
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
| | - G Petrat
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
| | - W Pustowalow
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
| | - M Arz
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
| | - K Heusser
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
| | - S Lee
- NASA JSC KBR Wyle, Houston, TX, USA
| | - J Jordan
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
- Head of Aerospace Medicine, University of Cologne, Albertus-Magnus-Platz, 50923, Cologne, Germany
| | - J Tank
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany.
| | - F Hoffmann
- German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany
- Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care, University of Cologne, Kerpener Str. 62, 50937, Cologne, Germany
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Seidler R, Tays G, Hupfeld K, McGregor H, Beltran N, de Dios Y, Mulder E, Bloomberg J, Mulavara A, Wood S. Daily Artificial Gravity Partially Mitigates Vestibular Processing Changes Associated with Head-down Tilt Bedrest. RESEARCH SQUARE 2023:rs.3.rs-3157785. [PMID: 37502989 PMCID: PMC10371135 DOI: 10.21203/rs.3.rs-3157785/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Microgravity alters vestibular signaling and reduces body loading, driving sensory reweighting and adaptation. The unloading effects can be modelled using head down tilt bedrest (HDT). Artificial gravity (AG) has been hypothesized to serve as an integrated countermeasure for the physiological declines associated with HDT and spaceflight. Here, we examined the efficacy of 30 minutes of daily AG to counteract brain and behavior changes that arise from 60 days of HDT. One group of participants received 30 minutes of AG daily (AG; n = 16) while in HDT, and another group served as controls, spending 60 days in HDT bedrest with no AG (CTRL; n = 8). We examined how HDT and AG affect vestibular processing by collecting fMRI scans from participants as they received vestibular stimulation. We collected these data prior to, during (2x), and post HDT. We assessed brain activation initially in 10 regions of interest (ROIs) and then conducted an exploratory whole brain analysis. The AG group showed no changes in brain activation during vestibular stimulation in a cerebellar ROI, whereas the CTRL group showed decreased cerebellar activation specific to the HDT phase. Additionally, those that received AG and showed little pre- to post-bed rest changes in left OP2 activation during HDT had better post-HDT balance performance. Exploratory whole brain analyses identified increased pre- to during-HDT activation in the CTRL group in the right precentral gyrus and the right inferior frontal gyrus specific to HDT, where the AG group maintained pre-HDT activation levels. Together, these results indicate that AG could mitigate brain activation changes in vestibular processing in a manner that is associated with better balance performance after HDT.
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Jagtap S, Kumar A, Mahale B, Dixit J, Kalange AE, Kanawade R, Gangal S, Vidyasagar P. Response of cardiac pulse parameters in humans at various inclinations via 360° rotating platform for simulated microgravity perspective. NPJ Microgravity 2023; 9:54. [PMID: 37463938 DOI: 10.1038/s41526-023-00301-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 07/02/2023] [Indexed: 07/20/2023] Open
Abstract
On the Earth, the human body is designed and adapted to function under uniform gravitational acceleration. However, exposure to microgravity or weightlessness as experienced by astronauts in space causes significant alterations in the functioning of the human cardiovascular system. Due to limitations in using real microgravity platforms, researchers opted for various ground-based microgravity analogs including head-down tilt (HDT) at fixed inclination. However, in the present study, an investigation of response of various cardiac parameters and their circulatory adaptation in 18 healthy male subjects was undertaken by using an indigenously developed 360° rotating platform. Cardiac pulse was recorded from 0° to 360° in steps of 30° inclination using piezoelectric pulse sensor (MLT1010) and associated cardiac parameters were analyzed. The results showed significant changes in the pulse shape while an interesting oscillating pattern was observed in associated cardiac parameters when rotated from 0° to 360°. The response of cardiac parameters became normal after returning to supine posture indicating the ability of the cardiovascular system to reversibly adapt to the postural changes. The observed changes in cardiac parameters at an inclination of 270°, in particular, were found to be comparable with spaceflight studies. Based on the obtained results and the proposed extended version of fluid redistribution mechanism, we herewith hypothesize that the rotation of a subject to head down tilt inclination (270°) along with other inclinations could represent a better microgravity analog for understanding the cumulative cardiac response of astronauts in space, particularly for short duration space missions.
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Affiliation(s)
- Sagar Jagtap
- Department of Physics, Haribhai V. Desai College, Pune, MS, 411002, India.
| | - Ajay Kumar
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, MS, 411008, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Bhoopesh Mahale
- Department of Electronics, Savitribai Phule Pune University, Pune, MS, 411007, India
| | - Jyotsana Dixit
- Department of Microbiology, Savitribai Phule Pune University, Pune, MS, 411007, India
| | - Ashok E Kalange
- Department of Physics, Tuljaram Chaturchand College, Baramati, Dist., Pune, 413102, MS, India
| | - Rajesh Kanawade
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, MS, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Shashikala Gangal
- Department of Electronics, Savitribai Phule Pune University, Pune, MS, 411007, India
| | - Pandit Vidyasagar
- Department of Physics, Savitribai Phule Pune University, Pune, MS, 411007, India.
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Hedge ET, Vico L, Hughson RL, Mastrandrea CJ. Effects of Posture and Walking on Tibial Vascular Hemodynamics Before and After 14 Days of Head-Down Bed Rest. JBMR Plus 2023; 7:e10756. [PMID: 37457881 PMCID: PMC10339089 DOI: 10.1002/jbm4.10756] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 04/17/2023] [Indexed: 07/18/2023] Open
Abstract
Human skeletal hemodynamics remain understudied. Neither assessments in weight-bearing bones during walking nor following periods of immobility exist, despite knowledge of altered nutrient-artery characteristics after short-duration unloading in rodents. We studied 12 older adults (8 females, aged 59 ± 3 years) who participated in ambulatory near-infrared spectroscopy (NIRS) assessments of tibial hemodynamics before (PRE) and after (POST) 14 days of head-down bed rest (HDBR), with most performing daily resistance and aerobic exercise countermeasures during HDBR. Continual simultaneous NIRS recordings were acquired over the proximal anteromedial tibial prominence of the right lower leg and ipsilateral lateral head of the gastrocnemius muscle during supine rest, walking, and standing. During 10 minutes of walking, desaturation kinetics in the tibia were slower (time to 95% nadir values 125.4 ± 56.8 s versus 55.0 ± 30.1 s, p = 0.0014). Tibial tissue saturation index (TSI) immediately fell (-9.9 ± 4.55) and did not completely recover by the end of 10 minutes of walking (-7.4 ± 6.7%, p = 0.027). Upon standing, total hemoglobin (tHb) kinetics were faster in the tibia (p < 0.0001), whereas HDBR resulted in faster oxygenated hemoglogin (O2Hb) kinetics in both tissues (p = 0.039). After the walk-to-stand transition, changes in O2Hb (p = 0.0022) and tHb (p = 0.0047) were attenuated in the tibia alone after bed rest. Comparisons of NIRS-derived variables during ambulation and changes in posture revealed potentially deleterious adaptations of feed vessels after HDBR. We identify important and novel tibial hemodynamics in humans during ambulation before and after bed rest, necessitating further investigation. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Eric T Hedge
- Schlegel‐UW Research Institute for AgingWaterlooCanada
- Department of Kinesiology and Health SciencesUniversity of WaterlooWaterlooCanada
| | - Laurence Vico
- U1059 INSERM—SAINBIOSE (Santé Ingéniérie Biologie St‐Etienne) Campus Santé InnovationUniversité Jean MonnetSaint‐Priest‐en‐JarezFrance
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Stratis D, Trudel G, Rocheleau L, Pelchat M, Laneuville O. The transcriptome response of astronaut leukocytes to long missions aboard the International Space Station reveals immune modulation. Front Immunol 2023; 14:1171103. [PMID: 37426644 PMCID: PMC10324659 DOI: 10.3389/fimmu.2023.1171103] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/18/2023] [Indexed: 07/11/2023] Open
Abstract
Introduction Spaceflight leads to the deconditioning of multiple body systems including the immune system. We sought to characterize the molecular response involved by capturing changes in leukocyte transcriptomes from astronauts transitioning to and from long-duration spaceflight. Methods Fourteen male and female astronauts with ~6-month- long missions aboard the International Space Station (ISS) had 10 blood samples collected throughout the three phases of the study: one pre-flight (PF), four in-flight (IF) while onboard the ISS, and five upon return to Earth (R). We measured gene expression through RNA sequencing of leukocytes and applied generalized linear modeling to assess differential expression across all 10 time points followed by the analysis of selected time points and functional enrichment of changing genes to identify shifts in biological processes. Results Our temporal analysis identified 276 differentially expressed transcripts grouped into two clusters (C) showing opposite profiles of expression with transitions to and from spaceflight: (C1) decrease-then-increase and (C2) increase-then-decrease. Both clusters converged toward average expression between ~2 and ~6 months in space. Further analysis of spaceflight transitions identified the decrease-then-increase pattern with most changes: 112 downregulated genes between PF and early spaceflight and 135 upregulated genes between late IF and R. Interestingly, 100 genes were both downregulated when reaching space and upregulated when landing on Earth. Functional enrichment at the transition to space related to immune suppression increased cell housekeeping functions and reduced cell proliferation. In contrast, egress to Earth is related to immune reactivation. Conclusion The leukocytes' transcriptome changes describe rapid adaptations in response to entering space followed by opposite changes upon returning to Earth. These results shed light on immune modulation in space and highlight the major adaptive changes in cellular activity engaged to adapt to extreme environments.
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Affiliation(s)
- Daniel Stratis
- 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, Canada
- Department of Medicine, Division of Physiatry, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Lynda Rocheleau
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Martin Pelchat
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Odette Laneuville
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
- Bone and Joint Research Laboratory, Ottawa Hospital Research Institute, Ottawa, ON, Canada
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Tays GD, Hupfeld KE, McGregor HR, Beltran NE, Kofman IS, De Dios YE, Mulder ER, Bloomberg JJ, Mulavara AP, Wood SJ, Seidler RD. Daily artificial gravity is associated with greater neural efficiency during sensorimotor adaptation. Cereb Cortex 2023; 33:8011-8023. [PMID: 36958815 PMCID: PMC10267627 DOI: 10.1093/cercor/bhad094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/25/2023] Open
Abstract
Altered vestibular signaling and body unloading in microgravity results in sensory reweighting and adaptation. Microgravity effects are well-replicated in head-down tilt bed rest (HDBR). Artificial gravity (AG) is a potential countermeasure to mitigate the effects of microgravity on human physiology and performance. We examined the effectiveness of daily AG for mitigating brain and/or behavioral changes in 60 days of HDBR. One group received AG for 30 minutes daily (AG; n = 16) and a control group spent the same time in HDBR but received no AG (CTRL; n = 8). All participants performed a sensorimotor adaptation task five times during fMRI scanning: twice prior to HDBR, twice during HDBR, and once following HDBR. The AG group showed similar behavioral adaptation effects compared with the CTRLs. We identified decreased brain activation in the AG group from pre to late HDBR in the cerebellum for the task baseline portion and in the thalamus, calcarine, cuneus, premotor cortices, and superior frontal gyrus in the AG group during the early adaptation phase. The two groups also exhibited differential brain-behavior correlations. Together, these results suggest that AG may result in a reduced recruitment of brain activity for basic motor processes and sensorimotor adaptation. These effects may stem from the somatosensory and vestibular stimulation that occur with AG.
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Affiliation(s)
- Grant D Tays
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32603, USA
| | - Kathleen E Hupfeld
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32603, USA
| | - Heather R McGregor
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32603, USA
| | | | | | | | | | | | | | - Scott J Wood
- NASA Johnson Space Center, Houston, TX 77058, USA
| | - Rachael D Seidler
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32603, USA
- Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32603, USA
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Roggan MD, Kronenberg J, Wollert E, Hoffmann S, Nisar H, Konda B, Diegeler S, Liemersdorf C, Hellweg CE. Unraveling astrocyte behavior in the space brain: Radiation response of primary astrocytes. Front Public Health 2023; 11:1063250. [PMID: 37089489 PMCID: PMC10116417 DOI: 10.3389/fpubh.2023.1063250] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/06/2023] [Indexed: 04/09/2023] Open
Abstract
IntroductionExposure to space conditions during crewed long-term exploration missions can cause several health risks for astronauts. Space radiation, isolation and microgravity are major limiting factors. The role of astrocytes in cognitive disturbances by space radiation is unknown. Astrocytes' response toward low linear energy transfer (LET) X-rays and high-LET carbon (12C) and iron (56Fe) ions was compared to reveal possible effects of space-relevant high-LET radiation. Since astronauts are exposed to ionizing radiation and microgravity during space missions, the effect of simulated microgravity on DNA damage induction and repair was investigated.MethodsPrimary murine cortical astrocytes were irradiated with different doses of X-rays, 12C and 56Fe ions at the heavy ion accelerator GSI. DNA damage and repair (γH2AX, 53BP1), cell proliferation (Ki-67), astrocytes' reactivity (GFAP) and NF-κB pathway activation (p65) were analyzed by immunofluorescence microscopy. Cell cycle progression was investigated by flow cytometry of DNA content. Gene expression changes after exposure to X- rays were investigated by mRNA-sequencing. RT-qPCR for several genes of interest was performed with RNA from X-rays- and heavy-ion-irradiated astrocytes: Cdkn1a, Cdkn2a, Gfap, Tnf, Il1β, Il6, and Tgfβ1. Levels of the pro inflammatory cytokine IL-6 were determined using ELISA. DNA damage response was investigated after exposure to X-rays followed by incubation on a 2D clinostat to simulate the conditions of microgravity.ResultsAstrocytes showed distinct responses toward the three different radiation qualities. Induction of radiation-induced DNA double strand breaks (DSBs) and the respective repair was dose-, LET- and time-dependent. Simulated microgravity had no significant influence on DNA DSB repair. Proliferation and cell cycle progression was not affected by radiation qualities examined in this study. Astrocytes expressed IL-6 and GFAP with constitutive NF-κB activity independent of radiation exposure. mRNA sequencing of X-irradiated astrocytes revealed downregulation of 66 genes involved in DNA damage response and repair, mitosis, proliferation and cell cycle regulation.DiscussionIn conclusion, primary murine astrocytes are DNA repair proficient irrespective of radiation quality. Only minor gene expression changes were observed after X-ray exposure and reactivity was not induced. Co-culture of astrocytes with microglial cells, brain organoids or organotypic brain slice culture experiments might reveal whether astrocytes show a more pronounced radiation response in more complex network architectures in the presence of other neuronal cell types.
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Affiliation(s)
- Marie Denise Roggan
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Jessica Kronenberg
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Microgravity User Support Center (MUSC), German Aerospace Center (DLR), Cologne, Germany
| | - Esther Wollert
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Sven Hoffmann
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Hasan Nisar
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Medical Sciences, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Bikash Konda
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Sebastian Diegeler
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, United States
| | - Christian Liemersdorf
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Christine E. Hellweg
- Department of Radiation Biology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- *Correspondence: Christine E. Hellweg
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Trim WV, Walhin JP, Koumanov F, Turner JE, Shur NF, Simpson EJ, Macdonald IA, Greenhaff PL, Thompson D. The impact of physical inactivity on glucose homeostasis when diet is adjusted to maintain energy balance in healthy, young males. Clin Nutr 2023; 42:532-540. [PMID: 36857962 DOI: 10.1016/j.clnu.2023.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/31/2023] [Accepted: 02/09/2023] [Indexed: 02/18/2023]
Abstract
BACKGROUND & AIMS It is unclear if dietary adjustments to maintain energy balance during reduced physical activity can offset inactivity-induced reductions in insulin sensitivity and glucose disposal to produce normal daily glucose concentrations and meal responses. Therefore, the aim of the present study was to examine the impact of long-term physical inactivity (60 days of bed rest) on daily glycemia when in energy balance. METHODS Interstitial glucose concentrations were measured using Continuous Glucose Monitoring Systems (CGMS) for 5 days before and towards the end of bed rest in 20 healthy, young males (Age: 34 ± 8 years; BMI: 23.5 ± 1.8 kg/m2). Energy intake was reduced during bed rest to match energy expenditure, but the types of foods and timing of meals was maintained. Fasting venous glucose and insulin concentrations were determined, as well as the change in whole-body glucose disposal using a hyperinsulinemic-euglycemic clamp (HIEC). RESULTS Following long-term bed rest, fasting plasma insulin concentration increased 40% (p = 0.004) and glucose disposal during the HIEC decreased 24% (p < 0.001). Interstitial daily glucose total area under the curve (tAUC) from pre-to post-bed rest increased on average by 6% (p = 0.041), despite a 20 and 25% reduction in total caloric and carbohydrate intake, respectively. The nocturnal period (00:00-06:00) showed the greatest change to glycemia with glucose tAUC for this period increasing by 9% (p = 0.005). CGMS measures of daily glycemic variability (SD, J-Index, M-value and MAG) were not changed during bed rest. CONCLUSIONS Reduced physical activity (bed rest) increases glycemia even when daily energy intake is reduced to maintain energy balance. However, the disturbance to daily glucose homeostasis was much more modest than the reduced capacity to dispose of glucose, and glycemic variability was not negatively affected by bed rest, likely due to positive mitigating effects from the contemporaneous reduction in dietary energy and carbohydrate intake. CLINICAL TRIALS RECORD NCT03594799 (registered July 20, 2018) (https://clinicaltrials.gov/ct2/show/NCT03594799).
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Affiliation(s)
- William V Trim
- University of Bath, Centre for Nutrition, Exercise and Metabolism (CNEM), Department for Health, United Kingdom
| | - Jean-Philippe Walhin
- University of Bath, Centre for Nutrition, Exercise and Metabolism (CNEM), Department for Health, United Kingdom
| | - Francoise Koumanov
- University of Bath, Centre for Nutrition, Exercise and Metabolism (CNEM), Department for Health, United Kingdom
| | - James E Turner
- University of Bath, Centre for Nutrition, Exercise and Metabolism (CNEM), Department for Health, United Kingdom
| | - Natalie F Shur
- Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, School of Life Sciences, The University of Nottingham, Nottingham, United Kingdom; National Institute for Health and Care Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom
| | - Elizabeth J Simpson
- National Institute for Health and Care Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom; MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, Schools of Life Sciences and Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Ian A Macdonald
- National Institute for Health and Care Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom; MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, Schools of Life Sciences and Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Paul L Greenhaff
- Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, School of Life Sciences, The University of Nottingham, Nottingham, United Kingdom; National Institute for Health and Care Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom; MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, Schools of Life Sciences and Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Dylan Thompson
- University of Bath, Centre for Nutrition, Exercise and Metabolism (CNEM), Department for Health, United Kingdom.
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Stratis D, Trudel G, Rocheleau L, Pelchat M, Laneuville O. The Characteristic Response of the Human Leukocyte Transcriptome to 60 Days of Bed Rest and to Reambulation. Med Sci Sports Exerc 2023; 55:365-375. [PMID: 36251376 DOI: 10.1249/mss.0000000000003071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
INTRODUCTION We sought to isolate the microgravity effect of spaceflight from other space stressors by characterizing the leukocytes' transcriptome of participants to a 60-d bed rest study; an Earth model of microgravity. METHODS Twenty healthy men received a nutritional supplement or not and 10 blood samples were collected throughout three study phases: baseline data collection (BDC) (BDC-12, BDC-11), head-down tilt (HDT) bed rest (HDT1, HDT2, HDT30, HDT60), and reambulation (R1, R2, R12, R30). We measured gene expression through RNA sequencing of leukocytes, applied generalized linear models to assess differential expression followed by enrichment analysis to identify temporal changes (model 1) and to measure the impact of a nutritional supplement (model 2). RESULTS Baseline transcriptomes included 14,624 protein-coding transcripts and showed both high intraindividual correlations (mean Kendall coefficient, 0.91 ± 0.04) and interindividual homogeneity (0.89 ± 0.03). We identified 2415 differentially expressed protein-coding transcripts grouping into six clusters (C1-C6). At phase transitions, clusters showed either a decrease-then-increase (C3 and C5) or an increase-then-decrease (C1, C2, C6) pattern. All six clusters converged toward average expression at HDT30 and HDT60. Gene ontology terms at baseline related to immune functions while in bed rest and reambulation related to sequestration of ions, immune response, cellular stress, and mineralization. The nutritional intervention had no effect. CONCLUSIONS The temporal profiles of leukocytes' transcriptomes emphasized the dynamic nature of gene expression occurring during and after bed rest. Enriched biological processes among the differentially expressed genes included immune related and unrelated responses. The convergence toward no differential expression at days 30 and 60 of bed rest suggests a hypometabolic state. Current findings can guide future work on the complex responses and adaptation mechanisms to microgravity.
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Affiliation(s)
- Daniel Stratis
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, Ontario, CANADA
| | | | - Lynda Rocheleau
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CANADA
| | - Martin Pelchat
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CANADA
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Saveko A, Bekreneva M, Ponomarev I, Zelenskaya I, Riabova A, Shigueva T, Kitov V, Abu Sheli N, Nosikova I, Rukavishnikov I, Sayenko D, Tomilovskaya E. Impact of different ground-based microgravity models on human sensorimotor system. Front Physiol 2023; 14:1085545. [PMID: 36875039 PMCID: PMC9974674 DOI: 10.3389/fphys.2023.1085545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/30/2023] [Indexed: 02/17/2023] Open
Abstract
This review includes current and updated information about various ground-based microgravity models and their impact on the human sensorimotor system. All known models of microgravity are imperfect in a simulation of the physiological effects of microgravity but have their advantages and disadvantages. This review points out that understanding the role of gravity in motion control requires consideration of data from different environments and in various contexts. The compiled information can be helpful to researchers to effectively plan experiments using ground-based models of the effects of space flight, depending on the problem posed.
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Affiliation(s)
- Alina Saveko
- Russian Federation State Scientific Center—Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia
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Liu X, Yan Z, Cai J, Wang D, Yang Y, Ding Y, Shao X, Hao X, Luo E, Guo XE, Luo P, Shen L, Jing D. Glucose- and glutamine-dependent bioenergetics sensitize bone mechanoresponse after unloading by modulating osteocyte calcium dynamics. J Clin Invest 2023; 133:164508. [PMID: 36512405 PMCID: PMC9888392 DOI: 10.1172/jci164508] [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: 08/15/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
Disuse osteoporosis is a metabolic bone disease resulting from skeletal unloading (e.g., during extended bed rest, limb immobilization, and spaceflight), and the slow and insufficient bone recovery during reambulation remains an unresolved medical challenge. Here, we demonstrated that loading-induced increase in bone architecture/strength was suppressed in skeletons previously exposed to unloading. This reduction in bone mechanosensitivity was directly associated with attenuated osteocytic Ca2+ oscillatory dynamics. The unloading-induced compromised osteocytic Ca2+ response to reloading resulted from the HIF-1α/PDK1 axis-mediated increase in glycolysis, and a subsequent reduction in ATP synthesis. HIF-1α also transcriptionally induced substantial glutaminase 2 expression and thereby glutamine addiction in osteocytes. Inhibition of glycolysis by blockade of PDK1 or glutamine supplementation restored the mechanosensitivity in those skeletons with previous unloading by fueling the tricarboxylic acid cycle and rescuing subsequent Ca2+ oscillations in osteocytes. Thus, we provide mechanistic insight into disuse-induced deterioration of bone mechanosensitivity and a promising therapeutic approach to accelerate bone recovery after long-duration disuse.
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Affiliation(s)
- Xiyu Liu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Zedong Yan
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Jing Cai
- College of Basic Medicine, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Dan Wang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Yongqing Yang
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Yuanjun Ding
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Xi Shao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Xiaoxia Hao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - X. Edward Guo
- Bone Bioengineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital
| | - Liangliang Shen
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China.,Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, and,Shaanxi Provincial Key Laboratory of Bioelectromagnetic Detection and Intelligent Perception, Fourth Military Medical University, Xi’an, China
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Zhang JY, Anderson AP. Performance Risks During Surface Extravehicular Activity and Potential Mitigation Using Multimodal Displays. Aerosp Med Hum Perform 2023; 94:34-41. [PMID: 36757234 DOI: 10.3357/amhp.6066.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND: Surface extravehicular activity (sEVA) will be a critical component of future human missions to the Moon. sEVA presents novel risks to astronaut crews not associated with microgravity operations due to fundamental differences in task demands, physiology, environment, and operations of working on the lunar surface. Multimodal spacesuit informatics displays have been proposed as a method of mitigating sEVA risk by increasing operator autonomy.METHODS: A formalized literature review was conducted. In total, 95 journal articles, conference papers, and technical reports were included. Characteristics of U.S. spacesuits were reviewed, ranging from the Apollo A7L to the xEMU Z-2.5. Multimodal display applications were then reviewed and assessed for their potential in aiding sEVA operations.RESULTS: Through literature review 25 performance impairments were identified. Performance impairments caused by the spacesuit represented the greatest number of sEVA challenges. Multimodal displays were mapped to impairments and approximately 36% of performance impairments could be aided by using display interfaces.DISCUSSION: Multimodal displays may provide additional benefits for alleviating performance impairments during sEVA. Utility of multimodal displays may be greater in certain performance impairment domains, such as spacesuit-related impairments.Zhang JY, Anderson AP. Performance risks during surface extravehicular activity and potential mitigation using multimodal displays. Aerosp Med Hum Perform. 2023; 94(1):34-41.
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Chen X, Yang J, Lv H, Che J, Wang J, Zhang B, Shang P. The potential benefits of melatonin in the prevention and treatment of bone loss in response to microgravity. ACTA ASTRONAUTICA 2023; 202:48-57. [DOI: org/10.1016/j.actaastro.2022.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
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Chen X, Yang J, Lv H, Che J, Wang J, Zhang B, Shang P. The potential benefits of melatonin in the prevention and treatment of bone loss in response to microgravity. ACTA ASTRONAUTICA 2023; 202:48-57. [DOI: 10.1016/j.actaastro.2022.10.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
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Are Skeletal Muscle Changes during Prolonged Space Flights Similar to Those Experienced by Frail and Sarcopenic Older Adults? LIFE (BASEL, SWITZERLAND) 2022; 12:life12122139. [PMID: 36556504 PMCID: PMC9781047 DOI: 10.3390/life12122139] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/13/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Microgravity exposure causes several physiological and psychosocial alterations that challenge astronauts' health during space flight. Notably, many of these changes are mostly related to physical inactivity influencing different functional systems and organ biology, in particular the musculoskeletal system, dramatically resulting in aging-like phenotypes, such as those occurring in older persons on Earth. In this sense, sarcopenia, a syndrome characterized by the loss in muscle mass and strength due to skeletal muscle unloading, is undoubtedly one of the most critical aging-like adverse effects of microgravity and a prevalent problem in the geriatric population, still awaiting effective countermeasures. Therefore, there is an urgent demand to identify clinically relevant biological markers and to underline molecular mechanisms behind these effects that are still poorly understood. From this perspective, a lesson from Geroscience may help tailor interventions to counteract the adverse effects of microgravity. For instance, decades of studies in the field have demonstrated that in the older people, the clinical picture of sarcopenia remarkably overlaps (from a clinical and biological point of view) with that of frailty, primarily when referred to the physical function domain. Based on this premise, here we provide a deeper understanding of the biological mechanisms of sarcopenia and frailty, which in aging are often considered together, and how these converge with those observed in astronauts after space flight.
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Prolonged Exposure to Simulated Microgravity Changes Release of Small Extracellular Vesicle in Breast Cancer Cells. Int J Mol Sci 2022; 23:ijms232416095. [PMID: 36555738 PMCID: PMC9781806 DOI: 10.3390/ijms232416095] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Breast cancer is the leading cause of cancer incidence worldwide and among the five leading causes of cancer mortality. Despite major improvements in early detection and new treatment approaches, the need for better outcomes and quality of life for patients is still high. Extracellular vesicles play an important role in tumor biology, as they are able to transfer information between cells of different origins and locations. Their potential value as biomarkers or for targeted tumor therapy is apparent. In this study, we analyzed the supernatants of MCF-7 breast cancer cells, which were harvested following 5 or 10 days of simulated microgravity on a Random Positioning Machine (RPM). The primary results showed a substantial increase in released vesicles following incubation under simulated microgravity at both time points. The distribution of subpopulations regarding their surface protein expression is also altered; the minimal changes between the time points hint at an early adaption. This is the first step in gaining further insight into the mechanisms of tumor progression, metastasis, the education of the tumor microenvironments, and preparation of the metastatic niche. Additionally, this may lighten up the processes of the rapid cellular adaptions in the organisms of space travelers during spaceflights.
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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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Barkaszi I, Ehmann B, Tölgyesi B, Balázs L, Altbäcker A. Are head-down tilt bedrest studies capturing the true nature of spaceflight-induced cognitive changes? A review. Front Physiol 2022; 13:1008508. [PMID: 36582360 PMCID: PMC9792854 DOI: 10.3389/fphys.2022.1008508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 10/26/2022] [Indexed: 12/15/2022] Open
Abstract
Although a number of studies have examined cognitive functions in space, the reasons behind the observed changes described by space research and anecdotal reports have not yet been elucidated. A potential source of cognitive changes is the cephalad fluid shift in the body caused by the lack of hydrostatic pressure under microgravity. These alterations can be modeled under terrestrial conditions using ground-based studies, such as head-down tilt bedrest (HDBR). In this review, we compare the results of the space and HDBR cognitive research. Results for baseline and in-flight/in-HDBR comparisons, and for baseline and post-flight/post-HDBR comparisons are detailed regarding sensorimotor skills, time estimation, attention, psychomotor speed, memory, executive functions, reasoning, mathematical processing, and cognitive processing of emotional stimuli. Beyond behavioral performance, results regarding brain electrical activity during simulated and real microgravity environments are also discussed. Finally, we highlight the research gaps and suggest future directions.
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Affiliation(s)
- Irén Barkaszi
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
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Vinken M. Hepatology in space: Effects of spaceflight and simulated microgravity on the liver. Liver Int 2022; 42:2599-2606. [PMID: 36183343 DOI: 10.1111/liv.15444] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 09/22/2022] [Accepted: 09/29/2022] [Indexed: 12/13/2022]
Abstract
Microgravity as experienced during spaceflight affects a number of physiological processes in various organs. However, effects on the liver have yet been poorly documented. Nevertheless, the liver is a metabolically highly active organ involved in carbohydrate metabolism, lipid metabolism and xenobiotic biotransformation. The present paper provides an overview of the effects of microgravity on the liver observed in experimental animals during actual spaceflight and upon simulation of microgravity on Earth. These include (i) induction of liver injury and inflammation associated with apoptosis and oxidative stress, (ii) changes in liver carbohydrate metabolism resulting in the onset of a diabetogenic phenotype, (iii) modifications in hepatic lipid metabolism leading to early non-alcoholic fatty liver disease and (iv) alterations of the hepatic xenobiotic biotransformation machinery. Although most of these observations remain to be fully validated in humans, appropriate measures to counteract liver pathogenesis should be considered, especially in view of long-term space missions.
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Affiliation(s)
- Mathieu Vinken
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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