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Rosa-Caldwell ME, Mortreux M, Wadhwa A, Kaiser UB, Sung DM, Bouxsein ML, Rutkove SB. Sex differences in muscle health in simulated micro- and partial-gravity environments in rats. SPORTS MEDICINE AND HEALTH SCIENCE 2023; 5:319-328. [PMID: 38314043 PMCID: PMC10831389 DOI: 10.1016/j.smhs.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 08/22/2023] [Accepted: 09/06/2023] [Indexed: 02/06/2024] Open
Abstract
Skeletal muscle size and strength are important for overall health for astronauts. However, how male and female muscle may respond differently to micro- and partial-gravity environments is not fully understood. The purpose of this study was to determine how biological sex and sex steroid hormones influence the progression of muscle atrophy after long term exposure to micro and partial gravity environments in male and female rats. Male and female Fisher rats (n = 120) underwent either castration/ovariectomy or sham surgeries. After two weeks recovery, animals were divided into microgravity (0g), partial-gravity (40% of weight bearing, 0.4g), or full weight bearing (1g) interventions for 28 days. Measurements of muscle size and strength were evaluated prior to and after interventions. At 0g, females lost more dorsiflexion strength, plantar flexion strength, and other metrics of muscle size compared to males; castration/ovariectomy did not influence these differences. Additionally, at 0.4g, females lost more dorsiflexion strength, plantar flexion strength, and other metrics of muscle strength compared to males; castration/ovariectomy did not influence these differences. Females have greater musculoskeletal aberrations during exposure to both microgravity and partial-gravity environments; these differences are not dependent on the presence of sex steroid hormones. Correspondingly, additional interventions may be necessary to mitigate musculoskeletal loss in female astronauts to protect occupational and overall health.
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Affiliation(s)
- Megan E. Rosa-Caldwell
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA
| | - Marie Mortreux
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA
- Department of Nutrition and Food Sciences, University of Rhode Island, Kingston, RI, 02881, USA
| | - Anna Wadhwa
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA
| | - Ursula B. Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Womenʼs Hospital and Harvard Medical School, Boston, MA, 02215, USA
| | - Dong-Min Sung
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA
| | - Mary L. Bouxsein
- Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Seward B. Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, USA
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Wiggs MP, Lee Y, Shimkus KL, O'Reilly CI, Lima F, Macias BR, Shirazi-Fard Y, Greene ES, Hord JM, Braby LA, Carroll CC, Lawler JM, Bloomfield SA, Fluckey JD. Combined effects of heavy ion exposure and simulated Lunar gravity on skeletal muscle. LIFE SCIENCES IN SPACE RESEARCH 2023; 37:39-49. [PMID: 37087178 DOI: 10.1016/j.lssr.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/04/2023] [Accepted: 02/19/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND The limitations to prolonged spaceflight include unloading-induced atrophy of the musculoskeletal system which may be enhanced by exposure to the space radiation environment. Previous results have concluded that partial gravity, comparable to the Lunar surface, may have detrimental effects on skeletal muscle. However, little is known if these outcomes are exacerbated by exposure to low-dose rate, high-energy radiation common to the space environment. Therefore, the present study sought to determine the impact of highly charge, high-energy (HZE) radiation on skeletal muscle when combined with partial weightbearing to simulate Lunar gravity. We hypothesized that partial unloading would compromise skeletal muscle and these effects would be exacerbated by radiation exposure. METHODS For month old female BALB/cByJ mice were -assigned to one of 2 groups; either full weight bearing (Cage Controls, CC) or partial weight bearing equal to 1/6th bodyweight (G/6). Both groups were then divided to receive either a single whole body absorbed dose of 0.5 Gy of 300 MeV 28Si ions (RAD) or a sham treatment (SHAM). Radiation exposure experiments were performed at the NASA Space Radiation Laboratory (NSRL) located at Brookhaven National Laboratory on Day 0, followed by 21 d of CC or G/6 loading. Muscles of the hind limb were used to measure protein synthesis and other histological measures. RESULTS Twenty-one days of Lunar gravity (G/6) resulted in lower soleus, plantaris, and gastrocnemius muscle mass. Radiation exposure did not further impact muscle mass. 28Si exposure in normal ambulatory animals (RAD+CC) did not impact gastrocnemius muscle mass when compared to SHAM+CC (p>0.05), but did affect the soleus, where mass was higher following radiation compared to SHAM (p<0.05). Mixed gastrocnemius muscle protein synthesis was lower in both unloading groups. Fiber type composition transitioned towards a faster isoform with partial unloading and was not further impacted by radiation. The combined effects of partial loading and radiation partially mitigated fiber cross-sectional area when compared to partial loading alone. Radiation and G/6 reduced the total number of myonuclei per fiber while leading to elevated BrdU content of skeletal muscle. Similarly, unloading and radiation resulted in higher collagen content of muscle when compared to controls, but the effects of combined exposure were not additive. CONCLUSIONS The results of this study confirm that partial weightbearing causes muscle atrophy, in part due to reductions of muscle protein synthesis in the soleus and gastrocnemius as well as reduced peripheral nuclei per fiber. Additionally, we present novel data illustrating 28Si exposure reduced nuclei in muscle fibers despite higher satellite cell fusion, but did not exacerbate muscle atrophy, CSA changes, or collagen content. In conclusion, both partial loading and HZE radiation can negatively impact muscle morphology.
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Affiliation(s)
- Michael P Wiggs
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States; Department of Health, Human Performance and Recreation, Baylor University, Waco, TX, United States.
| | - Yang Lee
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - Kevin L Shimkus
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - Colleen I O'Reilly
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - Florence Lima
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - Brandon R Macias
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States; NASA Johnson Space Center, Houston, Texas, United States
| | - Yasaman Shirazi-Fard
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States; NASA Ames Research Center, Moffett Field, CA, United States
| | - Elizabeth S Greene
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - Jeffrey M Hord
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - Leslie A Braby
- Department of Nuclear Engineering, Texas A&M University, College Station, TX, United States
| | - Chad C Carroll
- Department of Physiology, Purdue University, West Lafayette, IN, United States
| | - John M Lawler
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - Susan A Bloomfield
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
| | - James D Fluckey
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, United States
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Simmons P, Trujillo M, McElroy T, Binz R, Pathak R, Allen AR. Evaluating the effects of low-dose simulated galactic cosmic rays on murine hippocampal-dependent cognitive performance. Front Neurosci 2022; 16:908632. [PMID: 36561122 PMCID: PMC9765097 DOI: 10.3389/fnins.2022.908632] [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: 03/30/2022] [Accepted: 09/12/2022] [Indexed: 12/12/2022] Open
Abstract
Space exploration has advanced substantially over recent decades and plans to increase the duration of deep space missions are in preparation. One of the primary health concerns is potential damage to the central nervous system (CNS), resulting in loss of cognitive abilities and function. The majority of ground-based research on space radiation-induced health risks has been conducted using single particle simulations, which do not effectively model real-world scenarios. Thus, to improve the safety of space missions, we must expand our understanding of the effects of simulated galactic cosmic rays (GCRs) on the CNS. To assess the effects of low-dose GCR, we subjected 6-month-old male BALB/c mice to 50 cGy 5-beam simplified GCR spectrum (1H, 28Si, 4He, 16O, and 56Fe) whole-body irradiation at the NASA Space Radiation Laboratory. Animals were tested for cognitive performance with Y-maze and Morris water maze tests 3 months after irradiation. Irradiated animals had impaired short-term memory and lacked spatial memory retention on day 5 of the probe trial. Glial cell analysis by flow cytometry showed no significant changes in oligodendrocytes, astrocytes, microglia or neural precursor cells (NPC's) between the sham group and GCR group. Bone marrow cytogenetic data showed a significant increase in the frequency of chromosomal aberrations after GCR exposure. Finally, tandem mass tag proteomics identified 3,639 proteins, 113 of which were differentially expressed when comparing sham versus GCR exposure (fold change > 1.5; p < 0.05). Our data suggest exposure to low-dose GCR induces cognitive deficits by impairing short-term memory and spatial memory retention.
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Affiliation(s)
- Pilar Simmons
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Madison Trujillo
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Taylor McElroy
- Department of Aging, University of Florida, Gainesville, FL, United States
| | - Regina Binz
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Rupak Pathak
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Antiño R. Allen
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States,Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States,*Correspondence: Antiño R. Allen,
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Swain P, Mortreux M, Laws JM, Kyriacou H, De Martino E, Winnard A, Caplan N. Skeletal muscle deconditioning during partial weight-bearing in rodents - A systematic review and meta-analysis. LIFE SCIENCES IN SPACE RESEARCH 2022; 34:68-86. [PMID: 35940691 DOI: 10.1016/j.lssr.2022.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/16/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Space agencies are planning to send humans back to the Lunar surface, in preparation for crewed exploration of Mars. However, the effect of hypogravity on human skeletal muscle is largely unknown. A recently established rodent partial weight-bearing model has been employed to mimic various levels of hypogravity loading and may provide valuable insights to better understanding how human muscle might respond to this environment. The aim of this study was to perform a systematic review regarding the effects of partial weight-bearing on the morphology and function of rodent skeletal muscle. Five online databases were searched with the following inclusion criteria: population (rodents), intervention (partial weight-bearing for ≥1 week), control (full weight-bearing), outcome(s) (skeletal muscle morphology/function), and study design (animal intervention). Of the 2,993 studies identified, eight were included. Partial weight-bearing at 20%, 40%, and 70% of full loading caused rapid deconditioning of skeletal muscle morphology and function within the first one to two weeks of exposure. Calf circumference, hindlimb wet muscle mass, myofiber cross-sectional area, front/rear paw grip force, and nerve-stimulated plantarflexion force were reduced typically by medium to very large effects. Higher levels of partial weight-bearing often attenuated deconditioning but failed to entirely prevent it. Species and sex mediated the deconditioning response. Risk of bias was low/unclear for most studies. These findings suggest that there is insufficient stimulus to mitigate muscular deconditioning in hypogravity settings highlighting the need to develop countermeasures for maintaining astronaut/cosmonaut muscular health on the Moon and Mars.
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Affiliation(s)
- Patrick Swain
- Aerospace Medicine and Rehabilitation Laboratory, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom.
| | - Marie Mortreux
- Harvard Medical School, Department of Neurology, Beth Israel Deaconess Medical Center Boston, Massachusetts, United States
| | - Jonathan M Laws
- Aerospace Medicine and Rehabilitation Laboratory, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom
| | - Harry Kyriacou
- School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Enrico De Martino
- Aerospace Medicine and Rehabilitation Laboratory, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom
| | - Andrew Winnard
- Aerospace Medicine and Rehabilitation Laboratory, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom
| | - Nick Caplan
- Aerospace Medicine and Rehabilitation Laboratory, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, United Kingdom
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Mortreux M, Rosa‐Caldwell ME, Stiehl ID, Sung D, Thomas NT, Fry CS, Rutkove SB. Hindlimb suspension in Wistar rats: Sex-based differences in muscle response. Physiol Rep 2021; 9:e15042. [PMID: 34612585 PMCID: PMC8493566 DOI: 10.14814/phy2.15042] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/27/2021] [Accepted: 08/27/2021] [Indexed: 12/16/2022] Open
Abstract
Ground-based animal models have been used extensively to understand the effects of microgravity on various physiological systems. Among them, hindlimb suspension (HLS), developed in 1979 in rats, remains the gold-standard and allows researchers to study the consequences of total unloading of the hind limbs while inducing a cephalic fluid shift. While this model has already brought valuable insights to space biology, few studies have directly compared functional decrements in the muscles of males and females during HLS. We exposed 28 adult Wistar rats (14 males and 14 females) to 14 days of HLS or normal loading (NL) to better assess how sex impacts disuse-induced muscle deconditioning. Females better maintained muscle function during HLS than males, as shown by a more moderate reduction in grip strength at 7 days (males: -37.5 ± 3.1%, females: -22.4 ± 6.5%, compared to baseline), that remains stable during the second week of unloading (males: -53.3 ± 5.7%, females: -22.4 ± 5.5%, compared to day 0) while the males exhibit a steady decrease over time (effect of sex × loading p = 0.0002, effect of sex × time × loading p = 0.0099). This was further supported by analyzing the force production in response to a tetanic stimulus. Further functional analyses using force production were also shown to correspond to sex differences in relative loss of muscle mass and CSA. Moreover, our functional data were supported by histomorphometric analyzes, and we highlighted differences in relative muscle loss and CSA. Specifically, female rats seem to experience a lesser muscle deconditioning during disuse than males thus emphasizing the need for more studies that will assess male and female animals concomitantly to develop tailored, effective countermeasures for all astronauts.
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Affiliation(s)
- Marie Mortreux
- Department of NeurologyHarvard Medical School – Beth Israel Deaconess Medical CenterBostonMassachusettsUSA
| | - Megan E. Rosa‐Caldwell
- Department of NeurologyHarvard Medical School – Beth Israel Deaconess Medical CenterBostonMassachusettsUSA
| | - Ian D. Stiehl
- Department of NeurologyHarvard Medical School – Beth Israel Deaconess Medical CenterBostonMassachusettsUSA
- Department of Physics and AstronomyDartmouth CollegeHanoverNew HampshireUSA
| | - Dong‐Min Sung
- Department of NeurologyHarvard Medical School – Beth Israel Deaconess Medical CenterBostonMassachusettsUSA
| | - Nicholas T. Thomas
- Department of Athletic Training and Clinical NutritionUniversity of KentuckyLexingtonKentuckyUSA
| | - Christopher S. Fry
- Department of Athletic Training and Clinical NutritionUniversity of KentuckyLexingtonKentuckyUSA
| | - Seward B. Rutkove
- Department of NeurologyHarvard Medical School – Beth Israel Deaconess Medical CenterBostonMassachusettsUSA
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Willey JS, Britten RA, Blaber E, Tahimic CG, Chancellor J, Mortreux M, Sanford LD, Kubik AJ, Delp MD, Mao XW. The individual and combined effects of spaceflight radiation and microgravity on biologic systems and functional outcomes. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, TOXICOLOGY AND CARCINOGENESIS 2021; 39:129-179. [PMID: 33902391 PMCID: PMC8274610 DOI: 10.1080/26896583.2021.1885283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Both microgravity and radiation exposure in the spaceflight environment have been identified as hazards to astronaut health and performance. Substantial study has been focused on understanding the biology and risks associated with prolonged exposure to microgravity, and the hazards presented by radiation from galactic cosmic rays (GCR) and solar particle events (SPEs) outside of low earth orbit (LEO). To date, the majority of the ground-based analogues (e.g., rodent or cell culture studies) that investigate the biology of and risks associated with spaceflight hazards will focus on an individual hazard in isolation. However, astronauts will face these challenges simultaneously Combined hazard studies are necessary for understanding the risks astronauts face as they travel outside of LEO, and are also critical for countermeasure development. The focus of this review is to describe biologic and functional outcomes from ground-based analogue models for microgravity and radiation, specifically highlighting the combined effects of radiation and reduced weight-bearing from rodent ground-based tail suspension via hind limb unloading (HLU) and partial weight-bearing (PWB) models, although in vitro and spaceflight results are discussed as appropriate. The review focuses on the skeletal, ocular, central nervous system (CNS), cardiovascular, and stem cells responses.
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Affiliation(s)
| | | | - Elizabeth Blaber
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute
| | | | | | - Marie Mortreux
- Department of Neurology, Harvard Medical School, Beth Israel Deaconess Medical Center
| | - Larry D. Sanford
- Department of Radiation Oncology, Eastern Virginia Medical School
| | - Angela J. Kubik
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute
| | - Michael D. Delp
- Department of Nutrition, Food and Exercise Sciences, Florida State University
| | - Xiao Wen Mao
- Division of Biomedical Engineering Sciences (BMES), Department of Basic Sciences, Loma Linda University
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Approaching Gravity as a Continuum Using the Rat Partial Weight-Bearing Model. Life (Basel) 2020; 10:life10100235. [PMID: 33049988 PMCID: PMC7599661 DOI: 10.3390/life10100235] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/30/2020] [Accepted: 10/03/2020] [Indexed: 12/12/2022] Open
Abstract
For decades, scientists have relied on animals to understand the risks and consequences of space travel. Animals remain key to study the physiological alterations during spaceflight and provide crucial information about microgravity-induced changes. While spaceflights may appear common, they remain costly and, coupled with limited cargo areas, do not allow for large sample sizes onboard. In 1979, a model of hindlimb unloading (HU) was successfully created to mimic microgravity and has been used extensively since its creation. Four decades later, the first model of mouse partial weight-bearing (PWB) was developed, aiming at mimicking partial gravity environments. Return to the Lunar surface for astronauts is now imminent and prompted the need for an animal model closer to human physiology; hence in 2018, our laboratory created a new model of PWB for adult rats. In this review, we will focus on the rat model of PWB, from its conception to the current state of knowledge. Additionally, we will address how this new model, used in conjunction with HU, will help implement new paradigms allowing scientists to anticipate the physiological alterations and needs of astronauts. Finally, we will discuss the outstanding questions and future perspectives in space research and propose potential solutions using the rat PWB model.
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Semple C, Riveros D, Sung DM, Nagy JA, Rutkove SB, Mortreux M. Using Electrical Impedance Myography as a Biomarker of Muscle Deconditioning in Rats Exposed to Micro- and Partial-Gravity Analogs. Front Physiol 2020; 11:557796. [PMID: 33041858 PMCID: PMC7522465 DOI: 10.3389/fphys.2020.557796] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/25/2020] [Indexed: 12/12/2022] Open
Abstract
As astronauts prepare to undertake new extra-terrestrial missions, innovative diagnostic tools are needed to better assess muscle deconditioning during periods of weightlessness and partial gravity. Electrical impedance myography (EIM) has been used to detect muscle deconditioning in rodents exposed to microgravity during spaceflight or using the standard ground-based model of hindlimb unloading via tail suspension (HU). Here, we used EIM to assess muscle changes in animals exposed to two new models: hindlimb suspension using a pelvic harness (HLS) and a partial weight-bearing (PWB) model that mimics partial gravity (including Lunar and Martian gravities). We also used a simple needle array electrode in lieu of surface or ex vivo EIM approaches previously employed. Our HLS results confirmed earlier findings obtained after spaceflight and tail suspension. Indeed, one EIM measure (i.e., phase-slope) that was previously reported as highly sensitive, was significantly decreased after HLS (day 0: 14.60 ± 0.97, day 7: 11.03 ± 0.81, and day 14: 10.13 ± 0.55 | Deg/MHz|, p < 0.0001), and was associated with a significant decrease in muscle grip force. Although EIM parameters such as 50 kHz phase, reactance, and resistance remained variable over 14 days in PWB animals, we identified major PWB-dependent effects at 7 days. Moreover, the data at both 7 and 14 days correlated to previously observed changes in rear paw grip force using the same PWB model. In conclusion, our data suggest that EIM has the potential to serve as biomarker of muscle deconditioning during exposure to both micro- and partial- gravity during future human space exploration.
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Affiliation(s)
- Carson Semple
- Department of Neurology, Harvard Medical School - Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Daniela Riveros
- Department of Neurology, Harvard Medical School - Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Dong-Min Sung
- Department of Neurology, Harvard Medical School - Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Janice A Nagy
- Department of Neurology, Harvard Medical School - Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Seward B Rutkove
- Department of Neurology, Harvard Medical School - Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Marie Mortreux
- Department of Neurology, Harvard Medical School - Beth Israel Deaconess Medical Center, Boston, MA, United States
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