It is well established that microgravity exposure causes significant muscle weakness and atrophy via muscle unloading. On Earth, muscle unloading leads to a disproportionate loss in muscle force and size with the loss in muscle force occurring at a faster rate. Although the exact mechanisms are unknown, a role for Ca2+ dysregulation has been suggested. The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) pump actively brings cytosolic Ca2+ into the SR, eliciting muscle relaxation and maintaining low intracellular Ca2+ ([Ca2+]i). SERCA dysfunction contributes to elevations in [Ca2+]i, leading to cellular damage, and may contribute to the muscle weakness and atrophy observed with spaceflight. Here, we investigated SERCA function, SERCA regulatory protein content, and reactive oxygen/nitrogen species (RONS) protein adduction in murine skeletal muscle after 35-37 days of spaceflight. In male and female soleus muscles, spaceflight led to drastic impairments in Ca2+ uptake despite significant increases in SERCA1a protein content. We attribute this impairment to an increase in RONS production and elevated total protein tyrosine (T) nitration and cysteine (S) nitrosylation. Contrarily, in the tibialis anterior (TA), we observed an enhancement in Ca2+ uptake, which we attribute to a shift towards a faster muscle fiber type (i.e., increased myosin heavy chain IIb and SERCA1a) without elevated total protein T-nitration and S-nitrosylation. Thus, spaceflight affects SERCA function differently between the soleus and TA. This dataset derives results from the calcium uptake (spectrofluorometry) and Western blot assays.

Spaceflight imposes the risk of skeletal muscle atrophy for astronauts. The understanding of muscle atrophy because of spaceflight is limited but continued efforts are essential for developing countermeasures of this effect. A distinct difference between spaceflight-induced muscle atrophy and other forms of atrophy is the additional effect of cosmic rays in outer space. To study spaceflight-induced muscle atrophy we performed two ground-based models of microgravity in a low dose radiation environment and studied transcriptional changes in rat soleus muscle using microarray technology.

Microgravity exposure as well as chronic muscle disuse are two of the main causes of physiological adaptive skeletal muscle atrophy in humans and murine animals in physiological condition. The aim of this study was to investigate at both morphological and global gene expression level skeletal muscle adaptation to microgravity in mouse soleus and extensor digitorum longus (EDL). Adult male mice C57BL/N6 were flown aboard the BION-M1 biosatellite for 30 days on orbit (BF) or housed in a replicate flight habitat on Earth (BG) as reference flight control. In this study we investigated for the first time gene expression adaptation to 30 days of microgravity exposure in mouse soleus and EDL highlighting potential new targets for improvement of countermeasures able to ameliorate or even prevent microgravity-induced atrophy in future spaceflights. Overall Design: C57BL/N6 mice were randomly divided in 3 groups: Bion Flown (BF) mice flown aboard the Bion M1 biosatellite in microgravity environment for 30 days; Bion Ground (BG) mice housed in the same habitat of flown animals but exposed to earth gravity; and Flight Control (FC) mice housed in a standard animal facility.

Microgravity exposure as well as chronic muscle disuse are two of the main causes of physiological adaptive skeletal muscle atrophy in humans and murine animals in physiological condition. The aim of this study was to investigate at both morphological and global gene expression level skeletal muscle adaptation to microgravity in mouse soleus and extensor digitorum longus (EDL). Adult male mice C57BL/N6 were flown aboard the BION-M1 biosatellite for 30 days on orbit (BF) or housed in a replicate flight habitat on Earth (BG) as reference flight control. In this study we investigated for the first time gene expression adaptation to 30 days of microgravity exposure in mouse soleus and EDL highlighting potential new targets for improvement of countermeasures able to ameliorate or even prevent microgravity-induced atrophy in future spaceflights. Overall Design: C57BL/N6 mice were randomly divided in 3 groups: Bion Flown (BF) mice flown aboard the Bion M1 biosatellite in microgravity environment for 30 days; Bion Ground (BG) mice housed in the same habitat of flown animals but exposed to earth gravity; and Flight Control (FC) mice housed in a standard animal facility.

The long-term adaptations to microgravity and other spaceflight challenges within the confines of a spacecraft, and readaptations to weight-bearing upon reaching a destination, are unclear. While post-flight gait change in astronauts have been well documented and reflect multi-system deficits, no data from rodents have been collected. Thus, the purpose of this study was to evaluate gait changes in response to spaceflight. A prospective collection of gait data was collected on 3 groups of mice: those who spent~35 days in orbit (FLIGHT) aboard the International Space Station (ISS); a ground-based control with the same habitat conditions as ISS (Ground Control; GC); and a vivarium control with typical rodent housing conditions (VIV). Pre-flight and post-flight gait measurements were conducted utilizing an optimized and portable gait analysis system (DigiGait, Mouse Specifics, Inc). The total data acquisition time for gait patterns of FLIGHT and control mice was 1.5–5 min/mouse, allowing all 20 mice per group to be assessed in less than an hour. Patterns of longitudinal gait changes were observed in the hind limbs and the forelimbs of the FLIGHT mice after ~35 days in orbit; few differences were observed in gait characteristics within the GC and VIV controls from the initial to the final gait assessment, and between groups. For FLIGHT mice, 12 out of 18 of the evaluated gait characteristics in the hind limbs were significantly changed, including: stride width variability; stride length and variance; stride, swing, and stance duration; paw angle and area at peak stance; and step angle, among others. Gait characteristics that decreased included stride frequency, and others. Moreover, numerous forelimb gait characteristics in the FLIGHT mice were changed at post-flight measures relative to pre-flight. This rapid DigiGait gait measurement tool and customized spaceflight protocol is useful for providing preliminary insight into how spaceflight could affect multiple systems in rodents in which deficits are reflected by altered gait characteristics. This dataset derives results from the behavior (gait) assay.

Bone loss and immune dysregulation are among the main adverse outcomes of spaceflight challenging astronaut xe2 x80 x99s health and safety. However consequences on B cell development and responses are still under-investigated. Up to now most studies addressing these questions were performed using an amphibian species. Consequently we used advanced proteomics analysis of femur bone and marrow of mice flown for one month on board the BION-M1 biosatellite to determine whether extreme conditions encountered during a real spaceflight affect B cell development in mice and to examine reversibility of the effects upon return to Earth. Our data revealed that adverse effects on B lymphopoiesis were more marked one week after landing and that this phenomenon was associated with a 41% reduction of B cells in the spleen. Thus the effects of spaceflight persisted during at least one week after landing. These reductions may contribute to explain increased susceptibility to infection even if we confirmed that animals were able to mount a humoral immune response.

Upon weightlessness and microgravity deleterious effects on the neurosensory and neurovestibular systems haematological changes and deconditioning of musculoskeletal cardiovascular and cardiopulmonary functions have been reported. In particular loss of muscle mass and strength are triggered by weightlessness in humans during space flights that is similarly observed as a result of physical inactivity conditions and aging on Earth. However skeletal muscle tissue is of paramount importance for health maintenance (e.g. being essential to locomotion heat production and metabolism). To better prevent or eventually treat microgravity-induced muscle atrophy its underlying mechanisms have first to be characterized in detail. Using cutting-edge quantitative proteomics the aim of the present study was therefore to get an in depth view of the molecular regulations triggered by space conditions in skeletal muscles of mice during the 30-day flight of the BION-M1 biosatellite. As muscles differing in their fiber type composition appear to respond differently to microgravity (see above) we characterized here the differential response of the soleus extensor digitorum longus and vastus lateralis muscles.

With technological advancements, human's desire to explore space is growing and more people are staying longer at the international space station (ISS). The impact of microgravity on stem cells (SC) is not fully understood. We explored the impact of microgravity on gene expression profile of cultured mesenchymal stem/stromal cells (MSCs) at the ISS. We also evaluated how the new knowledge gained sheds light on our understanding of human physiology on Earth. Primary cultures of MSCs were expanded at the ISS for 1 or 2 weeks and mRNA was isolated from samples of the cultured cells. Gene expression profiles were determined and compared with samples from real-time ground control cultures. Differential gene expression, gene set enrichment analysis and determination of key genes were performed that revealed for the first time the existence of potential 'master regulators' coordinating a systemic response to microgravity. Cyclin D1 (CCND1), a protein-coding gene that regulates cell cycle progression and CDK kinases, was identified as the most connected regulator at week 1. Further analysis showed the impacted genes from cultured MSCs significantly correlated with known gene pathways associated with cell division, chromosomal segregation and nuclear division, extracellular matrix structure and organization, muscle apoptosis and differentiation. This study exemplifies the utility of space research to advance our understanding of human physiology both on Earth and in space. To investigate the effects of microgravity on MSC growth and understand the differences in gene expression profiles between microgravity and ground control environments, two groups of MSC were sent to the ISS. One group was cultured for one week, while the other was cultured for two weeks, with corresponding control groups processed similarly on Earth. The cells were then preserved and transferred back to the laboratory. Further Gene expression profiles were compared between samples to identify differentially expressed genes.

Spaceflight is a unique environment with profound effects on biological systems including tissue redistribution and musculoskeletal stresses. However the more subtle biological effects of spaceflight on cells and organisms are difficult to measure in a systematic unbiased manner. Here we test the utility of the molecularly barcoded yeast deletion collection to provide a quantitative assessment of the effects of microgravity on a model organism. We developed robust hardware to screen in parallel the complete collection of ~4800 homozygous and ~5900 heterozygous (including ~1100 single-copy deletions of essential genes) yeast deletion strains each carrying unique DNA that acts as strain identifiers. We compared strain fitness for the homozygous and heterozygous yeast deletion collections grown in spaceflight and ground as well as plus and minus hyperosmolar sodium chloride providing a second additive stressor. The genome-wide sensitivity profiles obtained from these treatments were then queried for their similarity to a compendium of drugs whose effects on the yeast collection have been previously reported. We found that the effects of spaceflight have high concordance with the effects of DNA-damaging agents and changes in redox state suggesting mechanisms by which spaceflight may negatively affect cell fitness.

Spaceflight is a unique environment with profound effects on biological systems including tissue redistribution and musculoskeletal stresses. However the more subtle biological effects of spaceflight on cells and organisms are difficult to measure in a systematic unbiased manner. Here we test the utility of the molecularly barcoded yeast deletion collection to provide a quantitative assessment of the effects of microgravity on a model organism. We developed robust hardware to screen in parallel the complete collection of ~4800 homozygous and ~5900 heterozygous (including ~1100 single-copy deletions of essential genes) yeast deletion strains each carrying unique DNA that acts as strain identifiers. We compared strain fitness for the homozygous and heterozygous yeast deletion collections grown in spaceflight and ground as well as plus and minus hyperosmolar sodium chloride providing a second additive stressor. The genome-wide sensitivity profiles obtained from these treatments were then queried for their similarity to a compendium of drugs whose effects on the yeast collection have been previously reported. We found that the effects of spaceflight have high concordance with the effects of DNA-damaging agents and changes in redox state suggesting mechanisms by which spaceflight may negatively affect cell fitness.