This study tested the hypothesis that transcription of immediate early genes is inhibited in T cells activated in microgravity (uG). Immunosuppression during spaceflight is a major barrier to safe long-term human space habitation and travel. The goals of these experiments were to prove that uG was the cause of impaired T cell activation during spaceflight as well as understand the mechanisms controlling early T cell activation. T cells from 4 human donors were stimulated with concanavalin A (ConA) and anti-CD28 onboard the International Space Station (ISS). An onboard centrifuge was used to generate a 1g simultaneous control to isolate the effects of uG from other variables of spaceflight. Microarray expression analysis after 1.5 hours of activation demonstrated that mg- and 1g-activated T cells had distinct patterns of global gene expression and identified 47 genes that were significantly differentially down-regulated in uG. Importantly, several key immediate early genes were inhibited in uG. T cells were isolated from human volunteers. T cells from each donor were kept separate and loaded into individual chambers in separate cassettes for the following treatments: uG non-activated, uG activated, and 1g activated. Therefore, samples represent biological triplicates. Experimental units were launched into space and placed into the KUBIK facility onboard the International Space Station. The 1g units were placed in the central centrifuge positions and centrifuged with an applied 1g force. The uG units were place in the static positions for continued uG exposure. After 30 minutes of pre-incubation, uG non-activated units were fixed by addition of RNALater (QIAGEN, Valencia, CA), removed from the incubator, and stored in 4°C. The uG and 1g activated units were injected with final concentration 10mg/ml Con A and 4mg/ml anti-CD28. These cassettes were replaced into KUBIK on either the centrifuge or static positions and activated for 1.5 hours. Activation was stopped with the addition of RNALater and the units were then moved to 4°C storage. All units were returned to Earth for analysis.

Physical forces greatly influence the growth and function of an organism. Altered gravity can perturb normal development and induce corresponding changes in gene expression. Understanding this relationship between the physical and biological realms is important for NASA s space travel goals. We use combined RNA-Seq and qRT-PCR to profile changes in early Drosophila melanogaster pupae exposed to chronic hypergravity (3 g three times Earth s gravity) to highlight gravity-dependent pathways and gene products. Robust transcriptional response was evident among the pupae developed in a hypergravity environment compared to control. 1,513 genes showed significantly (p < 0.05) altered gene expression in the 3 g samples. These findings were supported with qRT-PCR data. Major biological processes affected include ion transport redox homeostasis immune and humoral stress response proteolysis and cuticle development.

The spaceflight experiment was carried out using male C57BL/10J mice (8 weeks old at launch). Wild type mice (n=3) were launched by Space Shuttle Discovery and housed on the International Space Station (ISS) for 91 days. They returned to the Earth by Space Shuttle Atlantis. But only one mouse returned to the Earth alive. Whole brain was sampled from the mouse killed by inhalation of carbon dioxide at the Life Sciences Support Facility of Kennedy Space Center within 3-4 hours after landing. After the spaceflight experiment the on-ground experiment was also carried out at the Advanced Biotechnology Center in Genova Italy. A mouse with the same species sex and age was housed in mice drawer system (MDS) which was utilized for the spaceflight (SF) mice for 3 months as the ground control (GC). Another mouse was housed in normal vivarium cage as the laboratory control (LC). Amount of food and water supplementation and environmental conditions were simulated as the flight group. After 3 months brain was sampled from one mouse in group GC and LC respectively. Comprehensive analyses of gene expression were performed in the right brain. Total of 4,000 genes were analyzed. The expression levels of 60 genes significantly changed in response to SF compared with LC and/or GC. The 15 and 16 genes were up- (> 2 folds) and down-regulated (< 0.5 folds) respectively following SF vs. GC. The levels of 58 genes were significantly altered by housing in MDS in space and/or on the ground. Forty seven and 11 genes were significantly up- and down-regulated vs. LC. Twenty seven out of these genes responded to caging in MDS both in space and on the ground. Further 31 genes were influenced by housing in MDS on the Earth. Responses of the characteristics of brain to long-term gravitational unloading were investigated in mice.

Physical forces greatly influence the growth and function of an organism. Altered gravity can perturb normal development and induce corresponding changes in gene expression. Understanding this relationship between the physical and biological realms is important for NASA s space travel goals. We use combined RNA-Seq and qRT-PCR to profile changes in early Drosophila melanogaster pupae exposed to chronic hypergravity (3 g three times Earth s gravity) to highlight gravity-dependent pathways and gene products. Robust transcriptional response was evident among the pupae developed in a hypergravity environment compared to control. 1,513 genes showed significantly (p < 0.05) altered gene expression in the 3 g samples. These findings were supported with qRT-PCR data. Major biological processes affected include ion transport redox homeostasis immune and humoral stress response proteolysis and cuticle development.

Astronauts are exposed to a unique combination of stressors during spaceflight which leads to alterations in their physiology and potentially increases their susceptibility to infectious pathogens. Here we report the first microarray evaluation of any astronaut tissue sample specifically whole blood before and after spaceflight using an array comprising 234 well-characterized stress response genes. Differentially regulated genes included those important for DNA repair oxidative stress and protein folding/degradation. Microarrays comprising 234 well characterized stress-related genes were used to profile transcriptomic changes in six astronauts before and after short-duration spaceflight. Blood samples were collected for analysis from each eastronaut 10 days prior and 2-3 hours after return from spaceflight. Data submitted for platform GPL140 contain genes that have been pre-filtered by the analytical software to remove values of low certainty resulting in missing values for some samples. Unfortunately these original data are no longer available due to physical damage at Tulane University during hurricane Katrina but the processed values were retained in redundant locations and these are submitted for upload to GEO.

Spaceflight results in a number of adaptations to skeletal muscle including atrophy and shifts towards faster muscle fiber types. To identify changes in gene expression that may underlie these adaptations microarray expression analysis was performed on gastrocnemius from mice flown on the STS-108 shuttle flight (11 days 19 hours) versus mice maintained on earth for the same period. Additionally to identify changes that were due to unloading and reloading microarray analyses were conducted on calf muscle from ground-based mice subjected to hindlimb suspension (12 days) and mice subjected to hindlimb suspension plus a brief period of reloading (3.5 hours) to simulate the time between landing and sacrifice of the spaceflight mice.

Gene expression levels were determined in 3rd instar and adult Drosophila melanogaster reared during spaceflight to elucidate the genetic and molecular mechanisms underpinning the effects of microgravity on the immune system. The goal was to validate the Drosophila model for understanding alterations of innate immune responses in humans due to spaceflight. Five containers of flies with ten female and five male fruit flies in each container were housed and bred on the space shuttle (average orbit altitude of 330.35 km) for 12 days and 18.5 hours with a new generation reared in microgravity. RNA was extracted on the day of shuttle landing from whole body animals (3rd instar larvae and adults) hybridized to Drosophila 2.0 Affymetrix genome arrays and the expression level of all genes was normalized against the gene expression level from the corresponding developmental stage animals raised on ground. Spaceflight altered the expression of larval genes involved in the maturation of plasmatocytes (macrophages) and their phagocytic response as well as the level of constitutive expression of pattern recognition receptors and opsonins that specifically recognize bacteria and of lysozymes antimicrobial peptide pathway and immune stress genes hallmarks of humoral immunity. Larval microarrays (FL 6 samples) are based on RNA extracted from 6 independent sets of 50 mid 3rd instar larvae reared in microgravity and collected on the day of landing after 12 days and 18.5 hours on the space shuttle and the same number of control larvae raised on ground (GL 6 samples). Adults microarrays (F1 3 samples) are based on RNA from 3 sets of 20 adult females each that emerged during spaceflight and within 4 hours of landing and the same number of adult females from the corresponding ground control containers (G1 3 samples).

The thymus undergoes atrophy during spaceflight. In this study we analyzed gene expression of the thymus of mice on board International space station to elucidate molecular aspects of the thymic atrophy by spaceflight.

In this study transcriptome profiling was used to gain insight into the spaceflight adaptation role of Altered response to gravity-1 (Arg1) a gene known to affect gravity responses in plants on Earth. The study compared expression profiles of cultured lines of Arabidopsis thaliana derived from wild type (WT) cultivar Col-0 to profiles from a knock-out line deficient in the gene encoding (ARG1 KO) both on the ground and in space. The cell lines were launched on SpaceX CRS-2 as part of the Cellular Expression Logic (CEL) experiment of the BRIC17 spaceflight mission. The cultured cell lines were grown within 60mm Petri plates in Petri Dish Fixation Units (PDFUs) that were housed within the Biological Research In Canisters (BRIC) hardware. Spaceflight samples were fixed on orbit. Differentially expressed genes were identified between the two environments (spaceflight and comparable ground controls) and the two genotypes (WT and ARG1 KO). Each genotype engaged unique genes during physiological adaptation to the spaceflight environment with little overlap. Most of the genes altered in expression in spaceflight in WT cells were found to be Arg1-dependent suggesting a major role for that gene in the physiological adaptation of undifferentiated cells to spaceflight.

Genome-wide transcriptional profiling shows that reducing gravity levels in the International Space Station (ISS) causes important alterations in Drosophila gene expression. However simulation experiments on ground without space constraints show weaker effects than space environment. A global and integrative analysis using the gene expression dynamics inspector (GEDI) self-organizing maps reveals a subtle response of the transcriptome using different populations and microgravity and hypergravity simulation devices. These results suggest that in addition to behavioural responses that can be detected also at the gene expression level the transcriptome is finely tuned to normal gravity. The alteration of this constant parameter on Earth can have effects on gene expression that depends both on the environmental conditions and the ground based facility used to compensate the gravity vector. Alternative and commons effects of mechanical facilities like the Random Positioning Machine and a centrifuge and strong magnetic field ones like a cryogenically cooled superconductive magnet are discussed. We compare the effects over the gene expression profile of different gender/age Drosophila imagoes in 3-4 days-long experiments under altered gravity conditions into three GBF (Ground Based Facilities for micro/hyper- gravity simulation) using whole genome microarray platforms. Descriptions of different GBFs (treatments): LDC means Large Diameter Centrifuge. Samples can be placed under three conditions: inside LDC (at certain g level) at the LDC rotational control and at external 1g control (outside the LDC). RPM means Random Positioning Machine. Samples can be placed under two conditions: inside RPM (at nearly 0g Microgravity level) and at external 1g control (outside the RPM). At the magnet means INSIDE the Magnetic levitator (another GBF). Samples can be placed under four conditions: inside Magnet 0g* (at microgravity with magnetic field) inside Magnet at 1g* (internal control with magnetic field) or inside the magnet 2g* (at hypergravity with magnetic field) and at external 1g control (outside the magnet)