In the Rodent Research Reference Mission (RRRM-2), forty female C57BL/6NTac mice were flown on the International Space Station. To assess differences in outcomes due to age, twenty 12 week-old and twenty 29 week-old mice were flown, respectively. To directly assess spaceflight effects, half of the young and old mice (10 old, 10 young) were sacrificed on-orbit after 55-58 days (ISS Terminal, ISS-T), while the other half (10 old, 10 young) were returned live to Earth after 32 days and allowed to recover for 24 days (Live Animal Return, LAR) before sacrifice. ISS-T and LAR mice were the same age at sacrifice. Both the ISS-T and LAR animals had independent ground controls (10 mice per group housed in flight hardware in matched environmental conditions), basal controls (10 mice per group sacrificed 2 days before launch), and vivarium controls (10 mice per group housed within standard vivarium habitats). Thus RRRM-2 included a total of 160 mice. This study includes single cell transcriptional profiling data from humerus bone marrow from 4 young LAR flight animals, 4 old LAR flight animals, 4 young LAR ground control animals, and 4 old LAR ground control animals.

Spaceflight is known to affect immune cell populations. In particular, splenic B-cell numbers decrease during spaceflight and in ground-based physiological models. Although antibody isotype changes have been assessed during and after spaceflight, an extensive characterization of the impact of spaceflight on antibody composition has not been conducted in mice. Next Generation Sequencing and bioinformatic tools are now available to assess antibody repertoires. We can now identify immunoglobulin gene- segment usage, junctional regions, and modifications that contribute to specificity and diversity. Due to limitations on the International Space Station, alternate sample collection and storage methods must be employed. Our group compared Illumina MiSeq sequencing data from multiple sample preparation methods in normal C57Bl/6J mice to validate that sample preparation and storage would not bias the outcome of antibody repertoire characterization. In this report, we also compared sequencing techniques and a bioinformatic workflow on the data output when we assessed the IgH and Igκ variable gene usage. Our bioinformatic workflow has been optimized for Illumina HiSeq and MiSeq datasets, and is designed specifically to reduce bias, capture the most information from Ig sequences, and produce a data set that provides other data mining options.

To understand how humans adapt to space environments many experiments can be conducted on astronauts while they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the physical issues we face in space travel. The medaka is a suitable model fish for studying space adaptation because in the second International Microgravity Laboratory mission in 1994 adult fish mated successfully in space during 15 days of flight. In 2012 another space experiment Medaka Osteoclast was performed. Male and female fish (6 weeks old at launching) were maintained in the Aquatic Habitat system for 2 months in the ISS. The RNA-seq analysis of tissues from these fish will revealed tissue-specific responsiveness and common stress responses during space adaptation.

Changes in gene expression profiles implicated in oxidative stress and in ECM remodeling in mouse skin were examined after space flight. The metabolic effects of space flight in skin tissues were also characterized.

The objective of the Rodent Research-10 Mission (RR-10) was to investigate how spaceflight affects the cellular and molecular mechanisms of normal bone tissue regeneration in space. To this end, ten (10) 14-15 weeks-old female B6129SF2/J Wild Type (WT), and ten (10) 14-15 weeks-old female B6;129S2-Cdkn1atm1Tyj/J (p21-null) mice received a pre-flight subcutaneous injection of the bone marker (Alizarin Red), and were then delivered to the ISS aboard SpaceX-21. At 7 days before euthanasia, all 20 mice received an intraperitoneal (IP) injection with a bone formation marker (Calcein). At 48 +/- 2 hours before euthanasia, all 20 mice received an IP injection with a second dose of Calcein as well as a cell proliferation marker (BrdU). Then, following 28-29 days in microgravity, the Flight mice were euthanized. Following removal of hindlimbs, carcasses were wrapped in aluminum foil, preserved in the CryoChiller, and stored at -80 C or colder until return to Earth. In addition to the Flight group, three ground control groups were also part of the study: Basal (representing the pre-launch state), Vivarium (standard vivarium housing for the same duration of time as flight), and Ground (flight habitat in the International Space Station Environment Simulator, ISSES). Twenty mice (10 of each strain) were included in each of these control groups (except Vivarium which included 12 of each strain). These were treated, euthanized and processed on the same schedule and in the same manner as the flight samples. At the end of RR-10 experiment, all frozen carcasses were partially thawed and fecal pellets were removed and preserved by flash freezing in LN2. DNA was extracted, shotgun metagenome libraries generated, and libraries sequenced (target 10 M clusters at PE 250 bp). This dataset features WT samples from the Flight (n=3), Ground (n=5), Basal (n=10) and Vivarium groups (n=12), as well as p21-null samples from Flight (n=5), Ground (n=5), Basal (n=10) and Vivarium groups (n=12).

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.

The objective of the Rodent Research-7 mission (RR-7) was to study the impact of the space environment on the gut microbiota of two strains of mice and how any changes in-turn affect the immune system, metabolic system, and circadian or daily rhythms. To this end, ten 11-week-old female C57BL/6J and ten 11-week-old female C3H/HeJ mice were flown to the International Space Station on June 29, 2018 on SpaceX-15 and housed in two Rodent Habitats. Samples of food, swabs from living surfaces, and fecal pellets were collected from each animal before launch and regularly during the mission. The mission also involved extended video collection (48 hr video segments per Habitat) to monitor circadian rhythms, and on-orbit mass measurement. After 25 days on-orbit, half of the mice of each strain were euthanized on the ISS with Ketamine/Xylazine/Acepromazine and cardiac puncture, after which carcasses were segmented in three sections and preserved in RNA later. After 75-76 days the remaining 5 animals from each group were euthanized and processed in the same manner. The 25-day dissected carcasses returned on SpX-15, and the 75-day dissected carcasses returned on SpX-16. In addition to the Flight group, three ground control groups were also part of the study: Basal (representing the pre-launch state), Vivarium (standard vivarium housing for the same duration of time as flight), and Ground (same habitat in the International Space Station Environment Simulator, ISSES). Twenty mice (10 of each strain) were included in each of these control groups, which were euthanized and processed on the same schedule and in the same manner as the flight samples. Dissections for tissues from all experimental groups were completed by the PI groups along with NASA's Biospecimen Sharing Program in February 2019. GeneLab received dorsal skin samples from forty C57BL/6J mice: 10 Basal, 5 Ground (25 days), 5 Ground (75 days), 5 Flight (25 days), 5 Flight (75 days), 5 Vivarium (25 days), 5 Vivarium (75 days). GeneLab received dorsal skin samples from forty C3H/HeJ mice: 10 Basal, 5 Ground (25 days), 5 Ground (75 days), 5 Flight (25 days), 5 Flight (75 days), 5 Vivarium (25 days), 5 Vivarium (75 days). From these skin samples, RNA was extracted, libraries generated (stranded, ribodepleted) and sequenced (target 60 M clusters at PE 98 bp).

Spaceflight has been shown to suppress the adaptive immune response, altering the distribution and function of lymphocyte populations. B lymphocytes express highly specific and highly diversified receptors, known as immunoglobulins (Ig), that directly bind and neutralize pathogens. Ig diversity is achieved through the enzymatic splicing of gene segments within the genomic DNA of each B cell in a host. The collection of Ig specificities within a host, or Ig repertoire, has been increasingly characterized in both basic research and clinical settings using high-throughput sequencing technology (HTS). We utilized HTS to test the hypothesis that spaceflight affects the B-cell repertoire. To test this hypothesis, we characterized the impact of spaceflight on the unimmunized Ig repertoire of C57BL/6 mice that were flown aboard the International Space Station (ISS) during the Rodent Research One validation flight in comparison to ground controls. Individual gene segment usage was similar between ground control and flight animals, however, gene segment combinations and the junctions in which gene segments combine was varied among animals within and between treatment groups. We also found that spontaneous somatic mutations in the IgH and Igκ gene loci were not increased. These data suggest that space flight did not affect the B cell repertoire of mice flown and housed on the ISS over a short period of time.

Changes in gene expression profiles implicated in oxidative stress and in ECM remodeling in mouse skin were examined after space flight. The metabolic effects of space flight in skin tissues were also characterized.

Space exploration exposes astronauts to stressors that alter the immune response, rendering them vulnerable to infections and diseases. In this study, we aimed to determine the levels of inflammasome activation in the brains of mice that were housed in the International Space Station (ISS) for 37 days. C57BL/6 mice were launched to the ISS as part of NASA’s Rodent Research 1 Mission on SpaceX-4 CRS-4 Dragon cargo spacecraft from September 21st, 2014, to October 25th, 2014. Dissected mouse brains from that mission were analyzed by immunoblotting of inflammasome signaling proteins and Electrochemiluminescence Immunoassay (ECLIA) for inflammatory cytokine levels. Our data indicate decreased inflammasome activation in the brains of mice that were housed in the ISS for 37 days when compared to the brains of mice that were maintained on the ground, and in mice corresponding to the baseline group that were sacrificed at the time of launching of SpaceX-4. Moreover, we did not detect any significant changes in the expression levels of the pro-inflammatory cytokines TNF-alpha, IL-2, IFN-gamma, IL-5, IL-6, IL-12p70 and IL-10 between the ground control and the flight groups. Together, these studies suggest that spaceflight results in a decrease in the levels of innate immune signaling molecules that govern inflammasome signaling in the brain of mice. This dataset derives results from the ECLIA and Western Blot assays using brain tissue.