Microgravity effect on C. elegans gene expression was analysed by whole genome microarray. The worms were cultivated under microgravity for 4 days in the Japanese Module of the International Space Station. C. elegans N2 was exposed microgravity for 4 days. The worms synchronously were cultivated from L1 larvae to adult. There are two control groups onboard 1G and ground 1G control.

We used microarrays to investigate the effects of microgravity and space radiation on the genome-wide expression of the C. elegans. Three technical replicates of wild type C. elegans (CC1 strain) which exposed to space radiation are analyzed along with ground control.

The effect of microgravity on gene expression in C.elegans was comprehensively analysed by DNA microarray. This is the first DNA microarray analysis for C.elegans grown under microgravity. Hyper gravity and clinorotation experiments were performed as reference against the flight experiment.

The goal of this study was to assess whether low shear-modeled microgravity (LSMMG) affects yeast genomic expression patterns using the powerful tool of whole genome microarray hybridization. We determined changes in the yeast model organism, Saccharomyces cerevisisae, when grown in LSMMG using the rotating High Aspect Ratio Vessel (HARV). A significant number of genes were up- or down-regulated by at least two fold in cells that were grown for 5 generations or 25 generations in HARVs. We identified genes in cell wall integrity signaling pathways containing MAP kinase cascades that may provide clues to novel physiological responses of eukaryotic cells to the external stress of a low-shear modeled microgravity environment. A comparison of the microgravity response to other environmental stress response (ESR) genes showed that 26% of the genes that respond ,significantly to LSMMG are involved in a general environmental stress response, while 74% of the genes may represent a unique transcriptional response to microgravity. In addition, we found changes in genes involved in budding, cell polarity establishment, and cell separation that confirm our hypothesis that exposure to LSMMG causes changes in gene transcription resulting in a phenotypic response. The results of the study provide interesting clues to potential mechanisms involved in the response to, adaptation to, and survival of eukaryotic cells in a microgravity environment and our findings may have important health implications for human spaceflight. Experiment Overall Design: Four conditions are compared with three replicates each: yeast grown in low-shear modeled microgravity (HARV bioreactor) for 5 and 25 generations; yeast grown in a horizontal (non-LSMMG) HARV bioreactor for 5 and 25 generations.

Cell cycle and cell proliferation are decoupled under altered gravity conditions. We have previously shown that semisolid cell cultures of Arabidopsis suffer overall genome changes in response to altered gravity and also that cell cycle stages duration is altered. By using synchronized cell cultures we will demonstrate the precise alterations in cell cycle duration and also the transcriptional signature in any of them. Experiments consists on exposures of Arabidopsis cell cultures to 1g control/simulated microgravity (RPM) conditions. Asynchronous cells exposed for 14 h + Syncronous populations choosen to have an enrichment of cell cycle phases were used (being T7/T10 samples on G2 phase T14/T16 samples on G1 phase). 6 dye-swap - time course treated vs untreated comparison.

Microgravity leads to a 10-15% loss of bone mass in astronauts during space flight. Osteoclast is the multinucleated bone resorbing cell. In this study we used NASA developed ground based Rotary Wall Vessel Bioreactor (RWV) Rotary Cell Culture System (RCCS) to simulate microgravity (uXg) conditions and demonstrated a significant increase (2-fold) in osteoclastogenesis compared to ground based control (Xg) mouse bone marrow cultures. We further determined the gene expression profiling of RAW 264.7 osteoclast progenitor cells in microgravity by agilent microarray analysis. Gene expression pattern was functional group clustered by transcriptome analysis using gene ontology tree machine (GOTM) for cell proliferation/survival differentiation and function. We confirm the microgravity modulated gene expression critical for osteoclast differentiation by real-time RT-PCR and Western blot analysis in murine bone marrow cultures. We identify transcription factors such as c-Jun c-Fos PU-1 critical for osteoclast differentiation is up-regulated in microgravity conditions. In addition microgravity resulted in 2.3 and 2.0-fold increase in the level of cathepsin K and MMP-9 matrix metalloproteinase expression in preosteoclast cells involved in the bone resorption process respectively. We also demonstrate a significant increase in the expression levels of M-CSF receptor c-Fms and PLCy2 and S100A8 molecules that play an important role in Ca2+ signaling essential for osteoclast function. Further microgravity stimulated preosteoclast cells showed elevated cytosolic Ca2+ levels compared to ground based control cells. Thus microgravity regulated gene expression profiling in preosteoclast cells provide new insights in to molecular mechanisms and therapeutic targets of osteoclast differentiation/activation responsible for bone loss and fracture risk in astronauts during space flight mission. Microgravity associated with space flight is a challenge for normal bone homeostasis. Astronauts experience 10-15% bone loss during a space flight mission. We aimed to determine the effect of simulated microgravity on osteoclast preosteoclasts cells. RAW264.7 cells (1.5 x 106 /ml) were loaded in RCCS with DMEM containing 10% FBS for 24 h. The cells were stimulated with RANKL (80ng/ml) for 24 h to obtain preosteoclasts in parallel with ground based control cells. Total RNA was isolated using RNAzol reagent (Biotecx Labs Houston TX) from control (Xg) and microgravity (uXg) subjected cells and hybridized with Agilent whole mouse genome 4x44K array system. Slides were washed and scanned on an Agilent G2565 microarray scanner. Data obtained were analyzed with Agilent feature extraction and GeneSpring GX v7.3.1 software packages (Genus biosystem Inc. Northbrook IL USA).

This study tested the hypothesis that transcription of immediate early genes is inhibited in T cells activated in microgravity (mg). 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 mg 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 mg 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 mg. Importantly several key immediate early genes were inhibited in mg. 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: mg non-activated mg 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 mg units were place in the static positions for continued mg exposure. After 30 minutes of pre-incubation mg non-activated units were fixed by addition of RNALater (QIAGEN Valencia CA) removed from the incubator and stored in 4 xc2 xb0C. The mg 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 xc2 xb0C storage. All units were returned to Earth for analysis.

Anticipating the risk for infectious disease during space exploration and habitation is a critical factor to ensure safety health and performance of the crewmembers. As a ubiquitous environmental organism that is occasionally part of the human flora Pseudomonas aeruginosa could pose a health hazard for the immuno-compromised astronauts. In order to gain insights in the behavior of P. aeruginosa in spaceflight conditions two spaceflight-analogue culture systems i.e. the rotating wall vessel (RWV) and the random position machine (RPM) were used. Microarray analysis of P. aeruginosa PAO1 grown in the low shear modeled microgravity (LSMMG) environment of the RWV compared to the normal gravity control (NG) revealed a regulatory role for AlgU (RpoE). Specifically P. aeruginosa cultured in LSMMG exhibited increased alginate production and up-regulation of AlgU-controlled transcripts including those encoding stress-related proteins. This study also shows the involvement of Hfq in the LSMMG response consistent with its previously identified role in the Salmonella LSMMG- and spaceflight response. Furthermore cultivation in LSMMG increased heat and oxidative stress resistance and caused a decrease in the culture oxygen transfer rate. Interestingly the global transcriptional response of P. aeruginosa grown in the RPM was similar to that in NG. The possible role of differences in fluid mixing between the RWV and RPM is discussed with the overall collective data favoring the RWV as the optimal model to study the LSMMG-response of suspended cells. This study represents a first step towards the identification of specific virulence mechanisms of P. aeruginosa activated in response to spaceflight-analogue conditions and could direct future research regarding the risk assessment and prevention of Pseudomonas infections for the crew in flight and the general public.

Spaceflight imposes numerous adaptive challenges for terrestrial life. The reduction in gravity or microgravity represents a novel environment that can disrupt homeostasis of many physiological processes. Additionally it is becoming increasingly clear that an organism s microbiome is critical for host health and examining its resiliency in microgravity represents a new frontier for space biology research. In this study we examine the impact of microgravity on the interactions between the squid Euprymna scolopes and its beneficial symbiont Vibrio fischeri which form a highly specific binary mutualism. First animals inoculated with V. fischeri aboard the space shuttle showed effective colonization of the host light organ the site of the symbiosis during spaceflight. Second RNA-Seq analysis of squid exposed to modeled microgravity conditions exhibited extensive differential gene expression in the presence and absence of the symbiotic partner. Transcriptomic analyses revealed in the absence of the symbiont during modeled microgravity there was an enrichment of genes and pathways associated with the innate immune and oxidative stress response. The results suggest that V. fischeri may help modulate the host stress responses under modeled microgravity. This study provides a window into the adaptive responses that the host animal and its symbiont use during modeled microgravity.

The aim of this work is to determine whether mycobacteria have enhanced virulence during space travel and what mechanisms they use to adapt to microgravity. M. marinum and LHM4 were grown in high aspect ratio vessels (HARV) in a rotary cell culture system (RCCS) under normal gravity (NG) or low shear simulated microgravity (MG). To determine the effect of MG on the stress responses activated by the growth conditions we used RNAseq to examine what genes were expressed. For RNAseq the bacteria are harvested RNA isolated and converted DNA (cDNA) and the cDNA sequenced. Using bioinformatics the amount of expression of the different M. marinum genes were compared between the NG and MG samples. To make sure that we were examining only gene expression changes due to MG only bacteria in early exponential growth were used in the RNAseq studies. Triplicate NG and MG cultures were used to generate samples of bacteria grown for ~40 hrs. We also grew triplicate cultures for 4 days and then diluted them again and grew them for another ~40 hrs so we could examine gene expression from bacteria exposed for a longer time. In summary this study determined that waterborne mycobacteria alter their growth expression of stress responses and their sensitivity to oxidizing conditions when subjected to growth under MG.