We investigated differentially regulated and stably expressed genes in human Jurkat T lymphocytic cells in 5min simulated microgravity and hypergravity and compared expression profiles to identify gravity-regulated and unaffected genes as well as adaptation processes.

We investigated differentially regulated genes in human Jurkat T lymphocytic cells in 20s and 5min microgravity and in hypergravity and compared expression profiles to identify potential gravity-regulated genes and adaptation processes.

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.

Controlled hypobaria presents biology with an environment that is never encountered in terrestrial ecology yet the apparent components of hypobaria are stresses typical of terrestrial ecosystems. High altitude for example presents terrestrial hypobaria always with hypoxia as a component stress since the relative partial pressure of O2 is constant in the atmosphere. Laboratory-controlled hypobaria however allows the dissection of pressure effects away from the effects typically associated with altitude in particular hypoxia as the partial pressure of O2 can be varied. In this study whole transcriptomes of plants grown in ambient (97 kPa/pO2 = 21 kPa) atmospheric conditions were compared to those of plants transferred to five different atmospheres of varying pressure and oxygen composition for 24 h: 50 kPa/pO2 = 10 kPa 25 kPa/pO2 = 5 kPa 50 kPa/pO2 = 21 kPa 25 kPa/pO2 = 21 kPa or 97 kPa/pO2 = 5 kPa. The plants exposed to these environments were 10 day old Arabidopsis seedlings grown vertically on hydrated nutrient plates. In addition 5 day old plants were also exposed for 24 h to the 50 kPa and ambient environments to evaluate age-dependent responses. The gene expression profiles from roots and shoots showed that the hypobaric response contained more complex gene regulation than simple hypoxia and that adding back oxygen to normoxic conditions did not completely alleviate gene expression changes in hypobaric responses.

We investigated differentially regulated genes in human Jurkat T lymphocytic cells in 20s and 5min microgravity and in hypergravity and compared expression profiles to identify potential gravity-regulated genes and adaptation processes.

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.

Accumulating data suggest that the biological responses to high and low doses of radiation are qualitatively different necessitating the direct study of low dose responses. Most such studies have utilized 2-dimensional culture systems which may not fully represent responses in 3-dimensional tissues. To gain insight into low dose responses in tissue we have profiled global gene expression in EPI-200 a 3-dimensional tissue model from MatTek that imitates the structure and function of human epidermis at 4 16 and 24 hours after exposure to high (2.5 Gy) and low (0.1 Gy) doses of low LET protons. Untreated controls and samples exposed to 10 cGy or to 2.5 Gy were analyzed at three different times (4 16 or 24 hours after exposure). Three biological repeats were performed for each condition

DLD-1 and MOLT-4 cell lines were cultured in a Rotating cell culture system to simulate microgravity and mRNA expression profile was observed in comparison to Static controls. Cells were grown in 10mL rotating vessels in an RCCS and in 60mm Petri dishes (test control respectively).Two replicates of test (Microgravity) and control (static) each from DLD-1 and MOLT-4 were analyzed by microarray. Simulated microgravity affected the solid tumor cell line DLD-1 markedly which showed a higher percentage of dysregulated genes compared to the hematological tumor cell line MOLT-4. Microgravity affects the cell cycle of DLD-1 cells and disturbs expression of cell cycle regulatory gene networks. Multiple microRNA host genes were dysregulated and significantly mir-22 tumor suppressor microRNA is highly upregulated in DLD-1.

Comparitive gene expression in skin between mice maintained in microgravity (0g) and normogravity (1g) environment. Six male C57Bl/J10 mice were housed for 91 days in the specially designed Mouse Drawer System in weightlessness aboard the International Space Station. Three wild-type mice (WT) and three transgenic mice overexpressing the osteogneic factor PTN/OSF1 under the control of the human bone specific ostecalcin promoter (Tg) were used in the experiment. During the 3-month stay on the ISS 3 mice unfortunately died leaving 2 Tg and 1 WT. MDS tissue sharing program allowed several teams to study various tissues from these mice. Our aim was to investigate the effect of such a long period of microgravity on skin physiology by morphological biochemical and genomewide analyses by comparison to similar mice on ground. Gene expression in the skin of 3 space mice and of 3 ground mice was analyzed by microarray. As this unique experiment performed on 3 mice limits the power of statistical analyis as the transgene PTN/OSF1 was not overexpressed in skin and as a pair wise Pearson s correlation rates between the individual levels of expressed transcripts in the WT and the Tg mice were not significantly different from each other in one experimental group (space or ground) data from the 3 mice were combined to compare results from the space an ground groups.

Genome-wide transcriptional profiling showed that reducing gravity levels in the International Space Station (ISS) causes important alterations in Drosophila gene expression intimately linked to imposed spaceflight-related environmental constrains during Drosophila metamorphosis. However simulation experiments on ground testing space-related environmental constraints show differential responses. Curiously although particular genes are not common in the different experiments the same GO groups including a large multigene family related with behavior stress response and organogenesis are over represented in them. A global and integrative analysis using the gene expression dynamics inspector (GEDI) self-organizing maps reveals different degrees in the responses of the transcriptome when using different environmental conditions or microgravity/hypergravity simulation devices. These results suggest that the transcriptome is finely tuned to normal gravity. In regular environmental conditions the alteration of this constant parameter on Earth can have mild effects on gene expression but when environmental conditions are far from optimal the gene expression is much more intense and consistent effects.