['Microgravity is one of the most important features in spaceflight. Previous evidence has shown that significant changes to the musculoskeletal and immune systems occurred under microgravity. The present study was undertaken to explore the change in protein abundance in human colon colorectal cells that were incubated for 48 or 72 h either in normal conditions and µG simulated conditions. The comparative proteomic method based on the 18O labeling technique was applied to investigate the up-regulated proteins and down-regulated proteins in SH-SY5Y under simulated microgravity.']

The proteomics experiment involved analyzing the protein expression profiles of Enterobacter cloacae under different gravity conditions simulated in High Aspect Ratio Vessels (HARVs). The three conditions studied were normal gravity (NG), inverted normal gravity (INV), and low shear modeled microgravity (LSMMG). The goal was to assess how E. cloacae adapts to microgravity, given its relevance to astronaut health during spaceflight. By comparing the proteomic profiles across these conditions, the study identified significant changes in protein expression in LSMMG and INV compared to NG.

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.

Background/Objectives: The waterflea Daphnia is an interesting candidate for bioregenerative life support systems (BLSS). These animals are particularly promising because of their central role in the limnic food web and its mode of reproduction. However the response of Daphnia to altered gravity conditions has to be investigated especially on the molecular level to evaluate the suitability of Daphnia for BLSS in space. Methods: In this study we applied a proteomic approach to identify key proteins and pathways involved in the response of Daphnia to simulated microgravity generated by a 2D-clinostat. We analysed 5 biological replicates using 2D-DIGE proteomic analysis. Results: We identified 109 protein spots differing in intensity (p < 0.05). Substantial fractions of these proteins are involved in actin microfilament organisation indicating the disruption of cytoskeletal structures during clinorotation. Furthermore proteins involved in protein folding were identified suggesting altered gravity induced breakdown of protein structures in general. In addition simulated microgravity increased the abundance of energy metabolism related proteins indicating an enhanced energy demand of Daphnia. Conclusion: The affected biological processes were also described in other studies using different organisms and systems either aiming to simulate microgravity conditions or providing real microgravity conditions. Moreover most of the Daphnia protein sequences are well conserved throughout taxa indicating that the response to altered gravity conditions in Daphnia follows a general concept.

Background/Objectives: The waterflea Daphnia is an interesting candidate for bioregenerative life support systems (BLSS). These animals are particularly promising because of their central role in the limnic food web and its mode of reproduction. However the response of Daphnia to altered gravity conditions has to be investigated especially on the molecular level to evaluate the suitability of Daphnia for BLSS in space. Methods: In this study we applied a proteomic approach to identify key proteins and pathways involved in the response of Daphnia to simulated microgravity generated by a 2D-clinostat. We analysed 5 biological replicates using 2D-DIGE proteomic analysis. Results: We identified 109 protein spots differing in intensity (p < 0.05). Substantial fractions of these proteins are involved in actin microfilament organisation indicating the disruption of cytoskeletal structures during clinorotation. Furthermore proteins involved in protein folding were identified suggesting altered gravity induced breakdown of protein structures in general. In addition simulated microgravity increased the abundance of energy metabolism related proteins indicating an enhanced energy demand of Daphnia. Conclusion: The affected biological processes were also described in other studies using different organisms and systems either aiming to simulate microgravity conditions or providing real microgravity conditions. Moreover most of the Daphnia protein sequences are well conserved throughout taxa indicating that the response to altered gravity conditions in Daphnia follows a general concept.

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.

Here in this study we systematically examined the patterns of DNA methylation and hydroxy-methylation with its functional implications in gene regulation for the cultured TK6 lymphoblastoid cells upon exposure to micro-gravity conditions. The results reported here indicate that simulated microgravity alters methylation patterns in a limited way and subsequently the expression of genes involved in stress response like ATF3 FBXO17 MAP3K13 and VCL in TK6 cells. Overall design: Examination of RNA-seq with 2 replicates each for 1 cell type

The introduction of generally recognized as safe (GRAS) probiotic microbes into the spaceflight food system has the potential for use as a safe, non-invasive, daily countermeasure to crew microbiome and immune dysregulation. However, the microgravity effects on the stress tolerances and genetic expression of probiotic bacteria must be determined to confirm translation of strain benefits and to identify potential for optimization of growth, survival, and strain selection for spaceflight. The work presented here demonstrates the translation of characteristics of a GRAS probiotic bacteria to a microgravity analog environment. Lactobacillus acidophilus ATCC 4356 was grown in the low shear modeled microgravity (LSMMG) orientation and the control orientation in the rotating wall vessel (RWV) to determine the effect of LSMMG on the growth, survival through stress challenge, and gene expression of the strain. No differences were observed between the LSMMG and control grown L. acidophilus, suggesting that the strain will behave similarly in spaceflight and may be expected to confer Earth-based benefits.

The microgravity environment aboard the International Space Station (ISS) provides a unique stressor that can help understand underlying cellular and molecular drivers of pathological changes observed in astronauts with the ultimate goals of developing strategies to enable long- term spaceflight and better treatment of diseases on Earth. We used this unique environment to evaluate the effects of microgravity on kidney proximal tubule epithelial cell (PTEC) response to serum exposure and vitaminD biotransformation capacity. To test if microgravity alters the pathologic response of the proximal tubule to serum exposure, we treated PTECs cultured in a microphysiological system (PT-MPS) with human serum and measured biomarkers of toxicity and inflammation (KIM-1 and IL-6) and conducted global transcriptomics via RNAseq on cells undergoing flight (microgravity) and respective controls(ground). Given the profound bone loss observed in microgravity and PTECs produce the active form of vitamin D, we treated 3D cultured PTECs with 25(OH)D 3 (vitamin D) and monitored vitamin D metabolite formation, conducted global transcriptomics via RNAseq, and evaluated transcript expression of CYP27B1, CYP24A1, or CYP3A5 in PTECs undergoing flight (microgravity) and respective ground controls. We demonstrated that microgravity neither altered PTEC metabolism of vitamin D nor did it induce a unique response of PTECs to human serum, suggesting that these fundamental biochemical pathways in the kidney proximal tubule are not significantly altered by short-term exposure to microgravity. Given the prospect of extended spaceflight, more study is needed to determine if these responses are consistent with extended (greater than 6 months) exposure to microgravity.