Project description:Euglena gracilis is a unicellular freshwater flagellate, which uses the gravitational vector for orientation in the water column in the dark. This allows the cell to reach areas in the water column for reproduction and growth. How exactly the gravitational vector is perceived, and which intracellular pathways are involved in the signaling is not very well understood so far. In the past, parabolic flight campaigns were used to study the swimming behavior of Euglena gracilis under altered gravitational accelerations. It was shown that cells adapt their swimming direction very fast: in the dark under 1xg cell show negative gravitaxis, i.e. they move upwards in the water column of the experiment hardware and against the gravitational vector. With onset of the first hypergravity period of 1.8xg the precision of upward swimming increases slightly. This first hyper gravity lasts for only 20 seconds and is followed by 22 sec of microgravity. During this period no gravitational vector is perceived by the cells, therefore they lack a cue for orientation and move randomly in all direction. In the subsequent hyper gravity period of 1.8xg, which also lasts for 20 sec, cells direct their movement again and swim upwards. Over different parabolic flight campaigns and other experiments it was shown that this gravitactic behavior is linked to changes in membrane potential, calcium and cAMP concentration. However, due to the lack of genomic and transcriptomic data, it was so far not possible to link the differential movement to the abundance of distinct mRNA transcripts. In contrast, other model organisms, such as Arabidopsis thaliana, have been analyzed by means of gene expression with respect to the effects of altered gravitational accelerations. Also various human cell lines have shown to adapt their gene expression in dependence of the prevailing acceleration. With the recently published Euglena gracilis transcriptome, we now aimed at analyzing effects of altered acceleration on the gene expression in the flagellate. Therefore, Euglena gracilis samples were taken in the course of the 29th DLR parabolic flight campaign during parabola 1 and 31 (time difference of 2 hours and 30 additional parabolas). During both parabolas samples were fixed with TRIzol at 1xg just before onset of the first hyper gravity period, 20 sec into hyper gravity (1.8xg), 20 sec into microgravity (µg) and 20 sec into the last hypergravity period.
Project description:BACKGROUND: Understanding physiologic reactions to weightlessness is an indispensable requirement for safe human space missions. While adaptations of human organ systems in response to weightlessness have been described in former studies, their molecular background needs further elucidation. OBJECTIVE: The study aims to analyse changes in the expression of circulating miRNAs in serum in response to gravitational changes induced by parabolic flight as a spaceflight analogue. METHODS: Eight healthy volunteers (age: 25.4 years, male: 4, female: 4) were included. Each subject underwent 31 short-term phases of weightlessness and hypergravity induced by parabolic flight. At different time points (baseline, 1 hour after parabolic flight, and 24 hours parabolic flight), venous blood was withdrawn. Analysis of circulating miRNAs in serum was conducted by means of next generation sequencing. RESULTS: In total, 213 miRNAs were robustly detected by small RNA sequencing in all 24 samples. 4 miRNAs (mir-941, mir-24-3p, mir-486-5p, mir-223-3p) evidenced a significant change in expression after adjusting for multiple testing. mir-941 and mir-24-3p showed a significant decrease 24 hours after parabolic flight compared to 1 hour after parabolic flight. Contrary, mir-486-5p showed a significant increase 24 hours after parabolic flight compared to 1 hour after parabolic flight. Of note, mir-223-3p showed a significant decrease 24 hours after parabolic flight compared to baseline values and values at 1 hour after parabolic flight. A target network analysis identified genes of the p53 signaling pathway and the cell cycle highly enriched among the targets of the four microRNAs. CONCLUSIONS: Our findings suggest cellular adaption to gravitational changes by means of weightlessness and hypergravity already at the transcriptional level. Based on our results, we suggest a change in cell cycle regulation as potential explanation for adaptational changes observed in space missions.
Project description:Jurkat T cells have been fixated at different gravity conditions during the 4th Swiss Parabolic Flight Campaign (4SPFC). 1g inflight samples were generated by crosslinking 5 minutes prior to onset of the first parabola. Hypg samples were generated by crosslinking the samples at the end of the first hypergravity 1.8 g phase, 20 seconds after start of the parabola. µg/0g samples were generated by crosslinking the cells 20 seconds after the onset of microgravity during the first parabola. A ground control reference condition was generated by crosslinking cells that were stored inside the flight hardware but were not onboard during the flight.
Project description:The increasing availability of flights on suborbital rockets creates new avenues for the study of spaceflight effects on biological systems, in particular the transitions between hypergravity and microgravity. This paper presents an initial comparison of the responses of Arabidopsis thaliana to suborbital and atmospheric parabolic flights as an important step toward characterizing these emerging suborbital platforms and their effects on biology. Transcriptomic profiling of the response of the Arabidopsis ecotype Wassilewskija (WS) to the aggregate spaceflight experiences in the Blue Origin New Shepard and Virgin Galactic SpaceShipTwo rockets revealed that the transcriptomic load induced by flight differed greatly between the two flights, yet was biologically related to traditional parabolic flight responses. The sku5 skewing mutant and 14-3-3κ:GFP regulatory protein overexpression lines each showed altered intra-platform responses compared to WS in the Blue Origin and parabolic flights, respectively. An additional parabolic flight using the F-104 Starfighter showed that the response of 14-3-3κ:GFP to flight was modulated in a similar manner to the WS line. Despite the differing genotypes, experimental workflows, flight profiles and platforms, alteration of gene expression remodeling central metabolic processes was commonly observed as a response to the flights. The processes included carbon and nitrogen metabolism, branched-chain amino acid degradation, and hypoxic responses. The timing and directionality of differentially-expressed genes involved in the conserved pathways differed among the platforms. The data presented herein highlight the potential for various suborbital platforms to contribute insights into biological responses to spaceflight, and further suggest that in-flight fixation during suborbital experiments will provide insights into responses to each phase of flight.
Project description:The increasing availability of flights on suborbital rockets creates new avenues for the study of spaceflight effects on biological systems, in particular the transitions between hypergravity and microgravity. This paper presents an initial comparison of the responses of Arabidopsis thaliana to suborbital and atmospheric parabolic flights as an important step toward characterizing these emerging suborbital platforms and their effects on biology. Transcriptomic profiling of the response of the Arabidopsis ecotype Wassilewskija (WS) to the aggregate spaceflight experiences in the Blue Origin New Shepard and Virgin Galactic SpaceShipTwo rockets revealed that the transcriptomic load induced by flight differed greatly between the two flights, yet was biologically related to traditional parabolic flight responses. The sku5 skewing mutant and 14-3-3κ:GFP regulatory protein overexpression lines each showed altered intra-platform responses compared to WS in the Blue Origin and parabolic flights, respectively. An additional parabolic flight using the F-104 Starfighter showed that the response of 14-3-3κ:GFP to flight was modulated in a similar manner to the WS line. Despite the differing genotypes, experimental workflows, flight profiles and platforms, alteration of gene expression remodeling central metabolic processes was commonly observed as a response to the flights. The processes included carbon and nitrogen metabolism, branched-chain amino acid degradation, and hypoxic responses. The timing and directionality of differentially-expressed genes involved in the conserved pathways differed among the platforms. The data presented herein highlight the potential for various suborbital platforms to contribute insights into biological responses to spaceflight, and further suggest that in-flight fixation during suborbital experiments will provide insights into responses to each phase of flight.