Background: mRNA interactions with each other and other signaling molecules define different biological pathways and functions. Researchers have been investigating various tools to analyze these types of interactions. In particular gene co-expression network methods have proved useful in finding and analyzing these molecular interactions. Many different analytical pipelines to identify these interactions networks have been proposed with the aim of identifying an optimal partition of the network where the individual modules are neither too small to make any general inference or too large to be biologically interpretable. Results: In this study we propose a new pipeline to perform gene co-expression network analysis. The proposed pipeline uses WGCNA a widely used software to perform different aspects of gene co-expression network analysis and modularity maximization algorithm to analyze novel RNA-Seq data to understand the effects of low-dose 56Fe ion irradiation on the formation of hepatocellular carcinoma in mice. The network results along with experimental validation show that using WGCNA combined with Modularity provide a more biologically interpretable network in our dataset. Our pipeline showed better performance than the existing clustering algorithm in WGCNA in finding modules and identified a module with mitochondrial subunits that are supported by mitochondrial complex assay. Conclusions: We present a pipeline that can reduce the problem of parameter selection with the existing algorithm in WGCNA for comparable RNA-Seq datasets which may assist in future research to discover novel mRNA interactions and their downstream molecular effects. C57BL16 males were placed into 2 treatment groups and received the following irradiation treatments at Brookhaven National Laboratories (Long Island NY): 600 MeV/n 56Fe (0.2 Gy) and no irradiation. Left liver lobes were collected at 30 60 120 270 and 360 days post-irradiation flash frozen and stored at -80 xc2 xb0C until they could be processed for RNA-Seq. Livers were sampled by taking two 40-micron thick slices using a cryotome at -20 xc2 xb0C. This allowed multiple sampling of the tissue without the tissue going through multiple freeze/thaw cycles. Total RNA was isolated from the liver slices using RNAqueousTM Total RNA Isolation Kit (ThermoFisher Scientific Waltham MA) and rRNA was removed via Ribo-ZeroTM rRNA Removal Kit (Illumina San Diego CA) prior to library preparation with the Illumina TruSeq RNA Library kit. Samples were sequenced in a paired-end 50 base format on an Illumina HiSeq 1500. Reads were aligned to the mouse GRCm38 reference genome using the STAR alignment program version 2.5.3a with the recommended ENCODE options. The -quantMode GeneCounts option was used to obtain read counts per gene based on the Gencode release M14 annotation file. Total number of reads used in analysis varies between 23-35 millions of reads.

The Cosmic Ray Exposure Sequencing Science (CRESS) payload system is a proof of concept experiment to assess the genomic impact of space radiation on seeds. CRESS was designed as a secondary payload for the December 2016 high-altitude high-latitude and long-duration balloon flight carrying the Boron And Carbon Cosmic Rays in the Upper Stratosphere (BACCUS) experimental hardware. Investigation of the biological effects of Galactic Cosmic Radiation (GCR) particularly those of ions with High-Z and Energy (HZE) is of interest due to the genomic damage this type of radiation inflicts. The biological effects of upper-stratospheric mixed radiation above Antarctica (ANT) were sampled using Arabidopsis thaliana seeds and were compared to those resulting from a controlled simulation of GCR at Brookhaven National Laboratory (BNL) and to laboratory control seed. The payload developed for Antarctica exposure was broadly designed to 1U CubeSat specifications (10cmx10cmx10cm <1.33kg) maintained 1 atm internal pressure and carried an internal cargo of four seed trays (about 580,000 seeds) and twelve CR-39 Solid-State Nuclear Track Detectors (SSNTDs). The irradiated seeds were recovered sterilized and grown on Petri plates for phenotypic screening. BNL and ANT M0 seeds showed significantly reduced germination rates and elevated somatic mutation rates when compared to non-irradiated controls with the BNL mutation rate also being significantly higher than that of ANT. Genomic DNA from mutants of interest was evaluated with whole-genome sequencing using PacBio SMRT technology. Sequence data revealed the presence of an array of genome structural variants in the genomes of M0 and M1 mutant plants.

Biological risks associated with space radiation and microgravity are major concerns for long-term space travel. Through a Systems Biology approach our previous NASA work has shown both TGF xce xb2 signaling pathways and miRNAs have a critical impact on defining health risks with and without space irradiation. We hypothesize that circulating microRNA (miRNA) signatures are driving microvascular disease and muscle degeneration associated with accelerating aging and will be enhanced by exposure to the space environment (radiation and microgravity). We investigated this hypothesis both in vivo and in vitro and test novel antagonist therapies to these miRNA signatures as countermeasures to reduce space radiation-induced health risks. A comprehensive Systems Biology approach was used to examine the influence by high atomic number by high (H) atomic number (Z) and energy (E) (HZE) irradiation. To simulate low-dose exposure due to galactic cosmic rays (GCR) we used the ions energy and doses determined by a NASA consensus formula of 7 different ions to represent GCR (referred to as GCR sim model). To simulate high-dose radiation exposure due to solar particle events (SPE) we used an acute dose of SPE simulated beam at 1Gy which has energies ranging from 50MeV to 150MeV. C57BL/6 wild-type mice were utilized for irradiation with our established simulated microgravity model (hindlimb suspension model) and an in vitro 3D microvasculature tissue model under simulated microgravity (clinostat) conditions will also be irradiated. To expand on the circulating miRNA signature determined from our preliminary data we determined a group of conserved miRNAs which are commonly being regulated in the majority of the organs and tissues throughout the host using our established techniques. MiRNA-sequencing on serum (before IR and at time of sacrifice) liver heart and muscle tissue for all radiation groups revealed the key circulating miRNA signature (consisting of multiple miRNAs) impacting disease risk. Collectively understanding of how whole body space radiation impacts microvascular and tissue degeneration through circulating miRNAs will greatly enhance health risk prognostication and provide possible new mechanisms for protection against space radiation.

The purpose of this study was to evaluate transcriptional changes in mouse spleens using a ground-based model for spaceflight. This model includes prolonged unloading and low-dose irradiation. Low-dose-rate gamma-radiation was delivered to 6-month old female C57BL/6J mice using 57Co plates (0.04 Gy) to simulate the radiation environment of spaceflight. Anti-orthostatic tail suspension was used to model the unloading fluid shift and physiological stress aspects of the microgravity component of spaceflight. Mice were hindlimb suspended and/or irradiated for 21 days. Mice were euthanized and spleens collected 7 days following treatment. RNA sequencing data was generated to assess transcriptional changes in these spleens.

Physical inactivity decreases the mechanical load on the skeleton which when prolonged leads to losses of muscle strength and bone mass in humans and most mammalian species. Hibernating mammals show no loss in bone mass and less muscle atrophy than would be anticipated over such a prolonged period of physical inactivity. This suggests that diverse hibernating mammals have evolved natural mechanisms that reduce muscle atrophy and conserve bone mass.

Adaptation of humans in low gravity conditions is a matter of utmost importance when efforts are on to a gigantic leap in human space expeditions for tourism and formation of space colonies. In this connection cardiovascular adaptation in low gravity is a critical component of human space exploration. Deep high-throughput sequencing approach allowed us to analyze the miRNA and mRNA expression profiles in human umbilical cord vein endothelial cells (HUVEC) cultured under gravity (G) and stimulated microgravity (MG) achieved with a clinostat. The present study identified totally 1870 miRNAs differentially expressed in HUVEC under MG condition when compared to the cells subjected to unitary G conditions. The functional association of identified miRNAs targeting specific mRNAs revealed that miRNAs hsa-mir-496 hsa-mir-151a hsa-miR-296-3p hsa-mir-148a hsa-miR-365b-5p hsa-miR-3687 hsa-mir-454 hsa-miR-155-5p and hsa-miR-145-5p differentially regulated the genes involved in cell adhesion angiogenesis cell cycle JAK-STAT signaling MAPK signaling nitric oxide signaling VEGF signaling and wound healing pathways. Further the q-PCR based experimental studies of upregulated and downregulated miRNA and mRNAs demonstrate that the above reported miRNAs influence the cell proliferation and vascular functions of the HUVEC in MG conditions effectively. Consensus on the interactome results indicates restricted fluctuations in the transcriptome of the HUVEC exposed to short-term MG that could lead to higher levels of endothelial functions like angiogenesis and vascular patterning.

The objective of the Rodent Research-6 (RR-6) study was to evaluate muscle atrophy in mice during spaceflight and to test the efficacy of a novel therapeutic to mitigate muscle wasting. The experiment involved an implantable subcutaneous nanochannel delivery system (nDS; between scapula) which delivered the drug formoterol (FMT; a selective xce xb22 adrenoceptor agonist) over the course of time. To this end a cohort of forty 32-weeks-old female C57BL/6NTac mice were either sham operated or implanted with vehicle or treatment-filled nDS launched in two Transporters (20 mice per Transporter) on SpaceX-13 on December 15 2017. They were transferred to Rodent Habitats onboard the International Space Station (ISS) and maintained in microgravity for 29 days (N=20 Live Animal Return Spaceflight [LAR FLT]) or >50 days (N=20 ISS Terminal Spaceflight [ISS-T FLT]). After 29 days the 20 LAR FLT animals were returned live to back to Earth on January 13 2018. After splashdown the animals were ambulatory on-ground for ~4 days until all subjects were processed during one day of dissections. There were two Basal (BSL) groups of animals sacrificed (LAR BSL & ISS-T BSL; N=20; 40 animals; ~36 weeks old) at Kennedy Space Center (KSC; 12/9/17). LAR BSL animals were dissected and samples were collected upon euthanasia. A Ground Control (GC) group LAR GC mimicked the LAR FLT group which was housed at KSC then shipped alive to Novartis xe2 x80 x99s Facilities where both the LAR FLT and LAR GC groups were processed (~41 weeks old; 1/16/18). All were anesthetized with isoflurane blood samples were obtained by closed-chest cardiac puncture and the animals were euthanized by exsanguination and thoracotomy. The 20 ISS-T FLT mice were anesthetized via intraperitoneal injection of ketamine/xylazine/acepromazine over the course of a four days of dissections (2/6/18 until 2/9/18; 53-56 days after launch; 44 weeks old at time of on-orbit dissections). Blood samples and euthanasia were conducted the same as LAR groups. Following blood draw and hind limb dissection the ISS-T FLT animal carcasses were wrapped in aluminum foil placed in a ziploc bag and placed in storage at -80 xcb x9aC or colder until return. The ISS-T Ground Control (ISS-T GC) (at KSC) followed the same euthanasia timeline methods and preservation. The final processing of frozen ISS-T FLT frozen ISS-T GC and frozen 0-day ISS-T BSL animals were completed at Houston Methodist Research Institute in Houston TX (5/21/18 until 5/24/18). GeneLab received feces from only sham treated animals (no drug treated animals) from the following groups. FLT: LAR (n=9) ISS-T (n=7); GC: LAR (N=7) ISS-T (N=9); BSL: LAR (n=7) ISS-T (n=9). DNA was extracted and analyzed by sequencing using a variety of different targeted and un-targeted metagenome profiling assays.

Immune dysregulation is among the main adverse outcomes of spaceflight. Despite its crucial role in host protection effects on the human antibody repertoire are unknown. Consequently we examined the IgM repertoire of five cosmonauts 25 days before launch after 64 and 129 days spent on the International Space Station (ISS) and after 1 7 and 30 days of Earth reambulation using high-throughput sequencing. This is the first study of this kind. Our data revealed that the IgM repertoire of cosmonauts was different from the one of control subjects already prior to launch and that 2 out the 5 analyzed cosmonauts presented significant changes of their IgM repertoire during the mission. These modifications persisted up to 30 days after landing likely affected the specificities of IgM binding sites correlated with changes of the V(D)J recombination process in charge of creating functional antibody genes and coincided with a higher stress response. These data confirm that about half of the astronauts who spent six months on the ISS are subjected to immunological changes contribute to explain increased susceptibility to infection reveal individual responses and consequently that personalized approaches should be implemented during future deep-space exploration missions that will endure for an unprecedented amount of time.

The purpose of this study was to evaluate transcriptional changes in mouse skin using a ground-based model for spaceflight. This model includes prolonged unloading and low-dose irradiation. Low-dose-rate gamma-radiation was delivered to 6-month old female C57BL/6J mice using 57Co plates (0.04 Gy) to simulate the radiation environment of spaceflight. Anti-orthostatic tail suspension was used to model the unloading fluid shift and physiological stress aspects of the microgravity component of spaceflight. Mice were hindlimb suspended and/or irradiated for 21 days. Mice were euthanized and dorsal skin was collected 7 days following treatment. RNA sequencing data was generated to assess transcriptional changes in these skin samples.

Biological risks associated with space radiation and microgravity are major concerns for long-term space travel. Through a Systems Biology approach our previous NASA work has shown both TGF xce xb2 signaling pathways and miRNAs have a critical impact on defining health risks with and without space irradiation. We hypothesize that circulating microRNA (miRNA) signatures are driving microvascular disease and muscle degeneration associated with accelerating aging and will be enhanced by exposure to the space environment (radiation and microgravity). We investigated this hypothesis both in vivo and in vitro and test novel antagonist therapies to these miRNA signatures as countermeasures to reduce space radiation-induced health risks. A comprehensive Systems Biology approach was used to examine the influence by high atomic number by high (H) atomic number (Z) and energy (E) (HZE) irradiation. To simulate low-dose exposure due to galactic cosmic rays (GCR) we used the ions energy and doses determined by a NASA consensus formula of 7 different ions to represent GCR (referred to as GCR sim model). To simulate high-dose radiation exposure due to solar particle events (SPE) we used an acute dose of SPE simulated beam at 1Gy which has energies ranging from 50MeV to 150MeV. C57BL/6 wild-type mice were utilized for irradiation with our established simulated microgravity model (hindlimb suspension model) and an in vitro 3D microvasculature tissue model under simulated microgravity (clinostat) conditions will also be irradiated. To expand on the circulating miRNA signature determined from our preliminary data we determined a group of conserved miRNAs which are commonly being regulated in the majority of the organs and tissues throughout the host using our established techniques. MiRNA-sequencing on serum (before IR and at time of sacrifice) liver heart and muscle tissue for all radiation groups revealed the key circulating miRNA signature (consisting of multiple miRNAs) impacting disease risk. Collectively understanding of how whole body space radiation impacts microvascular and tissue degeneration through circulating miRNAs will greatly enhance health risk prognostication and provide possible new mechanisms for protection against space radiation.