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.

Understanding plant adaptive responses to the space environment is a requisite for enabling space farming. Spaceflight produce deleterious effects on plant cells particularly affecting ribosome biogenesis a complex stress-sensitive process coordinated with cell division and differentiation known to be activated by red light. Here we have used mutants from the two nucleolin genes in Arabidopsis (NUC1 and NUC2) encoding the main regulator of the ribosome biogenesis in the nucleolus in order to better understand their role in adaptive response mechanisms to stress. Thus we show that nucleolin stress-related gene NUC2 can compensate the environmental stress provided by darkness in nuc1 plants while nuc2 plants are not able to provide a complete response to red light. These ground control findings as part of the ESA/NASA Seedling Growth spaceflight experiments will determine the basis for the identification of a genetic background enabling an adaptive advantage for plants in future space experiments.

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.

In the Rocket Science citizen science project Eruca sativa (salad rocket) seeds stored for six months on board of the International Space Station caused delayed crop establishment. Here we investigated the physiological and molecular mechanisms underpinning the spaceflight effects on dry seeds. We found that Space seed germination vigor was reduced and aging sensitivity increased but the spaceflight did not compromise seed viability and the development of normal seedlings. Comparative analysis of the transcriptomes (using RNASeq) in dry seeds and upon controlled artificial aging treatment (CAAT) revealed differentially expressed genes (DEGs) associated with spaceflight and ageing. DEG categories enriched by spaceflight and CAAT included transcription and translation with reduced transcript abundances for 40S and 60S ribosomal subunit genes. Among the spaceflight-up DEGs were Heat Shock Protein (HSP) DNAJ-related chaperones a Heat Shock Factor (HSFA7a-like) and components of several DNA repair pathways (e.g. ATM DNA ligase1). The response to radiation category was especially enriched in spaceflight-up DEGs including HSPs catalases and the transcription factor HY5. The major finding from the physiological and transcriptome analysis is that spaceflight causes vigor loss and partial ageing during air-dry seed storage for which space environmental factors and consequences for seed storage during spaceflights are discussed.

Four days old rice calli were selected to grow 324h under spaceflight controls 1g-flight controls and 1g-ground controls. We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. Rice calli were selected at different treatment for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain the diff-genes that caused by the microgravity.

The development of Col-0 and WS plants on orbit differs from that on the ground as demonstrated by the comparison of the gene expression profiles between 4 days old to 8 days old plant in the two environments. The Col-0 plants used different genes reflecting different physiological processes than WS plants suggesting the role of the genetic background in the developmental decisions. The 4 days old Col-0 plant in orbit showed deficit in wax and suberin production relatively to the 8 days old plants the difference unregistered on the ground. There was more dramatic difference in the overexpression of the root system development and anatomical structure development genes in 8 days old plants than in 4 days old plant in both genotypes on the ground than in flight implying smaller root developmental gap between 4 days and 8 days old roots in orbit. The WS plant uniquely showed overexpression of the photosynthesis related genes in the 4 days old roots relative to 8 days old root in the spaceflight environment but not on the ground. The seeds germinated in the novel growth environment of ISS implemented different developmental strategies as captured by the genes expression patterns than seeds developing on the ground.

Plants exhibit a robust transcriptional response to gamma radiation which includes the induction of transcripts required for homologous recombination and the suppression of transcripts that promote cell cycle progression. Various DNA damaging agents induce different spectra of DNA damage as well as collateral damage to other cellular components and therefore are not expected to provoke identical responses by the cell. Here we study the effects of two different types of ionizing radiation (IR) treatment HZE (1 GeV Fe26+ high mass high charge and high energy relativistic particles) and gamma photons on the transcriptome of Arabidopsis thaliana seedlings. Both types of IR induce small clusters of radicals that can result in the formation of double strand breaks (DSBs) but HZE also produces linear arrays of extremely clustered damage. We performed these experiments across a range of time points (1.5-24 h after irradiation) in both wild-type plants and in mutants defective in the DSB-sensing protein kinase ATM. The two types of IR exhibit a shared double strand break-repair-related damage response although they differ slightly in the timing degree and ATM-dependence of the response. The ATM-dependent DNA metabolism-related transcripts of the DSB response were also induced by other DNA damaging agents but were not induced by conventional stresses. Both Gamma and HZE irradiation induced at 24 h post-irradiation ATM-dependent transcripts associated with a variety of conventional stresses; these were overrepresented for pathogen response rather than DNA metabolism. In contrast only HZE-irradiated plants at 1.5 h after irradiation exhibited an additional and very extensive transcriptional response shared with plants experiencing extended night. This response was not apparent in gamma-irradiated plants.

Analysis of effect of hindlimb suspension and reloading on C57Bl/6 mouse soleus muscle. Experimental groups examined: -Control mice 14 days -Hindlimb suspension for 7 days -Hindlimb suspension for 7 days and subsequent reloading for 1 day -Hindlimb suspension for 7 days and subsequent reloading for 7 days

Previous spaceflight experiments using Bacillus subtilis have reported altered transcriptome profiles during spaceflight compared to matching ground samples. This study tried to replicate those transcriptome changes using High Aspect Ratio Vessels (HARVs). B. subtilis spores were grown in HARVs using the same protocol and growth conditions as the BRIC-23 spaceflight mission. RNA was extracted from the HARV samples and sequenced for differential expression analysis. HARV differentially expressed genes were then compared to the genes identified as differentially expressed in the BRIC-23 mission to access the accuracy of HARVs as a model for spaceflight experiments.

With extended stays aboard the International Space Station (ISS) becoming commonplace there is a need to better understand the effects of microgravity on cardiac function. We utilized human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to study the effects of microgravity on cell-level cardiac function and gene expression. The hiPSC-CMs were cultured aboard the ISS for 5.5 weeks and their gene expression structure and functions were compared to ground control hiPSC-CMs. Exposure to microgravity on the ISS caused alterations in hiPSC-CM calcium handling. RNA-sequencing analysis demonstrated 2,635 genes were differentially expressed among flight post-flight and ground control samples including genes involved in mitochondrial metabolism. This study represents the first use of hiPSCs to model the effects of spaceflight on human cardiomyocyte structure and function.