Epidemiological studies, e.g., on atomic bomb survivors, have shown that exposure to ionizing radiation increases the risk of developing breast cancer. Typically, these studies correlate intrinsic and extrinsic contributing factors with the observed cases of breast cancer in a defined population. In this study, we attempt to model these relationships at the cellular level. For this, a nine-stage model of the epithelial cells in the milk ducts is developed, considering transition probabilities between the stages. As a proof of principle, the transition probabilities between the stages of our model are fit for scenarios with and without exposure to ionizing radiation. Although this model simplifies the complex interactions of external and internal factors and diverse cell types, we believe that these methods can be used to understand carcinogenesis from a different perspective.

Introduction:High-linear energy transfer (LET) radiation such as carbon ions exhibits greater biological effectiveness than conventional low-LET X-rays, but the transcriptional mechanisms underlying this advantage remain incompletely understood. We hypothesized that high-LET radiation induces a qualitatively different transcriptional response rather than simply amplifying low-LET signaling. Methods:A549 non-small cell lung cancer cells were exposed to equal physical doses (8 Gy) of X-rays or carbon ions (LET 73 keV/µm), and transcriptomic profiling was performed 4 h post-irradiation. Differential expression analysis was integrated with Hallmark pathway enrichment using gene set enrichment analysis (GSEA), over-representation analysis (ORA), and leading-edge gene interrogation to identify shared and LET-dependent gene expression regulation. Results:Both radiation modalities activated a conserved DNA damage response characterized by p53 signaling and apoptosis-related genes. In contrast, carbon ions selectively suppressed mitotic regulators including CENPE, KIF2C, PLK1, and BUB1, consistent with transcriptional disruption of the replication-segregation machinery. High-LET irradiation additionally enriched inflammatory and stress-associated pathways, including tumor necrosis factor (TNF), Nuclear Factor κB (NF-κB) and extracellular matrix and adhesion-related signatures annotated within the Hallmark epithelial-mesenchymal transition (EMT) gene set. Carbon ions also downregulated multiple core and linker histone genes, revealing a chromatin regulatory reprogramming signature although this may reflect modulation of mRNA stability linked to replication stress and cell-cycle progression. KRAS-associated gene networks were enriched under high-LET conditions, reflecting convergence of stress-responsive signaling. Discussion:At equal physical doses, high-LET carbon ion irradiation is associated with a transcriptional program distinct from that of low-LET X-rays, characterized by downregulation of mitotic and chromatin regulatory programs and selective engagement of stress-associated signaling networks. These findings provide mechanistic insight into LET-dependent radiobiology and suggest transcriptional pathway remodeling may contribute to the enhanced biological effectiveness of carbon ions.

Hypoxia-induced radioresistance in non-small cell lung cancer (NSCLC) hinders radiotherapy efficacy. Fractionated schedules exploit reoxygenation between fractions to reverse this resistance, but the effects of post-irradiation reoxygenation remain unclear and may depend on radiation quality. We investigated survival, cell cycle progression, cytokine secretion, and gene expression in hypoxic (1 % O2) and reoxygenated A549 cells irradiated with X-rays or carbon ions. Colony-forming assays revealed an Oxygen Enhancement Ratio (OER) > 1 for both hypoxic and reoxygenated cells after X-rays, indicating persistent radioresistance; carbon ion OER ≈ 1 reflected oxygen-independent cytotoxicity. Hypoxia weakened radiation-induced G2 arrest, and this was unaffected by reoxygenation. IL-6 secretion increased after X-rays and IL-8 after carbon ions exposure; both were enhanced under hypoxia and reoxygenation. RNA sequencing revealed that hypoxia induced a pro-survival, epithelial-to-mesenchymal transition (EMT)-promoting, and immune-evasive transcriptional program, which was largely reversed by reoxygenation but without increased clonogenic killing. These findings indicate that short-term reoxygenation after irradiation can normalize hypoxia-driven transcriptional changes yet does not restore radiosensitivity, supporting the advantage of high-linear energy transfer (LET) carbon ions for targeting resistant hypoxic NSCLC cells.

Progress in mechanobiology allowed us to better understand the important role of mechanical forces in the regulation of biological processes. Space research in the field of life sciences clearly showed that gravity plays a crucial role in biological processes. The space environment offers the unique opportunity to carry out experiments without gravity, helping us not only to understand the effects of gravitational alterations on biological systems but also the mechanisms underlying mechanoperception and cell/tissue response to mechanical and gravitational stresses. Despite the progress made so far, for future space exploration programs it is necessary to increase our knowledge on the mechanotransduction processes as well as on the molecular mechanisms underlying microgravity-induced cell and tissue alterations. This white paper reports the suggestions and recommendations of the SciSpacE Science Community for the elaboration of the section of the European Space Agency roadmap “Biology in Space and Analogue Environments” focusing on “How are cells and tissues influenced by gravity and what are the gravity perception mechanisms?” The knowledge gaps that prevent the Science Community from fully answering this question and the activities proposed to fill them are discussed.

Periodically, the European Space Agency (ESA) updates scientific roadmaps in consultation with the scientific community. The ESA SciSpacE Science Community White Paper (SSCWP) 9, "Biology in Space and Analogue Environments", focusses in 5 main topic areas, aiming to address key community-identified knowledge gaps in Space Biology. Here we present one of the identified topic areas, which is also an unanswered question of life science research in Space: "How to Obtain an Integrated Picture of the Molecular Networks Involved in Adaptation to Microgravity in Different Biological Systems?" The manuscript reports the main gaps of knowledge which have been identified by the community in the above topic area as well as the approach the community indicates to address the gaps not yet bridged. Moreover, the relevance that these research activities might have for the space exploration programs and also for application in industrial and technological fields on Earth is briefly discussed.

Cellular hypoxia, detectable in up to 80% of non-small cell lung carcinoma (NSCLC) tumors, is a known cause of radioresistance. High linear energy transfer (LET) particle radiation might be effective in the treatment of hypoxic solid tumors, including NSCLC. Cellular hypoxia can activate nuclear factor κB (NF-κB), which can modulate radioresistance by influencing cancer cell survival. The effect of high-LET radiation on NF-κB activation in hypoxic NSCLC cells is unclear. Therefore, we compared the effect of low (X-rays)- and high (12C)-LET radiation on NF-κB responsive genes’ upregulation, as well as its target cytokines’ synthesis in normoxic and hypoxic A549 NSCLC cells. The cells were incubated under normoxia (20% O2) or hypoxia (1% O2) for 48 h, followed by irradiation with 8 Gy X-rays or 12C ions, maintaining the oxygen conditions until fixation or lysis. Regulation of NF-κB responsive genes was evaluated by mRNA sequencing. Secretion of NF-κB target cytokines, IL-6 and IL-8, was quantified by ELISA. A greater fold change increase in expression of NF-κB target genes in A549 cells following exposure to 12C ions compared to X-rays was observed, regardless of oxygenation status. These genes regulate cell migration, cell cycle, and cell survival. A greater number of NF-κB target genes was activated under hypoxia, regardless of irradiation status. These genes regulate cell migration, survival, proliferation, and inflammation. X-ray exposure under hypoxia additionally upregulated NF-κB target genes modulating immunosurveillance and epithelial-mesenchymal transition (EMT). Increased IL-6 and IL-8 secretion under hypoxia confirmed NF-κB-mediated expression of pro-inflammatory genes. Therefore, radiotherapy, particularly with X-rays, may increase tumor invasiveness in surviving hypoxic A549 cells.

As humans advance their presence in space and seek to improve the quality of life on Earth, a variety of science questions in support of these two objectives can be answered using the Moon. In this paper, we present a concept for an integrated mission focused on answering fundamental and applied biological questions on the Moon: BioMoon. The mission was designed to investigate the effects of the lunar radiation, gravity, and regolith on biological systems ranging from biomolecules to systems with complex trophic interactions, spanning a range of model organisms. Using common analytical systems and data processing, BioMoon represents a systems-level integrated life sciences mission. It would provide fundamental insights into biological responses to the lunar environment, as well as applied knowledge for In-Situ Resource Utilisation (ISRU), closed-loop life support system development, planetary protection and human health care. The mission was conceived to test biotechnology and sensor technology for lunar and terrestrial application and provide education and outreach opportunities. Although BioMoon was considered in the context of the European Space Agency’s Argonaut (European Large Logistics Lander) concept, the mission design provides a template for any integrated life sciences experimental suite on the Moon and other celestial bodies, implemented either robotically or by human explorers.

Hypoxia-induced radioresistance limits therapeutic success in cancer. In addition, p53 mutations are widespread in tumors including non-small cell lung carcinomas (NSCLCs), and they might modify the radiation response of hypoxic tumor cells. We therefore analyzed the DNA damage and inflammatory response in chronically hypoxic (1% O2, 48 h) p53 null H358 NSCLC cells after X-ray exposure. We used the colony-forming ability assay to determine cell survival, γH2AX immunofluorescence microscopy to quantify DNA double-strand breaks (DSBs), flow cytometry of DAPI-stained cells to measure cell cycle distribution, ELISAs to quantify IL-6 and IL-8 secretion in cell culture supernatants, and RNA sequencing to determine gene expression. Chronic hypoxia increased the colony-forming ability and radioresistance of H358 cells. It did not affect the formation or resolution of X-ray-induced DSBs. It reduced the fraction of cells undergoing G2 arrest after X-ray exposure and delayed the onset of G2 arrest. Hypoxia led to an earlier enhancement in cytokines secretion rate after X-irradiation compared to normoxic controls. Gene expression changes were most pronounced after the combined exposure to hypoxia and X-rays and pertained to senescence and different cell death pathways. In conclusion, hypoxia-induced radioresistance is present despite the absence of functional p53. This resistance is related to differences in clonogenicity, cell cycle regulation, cytokine secretion, and gene expression under chronic hypoxia, but not to differences in DNA DSB repair kinetics.

Hypoxia-induced radioresistance reduces the efficacy of radiotherapy for solid malignancies, including non-small cell lung cancer (NSCLC). Cellular hypoxia can confer radioresistance through cellular and tumor micro-environment adaptations. Until recently, studies evaluating radioresistance secondary to hypoxia were designed to maintain cellular hypoxia only before and during irradiation, while any handling of post-irradiated cells was carried out in standard oxic conditions due to the unavailability of hypoxia workstations. This limited the possibility of simulating in vivo or clinical conditions in vitro. The presence of molecular oxygen is more important for the radiotoxicity of low-linear energy transfer (LET) radiation (e.g., X-rays) than that of high-LET carbon (12C) ions. The mechanisms responsible for 12C ions’ potential to overcome hypoxia-induced radioresistance are currently not fully understood. Therefore, the radioresistance of hypoxic A549 NSCLC cells following exposure to X-rays or 12C ions was investigated along with cell cycle progression and gene expression by maintaining hypoxia before, during and after irradiation. A549 cells were incubated under normoxia (20% O2) or hypoxia (1% O2) for 48 h and then irradiated with X-rays (200 kV) or 12C ions (35 MeV/n, LET ~75 keV/µm). Cell survival was evaluated using colony-forming ability (CFA) assays immediately or 24 h after irradiation (late plating). DNA double-strand breaks (DSBs) were analyzed using γH2AX immunofluorescence microscopy. Cell cycle progression was determined by flow cytometry of 4′,6-diamidino-2-phenylindole-stained cells. The global transcription profile post-irradiation was evaluated by RNA sequencing. When hypoxia was maintained before, during and after irradiation, hypoxia-induced radioresistance was observed only in late plating CFA experiments. The killing efficiency of 12C ions was much higher than that of X-rays. Cell survival under hypoxia was affected more strongly by the timepoint of plating in the case of X-rays compared to 12C ions. Cell cycle arrest following irradiation under hypoxia was less pronounced but more prolonged. DSB induction and resolution following irradiation were not significantly different under normoxia and hypoxia. Gene expression response to irradiation primarily comprised cell cycle regulation for both radiation qualities and oxygen conditions. Several PI3K target genes involved in cell migration and cell motility were differentially upregulated in hypoxic cells. Hypoxia-induced radioresistance may be linked to altered cell cycle response to irradiation and PI3K-mediated changes in cell motility and migration in A549 cells rather than less DNA damage or faster repair.

Space radiation is a notable hazard for long-duration human spaceflight1. Associated risks include cancer, cataracts, degenerative diseases2 and tissue reactions from large, acute exposures3. Space radiation originates from diverse sources, including galactic cosmic rays4, trapped-particle (Van Allen) belts5 and solar-particle events6. Previous radiation data are from the International Space Station and the Space Shuttle in low-Earth orbit protected by heavy shielding and Earth's magnetic field7,8 and lightly shielded interplanetary robotic probes such as Mars Science Laboratory and Lunar Reconnaissance Orbiter9,10. Limited data from the Apollo missions11-13 and ground measurements with substantial caveats are also available14. Here we report radiation measurements from the heavily shielded Orion spacecraft on the uncrewed Artemis I lunar mission. At differing shielding locations inside the vehicle, a fourfold difference in dose rates was observed during proton-belt passes that are similar to large, reference solar-particle events. Interplanetary cosmic-ray dose equivalent rates in Orion were as much as 60% lower than previous observations9. Furthermore, a change in orientation of the spacecraft during the proton-belt transit resulted in a reduction of radiation dose rates of around 50%. These measurements validate the Orion for future crewed exploration and inform future human spaceflight mission design.

IntroductionExposure to space conditions during crewed long-term exploration missions can cause several health risks for astronauts. Space radiation, isolation and microgravity are major limiting factors. The role of astrocytes in cognitive disturbances by space radiation is unknown. Astrocytes' response toward low linear energy transfer (LET) X-rays and high-LET carbon (12C) and iron (56Fe) ions was compared to reveal possible effects of space-relevant high-LET radiation. Since astronauts are exposed to ionizing radiation and microgravity during space missions, the effect of simulated microgravity on DNA damage induction and repair was investigated.MethodsPrimary murine cortical astrocytes were irradiated with different doses of X-rays, 12C and 56Fe ions at the heavy ion accelerator GSI. DNA damage and repair (γH2AX, 53BP1), cell proliferation (Ki-67), astrocytes' reactivity (GFAP) and NF-κB pathway activation (p65) were analyzed by immunofluorescence microscopy. Cell cycle progression was investigated by flow cytometry of DNA content. Gene expression changes after exposure to X- rays were investigated by mRNA-sequencing. RT-qPCR for several genes of interest was performed with RNA from X-rays- and heavy-ion-irradiated astrocytes: Cdkn1a, Cdkn2a, Gfap, Tnf, Il1β, Il6, and Tgfβ1. Levels of the pro inflammatory cytokine IL-6 were determined using ELISA. DNA damage response was investigated after exposure to X-rays followed by incubation on a 2D clinostat to simulate the conditions of microgravity.ResultsAstrocytes showed distinct responses toward the three different radiation qualities. Induction of radiation-induced DNA double strand breaks (DSBs) and the respective repair was dose-, LET- and time-dependent. Simulated microgravity had no significant influence on DNA DSB repair. Proliferation and cell cycle progression was not affected by radiation qualities examined in this study. Astrocytes expressed IL-6 and GFAP with constitutive NF-κB activity independent of radiation exposure. mRNA sequencing of X-irradiated astrocytes revealed downregulation of 66 genes involved in DNA damage response and repair, mitosis, proliferation and cell cycle regulation.DiscussionIn conclusion, primary murine astrocytes are DNA repair proficient irrespective of radiation quality. Only minor gene expression changes were observed after X-ray exposure and reactivity was not induced. Co-culture of astrocytes with microglial cells, brain organoids or organotypic brain slice culture experiments might reveal whether astrocytes show a more pronounced radiation response in more complex network architectures in the presence of other neuronal cell types.

Hypoxia occurs in 80% of non-small cell lung carcinoma (NSCLC) cases, leading to treatment resistance. Hypoxia’s effects on NSCLC energetics are not well-characterized. We evaluated changes in glucose uptake and lactate production in two NSCLC cell lines under hypoxia in conjunction with growth rate and cell cycle phase distribution. The cell lines A549 (p53 wt) and H358 (p53 null) were incubated under hypoxia (0.1% and 1% O2) or normoxia (20% O2). Glucose and lactate concentrations in supernatants were measured using luminescence assays. Growth kinetics were followed over seven days. Cell nuclei were stained with DAPI and nuclear DNA content was determined by flow cytometry to determine cell cycle phase. Gene expression under hypoxia was determined by RNA sequencing. Glucose uptake and lactate production under hypoxia were greater than under normoxia. They were also significantly greater in A549 compared to H358 cells. Faster energy metabolism in A549 cells was associated with a higher growth rate in comparison to H358 cells under both normoxia and hypoxia. In both cell lines, hypoxia significantly slowed down the growth rate compared to proliferation under normoxic conditions. Hypoxia led to redistribution of cells in the different cycle phases: cells in G1 increased and the G2 population decreased. Glucose uptake and lactate production increase under hypoxia in NSCLC cells indicated greater shunting of glucose into glycolysis rather than into oxidative phosphorylation compared to normoxia, making adenosine triphosphate (ATP) production less efficient. This may explain the redistribution of hypoxic cells in the G1 cell cycle phase and the time increase for cell doubling. Energy metabolism changes were more prominent in faster-growing A549 cells compared to slower-growing H358 cells, indicating possible roles for the p53 status and inherent growth rate of different cancer cells. In both cell lines, genes associated with cell motility, locomotion and migration were upregulated under chronic hypoxia, indicating a strong stimulus to escape hypoxic conditions.

HomeCirculation ResearchVol. 132, No. 9Hypoxia and Cardiac Function in Patients With Prior Myocardial Infarction Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBHypoxia and Cardiac Function in Patients With Prior Myocardial Infarction Jan-Niklas Hönemann, Darius Gerlach, Fabian Hoffmann, Tilmann Kramer, Henning Weis, Christine E. Hellweg, Bikash Konda, Vlad G. Zaha, Hesham A. Sadek, Antonius E. van Herwarden, André J. Olthaar, Hannes Reuter, Stephan Baldus, Benjamin D. Levine, Jens Jordan, Jens Tank and Ulrich Limper Jan-Niklas HönemannJan-Niklas Hönemann https://orcid.org/0000-0001-6261-1446 Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care (J.-N.H., F.H., T.K., S.B.), University of Cologne, Germany. German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). , Darius GerlachDarius Gerlach https://orcid.org/0000-0001-7044-6065 German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). , Fabian HoffmannFabian Hoffmann https://orcid.org/0000-0002-3199-9924 Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care (J.-N.H., F.H., T.K., S.B.), University of Cologne, Germany. German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). , Tilmann KramerTilmann Kramer https://orcid.org/0000-0003-0265-7607 Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care (J.-N.H., F.H., T.K., S.B.), University of Cologne, Germany. German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). , Henning WeisHenning Weis https://orcid.org/0000-0001-8638-3281 Department of Nuclear Medicine, Faculty of Medicine and University Hospital Cologne (H.W.), University of Cologne, Germany. German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). , Christine E. HellwegChristine E. Hellweg https://orcid.org/0000-0002-2223-3580 German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). , Bikash KondaBikash Konda German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). , Vlad G. ZahaVlad G. Zaha https://orcid.org/0000-0003-4878-891X Division of Cardiology, Department of Internal Medicine (V.G.Z., H.A.S., B.D.L.), UT Southwestern Medical Center, Dallas, TX. Advanced Imaging Research Center (V.G.Z.), UT Southwestern Medical Center, Dallas, TX. , Hesham A. SadekHesham A. Sadek https://orcid.org/0000-0002-4745-366X Division of Cardiology, Department of Internal Medicine (V.G.Z., H.A.S., B.D.L.), UT Southwestern Medical Center, Dallas, TX. Center for Regenerative Science and Medicine (H.A.S.), UT Southwestern Medical Center, Dallas, TX. , Antonius E. van HerwardenAntonius E. van Herwarden Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands (A.E.v.H., A.J.O.). , André J. OlthaarAndré J. Olthaar Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands (A.E.v.H., A.J.O.). , Hannes ReuterHannes Reuter Cardiology Department, EVK Weyertal, Cologne, Germany (H.R.). , Stephan BaldusStephan Baldus https://orcid.org/0000-0001-8259-1737 Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care (J.-N.H., F.H., T.K., S.B.), University of Cologne, Germany. , Benjamin D. LevineBenjamin D. Levine https://orcid.org/0000-0001-9064-7251 Division of Cardiology, Department of Internal Medicine (V.G.Z., H.A.S., B.D.L.), UT Southwestern Medical Center, Dallas, TX. Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (B.D.L.). , Jens JordanJens Jordan https://orcid.org/0000-0003-4518-0706 German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). Head of Aerospace Medicine, University of Cologne, Germany (J.J.). , Jens TankJens Tank Correspondence to: Jens Tank, MD, Institute of Aerospace Medicine, Linder Hoehe, 51147 Cologne, Germany. Email E-mail Address: [email protected] https://orcid.org/0000-0002-5672-1187 German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). and Ulrich LimperUlrich Limper https://orcid.org/0000-0001-9927-4180 German Aerospace Center, Institute of Aerospace Medicine, Cologne, Germany (J.-N.H., D.G., F.H., T.K., H.W., C.E.H., B.K., J.J., J.T., U.L.). Department of Anesthesiology and Intensive Care Medicine, Merheim Medical Center, Hospitals of Cologne, University of Witten/Herdecke, Germany (U.L.). Originally published3 Apr 2023https://doi.org/10.1161/CIRCRESAHA.122.322334Circulation Research. 2023;132:1165–1167is related toMeet the First AuthorsOther version(s) of this articleYou are viewing the most recent version of this article. Previous versions: April 3, 2023: Ahead of Print In mice with experimental myocardial infarction, sustained normobaric hypoxia corresponding to 8000 m altitude improves myocardial regeneration and left ventricular (LV) function likely by reducing oxidative DNA damage.1 Hypoxia-induced pulmonary hypertension or myocardial ischemia could limit translation to patients. We tested the feasibility and safety of exposing highly selected patients with previous myocardial infarction to normobaric hypoxia corresponding to ≈4500 m altitude for 4.5 days. We evaluated hypoxia influences on LV function and DNA repair in peripheral blood mononuclear cells (PBMCs).2Meet the First Author, see p 1103We recruited patients with previous myocardial infarction, fully revascularized LAD lesions, no angina pectoris, or cardiac decompensation in the past 12 months who were otherwise healthy, physically fit, and had previously tolerated >2000 m altitude. The local ethics committee approved the study.In the German Aerospace Center (DLR):envihab hypoxia module, we decreased the fraction of inspired oxygen (FIO2) stepwise by adding nitrogen over 14 days, maintained 0.118 FIO2 for 4.5 days (hypoxia), and returned normoxia (Figure [A]). We obtained transthoracic echocardiograms on the second acclimatization day and daily at 0.118 FIO2 and during the first 2 recovery days at 0.209 FIO2 to assess right ventricular anatomy, tricuspid annular plane systolic excursion, biplane LV ejection fraction, LV global longitudinal strain, and systolic pulmonary artery pressure. We acquired short-axis real-time cardiac magnetic resonance imaging at 33 ms temporal resolution during spontaneous breathing for 9.9 s per slice3 at baseline, 0.118 FIO2, and early recovery. We obtained venous blood samples for cardiovascular biomarker and catecholamine measurements. We examined ex vivo DNA repair by exposing PBMCs isolated from all patients at baseline, during hypoxia, and during recovery to 1G X-Ray irradiation and assessed cells for DNA double-strand break repair while maintaining oxygen conditions ex vivo.Download figureDownload PowerPointFigure. Schedule and results of the hypoxia study. A, Fraction of inspired oxygen (FIO2) and corresponding altitude equivalents in meters over time. 0.118 FIO2 level was maintained during daytime and was increased to 0.148 FIO2 during nighttime to ameliorate sleep and acute mountain sickness symptoms. B, Peripheral blood mononuclear cells (PBMCs) were isolated during normoxia, hypoxia (11.8%), and recovery from blood samples that were taken from the subjects on days 1, 16, and 21 (second day of recovery) of this study, irradiated ex vivo with radiographs and incubated after irradiation to investigate the effects of atmospheric oxygen on DNA double-strand break induction and repair at the cellular level by flow cytometric analysis using γ-H2AX (phosphorylated Ser-139 residue of the histone variant H2AX), which indicates cells with DNA double-strand breaks. The oxygen concentrations were maintained until fixation of PBMCs. The percentage of cells with unrepaired DNA during hypoxia decreased significantly compared with normoxia (Friedman test, n=4). C, Central findings of the study (mean±SD, n=4). Magnetic resonance imaging (MRI) data were obtained in a blinded analysis; echocardiographic-derived findings were nonblinded for reasons of safety. All subjects were under standard medical therapy following their myocardial infarctions (2/4 aspirin, 1/4 marcumar, 1/4 anti-Xa-antagonist, 4/4 statin, 4/4 ACE (angiotensin-converting enzyme) inhibitor/AT1 (angiotensin type 1 receptor) antagonist, 1/4 azetidinone, 1/4 β-blockers, and 1/4 dihydropiyridine). Left ventricular ejection fraction (LVEF) increased while LV end systolic volume decreased, which emphasizes a reduction in LV dysfunction. D, Bull's eye of LV global circumferential strain analysis (real-time MRI) in baseline, recovery, and follow-up of the subject with the most pronounced increase of LVEF. Sectoral analysis revealed an increase in viable but also previous hypokinetic areas. NT-proBNP indicates N-terminal pro-B-type natriuretic peptide; and TAPSE, tricuspid annular plane systolic excursion.Of 11 screened patients, we included 4 men (age, 54–63 years;body mass index, 21–25 kg/m2; VO2 max, 32–43 mL/kg per minute) 37 to 104 months following myocardial infarction (3× ST-segment–elevation myocardial infarction, 1× non–ST-segment–elevation myocardial infarction). We excluded 1 woman with thrombocytosis and another woman because of right ventricular involvement. Participants had isolated left anterior descending artery mid-segmental to ostial culprit lesions fully revascularized through interventions and myocardial scars. All received heart failure medications (Figure [C]). At 0.118 FIO2, all participants experienced acute mountain sickness symptoms without signs of cardiac decompensation (Lake Louise Acute Mountain Sickness Score: baseline, 3.25±1.5; hypoxia, 5.25±1.04; recovery, 0.75±0.96 points). Hypoxia-induced pulmonary hypertension rapidly abated in recovery (Figure [C]). Arterial oxygen partial pressure decreased from 94±10 to 51±3 mm Hg. High-sensitivity troponin I was never elevated. Supine plasma norepinephrine was 2.24±0.09 nmol/L at baseline, 5.33±1.55 nmol/L during hypoxia, and 4.01±1.4 nmol/L during recovery.LV ejection fraction was improved during and after hypoxia exposure (P=0.0046, Friedman test, n=4). Echocardiographic-derived global longitudinal LV strain and MRI-derived global circumferential LV strain improved modestly (Figure [C]).In the participant with most impaired cardiac function, LV ejection fraction was 36% at baseline, 44% during hypoxia, 48% at early recovery, and 47% 12 weeks thereafter with corresponding LV strain improvement. He also showed sustained improvement in NT-proBNP (N-terminal pro-B-type natriuretic peptide; baseline, 477 pg/mL; hypoxia, 218 pg/mL; recovery, 174 pg/mL; 12-week follow-up, 229 pg/mL; Figure [D]) and reduced LV end-systolic volume (baseline, 159 mL; hypoxia, 137 mL: recovery, 127 mL; 12-week follow-up, 127 mL; Figure [D]).Ex vivo irradiation massively increased the number of PBMCs with unrepaired DNA damage peaking after 2 hours with subsequent return to baseline due to DNA repair (Figure [B]). The PBMC number with unrepaired DNA damage was reduced during hypoxia and following recovery.Previously, we exposed 2 healthy people (1 man and 1 woman) to sustained hypoxia corresponding to ≈7000 m altitude.4 In contrast to our patients with myocardial infarction, hypoxia exposure did not augment LV ejection fraction measured by cardiac cine MRI (baseline, 68.7±2.8; recovery, 64.1±0.38).We exposed fully revascularized, physical active patients with prior myocardial infarction to substantial normobaric hypoxia (peripheral oxygen saturation [SpO2], <90%) over about 10 days while monitoring cardiac function. Despite reversible increases in pulmonary artery pressure, patients did not experience myocardial ischemia or worsened cardiac function during hypoxia. LV function and NT-proBNP tended to improve following hypoxia exposure. The response could be mediated through augmented contractility in viable myocardium or through improved function or myocardial regeneration in or around the myocardial scar. Transiently increased norepinephrine release during hypoxia is unlikely to explain sustained contractility improvements following cessation of hypoxia.An improved DNA damage response in PBMCs might suggest that hypoxia may have engaged potentially favorable molecular pathways but cannot be simply extrapolated to myocardial cells. Our findings encourage validation in human cardiomyocytes to further explore cross talk between DNA damage response and LV remodeling.5 The small sample size, relatively short hypoxia period,1 inclusion of male patients only, and the highly selected patient population are important limitations. Nevertheless, our study lays the foundation for future studies assessing influences of more severe and sustained hypoxia on cardiac regeneration in human beings.Article InformationAcknowledgmentsWe thank Jens Frahm (Max Planck Institute for Multidisciplinary Sciences, Goettingen, Germany) and his team for the support in establishing real-time cardiac magnetic resonance imaging. REGISTRATION: Unique Identifier: DRKS00013772 (https://drks.de/search/en/trial/DRKS00013772).Data AvailabilityData are available through https://doi.org/10.5281/zenodo.5910897.Sources of FundingThe study was conducted with programmatic support of the German Aerospace Center.Non-Standard AbbreviationsFIO2fraction of inspired oxygenLVleft ventricularPBMCperipheral blood mononuclear cellsDisclosures J. Jordan has served as a consultant for Novartis, Boehringer Ingelheim, and Novo-Nordisk and is a cofounder of Eternygen GmbH (modest relationship). J. Tank received funding from Boston Scientific, Boehringer Ingelheim, and Novo-Nordisk. U. Limper was supported by the Faculty of Health of the University of Witten/Herdecke internal grant program (project IFF 2020-26). J.-N. Hönemann and F. Hoffmann received funding from the German Aerospace Center and the German Federal Ministry of Industry and Technology (BMWK, 50WB1517 and 50WB1816). The other authors report no conflicts.Footnotes*J.-N. Hönemann, D. Gerlach, J. Tank, and U. Limper contributed equally.For Sources of Funding and Disclosures, see page 1167.Correspondence to: Jens Tank, MD, Institute of Aerospace Medicine, Linder Hoehe, 51147 Cologne, Germany. Email jens.tank@dlr.deReferences1. Nakada Y, Canseco DC, Thet S, Abdisalaam S, Asaithamby A, Santos CX, Shah AM, Zhang H, Faber JE, Kinter MT, et al. Hypoxia induces heart regeneration in adult mice.Nature. 2017; 541:222–227. doi: 10.1038/nature20173CrossrefMedlineGoogle Scholar2. Sedelnikova OA, Rogakou EP, Panyutin IG, Bonner WM. Quantitative detection of (125)IdU-induced DNA double-strand breaks with gamma-H2AX antibody.Radiat Res. 2002; 158:486–492. doi: 10.1667/0033-7587(2002)158[0486:qdoiid]2.0.co;2CrossrefMedlineGoogle Scholar3. Uecker M, Zhang S, Frahm J. Nonlinear inverse reconstruction for real-time MRI of the human heart using undersampled radial FLASH.Magn Reson Med. 2010; 63:1456–1462. doi: 10.1002/mrm.22453CrossrefMedlineGoogle Scholar4. Hoffmann F, Limper U, Zaha VG, Reuter H, Zange L, Schulz-Menger J, Hein M, Baldus S, Levine BD, Jordan J, et al. Evolution of pulmonary hypertension during severe sustained hypoxia.Circulation. 2020; 141:1504–1506. doi: 10.1161/CIRCULATIONAHA.119.045192LinkGoogle Scholar5. Wu L, Sowers JR, Zhang Y, Ren J. Targeting DNA damage response in cardiovascular diseases: from pathophysiology to therapeutic implications.Cardiovasc Res. 2022:cvac080. doi: 10.1093/cvr/cvac080CrossrefMedlineGoogle Scholar eLetters(0) eLetters should relate to an article recently published in the journal and are not a forum for providing unpublished data. Comments are reviewed for appropriate use of tone and language. Comments are not peer-reviewed. Acceptable comments are posted to the journal website only. Comments are not published in an issue and are not indexed in PubMed. Comments should be no longer than 500 words and will only be posted online. References are limited to 10. Authors of the article cited in the comment will be invited to reply, as appropriate. Comments and feedback on AHA/ASA Scientific Statements and Guidelines should be directed to the AHA/ASA Manuscript Oversight Committee via its Correspondence page. Sign In to Submit a Response to This Article Previous Back to top Next FiguresReferencesRelatedDetailsCited By Kramer T, Hoenemann J, Weis H, Hoffmann F, Rosenkranz S, Baldus S, Hellmich M, Levine B, Jordan J, Tank J and Limper U (2023) Electrocardiographic changes during sustained normobaric hypoxia in patients after myocardial infarction, Scientific Reports, 10.1038/s41598-023-43707-5, 13:1 Related articlesMeet the First AuthorsCirculation Research. 2023;132:1102-1103 April 28, 2023Vol 132, Issue 9 Advertisement Article Information Metrics © 2023 American Heart Association, Inc.https://doi.org/10.1161/CIRCRESAHA.122.322334PMID: 37009742 Originally publishedApril 3, 2023 Keywordsaltitudeheart failurehypoxiamyocardial infarctiontranslational sciencebiomedicalPDF download Advertisement Subjects Chronic Ischemic Heart Disease

The Artificial Gravity Bed Rest - European Space Agency (AGBRESA) study was the first joint bed rest study by ESA, DLR, and NASA that examined the effect of simulated weightlessness on the human body and assessed the potential benefits of artificial gravity as a countermeasure in an analog of long-duration spaceflight. In this study, we investigated the impact of simulated microgravity on the gut microbiome of 12 participants during a 60-day head-down tilt bed rest at the :envihab facilities. Over 60 days of simulated microgravity resulted in a mild change in the gut microbiome, with distinct microbial patterns and pathway expression in the feces of the countermeasure group compared to the microgravity simulation-only group. Additionally, we found that the countermeasure protocols selectively increased the abundance of beneficial short-chain fatty acids in the gut, such as acetate, butyrate, and propionate. Some physiological signatures also included the modulation of taxa reported to be either beneficial or opportunistic, indicating a mild adaptation in the microbiome network balance. Our results suggest that monitoring the gut microbial catalog along with pathway clustering and metabolite profiling is an informative synergistic strategy to determine health disturbances and the outcome of countermeasure protocols for future space missions. The future of spaceflight will involve missions beyond the International Space Station or the Moon and astronaut's health will be challenged by a harsh space environment for longer periods. In the last decade, the intestine has gained importance in dictating overall physiology and we explore it as an additional indicator of health during our ground-based bed rest study simulating microgravity for 60 days. Through the analysis of fecal proteins, we compile the catalog of microbes colonizing the gut of the 12 participants along with the implicated biological activity of the proteins and another 9 lipid analytes. We found specific microbes associated with recovery or healthy status in our subjects to be increased during spaceflight countermeasure conditions and inverse observations in subjects subjected to perilous spaceflight simulation. Our approach improves the functional characterization of the gut by the use of noninvasive methodology correlating the microbial composition of human stool samples with physiological status.

The present white paper concerns the indications and recommendations of the SciSpacE Science Community to make progress in filling the gaps of knowledge that prevent us from answering the question: “How Do Gravity Alterations Affect Animal and Human Systems at a Cellular/Tissue Level?” This is one of the five major scientific issues of the ESA roadmap “Biology in Space and Analogue Environments”. Despite the many studies conducted so far on spaceflight adaptation mechanisms and related pathophysiological alterations observed in astronauts, we are not yet able to elaborate a synthetic integrated model of the many changes occurring at different system and functional levels. Consequently, it is difficult to develop credible models for predicting long-term consequences of human adaptation to the space environment, as well as to implement medical support plans for long-term missions and a strategy for preventing the possible health risks due to prolonged exposure to spaceflight beyond the low Earth orbit (LEO). The research activities suggested by the scientific community have the aim to overcome these problems by striving to connect biological and physiological aspects in a more holistic view of space adaptation effects.

AbstractThe study of the biologic effects of space radiation is considered a “hot topic,” with increased interest in the past years. In this chapter, the unique characteristics of the space radiation environment will be covered, from their history, characterization, and biological effects to the research that has been and is being conducted in the field.After a short introduction, you will learn the origin and characterization of the different types of space radiation and the use of mathematical models for the prediction of the radiation doses during different mission scenarios and estimate the biological risks due to this exposure. Following this, the acute, chronic, and late effects of radiation exposure in the human body are discussed before going into the detailed biomolecular changes affecting cells and tissues, and in which ways they differ from other types of radiation exposure.The next sections of this chapter are dedicated to the vast research that has been developed through the years concerning space radiation biology, from small animals to plant models and 3D cell cultures, the use of extremophiles in the study of radiation resistance mechanisms to the importance of ground-based irradiation facilities to simulate and study the space environment.

Human spaceflight is entering a new era of sustainable human space exploration. By 2030 humans will regularly fly to the Moon’s orbit, return to the Moon’s surface and preparations for crewed Mars missions will intensify. In planning these undertakings, several challenges will need to be addressed in order to ensure the safety of astronauts during their space travels. One of the important challenges to overcome, that could be a major showstopper of the space endeavor, is the exposure to the space radiation environment. There is an urgent need for quantifying, managing and limiting the detrimental health risks and electronics damage induced by space radiation exposure. Such risks raise key priority topics for space research programs. Risk limitation involves obtaining a better understanding of space weather phenomena and the complex radiation environment in spaceflight, as well as developing and applying accurate dosimetric instruments, understanding related short- and long-term health risks, and strategies for effective countermeasures to minimize both exposure to space radiation and the remaining effects post exposure. The ESA/SciSpacE Space Radiation White Paper identifies those topics and underlines priorities for future research and development, to enable safe human and robotic exploration of space beyond Low Earth Orbit.

The neuroblastoma cell line SH-SY5Y has been a well-established and very popular in vitro model in neuroscience for decades, especially focusing on neurodevelopmental disorders, such as Parkinson’s disease. The ability of this cell type to differentiate compared with other models in neurobiology makes it one of the few suitable models without having to rely on a primary culture of neuronal cells. Over the years, various, partly contradictory, methods of cultivation have been reported. This study is intended to provide a comprehensive guide to the in vitro cultivation of undifferentiated SH-SY5Y cells. For this purpose, the morphology of the cell line and the differentiation of the individual subtypes are described, and instructions for cell culture practice and long-term cryoconservation are provided. We describe the key growth characteristics of this cell line, including proliferation and confluency data, optimal initial seeding cell numbers, and a comparison of different culture media and cell viability during cultivation. Furthermore, applying an optimized protocol in a long-term cultivation over 60 days, we show that cumulative population doubling (CPD) is constant over time and does not decrease with incremental passage, enabling stable cultivation, for example, for recurrent differentiation to achieve the highest possible reproducibility in subsequent analyses. Therefore, we provide a solid guidance for future research that employs the neuroblastoma cell line SH-SY5Y.

Ionizing radiation (IR) is a genuine genotoxic agent and a major modality in cancer treatment. IR disrupts DNA sequences and exerts mutagenic and/or cytotoxic properties that not only alter critical cellular functions but also impact tissues proximal and distal to the irradiated site. Unveiling the molecular events governing the diverse effects of IR at the cellular and organismal levels is relevant for both radiotherapy and radiation protection. Herein, we address changes in the expression of mammalian genes induced after the exposure of a wide range of tissues to various radiation types with distinct biophysical characteristics. First, we constructed a publicly available database, termed RadBioBase, which will be updated at regular intervals. RadBioBase includes comprehensive transcriptomes of mammalian cells across healthy and diseased tissues that respond to a range of radiation types and doses. Pertinent information was derived from a hybrid analysis based on stringent literature mining and transcriptomic studies. An integrative bioinformatics methodology, including functional enrichment analysis and machine learning techniques, was employed to unveil the characteristic biological pathways related to specific radiation types and their association with various diseases. We found that the effects of high linear energy transfer (LET) radiation on cell transcriptomes significantly differ from those caused by low LET and are consistent with immunomodulation, inflammation, oxidative stress responses and cell death. The transcriptome changes also depend on the dose since low doses up to 0.5 Gy are related with cytokine cascades, while higher doses with ROS metabolism. We additionally identified distinct gene signatures for different types of radiation. Overall, our data suggest that different radiation types and doses can trigger distinct trajectories of cell-intrinsic and cell-extrinsic pathways that hold promise to be manipulated toward improving radiotherapy efficiency and reducing systemic radiotoxicities.

Long term human space missions require efficient strategies to sustain crew health and safety. This is why we need to develop improved spaceflight-suitable methods for microbiological monitoring and contamination control. Especially microbial biofilms are of concern in spaceflight because they can damage equipment by polymer deterioration, corrode metal and cause bio-fouling. Furthermore, biofilms can harbor pathogenic microorganisms that can cause infections which is unwanted, especially since it is known that the immune system of astronauts is impaired during spaceflight. Antimicrobial surfaces reduce the ability of microorganisms to form biofilms and can therefore be helpful in sustaining spaceship integrity as well as the astronaut’s health. Metals such as silver, copper and their alloy are known to have antimicrobial properties. The introduction of antimicrobial surfaces for medical, pharmaceutical and industrial purposes has already shown a unique potential for reducing and preventing microbial contamination. However, their efficiency within the spaceflight context still has to be investigated in further detail: The European Space Agency (ESA) selected project BIOFILMS (No. ILSRA-2014-054) will test the effect of tailor-made nanostructured copper-based surfaces on bacterial biofilm in an experiment aboard the International Space Station (ISS). BIOFILMS is an acronym that stands for “Biofilm Inhibition on Flight equipment and on board the ISS using microbiologically Lethal Metal Surfaces. In the project, three spaceflight relevant bacterial species will be tested: Acinetobacter radioresistens, Cupriavidus metallidurans and Staphylococcus capitis. Steel is going to be used as a refence surface for biofilm formation and the antimicrobial surfaces are copper-based. They differ in their antimicrobial activity based on chemical composition and/or geometric nanostructures. The innovative approach is that the surfaces are patterned in a process called Direct Laser Interference Patterning (DLIP) using ultra-short pulses (USP). The surfaces will be evaluated for biofilm formation rates under different spaceflight relevant gravitational regimes (Mars, ISS and Earth control) and bacterial growth will occur under optimal biofilm-inducing conditions in the KUBIK incubator inside ESA’s Columbus laboratory. Preflight experiments, performed on ground (1g), showed that the BIOFILMS hardware is biocompatible and allows biofilm formation of all three bacterial species on the reference steel surfaces. The use of pure copper and brass surfaces inside the hardware significantly reduced bacterial growth and biofilm formation. In our preliminary experiments, the DLIP nanostructured copper surfaces were more effective than the smooth surfaces. The obtained results from the BIOFILMS experiment will be of immense importance for understanding the influence of gravity on biofilm formation and on the effectivity of USP-DLIP antimicrobial copper surfaces. Furthermore, the evaluation of different antimicrobial materials in microgravity is relevant for present and future astronaut-/robotic-associated activities in space exploration. Here, an overview on the ongoing and upcoming activities of the ISS spaceflight experiment BIOFILMS is presented.