Life | Topical Collection : Space Life Sciences

2024

Jump to: 2022, 2021, 2020

17 pages, 3541 KiB

Open AccessArticle

Infrared Spectroscopy of RNA Nucleosides in a Wide Range of Temperatures

by Susana Iglesias-Groth, Franco Cataldo and Martina Marin-Dobrincic

Life 2024, 14(4), 436; https://doi.org/10.3390/life14040436 - 25 Mar 2024

Viewed by 1230

Abstract

The RNA world hypothesis suggests that early cellular ancestors relied solely on RNA molecules for both genetic information storage and cellular functions. RNA, composed of four nucleosides—adenosine, guanosine, cytidine, and uridine—forms the basis of this theory. These nucleosides consist of purine nucleobases, adenine [...] Read more.

The RNA world hypothesis suggests that early cellular ancestors relied solely on RNA molecules for both genetic information storage and cellular functions. RNA, composed of four nucleosides—adenosine, guanosine, cytidine, and uridine—forms the basis of this theory. These nucleosides consist of purine nucleobases, adenine and guanine, and pyrimidine nucleobases, cytosine and uracil, bonded to ribose sugar. Notably, carbonaceous chondrite meteorites have revealed the presence of these bases and sugar, hinting at the potential existence of nucleosides in space. This study aims to present the infrared spectra of four RNA nucleosides commonly found in terrestrial biochemistry, facilitating their detection in space, especially in astrobiological and astrochemical contexts. Laboratory measurements involved obtaining mid- and far-IR spectra at three temperatures (−180 °C, room temperature, and +180 °C), followed by calculating molar extinction coefficients (ε) and integrated molar absorptivities (ψ) for corresponding bands. These spectral data, along with ε and ψ values, serve to provide quantitative insights into the presence and relative abundance of nucleosides in space and aid in their detection. Full article

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10 pages, 883 KiB

Open AccessArticle

Long-Term Survivability of Tardigrade Paramacrobiotus experimentalis (Eutardigrada) at Increased Magnesium Perchlorate Levels: Implications for Astrobiological Research

by Paulina Anna Wilanowska, Piotr Rzymski and Łukasz Kaczmarek

Life 2024, 14(3), 335; https://doi.org/10.3390/life14030335 - 4 Mar 2024

Cited by 3 | Viewed by 4869 | Correction

Abstract

Perchlorate salts, including magnesium perchlorate, are highly toxic compounds that occur on Mars at levels far surpassing those on Earth and pose a significant challenge to the survival of life on this planet. Tardigrades are commonly known for their extraordinary resistance to extreme [...] Read more.

Perchlorate salts, including magnesium perchlorate, are highly toxic compounds that occur on Mars at levels far surpassing those on Earth and pose a significant challenge to the survival of life on this planet. Tardigrades are commonly known for their extraordinary resistance to extreme environmental conditions and are considered model organisms for space and astrobiological research. However, their long-term tolerance to perchlorate salts has not been the subject of any previous studies. Therefore, the present study aimed to assess whether the tardigrade species Paramacrobiotus experimentalis can survive and grow in an environment contaminated with high levels of magnesium perchlorates (0.10–0.25%, 0.6–1.5 mM ClO₄⁻ ions). The survival rate of tardigrades decreased with an increase in the concentration of the perchlorate solutions and varied from 83.3% (0.10% concentration) to 20.8% (0.25% concentration) over the course of 56 days of exposure. Tardigrades exposed to 0.15–0.25% magnesium perchlorate revealed significantly decreased body length. Our study indicates that tardigrades can survive and grow in relatively high concentrations of magnesium perchlorates, largely exceeding perchlorate levels observed naturally on Earth, indicating their potential use in Martian experiments. Full article

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24 pages, 15626 KiB

Open AccessArticle

Cultivation of Chroococcidiopsis thermalis Using Available In Situ Resources to Sustain Life on Mars

by Giacomo Fais, Mattia Casula, Agnieszka Sidorowicz, Alessia Manca, Valentina Margarita, Pier Luigi Fiori, Antonella Pantaleo, Pierluigi Caboni, Giacomo Cao and Alessandro Concas

Life 2024, 14(2), 251; https://doi.org/10.3390/life14020251 - 13 Feb 2024

Cited by 4 | Viewed by 2623

Abstract

The cultivation of cyanobacteria by exploiting available in situ resources represents a possible way to supply food and oxygen to astronauts during long-term crewed missions on Mars. Here, we evaluated the possibility of cultivating the extremophile cyanobacterium Chroococcidiopsis thermalis CCALA 050 under operating [...] Read more.

The cultivation of cyanobacteria by exploiting available in situ resources represents a possible way to supply food and oxygen to astronauts during long-term crewed missions on Mars. Here, we evaluated the possibility of cultivating the extremophile cyanobacterium Chroococcidiopsis thermalis CCALA 050 under operating conditions that should occur within a dome hosting a recently patented process to produce nutrients and oxygen on Mars. The medium adopted to cultivate this cyanobacterium, named Martian medium, was obtained using a mixture of regolith leachate and astronauts’ urine simulants that would be available in situ resources whose exploitation could reduce the mission payload. The results demonstrated that C. thermalis can grow in such a medium. For producing high biomass, the best medium consisted of specific percentages (40%vol) of Martian medium and a standard medium (60%vol). Biomass produced in such a medium exhibits excellent antioxidant properties and contains significant amounts of pigments. Lipidomic analysis demonstrated that biomass contains strategic lipid classes able to help the astronauts facing the oxidative stress and inflammatory phenomena taking place on Mars. These characteristics suggest that this strain could serve as a valuable nutritional resource for astronauts. Full article

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2022

Jump to: 2024, 2021, 2020

11 pages, 884 KiB

Open AccessConcept Paper

An Electro–Microbial Process to Uncouple Food Production from Photosynthesis for Application in Space Exploration

by Philip J. L. Bell, Ferdinand E. Paras, Sophia Mandarakas, Psyche Arcenal, Sinead Robinson-Cast, Anna S. Grobler and Paul V. Attfield

Life 2022, 12(7), 1002; https://doi.org/10.3390/life12071002 - 6 Jul 2022

Cited by 3 | Viewed by 3805

Abstract

Here we propose the concept of an electro–microbial route to uncouple food production from photosynthesis, thereby enabling production of nutritious food in space without the need to grow plant-based crops. In the proposed process, carbon dioxide is fixed into ethanol using either chemical [...] Read more.

Here we propose the concept of an electro–microbial route to uncouple food production from photosynthesis, thereby enabling production of nutritious food in space without the need to grow plant-based crops. In the proposed process, carbon dioxide is fixed into ethanol using either chemical catalysis or microbial carbon fixation, and the ethanol created is used as a carbon source for yeast to synthesize food for human or animal consumption. The process depends upon technologies that can utilize electrical energy to fix carbon into ethanol and uses an optimized strain of the yeast Saccharomyces cerevisiae to produce high-quality, food-grade, single-cell protein using ethanol as the sole carbon source in a minimal medium. Crops performing photosynthesis require months to mature and are challenging to grow under the conditions found in space, whereas the electro–microbial process could generate significant quantities of food on demand with potentially high yields and productivities. In this paper we explore the potential to provide yeast-based protein and other nutrients relevant to human dietary needs using only ethanol, urea, phosphate, and inorganic salts as inputs. It should be noted that as well as having potential to provide nutrition in space, this novel approach to food production has many valuable terrestrial applications too. For example, by enabling food production in climatically challenged environments, the electro–microbial process could potentially turn deserts into food bowls. Similarly, surplus electricity generated from large-scale renewable power sources could be used to supplement the human food chain. Full article

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19 pages, 2179 KiB

Open AccessReview

Smart Device-Driven Corticolimbic Plasticity in Cognitive-Emotional Restructuring of Space-Related Neuropsychiatric Disease and Injury

by Kevin B. Clark

Life 2022, 12(2), 236; https://doi.org/10.3390/life12020236 - 4 Feb 2022

Cited by 1 | Viewed by 3082

Abstract

Escalating government and commercial efforts to plan and deploy viable manned near-to-deep solar system exploration and habitation over the coming decades now drives next-generation space medicine innovations. The application of cutting-edge precision medicine, such as brain stimulation techniques, provides powerful clinical and field/flight [...] Read more.

Escalating government and commercial efforts to plan and deploy viable manned near-to-deep solar system exploration and habitation over the coming decades now drives next-generation space medicine innovations. The application of cutting-edge precision medicine, such as brain stimulation techniques, provides powerful clinical and field/flight situation methods to selectively control vagal tone and neuroendocrine-modulated corticolimbic plasticity, which is affected by prolonged cosmic radiation exposure, social isolation or crowding, and weightlessness in constricted operational non-terran locales. Earth-based clinical research demonstrates that brain stimulation approaches may be combined with novel psychotherapeutic integrated memory structure rationales for the corrective reconsolidation of arousing or emotional experiences, autobiographical memories, semantic schema, and other cognitive structures to enhance neuropsychiatric patient outcomes. Such smart cotherapies or countermeasures, which exploit natural, pharmaceutical, and minimally invasive neuroprosthesis-driven nervous system activity, may optimize the cognitive-emotional restructuring of astronauts suffering from space-related neuropsychiatric disease and injury, including mood, affect, and anxiety symptoms of any potential severity and pathophysiology. An appreciation of improved neuropsychiatric healthcare through the merging of new or rediscovered smart theragnostic medical technologies, capable of rendering personalized neuroplasticity training and managed psychotherapeutic treatment protocols, will reveal deeper insights into the illness states experienced by astronauts. Future work in this area should emphasize the ethical role of telemedicine and/or digital clinicians to advance the (semi)autonomous, technology-assisted medical prophylaxis, diagnosis, treatment, monitoring, and compliance of astronauts for elevated health, safety, and performance in remote extreme space and extraterrestrial environments. Full article

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2021

Jump to: 2024, 2022, 2020

20 pages, 1510 KiB

Open AccessArticle

Convergent Microbial Community Formation in Replicate Anaerobic Reactors Inoculated from Different Sources and Treating Ersatz Crew Waste

by Lisa M. Steinberg, Amanda J. Martino and Christopher H. House

Life 2021, 11(12), 1374; https://doi.org/10.3390/life11121374 - 10 Dec 2021

Cited by 2 | Viewed by 2496

Abstract

Future manned space travel will require efficient recycling of nutrients from organic waste back into food production. Microbial systems are a low-energy, efficient means of nutrient recycling, but their use in a life support system requires predictability and reproducibility in community formation and [...] Read more.

Future manned space travel will require efficient recycling of nutrients from organic waste back into food production. Microbial systems are a low-energy, efficient means of nutrient recycling, but their use in a life support system requires predictability and reproducibility in community formation and reactor performance. To assess the reproducibility of microbial community formation in fixed-film reactors, we inoculated replicate anaerobic reactors from two methanogenic inocula: a lab-scale fixed-film, plug-flow anaerobic reactor and an acidic transitional fen. Reactors were operated under identical conditions, and we assessed reactor performance and used 16s rDNA amplicon sequencing to determine microbial community formation. Reactor microbial communities were dominated by similar groups, but differences in community membership persisted in reactors inoculated from different sources. Reactor performance overlapped, suggesting a convergence of both reactor communities and organic matter mineralization. The results of this study suggest an optimized microbial community could be preserved and used to start new, or restart failed, anaerobic reactors in a life support system with predictable reactor performance. Full article

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17 pages, 2069 KiB

Open AccessArticle

The Ground-Based BIOMEX Experiment Verification Tests for Life Detection on Mars

by Claudia Pacelli, Alessia Cassaro, Ilaria Catanzaro, Mickael Baqué, Alessandro Maturilli, Ute Böttger, Elke Rabbow, Jean-Pierre Paul de Vera and Silvano Onofri

Life 2021, 11(11), 1212; https://doi.org/10.3390/life11111212 - 9 Nov 2021

Cited by 5 | Viewed by 2960

Abstract

The success of an astrobiological search for life campaign on Mars, or other planetary bodies in the Solar System, relies on the detectability of past or present microbial life traces, namely, biosignatures. Spectroscopic methods require little or no sample preparation, can be repeated [...] Read more.

The success of an astrobiological search for life campaign on Mars, or other planetary bodies in the Solar System, relies on the detectability of past or present microbial life traces, namely, biosignatures. Spectroscopic methods require little or no sample preparation, can be repeated almost endlessly, and can be performed in contact or even remotely. Such methods are therefore ideally suited to use for the detection of biosignatures, which can be confirmed with supporting instrumentation. Here, we discuss the use of Raman and Fourier Transform Infrared (FT-IR) spectroscopies for the detection and characterization of biosignatures from colonies of the fungus Cryomyces antarcticus, grown on Martian analogues and exposed to increasing doses of UV irradiation under dried conditions. The results report significant UV-induced DNA damage, but the non-exceeding of thresholds for allowing DNA amplification and detection, while the spectral properties of the fungal melanin remained unaltered, and pigment detection and identification was achieved via complementary analytical techniques. Finally, this work found that fungal cell wall compounds, likely chitin, were not degraded, and were still detectable even after high UV irradiation doses. The implications for the preservation and detection of biosignatures in extraterrestrial environments are discussed. Full article

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22 pages, 5073 KiB

Open AccessArticle

Spatial Characterization of Microbial Communities on Multi-Species Leafy Greens Grown Simultaneously in the Vegetable Production Systems on the International Space Station

by Mary E. Hummerick, Christina L. M. Khodadad, Anirudha R. Dixit, Lashelle E. Spencer, Gretchen J. Maldonado-Vasquez, Jennifer L. Gooden, Cory J. Spern, Jason A. Fischer, Nicole Dufour, Raymond M. Wheeler, Matthew W. Romeyn, Trent M. Smith, Gioia D. Massa and Ye Zhang

Life 2021, 11(10), 1060; https://doi.org/10.3390/life11101060 - 9 Oct 2021

Cited by 10 | Viewed by 4300

Abstract

The establishment of steady-state continuous crop production during long-term deep space missions is critical for providing consistent nutritional and psychological benefits for the crew, potentially improving their health and performance. Three technology demonstrations were completed achieving simultaneous multi-species plant growth and the concurrent [...] Read more.

The establishment of steady-state continuous crop production during long-term deep space missions is critical for providing consistent nutritional and psychological benefits for the crew, potentially improving their health and performance. Three technology demonstrations were completed achieving simultaneous multi-species plant growth and the concurrent use of two Veggie units on the International Space Station (ISS). Microbiological characterization using molecular and culture-based methods was performed on leaves and roots from two harvests of three leafy greens, red romaine lettuce (Lactuca sativa cv. ‘Outredgeous’); mizuna mustard, (Brassica rapa var japonica); and green leaf lettuce, (Lactuca sativa cv. Waldmann’s) and associated rooting pillow components and Veggie chamber surfaces. Culture based enumeration and pathogen screening indicated the leafy greens were safe for consumption. Surface samples of the Veggie facility and plant pillows revealed low counts of bacteria and fungi and are commonly isolated on ISS. Community analysis was completed with 16S rRNA amplicon sequencing. Comparisons between pillow components, and plant tissue types from VEG-03D, E, and F revealed higher diversity in roots and rooting substrate than the leaves and wick. This work provides valuable information for food production-related research on the ISS and the impact of the plant microbiome on this unique closed environment. Full article

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24 pages, 2311 KiB

Open AccessReview

Mechano-Immunomodulation in Space: Mechanisms Involving Microgravity-Induced Changes in T Cells

by Sarit Dhar, Dilpreet Kaur Kaeley, Mohamad Jalal Kanan and Eda Yildirim-Ayan

Life 2021, 11(10), 1043; https://doi.org/10.3390/life11101043 - 3 Oct 2021

Cited by 5 | Viewed by 3504

Abstract

Of the most prevalent issues surrounding long-term spaceflight, the sustainability of human life and the maintenance of homeostasis in an extreme environment are of utmost concern. It has been observed that the human immune system is dysregulated in space as a result of [...] Read more.

Of the most prevalent issues surrounding long-term spaceflight, the sustainability of human life and the maintenance of homeostasis in an extreme environment are of utmost concern. It has been observed that the human immune system is dysregulated in space as a result of gravitational unloading at the cellular level, leading to potential complications in astronaut health. A plethora of studies demonstrate intracellular changes that occur due to microgravity; however, these ultimately fall short of identifying the underlying mechanisms and dysfunctions that cause such changes. This comprehensive review covers the changes in human adaptive immunity due to microgravity. Specifically, there is a focus on uncovering the gravisensitive steps in T cell signaling pathways. Changes in gravitational force may lead to interrupted immune signaling cascades at specific junctions, particularly membrane and surface receptor-proximal molecules. Holistically studying the interplay of signaling with morphological changes in cytoskeleton and other cell components may yield answers to what in the T cell specifically experiences the consequences of microgravity. Fully understanding the nature of this problem is essential in order to develop proper countermeasures before long-term space flight is conducted. Full article

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17 pages, 2941 KiB

Open AccessArticle

Uncovering Transcriptional Responses to Fractional Gravity in Arabidopsis Roots

by James Sheppard, Eric S. Land, Tiffany Aurora Toennisson, Colleen J. Doherty and Imara Y. Perera

Life 2021, 11(10), 1010; https://doi.org/10.3390/life11101010 - 24 Sep 2021

Cited by 9 | Viewed by 3602

Abstract

Although many reports characterize the transcriptional response of Arabidopsis seedlings to microgravity, few investigate the effect of partial or fractional gravity on gene expression. Understanding plant responses to fractional gravity is relevant for plant growth on lunar and Martian surfaces. The plant signaling [...] Read more.

Although many reports characterize the transcriptional response of Arabidopsis seedlings to microgravity, few investigate the effect of partial or fractional gravity on gene expression. Understanding plant responses to fractional gravity is relevant for plant growth on lunar and Martian surfaces. The plant signaling flight experiment utilized the European Modular Cultivation System (EMCS) onboard the International Space Station (ISS). The EMCS consisted of two rotors within a controlled chamber allowing for two experimental conditions, microgravity (stationary rotor) and simulated gravity in space. Seedlings were grown for 5 days under continuous light in seed cassettes. The arrangement of the seed cassettes within each experimental container results in a gradient of fractional g (in the spinning rotor). To investigate whether gene expression patterns are sensitive to fractional g, we carried out transcriptional profiling of root samples exposed to microgravity or partial g (ranging from 0.53 to 0.88 g). Data were analyzed using DESeq2 with fractional g as a continuous variable in the design model in order to query gene expression across the gravity continuum. We identified a subset of genes whose expression correlates with changes in fractional g. Interestingly, the most responsive genes include those encoding transcription factors, defense, and cell wall-related proteins and heat shock proteins. Full article

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14 pages, 580 KiB

Open AccessHypothesis

Effect of Microgravity Environment on Gut Microbiome and Angiogenesis

by Ruqaiyyah Siddiqui, Rizwan Qaisar, Nandu Goswami, Naveed Ahmed Khan and Adel Elmoselhi

Life 2021, 11(10), 1008; https://doi.org/10.3390/life11101008 - 24 Sep 2021

Cited by 22 | Viewed by 4389

Abstract

Microgravity environments are known to cause a plethora of stressors to astronauts. Recently, it has become apparent that gut microbiome composition of astronauts is altered following space travel, and this is of significance given the important role of the gut microbiome in human [...] Read more.

Microgravity environments are known to cause a plethora of stressors to astronauts. Recently, it has become apparent that gut microbiome composition of astronauts is altered following space travel, and this is of significance given the important role of the gut microbiome in human health. Other changes observed in astronauts comprise reduced muscle strength and bone fragility, visual impairment, endothelial dysfunction, metabolic changes, behavior changes due to fatigue or stress and effects on mental well-being. However, the effects of microgravity on angiogenesis, as well as the connection with the gut microbiome are incompletely understood. Here, the potential association of angiogenesis with visual impairment, skeletal muscle and gut microbiome is proposed and explored. Furthermore, metabolites that are effectors of angiogenesis are deliberated upon along with their connection with gut bacterial metabolites. Targeting and modulating the gut microbiome may potentially have a profound influence on astronaut health, given its impact on overall human health, which is thus warranted given the likelihood of increased human activity in the solar system, and the determination to travel to Mars in future missions. Full article

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9 pages, 1738 KiB

Open AccessArticle

Simulated Microgravity Promotes Horizontal Gene Transfer of Antimicrobial Resistance Genes between Bacterial Genera in the Absence of Antibiotic Selective Pressure

by Camilla Urbaniak, Tristan Grams, Christopher E. Mason and Kasthuri Venkateswaran

Life 2021, 11(9), 960; https://doi.org/10.3390/life11090960 - 13 Sep 2021

Cited by 12 | Viewed by 3639

Abstract

Bacteria are able to adapt and survive in harsh and changing environments through many mechanisms, with one of them being horizontal gene transfer (HGT). This process is one of the leading culprits in the spread of antimicrobial resistance (AMR) within bacterial communities and [...] Read more.

Bacteria are able to adapt and survive in harsh and changing environments through many mechanisms, with one of them being horizontal gene transfer (HGT). This process is one of the leading culprits in the spread of antimicrobial resistance (AMR) within bacterial communities and could pose a significant health threat to astronauts if they fell ill, especially on long-duration space missions. In order to better understand the degree of HGT activity that could occur in space, biosafety level-2, donor and recipient bacteria were co-cultured under simulated microgravity (SMG) on Earth with concomitant 1G controls. Two AMR genes, bla_OXA-500 and ISAba1, from the donor Acinetobacter pittii, were tracked in four recipient strains of Staphylococcus aureus (which did not harbor those genes) using polymerase chain reaction. All four S. aureus strains that were co-cultured with A. pittii under SMG had a significantly higher number of isolates that were now bla_OXA-500- and ISAba1-positive compared to growth at 1G. The acquisition of these genes by the recipient induced a phenotypic change, as these isolates were now resistant to oxacillin, which they were previously susceptible to. This is a novel study, presenting, for the first time, increased HGT activity under SMG and the potential impact of the space environment in promoting increased gene dissemination within bacterial communities. Full article

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42 pages, 6508 KiB

Open AccessReview

Biologically-Based and Physiochemical Life Support and In Situ Resource Utilization for Exploration of the Solar System—Reviewing the Current State and Defining Future Development Needs

by Ryan J. Keller, William Porter, Karthik Goli, Reece Rosenthal, Nicole Butler and Jeffrey A. Jones

Life 2021, 11(8), 844; https://doi.org/10.3390/life11080844 - 18 Aug 2021

Cited by 12 | Viewed by 11962

Abstract

The future of long-duration spaceflight missions will place our vehicles and crew outside of the comfort of low-Earth orbit. Luxuries of quick resupply and frequent crew changes will not be available. Future missions will have to be adapted to low resource environments and [...] Read more.

The future of long-duration spaceflight missions will place our vehicles and crew outside of the comfort of low-Earth orbit. Luxuries of quick resupply and frequent crew changes will not be available. Future missions will have to be adapted to low resource environments and be suited to use resources at their destinations to complete the latter parts of the mission. This includes the production of food, oxygen, and return fuel for human flight. In this chapter, we performed a review of the current literature, and offer a vision for the implementation of cyanobacteria-based bio-regenerative life support systems and in situ resource utilization during long duration expeditions, using the Moon and Mars for examples. Much work has been done to understand the nutritional benefits of cyanobacteria and their ability to survive in extreme environments like what is expected on other celestial objects. Fuel production is still in its infancy, but cyanobacterial production of methane is a promising front. In this chapter, we put forth a vision of a three-stage reactor system for regolith processing, nutritional and atmospheric production, and biofuel production as well as diving into what that system will look like during flight and a discussion on containment considerations. Full article

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33 pages, 3043 KiB

Open AccessReview

Space Radiation Protection Countermeasures in Microgravity and Planetary Exploration

by Carlos A. Montesinos, Radina Khalid, Octav Cristea, Joel S. Greenberger, Michael W. Epperly, Jennifer A. Lemon, Douglas R. Boreham, Dmitri Popov, Gitika Gorthi, Nandita Ramkumar and Jeffrey A. Jones

Life 2021, 11(8), 829; https://doi.org/10.3390/life11080829 - 14 Aug 2021

Cited by 23 | Viewed by 8205

Abstract

Background: Space radiation is one of the principal environmental factors limiting the human tolerance for space travel, and therefore a primary risk in need of mitigation strategies to enable crewed exploration of the solar system. Methods: We summarize the current state of knowledge [...] Read more.

Background: Space radiation is one of the principal environmental factors limiting the human tolerance for space travel, and therefore a primary risk in need of mitigation strategies to enable crewed exploration of the solar system. Methods: We summarize the current state of knowledge regarding potential means to reduce the biological effects of space radiation. New countermeasure strategies for exploration-class missions are proposed, based on recent advances in nutrition, pharmacologic, and immune science. Results: Radiation protection can be categorized into (1) exposure-limiting: shielding and mission duration; (2) countermeasures: radioprotectors, radiomodulators, radiomitigators, and immune-modulation, and; (3) treatment and supportive care for the effects of radiation. Vehicle and mission design can augment the overall exposure. Testing in terrestrial laboratories and earth-based exposure facilities, as well as on the International Space Station (ISS), has demonstrated that dietary and pharmacologic countermeasures can be safe and effective. Immune system modulators are less robustly tested but show promise. Therapies for radiation prodromal syndrome may include pharmacologic agents; and autologous marrow for acute radiation syndrome (ARS). Conclusions: Current radiation protection technology is not yet optimized, but nevertheless offers substantial protection to crews based on Lunar or Mars design reference missions. With additional research and human testing, the space radiation risk can be further mitigated to allow for long-duration exploration of the solar system. Full article

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20 pages, 834 KiB

Open AccessReview

Supplementing Closed Ecological Life Support Systems with In-Situ Resources on the Moon

by Alex Ellery

Life 2021, 11(8), 770; https://doi.org/10.3390/life11080770 - 30 Jul 2021

Cited by 13 | Viewed by 5355

Abstract

In this review, I explore a broad-based view of technologies for supporting human activities on the Moon and, where appropriate, Mars. Primarily, I assess the state of life support systems technology beginning with physicochemical processes, waste processing, bioregenerative methods, food production systems and [...] Read more.

In this review, I explore a broad-based view of technologies for supporting human activities on the Moon and, where appropriate, Mars. Primarily, I assess the state of life support systems technology beginning with physicochemical processes, waste processing, bioregenerative methods, food production systems and the robotics and advanced biological technologies that support the latter. We observe that the Moon possesses in-situ resources but that these resources are of limited value in closed ecological life support systems (CELSS)—indeed, CELSS technology is most mature in recycling water and oxygen, the two resources that are abundant on the Moon. This places a premium on developing CELSS that recycle other elements that are rarified on the Moon including C and N in particular but also other elements such as P, S and K which might be challenging to extract from local resources. Although we focus on closed loop ecological life support systems, we also consider related technologies that involve the application of biological organisms to bioregenerative medical technologies and bioregenerative approaches to industrial activity on the Moon as potential future developments. Full article

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11 pages, 815 KiB

Open AccessArticle

Effects of Resistance Exercise with or without Whey Protein Supplementation on Ocular Changes after a 21-Day Head-Down Bed Rest

by Marc Kermorgant, Sirine Hammoud, Laurence Mahieu, Thomas Geeraerts, Arnaud Beck, Marie-Pierre Bareille, Vincent Soler, Anne Pavy-Le Traon and Jean-Claude Quintyn

Life 2021, 11(8), 741; https://doi.org/10.3390/life11080741 - 26 Jul 2021

Cited by 1 | Viewed by 2222

Abstract

Neuro-ophthalmological changes have been reported after prolonged exposure to microgravity; however, the pathophysiology remains unclear. The objectives of the present study were twofold: (1) to assess the neuro-ophthalmological impact of 21 days of head-down bed rest (HDBR) and (2) to determine the effects [...] Read more.

Neuro-ophthalmological changes have been reported after prolonged exposure to microgravity; however, the pathophysiology remains unclear. The objectives of the present study were twofold: (1) to assess the neuro-ophthalmological impact of 21 days of head-down bed rest (HDBR) and (2) to determine the effects of resistance vibration exercise (RVE) alone or combined with nutritional supplementation (NeX). In this case, 12 healthy male subjects completed three interventions of a 21-day HDBR: a control condition without countermeasure (CON), a condition with resistance vibration exercise (RVE) comprising of squats, single leg heel and bilateral heel raises and a condition using also RVE associated with nutritional supplementation (NeX). Intraocular pressure (IOP) was assessed by applanation tonometry. Retinal nerve fiber layer thickness (RNFLT) was assessed with spectral-domain optical coherence tomography, before HDBR and between Day 2 and Day 4 after each session of HDBR. In CON condition, IOP was preserved; while in RVE and NeX conditions, IOP was increased. In CON condition, RNFLT was preserved after HDBR. RVE and NeX conditions did not have significant effects on RNFLT. This study showed that a 3-week HDBR did not induce significant ophthalmological changes. However, RVE induced an elevation in IOP after HDBR. Nutritional supplementation did not reduce or exacerbate the side effects of RVE. Full article

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13 pages, 2116 KiB

Open AccessArticle

A Microbial Monitoring System Demonstrated on the International Space Station Provides a Successful Platform for Detection of Targeted Microorganisms

by Christina L. M. Khodadad, Cherie M. Oubre, Victoria A. Castro, Stephanie M. Flint, Monsi C. Roman, Charlie Mark Ott, Cory J. Spern, Mary E. Hummerick, Gretchen J. Maldonado Vazquez, Michele N. Birmele, Quinn Whitlock, Matt Scullion, Christina M. Flowers, Raymond M. Wheeler and Orlando Melendez

Life 2021, 11(6), 492; https://doi.org/10.3390/life11060492 - 27 May 2021

Cited by 8 | Viewed by 3904

Abstract

Closed environments such as the International Space Station (ISS) and spacecraft for other planned interplanetary destinations require sustainable environmental control systems for manned spaceflight and habitation. These systems require monitoring for microbial contaminants and potential pathogens that could foul equipment or affect the [...] Read more.

Closed environments such as the International Space Station (ISS) and spacecraft for other planned interplanetary destinations require sustainable environmental control systems for manned spaceflight and habitation. These systems require monitoring for microbial contaminants and potential pathogens that could foul equipment or affect the health of the crew. Technological advances may help to facilitate this environmental monitoring, but many of the current advances do not function as expected in reduced gravity conditions. The microbial monitoring system (RAZOR^® EX) is a compact, semi-quantitative rugged PCR instrument that was successfully tested on the ISS using station potable water. After a series of technical demonstrations between ISS and ground laboratories, it was determined that the instruments functioned comparably and provided a sample to answer flow in approximately 1 hour without enrichment or sample manipulation. Post-flight, additional advancements were accomplished at Kennedy Space Center, Merritt Island, FL, USA, to expand the instrument’s detections of targeted microorganisms of concern such as water, food-borne, and surface microbes including Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Escherichia coli, and Aeromonas hydrophilia. Early detection of contaminants and bio-fouling microbes will increase crew safety and the ability to make appropriate operational decisions to minimize exposure to these contaminants. Full article

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8 pages, 772 KiB

Open AccessArticle

Plantar Stimulations during 3-Day Hindlimb Unloading Prevent Loss of Neural Progenitors and Maintain ERK1/2 Activity in the Rat Hippocampus

by Anna S. Berezovskaya, Sergey A. Tyganov, Svetlana D. Nikolaeva, Alexandra A. Naumova, Boris S. Shenkman and Margarita V. Glazova

Life 2021, 11(5), 449; https://doi.org/10.3390/life11050449 - 17 May 2021

Cited by 6 | Viewed by 2266

Abstract

Adult neurogenesis is a flexible process that depends on the environment and correlates with cognitive functions. Cognitive functions are impaired by various factors including space flight conditions and reduced physical activity. Physically active life significantly improves both cognition and the hippocampal neurogenesis. Here, [...] Read more.

Adult neurogenesis is a flexible process that depends on the environment and correlates with cognitive functions. Cognitive functions are impaired by various factors including space flight conditions and reduced physical activity. Physically active life significantly improves both cognition and the hippocampal neurogenesis. Here, we analyzed how 3-day simulated microgravity caused by hindlimb unloading (HU) or dynamic foot stimulation (DFS) during HU can affect the hippocampal neurogenesis. Adult Wistar rats were recruited in the experiments. The results demonstrated a decrease in the number of doublecortine (DCX) positive neural progenitors, but proliferation in the subgranular zone of the dentate gyrus was not changed after 3-day HU. Analysis of the effects of DFS showed restoration of neural progenitor population in the subgranular zone of the dentate gyrus. Additionally, we analyzed activity of the cRaf/ERK1/2 pathway, which is one of the major players in the regulation of neuronal differentiation. The results demonstrated inhibition of cRaf/ERK1/2 signaling in the hippocampus of HU rats. In DFS rats, no changes in the activity of cRaf/ERK1/2 were observed. Thus, we demonstrated that the process of neurogenesis fading during HU begins with inhibition of the formation of immature neurons and associated ERK1/2 signaling activity, while DFS prevents the development of mentioned alterations. Full article

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24 pages, 2410 KiB

Open AccessFeature PaperArticle

Growth and Antifungal Resistance of the Pathogenic Yeast, Candida Albicans, in the Microgravity Environment of the International Space Station: An Aggregate of Multiple Flight Experiences

by Sheila Nielsen, Kenna White, Kyle Preiss, Dakota Peart, Kathryn Gianoulias, Rachel Juel, James Sutton, James McKinney, Jaclyn Bender, Gabrielle Pinc, Kela Bergren, Wendy Gans, Jessica Kelley and Millard McQuaid

Life 2021, 11(4), 283; https://doi.org/10.3390/life11040283 - 27 Mar 2021

Cited by 8 | Viewed by 4267

Abstract

This report was designed to compare spaceflight-induced cellular and physiological adaptations of Candida albicans cultured in microgravity on the International Space Station across several payloads. C. albicans is a common opportunistic fungal pathogen responsible for a variety of superficial infections as well as [...] Read more.

This report was designed to compare spaceflight-induced cellular and physiological adaptations of Candida albicans cultured in microgravity on the International Space Station across several payloads. C. albicans is a common opportunistic fungal pathogen responsible for a variety of superficial infections as well as systemic and more severe infections in humans. Cumulatively, the propensity of this organism to be widespread through the population, the ability to produce disease in immunocompromised individuals, and the tendency to respond to environmental stress with characteristics associated with increased virulence, require a better understanding of the yeast response to microgravity for spaceflight crew safety. As such, the responses of this yeast cultivated during several missions using two in-flight culture bioreactors were analyzed and compared herein. In general, C. albicans had a slightly shorter generation time and higher growth propensity in microgravity as compared to terrestrial controls. Rates of cell filamentation differed between bioreactors, but were low and not significantly different between flight and terrestrial controls. Viable cells were retrieved and cultured, resulting in a colony morphology that was similar between cells cultivated in flight and in terrestrial control conditions, and in contrast to that previously observed in a ground-based microgravity analog system. Of importance, yeast demonstrated an increased resistance when challenged during spaceflight with the antifungal agent, amphotericin B. Similar levels of resistance were not observed when challenged with the functionally disparate antifungal drug caspofungin. In aggregate, yeast cells cultivated in microgravity demonstrated a subset of characteristics associated with virulence. In addition, and beyond the value of the specific responses of C. albicans to microgravity, this report includes an analysis of biological reproducibility across flight opportunities, compares two spaceflight hardware systems, and includes a summary of general flight and payload timelines. Full article

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17 pages, 1256 KiB

Open AccessReview

Immunity in Space: Prokaryote Adaptations and Immune Response in Microgravity

by Macauley J. Green, Jonathan W. Aylott, Paul Williams, Amir M. Ghaemmaghami and Philip M. Williams

Life 2021, 11(2), 112; https://doi.org/10.3390/life11020112 - 2 Feb 2021

Cited by 17 | Viewed by 5424

Abstract

Immune dysfunction has long been reported by medical professionals regarding astronauts suffering from opportunistic infections both during their time in space and a short period afterwards once back on Earth. Various species of prokaryotes onboard these space missions or cultured in a microgravity [...] Read more.

Immune dysfunction has long been reported by medical professionals regarding astronauts suffering from opportunistic infections both during their time in space and a short period afterwards once back on Earth. Various species of prokaryotes onboard these space missions or cultured in a microgravity analogue exhibit increased virulence, enhanced formation of biofilms, and in some cases develop specific resistance for specific antibiotics. This poses a substantial health hazard to the astronauts confined in constant proximity to any present bacterial pathogens on long space missions with a finite number of resources including antibiotics. Furthermore, some bacteria cultured in microgravity develop phenotypes not seen in Earth gravity conditions, providing novel insights into bacterial evolution and avenues for research. Immune dysfunction caused by exposure to microgravity may increase the chance of bacterial infection. Immune cell stimulation, toll-like receptors and pathogen-associated molecular patterns can all be altered in microgravity and affect immunological crosstalk and response. Production of interleukins and other cytokines can also be altered leading to immune dysfunction when responding to bacterial infection. Stem cell differentiation and immune cell activation and proliferation can also be impaired and altered by the microgravity environment once more adding to immune dysfunction in microgravity. This review elaborates on and contextualises these findings relating to how bacteria can adapt to microgravity and how the immune system subsequently responds to infection. Full article

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26 pages, 2937 KiB

Open AccessReview

Reproduction and the Early Development of Vertebrates in Space: Problems, Results, Opportunities

by Alexandra Proshchina, Victoria Gulimova, Anastasia Kharlamova, Yuliya Krivova, Nadezhda Besova, Rustam Berdiev and Sergey Saveliev

Life 2021, 11(2), 109; https://doi.org/10.3390/life11020109 - 31 Jan 2021

Cited by 10 | Viewed by 7803

Abstract

Humans and animals adapt to space flight conditions. However, the adaptive changes of fully formed organisms differ radically from the responses of vertebrate embryos, foetuses, and larvae to space flight. Development is associated with active cell proliferation and the formation of organs and [...] Read more.

Humans and animals adapt to space flight conditions. However, the adaptive changes of fully formed organisms differ radically from the responses of vertebrate embryos, foetuses, and larvae to space flight. Development is associated with active cell proliferation and the formation of organs and systems. The instability of these processes is well known. Over 20 years has passed since the last systematic experiments on vertebrate reproduction and development in space flight. At the same time, programs are being prepared for the exploration of Mars and the Moon, which justifies further investigations into space flight’s impact on vertebrate development. This review focuses on various aspects of reproduction and early development of vertebrates in space flights. The results of various experiments on fishes, amphibians, reptiles, birds and mammals are described. The experiments in which our team took part and ontogeny of the vertebrate nervous and special sensory systems are considered in more detail. Possible causes of morphological changes are also discussed. Research on evolutionarily and taxonomically different models can advance the understanding of reproduction in microgravity. Reptiles, in particular, geckos, due to their special features, can be a promising object of space developmental biology. Full article

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14 pages, 2915 KiB

Open AccessArticle

Knowledge Network Embedding of Transcriptomic Data from Spaceflown Mice Uncovers Signs and Symptoms Associated with Terrestrial Diseases

by Charlotte A. Nelson, Ana Uriarte Acuna, Amber M. Paul, Ryan T. Scott, Atul J. Butte, Egle Cekanaviciute, Sergio E. Baranzini and Sylvain V. Costes

Life 2021, 11(1), 42; https://doi.org/10.3390/life11010042 - 12 Jan 2021

Cited by 15 | Viewed by 6708

Abstract

There has long been an interest in understanding how the hazards from spaceflight may trigger or exacerbate human diseases. With the goal of advancing our knowledge on physiological changes during space travel, NASA GeneLab provides an open-source repository of multi-omics data from real [...] Read more.

There has long been an interest in understanding how the hazards from spaceflight may trigger or exacerbate human diseases. With the goal of advancing our knowledge on physiological changes during space travel, NASA GeneLab provides an open-source repository of multi-omics data from real and simulated spaceflight studies. Alone, this data enables identification of biological changes during spaceflight, but cannot infer how that may impact an astronaut at the phenotypic level. To bridge this gap, Scalable Precision Medicine Oriented Knowledge Engine (SPOKE), a heterogeneous knowledge graph connecting biological and clinical data from over 30 databases, was used in combination with GeneLab transcriptomic data from six studies. This integration identified critical symptoms and physiological changes incurred during spaceflight. Full article

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11 pages, 653 KiB

Open AccessHypothesis

Mechanotransduction in Prokaryotes: A Possible Mechanism of Spaceflight Adaptation

by Patricia Fajardo-Cavazos and Wayne L. Nicholson

Life 2021, 11(1), 33; https://doi.org/10.3390/life11010033 - 7 Jan 2021

Cited by 17 | Viewed by 3725

Abstract

Our understanding of the mechanisms of microgravity perception and response in prokaryotes (Bacteria and Archaea) lag behind those which have been elucidated in eukaryotic organisms. In this hypothesis paper, we: (i) review how eukaryotic cells sense and respond to microgravity using various pathways [...] Read more.

Our understanding of the mechanisms of microgravity perception and response in prokaryotes (Bacteria and Archaea) lag behind those which have been elucidated in eukaryotic organisms. In this hypothesis paper, we: (i) review how eukaryotic cells sense and respond to microgravity using various pathways responsive to unloading of mechanical stress; (ii) we observe that prokaryotic cells possess many structures analogous to mechanosensitive structures in eukaryotes; (iii) we review current evidence indicating that prokaryotes also possess active mechanosensing and mechanotransduction mechanisms; and (iv) we propose a complete mechanotransduction model including mechanisms by which mechanical signals may be transduced to the gene expression apparatus through alterations in bacterial nucleoid architecture, DNA supercoiling, and epigenetic pathways. Full article

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2020

Jump to: 2024, 2022, 2021

22 pages, 1513 KiB

Open AccessReview

Approaching Gravity as a Continuum Using the Rat Partial Weight-Bearing Model

by Marie Mortreux and Megan E. Rosa-Caldwell

Life 2020, 10(10), 235; https://doi.org/10.3390/life10100235 - 8 Oct 2020

Cited by 11 | Viewed by 4946

Abstract

For decades, scientists have relied on animals to understand the risks and consequences of space travel. Animals remain key to study the physiological alterations during spaceflight and provide crucial information about microgravity-induced changes. While spaceflights may appear common, they remain costly and, coupled [...] Read more.

For decades, scientists have relied on animals to understand the risks and consequences of space travel. Animals remain key to study the physiological alterations during spaceflight and provide crucial information about microgravity-induced changes. While spaceflights may appear common, they remain costly and, coupled with limited cargo areas, do not allow for large sample sizes onboard. In 1979, a model of hindlimb unloading (HU) was successfully created to mimic microgravity and has been used extensively since its creation. Four decades later, the first model of mouse partial weight-bearing (PWB) was developed, aiming at mimicking partial gravity environments. Return to the Lunar surface for astronauts is now imminent and prompted the need for an animal model closer to human physiology; hence in 2018, our laboratory created a new model of PWB for adult rats. In this review, we will focus on the rat model of PWB, from its conception to the current state of knowledge. Additionally, we will address how this new model, used in conjunction with HU, will help implement new paradigms allowing scientists to anticipate the physiological alterations and needs of astronauts. Finally, we will discuss the outstanding questions and future perspectives in space research and propose potential solutions using the rat PWB model. Full article

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12 pages, 2181 KiB

Open AccessArticle

Integrated RNA-seq Analysis Indicates Asynchrony in Clock Genes between Tissues under Spaceflight

by Shin-ichiro Fujita, Lindsay Rutter, Quang Ong and Masafumi Muratani

Life 2020, 10(9), 196; https://doi.org/10.3390/life10090196 - 11 Sep 2020

Cited by 16 | Viewed by 6366

Abstract

Rodent models have been widely used as analogs for estimating spaceflight-relevant molecular mechanisms in human tissues. NASA GeneLab provides access to numerous spaceflight omics datasets that can potentially generate novel insights and hypotheses about fundamental space biology when analyzed in new and integrated [...] Read more.

Rodent models have been widely used as analogs for estimating spaceflight-relevant molecular mechanisms in human tissues. NASA GeneLab provides access to numerous spaceflight omics datasets that can potentially generate novel insights and hypotheses about fundamental space biology when analyzed in new and integrated fashions. Here, we performed a pilot study to elucidate space biological mechanisms across tissues by reanalyzing mouse RNA-sequencing spaceflight data archived on NASA GeneLab. Our results showed that clock gene expressions in spaceflight mice were altered compared with those in ground control mice. Furthermore, the results suggested that spaceflight promotes asynchrony of clock gene expressions between peripheral tissues. Abnormal circadian rhythms are associated not only with jet lag and sleep disorders but also with cancer, lifestyle-related diseases, and mental disorders. Overall, our findings highlight the importance of elucidating the causes of circadian rhythm disruptions using the unique approach of space biology research to one day potentially develop countermeasures that benefit humans on Earth and in space. Full article

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