Search PubMedSearch

SEARCH · Search PubMed

Results for “Astronauts”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

4 recordsLinked to original sources

Using Organoids to Unlock the Potential of Human Torpor for Spaceflight.

PURPOSE OF REVIEW: This paper reviews the current understanding of the potential for humans to enter a state of torpor/hibernation, and discusses the possibility of inducing torpor in astronauts for long-duration space travel, including some of the physiological, technological, and ethical considerations associated with its implementation. By exploring means to induce torpor in various human organoid systems, we hope such research can provides insights to comprehensive solutions to overcome some of the major hurdles that limit the potential for human to enter a state of torpor during long-duration deep-space missions, and contribute to the ongoing efforts to make such missions more feasible and safer for astronauts. RECENT FINDINGS: On future deep space missions such as NASA's planned missions to the Moon, Mars, and near-Earth asteroids, astronauts will be continuously exposed to environments that are radically different from those on Earth, each presenting multiple logistical and physiological challenges. Beyond the well-documented physiological effects of microgravity, space travelers will encounter a complex radiation environment that may contribute to significant short- and long-term adverse effects on human physiology and increase the risk of cancer and other diseases. Besides these physical challenges, life support systems must also be designed to mitigate psychological impacts of long-term isolation and confinement - all of which collectively pose formidable engineering problems. Hibernation/torpor is a state of prolonged inactivity and metabolic depression used by a wide variety of mammals to survive periods of cold temperatures and food scarcity, including some primates and perhaps even an extinct early line of hominins that lived nearly half a million years ago. Since modern humans share common ancestry with these hominins and hibernating primates, it is likely the human genome encodes the necessary genetic information to hibernate, or at least enter the similar, more transient state of torpor. The reduced body activity, lowered metabolism, and decreased energy requirements that characterize torpor suggest that developing means of inducing such a state in astronauts could address these challenges, including providing a degree of radioprotection. SUMMARY: This review explores the potential application of human torpor as a countermeasure to address the many challenges posed by long-duration spaceflight beyond low-Earth orbit (LEO), discusses various natural hibernating model systems for studying means of inducing a torpor-like state in humans, and highlights the vast potential of using human organoids to test and validate mechanisms that govern induction and maintenance of torpor to identify the means to one day safely induce this state in astronauts to provide additional protection from the myriad stressors of spaceflight.

Astronaut Health

Selective saccular plasticity under microgravity links peripheral transcriptomic remodeling to postflight vestibular dysfunction.

Long-duration exposure to microgravity disrupts human balance and spatial orientation, yet the molecular mechanisms underlying vestibular adaptation to spaceflight remain poorly understood. Here, we tested the hypothesis that the saccule, the primary gravity-sensing otolith organ, undergoes selective remodeling during spaceflight and contributes to transient postflight postural instability. Using a cross-species approach, we combined transcriptomic analysis of mouse otolith organs with physiological assessments in astronauts. Laser microdissection-based RNA sequencing of mouse otolith sensory epithelia after a 35-d spaceflight revealed pronounced, organ-specific transcriptomic remodeling in the saccule, whereas the utricle remained stable. Principal component and clustering analyses demonstrated that the saccular transcriptome shifted toward an utricle-like profile under microgravity, accompanied by changes in genes related to synaptic and neuronal function. Promoter motif analysis identified NFAT-associated transcriptional networks, suggesting Ca2+-dependent regulation of synaptic plasticity as a potential molecular substrate of gravity-dependent adaptation. In parallel, vestibular testing in astronauts following long-duration missions (157 to 328 d) revealed selective attenuation of saccule-mediated cervical vestibular-evoked myogenic potentials and increased postural sway immediately after return to Earth, while utricle-mediated responses and semicircular canal function were preserved. Both saccular function and postural stability recovered within approximately 10 d. Notably, early postflight postural instability was partially mitigated by noisy galvanic vestibular stimulation, consistent with stochastic resonance-mediated sensory enhancement. Together, these findings identify the saccule as a plastic gravity sensor and establish a mechanistic link between peripheral molecular remodeling and functional balance deficits after spaceflight, providing a framework for developing countermeasures to facilitate vestibular readaptation during human space exploration.

Animals

Methodologies for Mitochondrial Omic Profiling During Spaceflight.

To be able to understand how spaceflight can affect human biology, there is a need for maximizing the amount of information that can be obtained from experiments flown to space. Recently there has been an influx of data obtained from astronauts through multi-omics approaches based on both governmental and commercial spaceflight missions. In addition to data from humans, mitochondrial specific data is gathered for other experiments from rodents and other organisms that are flown in space. This data has started to universally demonstrate that mitochondrial dysfunction is the key regulator associated with increasing health risks associated with spaceflight. This mitochondrial dysfunction can have influence downstream on immune suppression, inflammation, circadian rhythm issues, and more. Due to the space environment, standard methodologies have to be altered for performing mitochondrial specific analysis and in general sample collection for omics. To perform mitochondrial specific analysis and data collection from samples flown to space we will outline the current sample collection methods, processing of the samples, and specific analysis. Specifically we will highlight the different mitochondrial methodologies and challenges involved with research associated with spaceflight.

Space Flight

Leveraging bioinformatics approaches for drug repositioning in space radiation protection.

The health effects of space radiation, primarily Galactic Cosmic Rays (GCRs), on humans remain largely unknown, with potential cardiovascular consequences posing a significant threat to astronauts on long-duration spaceflight missions. Currently, there are no established pharmacological countermeasures for GCR exposure. Drug repositioning offers a promising strategy to accelerate pharmaceutical research in space medicine. This study leverages existing bioinformatics techniques to identify and prioritize potential drug candidates associated with proteomic perturbations following simulated GCR exposure using previously published murine cardiac proteomic data. A protein-protein interaction (PPI) network was constructed using the top differentially expressed proteins (DEPs) from murine heart tissue following exposure to 5-ion GCRs as seed nodes, focusing on experimentally supported interactions. Network topology, Markov clustering, and functional enrichment analyses were used to characterize biologically relevant proteins and pathways. Drug-protein interactions were predicted using Drugst.One and mapped to PPI clusters of interest to identify candidate drugs. Selected drug-macromolecule interactions were further explored using CB-Dock2 molecular docking and short-duration molecular dynamics simulations as hypothesis-generating structural assessments. Analysis of a key PPI network cluster consisting of several ATP synthase proteins identified 23 unique drug candidates. These analyses demonstrate a systematic approach for leveraging bioinformatics techniques to identify candidate molecular targets and generate pharmacological hypotheses in the context of space radiation countermeasures. Ultimately, this strategy introduces a hypothesis-generating framework for the prioritization of potential drug candidates for future computational characterization and experimental investigation against spaceflight stressors.

Animals