PUBLICATION

Induced Torpor as a Countermeasure for Low Dose Radiation Exposure in a Zebrafish Model

Authors
Cahill, T., da Silveira, W.A., Renaud, L., Williamson, T., Wang, H., Chung, D., Overton, I., Chan, S.S.L., Hardiman, G.
ID
ZDB-PUB-210501-14
Date
2021
Source
Cells   10(4): (Journal)
Registered Authors
Chan, Sherine
Keywords
bioinformatics, countermeasure, metabolism, radiation, signalling pathways, space, temperature, torpor, transcriptome, zebrafish
Datasets
GEO:GSE169522
MeSH Terms
  • Animals
  • Circadian Rhythm/genetics
  • Circadian Rhythm/radiation effects
  • Dose-Response Relationship, Radiation
  • Endoplasmic Reticulum-Associated Degradation/radiation effects
  • Gene Expression Regulation/radiation effects
  • Gene Regulatory Networks/radiation effects
  • Melatonin/pharmacology
  • Models, Animal
  • Oxidative Phosphorylation/radiation effects
  • Radiation Exposure*
  • Reproducibility of Results
  • Stress, Physiological/genetics
  • Stress, Physiological/radiation effects
  • Survival Analysis
  • Temperature
  • Torpor/physiology*
  • Transcriptome/genetics
  • Transcriptome/radiation effects
  • Zebrafish/genetics
  • Zebrafish/physiology*
PubMed
33920039 Full text @ Cells
Abstract
The development of the Artemis programme with the goal of returning to the moon is spurring technology advances that will eventually take humans to Mars and herald a new era of interplanetary space travel. However, long-term space travel poses unique challenges including exposure to ionising radiation from galactic cosmic rays and potential solar particle events, exposure to microgravity and specific nutritional challenges arising from earth independent exploration. Ionising radiation is one of the major obstacles facing future space travel as it can generate oxidative stress and directly damage cellular structures such as DNA, in turn causing genomic instability, telomere shortening, extracellular-matrix remodelling and persistent inflammation. In the gastrointestinal tract (GIT) this can lead to leaky gut syndrome, perforations and motility issues, which impact GIT functionality and affect nutritional status. While current countermeasures such as shielding from the spacecraft can attenuate harmful biological effects, they produce harmful secondary particles that contribute to radiation exposure. We hypothesised that induction of a torpor-like state would confer a radioprotective effect given the evidence that hibernation extends survival times in irradiated squirrels compared to active controls. To test this hypothesis, a torpor-like state was induced in zebrafish using melatonin treatment and reduced temperature, and radiation exposure was administered twice over the course of 10 days. The protective effects of induced-torpor were assessed via RNA sequencing and qPCR of mRNA extracted from the GIT. Pathway and network analysis were performed on the transcriptomic data to characterise the genomic signatures in radiation, torpor and torpor + radiation groups. Phenotypic analyses revealed that melatonin and reduced temperature successfully induced a torpor-like state in zebrafish as shown by decreased metabolism and activity levels. Genomic analyses indicated that low dose radiation caused DNA damage and oxidative stress triggering a stress response, including steroidal signalling and changes to metabolism, and cell cycle arrest. Torpor attenuated the stress response through an increase in pro-survival signals, reduced oxidative stress via the oxygen effect and detection and removal of misfolded proteins. This proof-of-concept model provides compelling initial evidence for utilizing an induced torpor-like state as a potential countermeasure for radiation exposure.
Genes / Markers
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Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping