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

Area of Science:

• Space exploration
• Radiation biology
• Biomedical engineering

Background:

• Long-term space travel presents significant health risks, including exposure to ionizing radiation.
• Ionizing radiation can cause cellular damage, genomic instability, and gastrointestinal issues, posing a major obstacle for missions to Mars.
• Current radiation shielding methods have limitations and can produce harmful secondary particles.

Purpose of the Study:

• To investigate the potential radioprotective effects of an induced torpor-like state against space radiation exposure.
• To test the hypothesis that a hibernation-like state can mitigate radiation-induced damage in the gastrointestinal tract.

Main Methods:

• A torpor-like state was induced in zebrafish using melatonin and reduced temperature.
• Zebrafish were exposed to low-dose radiation twice over 10 days.
• RNA sequencing and qPCR analyzed gene expression in the gastrointestinal tract to assess protective effects.

Main Results:

• Melatonin and cold successfully induced a torpor-like state, characterized by reduced metabolism and activity.
• Radiation exposure triggered DNA damage, oxidative stress, and cellular stress responses.
• The induced torpor state attenuated radiation's harmful effects by increasing pro-survival signals and reducing oxidative stress.

Conclusions:

• An induced torpor-like state demonstrates significant radioprotective potential.
• This hibernation-like state may serve as a novel countermeasure for mitigating radiation damage during long-duration space travel.
• Further research is warranted to explore this approach for human space exploration.