Researchers at the University of Central Florida report that the liver responds to space radiation and microgravity with molecular changes that look strikingly like accelerated aging. Michal Masternak, a professor of medicine who leads the UCF College of Medicine's aging and space medicine research, said his team saw many genetic changes in the liver just 24 hours after radiation exposure, and that those changes closely resembled what happens during normal aging.
To get there, UCF scientists worked with other U.S. researchers to build a simulated deep space environment in the laboratory. Animal models spent 14 days in simulated microgravity and were exposed at the NASA Space Radiation Laboratory to galactic cosmic radiation and solar particle events calibrated to approximate the dose an astronaut would absorb on a trip to Mars.
The liver was the target for a practical reason: it is one of the body's central metabolic organs, and disruptions to metabolism ripple outward into many age-related conditions. Masternak's group suggests that if a short exposure produces this much genetic disturbance, longer missions could cause substantially more damage - a real consideration as space agencies plan multi-year flights.
The more immediate relevance for people who will never leave Earth is that the affected genes and pathways amount to a list of possible drug targets. If radiation can push liver tissue into an aging-like state on a compressed timeline, studying that process may help identify what could be blocked or reversed in ordinary aging. This work was done in animal models under simulated conditions, so the next step is establishing how well these findings translate to human biology and to longer exposures.