A new investigation heading to the International Space Station will provide space-flown samples to scientists from academia, industry and government agencies, who have agreed to share their data and results in an online database that is open to the public. Rodent Research-8 (RR-8) examines the physiology of aging and the effect of age on disease progression using groups of young and old mice flown in space and kept on Earth.
“The objective is to expose the mice to microgravity and track physiological changes,” said Michael S. Roberts, deputy chief scientist at the U.S. National Laboratory, a sponsor of the investigation. “Tissue samples from space-flown animals are extremely valuable to biomedical research and opportunities to use the space station are limited to a few missions each year. This investigation was conceived primarily to provide the biomedical research community on Earth with tissues from mice exposed to microgravity.” Scientists receiving tissue samples include investigators at Stanford University, University of Southern California, University of Kansas, Virginia Commonwealth University, Northwestern University, Biogen, KBRwyle, LaunchPad Medical LLC, the U.S. Air Force and the NASA Gene Lab program, a science collaboration initiative at NASA Ames Research Center.
Previous research has shown that spending time in space causes bone density loss, immune dysfunction, cardiovascular issues such as stiffening of arteries, and loss of skeletal muscle mass and strength in both humans and rodent models. These changes resemble aging in people age on Earth, but happen more quickly. That makes spaceflight an opportunity to study – and perhaps lessen – the effects of aging.
“There is something about being in space for an extended period of time, more than several weeks,” said Roberts. “A lot of the experiments with rodents on the space station have looked at the effects of microgravity, but microgravity may not be the sole cause. Exposure to the space environment also involves radiation, stress, and other factors that affect health. It could be some combination of all of them. Part of this experiment is validating that general aging response in the mice.”
The investigation keeps a group of young mice (10-16 weeks old) and another group of older mice (30-52 weeks old) on the space station for different periods of time – approximately 30 and 60 days – to make it possible to examine that accelerated aging process more closely. Researchers also plan to observe the activity levels of the different groups, expecting the younger mice to be more active than the older ones. Activity, or exercise, is known to affect the rate of bone and muscle loss in mice just as it does in humans. The mice, provided by Taconic Biosciences, are all from a genetically identical strain.
“We are trying to get down to the molecular basis for what is happening,” Roberts said. “To use mice or other organisms as models for studying humans, we need to understand whether the effects of space exposure have the same causes and outcomes as conditions in humans on Earth. We want to see if the same things happen in mice and whether the rate of change is affected by the age of the mouse at exposure.”
Better understanding of changes to the body that occur in spaceflight can contribute to developing countermeasures and therapies that protect the health of astronauts and help people with age-related conditions and diseases on Earth.
While this investigation focuses on the effect of age on the changes induced by space, future investigations could compare males versus females or different genetic strains of mice, or the effects of varying their habitat on the space station.
RR8 makes use of the Life Sciences Glovebox (LSG), a sealed workbench-type environment for life science and technology investigations on the space station. Its larger size allows two crew members to work in the LSG simultaneously.