American scientists sent brain tissue organoids, representing human brain cells, to the International Space Station (ISS), and the results have surprised everyone.
In the 2019 experiment, these mini-brain structures, which spent a month in low Earth orbit, not only survived but also matured faster than their Earth-grown counterparts.
Molecular biologist Jeanne Loring from the Scripps Research Institute said, "It was a big surprise that these cells survived in space. This study opens the door for new experiments to explore other brain regions affected by neurodegenerative diseases."
Organoids are defined as three-dimensional cell clusters derived from tissue or stem cells that can self-renew and exhibit organ-like functions. They structurally and functionally resemble the tissue from which they were obtained.
SPACE AND HEALTH RESEARCH INTERSECTION
The ISS offers a unique opportunity to study the effects of microgravity on human cells. These effects are crucial not only for astronaut health but also for medical research on Earth. Microgravity is opening new doors for disease modeling and drug development.
Led by molecular biologist Davide Marotta from the ISS National Lab, a team set out to investigate how nerve cells, particularly those associated with neurodegenerative diseases, are affected by microgravity.
In the study, cells from healthy individuals and those with multiple sclerosis (MS) and Parkinson's disease were reprogrammed in the lab to become nerve cells. These cells formed organoids containing microglia, the brain's immune cells. Some organoids remained on Earth, while others were sent to the ISS in special cryotubes.
After spending a month in space, the organoids were compared with the Earth-based control group.
FASTER MATURATION, LOWER STRESS LEVELS
The organoids that developed in space matured more quickly, but cell proliferation was slower. Also, compared to their Earth counterparts, stress-related genes were less expressed, and inflammation was lower than expected.
This could be due to microgravity conditions being closer to the natural conditions inside the human skull. Loring added, "In space, these organoids resemble the brain more. They're creating their own micro-universe."
NEW HORIZONS FOR FUTURE RESEARCH
Researchers noted that the next goal is to examine the brain regions most affected by Alzheimer's disease. New experiments are also planned to understand how nerve cells in space connect with each other.
Loring explained, "In this type of study, we can't predict results based on previous research. We're truly at the starting point; we're in the sky, but we're still at the fundamental stage."
The results of the research were published in Stem Cells Translational Medicine.
