Spaceflight might age some human stem cells quicker, but the damage may not be permanent. A recent study published in Cell Stem Cell highlights how time on the International Space Station (ISS) affects hematopoietic stem and progenitor cells (HSPCs), which are crucial for our blood and immune health.
Researchers found that exposure to space conditions led to changes in these cells. They became less effective at creating new cells and showed signs of accelerated aging. This includes signs of DNA damage and shortened telomeres, which are protective ends of chromosomes.
The main culprits? Radiation and microgravity. These stressors were evident in HSPCs sent into space on SpaceX missions. Catriona Jamieson, a study co-author and director at the Sanford Stem Cell Institute, explained that understanding these changes is vital. It will help protect astronauts during long missions and provide insights into aging and diseases like cancer on Earth.
This research builds on prior studies involving identical NASA twin astronauts, Scott and Mark Kelly. Scott spent nearly a year in space while Mark stayed on Earth, providing unique insights into how spaceflight impacts the human body. Remarkably, 91.3% of Scott’s gene expression returned to normal within six months of returning home.
Interestingly, Scott’s telomeres showed significant changes during his flight. NASA reported that while some telomeres lengthened, most returned to normal shortly after he landed. This raises important questions about how space affects cellular aging.
The recent study also used an ISS platform that allowed researchers to cultivate HSPCs in space while using AI tools to monitor them. These cells were exposed to space for 32 to 45 days, shorter than typical six-month missions. Upon returning to Earth, some cells showed signs of recovery when placed in a healthy environment, suggesting that the damage from spaceflight could be reversible.
Despite their time in space, researchers noted that these cells displayed more stress and inflammation. This led to less ability to regenerate and increased DNA damage.
With 17 missions to the ISS under its belt, UC San Diego plans even more studies to explore HSPCs. They aim to conduct real-time monitoring of molecular changes and investigate ways to counteract the effects of space travel on human health.
This research could reshape our understanding of human development in extreme environments. As we venture further into space, insights like these will be essential to keep astronauts healthy during long missions.
For more detailed information, check out the study published on September 4 in Cell Stem Cell here.
