Human stem cells age more rapidly in space, study finds

While scientists are still working to understand the effects an extended trip to space can have on the human body, research in recent years has suggested that astronauts may experience some pretty dramatic changes on both the physiological and psychological levels. In the latest study led by a team at University of California San Diego, researchers found signs of accelerated aging in human stem cells that spent roughly a month in space. 

The research focused on hematopoietic stem and progenitor cells (HSPCs), which are crucial in the formation of blood and immune cells. Stem cells were sent to the International Space Station for stays of 32-45 days using specially developed nanobioreactors to monitor them. Another set remained on Earth at the Kennedy Space Center. The cells that went to the ISS showed a host of changes, including reduced self-renewal abilities, greater susceptibility to DNA damage and inflammation in the mitochondria. However, the damage didn't appear to be permanent. The team notes that the changes were at least partially reversed when the cells were removed from the space environment. 

“Space is the ultimate stress test for the human body,” Catriona Jamieson, director of the UC San Diego Sanford Stem Cell Institute, said in a statement. “These findings are critically important because they show that the stressors of space — like microgravity and cosmic galactic radiation — can accelerate the molecular aging of blood stem cells. Understanding these changes not only informs how we protect astronauts during long-duration missions but also helps us model human aging and diseases like cancer here on Earth."