A groundbreaking study from the University of California San Diego Sanford Stem Cell Institute has revealed that spaceflight significantly accelerates the aging process in human hematopoietic stem and progenitor cells (HSPCs). These cells are crucial for maintaining blood and immune health. The research, published in Cell Stem Cell, utilized advanced AI-driven nanobioreactor systems deployed on four SpaceX resupply missions to the International Space Station (ISS).
The findings indicate that HSPCs exposed to spaceflight for 32 to 45 days exhibited accelerated aging markers. These included a diminished capacity to produce healthy new cells, increased susceptibility to DNA damage, and shortened telomeres, which are protective caps on chromosomes that typically shorten with age. Dr. Catriona Jamieson, director of the Sanford Stem Cell Institute, described space as "the ultimate stress test for the human body," attributing these molecular aging changes to stressors like microgravity and cosmic radiation.
This research builds upon previous findings from NASA's Twins Study, which observed changes in gene expression and telomere length in astronaut Scott Kelly during his year-long mission on the ISS. The UCSD study further revealed that space-exposed HSPCs became hyperactive, depleting their reserves and losing their ability to enter a quiescent state vital for regeneration. This hyperactivity, combined with increased inflammation and mitochondrial stress, destabilized the cells.
While some observed damage showed signs of reversal when the cells were returned to an Earth-like environment, the study also noted that spaceflight induced five times more mutations than ground-based radiation exposure at similar doses. The implications extend beyond astronaut health, as the accelerated aging in HSPCs mirrors processes seen in age-related diseases and cancer on Earth. Understanding these mechanisms could lead to new therapeutic strategies for conditions involving stem cell dysfunction. As commercial space travel expands, this knowledge is vital for ensuring astronaut safety and advancing our comprehension of fundamental biological processes.