Space Travel Accelerates Aging of Human Blood Stem Cells, UC San Diego Study Reveals

Spaceflight accelerates aging of human blood stem cells

University of California - San DiegoSep 4 2025 Researchers from University of California San Diego Sanford Stem Cell Institute have discovered that spaceflight accelerates the aging of human hematopoietic stem and progenitor cells (HSPCs), which are vital for blood and immune system health. In a study published in Cell Stem Cell, the team used automated artificial intelligence (AI)-driven stem cell-tracking nanobioreactor systems in four SpaceX Commercial Resupply Services missions to the International Space Station (ISS) to track stem cell changes in real time. The findings show that the cells lost some of their ability to make healthy new cells, became more prone to DNA damage and showed signs of faster aging at the ends of their chromosomes after spaceflight - all signs of accelerated aging. Space is the ultimate stress test for the human body. 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. This is essential knowledge as we enter a new era of commercial space travel and research in low earth orbit." Catriona Jamieson, M.D., Ph.D., director of the Sanford Stem Cell Institute and professor of medicine at UC San Diego School of Medicine Previous NASA studies have shown that spaceflight can affect immune function and telomere length. One such study - the NASA Twins Study - was a landmark, year-long experiment (2015-2016) where astronaut Scott Kelly spent 340 days aboard the ISS while his identical twin, Mark Kelly, remained on Earth. The study tracked changes across genetics, physiology, cognition and the microbiome and found altered gene expression, shifts in telomere length and changes in the gut microbiome. However, many of these changes reversed or returned to normal after astronaut Kelly returned to Earth. The study did identify some persistent changes, such as increased numbers of short telomeres and disruptions in gene expression, which could be relevant for longer space missions. This UC San Diego-led study builds on the findings of the Twins Study and the seminal work of the Space Omics and Medical Atlas group which published 44 scientific papers on aerospace medicine and space biology in Nature. By focusing specifically on HSPCs, the study provided a detailed mechanistic look at how space triggers molecular aging, something the Twins Study hinted at but could not fully explore at the cellular level. To conduct the study, researchers - including Space Tango - developed a novel "nanobioreactor" platform - miniaturized 3D biosensing systems that allowed human stem cells to be cultured in space and monitored with AI-powered imaging tools. The study's findings: Human HSPCs exposed to 32 to 45 days of spaceflight showed hallmark features of aging. Researchers observed that spaceflight triggers a range of changes in blood-forming stem cells that closely resemble what happens to these cells as we age. The cells became more active than normal, burning through their reserves and losing the ability to rest and recover - a key trait that allows stem cells to regenerate over time. Their ability to make healthy new cells declined, while signs of molecular wear-and-tear, like DNA damage and shorter chromosome ends (telomeres), became more pronounced. The cells also showed signs of inflammation and stress inside their mitochondria - the cell's energy producers - and began activating hidden sections of the genome that are normally kept quiet to maintain stability. These stress responses can impair immune function and increase the risk of diseases. Notably, when these space-exposed cells were later placed in a young, healthy environment, some of the damage began to reverse, suggesting it may be possible to rejuvenate aging cells with the right interventions. These findings have implications not just for astronaut health, but also for understanding the mechanisms of aging and age-related diseases like cancer on Earth. They underscore the need for new countermeasures to protect stem cell function during extended space missions and support the development of biological markers to detect stress-induced aging early. "We're excited this breakthrough work is being published to the wider scientific and space communities," said Twyman Clements, president and co-founder of Space Tango. "Like many accomplishments, this one was a team effort bringing together the Integrated Space Stem Cell Orbital Research Center within SSCI, Space Tango and others. Coupling Space Tango's CubeLab capabilities, specifically the persistent microscopy, has enabled this work and will continue to do so in the future." The research team plans to extend this work with additional ISS missions and astronaut-based studies, focusing on real-time monitoring of molecular changes and potential pharmaceutical or genetic countermeasures to protect human health in space and beyond. To date, the SSCI has conducted 17 missions to the ISS. "Space experiments are so complex that they force you to do better science on the ground," continued Jamieson. "Space research has accelerated technological advancements on Earth, making ground-based research easier and more relevant to human health. What we have learned about cancer from our studies in space is absolutely remarkable." University of California - San Diego Journal reference: Pham, J., et al. (2025). Nanobioreactor detection of space-associated hematopoietic stem and progenitor cell aging. Cell Stem Cell. doi.org/10.1016/j.stem.2025.07.013

Going to space could speed up biological ageing, NASA study finds

Human blood cells that were sent into space began losing their ability to make healthy new cells, in a sign of accelerated ageing, the study found. Going to space could speed up biological ageing, according to new research that tracked changes to human stem cells during four missions in space. The study, which was supported by the American space agency NASA, found that blood cells that were sent to space lost some of their ability to make healthy new cells and started showing genetic damage, both signs of accelerated ageing. "Space is the ultimate stress test for the human body," said Dr Catriona Jamieson, one of the study's authors and director of the Sanford Stem Cell Institute at the University of California San Diego in the United States. Jamieson's team used artificial intelligence (AI)-powered imaging tools to track real-time changes to cultured human cells that were sent on four SpaceX missions to the International Space Station (ISS). They used haematopoietic stem and progenitor cells (HSPCs), which are responsible for blood cell production, making them critical for human health, including immune system function. When these cells stayed in space for 32 to 45 days, they started losing their ability to make healthy new cells, the study found. Signs of molecular erosion, for example DNA damage and shorter telomeres, also become more apparent. "These findings are critically important because they show that the stressors of space - like microgravity and cosmic galactic radiation - can accelerate the molecular ageing of blood stem cells," Jamieson said in a statement. Notably, when these cells returned to Earth and were placed in a healthier environment, some of the damage began to reverse, according to the study, which was published in the journal Cell Stem Cell. The findings underscore the need for new measures to protect astronauts' health during extended space missions, the researchers said. They now plan to study whether the same molecular changes are found in actual astronauts during space missions, with the goal of identifying medical or genetic antidotes that could help protect human health. "Understanding these changes not only informs how we protect astronauts during long-duration missions but also helps us model human ageing and diseases like cancer here on Earth," Jamieson said. "This is essential knowledge as we enter a new era of commercial space travel and research in low Earth orbit".

Spaceflight Accelerates Human Stem Cell Aging, UC San Diego Researchers Find | Newswise

Newswise -- Researchers from University of California San Diego Sanford Stem Cell Institute have discovered that spaceflight accelerates the aging of human hematopoietic stem and progenitor cells (HSPCs), which are vital for blood and immune system health. In a study published in Cell Stem Cell, the team used automated artificial intelligence (AI)-driven stem cell-tracking nanobioreactor systems in four SpaceX Commercial Resupply Services missions to the International Space Station (ISS) to track stem cell changes in real time. The findings show that the cells lost some of their ability to make healthy new cells, became more prone to DNA damage and showed signs of faster aging at the ends of their chromosomes after spaceflight -- all signs of accelerated aging. "Space is the ultimate stress test for the human body," said Catriona Jamieson, M.D., Ph.D., director of the Sanford Stem Cell Institute and professor of medicine at UC San Diego School of Medicine. "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. This is essential knowledge as we enter a new era of commercial space travel and research in low earth orbit." Previous NASA studies have shown that spaceflight can affect immune function and telomere length. One such study -- the NASA Twins Study -- was a landmark, year-long experiment (2015-2016) where astronaut Scott Kelly spent 340 days aboard the ISS while his identical twin, Mark Kelly, remained on Earth. The study tracked changes across genetics, physiology, cognition and the microbiome and found altered gene expression, shifts in telomere length and changes in the gut microbiome. However, many of these changes reversed or returned to normal after astronaut Kelly returned to Earth. The study did identify some persistent changes, such as increased numbers of short telomeres and disruptions in gene expression, which could be relevant for longer space missions. This UC San Diego-led study builds on the findings of the Twins Study and the seminal work of the Space Omics and Medical Atlas group which published 44 scientific papers on aerospace medicine and space biology in Nature. By focusing specifically on HSPCs, the study provided a detailed mechanistic look at how space triggers molecular aging, something the Twins Study hinted at but could not fully explore at the cellular level. To conduct the study, researchers -- including Space Tango -- developed a novel "nanobioreactor" platform -- miniaturized 3D biosensing systems that allowed human stem cells to be cultured in space and monitored with AI-powered imaging tools. The study's findings: Notably, when these space-exposed cells were later placed in a young, healthy environment, some of the damage began to reverse, suggesting it may be possible to rejuvenate aging cells with the right interventions. These findings have implications not just for astronaut health, but also for understanding the mechanisms of aging and age-related diseases like cancer on Earth. They underscore the need for new countermeasures to protect stem cell function during extended space missions and support the development of biological markers to detect stress-induced aging early. "We're excited this breakthrough work is being published to the wider scientific and space communities," said Twyman Clements, president and co-founder of Space Tango. "Like many accomplishments, this one was a team effort bringing together the Integrated Space Stem Cell Orbital Research Center within SSCI, Space Tango and others. Coupling Space Tango's CubeLab capabilities, specifically the persistent microscopy, has enabled this work and will continue to do so in the future." The research team plans to extend this work with additional ISS missions and astronaut-based studies, focusing on real-time monitoring of molecular changes and potential pharmaceutical or genetic countermeasures to protect human health in space and beyond. To date, the SSCI has conducted 17 missions to the ISS. "Space experiments are so complex that they force you to do better science on the ground," continued Jamieson. "Space research has accelerated technological advancements on Earth, making ground-based research easier and more relevant to human health. What we have learned about cancer from our studies in space is absolutely remarkable." Link to full study. Additional co-authors on the study include: Jessica Pham, Jane Isquith, Larisa Balaian, Shuvro P. Nandi, Claire Engstrom, Karla Mack, Inge van der Werf, Patrick Chang, Jana Stoudemire, Luisa Ladel, Emma Klacking, Antonio Ruiz, Daisy Chilin-Fuentes, Jenna Sneifer, Alysson R. Muotri, Thomas Whisenant and Ludmil B. Alexandrov from UC San Diego. David Mays, Paul Gamble, Shelby Giza, Jiya Janowitz, Trevor Nienaber and Twyman Clements from Space Tango. Tejaswini Mishra and Michael P. Snyder from Stanford University School of Medicine. Anna A. Khachatrian from Scripps Health. Elsa Molina and Sheldon R. Morris from The Salk Institute for Biological Studies. The study was funded, in part, by NASA (NRA NNJ13ZBG001N) to UC San Diego Sanford ISSCOR Center; NCI (R01CA205944); NIH/NIDDK (R01DK114468-01); NIH NCI CCSG p30CA023100; NIH NCI CCSG: P30 CA01495; NIH NIA San Diego Nathan Shock Center (P30 AG068635); The Chapman Foundation and the Helmsley Charitable Trust; LLS Blood Cancer Discoveries; Sanford Stem Cell Institute; Koman Family Foundation; JM Foundation and Moores Family Foundation.

Space Travel Accelerates Cellular Aging, Researchers Say

By Deanna Neff HealthDay ReporterMONDAY, Sept. 8, 2025 (HealthDay News) -- Space travel takes a significant toll on the human body, and a new study reveals that it can speed up the aging of crucial blood and immune cells. Researchers from the University of California San Diego found that blood-forming stem cells showed signs of rapid aging after spending just over a month in space. The study used automated artificial intelligence (AI)-driven imaging on four SpaceX supply missions to the International Space Station (ISS) to track astronauts' stem cell changes in real time. The findings were published Sept. 4 in the journal Cell Stem Cell. For the study, scientists developed a novel "nanobioreactor" technology platform to culture human stem cells in real time in the space environment. The cells were then exposed to space flight for more than a month. Over that time, researchers found, the fitness and function of the cells got worse, similar to an aging cell in the cosmic world. "Space is the ultimate stress test for the human body," said Dr. Catriona Jamieson, director of the Sanford Stem Cell Institute at UC San Diego. "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," she added in a news release. The findings build upon previous research, including NASA's groundbreaking Twins Study, which investigated the effects of spaceflight on gene expression and on telomeres, protective structures on chromosomes. This new research provides a more detailed look at how these changes occur at a cellular level. After being in space for 32 to 45 days, the blood stem cells showed several hallmarks of aging. They became overactive, burning through their reserves and losing their ability to rest and regenerate, a key function of stem cells. The cells' ability to produce healthy new cells declined. They also showed increased signs of DNA damage and shorter telomeres, the protective caps at the ends of chromosomes. Chromosomes are structures made of protein and DNA code, and would unravel and lose proper function without the telomeres keeping them intact, according to the National Human Genome Research Institute. These endcaps, or telomeres, also play a role in cancer. Further, the study found signs of inflammation and stress within cells' mitochondria, their energy-producing parts. They also began activating dormant parts of their genetic code, which can harm immune function and increase the risk of disease. Notably, when the space-exposed cells were brought back to Earth and placed in a healthy environment, some of the damage began to reverse. This suggests that it may be possible to develop interventions to protect or even rejuvenate these cells, a key focus of future research. The findings may have practical applications here on Earth, researchers said. Understanding how spaceflight accelerates aging could provide new insights into the aging process and age-related diseases, such as cancer. Researchers plan to continue studying astronauts to try to pinpoint real-time protective health measures during long space missions. Jamieson added that the challenges of space research have a surprising benefit for science on Earth. "Space experiments are so complex that they force you to do better science on the ground," she said. "What we have learned about cancer from our studies in space is absolutely remarkable." More information The National Aeronautics and Space Administration has more about research on the International Space Station. SOURCES: University of California San Diego, news release, Aug. 28, 2025; Cell Stem Cell, Sept. 4, 2025