A Groundbreaking Insight into Aging: Space Exploration’s Role in Understanding Human Biology
In May 2023, the Axiom-2 mission sent a four-member team of astronauts into space for ten days, during which they conducted a series of experiments aimed at deciphering the complexities of human physiology. The findings from these experiments, recently published in the journal Aging Cell (available at https://onlinelibrary.wiley.com/doi/10.1111/acel.70360), showcase space travel as an extraordinary opportunity to study the aging process and cellular resilience. These insights not only advance our understanding of biological aging but also pave the way for potential anti-aging treatments, even for those who may never venture into space themselves.
Astronauts face a unique set of environmental challenges while in orbit, including microgravity, exposure to ionizing radiation, disruptions to their circadian rhythms, and heightened feelings of social isolation. By analyzing blood samples collected before, during, and after the Axiom-2 mission, researchers from Buck Institute, in collaboration with Weill Cornell Medicine in New York City and King Faisal Specialist Hospital in Jeddah, Saudi Arabia, developed a concept they termed Epigenetic Age Acceleration (EAA). This formula assesses how these stressors influence gene expression and alter biological age. Remarkably, they found that EAA increased by an average of 1.91 years by the seventh day of the mission. However, upon returning to Earth, all crew members exhibited a decrease in biological age, with older astronauts reverting to pre-flight estimates and younger astronauts demonstrating a biological age even lower than what was measured before their journey.
"These findings suggest an exciting possibility that humans possess inherent rejuvenation mechanisms capable of countering the age-accelerating effects of space travel," stated Dr. David Furman, an associate professor and Director of the AI and Bioinformatics Core at Buck. His lab has developed techniques to replicate the impacts of microgravity on cells and organoids. "By utilizing spaceflight as a platform to investigate the mechanisms underlying aging, we can work towards identifying and enhancing these rejuvenating factors, benefiting both astronauts and those of us aging in more typical environments."
The research team employed 32 different DNA methylation-based clocks to analyze the blood samples, led by Matias Fuentealba, PhD, a postdoctoral researcher and bioinformatician at Buck. They discovered that changes in the composition of immune cells significantly contributed to the observed acceleration in biological age, primarily due to alterations in regulatory T-cells and naïve CD4 T-cells. Even after accounting for changes in cell types, predictors of chronological age still indicated acceleration during the astronauts’ time in space. "This indicates that space travel induces rapid yet reversible epigenetic modifications that differ from mere shifts in cell composition," remarked Dr. Furman. He emphasized, "This positions space exploration as a valuable environment for studying aging mechanisms and testing interventions aimed at promoting longevity."
To further explore the implications of microgravity, Dr. Furman is modeling its effects in his lab using organoids derived from heart, brain, and immune cells. Additionally, some patented technology developed at Buck has been transitioned into a company focused on creating tools and assays for drug discovery, targeting individuals interested in intervening in the aging process.
CITATION: Astronauts as a Human Aging Model: Epigenetic Age Responses to Space Exposure
DOI: 10.1111/acel.70360
Additional Coauthors: The research also involved contributions from Christopher Mason, JangKeun Kim, Jeremy Wain Hirschberg, and Eliah G. Overbey from the Department of Physiology and Biophysics at Weill Cornell Medicine, and Bader Shirah from the Department of Neuroscience at King Faisal Specialist Hospital & Research Centre in Jeddah, Saudi Arabia.
Conflict of Interest: Dr. David Furman is a co-founder of Cosmica Biosciences. The other authors have declared no competing interests.
About the Buck Institute for Research on Aging
At the Buck Institute, our mission is to eliminate the threat posed by age-related diseases for current and future generations. We gather talented and passionate scientists from diverse fields to explore the mechanisms of aging and discover new therapeutics that can slow down this process. Our aspiration is to extend the healthy years of life, known as health span. Located just north of San Francisco, we are internationally recognized as leaders in the pursuit of strategies to combat aging, which is the primary risk factor for severe diseases like Alzheimer’s, Parkinson’s, cancer, macular degeneration, heart disease, and diabetes. At Buck, we strive to help individuals live healthier for longer. Our achievements could ultimately reshape healthcare. For more information, visit us at: https://buckinstitute.org.
