How does spaceflight affect humans on the molecular level? This is what a recent study published in iScience hopes to address as a team of researchers from the University of Surrey investigated the alteration of human genes over prolonged periods of simulated microgravity. This study holds the potential to help astronauts, scientists, and the public better understand the long-term effects of spaceflight as human space exploration continues to ramp up throughout the 2020s and beyond.
For the study, the researchers enlisted 20 male participants for a 60-day bed rest experiment where they were positioned in a six-degree head-down angle to simulate the microgravity environment that astronauts experience while in space. The head-down portion of the study was vital since due to the bodily fluids that migrate to an astronaut’s upper body during spaceflight, more commonly known as “puffy face”. The 60-day bed rest trial was precluded by a two-period of establishing a baseline for each participant, followed by a two-week recovery period after the bed rest was concluded.
In the end, the researchers discovered the participants’ gene expression, or the gene’s primary information, was altered by as much as 91 percent during the 60-day bed rest period, along with 76 percent of this alteration remaining 10 days into the two-week recovery period. The study notes how these findings could have implications for advancing our knowledge of the health impacts of long-term spaceflight.
Image of Expedition 67 crew members with floating fresh fruit in microgravity that had been delivered by the Progress 81 cargo craft. (Credit: NASA)
"This unique study represents the largest longitudinal dataset of time series gene expression in humans,” said Dr. Simon Archer, who is a Professor of Molecular Biology of Sleep at the University of Surrey and lead author of the study. “Human gene expression varies rhythmically over the 24-hour day, and it is important to collect time series data rather than from just single time points to get a full picture of what occurs in the body when exposed to simulated microgravity. It also raises questions about the impact of constant bed rest on our bodies as we have identified a dramatic effect on the temporal organization of human gene expression."
This study comes as NASA is planning to land the first woman and person of color on the lunar surface before the end of the decade with its Artemis program, along with the private Axiom Space Station scheduled to begin orbital assembly within the next year or two.
What new discoveries will researchers make about the long-term health impacts of spaceflight, specifically pertaining to the microgravity environment, in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: iScience, National Air and Space Museum, EurekAlert!, NASA, Axiom Space
