Research shows that the four crew members of Inspiration4, the first ever fully civilian space mission, have become genetically younger during their time in space. But the effects didn’t last long. Scientists are now trying to unravel how the space environment affects human DNA.
The Inspiration4 crew members had a packed schedule during their three-day space trip in September 2021. Instead of just floating around in weightlessness and enjoying the breathtaking views from their customized Crew Dragon Resilience space capsule, they lent their bodies to science.
Hayley Arceneaux, the mission’s lead physician and a trained physician assistant, was busy collecting blood samples and skin swabs from herself and her crewmates during their time in orbit. A series of tests followed their return to Earth and continued for several months afterward.
The results of these experiments were published on Tuesday, June 11, in three scientific articles in the journals Nature and Nature Communications. The tests showed that the space environment has fast-acting and profound effects on the human body, which can be detected in markers in blood after just a few hours in orbit.
NASA, JAXA and the European Space Agency have previously conducted similar experiments on astronauts during long-term stays on the International Space Station, but the Inspiration4 mission gave scientists the opportunity to study the earliest stages of these space-induced processes in the human body. .
Related: Inspiration4: The first fully civilian spaceflight on SpaceX Dragon
Chromosome caps become longer
“We’re getting closer to the point where we can almost measure the dose of space on the body,” said Chris Mason, professor of genomics, physiology and biophysics at Weill Cornell Medicine and member of the Scientific Advisory Board at biotechnology company Seer whose Proteograph was used to study the analyze data, Space.com said in an interview. “They had only been in space for a few days, but we could already see early signs of spaceflight exposure on the body, including protein changes and changes in gene expression.”
For example, the researchers noted that markers indicating the aging of DNA decreased in space, making the crew members’ DNA look younger and healthier. These markers, known as telomeres, are caps that protect chromosomes that are known to shorten with age and as a result of environmental factors and stress.
However, the Inspiration4 participants had their telomeres lengthen during the space mission. Scientists previously observed telomere lengthening in NASA astronaut Scott Kelly when they studied the effects of his one-year stay in orbit in 2015 on his body. The findings were surprising even then, as the researchers expected the opposite to happen due to the high stress levels the organism is exposed to in space.
To see these effects in the Inspiration4 crew members after just a few days in space was even more unexpected, according to scientists.
“We saw telomere lengthening in all four crew members,” said Susan Bailey, a professor of radiation cancer biology and oncology at Colorado State University who led the study, during a press conference at the presentation of the papers on Monday, June 10. “It is a truly remarkable finding in a number of respects and helps us consolidate our findings.”
The researchers believe that telomere lengthening is caused as a protective response by exposure to the higher radiation environment of space. Similar effects have been measured in mountain climbers after climbing the world’s highest peaks.
“We think the DNA is equivalent to hormesis,” says Mason, lead author of two of the studies. “It is the effect we see when you strain the body, for example in the gym. Your muscles become sore, but the body responds by building strength.”
However, there’s a catch, Bailey said. After the astronauts return to Earth, the telomeres shrink almost immediately and become shorter than before spaceflight. The researchers, Bailey said, don’t understand what causes the shortening, but hope they can control the reaction in the future.
“It takes several months for the telomeres to recover,” Bailey said. “It’s one of those things that doesn’t quite go back to where you were when you started. We think there is a real opportunity to think about the long-term health outcomes for astronauts once they return to Earth and how we can better monitor this.” and improve that result.”
Shortening the protective telomeres leads to DNA damage and… makes individuals susceptible to a range of diseases, including cancer, heart disease or immune system deficiency. However, research suggests that healthy diets and restorative practices such as meditation can help repair those chromosomal caps.
Similar to astronauts performing a long-duration mission, the Inspiration4 crew members’ bodies showed other signs of aging during spaceflight, including increased signs of bone and muscle loss and brain stress. However, these returned to pre-flight levels within six months. Inspiration4 crew members Hayley Arceneaux and Chris Sembroski, who took part in the briefing, appeared to have no regrets about the deterioration of their telomeres as a result of their space journey.
“I was so happy to be able to contribute to the science and I know it was very important to all our crew members,” Arceneaux said.
Sembroski added: “It is truly humbling and honoring to be part of this investigation. I don’t think any of our crew members really understood the full potential of what this mission would deliver, but it was incredible to see the impact that came from it.”
The study also found that female crew members Arceneaux and geologist Sian Proctor recovered more quickly from the spaceflight, with most of their health markers returning to pre-flight levels faster than those of their male counterparts Sembroski and mission commander and benefactor Jared Isaacman. The results confirm observations in female NASA astronauts and suggest that female bodies may be better suited to withstand the stresses of spaceflight.
The data will be part of an open-access biological data repository for astronauts, the Space Omics and Medical Atlas (SOMA), which is also published as part of the Nature package. The atlas contains data from long-duration space missions conducted by NASA, JAXA and ESA, and is a unique resource that allows researchers to compare and study in detail the many biological, physiological and genetic changes that can occur in humans. during space flights.
The researchers hope that in the future the database will allow them to not only select people who are genetically best suited to endure the rigors of space travel, but also devise strategies to improve outcomes for people who do so. are less suitable for.
“We want to use this data to predict how people will respond to space at a physiological and molecular level,” says Mason. “Ultimately we would like to find ways to increase their response, address some of the changes with a drug and help them so that we don’t exclude anyone from traveling to space.”
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Mason even published a book in 2021 titled “The Next 500 Years: Engineering Life to Reach New Worlds,” in which he advocates genetically engineering humans to make them better suited to explore and settle the solar system. He admits that the current state of knowledge is not sufficient to attempt to engineer astronaut genomes.
“We probably need another 20 years of data before I even think we can make a good estimate of what to do,” Mason said. “But this is the start of mapping out what changes we need to address, what we need to build new drugs around, and what we might one day do.”
The research could also help medical scientists on Earth find treatments for genetic conditions that are ruining the lives of millions of children around the world and for which there is currently no cure.
The three studies in the journal Nature about these spaceflight-induced crew genetic changes can be found here, here And here.