Astronaut Scott Kelly famously lived and worked on the International Space Station for 340 days—the longest time an American has spent in space. His mission gave scientists some vital insight into what happens to the human body during long-duration stays in orbit. That’s because Kelly has an identical twin, Mark (also an astronaut, and now soon to be a US senator). The Kelly twins offered scientists a rare opportunity: as they studied what happened to Scott’s body during his year in space, they had the benefit of a control subject, Mark, who stayed on Earth.
The NASA Twins Study provided more evidence for what we already suspected. In a confined capsule under microgravity and prolonged exposure to radiation, the immune system takes a hit, the eye changes shape for the worse, and there’s some significant loss in muscle and bone mass.
But we also learned about some surprising effects. Kelly experienced changes in his gut microbiome, his cognitive abilities slowed down, certain genes would turn off and on, and his chromosomes experienced structural changes.
“The Twins Study gave us a first sketch of the human body’s molecular responses to spaceflight, but these outlines needed to be filled in,” says Christopher Mason, an associate professor of physiology and biophysics at Weill Cornell Medicine. “The changes we saw needed more context and replication. We needed additional studies to map out the frequency of the changes we observed in other astronauts, and other organisms, that go into space, and also to see if the degree of change was similar for shorter missions.”
That brings us to a new package of research that builds on the Twins Study, reanalyzing some of the original data with new techniques and providing comparisons with other astronauts. In a set of 19 studies published today in a slew of different journals (along with 10 preprints still under peer review), researchers like Mason (a senior author on several of the papers) studied the physiological, biochemical, and genetic changes that occurred in 56 astronauts (including Kelly) who have spent time in space—the largest study of its kind ever conducted.
The new papers, which incorporate results from cell-profiling and gene-sequencing techniques that have become easier to run only recently, reveal that “there are some features of spaceflight that consistently appear in humans, mice, and other animals when they go to space,” says Mason. “There appears to be a core mammalian set of adaptations and responses to the rigors of spaceflight.”
The researchers highlight six biological changes that occur in all astronauts during spaceflight: oxidative stress (an excessive accumulation of free radicals in the body’s cells), DNA damage, dysfunction of the mitochondria, changes in gene regulation, alterations in the length of telomeres (the ends of chromosomes, which shorten with age), and changes in the gut microbiome.
By: Neel Patel
Title: Spaceflight does some weird things to astronauts’ bodies
Sourced From: www.technologyreview.com/2020/11/25/1012628/spaceflight-astronauts-bodies-genetics-effects-scott-kelly-twins-study/
Published Date: Wed, 25 Nov 2020 16:00:07 +0000
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