Friday, November 27, 2020

Spaceflight Does Weird Things to the Body

I recently watched and enjoyed a documentary on Netflix about astronaut Scott Kelly's almost-year-long mission to the International Space Station. Kelly, and his twin brother who stayed on Earth, were extensively studied to see how the extended period of zero gravity would affect his body.

The results are in and are quite interesting, and not necessarily in a good way.  

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. 

Of these six changes, the biggest and most surprising one for scientists was mitochondrial dysfunction. Mitochondria play a critical role in producing the chemical energy necessary to keep cells—and by extension, tissue and organs—functional. Researchers found irregular mitochondrial performance in dozens of astronauts and were able to broadly characterize these changes thanks to new genomics and proteomics techniques. Afshin Beheshti, a bioinformatician at NASA and senior author of one study, says mitochondrial suppression helps explain how many of the problems astronauts experiment (like immune system deficiencies, disrupted circadian rhythm, and organ complications) are actually holistically related to each other, since they all rely on the same metabolic pathways.

“When you’re in space, it’s not just one are or organ that’s affected, it’s the whole body that’s affected,” says Beheshti. "We started connecting the dots."

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