Space Travel Weakens the Heart, New Study Finds

It’s no secret that spending prolonged intervals in area takes a toll on the human physique. For years, NASA and different area companies have been researching the results of microgravity on people, animals, and vegetation aboard the International Space Station (ISS). Thus far, the analysis has proven that being in area for lengthy intervals results in muscle atrophy, bone density loss, adjustments in imaginative and prescient, gene expression, and psychological points. Figuring out these results and learn how to mitigate them is crucial given our future area exploration objectives, which embrace long-duration missions to the Moon, Mars, and past.

Nevertheless, based on a recent experiment led by researchers at Johns Hopkins College and supported by NASA’s Johnson House Middle, it seems that coronary heart tissues “actually don’t fare nicely in area” both. The experiment consisted of 48 samples of human bioengineered coronary heart tissue being despatched to the ISS for 30 days. As they point out in their paper, the experiment demonstrates that publicity to microgravity weakens coronary heart tissue and weakens its means to keep up rhythmic beats. These outcomes point out that further measures should be taken to make sure people can preserve their cardiovascular well being in area.

The examine was led by Deok-Ho Kim and his colleagues from the Department of Biomedical Engineering at Johns Hopkins College (BME-JHU) and the JHU Center for Microphysiological Systems. They had been joined by researchers from UC Boulder’s Ann and HJ Smead Department of Aerospace Engineering Sciences, the Institute for Stem Cell & Regenerative Medicine (ISCRM) and the Center for Cardiovascular Biology on the College of Washington, the Stanford Institute for Stem Cell & Regenerative Medicine, BioServe Space Technologies, and NASA’s Johnson House Middle. The paper that particulars their findings was revealed yesterday (September twenty third) within the Proceedings of the National Academy of Sciences.

Earlier analysis has proven that astronauts returning to Earth from the ISS undergo from a myriad of well being results in keeping with sure age-related situations, together with diminished coronary heart muscle operate and irregular heartbeats (arrhythmias), most of which can dissipate over time. Nevertheless, none of this analysis has addressed what occurs on the mobile and molecular degree. To study extra about these results and learn how to mitigate them, Kim and his colleagues despatched an automatic “heart-on-a-chip” platform to the ISS for examine.

To create this payload, the crew relied on human-induced pluripotent stem cells (iPSCs), which may turn out to be many sorts of cells, to provide cardiomyocytes (coronary heart muscle cells). These ensuing tissues had been positioned in a miniaturized bioengineered tissue chip designed to imitate the surroundings of an grownup human coronary heart. The chips would then accumulate information on how the tissues would rhythmically contract, imitating how the guts beats. One set of biochips was launched aboard the SpaceX CRS-20 mission to the ISS in March 2020, whereas one other was saved on Earth as a management group.

As soon as on the ISS, astronaut Jessica Meir tended the experiment, altering the liquid vitamins surrounding the tissues as soon as every week whereas preserving tissue samples at particular intervals so gene readout and imaging analyses could possibly be carried out upon their return to Earth. In the meantime, the experiment despatched real-time information again to Earth each half-hour (for 10 seconds at a time) on the tissue samples’ contractions and any irregular beating patterns (arrhythmias).

“An unimaginable quantity of cutting-edge expertise within the areas of stem cell and tissue engineering, biosensors and bioelectronics, and microfabrication went into making certain the viability of those tissues in area,” mentioned Kim in a latest Hub news release.

When the tissue chambers returned to Earth, he and his colleagues continued to keep up and accumulate information from the samples to see if there was any change of their skills to contract. Along with shedding energy, the muscle tissues developed arrhythmias, in keeping with age-related coronary heart situations. In a wholesome human coronary heart, the time between beats is a couple of second, whereas the tissue samples lasted almost 5 occasions as lengthy – although they returned to just about regular as soon as returned to Earth.

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The crew additional discovered that the tissue cell’s protein bundles that assist them contract (sarcomeres) had been shorter and extra disordered than these of the management group, one other symptom of coronary heart illness. What’s extra, the mitochondria within the tissue samples grew bigger and rounder and misplaced the attribute folds that assist them produce and use vitality. Lastly, the gene readout within the tissues confirmed elevated gene manufacturing associated to irritation and an imbalance of free radicals and antioxidants (oxidative stress).

This isn’t solely in keeping with age-related coronary heart illness but in addition persistently demonstrated in astronauts’ post-flight checks. The crew says these findings increase our scientific data of microgravity’s potential results on human well being in area and will additionally advance the examine of coronary heart muscle getting older and therapeutics on Earth. In 2023, Kim’s lab adopted up on this experiment by sending a second batch of tissue samples to the ISS to check medication that might assist defend coronary heart muscle mass from the results of microgravity and assist folks preserve coronary heart operate as they age.

In the meantime, the crew continues to enhance its tissue-on-a-chip system and has teamed up with NASA’s Space Radiation Laboratory to review the results of area radiation on coronary heart muscle mass. These exams will assess the menace photo voltaic and cosmic rays pose to cardiovascular well being past Low Earth Orbit (LEO), the place Earth’s magnetic discipline protects in opposition to most area radiation.

Additional Studying: John Hopkins University, PNAS