Bioengineered heart samples on ISS confirm that weightlessness weakens and ages the heart
Using 48 bioengineered heart samples that spent 30 days on ISS in 2020, scientists have confirmed other research that showed weightlessness not only weakens the heart, it ages it as well.
In addition to losing strength, the heart muscle tissues in space developed irregular beating (arrhythmias)—disruptions that can cause a human heart to fail. Normally, the time between one beat of cardiac tissue and the next is about a second. This measure, in the tissues aboard the space station, grew to be nearly five times longer than those on Earth, although the time between beats returned nearly to normal when the tissues returned to Earth.
The scientists also found, in the tissues that went to space, that sarcomeres—the protein bundles in muscle cells that help them contract—became shorter and more disordered, a hallmark of human heart disease. In addition, energy-producing mitochondria in the space-bound cells grew larger, rounder and lost the characteristic folds that help the cells use and produce energy.
Finally …[t]he tissues at the space station showed increased gene production involved in inflammation and oxidative damage, also hallmarks of heart disease.
None of this is ground-breaking, as it confirms numerous other past studies. What it does do however is confirm that long-term weightlessness is not good for a person’s heart. Many studies have shown that these issues mostly go away once astronauts return to Earth, but for any journey to Mars, involving two years in weightlessness, this data suggests the health risks will be far higher.
Using 48 bioengineered heart samples that spent 30 days on ISS in 2020, scientists have confirmed other research that showed weightlessness not only weakens the heart, it ages it as well.
In addition to losing strength, the heart muscle tissues in space developed irregular beating (arrhythmias)—disruptions that can cause a human heart to fail. Normally, the time between one beat of cardiac tissue and the next is about a second. This measure, in the tissues aboard the space station, grew to be nearly five times longer than those on Earth, although the time between beats returned nearly to normal when the tissues returned to Earth.
The scientists also found, in the tissues that went to space, that sarcomeres—the protein bundles in muscle cells that help them contract—became shorter and more disordered, a hallmark of human heart disease. In addition, energy-producing mitochondria in the space-bound cells grew larger, rounder and lost the characteristic folds that help the cells use and produce energy.
Finally …[t]he tissues at the space station showed increased gene production involved in inflammation and oxidative damage, also hallmarks of heart disease.
None of this is ground-breaking, as it confirms numerous other past studies. What it does do however is confirm that long-term weightlessness is not good for a person’s heart. Many studies have shown that these issues mostly go away once astronauts return to Earth, but for any journey to Mars, involving two years in weightlessness, this data suggests the health risks will be far higher.
