All astronauts and cosmonauts who’ve been in space a long time found out, or knew in advance, that space travel does not-so-nice things to the human body. Decades of experience show that being in space reduces your muscle mass and your bone density. Even vigorous exercise can’t prevent it all. There are also changes in the heart and the cardiovascular system, including irregular heartbeat.
Maybe all of these adverse changes resolve after time back on Earth. Finding out just what changed is rather tricky; you can’t do a heart biopsy readily on an astronaut before and after space flight. So, Deok-Ho Kim and colleagues at the Johns Hopkins University sent engineered heart tissue to the Space Station. It’s also called a heart organoid, made from tissue culture of heart cells (these are models for developing analyses and treatments of organ pathology).
In the heart organoid the researchers found changes in inflammation pathways. They also found reductions in the energy production by mitochondria in heart cells and some disorder in proteins for heart contraction. In other studies, space travel led to damage in the kidneys, which are notably sensitive to cosmic rays. These phenomena point to us as well suited to conditions on Earth and unlikely colonizers of any other place.
This has been an outreach activity of the Las Cruces Academy, viewable at GreatSchools.org.
Source: Nature, 3 Oct. 2024, pp. 17-18 and Proc. Natl. Acad. Sci. USA, 121, e2404644121, 2024.
