Humans are not built for space. That fact becomes most obvious when astronauts return to Earth with atrophied muscles, weakened bones, cardiovascular problems, and some immune deficiencies. And it seems we also age faster in space, too.
A in the Federation of American Societies for Experimental Biology (FASEB) Journal revealed that microgravity in space accelerates biological aging by affecting cells known as endothelium. Dysfunction of these cells, which line the interior of blood vessels, are commonly seen in age- and space-related diseases.
A team from the Institute of Molecular Science and Technologies in Milan, Italy, led by researcher Silvia Bradamante, studied the effect of microgravity on these cells aboard the International Space Station. The cells were taken from the veins of human umbilical cords. After conducting deep gene expression and protein analysis experiments and comparing the affects of microgravity on the ISS cells versus earthbound cells, researchers found that space-bound cells exhibited dysfunction and inflammation, proving how essential gravity is to human bodily function.
Microgravity triggers TXNIP, a stress-responsive gene that plays an important role in age-related diseases, according to the report. This, combined with mitochondrial dysfunction, alters endothelial behavior, putting the aging process in fast-forward. Those endothelial cells are the "common denominator" for a number of space-related biological problems like vascular disease and bone loss.