Mitochondrial changes key to human health problems in space

Living in space is not easy. There are notable impacts on the biology of living things in the harsh environment of space. A team of scientists has now identified a possible driver behind these impacts: the cell’s powerhouse, called mitochondria, experiences changes in activity during space flight.

Recently published in the magazine Cell, these results used data collected over decades of experimental research on the International Space Station, including samples from 59 astronauts. Studies like these are critical to understanding the effects of low gravity, radiation, confined spaces, and more NASA send astronauts into the depths of space for extended missions to the moon, Mars, and beyond.

“We have found a universal mechanism that explains the kinds of changes we see to the body in space, and in a place that we didn’t expect,” said Afshin Beheshti, the lead author of the article and a researcher at the KBR, who provides support to NASA’s Ames Research Center in California’s Silicon Valley. “Everything gets kicked out and it all starts with the mitochondria.”

The research also used a comprehensive database of animal studies collected on the GeneLab platform at Ames, as well as NASA’s twin study comparing identical twins Mark and Scott Kelly over the course of a year. The GeneLab platform is the first of its kind to capture large amounts of space biology “omics” data that can be used to characterize and quantify biological molecules, such as DNA, RNAand proteins – and their systematic effects on the structures and functions of organisms. GeneLab’s analysis working group brought together scientists from around the world to collaborate on the study and get the most out of the data contained in the open source platform.

Mitochondria are tiny structures within cells that produce energy for the basic units of biology that make up our body. When energy production is interrupted, many of the body’s key organs and its immune system can be jeopardized. This new research indicates that this disruption of mitochondrial activity could contribute to the health or performance challenges faced by humans in space.

The first clue to the connection between mitochondria and spaceflight came from research using rodents.

“When we started comparing the tissues of mice that had flown on separate space missions, we noticed that mitochondrial dysfunction kept appearing,” Beheshti said. “Whether we were looking at eye or liver problems, the same pathways linked to the mitochondria were the source of the problem.”

NASA data on humans confirmed this hypothesis. The changes identified in astronaut Scott Kelly’s immune system during his year in space starting in 2015 can also be explained by the observed changes in the activity of his mitochondria. Blood and urine samples from dozens of other astronauts showed further evidence that, in various cell types, being in space led to altered mitochondrial activity.

“This is a big step towards understanding how our bodies can live healthily out of this world,” Beheshti said. “And the good news is that this is a problem we can already start addressing. To begin, we can look at the countermeasures and drugs we already use to address mitochondrial disorders on Earth to see how they might work in space. “

From far-reaching issues like disrupted circadian rhythms to cardiovascular alterations, scientists can now turn to this small but essential structure in cells as a place to continue research and seek solutions. Mitochondria are truly the powerhouse of the cell and could also fuel the future of space biology research, pointing the way to discoveries that will help astronauts live safely in orbit and beyond.

Read New insights into the health effects of long-duration spaceflight for more information on how spaceflight affects astronauts.

Reference: the biology of space flight, Cell.