While we are on the topic of research conducted by astronauts on the International Space Station (ISS), Space X’s 19th resupply mission to the ISS included studies that might help prevent muscle loss in astronauts as well as humans on Earth. While exercise programs have been developed for astronauts, these programs may not be as useful for long-distance space travel – such as a trip to Mars.
This is where scientists at The Jackson (JAX) Laboratory and Professor Se-Jin Lee (JAX Labs and U Connecticut School of Medicine) come in. They sent a group of ‘Mighty Mice’ to the International Space Station for 4 weeks to see whether these mice maintain their muscles in microgravity. Mighty Mice are genetically engineered to lack a protein called myostatin, which was discovered by Dr. Lee as being responsible for putting the brakes on muscle growth. Without this protein, these mice become mighty muscular. In fact, they reportedly develop twice the muscle mass of non-modified mice.
With the help of the astronauts on board the ISS (including astronauts Jessica Meir and Christina Koch), the team found that Mighty Mice maintain muscle mass in space in comparison to non-modified mice that lost both muscle mass and bone mineral density. Another group of non-genetically modified mice were treated with a drug called ACVR2B/Fc that inhibits myostatin as well as another protein involved in muscle loss called activin A. Similar to the Mighty Mice, these treated mice also maintained more muscle as well as bone density than the untreated animals. These findings may lead to a treatment to prevent muscle and bone loss in astronauts planning to stay in space for awhile.
You can check out some of the other experiments that were on board in this YouTube video:
S-J Lee, A Lehar, JU Meir, C Koch, A Morgan, LE Warren, R Rydzik, DW Youngstrom, H Chandok, Joshy George, J Gogain, M Michaud, TA Stoklasek, Y Liu, EL Germain-Lee. Targeting myostatin/activin A protects against skeletal muscle and bone loss during spaceflight. PNAS. 117(38):23942-23951, 2020.