Space flight research sheds light on age-related muscle decline

Space flight research sheds light on age-related muscle decline

Sarcopenia, a progressive and widespread decline in muscle mass and strength, is common in aging and is estimated to affect up to 50% of people ages 80 and older. It can result in disability and injury from falls and is associated with lower quality of life and increased mortality. Aside from lifestyle changes, there is no clinical treatment for sarcopenia.

Space flight, with the associated absence of gravity and limited loading of muscles, results in muscle weakness, a prominent feature of sarcopenia, within a short period of time and provides a temporal overview of age-related atrophy-associated changes in muscle. This relatively short time window in space provides a microgravity model for muscle aging and opens the possibility of studying sarcopenia, which typically takes decades to develop in patients on Earth.

To understand the changes in muscles in microgravity, Siobhan Malany, Maddalena Parafati and their team from the University of Florida, USA, developed skeletal muscle microtissues from donor biopsies and launched them to the International Space Station (ISS) on Spacex CRS-25. Their results were published today inStem Cell Reports. The microtisses were collected from both young, active donors and older, sedentary donors and cultured in an automated mini-laboratory that, in addition to regular feeding and monitoring of the cultures, also enabled electrical stimulation to simulate training. On Earth, the contractile strength of microtissuses from young, active individuals was almost twice the strength of tissues from older, sedentary individuals. After just two weeks in space, muscle strength in the young tissues tended to decrease and was now comparable to the strength of old tissues. A similar trend was observed for muscle protein content, which was higher in young microtissuses on Earth compared to ancient microtissuses, but was reduced in microgravity to levels measured in ancient tissues. In addition, spaceflight altered gene expression, particularly in the younger microtissuses and disrupted cellular processes related to normal muscle function. Interestingly, electrical stimulation could attenuate these changes in gene expression to some extent.

Using electrical pulses to trigger real-time muscle contractions in space, we can simulate training and observe how it helps protect against rapid muscle weakening caused by microgravity. This technological advancement offers insight into how we can maintain muscle health during long space missions and ultimately combat age-related muscle loss here on Earth. “

Siobhan Malany, one of the principal investigators

This study demonstrates that sarcopenia muscle wasting can be modeled in space within a relatively short period of time, paving the way for follow-up studies on causes and potential treatments for sarcopenia from aging or space travel.

Sources: