Worms in space clarify muscle atrophy

U. NOTTINGHAM (UK) — Microscopic worms may hold clues to overcoming threats posed to human health by space travel and also help find ways to stop muscle degradation in the sick and elderly.

C. elegans were flown into space on board the Space Shuttle Atlantis and spent 11 days in orbit onboard the International Space Station more than 200 miles above the earth.

Many of the worm’s 20,000 genes perform the same functions as those in humans so researchers wanted to study the effectiveness of RNA interference (RNAi), a tried and tested technique which regulates gene expression in diseased tissue, and whether this technique could be employed to reduce or control the dramatic muscle loss experienced by astronauts during spaceflight.

The research, published in the journal PLoS One, shows that RNAi, which is already the subject of more than a dozen clinical trials to target illnesses ranging from cancer to asthma, functions normally in space flight and could be used as a viable option to treat and control muscle degradation.

The findings will not only be of use to astronauts but also to people suffering from waste of muscle due to illness and old age.

“It was really a quite straightforward experiment. Once the worms were in space the scientists onboard the International Space Station treated them with RNAi and then returned them to us for post flight analysis,” says Nathaniel Szewczyk from the division of clinical physiology at the University of Nottingham.

“These results are very exciting as they provide a valuable experimental tool for spaceflight research and clearly demonstrate that RNAi can be used effectively to block proteins which are needed for muscle to shrink.”

During the flight a series of experiments were carried out by Japanese scientists onboard the International Space Station. When the flight samples were returned to Nottingham the results were analysed by Dr Timothy Etheridge, in the Division of Clinical Physiology.

“We were very pleased that, given the numerous problems associated with conducting research in space, our experiments went as planned and allowed us to demonstrate that this form of gene therapy works effectively during spaceflight,” Etheridge says.

“The unexpected finding that RNAi can effectively block protein degradation in muscle in space was also a very welcome surprise.”

The experiment was part of the Japanese CERISE payload to investigate the genetic basis of muscle atrophy and how physical forces prevent muscle wasting. The recently installed Kibo lab is being used for the study of biomedicine and material sciences making use of the weightless conditions experienced in orbit.

Funding was provided by the National Institutes of Health and the Medical Research Council.

More news from University of Nottingham: http://communications.nottingham.ac.uk/News.html