The worm, Caenorhabditis elegans, has been to deep space and back.
Credit: Gurdon Institute
LONDON: Blasting millions of worms into outer space has provided greater insight into the health risks associated with human space travel and could help develop treatments against them.
The microgravity environment of space has many physiological effects on the human body such as loss of, or changes to, muscle formation and strength. As a result astronauts need to exercise for over two hours a day when out in space in order to compensate.
But a recent study published in the journal PLoS one has shown how the process of RNA interference, a technique in which the activity of specific genes can be controlled and regulated, could be used as a promising technique against these muscular changes.
RNAi for long distance travel
RNAi is a commonly used technique to control gene activity in many organisms and is already in use in research to fight a variety of diseases and illnesses here on Earth, such as asthma and cancer.
Researchers from the University of Nottingham in the UK sent samples of the worm Caenorhabitis elegans (C. elegans) into space onboard the space shuttle Atlantis where they were then treated with RNAi once in orbit onboard the International Space Station.
Many of the genes found in c.elegans perform the same function in humans making the worms a good model for gene activity changes in astronauts.
"There were really two things we were looking at; the ability of RNAi to decrease gene expression in space and any muscle degradation seen in the worms" explained Nathaniel Szewczyk, who worked on the study. "One of the key points seen is that RNAi works on long-distance travel and can be made on demand and for any protein you want".
Protein synthesis or protein degradation?
The samples were analysed for changes in muscle mass as well as other factors once returned to Earth after eight days in spaceflight. Those treated with RNAi to prevent muscle loss showed a reduction in muscle degradation.
However, to translate the findings for use in humans, a lot more needs to be understood about why these changes are seen in muscle during space travel as it is not quite known if muscle is degraded or prevented from being made in the first place.
"We're not entirely convinced that protein degradation goes up in space," continued Szewczyk. " With RNAi we can target different things by affecting protein synthesis in different ways. In order to move forward we need to understand what is affected - protein synthesis or protein degradation."
Key tool in future space healthcare
The research proves that RNAi is a viable technique for use in space. A further challenge would be to investigate the technique out in deep space.
"The next step would be to send worms on satellites outside of the realms we have seen biologically or off on payloads to other planetary bodies," said Szewczyk. This insight will help explore the possibility of manned space missions further out into space than currently allowed.
"The fact that RNA interference remained effective upon muscle-related gene expression gives hope to a range of measures and mechanisms that may now be tested to see if muscle wasting can be slowed or even reversed to the benefit of humans in space, or on Earth," added David Green, an aerospace physiology expert from Kings College London.
"RNAi is a new technique with much work to do but it could become a key tool in the healthcare of the future."
