Living in space appears to increase an organism’s lifespan, suggests new research on the microscopic worm — Caenorhabditis elegans.
The surprise discovery was made by a group of researchers studying the bone and muscle mass loss experienced by astronauts after extended time in space.
The research was led by Dr Nathaniel Szewczyk, from The University of Nottingham; a part of the ICE-FIRST project which involved scientists from Japan, France, the US, and Canada.
The researchers discovered that time in space suppresses the accumulation of the toxic proteins that normally accumulate within aging muscle tissue. They also found a group of genes that are expressed at much lower levels during spaceflight. “When the expression of these same genes were lowered in worms back on Earth the worms lived longer.”
Dr Szewczyk, an expert in muscle metabolism, said: “We identified seven genes, which were down-regulated in space and whose inactivation extended lifespan under laboratory conditions.”
Asked how these genes may play a role in longevity, Dr. Szewczyk said: “We are not entirely certain, but it would appear that these genes are involved in how the worm senses the environment and signals changes in metabolism in order to adapt to the environment. For example, one of the genes we have identified encodes insulin which, because of diabetes, is well known to be associated with metabolic control. In worms, flies, and mice insulin is also associated with modulation of lifespan.”
And what would this mean for long-term space travelers? He said: “Well, most of us know that muscle tends to shrink in space. These latest results suggest that this is almost certainly an adaptive response rather than a pathological one. Counter-intuitively, muscle in space may age better than on Earth. It may also be that spaceflight slows the process of aging.”
“Dr Szewczyk’s role was to provide expertise in the culturing of worms in CeMM — a special liquid food for worms. Dr Szewczyk transported the samples to and from the Russian launch site and ran a series of ‘health’ checks to ensure that the tiny astronauts were fit for flying. On their return he helped with the analysis of the data.”
“The signals that control muscle protein degradation in the human body. C. elegans is the perfect substitute for studying long-term changes in human physiology because they suffer from muscle atrophy — muscle loss — under many of the same conditions that people do.”
The worm, C. elegans, “was the first multi-cellular organism to have its genetic structure completely mapped and many of its 20,000 genes perform the same functions as those in humans.”
Of the two thousand genes that have a role in promoting muscle function in the worm, 50 to 60 per cent of them have very clear human counterparts.
“When the research began Dr Szewczyk was working at NASA. He is now based at The University of Nottingham’s MRC and Arthritis Research UK Centre for Musculoskeletal Ageing Research.
The experiment in 2004 involved a consignment of live worms being despatched to the International Space Station (ISS) onboard the Dutch DELTA mission.”
The worms used originally come from a garbage dump located in Bristol. The C. elegans there generally feed on decaying fruit and vegetable matter.
The worms have now taken part in five different spaceflights to the ISS, done with the purpose of learning more about how the physiology of the human body is affected by microgravity.
“Notably, in 2003 Dr Szewczyk’s C. elegans made the news when they survived the Space Shuttle Columbia disaster. Living in petri dishes and enclosed in aluminium canisters the worms survived re-entry and impact on the ground and were recovered weeks after the disaster.”
“This spaceflight work teaches us things about the body that we couldn’t learn on Earth. They have led to the publication of research into how to block muscle degradation using a form of gene therapy in PLoS ONE and publication of a muscle repair mechanism in PLoS Genetics. The work on C. elegans has also established that worms can live and reproduce for at least six months in space. This makes it an ideal and cost-effective experimental system to investigate the effects of long duration and distance space exploration as recently reported in Interface, a journal of The Royal Society. Together these missions have established that the team is not only better able to understand how muscle works on Earth but they are also in a position to send worms to other planets and experiment on them along the way.”
“Astronaut now being studied
Another member of the Centre’s team is currently examining the effects of spaceflight upon the muscles of the current European record holder for time spent in space.”
“Andre Kuipers, the Dutch astronaut who flew the mission in 2004, has just returned from ISS with yet another worm experiment from space for the team at Nottingham and is also, himself, being studied.”
“That experiment, led by Professor Marco Narici, is to study the effects of long-duration spaceflight on human muscle.”
The results of the research have just been published in the journal Scientific Reports.
Source and Images: University of Nottingham