Can exposure to a space environment affect how quickly an organism ages? A study of the nematode, Caenorhabditis elegans, suggests that in this organism, spaceflight may suppress the formation of transgenically expressed polyglutamine aggregates, which have been shown previously to accumulate with age. The study, published in Scientific Reports, suggests that ageing in C. elegans may be slowed through neuronal and endocrine responses to cues from the space environment.
Lifespan and ageing rates in animals are influenced by environmental factors, such as temperature, oxygen and food intake. How microgravitational space environments affect ageing remains poorly understood and can be difficult to evaluate. To address this question, Yoko Honda and colleagues examined a marker of ageing in space-flown C. elegans and explored the involvement of genes whose expression was altered in spaceflight on the control of lifespan.
During the International C. elegans Experimental First project, worms were incubated and flown for two days and were on board the International Space Station for nine days, before returning to Earth and being flash frozen in liquid nitrogen; control animals underwent the same procedures at the same time on the ground. The authors observed that inactivation of each of seven genes that are downregulated in space extended the worms’ lifespan on the ground. These genes encode proteins that are linked to neuronal or endocrine signalling; most appear to mediate lifespan control through the key longevity-regulating transcription factors DAF-16 or SKN-1 or through dietary-restriction signalling.
Further study of the effects of decreased expression of the implicated genes comparable to the level in spaceflight is required, but the present study suggests that space-flown worms age more slowly compared with the control group, and hints that spaceflight may extend worm lifespan.