A fountain of youth pill could be on the horizon after scientists more than DOUBLED the lifespan of the humble earthworm.
What’s more the creepy crawly’s offspring were also healthier – offering hope that longevity would increase “down the generations.”
The British team’s breakthrough involves switching off an ‘ageing’ gene known as DAF-2.
By reducing its expression the roundworm Caenorhabditis elegans lived over twice as long as normal.
This would be like us living up to 200 years.
In animals – including humans – it controls a signalling transmitting liver protein called IGF-1 (insulin-like growth factor 1) found on the membranes of cells.
Lead researcher Dr Alexei Maklakov, a biological scientist at East Anglia University, said: “As expected, we found the worms lived more than two times longer when IGF-1 signalling that ages them was reduced.
“Remarkably, we also found their offspring were fitter and produced more offspring themselves.
“We are really killing two birds with one stone because we are improving the health and longevity of the parents – and the fitness of their offspring.
“This really challenges the classic idea ageing is invariably linked to energy allocation between survival and reproduction.”
The findings published in Evolution Letters could lead us to staying younger and healthier for longer through gene therapy.
The IGF-1 chemical controls an organism’s growth, reproduction and longevity. Reducing its activity has been shown to increase lifespan in many animals.
So the researchers – who included colleagues at Uppsala University in Sweden – allowed the worms to develop and reach maturity before “knocking-down” DAF-2.
Dr Maklakov said: “Understanding how and why we age is fundamental to improving quality of life in an increasingly long-lived society.
“It is often thought we age because of a slow accumulation of unrepaired cellular damage in our bodies – and that ageing is the result of energy trade-offs between growth, reproduction and survival.
“But we now know that switching off the function of certain genes in adulthood can increase longevity without a reproduction cost.
“An emerging new theory is the genes that age us are programmed to make us grow and reproduce in early life, but when their function ‘runs-on’ unabated in later life it starts causing problems.
“If this is true, then we should be able to stay younger for longer by reducing high levels of gene signalling – or ‘shutting down’ these genes in later life.”
It suggests the key to longevity is silencing the DAF-2 gene at just the right point in the life cycle.
In previous experiments by other teams across the world longer life was only achieved at the cost of a loss of ability to reproduce in C. elegans.
Targeting DAF-2 after the worms reached adulthood increased lifespan – without affecting their reproduction.
Interfering with this gene in a similar way could also safely extend the human lifespan, said Dr Maklakov.
Evolutionary biologists have long predicted lifespan can’t be lengthened without a reproductive trade off.
But switching off DAF-2 at the onset of adulthood led to the worms living much longer – and reproducing normally.
It adds to growing evidence the gene controls reproduction during the worm’s developmental phase – and lifespan during its adult life.
Dr Maklakov said: “Our findings support the emerging view that suboptimal gene expression in adulthood lies at the heart of ageing.
“Essentially, our results show that natural selection optimises gene expression in early-life but is not sufficiently strong to optimise gene expression in late-life.
“Ageing can result from accumulation of unrepaired damage with age. However, it can also result simply from suboptimal regulation of gene expression in late-life.
“Understanding the importance of these two processes is important both for our understanding of the evolution of ageing, and for the applied programmes aimed at lifespan extension.
“We want to establish which of the two processes is more prevalent across the tree of life.”
C. elegans is a 1mm long soil-dwelling nematode composed of only 1,000 cells.
It has a lifespan of about three weeks.
But they age in ways that are biochemically and physiologically very similar to our own – making them an ideal animal for studying our own decline.
Like other so-called model organisms used in biomedical research, C. elegans is also strikingly similar to humans at a genetic level.
Its genes are up to 80 per cent the same as ours. The worm has been used for over 40 years to investigate a range of biological processes in humans.
by Mark Waghorn
