Wrinkles, grey hair and niggling aches are seen – and felt – as an inevitable part of growing older, but scientists now claim the ageing process may be reversible.
A team from the respected Salk Institute in La Jolla, California, showed a new gene therapy produced a remarkable rejuvenating effect in mice.
After six weeks of treatment, the animals looked younger, had straighter spines and better cardiovascular health, healed quicker when injured, and lived 30% longer.
The findings are published in the journal Cell today.
Juan Carlos Izpisua Belmonte, who led the work, said: “Our study shows that ageing may not have to proceed in one single direction. With careful modulation, ageing might be reversed.”
The techniques do not lend themselves to immediate use in humans, and the team predicts genuine anti-ageing creams are 10 years away.
However, the discovery raises the prospect of a new approach to healthcare in which ageing is treated, rather than diseases associated with it.
The findings also challenge the notion that ageing is simply the result of physical wear and tear over the years.
They add to growing evidence that ageing is partially – perhaps mostly – driven by an internal genetic clock that actively causes our body to enter a state of decline.
The scientists are not claiming ageing can be eliminated. They say that in the foreseeable future, treatments designed to slow this internal clock could increase life expectancy.
“We believe that this approach will not lead to immortality,” said Izpisua Belmonte. “There are probably still limits that we will face in terms of complete reversal of ageing. Our focus is not only extension of lifespan but most importantly health-span.”
Wolf Reik, a professor of epigenetics at the University of Cambridge who was not involved in the work, described the findings as “pretty amazing” and agreed the idea of life-extending therapies was plausible.
“This is not science fiction,” he said.
The treatment given to the mice was based on a technique that has previously been used to “rewind” adult cells, such as skin cells, back into powerful stem cells, similar to those seen in embryos.
Called induced pluripotent stem (iPS) cells, these have the ability to multiply and turn into any cell type in the body and are being tested in trials designed to provide “spare parts” for patients.
The latest study is the first to show the same technique can be used to partially rewind the clock on cells – enough to make them younger, but without the cells losing their specialised function.
Reik explained: “In iPS cells you reset the ageing clock and go back to zero. Going back to zero, to an embryonic state, is probably not what you want. So you ask: where do you want to go back to?”
The scientists tested the treatment in mice with a genetic disorder, called progeria, which is linked to accelerated ageing, DNA damage, organ dysfunction and dramatically shortened lifespan.
After six weeks of treatment, the mice looked visibly younger, skin and muscle tone improved and lived 30% longer. When the same genes were targeted in cells, DNA damage was reduced and the function of the cellular batteries – mitochondria – improved.
Crucially, the mice did not have an increased cancer risk, suggesting the treatment had successfully rewound cells without turning them all the way back into stem cells, which can proliferate uncontrollably in the body.
The potential for carcinogenic side-effects means the first people to benefit are likely to be those with serious genetic conditions where there is more likely to be a medical justification for experimental treatments.
The approach used in the mice could not be readily applied to humans as it would require embryos to be genetically manipulated, but the team believes the same genes could be targeted with drugs.
“These chemicals could be administered in creams or injections to rejuvenate skin, muscle or bones,” said Izpisua Belmonte. “We think these chemical approaches might be in human clinical trials in the next 10 years.”