Juan Carlos Izpisúa Belmonte, a professor at the Salk Institute in San Diego, is working on a controversial experimental technique that appears to reverse the effects of old age – albeit so far only in mice. In his experiments, animals are bred to have a condition where they age prematurely.
Just days away from death, the mice are given his ‘elixir’ and soon start to appear younger: more active, with healthier organs, thicker fur and fewer wrinkles.
But there’s a catch: Belmonte’s technique involves stripping away key molecular tags on the DNA in the mice’s cells. This technique, known as epigenetic reprogramming, is like wiping cells ‘back to factory settings’ – which inevitably has huge complications if done throughout an entire organism.
As a result, many of Belmonte’s test subjects, although appearing rejuvenated at first, quickly developed tumours and died. Finding a balance between therapies with an anti-ageing effect and ones that lead to tumours has proven precarious.
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Belmonte’s work may be at an early stage, but he is just one of many scientists who sees ageing as a molecular process in our cells that could soon be adjusted, stopped, or reversed. A gradual failing of complex cellular maintenance systems is what causes cells and tissues to get worn out and stop functioning as we get older, and many research groups claim to have found the genetic ‘switch’ that can reset these problems.
“Cellular ageing is, in my opinion, due to accumulated cellular stresses over a lifetime,” says Dr Lorna Harries, a professor of molecular genetics at Exeter Medical School. “There are ‘master control points’ that regulate molecular stress response that could be targeted.”
Harries and her team recently found two mitochondrial genes that, when inactivated, appeared to reverse various signs of ageing in human cells grown in a lab. “So in one sense, that might be viewed as a ‘switch’, but the consequences of switching that switch are very complicated and we are still working them out. Nothing in biology is ever simple.”
The idea of stopping or reversing ageing is truly radical – it would likely have enormous and frightening implications for the world’s population, for a start. However, most researchers working in this field have a simpler goal – not to keep us
young forever, but to keep people healthier for longer as we age.
Rather than an ‘elixir of youth’, it’s likely that the first therapies will reverse ageing in specific tissues, such as joints or the retina.