UK researchers have discovered that a protein – once thought to  prevent organ damage – is a key driver of ageing, a discovery that may eventually see people living longer and resisting cancer.

The scientists found that ‘switching off’ this protein – called interleukin 11 (IL-11) – increased the healthy lifespan of mice by more than 20 per cent on average.

That was in lab-created mice that had the gene producing IL-11 deleted.

In a separate experiment, an injection of an anti-IL-11 antibody extended the life of ageing mice by 22.4 per cent in males – and 25 per cent in females.

The mice lived for an average of 155 weeks, compared with 120 weeks in untreated mice.

Their coats were glossier, metabolism boosted and they were less frail than untreated middle-aged mice.

In the lab, they were nicknamed “supermodel grannies”.

What about humans?

The big question: Could the drug that slowed ageing in mice work the same way in people?

A new drug – a manufactured antibody that attacks interleukin 11 – is being trialled in patients with lung fibrosis.

The human trial is testing for safety, and early results look promising.

These mice are the same age. The one on the left has aged normally, the one on the right has received an anti-ageing drug.

As for extending longevity, the researchers are cautiously talking up the prospect.

Experiments with human tissues and cells are also encouraging.

Stuart Cook is a professor of cardiac sciences with the Medical Research Council Laboratory of Medical Sciences, Imperial College London and Duke-NUS Medical School in Singapore, the three organisations that did the research. 

Cook is a corresponding author of the paper published in Nature.

“While these findings are only in mice, it raises the tantalising possibility that the drugs could have a similar effect in elderly humans,” Cook said.

“Anti-IL-11 treatments are currently in human clinical trials for other conditions, potentially providing exciting opportunities to study its effects in ageing humans in the future.”

Other benefits

According to a statement from UK Research and Innovation, the drug treatment “largely reduced deaths from cancer in the animals, as well as reducing the many diseases caused by fibrosis, chronic inflammation and poor metabolism, which are hallmarks of ageing”.

There were very few side effects observed.

Professor Cook said: “The treated mice had fewer cancers, and were free from the usual signs of ageing and frailty, but we also saw reduced muscle wasting and improvement in muscle strength. In other words, the old mice receiving anti-IL11 were healthier.”

Cook said that previous attempts to produce life-extending drugs and treatments had poor side effects, or didn’t work in both sexes. When they managed to extend life, it wasn’t heathy life.

“This does not appear to be the case for IL-11,” Cook said.

Science had it wrong about IL-11 for years

Cook and his team have been investigating IL-11 for many years.

In 2017, they were the first to show that IL-11 is a pro-fibrotic and pro-inflammatory protein.

This overturned a prevailing belief that the protein was protective as an anti-fibrotic and anti-inflammatory.

Their research also found that inhibiting IL-11 could prevent the build-up of excess connective tissue in the hearts and kidneys of mice, a process called fibrosis.

What about IL-11 and ageing?

After about the age of 55, our bodies produce more IL-11.

Research has linked the protein to chronic inflammation, fibrosis in organs, disorders of metabolism, muscle wasting, frailty and cardiac fibrosis.

Assistant Professor Anissa Widjaja, who was co-corresponding author, from Duke-NUS Medical School, Singapore, said: “We found these rising levels contribute to negative effects in the body, such as inflammation and preventing organs from healing and regenerating after injury.”

She said although the work was done in mice, “we hope that these findings will be highly relevant to human health”.

The researchers caution that the results in this study were in mice.

The safety and effectiveness of these treatments in humans needs further establishing in clinical trials. Only then could humans consider using anti-IL-11 drugs as an anti-ageing treatment.