Wednesday, 7 August 2024

Switching off inflammatory protein leads to longer, healthier lifespans in mice

 Scientists at the Medical Research Council Laboratory of Medical Science and Imperial College London have discovered that 'switching off' a protein called IL-11 can significantly increase the healthy lifespan of mice by almost 25%.

The scientists, working with colleagues at Duke-NUS Medical School in Singapore, tested the effects of IL-11 by creating mice that had the gene producing IL-11 (interleukin 11) deleted. This extended the lives of the mice by over 20% on average.

They also treated 75-week-old mice -- equivalent to the age of about 55 years in humans -- with an injection of an anti-IL-11 antibody, a drug which stops the effects of the IL-11 in the body.

The results, published in Nature, were dramatic, with mice given the anti-IL-11 drug from 75 weeks of age until death having their median lifespan extended by 22.4% in males and 25% in females. The mice lived for an average of 155 weeks, compared with 120 weeks in untreated mice.

The 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 Stuart Cook, who was co-corresponding author, from the Medical Research Council Laboratory of Medical Science (MRC LMS), Imperial College London and Duke-NUS Medical School in Singapore, said: "These findings are very exciting. 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."

"Previously proposed life-extending drugs and treatments have either had poor side-effect profiles, or don't work in both sexes, or could extend life, but not healthy life, however this does not appear to be the case for IL-11."

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

The researchers have been investigating IL-11 for many years and in 2018 they were the first to show that IL-11 is a pro-fibrotic and pro-inflammatory protein, overturning years of incorrect characterisation as anti-fibrotic and anti-inflammatory.

Assistant Professor Anissa Widjaja, who was co-corresponding author, from Duke-NUS Medical School, Singapore, said: "This project started back in 2017 when a collaborator of ours sent us some tissue samples for another project. Out of curiosity, I ran some experiments to check for IL-11 levels. From the readings, we could clearly see that the levels of IL-11 increased with age and that's when we got really excited!"

sources-science daily

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