A drug that could help humans live longer might sound like the stuff of utopian science fiction.
But the recent discovery of a drug that can extend the lifespan of mice by 25 percent has rekindled hopes of finding a real anti-aging cure.
An international team of researchers has discovered that blocking an inflammatory protein called IL-11 helps mice stay healthier for longer as they age.
Scientists caution that while this promising treatment has already been tested in humans for other age-related conditions, it is too early to know whether it is safe in the long term.
Dr Cathy Slack, an expert in ageing biology at the University of Warwick, told Mail Online: “The function of IL-11 in mice and humans is very similar so the possibility that a treatment could work in the same way is exciting.”
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As our bodies age, damaged proteins and chemicals can build up, which the immune system can mistake for infection.
This causes our bodies to overreact to the natural signs of aging, causing inflammation which can have negative effects on our health in the long term.
Inflammation is associated with cancer, fibrosis, and many other diseases that occur with aging.
While testing methods to detect IL-11, researchers from the UK Medical Research Council’s Institute of Medical Sciences (MRC LMS) found that levels of the protein were significantly higher in older mice.
In 2016, it was already discovered that IL-11 plays a role in activating immune cells and fibroblasts that trigger inflammatory responses.
This gave the team their first hint that IL-11 levels may play an important role in producing the adverse effects of aging.
To further test this theory, the scientists inactivated the gene that produces the IL-11 protein in mice and saw if that extended the mice’s lifespan.
They found that mice whose genes had been degraded lived 25% longer than mice whose genes had not been degraded.
In the second experiment, lead researcher Professor Stuart Cook from Duke-National University of Singapore and his team developed antibodies that removed the IL-11 protein from mice that still carried the gene.
Professor Cook injected 37 mice with the antibody, giving them doses every three weeks from the time the mice reached 75 weeks of age (the equivalent of 55 years in humans).
Compared with 38 mice that received no treatment, those that received the IL-11 antibody lived more than 20% longer.
Importantly, the mice didn’t just live longer, they also stayed healthier for longer — a measure known as healthspan.
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Professor Cook said: “Not only did the treated mice have less cancer and showed no common signs of ageing and frailty, they also saw less muscle wasting and improved muscle strength.”
“In other words, the old mice that received anti-IL11 were healthier.”
These results suggest the enticing possibility that IL-11 treatment could be used as an “anti-aging therapy” in humans.
In their paper published in Nature, the researchers wrote: “Our data suggest that anti-IL-11 therapy is a potentially applicable approach to extend healthspan and lifespan in humans.”
Professor Cook added: “Our aim is that one day anti-IL-11 therapies will be used as widely as possible, helping people all over the world live longer, healthier lives.”
However, experts caution that it is not yet clear whether long-term use of IL-11 inhibitors will have adverse effects on human health.
There are currently several other treatments under investigation that may have anti-aging effects, but few that can extend healthspan and lifespan.
For example, the drug rapamycin works by blocking the action of a protein that controls cell growth and destruction.
Although research suggests that it may have anti-aging effects, it also produces a number of side effects that can harm a person’s overall health.
Dr Slack added: “The effects of IL-11 inhibition on mouse lifespan reported in the study are similar to those observed with rapamycin.”
“However, there are concerns that drugs like rapamycin, because they do not target specific cells or tissues in the body, could have detrimental long-term health effects.”
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However, the researchers argue that because LI-11 has no beneficial function, inactivating the protein is unlikely to cause further complications.
“This is something we inherited from fish through evolution, and it has beneficial effects for them,” lead researcher Professor Stuart Cook explains in the video.
“Unfortunately, it’s an evolutionary vestige that causes harm and disease.”
The study claims that IL-11 inhibition “has a reassuring safety profile and is currently in early-stage clinical trials for fibroinflammatory diseases.”
Dr. Slack also noted that antibody treatments could be improved to be more targeted and safer.
But as is often the case in medical research, it may still be too early to know whether the treatment will actually work in humans.
“It’s too early to tell from this study, but the initial results reported in human cells are promising,” Dr. Slacks said.
She added: “Clinical trials on human longevity are nearly impossible. They would take too long and be too expensive.”
“Rather, it is much more likely that trials will be conducted to determine the impact of IL-11 inhibition on health as people age.”
