A protein that promotes inflammation could be the key to a longer and healthier life. The blockade of the protein called IL-11 in medium-aged mice increased the metabolism, reduced the frailty and extended the lifespan by about 25%.

Although a research team has only tested these health effects on mice, IL-11 and its molecular partners-which also include chemical messenger substances of the immune system called interleukine-also exist in humans. And candidates for medication that block IL-11 are already in human tests against cancer and fibrosis, a state connected to aging, in which scar tissue replaces healthy tissue.

The new results that were reported on July 17th in Nature indicate that these potential treatments could also have an impact on their lifespan, but separate clinical studies are necessary to be safe.

Nevertheless, IL-11S clearly differs from the amount of other proteins and rejuvenation interventions to check the man, many of which were promising in animal models, but have stalled on the way to clinical studies. "There is a real chance here to implement this into clinical therapies," says Cathy Slack, who studies the biology of aging at the University of Warwick, UK. "And the field is somehow stuck."

a random find

researchers have long known that chronic inflammation contribute to aging associated with aging. When the body gets older and damages damaged proteins and other molecules, the immune system often sees it as a sign of a possible infection, says Stuart Cook, a medical researcher who examines IL-11 at Duke-National University of Singapore Medical School. This can trigger inflammatory reactions, cause further damage and contribute to diseases such as cancer and autoimmune diseases.

The role of IL-11 in the promotion of inflammation has also been clear for a long time. But the connection between protein and aging was discovered by chance, as Cook's colleague, the molecular biologist Anissa Widjaja, also at Duke-National University of Singapore Medical School, tested a method for recognizing IL-11. She accidentally included a sample of proteins that came from an old rat, and the test showed that the IL-11 values ​​in this sample were much higher than in rehearsals of younger rats.

The result led to the team on a new path, although it had not previously concentrated on durability. The researchers tested a variety of samples from boys and old mice and found that IL-11 was consistently abundant in older mouse tissue, including skeletal muscles, fat and liver tissue. When they deleted the gene that coded for the IL-11 protein, the animals had improved health margins-they were healthy-they were healthy-and lived 25% longer than mice with normal IL-11 levels.

next steps

The team achieved similar results when it started for 25 weeks to block the protein in mice that were 75 weeks old-such as the equivalent of 55 years for a person. Similar antibodies are tested in human studies against cancer and fibrosis.

The extent of the reaction is similar to what is observed in some studies in mice when treated with rapamycin, a prominent drug in the anti-aging area that is tested for its advantages. But Rapamycin is associated with unwanted side effects, says Cook, who founded a company based in Singapore called Enleofen, which develops medication for fibrosis. "Rapamycin is good for the lifespan, but not for the health range," he says.

The results are impressive and should have further studies, says Dan Winer, who examines the role of the immune system in aging at the Buck Institute for Research on Aging in Novato, California. An important next step would be to test candidates for IL-11 medication on mice with different genetic background and in several laboratories to ensure that the results are reproducible.

In addition, the determination of the effects of anti-il 11 medication candidates on the lifespan for humans could be a challenge. A clinical study that examines the effects on the lifespan would be long and expensive, and the results could be difficult to interpret because many disruptive factors can influence the lifespan.

Instead, says Cook, researchers should perhaps concentrate on a specific state that is associated with aging, such as the loss of muscle mass, which would provide faster results and a more specific result.

"Aging is a hard field," he adds. "But there are many therapeutic approaches and much more biology that needs to be understood."