James Kirkland began his career as a geriatrician in 1982, treating geriatric patients. But he was frustrated with what he could offer them.
“I was tired of having to prescribe wheelchairs, walkers, and incontinence devices,” recalls Kirkland, now at the Mayo Clinic in Rochester, Minnesota. He knew that aging was considered the greatest risk factor for chronic disease, but was frustrated at not being able to do anything about it. and obtained a doctorate in biochemistry from the University of Toronto. Today, he and his colleague Tamara Ciconia, a molecular biologist at the Mayo Clinic, are leaders in the movement to stem chronic disease by protecting the brain and body from the biological effects of aging. increase.
If these researchers succeed, there will be no shortage of customers. People are living longer, and the number of Americans over the age of 65 is expected to double to 80 million by 2040. By extending life expectancy, we hope to extend the “healthy life expectancy” that allows people to live without getting sick.
One of their targets is aging cells that accumulate in tissues as we age. These “senescent” cells, due to injury, stress, or just time, have reached a point where they stop dividing, but do not die. However, one study showed that it makes up up to 36% of the cells in some organs in aged mice. And it’s not just sitting quietly. Senescent cells can release numerous compounds that create a toxic and inflamed environment that prepares tissues for chronic disease. Senescent cells are associated with diabetes, stroke, osteoporosis, and several other aging conditions.
These harmful cells are gaining serious attention, along with the idea that getting rid of them can reduce the discomfort caused by chronic disease and aging. million dollars invested. It aims to identify and map senescent cells in the human body and mice over their natural life span. Also, the National Institute on Aging has provided more than $3 million over four years to a multi-center team in the Translational Geroscience Network led by Kirkland, which is conducting preliminary clinical trials of potential anti-aging treatments. did. Drugs that kill senescent cells (called senolytics) are among the frontrunners. These small trials are already underway in people with conditions such as Alzheimer’s disease, osteoarthritis and kidney disease.
John Varga, who is not affiliated with TGN but is the Chief of the Department of Rheumatology at the University of Michigan Medical School, Ann Arbor, said:
But he and others have cautioned as well, and some scientists believe the potential in this area has been overstated. . “I have a very healthy dose of skepticism.”
Researchers continue to unravel the biology of senescent cells, not only in aged animals, but also in young animals. So far, the evidence that destroying senescent cells helps extend healthy lifespan has come mainly from laboratory mice. With only a few preliminary human trials completed, there are promising hints, but far from blockbuster results.
Still, Kirkland and Tchkonia speculate that senolytics may eventually help not only with aging, but also with conditions young people suffer from due to injuries and treatments such as chemotherapy. Applications can be everywhere,” thinks Kirkland.
