Also called zombie cells, they stop normal cell division and lose their ability to function, but they don't fully die off. Instead, they hang around wreaking havoc on surrounding tissues.
One of the most promising strategies in the field of health and longevity is to sweep these cells out of the body. The first human trial gives hope we can do exactly that. . .
Reduces Illness and Increases Lifespan
“I’ve never seen a field grow so quickly," says Laura Niedernhofer, Professor of Biochemistry, Molecular Biology, and Biophysics at the University of Minnesota. Scientists’ interest is surging, she explains, because "there is potential here to go to a root cause of aging.”Although senescent cells were first described 60 years ago, their dark nature wasn't discovered until a decade ago.
Their secretions include a cocktail of toxins that poison surrounding healthy cells. Their accumulation in aged tissues damages them, causing chronic inflammation, compromised organ function and the promotion of tumors.
A groundbreaking study in 2011 by a research team at the Mayo Clinic was the first to show that zombie cells drive the aging process. Using mice that were specially engineered to age fast, the researchers discovered that when “zombie” cells were purged, the animals did not develop cataracts, avoided muscle wasting, and retained fat layers in the skin (as opposed to skin becoming brittle, dry and wrinkled, I guess). The mice could even exercise a lot longer on a treadmill.
A follow-up study in 2016 found that pruning senescent cells in middle-aged mice reduced damage to the kidneys and allowed hearts to better cope with stress. The researchers also saw that behavior was more daring and youthful - and the treated mice lived 20% longer than control mice.
More Recent Study Confirms the Finding
Last year the Mayo Clinic led a mouse study to find out the effects of a type of drug called a senolytic that clears away zombie cells. Called DQ, the pharmaceutical combined dasatinib, which is used to treat cancer, with the plant pigment quercetin, a common supplement you can buy at any supplement outlet.The mice lived 36% longer and were also healthier and less frail.
Dr. James Kirkland, who led the research, said, "We once felt that once people are elderly, it’s too late to avoid geriatric syndromes like frailty, loss of independence, decreased muscle strength, and forms of mild cognitive impairment.
"What we are beginning to find is that we have to rethink that. It’s looking like very old mice are able to substantially improve their health span, reduce or delay age-related diseases and increase their survival.”
The results in mice are impressive. But will it work in humans?
Every Patient Improved
In February, Dr. Kirkland's team together with Wake Forest School of Medicine published the first human study of DQ.14 patients with idiopathic pulmonary fibrosis (IPF) -- a progressive, fatal lung disease -- were enlisted as volunteers. All were given DQ three times a week for three weeks.
Although the pilot trial was only designed to test the drug's safety, the researchers saw consistent improvements in the patients' mobility.
When tested for their ability to repeatedly sit and stand, how fast they could walk over four yards, and how far they could walk in six minutes, the researchers found mobility gains of more than 5%, with the six-minute walk distance improving by an average of 23.5 yards.
In the opinion of co-lead investigator Dr. Jamie Justice, "Though small, this pilot study marks a major breakthrough in how we treat age-related diseases such as IPF.
"Here, we've therapeutically targeted a fundamental biological hallmark of aging that is implicated in IPF, and we show early but promising results for the first time in human patients. This small study represents a major paradigm shift in treatment strategy."
Dr. Kirkland was likewise hopeful. "The results were impressive. All 14 got better in their functional ability. This is simply the start of human studies. We don't know what lies ahead and full trials are now ongoing. So at the moment it’s baby steps, but those baby steps are moving quickly.”
- https://www.nytimes.com/2011/11/03/science/senescent-cells-hasten-aging-but-can-be-purged-mouse-study-suggests.html
- https://www.nature.com/news/destroying-worn-out-cells-makes-mice-live-longer-1.19287
- https://www.latimes.com/science/sciencenow/la-sci-sn-anti-aging-cocktail-20180710-story.html
- https://www.sciencedaily.com/releases/2019/01/190107112944.htm
