Clearing Senescent Cells From Mice Leads To Delay In Age-Related Conditions, Scientists Find
Scientists have come just a little bit closer to stopping aging -- even if it is, so far, just in mice.
Reporting in the journal Nature, researchers from the Mayo Clinic have found a way to clear away what are called senescent cells, which are cells that have stopped dividing and build up as people and animals age.
Science News explains why senescent cells are so bad for the body:
When a cell's DNA becomes damaged by things like ultraviolet radiation or toxins, the cell will often enter a senescent state as a precautionary measure against the cancerous growth that can result from such damage. The immune system normally clears dormant cells from tissues. But as an organism ages, its tiring immune system begins to falter in the fight against these cellular zombies. As a consequence, senescent cells begin to accumulate in the older body, gaining strength in numbers.
By clearing out these cells, scientists were able to either stop or delay aging (and the conditions that come with aging, like cataracts and muscle loss) in mice, according to the study.
"There's been a question of whether senescent cells are important, since they're only a small proportion of cells," study researcher Dr. James Kirkland, M.D., Ph.D., who is the head of Mayo's Robert and Arlene Kogod Center on Aging, told Discover magazine. "Our work indicates that a small number of these cells can have a big impact."
Scientists exposed genetically engineered mice to a drug that activates a molecule called caspase 8 that kills senescent cells. Then, they looked at how this lack of senescent cells manifested in terms of delaying or preventing age-related conditions. They found that there was a delay in the mice developing typical age-related conditions like muscle loss, weakness and cataracts, and a slowing down of other age-related disorders later on in life.
According to the researchers, the study shows "that removal of senescent cells can prevent or delay tissue dysfunction and extend healthspan."
Discover magazine reported that this group of Mayo scientists conducted the study operating under the belief that these senescent cells actually acquire harmful functions. However, some scientists instead think that senescent cells don't gain new harmful functions, but rather lose old, important functions.
Recently, scientists from Yale University found that a drug already used to treat high blood pressure in adults and ADHD in kids also seems to work against age-related memory problems in monkeys (equivalent to "senior moments" in adults).
As we get older, the nerve connections in our prefrontal cortexes become weaker, spurring memory problems. In the Yale study, also published in Nature, scientists found that by using the drug guanfacine, they were able to lower levels of a brain chemical called cAMP (cyclic adenosine monophosphate) to strengthen the nerve connections in our brain, thereby reversing the memory loss.
Other researchers around the world are developing technologies to find a possible "cure" for aging, by way of keeping people healthier for a longer period of time. For more on the efforts being made in this field, watch this video: