Researchers from the Mayo Clinic discovered that removing worn-out cells in lab mice extends their lifespan, which could open up the potential for new treatments that combat age-related diseases in humans, according to Nature. The worn-out cells, called senescent cells, accumulate as animals age and release harmful molecules that are linked to diseases such as kidney failure and type 2 diabetes.
"They're zombie cells," said Steven Austad, a biogerontologist from the University of Alabama at Birmingham. "They've outlived their usefulness. They're bad."
After ceasing to divide, these cells typically release inflammatory chemicals that damage their surroundings and accelerate aging, according to Science News.
In order to examine the effects of these cells on aging, the team genetically engineered mice so that these cells would die off with the injection of a drug.
"We think these cells are bad when they accumulate. We remove them and see the consequences," said Darren Baker, co-author of the study. "That's how I try to explain it to my kids."
After numerous genetic modifications and physiological testing, the team was able to perfect the procedure and examine the results in 12-month-old mice, which is roughly equivalent to 40 human years.
Baker and his team found that the experimental group of mice whose senescent cells were killed off over a six-month time period were much healthier than the control group, which consisted of transgenic mice with accumulations of these cells. In particular, the experimental group possessed higher levels of kidney functioning, their hearts were more resistant to stress, they explored their cages more and developed cancers at a later age. To top it off, the elimination of senescent cells extended the lifespans of mice by 20 to 30 percent.
The promising results mirror those of a similar study that Baker conducted with his team of researchers back in 2011 when they found that the same technique effectively slowed down aging in mice that possessed a disorder that accelerated aging, according to New Scientist. However, this new study is the first to show that the technique also works in healthy, normally aging mice.
The findings were published in the Feb. 3 issue of Nature.
