Scientists may have just discovered the secret to anti-aging in a protein in the blood that significantly prolongs the lives of mice.
Extending The Lifespan
In new research, scientists explain that there is a circulating protein in the blood of mice that's crucial in keeping them healthy. It's an enzyme known as eNAMPT and it plays a key role in the cell production of a fuel called NAD, which the body needs to remain healthy.
However, the levels of eNAMPT decline with age as both mice and humans. Consequently, the body doesn't get enough NAD and health problems eventually surface, such as weight gain, insulin resistance, and cognitive decline, among others.
Findings published in the journal Cell Metabolism reveal that giving older mice protein obtained from young mice appears to slow down these health issues that come with age. Experiments showed that receiving this "anti-aging" protein extended the lifespan of these older mice by around 16 percent.
"We have found a totally new pathway toward healthy aging," said senior author Shin-ichiro Imai, MD, Ph.D., a professor of developmental biology at the Washington University School of Medicine in St. Louis. "That we can take eNAMPT from the blood of young mice and give it to older mice and see that the older mice show marked improvements in health-including increased physical activity and better sleep-is remarkable."
Previous studies have tried transfusing whole blood from young mice to old mice. Instead of doing the same, Imai's team opted to increase the levels of the blood component eNAMPT and found that it improves insulin production, sleep quality, photoreceptors function in the eye, cognitive function in memory tests, and increased running on a wheel.
Mice that received a saline solution died before 881 days, which is about 2.4 years. On the other hand, one of the mice that received eNAMPT is still alive at 1,029 days or 2.8 years and counting.
More About eNAMPT
The group also discovered new ways to boost NAD levels in the body's tissues, including giving the mice oral doses of the NMN molecule. This molecule is produced by eNAMPT and is already being tested in human clinical trials.
"We think the body has so many redundant systems to maintain proper NAD levels because it is so important," Imai said, adding that their findings suggest that NAD determines how animals-including humans-age and how long they live. Thus, researchers believe that effective anti-aging interventions may involve maintaining NAD levels while aging.
Imai's research showed that the hypothalamus controls is a major control center for aging, directed greatly by eNAMPT released into the blood from fat tissue. As the levels of eNAMPT decline, the hypothalamus's ability to function properly also decreases and life span drops.
"We could predict, with surprising accuracy, how long mice would live based on their levels of circulating eNAMPT," Imai explained. "We don't know yet if this association is present in people, but it does suggest that eNAMPT levels should be studied further to see if it could be used as a potential biomarker of aging."