New Delhi: Scientists have discovered a potential way to stave off the detrimental effects of aging, according to their research in mice. The study suggests that a protein that is abundant in the blood of young mice plays a vital role in keeping them healthy. With age, levels of this protein decline in mice and people, while health problems such as insulin resistance, weight gain, cognitive decline, and vision loss increase. Supplementing older mice with the protein obtained from younger mice appears to slow this decline in health and extend the life spans of older mice by about 16 percent.
As reported in Cell Metabolism, the circulating protein, an enzyme called eNAMPT, is known to orchestrate a key step in the process cells use to make energy. With age, the body’s cells become less and less efficient at producing this fuel—called NAD—necessary to keep the body healthy. Researchers showed that supplementing eNAMPT in older mice with that of younger mice appears to be one route to boosting NAD fuel production and keeping aging at bay.
“We have found a totally new pathway toward healthy aging,” says senior author Shin-ichiro Imai, a professor of developmental biology at Washington University 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.”
Imai has long studied aging, using mice as stand-ins for people. Unlike other studies focused on transfusing whole blood from young mice to old mice, Imai’s group increased levels of a single blood component, eNAMPT, and showed its far-reaching effects, including improved insulin production, sleep quality, function of photoreceptors in the eye, and cognitive function in performance on memory tests, as well as increased running on a wheel.
The researchers also showed other ways to boost NAD levels in tissues throughout the body. Most notably, the researchers have studied the effects of giving oral doses of a molecule called NMN, the chemical eNAMPT produces. Researchers are testing NMN in human clinical trials.
“We think the body has so many redundant systems to maintain proper NAD levels because it is so important,” Imai says. “Our work and others’ suggest it governs how long we live and how healthy we remain as we age. Since we know that NAD inevitably declines with age, whether in worms, fruit flies, mice, or people, many researchers are interested in finding anti-aging interventions that might maintain NAD levels as we get older.”
-From Our Bureau