School of Medicine

Scientists gave old mice blood of the young and it made them live longer and look younger

Scientists who dosed old mice with an enzyme from the blood of young mice say it extended their lives by 16 percent, as well as making them look younger.

Treating the older mice with an enzyme from the blood of younger mice appeared to slow processes linked to aging, according to the authors of the study published in the journal Cell Metabolism.

The study looked at a molecule called Nicotinamide Adenine Dinucleotide (NAD), which is found in all living cells and plays a role in generating energy. It has previously been shown to decline as we age. An enzyme called extracellular nicotinamide phosphoribosyltransferase, or eNAMPT, is important for creating NAD.

In lab tests on mice, the team found levels of eNAMPT in the fat tissue of mice—from where it is released—dropped by 33 percent at the age of 6 months to 74 percent in the mice. Those with more eNAMPT in their bodies lived longer.

They also tested whether giving older animals the blood component eNAMPT could help slow aging and increase their lifespan by keeping NAD production going.

After being dosed with eNAMPT, the mice seemed to reap benefits across their bodies.

They were better at producing insulin, the cells in their eyes respond to light worked better, their sleep quality improved, and they could run for longer on exercise wheels. When the mice carried out memory tests, their cognitive functions appeared to have become slicker.

The enzyme moves particles called extracellular vesicles around the body. The researchers gave mice aged 26 months extracellular vesicles containing eNAMPT from young to middle-aged mice between 4 to 12 months old. They did this once a week, and found they lived longer compared with mice in the control group mice given a saline solution.

Dr. Shin-ichiro Imai, a professor of developmental biology at Washington University School of Medicine and senior author of the study commented in a statement: “We have found a totally new pathway toward healthy aging.”

“We were surprised by the dramatic differences between the old mice that received the eNAMPT of young mice and old mice that received saline as a control,” he said.

“These are old mice with no special genetic modifications, and when supplemented with eNAMPT, their wheel-running behaviors, sleep patterns and physical appearance — thicker, shinier fur, for example — resemble that of young mice.”

Read more.