WUSTL researcher studies Methuselah of the mammals

Who would have thought the secret to a long life might exist in the naked, wrinkled body of one of the world’s ugliest animals? Current research may be leading seekers of the Fountain of Youth to a strange little beast — the naked mole rat.

Not one of nature’s cuddliest species, naked mole rats are hairless, wrinkled, blind and buck-toothed. Yet Stanton H. Braude, Ph.D., lecturer in biology in Arts & Sciences, is attracted to these small rodents and has been studying their life span for more than 25 years — 20 of those in Kenya.

Braude is working on a book that will serve as a synthetic review of the past 20 years of research on naked mole rats. While other research has been conducted on naked mole rats in a lab setting, Braude and his students are the only researchers who have studied the creature in the wild.

“I make the case (in my book) that if you really want to understand the lab work, you also have to know what these animals are doing in the wild,” Braude said.

Some of the “hottest” research on naked mole rats concerns senescence, or aging. Naked mole rats in the lab have reached up to 28 years of age. And that’s not the result of the controlled environments of their captivity. Braude has observed mole rats in the wild that are 17 years and older. “For a rodent of this size, they are ridiculously long-lived,” Braude said.

But these are the breeders. Lab researchers didn’t realize that in the wild, worker mole rats live only two or three years.

A key component in the aging of any species is oxidative damage, where cells, as they age, accrue damage from poisons, environmental toxins and other effects. In such a long-lived rodent, it was thought naked mole rats had a very efficient way of repairing oxidative damage. But current theory points to the strange metabolism of this hairless wonder.

Naked mole rats appear to deal with oxidative stress in pulses, largely due to their ability to essentially shut down their metabolism when there are hardships such as a lack of food. In this way, mole rats may be able to rid their body of harmful reducing agents and poisons more easily during these metabolic pulses.

“Another way to think of it — their gross life span might be 28 years, but their metabolism is going in these short bursts, so maybe the net damage is only 3 or 4 years of net use,” Braude said. “They’re living their life in pulses.”

Shelley Buffenstein, Ph.D., of the University of Texas at San Antonio, is one of the researchers leading the way in senescence research and the naked mole rat. She hopes to accompany Braude to Kenya in 2009 to observe mole rats in their natural habitat.

So how are these naked guys going to help us? Parrots and sea turtles also are long-lived, and perhaps one day humans will be able to harness whatever biological process these animals are using as well.

“If we understand how these different species do it, then the next step is to figure out how we can get those benefits with either drug treatments, changing diet or changing lifestyle,” Braude said. “It’s nice that we have a mammal that also is (living long), so there is hope that it’s not just a bird and reptile thing.”

The senescence of naked mole rats is not Braude’s primary concentration. He considers himself a behavioral ecologist and takes his perspectives on physiology and applies it to these animals in the wild. He originally was drawn to these animals, as were many researchers at the time, because of their eusocial behavior. Naked mole rats, like bees and ants, have a queen and workers.

During his time studying naked mole rats in Kenya, Braude observed many traits and behaviors that make this animal unique.

Naked mole rats in nature kidnap pups from other colonies and bring them back to serve as workers in their own tunnels; naked mole rats will invade neighboring colonies and fight for a hostile takeover; and when naked mole rats disperse, or leave the colony to found a new one, they can be found up to two kilometers away.

“They’re blind, they’re hairless, they’re small, but they’re running … two kilometers from where they’re born when it’s time to disperse,” Braude said. “That’s pretty dramatic.”