Just one month after they were on death's door, a group of decrepit, prematurely aged lab mice are suddenly lively and youthful again, thanks to a new anti-aging treatment that scientists say might one day help take the edge off getting old.

"These mice were equivalent to 80-year-old humans and were about to pass away," researcher Ronald DePinho tells the Wall Street Journal. Yet after the study, he adds, "they were the physiological equivalent of young adults."

These were never ordinary mice, having been genetically engineered to age quickly, DePinho explains, which gave the researchers a chance to fight aging in an accelerated form. "We stacked the deck against us and asked: Is there a point of no return?" If so, they didn't find it — DePinho and his colleagues managed to reverse the mice's age-related brain disease, restored their lost sense of smell, and even regrew their shrunken spleens, testes and brains. The mice began producing new neurons as well as sperm, and went on to have a typical life span, although they didn't live longer than a normal mouse.

The trick was using an estrogen-based drug to switch on a gene that produces telomerase, an enzyme known to safeguard DNA from the ravages of time. Telomerase produces telomeres, which the WSJ compares to plastic tips on the end of shoelaces, protecting DNA at the end of chromosomes and preventing it from being frayed. The researchers gave the mice this drug as a time-release pellet placed under the skin, and within a month the treated mice were the picture of health.

While this could bode well for treating age-related diseases in humans, it's not without risks. Telomerase is also key to cancer growth, since up to 90 percent of all human cancers need certain levels of the enzyme for their tumor cells to divide continuously, and deactivating telomerase is a major goal of current cancer research. But if it can be activated temporarily, under controlled conditions, DePinho thinks it may offer a viable fountain of youth for both mice and men.

(Source: Wall Street Journal

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Die hard: Scientists reverse aging in mice
Anti-aging study suggests a new telomerase drug may one day fight age-related diseases in humans, too.