Rejuvenating Effect Found In Blood Of Young Mice

A protein found in the blood of young mice awakens muscles and neurons in old rodents.

Albino lab mouse

Wikimedia Commons

When people speak of the regenerative power of "young blood," they usually mean it metaphorically. But a trio of new studies show that compounds in the blood of young mice can rejuvenate older animals in a number of ways--and suggest that same could possibly apply to humans. In some of the studies, blood from young mice flowed into older ones when their circulatory systems were directly connected; in another study, blood from youngsters, as well as a protein called GDF 11, was injected into elder rodents. In all cases, the older mice showed a number of improvements in health, almost as if they had become young again, as National Geographic reported:

The DNA of old muscle stem cells was repaired; muscle fibers and cell structures called mitochondria morphed into healthier, more youthful versions; grip strength improved; and the mice were able to run on treadmills longer than their untreated counterparts. The protein used in the study, called GDF11, was already known to reduce age-related heart enlargement, which is characteristic of heart failure. But [Harvard researchers Amy] Wagers said the new work shows that GDF11 has a similar age-reversal effect on other tissue, in particular the skeletal muscle and brain. "That means that this protein is really acting in somewhat of a coordinating way across tissues," she said , and that drugs could be developed to target a "single common pathway" seen in a variety of age-related dysfunctions, including muscle weakness, neurodegeneration, and heart disease.

The tranfusions also stimulated the growth of neurons in regions of the brain responsible for memory formation and a sense of smell. These mice were better able to distinguish between different odors, and remember how to navigate a maze, reversing declines in these abilities normally seen in the course of again.

But it is reasonable to think this won't be some sort of silver bullet. Here is one important caveat, as noted in the New York Times:

But scientists would need to take care in rejuvenating old body parts. Waking up stem cells might lead to their multiplying uncontrollably. "It is quite possible that it will dramatically increase the incidence of cancer," said Irina M. Conboy, a professor of bioengineering at the University of California, Berkeley. "You have to be careful about overselling it."