Factor of youth? Protein that reverses some effects of aging identified

Vinoth Chandar

In a series of papers released yesterday, researchers showed that it's possible to reduce many of the problems with age, including declines in memory and loss of muscle strength, simply by supplying older mice with blood plasma from younger ones. The work even identified a specific protein, GDF11, that mediates many of the effects. The work suggests that some aspects of the aging brain aren't necessarily an internal feature of the neurons that comprise it, but a product of their interactions with their environment—an environment that could potentially be changed.

The work grew out of a rather unusual laboratory technique that creates what are termed "parabionts," genetically matched animals in which patches of skin are surgically fused. Eventually, their circulatory systems mesh, allowing factors from one animal to freely move through the body of the other.

Fresh blood

Assuming you're working with normal, healthy, age-matched mice, you won't see much of a difference. But researchers started experimenting with mice of different ages. In a paper published in 2011, researchers working with these parabionts showed that the blood of the older mice could impose some of the problems with age, including cognitive decline, when circulated through their younger peers. This effect was eventually ascribed in part to immune signaling molecules called chemokines.