Scientists show lack of elastic protein is key in sagging skin

Scientists have identified a stretchy protein they say is associated with the ravages of aging and chronic diseases such as emphysema.

The protein, known as fibulin-5, is critical to the development of elastic fibers that stabilize the outside of cell walls, keeping skin tight and lungs and blood vessels pliable.

Two studies into the function of fibulin-5 appear in the Jan. 10 issue of Nature.

In separate experiments, researchers at the University of Texas Southwestern Medical Center in Dallas and the University of California, San Diego specially bred mice that lack fibulin-5.

Without the protein, the mice in both studies survived into adulthood. However, they developed loose skin and abnormal tissues.

Among the diseases they developed was emphysema, in which lung tissues lose elasticity and cannot expand and contract, limiting the amount of oxygen that is transferred to the bloodstream.

Nearly 2 million Americans suffer from emphysema, usually caused by smoking. Tobacco smoke triggers a release of enzymes that attack elastic fibers in the lungs and destroy air sacs.

Scientists are seeking a way to repair or regenerate the elastic fibers to treat diseases, as well as to improve skin tone and turn back the clock on aging.

"We believe that fibulin-5 will be an indispensable ingredient in the recipe," said molecular biologist Tomoyuki Nakamura, lead author of the UCSD study.

Scientists who were not involved in mouse studies said more research is needed to precisely determine fibulin-5's role. They said it is unlikely that fibulin-5 acts alone.