The breakthrough could lead to improved treatments for a wide variety of ailments, from emphysema and heart disease to wrinkles.
"This is the most exciting new information in this area in a long time. The relevance is just potentially huge," says Lynn Sakai, a biochemistry professor at Oregon Health Sciences University and a leading expert in the field.Led by professors at the University of California at San Diego and the University of Texas Southwestern Medical Center in Dallas, the two teams reached their findings separately. The results appear in tomorrow's issue of the journal Nature.
Scientists have long known that many body organs are made up of elastic fibers that let them expand and shrink.
"It's critical for organs to maintain their shape, because there is stress and strain put on every organ system," says Dr. Kenneth Chien, a professor of medicine at UC-San Diego and senior author of its study.
Blood vessels, for example, must become larger and smaller as blood pressure changes, much like a garden hose that is turned off and on.
Skin works the same way. "If you pinch your skin, it will go back," Chien says. "But as you get older, that elasticity is lost."
Without elasticity, skin starts to sag and wrinkle. The effects are even more serious inside the body. Arteries can become stiff, much like an old, dried-up hose.
Some diseases can reduce elasticity, too. In emphysema, the lung loses its ability to contract. "When you breathe in, there's no intrinsic elasticity to help the lung restore itself to its normal size," Chien says.
While scientists have studied elasticity for some time, it "has been sort of slow to give up its secrets," says Scott Argraves, a biology professor at the Medical University of South Carolina.
That may be changing. Researchers at UC-San Diego suspected a protein called fibulin-5 had something to do with heart disease, so they genetically engineered mice to be born without the gene that creates the protein. They then watched the mice to see how they would be different from normal mice.
The researchers suspected the mice might have a heart problem, Chien says. The animals did -- their non-elastic arteries looked like corkscrews -- but they also had sagging skin, he says. That was a surprise, revealing that the protein is essential in some way to the entire body's elasticity.
The next step is to determine if treatment with the protein could help the body heal itself after elasticity is lost, Chien says. Tests will first be done on animals.
"This is not a cure" for diseases like emphysema, Chien cautions. "It's a new step, and points out a new direction."
Chien prefers to talk about possibilities for treating diseases like Marfan syndrome, which weakens the connective tissues of its sufferers and can cause serious heart problems.
But the protein could be used for a more cosmetic purpose: to make wrinkles and sagging skin disappear, says Sakai of Oregon Health Sciences University.
Many believe wrinkles "are due to loss of a number of different connective tissue proteins that are present in the skin," she says. Other factors, such as sun damage, also play a role.
Another potential use is more serious. Sakai says the elastic protein could eventually be used to treat prolapse, a very common disorder among women in which the bladder, bowel and uterus slip lower in the body. The causes are "completely unknown," she says, but they could have something to do with loss of elasticity.
What To Do
Several diseases are linked to a lack of elasticity, including Marfan syndrome, which may have affected President Abraham Lincoln. Read about it in this primer from the Cold Spring Harbor Laboratory.
You're not the only one with sagging skin and wrinkles who could be helped by future research into elasticity. Learn about the dermatological problems facing celebrities at the tongue-in-cheek, but educational, Skinema.com.