Liver Protein Points to Anti-Obesity Drugs
The LXR protein may tell the body to store up fat
TUESDAY, April 12, 2005 (HealthDay News) -- A liver protein already well known for its role in regulating cholesterol may also help the body pack on unwanted fat, new research suggests.
The finding could lead the way to new anti-obesity drugs, researchers say.
The protein, called liver X receptor (LXR), helps the body maintain a healthy balance between fat storage and the burning of fat, according to investigators at the University of Texas Southwestern Medical Center, Dallas.
LXR's cholesterol-regulating role was already well understood. In its research, the Texas team found that mice genetically engineered to lack LXR couldn't store fat and didn't become obese -- even when fed a diet high in both cholesterol and fat.
However, when these mice were fed only fat, they were able to store fat as usual. This indicates that it's the cholesterol component of a high-fat diet that activates the body's normal fat storage process.
The study suggests a "dual role for LXRs," senior researcher Dr. David Mangelsdorf, professor of pharmacology and biochemistry, said in a prepared statement. Not only do these proteins "sense and limit the accumulation of dietary cholesterol, but their activation by cholesterol is required to initiate a major fat-storing process," he explained.
The findings, which appear in the April issue of the journal Cell Metabolism, suggest that "there is some cholesterol-related signal that the liver sends out that permits fat burning to happen," Mangelsdorf said. "Uncovering that signal is the big mystery we're trying to solve next, which may have therapeutic applications."
The American College of Physicians has more about overweight and obesity.