Natural protein curbs obesity in mice

Scientists at Georgetown University were studying the role of the naturally occurring protein FGFBP3 in cancer when they made a surprising discovery: It helps regulate metabolism. And when they boosted levels of FGFBP3 in mouse models of obesity, the animals lost more than a third of their fat—despite their genetic predisposition to eat continuously.

FGFBP3 is among a family of proteins that boost a variety of processes in the body, including cell growth and wound healing. The Georgetown team had been studying FGFBP1 because the BP1 gene is known to be overactive in some cancers, and they were curious about BP3’s role in the disease.

They found that BP3 binds to three proteins that regulate the storage and use of sugars and fats. When more BP3 is available, it enhances carbohydrate and lipid metabolism, making it easier for the body to use them for energy rather than storing them. “It's like having a lot more taxis available in New York City to pick up all the people who need a ride,” said Anton Wellstein, M.D., Ph.D., a professor of oncology and pharmacology at Georgetown Lombardi Comprehensive Cancer Center, in a statement.

During the study, the mice were given eight FGFBP3 doses over the course of 18 days. That was enough to drastically reduce their fat mass, they reported in the journal Scientific Reports.

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Several proteins are being investigated as potential anti-obesity therapies. Last month, a team at Sanford Burnham Prebys Medical Discovery Institute reported that mice with high levels of sarcolipin, a protein found only in muscles, did not accumulate excess fat or develop insulin resistance when fed a high-fat diet.

Scientists led by the University of California, San Diego, discovered that an enzyme called MMP-2 may make people less sensitive to leptin, a hormone that normally prevents overeating. And University of Michigan and Vanderbilt scientists are investigating whether an energy-regulating protein called MC3R could be developed into a drug that might help people keep weight off after they improve their diet and exercise routines.

The Georgetown researchers believe that if further preclinical studies of FGFBP3 confirm their findings, a recombinant version of the human protein could be easily produced for human trials in diseases associated with obesity and related syndromes, such as Type 2 diabetes and fatty liver disease.