August 20, 2008

Bone Growth Protein Also Promotes 'Good' Fat

WEDNESDAY, Aug. 20 (HealthDay News) -- A protein that induces bone growth also helps promote development of "good" brown fat that helps burn calories and plays a role in fighting obesity, says researchers at the Joslin Diabetes Center in Boston.

They said their finding about the protein, called BMP-7, may help lead to new ways to prevent and treat obesity.

The two main types of fat cells in the body are white and brown, explained study author Yu-Hua Tseng, an assistant investigator in Joslin's Section on Obesity and Hormone Action.

"White fat cells are the 'conventional' form of fat designed to store energy. By contrast, the main role of brown fat is to burn calories by generating heat. Brown fat cells largely disappear by adulthood in humans, but their precursors still remain the body," Tseng said in a Joslin news release.

In laboratory studies of mouse cells, Tseng and colleagues found that BMP-7 drives the precursor cells that give rise to mature brown fat cells. They also found that injecting BMP-7-treated progenitor cells (similar to stem cells) into mice led to increased development of brown fat tissue, and that mice that developed brown fat gained less weight than those that didn't develop brown fat.

The study was published in the Aug. 21 issue of Nature.

The Joslin team hopes this type of research into fat development will lead to new drugs or other treatments for obesity.

"Diet and exercise are still the best approaches for weight reduction in the general population. However, for people who are genetically predisposed to obesity, these approaches may have very little effect," Tseng said.

"As we learn more about the controls of brown fat development, medical interventions to increase energy expenditure by brown fat inducing agents, such as BMP-7, may provide hope to these individuals in losing weight and preventing the metabolic disorders associated with obesity," she said.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about adult obesity.

-- Robert Preidt
SOURCE: Joslin Diabetes Center, news release, Aug. 20, 2008
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