Researchers stumble on calorie burning ‘good’ fat !August 21st, 2008 - 3:18 pm ICT by IANS
New York, Aug 21 (IANS) Weight watchers and the obese can take cheer from the surprise discovery of a calorie-burning brown fat that can be produced experimentally from muscle precursor cells in mice.Researchers demonstrated that brown fat, known as “good” fat — because it burns calories and releases energy, unlike “bad” white fat that hoards them — can be generated from unspecialised precursors that routinely spawn skeletal muscle.
The team, led by Dana-Farber Cancer Institute’s Bruce Spiegelman, showed that a previously known molecular switch, PRDM16, regulates the creation of brown fat from immature muscle cells.
They also determined that the process is a two-way street: Knocking out PRDM16 in brown fat cells can convert them into muscle cells. However, Spiegelman called the latter an “experimental lab trick” for which he currently envisions no practical applications.
The “huge surprise” of the study results, he said, was that muscle precursor cells known as “satellite cells” are able to give birth to brown fat cells under the control of PRDM16.
Spiegelman said the finding confirms that PRDM16 is the “master regulator” of brown fat development. The confirmation will spur ongoing research in his lab, he said, to see if drugs that rev up PRDM16 in mice — and potentially, in people — could convert white fat into brown fat and thereby treat obesity.
Another strategy, he said, might be to transplant brown fat cells into an overweight person to turn on the calorie-burning process.
“I think we now have very convincing evidence that PRDM16 can turn cells into brown fat cells, with the possibility of combating obesity,” said Spiegelman, co-author of the paper.
Another paper in Nature also described a different trigger of brown fat production, a molecule called BMP7. A write-up by Barbara Cannon, working at the University of Stockholm, said that the two reports “take us a step closer to the ultimate goal of promoting the brown fat lineage as a potential way of counteracting obesity.”
These findings were reported in the Thursday issue of Nature.