BOSTON--A surprise discovery -- that calorie-burning brown fat can be produced experimentally from muscle precursor cells in mice -- raises the prospect of new ways to fight obesity and overweight, say scientists from Dana-Farber Cancer Institute.
Reporting in the Aug. 21 issue of the journal Nature, the researchers demonstrated that brown fat, which is known as the "good" form of fat -- so called because it burns calories and releases energy, unlike "bad" white fat that simply stores extra calories -- can be generated from unspecialized precursors that routinely spawn skeletal muscle.
The team led by Dana-Farber's Bruce Spiegelman, PhD, 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 laboratory, 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, the senior author of the paper. The lead author is Patrick Seale, PhD, a postdoctoral fellow in the Spiegelman lab.
|Contact: Bill Schaller|
Dana-Farber Cancer Institute