WEDNESDAY, July 29 (HealthDay News) -- Boston scientists have
succeeded in making brown fat out of mouse and human cells, a feat that
takes scientists a step closer to victory in the fight against obesity and
type 2 diabetes.
Brown fat is "good" fat because it burns energy, acting as a furnace,
to help regulate body temperature by generating heat. The more of this fat
you have, the leaner you tend to be.
"Brown fat is necessary for thermogenesis [heat production], to prevent
shivering. It basically burns off calories," explained Dr. Jacob Warman,
chief of endocrinology at The Brooklyn Hospital Center in New York City.
"It's healthy. It keeps your weight down. Thinner people have larger
amounts of brown fat."
White fat, on the other hand, stores calories and contributes to
obesity.
"This could be very important research if it pans out," said Dr. Spyros
Mezitis, an endocrinologist with Lenox Hill Hospital in New York City. "It
could provide a lot of opportunities for new therapeutics. We don't have
any drugs that really work well to control weight gain."
The paper appears online July 29 in the journal Nature.
A 2007 paper, also published in Nature by the same team,
discovered that the protein PRDM16 could transform immature cells into
brown fat.
Earlier this year, three separate groups of scientists on two
continents independently verified that adult humans possess this slimming
form of fat, which was thought only to be present in children and
rodents.
"Several papers found that humans have a lot of brown fat, contrary to
previous reports," said study senior author Dr. Bruce Spiegelman, a
professor of cell biology at Dana-Farber Cancer Institute in Boston.
Now the team reports that PRDM16 has a collaborator, the protein
C/EBP-beta. The two work together to propel various types of cells
(including adult mouse and human skin cells) to morph into brown fat. Once
transplanted into mice, these galvanized cells turned into energy-burning
brown fat.
"We have our hands on a molecule that can turn cells into brown fat,"
Spiegelman said, and the findings could eventually lead to a couple of
different treatment possibilities.
One would be to take cells from an actual patient, "treat" it with the
PRDM16 and C/EBP-beta combination, then inject it back into the patient
with the hope that it would promote the creation of brown fat.
Another possibility would be to create a drug that would make brown
fat. "That's a more conventional route," Spiegelman said.
"A combination of genes [proteins] are playing a role. It's not just
one gene," Mezitis said. "We need to understand the pattern. We know the
individual genes that may play a role, but we don't know the pattern."
More information
The U.S.
Centers for Disease Control and Prevention has more on
obesity.