'Fat Switch' Makes Muscle Turn to Flab
A protein that helps switch fat cells on and off may aid scientists eventually understand some of the causes of both obesity and the increasing flabbiness that comes with age, reported Fox News.com, quoting researchers.
The protein, which acts as a signal indicating to cells how they should develop, stops cells from becoming fat cells when it is on. When it is off, or produced at low levels, fat cells are born, a team at the University of Michigan reported.
The protein is called Wnt-10b, the researchers reported in the Journal Science.
"Wnt signaling functions as a fat switch," Sarah Ross, a graduate student who led the study, said in a statement.
"When it's on, fat-cell formation is repressed. When it's off, fat is initiated."
Ormond MacDougald, an assistant professor of physiology, who oversaw the work, stressed that the finding is not an answer for the 55 percent of Americans who are overweight and the 18 percent who are obese, or 30 percent over ideal weight.
"It's not the cure for obesity next week," MacDougald said in a telephone interview.
"Obesity is a complicated problem and it's largely controlled by centers in the brain that control our appetite and also control whole body energy metabolism."
But, he said, the study would help scientists understand just how obesity develops, and also adds to the understanding of the signals that tell cells what to do, said the report.
According to the study, all cells start out as stem cells, which are a kind of master cell that have the ability to become any one of a number of kinds of cell.
From there they become precursor cells, which have a more limited number of choices.
Understanding the signals that control these processes is a major goal.
Ross and MacDougald's team worked with fat precursor cells, exposing them to Wnt, which is a cell signaling protein.
"During development, Wnt signaling seems to tell the cells, 'You're supposed to be a fat cell, you're supposed to be a muscle cell,' and so forth," Ross told Science Journal.
"This signaling mechanism helps direct the cell's fate. If that toggle is switched the wrong way, then we see more fat formation."
Muscle precursor cells called myoblasts also turned into fat cells when Wnt was suppressed, they said.
That suggests that the "fat cell" setting is a kind of default, at least for these particular cells, MacDougald said.
One next step would be to see if it is possible to make a fat precursor cell turn into a muscle cell, researchers said - Albawaba.com
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