CHICAGO, Dec. 6 (Xinhua) -- Researchers at Washington University School of Medicine in St. Louis have identified a way to prevent fat cells from growing larger, a process that leads to weight gain and obesity.
By activating a pathway in fat cells in mice, the researchers could feed the animals a high-fat diet without making them obese, according to a study published online in the journal eLife on Tuesday.
The researchers focused on the so-called Hedgehog protein pathway that is active in many tissues in the body. They engineered mice with genes that activated the Hedgehog pathway in fat cells.
After eight weeks of eating the high-fat diet, control animals whose Hedgehog pathways had not been activated became obese. But the mice that had been engineered with genes to activate the pathway didn't gain any more weight than did control animals that consumed normal diets.
The Hedgehog pathway prevented obesity by inhibiting the size of the fat cells.
"Fat gain is due mainly to increased fat cell size," said senior investigator Fanxin Long, a professor of orthopedic surgery at Washington University in St. Louis. "Each fat cell grows bigger so that it can hold larger fat droplets. We gain weight mainly because fat cells get bigger, as opposed to having more fat cells."
By stimulating Hedgehog and related proteins in fat cells, the researchers kept the animals' fat cells from collecting and storing fat droplets.
"More importantly, when we did metabolic studies, we found that the animals with the active Hedgehog pathway not only were leaner, they also had lower blood-glucose levels and were more sensitive to insulin," Long said.
"This could lead us to a new therapeutic target for treating obesity," said Long. "What's particularly important is that the animals in our study ate a high-fat diet but didn't gain weight, and in people, too much fat in the diet is a common cause of obesity."
But translating the findings to humans could be tricky, Long holds, and any drugs that activate the Hedgehog pathway would need to be carefully targeted to avoid potential side effects, as certain cancers have been linked to too much Hedgehog activity.
More than one-third of the adult population in the U.S. is obese, and the estimated annual medical costs for obesity exceed 147 billion dollars. People with obesity have an increased risk for stroke, heart attack, diabetes and cancer.