NEW YORK, NY (May 22, 2014) Researchers have discovered how a gene commonly linked to obesityFTOcontributes to weight gain. The study shows that variations in FTO indirectly affect the function of the primary cilium, a little-understood hair-like appendage on brain and other cells. Specific abnormalities of cilium molecules, in turn, increase body weight, in some instances, by affecting the function of receptors for leptin, a hormone that suppresses appetite. The findings, made in mice, suggest that it might be possible to modify obesity through interventions that alter the function of the cilium, according to scientists at Columbia University Medical Center (CUMC).
"If our findings are confirmed, they could explain how common genetic variants in the gene FTO affect human body weight and lead to obesity," said study leader Rudolph L. Leibel, MD, the Christopher J. Murphy Memorial Professor of Diabetes Research, professor of pediatrics and medicine, and co-director of the Naomi Berrie Diabetes Center at CUMC. "The better we can understand the molecular machinery of obesity, the better we will be able to manipulate these mechanisms and help people lose weight."
The study was published on May 6 in the online edition of Cell Metabolism.
Since 2007, researchers have known that common variants in the fat mass and obesity-associated protein gene, also known as FTO, are strongly associated with increased body weight in adults. But it was not understood how alterations in FTO might contribute to obesity. "Studies have shown that knocking out FTO in mice doesn't necessarily lead to obesity, and not all humans with FTO variants are obese," said Dr. Leibel. "Something else is going on at this location that we were missing."
In experiments with mice, the CUMC team observed that as FTO expression increased or decreased, so did the expression of a nearby gene, RPGRIP1L. RPGRIP1L is known to play a role in regulating the prim
|Contact: Karin Eskenazi|
Columbia University Medical Center