Washington, July 19 (ANI): Mice gain weight even when fed normal amounts of food, a discovery that suggests the genetic mutation linked to obesity may govern how the body uses energy.
Researchers at Boston Children's Hospital involved genetic surveys of several groups of obese humans and experiments in mice.
Mice with the genetic mutation gained weight even while eating the same amount of food as their normal counterparts; the affected gene, Mrap2, has a human counterpart (MRAP2) and appears to be involved in regulating metabolism and food consumption.
"These mice aren't burning the fat, they're somehow holding onto it," study's lead investigator Joseph Majzoub, MD, chief of endocrinology at Boston Children's, said.
"Mice with the genetic mutation gained more weight, and we found similar mutations in a cohort of obese humans," he said.
The protein created by the Mrap2 gene appears to facilitate signaling to a receptor in the brain called Mc4r, which helps increase metabolism and decrease appetite as part of a larger signaling chain involved in energy regulation.
Fat cells produce the hormone leptin, prompting receptors in the brain to instigate production of a second hormone, aMSH.
Mc4r detects this hormone with the aid of Mrap2, leading to a decrease in appetite and weight.
Mutations in this signaling chain, including mutations in Mc4r, are known to increase the likelihood of obesity.
The study is published in the journal Science. (ANI)