Researchers at the University of Minnesota have discovered a gene that may provide a clue as to why obesity rates increase with age. The research was published today in the Proceedings of the National Academy of Sciences.
Researchers in the lab of Kevin Wickman, Ph.D., associate professor of pharmacology at the University of Minnesota Medical School, removed a single gene from mice as part of an ongoing study to understand how the brain controls heart function. While some cardiac deficiencies were detected in these mice, the researchers unexpectedly found that these mice exhibited a predisposition to adult-onset obesity.
"This was not an outcome we expected, but now we have an animal model that may provide new insight into human obesity," said Wickman, co-author of the article.
By examining closely where this gene, termed Girk4, is expressed in the body, the researchers found particularly high levels in the hypothalamus, a brain region involved in regulating food intake and energy expenditure. Wickman speculated that disruption of normal function in the hypothalamus may underlie the obesity seen in the mutant mice, but he acknowledges that more research is needed to understand where and how this gene works, and consequently, why mice missing this gene develop obesity.
The age-dependence of the obesity seen in this mouse model mimics human obesity patterns, researchers said. Indeed, the likelihood of people developing obesity more than doubles between the ages of 20 and 60.
"This is a novel finding that may provide important new insight to the underlying cellular mechanisms that influence obesity," said Catherine Kotz, Ph.D., co-author of the article, scientist at the Minneapolis VA Medical Center and adjunct professor in the Department of Food Science and Nutrition at the University of Minnesota.
Source: University of Minnesota
Related stories:
Research team discovers brain pathway responsible for obesity
University of Wisconsin-Madison researchers, for the first time, have found a messaging system in the brain that directly affects food intake and body weight.
Mapping the neuron-behavior link in Rett Syndrome
A link between certain behaviors and the lack of the protein associated with Rett Syndrome – a devastating autism spectrum disorder – demonstrates the importance of MeCP2 (the protein) and reveals never-before recognized functions associated with aggression and obesity, said researchers at Baylor College of Medicine in a report in the current issue of the journal
Neuron.
Key protein molecule linked to diverse human chronic inflammatory diseases
Liwu Li, associate professor of biological sciences at Virginia Tech, has revealed a common connection between the cellular innate immunity network and human chronic inflammatory diseases, including atherosclerosis, Type 2 Diabetes, and neurodegenerative diseases. The finding presents a viable cellular and molecular target for the diagnosis and treatment of serious human inflammatory diseases, according to Li.
New master switch found in the brain that regulates appetite and reproduction
Body weight and fertility have long known to be related to each other – women who are too thin, for example, can have trouble becoming pregnant. Now, a master switch has been found in the brain of mice that controls both, and researchers at the Salk Institute for Biological Studies say it may work the same way in humans.
Low levels of brain chemical may lead to obesity
A brain chemical that plays a role in long term memory also appears to be involved in regulating how much people eat and their likelihood of becoming obese, according to a National Institutes of Health study of a rare genetic condition.
Researchers find a new role for a 'Foxy Old Gene'
Researchers at the University of Pennsylvania School of Medicine have discovered that a protein called FOXA2 controls genes that maintain the proper level of bile in the liver. FOXA2 may become the focus for new therapies to treat diseases that involve the regulation of bile salts. The study was published online this week in
Nature Medicine.
Exercise in a Pill
Trying to reap the health benefits of exercise? Forget treadmills and spin classes, researchers at the Salk Institute for Biological Studies may have found a way around the sweat and pain. They identified two signaling pathways that are activated in response to exercise and converge to dramatically increase endurance.
Resveratrol found to improve health, but not longevity in aging mice on standard diet
Scientists have found that the compound resveratrol slows age-related deterioration and functional decline of mice on a standard diet, but does not increase longevity when started at middle age. This study, conducted and supported in part by the National Institute on Aging (NIA), part of the National Institutes of Health, is a follow-up to 2006 findings that resveratrol improves health and longevity of overweight, aged mice. The report confirms previous results suggesting the compound, found naturally in foods like grapes and nuts, may mimic, in mice, some of the effects of dietary or calorie restriction, the most effective and reproducible way found to date to alleviate age-associated disease in mammals.