(Press-News.org) The calorie-burning and heat-generating brown fat found in full-grown humans is actually not quite brown; it's beige. So says a new study reported on July 12th in the journal Cell, a Cell Press publication, in which researchers fully characterize this promising obesity-fighting tissue in both mice and humans for the first time.
The findings could lead to more specific ways to address the epidemic of obesity and diabetes by giving those beige fat cells a boost, the researchers say.
"We've identified a third type of fat cell," said Bruce Spiegelman of Harvard Medical School. "There's white, brown and now there is this third type that is present in most or all human beings."
In fact, brown fat was once thought to exist only in babies, where it serves to keep them warm. More recent imaging data suggested that adults, too, maintain some brown fat.
But Spiegelman's team previously showed that the energy-burning brown fat found amongst energy-storing white fat in adults wasn't exactly the classical brown fat you see in babies. Babies' brown fat arises from muscle, but these adult brown fat cells arise from the "browning" of white fat.
In the new study, Spiegelman's team cloned beige cells taken from the fat tissue of mice to study their activity at the genetic level.
These expression profiles showed that beige cells are genetically somewhere in between white fat and brown fat. At baseline, they have low levels of uncoupling protein 1 (UCP1), a key ingredient for burning energy and generating heat, similar to white fat. But the beige cells also have a remarkable ability to ramp up their UCP1 expression, turning on an energy-burning program that is equivalent to that of classical brown fat.
The team also found that beige cells respond to a hormone known as irisin to turn on the energy-burning program. That's particularly notable because irisin is released from muscle with exercise, and it is responsible for some of the benefits that physical activity brings.
Irisin might just be the long-sought treatment aimed to increase those coveted energy-burning fat cells. In addition to the therapeutic potential, the new findings might also lead to new and better ways to characterize important differences amongst people in the numbers of beige cells they carry, Spiegelman says.
###Wu et al.: "Beige Adipocytes are a Distinct Type of Thermogenic Fat Cell in Mouse and Human."
In adult humans, brown fat is actually beige
2012-07-13
ELSE PRESS RELEASES FROM THIS DATE:
The challenges facing the vulnerable Antarctic
2012-07-13
A century ago, the South Pole was one of Earth's last frontiers, but now the Antarctic is under threat from human activity.
Led by Monash University's Professor Steven Chown, a multidisciplinary team of experts from around the globe has set out the current and future conservation challenges facing the Antarctic in a Policy Forum article published today in Science.
The team analysed the effectiveness of the existing Antarctic Treaty System for protecting the region, one of the world's largest commons, from the threats of climate change and, as technology improves, increasing ...
Solar system ice: Source of Earth's water
2012-07-13
Washington, DC —Scientists have long believed that comets and, or a type of very primitive meteorite called carbonaceous chondrites were the sources of early Earth's volatile elements—which include hydrogen, nitrogen, and carbon—and possibly organic material, too. Understanding where these volatiles came from is crucial for determining the origins of both water and life on the planet. New research led by Carnegie's Conel Alexander focuses on frozen water that was distributed throughout much of the early Solar System, but probably not in the materials that aggregated to ...
Oregon's Paisley Caves as old as Clovis sites -- but not Clovis
2012-07-13
CORVALLIS, Ore. – A new study of Oregon's Paisley Caves confirms that humans used the site as early as 12,450 radiocarbon years ago, and the projectile points they left behind were of the "Western Stemmed" tradition and not Clovis – which suggests parallel technological development of early inhabitants to the Americas.
The study, published this week in the journal Science, could have a major impact on theories of how the Western Hemisphere was populated. The research was funded by multiple organizations, including the National Science Foundation.
Lead author Dennis ...
Dana-Farber study shows newly isolated 'beige fat' cells could help fight obesity
2012-07-13
BOSTON—Scientists at Dana-Farber Cancer Institute have isolated a new type of energy-burning fat cell in adult humans which they say may have therapeutic potential for treating obesity.
Called "beige fat," the cells are found in scattered pea-sized deposits beneath the skin near the collarbone and along the spine in adult humans. Because this type of fat can burn off calories – rather than store them, as "white fat" cells do – beige fat cells might spawn new therapies for obesity and diabetes, according to researchers led by Bruce Spiegelman, PhD, of Dana-Farber.
Spiegelman ...
Discovery opens door to attacking biofilms that cause chronic infections
2012-07-13
A clever new imaging technique discovered at the University of California, Berkeley, reveals a possible plan of attack for many bacterial diseases, such as cholera, lung infections in cystic fibrosis patients and even chronic sinusitis, that form biofilms that make them resistant to antibiotics.
By devising a new fluorescent labeling strategy and employing super-resolution light microscopy, the researchers were able to examine the structure of sticky plaques called bacterial biofilms that make these infections so tenacious. They also identified genetic targets for potential ...
From aflatoxin to sake
2012-07-13
What do beer, dogs and cats, and corn all have in common?
All of them are the end products of the process of domestication. Almost everybody knows that a number of different animals and plants have been bred for qualities that benefit humans. But few people realize that a number of microbes have undergone a similar transformation.
Take brewer's yeast, for example. It is the quintessential ingredient in beer making: genetically altered to convert the sugars in malted barley into alcohol and to produce metabolic byproducts that give beer its unique taste. In fact, dozens ...
Discovery of chemical that affects biological clock offers new way to treat diabetes
2012-07-13
Biologists at UC San Diego have discovered a chemical that offers a completely new and promising direction for the development of drugs to treat metabolic disorders such as type 2 diabetes—a major public health concern in the United States due to the current obesity epidemic.
Their discovery, detailed in a paper published July 13 in an advance online issue of the journal Science, initially came as a surprise because the chemical they isolated does not directly control glucose production in the liver, but instead affects the activity of a key protein that regulates the ...
Obese kids as bright as thinner peers
2012-07-13
Obesity is not to blame for poor educational performance, according to early findings from research funded by the Economic and Social Research Council (ESRC). In a study that combines statistical methods with genetic information, researchers dispel the false idea that being overweight has damaging educational consequences.
Previous studies have shown that children who are heavier are less likely to do well at school. However, Dr Stephanie von Hinke Kessler Scholder from University of York argues it's vital to understand what drives this association. "We sought to test ...
Childhood trauma linked to adult smoking for girls
2012-07-13
Adverse childhood experiences (ACEs) can stay with us for life. New research published in BioMed Central's open access journal Substance Abuse Treatment, Prevention, and Policy explains how these events can be tied up with adult smoking patterns, especially for women, and suggests that treatment and strategies to stop smoking need to take into account the psychological effects of childhood trauma.
ACEs can range from emotional, physical, and sexual abuse to neglect and household dysfunction and affect a large range of people. In one of the largest studies of ACEs survey ...
Leiden researchers achieve highest resolution ever for human protein
2012-07-13
Receptor
The protein in question is the adenosine A2A receptor, the main receptor for caffeine in the human body. This receptor is also linked to Parkinson's disease. The class of around 800 proteins to which the adenosine A2A receptor belongs forms the target for roughly half of all medicines. 'No wonder that researchers across the globe have been trying for decades to find out more about these proteins,' comments IJzerman.
Crystallizing the protein
To find out whether medicines are effective, you need to understand how the receptors in the cell wall work. An important ...