Featured Research

from universities, journals, and other organizations

'Toggle switch' to burn fat identified

Date:
April 23, 2013
Source:
Universität Bonn
Summary:
For a long time, scientists have dreamt of converting undesirable white fat cells into brown fat cells and thus simply have excess pounds melt away. Researchers have now gotten a step closer to this goal: They decoded a “toggle switch” in mice which can significantly stimulate fat burning.

For a long time, scientists have dreamt of converting undesirable white fat cells into brown fat cells and thus simply have excess pounds melt away. Researchers at the University of Bonn have now gotten a step closer to this goal: They decoded a "toggle switch" in mice which can significantly stimulate fat burning.

The results are now being presented in the journal Nature Communications.

Many people not only in industrialized nations struggle with excess weight -- but all fat is not alike. "Love handles" in particular contain troublesome white fat cells which store excess food. Brown fat cells are the exact opposite: they burn excess energy as the desirable "heaters" of the body. Scientists at the University of Bonn working with Prof. Dr. Alexander Pfeifer, Director of the Institute for Pharmacology and Toxicology, have spent years using animal models to explore how the undesirable white fat can be converted into sought-after brown fat. "In this way, excess pounds may be able to simply be melted away and obesity combated," says Prof. Pfeifer.

A kind of "trigger switch" spurs fat burning

The researchers have now decoded a "microRNA switch" in mice which is important for brown fat cells. Micro-RNAs are located in the genome of cells and very quickly and efficiently regulate gene activity. The researchers studied a specific microRNA: microRNA 155. The gene regulator micro-RNA 155 inhibits a certain transcription factor, that controls brown fat cell function. Surprisingly, Prof. Pfeifer and his team found that the transcription factor also regulates the levels microRNA 155 establishing a tight feed-back loop that works like a toggle switch: When the microRNA is highly expressed brown fat cell differentiation is blocked; conversely, if the transcription factor wins the upper hand, brown fat is produced at an increased level and this in turn boosts fat burning in the body.

In knockout mice, the gene for Micro-RNA 155 was silent

The researchers at Bonn University and their colleagues from the Federal Institute of Drugs and Medical Devices (BfArM) and from the University of Regensburg worked with so-called transgenic and knockout mice in whom the gene for micro-RNA 155 was either increased or silenced. "The mechanism was already set in motion when the micro-RNA 155 was only halved in the mice," reports lead author Yong Chen, graduate student of the NRW International Graduate School BIOTECH-PHARMA. The mice then had significantly more brown fat cells available than did the control gro up -- and had even converted white fat cells into brown fat cells.

Clues to the causes of lipid metabolism diseases

The micro-RNA functions as an antagonist to the brown fat cells. "As long as enough micro-RNA 155 is present, the production of brown fat cells is blocked," says Chen. Only if it falls below a certain proportion does this brake let up; the blueprint for brown fat can be read and implemented by the cell -- the desired fat burners can develop. These findings help scientists better understand the causes of lipid metabolism diseases.

Hope for new therapies against obesity

The scientists at the University of Bonn see in their results a potential starting point for drugs to combat obesity. The researchers have clues to the fact that the results, if anything, can be transferred from mice to humans. Thus, for example, researchers in Leipzig found increased levels of micro-RNA 155 in significantly overweight patients. This corresponds to findings from animal models: A lot of micro-RNA 155 is associated with reduced fat burning. "However, we are still in the basic research stage," says Prof. Pfeifer. The path to suitable drugs is still a long one.


Story Source:

The above story is based on materials provided by Universität Bonn. Note: Materials may be edited for content and length.


Journal Reference:

  1. Yong Chen, Franziska Siegel, Stefanie Kipschull, Bodo Haas, Holger Fröhlich, Gunter Meister, Alexander Pfeifer. miR-155 regulates differentiation of brown and beige adipocytes via a bistable circuit. Nature Communications, 2013; 4: 1769 DOI: 10.1038/ncomms2742

Cite This Page:

Universität Bonn. "'Toggle switch' to burn fat identified." ScienceDaily. ScienceDaily, 23 April 2013. <www.sciencedaily.com/releases/2013/04/130423110742.htm>.
Universität Bonn. (2013, April 23). 'Toggle switch' to burn fat identified. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2013/04/130423110742.htm
Universität Bonn. "'Toggle switch' to burn fat identified." ScienceDaily. www.sciencedaily.com/releases/2013/04/130423110742.htm (accessed April 19, 2014).

Share This



More Health & Medicine News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) — Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) — In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) — A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) — The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins