Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pathologically Elevated Blood Fat Levels in Obesity: Researchers Discover Molecular Causes

11.02.2009
Scientists at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) have discovered a mechanism in liver metabolism that is responsible for pathologically elevated blood fat levels found in severe metabolic disorders.

Mice suffering from metabolic syndrome or type 2 diabetes produce only small amounts of a molecule called LSR in the liver, as reported by researchers headed by Dr. Stephan Herzig of DKFZ in the specialist journal Diabetes.

As a result, only small amounts of fat are transported from the blood into the liver and blood fat levels rise immensely. Stephan Herzig heads the Research Group "Molecular Metabolic Control" at DKFZ.

People who are severely overweight frequently suffer from a condition called metabolic syndrome. It is associated with pathologically elevated blood pressure, blood lipid (triglycerides) and blood sugar levels. Metabolic syndrome can develop into type 2 diabetes and lead to narrowing of the blood vessels (arteriosclerosis), which, in turn, increases the risk of myocardial infarction. For many years, it was unclear what causes the elevated blood fat levels in this condition.

Dr. Stephan Herzig of the German Cancer Research Center and his team have now shown that lipid transporter LSR (lipolysis-stimulated lipoprotein receptor) appears to be responsible for this. LSR, a molecule found in the bowel and primarily in the liver, is responsible for the uptake of fat from the blood. In overweight mice suffering from type 2 diabetes, the production of LSR in the liver is significantly reduced, as Herzig and his colleagues found out. As a result, only little fat makes its way from the blood into the liver and this makes blood fat levels go up.

By administering leptin, a proteohormone which suppresses hunger, the scientists were able to restore the reduced LSR production in the liver of diabetic mice to normal levels. The overweight mice treated with leptin lost weight dramatically – up to 30 percent of their body weight. At the same time, their livers produced substantially more LSR, and blood fat levels dropped back to normal.

“Thus, we have shown for the first time that the LSR molecule plays a central role in lipid metabolism,” Herzig says. „We were also able to provide evidence that apparently it depends on body weight how much LSR is produced in the liver: being overweight is associated with reduced production.” Hence LSR is a possible target for future treatments of metabolic syndrome and type 2 diabetes. There is a great need for such treatments, since it is estimated that about 300 million people worldwide will suffer from type 2 diabetes as early as next year. “If we were able to increase hepatic LSR production in these patients, this would relieve essential aspects of this disease,” said Herzig. All the more so because increased LSR production in the liver not only reduces blood fat levels but also promotes fat breakdown in the liver.

Cancer patients, too, might benefit from these findings. Many of them suffer from what is called tumor cachexia – a life-threatening loss of weight that is associated with the development of fatty liver. “We have found first evidence suggesting that LSR is overproduced in the livers of these patients so that too much fat accumulates in the liver, while peripheral organs are hardly supplied with fat, or energy,” Herzig says. However, he adds, more research needs to be done.

Narvekar et al. Liver-specific Loss of Lipolysis-Stimulated Lipoprotein Receptor Triggers Systemic Hyperlipidemia in mice. Diabetes. DOI: 10.2337/db08-1184 (Advance publication on the Internet).

The German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) is the largest biomedical research institute in Germany and is a member of the Helmholtz Association of National Research Centers. More than 2,000 staff members, including 850 scientists, are investigating the mechanisms of cancer and are working to identify cancer risk factors. They provide the foundations for developing novel approaches in the prevention, diagnosis, and treatment of cancer. In addition, the staff of the Cancer Information Service (KID) offers information about the widespread disease of cancer for patients, their families, and the general public. The Center is funded by the German Federal Ministry of Education and Research (90%) and the State of Baden-Württemberg (10%).

Dr. Stefanie Seltmann | EurekAlert!
Further information:
http://www.dkfz.de
http://www.helmholtz.de

More articles from Life Sciences:

nachricht Molecular microscopy illuminates molecular motor motion
26.07.2017 | Penn State

nachricht New virus discovered in migratory bird in Rio Grande do Sul, Brazil
26.07.2017 | Fundação de Amparo à Pesquisa do Estado de São Paulo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>