Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newly discovered 'platform' for processing dietary fat

05.04.2007
A new "platform" with a crucial role in the body's ability to process and take up fat from the diet has been found, according to a report in the April issue of the journal Cell Metabolism, published by Cell Press.

Researchers discovered a protein that sits on the inner surfaces of capillaries, where it delivers "packages" of dietary fat from the bloodstream to enzymes that prepare them for entry into cells of the body. Once inside cells, the fats are either burned as a rich source of energy or stored for later use.

"We've found a new, very important partner in a process people thought they understood 20 years ago," said Anne Beigneux of the University of California, Los Angeles.

While it is too soon to say whether the finding will have clinical implications—in efforts to limit the body's capacity to store fat, for instance—one thing is for certain: "Soon, every biochemistry book will have to be revised," she said.

Dietary fats in mammals are packaged by the intestine into "chylomicrons," which are large triglyceride-rich lipoproteins, Beigneux explained. After reaching the bloodstream, the triglycerides within chylomicrons are broken down by an enzyme found along the surface of capillaries, mainly in the heart, skeletal muscle, and fat tissue. In those tissues, the so-called lipoprotein lipase enzyme is synthesized, secreted, and transported to the capillaries, where the packaged lipids are taken apart.

The fat "bundles" have to be broken down because the lipids are otherwise unable to get across cell membranes, Beigneux added.

The researchers "stumbled onto" a new player in the process after a team at Genentech found mutant mice with severe chylomicronemia, a condition in which the inability to properly process dietary fat leads to high levels of blood triglycerides.

The mice—which lacked a gene called glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1, or Gpihbp1—exhibited a striking accumulation of chylomicrons in the plasma, even on a low-fat diet, the researchers report. The animals' deficiency caused their blood plasma to become milky as their blood triglyceride levels skyrocketed. Normally, the lipoprotein-binding protein is found at high levels in heart and adipose tissue, the same tissues that express high levels of the enzyme that breaks chylomicrons down, they report.

The researchers conclude that GPIHBP1 is crucial for chylomicron processing. It is located on the inner surface of the capillary and binds both chylomicrons and the processing enzyme, likely forming a platform for lipid breakdown and playing an important role in the delivery of lipid nutrients to cells.

The findings might have direct implications for patients with chylomicronemia, Beigneux said. The disorder in humans has been linked only to defects in the genes encoding the lipid-degrading enzyme or its cofactor, she explained.

"Now, anybody who has chylomicronemia without one of those mutations should be looked at for a mutation in [this platform protein, GPIHBP1]," she said.

Erin Doonan | EurekAlert!
Further information:
http://www.cell.com

Further reports about: Beigneux HDL-cholesterol Triglyceride chylomicron

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

Metallic nanoparticles will help to determine the percentage of volatile compounds

20.10.2017 | Materials Sciences

Shallow soils promote savannas in South America

20.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>