Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research mice help scientists understand the complexities of cholesterol

17.03.2006


Scientists at Wake Forest University School of Medicine and colleagues have developed new research mice to help them better understand how the body makes and uses "good" cholesterol to protect against heart attacks and strokes. Their latest findings are reported in the April issue of the Journal of Clinical Investigation.



"Being able to develop drugs to raise levels of good cholesterol depends on knowing more about the how and where the particles are formed," said John S. Parks, Ph.D., from Wake Forest University School of Medicine. "These animals provide the first tools to address these questions."

High-density lipoprotein (HDL) cholesterol is called "good" cholesterol because higher levels are associated with lower risk of heart attacks. Physicians and scientists believe that HDL carries cholesterol away from the blood vessels and to the liver, where it is passed from the body. It may also help remove excess cholesterol from plaque in arteries, slowing the buildup that can lead to heart attacks and strokes.


Parks, a professor of pathology in the Section on Lipid Sciences, is part of a multi-center team that has developed three groups of research mice to investigate the complexities of good cholesterol. These specially developed mice have mutations in a gene (ABCA1) involved in HDL production. The scientists are using them to pinpoint where good cholesterol is produced and how it helps fight plaque buildup. In one group of animals, the ABCA1 gene is selectively deleted in the liver – which means their livers cannot produce HDL. It was through studying these mice that the scientists were able to report in 2005 that the liver is likely the body’s main source of good cholesterol – producing 70 to 80 percent.

Now, in the Journal of Clinical Investigation, they report that the intestines are the other source – producing 20 to 30 percent. This finding came from studying mice with the ABCA1 gene deleted in the intestine. Before these findings, scientists had thought that HDL formation occurred throughout the body – rather than coming from specific organs.

Scientists also know that very small amounts of HDL are produced in macrophages, cells in the blood vessel walls that are involved in the formation of plaques. Through studying the third group of mice – which produces no HDL in the vessel walls – the scientists hope to answer a conundrum about this source of good cholesterol. Previous research indicates that while the levels of HDL produced in the vessels are very small, it may play a large role in keeping the vessels healthy.

Knowing exactly what organs produce good cholesterol – and which sources are most important in fighting vessel disease – will allow drug developers to target specific organs to raise HDL levels. Currently, there are few drugs to raise HDL levels, and people who need to raise their HDL levels are advised to get more exercise.

The group will use the mice to evaluate potential drug therapies. Several drugs have been developed that can stimulate the ABCA1 gene to produce good cholesterol, but they aren’t useable in humans because of negative side effects. The scientists hope to learn more about how the drugs work and how they could be improved.

"The animals can help us determine which pathways are affected by drug therapy, which can eventually be translated to human studies," said Parks. "They are a valuable tool in the quest to find a therapy to raise HDL concentrations and retard the development of heart disease."

Parks’s colleagues on the current research are from the University of British Columbia in Vancouver, Canada, University Medical Center Groningen, The Netherlands, Academic Medical Center, Amsterdam, The Netherlands, State University of New York Downstate Medical Center, and Institut Pasteur de Lille and Faculte de Pharmacie, France.

Karen Richardson | EurekAlert!
Further information:
http://www.wfubmc.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>