Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Molecule that usually protects infection-fighting cells may cause plaque deposits inside arteries

16.03.2005


A molecule that usually protects the body’s infection-fighting cells might also contribute to fatty buildups that coat arteries and lead to heart disease, UT Southwestern Medical Center researchers have found.



The molecule, called apoptosis inhibitor of macrophage or AIM, inhibits cell death in macrophages, which circulate in the bloodstream and help the body fend off infection and foreign substances. The AIM-protected macrophages go on to encourage buildup of fats on the interior walls of arteries, according to Dr. Toru Miyazaki, senior author of a study that appears in the March issue of the journal Cell Metabolism.

" We found that AIM is highly expressed in certain macrophages and that lack of AIM dramatically decreased early atherosclerotic lesion development in mice," Dr. Miyazaki said. "These results may imply a novel therapeutic application of AIM regulation for prevention of atherosclerosis in the future. Most importantly and attractively for patients, this approach may not need dietary restriction."


Dr. Miyazaki, associate professor in the Center for Immunology and of pathology, and his colleagues first discovered the protective role of AIM six years ago. In the current study, scientists exposed mice lacking AIM to a fatty diet that would normally induce atherosclerosis. After several weeks, researchers found little to no atherosclerotic lesions. Comparatively, in mice that had normal AIM function, there was marked presence of plaque deposits in the arteries following a diet of high-fat food.

"This was dramatic evidence that showed suppressing AIM function translates into prevention of atherosclerosis," Dr. Miyazaki said.

Atherosclerosis, known as "hardening of the arteries," occurs when the inside walls of an artery become thicker and less elastic. This narrows the space for blood flow and can lead to angina and heart attacks in some people. Fatty buildups occur on the inner lining of an artery and gradually thicken into a plaque. As plaque grows, it narrows the artery more and more. When the plaque ruptures, blood clots form that can block the artery entirely.

Low-density lipoprotein is transported inside arteries by macrophages, which engulf the cholesterol through a process called oxidation. Macrophages produce pro-inflammatory substances, which cause a secondary effect, encouraging other cells to accumulate and worsen plaque buildup in arteries.

"The oxidized lipids are cleared out by macrophage cells, but the lipids themselves are very toxic to cells and promote apoptosis (cell death)," Dr. Miyazaki said. "Therefore AIM production is a self-defense mechanism for macrophage cells, but interestingly, is in turn detrimental for the body."

Atherosclerosis is a contributing factor to a number of cardiovascular diseases - the No. 1 cause of death among people in the United States. It is also highly associated with other risk factors such as smoking, obesity and diets high in fat and cholesterol.

UT Southwestern researchers involved in the study included Dr. Satoko Arai, postdoctoral researcher in the Center for Immunology; Angie Bookout, researcher; John Shelton, research scientist in internal medicine; and Dr. David Mangelsdorf, professor of pharmacology and Howard Hughes Medical Institute investigator. The University of California, Los Angeles, also contributed to this study.

The two-year study was funded by the Juvenile Diabetes Research Foundation and the National Institutes of Health.

Katherine Morales | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>