Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Softening arteries, protecting the heart

02.11.2012
Softening Arteries, Protecting the Heart: Penn Study Shows Underlying Connection Between "Good" Cholesterol and Collagen in Heart Health

Arterial stiffening has long been considered a major risk factor for cardiovascular disease. Keeping arteries soft and supple might reduce disease risk, but the mechanisms of how arteries stave off hardening has remained elusive.

Researchers from the Perelman School of Medicine, University of Pennsylvania, Wistar Institute, and The Children's Hospital of Philadelphia have discovered that the protein apolipoprotein E (apoE) plays a major role in maintaining arterial softness by suppressing production of the extracellular matrix, a network of connective tissue in the body. Their research appeared in the most recent issue of Cell Reports.

ApoE is a component of several lipoproteins, including HDL, the "good" cholesterol, and is generally believed to forestall atherosclerosis. But several recent major studies have questioned the link between HDL and cardiovascular protection. Meanwhile, other research involving cultured cells has indicated that apoE has effects beyond its role in regulating lipid levels as a component of HDL. The present work suggests that it may be the apoE-containing HDL that confers the main benefit of HDL by promoting arterial softness.

Analyzing genetic datasets of regular mice and mutant mice without apoE, the researchers showed definite differences in gene expression, with the apoE-null mice displaying marked increase in indicators of stiffening – the proteins collagen, fibronectin, and lysyl oxidase in response to stiffening in the aorta, which led to severe atherosclerosis. To attempt to mitigate the atherosclerosis seen in the apoE-null mice, the researchers fed them a high-fat diet and treated them with a lysyl oxidase inhibitor, which softened their arteries.

Despite highly elevated cholesterol, the mice showed a marked improvement in their atherosclerosis. The results suggest that the lack of apoE results in arterial stiffness, and that even with high cholesterol, increasing arterial elasticity by pharmacologic means can greatly reduce atherosclerotic disease.

"HDL can't be looked at as just one compound, because it is a mixture of different molecular components," explains senior author Richard K. Assoian, PhD, professor of Pharmacology. "The component that has these effects on arterial stiffening is a minor part of total HDL." Assoian notes that this could help to reconcile the conflicting clinical evidence regarding the link between HDL and reduced cardiovascular disease. "It might be the apoE HDL fraction that you need to keep high and not worry about the total HDL," he suggests. Because apoE is only about 6 percent of total HDL, "it could go up sky high or not at all, and you probably wouldn’t detect it in these studies that try to raise total HDL."

The possibility of preventing or treating atherosclerosis by promoting arterial elasticity independent of cholesterol could be a boon for the many people unable to tolerate the statin drugs that are the usual treatment.

"Perhaps there are other routes that you could use, independent of cholesterol and statins, that could help keep atherosclerosis at bay," says co-first author Devashish Kothapalli, PhD. "We think controlling stiffening is one of those. We showed in the paper that even when cholesterol is remarkably high, if you soften tissues back to a healthy level, atherosclerosis is inhibited."

Targeting arterial stiffening could also provide added benefit for patients already on statins. "Ultimately we would hope that controlling stiffening could be used in conjunction with a statin for the large percentage of people who are already on statins but need extra help," says co-first author Shu-Lin Liu, PhD.

Although the current study demonstrates how apoE and apoE-containing HDL promote cardiovascular health by maintaining arterial softness, Assoian notes that a practical treatment would likely not target apoE, because it "does a lot of other things that you don’t want to interfere with. So the goal in my mind would be to develop something that is really targeting stiffness but not affecting any of the lipid aspects of atherosclerosis that apoE and HDL control. The lysyl oxidase inhibitor drug we used in this study, BAPN, is good for proof of principle, but not useful on a practical level, because there are too many side effects."

This work was funded by the National Heart Lung and Blood Institute (Grants 66250, 22633, 56083, 093283)

Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $4.3 billion enterprise.

The Perelman School of Medicine is currently ranked #2 in U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $479.3 million awarded in the 2011 fiscal year.

The University of Pennsylvania Health System's patient care facilities include: The Hospital of the University of Pennsylvania -- recognized as one of the nation's top "Honor Roll" hospitals by U.S. News & World Report; Penn Presbyterian Medical Center; and Pennsylvania Hospital — the nation's first hospital, founded in 1751. Penn Medicine also includes additional patient care facilities and services throughout the Philadelphia region.

Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2011, Penn Medicine provided $854 million to benefit our community.

Karen Kreeger | EurekAlert!
Further information:
http://www.uphs.upenn.edu

More articles from Health and Medicine:

nachricht Penn vet research identifies new target for taming Ebola
12.01.2017 | University of Pennsylvania

nachricht The strange double life of Dab2
10.01.2017 | University of Miami Miller School of Medicine

All articles from Health and Medicine >>>

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 >>>