Softening Hard Hearts

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A large part of heart disease is atherosclerosis, which is a disease of the arteries. The word comes from Greek and literally means paste and hardness.

If you've ever removed steel water pipes from an old home, you've seen the build up of white calcium carbonate nearly filling the pipe. That also happens inside an artery over time – except it's filled with plaque, a hard substance composed of cholesterol, cellular waste products, and fat.

Not only does that restrict blood flow, plaque can break off, blocking smaller arteries or blood vessels. That can cause a heart attack, stroke or embolism.

To keep plaque from expanding, people take drugs such as statins to lower cholesterol, but researchers are working on a more effective approach. They're looking at what's happening in the blood vessel that's causing the plaque to expand.

Low density lipoprotein, or LDL, the so called bad cholesterol, not only contributes to plaque, it causes inflammation in the cells that line the blood vessel which then further expands plaque. So researchers in this study looked at what would happen if they could stop the inflammation.

Their approach was to use a novel cell therapy. They injected mice with a specialized immune cell called a dendritic cell. Not only did this cell therapy reduce inflammation, it slowed plaque growth which then slowed atherosclerosis progression by about seventy percent.

A major advantage of using dendritic cells is they specifically target the inflammation responsible for plaque expansion. Comparatively, cholesterol drugs have a broader effect on the body including some significant side effects.

This therapy, if it works in humans, can lead to more cell-based treatments for the many vascular diseases people suffer today. The next step will be starting human clinical trials.

More Information

Atherosclerosis
This PubMed entry provides a comprehensive look at atherosclerosis which includes causes, risk factors, treatment and some excellent illustrations.
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Immunotherapy with tolerogenic apolipoprotein B-100-loaded dendritic cells attenuates atherosclerosisin hypercholesterolemic mice
A. Hermansson, D.K. Johansson, D.F.J. Ketelhuth et al. This is the original research article in the widely respected journal, Circulation, describing the experiments with dendritic cells in mice. Circulation 2011;123:1083-1091
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Inflammation and cardiovascular disease mechanisms
"Abstract: The traditional view of atherosclerosis as a lipid storage disease crumbles in the face of extensive and growing evidence that inflammation participates centrally in all stages of this disease, from the initial lesion to the end-stage thrombotic complications. Investigators now appreciate that narrowing arteries do not necessarily presage myocardial infarction and that simply treating narrowed blood vessels does not prolong life. Although invasive approaches such as angioplasty and coronary artery bypass will remain necessary in some cases, we now understand that at least some of the cardiovascular benefits attributable to medical treatment and lifestyle modification (diet and physical activity) may result from reductions in inflammatory processes."
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