Navigation Links
Atherosclerosis and its Mechanics

Atherosclerosis and the changes associated with it begin at vessel branches and this kind of mechanical stretching begins at those branches which activate// a cellular protein that has been known to damage cells The report is the first to link mechanical forces with structural and biochemical changes in blood vessel cells that could explain why atherosclerotic lesions form preferentially at branches of coronary arteries.

The findings, which are currently available online at the journal's Website, were reported by a team of scientists at the University of California, San Diego as part of an ongoing effort to understand how mechanical forces affect the health of cells that line arteries

The cellular protein in question is called JNK, which is short for c-jun N-terminal kinase. The protein is a key barometer of outside stresses on a variety of cell types. Researchers are examining the role of JNK in many diseases because it regulates the expression of genes involved in programmed cell death, tumor genesis, and other stress responses.

Atherosclerosis, the collection of deposits such as cholesterol along artery walls, accounts for nearly 75 percent of deaths from cardiovascular disease. Most drugs to treat atherosclerosis influence the levels of cholesterol and other lipids in the blood, but the UCSD researchers suspect that understanding the role of mechanical forces acting on blood vessel cells may help to design better approaches to treatment.

"We've known for decades that atherosclerotic lesions develop preferentially at vessel branches rather than along unbranched vessels, but we've not been able to identify the biochemical events that trigger formation of the lesions," said Shu Chien, director of the Whitaker Institute of Biomedical Engineering at UCSD. "We now have identified a possible smoking gun: activation of JNK, which is dependent on the directionality of blood vessel stretching."

Chien, res earch scientist Shunichi Usami, and post-doctoral fellow Roland Kaunas, now an assistant professor of biomedical engineering at Texas A&M University, isolated endothelial cells from the bovine aorta and grew them in culture flasks. They seeded the cells onto silicone rubber membranes that had been coated with a protein that allowed the cells to attach the way they do to underlying blood vessel tissue in the body. They then stretched the cells 10 percent of their length 60 times per minute to simulate the rhythmic flexing of an artery in response to heart beats.

Cells that were stretched back and forth along one axis exhibited a healthy response: the level of JNK rose and quickly returned to basal levels as the cells also produced intracellular actin fibers that were aligned perpendicular to the axis of stretching. However, when the researchers stretched cells in two directions simultaneously, they noted an unhealthy response: actin fibers oriented randomly and JNK concentrations rose to higher levels and remain elevated.

"We're continually amazed at how quickly these cells can reorient these stress fibers when we change the direction of stretch," said Chien. "At the same time, the actin cytoskeleton of endothelial cells is somehow playing a key role in activating and deactivating JNK."

The tubular geometry of the straight part of arteries ensures that the cyclical rise and fall of blood pressure results in uniaxial stretch of arteries. However, the more complex geometry of artery branches promotes an unhealthy stretching of the blood vessel along more than one axis.

A second mechanical force, the so-called shear force of blood flowing through vessels, also influences the orientation of stress fibers in endothelial cells. A laminar flow of blood prompts stress fibers to orient in the healthy direction, while disturbed and low blood flows caused stress fibers to form in an unhealthy, random orientation. Chien's group i s now working to understand how both stretching and shear forces influence JNK activation.

"We still need to limit the amount of cholesterol in our diet, especially the low-density lipoprotein, or bad cholesterol," said Chien. "But our new understanding of how mechanical forces affect JNK will eventually help us gain better understanding of the mechanism underlying the focal localization of atherosclerotic lesions and design better approaches to treat this important disease state."

(Eurekalert)
'"/>




Related medicine news :

1. Increase Cereal Fibre To Combat Atherosclerosis
2. Link Established Between Atherosclerosis and Air Pollution
3. Vegetarian Diet Prevents the Development of Atherosclerosis
4. Mothers Healthy Diet Protects Baby from Developing Atherosclerosis
5. Reducing the Risk of Protease Inhibitor-Related Atherosclerosis
6. Anti Atherosclerosis Therapies Linked to Leukemia
7. Early Onset of Atherosclerosis Reported in Obese Children
8. Cholesterol-lowering Drug Effective at Halting Early Atherosclerosis
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/25/2016)... ... 2016 , ... The temporary closing of Bruton Memorial Library on June 21 due to a ... new, often overlooked aspect of head lice: the parasite’s ability to live away from a ... occurrence, but a necessary one in the event that lice have simply gotten out of ...
(Date:6/25/2016)... ... 25, 2016 , ... Dr. Calvin Johnson has dedicated his ... implemented orthobiologic procedures as a method for treating his patients. The procedure is ... to perform the treatment. Orthobiologics are substances that orthopaedic surgeons use to help ...
(Date:6/24/2016)... ... June 24, 2016 , ... Those who have experienced traumatic events ... turn to unhealthy avenues, such as drug or alcohol abuse, as a coping mechanism. ... tools for healthy coping following a traumatic event. , Trauma sufferers tend to feel ...
(Date:6/24/2016)... MIAMI, Fla. (PRWEB) , ... June 24, 2016 , ... ... Florida Trend magazine’s 2016 Legal Elite. The attorneys chosen by their peers for this ... of Florida. , Seven Greenberg Traurig Shareholders received special honors as members of this ...
(Date:6/24/2016)... Plano, TX (PRWEB) , ... June 24, 2016 , ... ... taking part in Genome magazine’s Code Talker Award, an essay contest in which patients ... for an award to be presented at the 2016 National Society of Genetic Counselors ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... 24, 2016   Bay Area Lyme Foundation ... Dean Center for Tick Borne Illness , Harvard ... MIT Hacking Medicine, University of California, Berkeley, and ... the five finalists of Lyme Innovation , ... than 100 scientists, clinicians, researchers, entrepreneurs, and investors ...
(Date:6/24/2016)... ALEXANDRIA, Va. , June 24, 2016 ... a set of recommendations that would allow ... information (HCEI) with entities that make formulary and coverage ... determine the "value" of new medicines. The ... that does not appear on the drug label, a ...
(Date:6/24/2016)... Research and Markets has announced the addition of the ... to their offering. ... World Market for Companion Diagnostics covers the world market for ... report includes the following: , World IVD ... (N. America, EU, ROW), 2015-2020 , World IVD Companion ...
Breaking Medicine Technology: