OTTAWA, Sept. 8, 2011 /CNW/ - Researchers at the University of Ottawa Heart Institute (UOHI) have
discovered that an ancient pathway called autophagy also mobilizes and
exports cholesterol from cells.
A team led by Yves Marcel, PhD, Director of the HDL Biology Laboratory,
UOHI, has shown that autophagy, a pathway preserved during evolution,
functions to engulf and digest cholesterol accumulated in artery walls.
This process facilitates the removal of cholesterol and may provide an
entirely new target to reverse atherosclerosis, the main cause of heart
attack and stroke.
Cholesterol accumulates in the walls of arteries leading to
atherosclerosis, also known as narrowing of arteries and which causes
blockages and reduces blood flow to the heart. This often culminates in
heart attacks and strokes.
The autophagy pathway, which means self-digestion, developed early in
single-cell organisms to allow the clearance of accumulated
dysfunctional molecules. "The finding that autophagy also functions to
digest and liberate cholesterol from cells and the fact that we know
this pathway is regulated offers hope for the development of new drugs
that could activate export of cholesterol from the walls of arteries,"
"There is an urgent need to understand how cholesterol accumulation in
arteries can be reversed," said researcher Mireille Ouimet, who was a
major contributor to the study.
Details of the research were published online earlier this summer in the
journal Cell Metabolism (Cell Metab. 2011: 13(6):655-67) and illustrate
how cholesterol buildup itself triggers autophagy, facilitating the
release of cholesterol for transport back to the liver for elimination
from the body. It is possible that some patients with CAD have an
impaired ability to clear arterial cholesterol by the autophagy
pathway, said Marcel.
Marcel's work lends a greater understanding to the underlying
biochemical complexities involving cholesterol. Cholesterol is
important to cell structure. Problems arise when too much cholesterol
is deposited inside the walls of the coronary artery - the origins of
coronary artery disease (CAD). Researchers now are investigating how
this process is involved in the development of atherosclerosis, a step
that could help experts in cardiovascular medicine understand and find
a new way to halt the progression of heart disease.
Marcel's research career has focused on lipoproteins - the biochemical
mechanism to transport cholesterol and fats through the body. In 1997,
he received the highest medal of honour by the Royal Society of Canada
for his contribution to medical science including research related to
pathways for polyunsaturated fatty acids. This was the McLaughlin
Medal, considered one of the country's most prestigious tributes for
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SOURCE OTTAWA HEART INSTITUTE, UNIVERSITY OF OTTAWA
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