New Findings about Cholesterol Accumulation in the Arteries
A study by Dr. Gordon Francis and a team of researchers at St. Paul’s Hospital provides new knowledge about the basic mechanism of coronary artery disease development. The researchers discovered that arterial smooth muscle cells present in the plaque of artery walls play a significant role in creating “foam cells” or cholesterol-overloaded cells that cause cholesterol build-up. Until this point, the contribution of smooth muscle cells has not been known.
The researchers studied the origin of foam cells in the coronary arteries of a large number of patients. Experts have long known that when arteries are injured, white blood cells called monocytes are drawn to the plaque on artery walls. These monocytes create foam cells that take up excess cholesterol. Smooth muscle cells were not previously thought to be major contributors of cholesterol build-up. However, the new study shows that at least 50 per cent of the foam cells in coronary artery plaque come from smooth muscle cells, not the monocytes. The researchers believe that this is partly because smooth muscle cells in the plaque have a large reduction in the protein required to export the excess cholesterol, whereas the monocytes in the plaque have large amounts of this protein, even in advanced lesions. The findings from the study will create a major shift in the approach to coronary artery disease and also provide a new target for therapies to help prevent heart attacks and strokes in the first place.
Other researchers included in the study were: Sima Allahverdian, Ali Chehroudi, Bruce McManus and Thomas Abraham.