A drug that stops blockages from forming in blood vessels could be a new way to prevent heart attacks and strokes.
“Arteries are living hoses that narrow and enlarge in order to regulate blood flow to organs and muscles,” says William Fay from the University of Missouri School of Medicine and senior author of the study published in Arteriosclerosis, Thrombosis, and Vascular Biology. “Smooth muscle cells in the artery regulate blood flow by constricting and relaxing. However, when chronic inflammation occurs in a blood vessel―typically in response to diabetes, high cholesterol, and cigarette smoking―the smooth muscle cells in the walls of arteries change their behavior.
“They gradually accumulate inside the artery and narrow the blood vessel. In the case of coronary arteries, which supply blood to heart muscle cells, this process produces blockages that can lead to a heart attack.”
Plasminogen activator inhibitor-1, or PAI-1, is a naturally occurring protein within blood vessels that controls cell migration. With diseases such as diabetes and obesity, PAI-1 over-accumulates in blood vessels. This promotes blockage formation.
This process occurs not only in arteries, but also in vein grafts in patients who have undergone coronary artery bypass graft surgery.
Decreased blockages by 50%
Fay’s research team studied PAI-039, also known as tiplaxtinin, an investigational drug not yet used to treat humans. The researchers found that PAI-039 inhibited the migration of cultured human coronary artery smooth muscle cells, and prevented the development of blockages in arteries and bypass grafts in mice.
“We found that PAI-039 decreased blockage formation by about 50 percent, which is a powerful effect in the models we used,” says Fay, who also serves as a research scientist at the Harry S. Truman Memorial Veterans’ Hospital in Columbia, Missouri. “In addition to reducing vascular blockages, inhibiting PAI-1 also produces a blood thinning effect that prevents the blood clots that trigger most heart attacks and strokes.”
Fay hopes that if future studies are successful, PAI-039 or similar drugs could be used to prevent blockages in arteries and bypass grafts.
“I don’t think there will be any one ‘magic pill’ that prevents arterial diseases, especially for those with other high-risk conditions,” Fay says. “However, perhaps someday a PAI-1 inhibitor can be used in combination with other approaches such as proper diet and exercise, aspirin, and cholesterol medications to prevent blood vessel blockages and reduce heart attack and stroke risk.”
The National Institutes of Health and the Department of Veterans Affairs supported the study.
Source: University of Missouri