Findings shed light on harmful cholesterol effect

By David Douglas

NEW YORK (Reuters Health) - Cholesterol is known to promote plaque build-up in blood vessels, which raises the risk of heart attack, and other cardiovascular problems. Now, new research suggests that cholesterol does this by reducing the activity of a chemical called transforming growth factor (TGF-beta).

"The finding that cholesterol causes atherosclerosis (plaques) by attenuating TGF-beta responsiveness in...cells could lead to the development of novel and effective therapies for atherosclerosis," senior investigator Dr. Jung San Huang told Reuters Health.

Huang of Saint Louis University School of Medicine and colleagues note that TGF-beta performs a variety of beneficial anti-inflammatory and other functions and that this chemical is believed to protective against the development of atherosclerosis. The new findings appear in the Journal of Cell Science.

In a series of experiments, the researchers found that cholesterol weakened the response of TGF-beta in all cell types studied. Cholesterol also led to the rapid breakdown of the chemical.

Conversely, treatment with "statin" drugs, such as Lipitor or Pravachol, which lowers cholesterol, increased the activity of TGF-beta.

SOURCE: Journal of Cell Science, October 2nd online issue, 2007.