New type of damage causing heart disease

University of Canterbury
news release

7 October 2003

Scientists discover new type of damage causing heart disease

Canterbury University researchers in the School of Biological Sciences may have brought scientists a step closer to finding a cure for heart disease.

A team led by senior lecturer in biochemistry Dr Steven Gieseg has discovered a new mechanism for damage caused to the body’s cholesterol-carrying particles (lipoproteins).

The knowledge could help with the development of new drugs that would do a better job than the current ones, by targeting the actual disease process.

Heart disease develops when arteries become blocked by a build-up of cholesterol-filled white blood cells in the artery wall. Dr Gieseg’s team has found that white blood cells can turn the protein part of the lipoproteins (the cholesterol-carrying particles) into protein peroxides. When these peroxides enter cells they cause significant damage and cell death.

“These peroxides have always been thought to be on the lipid (fat) part of the molecule, but our work has shown that at least a third of them are actually on the particle’s proteins,” Dr Gieseg said.

“Like the hydrogen peroxide used to bleach hair, protein peroxides are very reactive and can destroy important antioxidants in the blood such as vitamin C. The presence of protein peroxides in the artery wall is likely to have a major effect on the development of heart disease.”

Dr Gieseg’s team is now investigating how these peroxides affect the growth of cholesterol filled cells in the artery wall. Understanding what dietary or drug treatments affected the stability of the protein peroxides could allow scientists to stop the peroxides triggering cell death, he said. They are also examining a number of ways of measuring the levels of protein damage occurring in the body during the development of heart disease and diabetes.

The research was funded by the New Zealand National Heart Foundation and is reported in the latest issue of the journal Free Radical Research.

Dr Gieseg is a senior lecturer in Biochemistry and has worked on free radical damage to proteins for the last thirteen years.

ENDS

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