New method would make the most of the balance between the good and bad of free radicals
Gene therapy has been touted as a possible way to cure genetic diseases, but new research suggests that it could also fight the wear and tear that leads to cardiovascular diseases.
An excess of free radicals can cause damage that often contributes to heart disease and atherosclerosis (hardening of the arteries). But some kinds of free radicals also benefit cells by serving as signaling molecules that relay information as part of the cells’ normal operation.
To work within this delicate balance, researchers in
The technique “would be very useful in gene therapy because
you have a more focused expression of what you want. It’s not on when it’s not
needed,” comments Stefan Ryter of Brigham and Women’s Hospital and
“We’ve been proposing HO-1 therapies for years,” Ryter says. “Not just our group, but the whole field.”
In previous research on lab animals, adding a gene that fights the oxidative effects of free radicals alleviated various cardiovascular diseases. But in large studies on people testing whether antioxidants such as vitamin E reduce the chance of heart disease, those taking the antioxidants actually had a slightly higher risk for the disease.
While these results muddy the role of antioxidants for
reducing cardiovascular disease in humans, Steven Steinhubl of The Medicines
Company based in
“It is critical to remember that the lack of benefits seen in clinical trials to date does not disprove the central role of oxidative stress in atherosclerosis,” Steinhubl wrote in the May 22 American Journal of Cardiology. “Most antioxidant therapies that have been tested were not chosen because they were proved to be the best antioxidants, but rather because of their easy availability. An excellent example is vitamin E. ... In some studies, vitamin E has been shown to have some pro-oxidant effects.”
Steinhubl notes that in smaller studies using different antioxidants, patients did see some benefit.