NEW YORK Jun 08 (Reuters Health) -- People with progeria -- a rare, rapid aging disease -- have low levels of the antioxidant enzymes believed to fight aging, researchers from the University of Iowa, Iowa City, have found.
"We're very certain that the loss of these enzymes is damaging," said one of the team, Dr. Larry W. Oberley, a radiology professor, in an interview with Reuters Health.
The results not only suggest that replacement of these enzymes may help treat people with progeria, but they also provide insight into the normal aging process, he said.
"This is an extremely devastating disease," he said. People with progeria live on average to the age of 13. "By the time they're 6 years old, they look like they're 60 or 70."
In addition to rapid aging, patients suffer delayed growth, a build up of fats and cholesterol in the arteries, cardiovascular disease and other illnesses.
Studying progeria also enables researchers to examine the normal aging process. "We think normal cell aging is caused by free radical damage," said Oberley.
In their study, funded by the National Institutes of Health, Oberley and colleagues compared skin cells of progeria patients with those of healthy patients. Normally, healthy cells produce antioxidant enzymes that attack damaging free radicals. Free radicals are produced through normal metabolic processes in the body, or as the result of disease.
The researchers found that in cells from progeria patients, levels of three important antioxidant enzymes were lower than those found in healthy cells. Activity levels of the enzyme catalase were 50% lower than normal, while glutathione peroxidase activity was 70% less. In addition, the investigators note that progeria cells respond less well to the stress of poor nutrition compared with healthy cells.
Although Oberley said it is not clear exactly how lower enzyme levels affect progeria, the study results indicate a potential avenue of treatment.
The results suggest two types of treatment for progeria, he said. For short-term treatment, existing drugs that mimic the missing enzymes can be studied.
A long-term solution is to use genetic engineering to deliver genes coding for the enzymes into the cells of progeria patients. This way, the genes will be able to produce the missing enzymes in the body.
Research in this area is at an early stage, but may be applicable to many diseases including cancer, heart disease, stroke or diabetes, said Oberley.
"There are very few diseases that don't have a free radical component," he said.
Dietary antioxidants in food or vitamin supplements, such as vitamins C and E, are important but have a smaller effect than the antioxidant enzymes produced by the body, he noted.
SOURCE: Biochemical and Biophysical Research Communications 1999;257:163-167.
