Subject: progeria/antioxidants
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, such as glutathione, he noted.
SOURCE: Biochemical and Biophysical Research Communications
1999;257:163-167.