A drug currently used to reduce the risk of rejection of transplanted organs appears to reverse the damage caused in DNA by aging.
The discovery, scientists say, could be a potential treatment for children with a rare genetic disease called Hutchinson-Gilford syndrome or progeria, which causes patients to wear out eight times faster than normal.
But it could also have a beneficial impact to slow the normal aging process in humans, says the study published in the journal Science Translational Medicine.
The research was conducted by scientists at the National Human Genome Research, University of Maryland, the Massachusetts General Hospital and Harvard Medical School, United States.
Progeria is an extremely rare and lethal disease that affects about one in 8 million live births.
Patients rarely survive 13 years.
The disease is caused by a new mutation, not inherited, which causes the production of a protein called progerin that can not be processed normally and accumulates in the nucleus of cells.
This accumulation of progerin in cells that are dividing inversely affects the nucleus, causing havoc on cellular function.
Scientists have long studied with interest the disease because they believe that this could be important clues about the normal process of human aging.
Children with progeria often have the same symptoms seen in the elderly, such as stiff joints, hip dislocation and cardiovascular disease.
Scientists know that the progerin protein also occurs in normal cells and this production is increased by high levels, as old age approaches.
The new research involves taking cells from children with progeria who were treated in the laboratory with a drug called sirolimus (also known as rapamycin).
The drug, produced from a substance found in Easter Island, is a powerful immunosuppressant and is used to avoid the risk of organ rejection in patients receiving transplants.
Previous studies with mice had also shown that rapamycin does prolong the life of animals.
Now the researchers compared the effect produced by the drug treated cells and untreated cells.
They found that the drug helps cells get rid of the accumulation of progerin and reverse the defects in the cell nucleus that cause the reduction of longevity.
Involvement in longevity
“When cells of children with the disease were exposed to the drug in the laboratory, they managed to eliminate the abnormal accumulation of progerin and survive longer,” says Dr. Francis Collins, lead author of the study.
“Not only that, the nucleus of cells with progeria went from being ugly and abnormal to extremely beautiful, smiling like a ball,” adds the scientist.
The researchers are planning to conduct clinical trials to test the effects of rapamycin in children with progeria.
The finding, says Dr. Francis Collins, lead author and director of the National Human Genome Research, could also have implications for the understanding of normal human aging.
“Several recent studies report that progerin protein is produced in low amounts in normal individuals but accumulates with age,” says the scientist.
“The rapamycin has been shown to prolong the life expectancy in healthy mice. Therefore, it is possible that the same mechanism that accelerates the elimination of toxic progerin contribute to a beneficial effect of rapamycin on longevity,” he adds.
The study, published in the journal Nature in 2009 showed that mice treated with rapamycin were able to live 38% longer than animals not receiving the drug.