August 10, 2008
Turning Back The Biological Clock
Turning back the biological clock in our bodies may no longer be so far fetched according to researchers.
U.S. scientists say they have found the genetic levers to help improve a system vital to cleaning up faulty proteins within our cells.
According a study published in the journal Nature Medicine, the livers of genetically altered older mice worked as well as those in younger animals.
Researchers suggested the findings might one day help people with progressive brain diseases.
These results show it's possible to correct this protein 'logjam' that occurs in our cells as we get older, thereby helping us to enjoy healthier lives well into old age
The researchers, from Yeshiva University in New York, are studying a process that is vital to the proper working of cells.
Proteins, the fundamental chemicals of cells, often have lives, and need to be cleared away and recycled quickly. The body has a process for that, but it becomes less efficient as we age.
This leads to the less efficient function of major organs - the heart, liver and brain. The build-up can contribute to the diseases of old age.
Dr. Ana Maria Cuervo, from Yeshiva, created a mouse with two genetic alterations. When activated, the first boosted the number of specific cell receptors linked to this protein recycling function.
The second allowed the first to be turned on whenever Dr. Cuervo wished simply by modifying the animal's diet.
When the mice were six months old she turned on the receptor gene. That's the point at which age-related decline in the protein-recycling system begins.
At two years old, the liver cells of these mice were vastly more effective at recycling protein compared with normal mice.
When the overall liver function of the very old genetically modified mice was tested, they performed at a comparable level to much younger mice.
Dr. Cuervo said, "These results show it's possible to correct this protein 'logjam' that occurs in our cells as we get older, thereby perhaps helping us to enjoy healthier lives well into old age."
She believes that the abnormal protein deposits in Alzheimer's in particular could be dealt with more effectively. Cuervo plans to test animal models of Alzheimer's and Parkinson's diseases.
A spokesman for the Alzheimer's Society said, "As we age we have an increase in protein misfolding and general faults in protein processing, so the ability to maintain an effective system to clear these would be beneficial."
"However, a direct line to the clearance of defective proteins in the brain is not so clear from this research."
Thomas von Zglinicki, Professor of Cellular Gerontology at Newcastle University, said that the results were "very exciting".
"It's not often you see studies where they have managed to improve function in this way."
He said that it should, in theory, be possible to achieve the same effect across the whole body. "What they seem to have managed is to maintain the mice at this young stage, and both restore and maintain normal activity."
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