`Scientists discover the longevity gene`

Washington: A genetic `switch` that can reverse the ageing process has been discovered and scientists say the breakthrough could lead to drugs that halt or slow ageing.

A new study led by researchers at the University of California, Berkeley, represents a major advance in the understanding of the molecular mechanisms behind ageing while providing new hope for the development of targeted treatments for age-related degenerative diseases.

Researchers were able to turn back the molecular clock by infusing the blood stem cells of old mice with a longevity gene and rejuvenating the aged stem cells` regenerative potential, according to study published in the journal Cell.

They found that SIRT3, one among a class of proteins known as sirtuins, plays an important role in helping aged blood stem cells cope with stress.

When they infused the blood stem cells of old mice with SIRT3, the treatment boosted the formation of new blood cells, evidence of a reversal in the age-related decline in the old stem cells` function.

"We already know that sirtuins regulate ageing, but our study is really the first one demonstrating that sirtuins can reverse ageing-associated degeneration, and I think that`s very exciting," said study principal investigator Danica Chen.

"This opens the door to potential treatments for age-related degenerative diseases," Chen said in a statement.

Chen noted that instead of an uncontrolled, random process, ageing is now considered highly regulated as development, opening it up to possible manipulation.

"Studies have already shown that even a single gene mutation can lead to lifespan extension.

"The question is whether we can understand the process well enough so that we can actually develop a molecular fountain of youth. Can we actually reverse ageing? This is something we`re hoping to understand and accomplish," said Chen.

Chen worked with David Scadden, director of the Center for Regenerative Medicine at Massachusetts General Hospital and co-director of the Harvard Stem Cell Institute.
Sirtuins have taken the spotlight in this quest as the importance of this family of proteins to the ageing process becomes increasingly clear.

Researchers studied the function of adult stem cells. The adult stem cells are responsible for maintaining and repairing tissue, a function that breaks down with age.

The SIRT3-deficient mice had significantly fewer blood stem cells and decreased ability to regenerate new blood cells compared with regular mice of the same age.