A "longevity gene" can help boost the production of blood cells by reversing the decline of stem cells in old age, a study suggests.

Blood-generating stem cells become slower in old age, increasing stress on the body, but infusing them with a gene linked to the ageing process can restore them to a more youthful state, researchers found.

The study, which was performed in mice, raises the possibility of new treatments for degenerative diseases which occur with age, such as Alzheimer's.

More research will be needed to determine whether the findings in mice also apply to humans, but scientists claimed they could lead to the development of a "molecular fountain of youth".

Scientists from the University of California, Berkeley found that SIRT3, a protein from a class known as sirtuins which has previously been linked to ageing, could actually help "reverse" the natural process.

They examined the functioning of blood stem cells, which help keep the blood system healthy, on mice which had lacked the gene responsible for producing SIRT3.

The study, published in the Cell Reports journal, showed that for young mice the absence of SIRT3 made no difference, but older mice without the gene had fewer blood stem cells and were less able to produce new blood cells.

This could be because older mice were more vulnerable to "oxidative stress", a harmful sideeffect of the metabolism, and needed their antioxidant system, which is boosted by SIRT3, to counteract it, researchers said.

When levels of SIRT3 were raised in older mice, their blood cells were rejuvenated and production of blood cells improved.

Dr Danica Chen, who led the study, said: "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.

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New 'Longevity Gene' Can Reverse Age-Related Issues In Mice

Jan. 31, 2013 A new study led by researchers at the University of California, Berkeley, represents a major advance in the understanding of the molecular mechanisms behind aging while providing new hope for the development of targeted treatments for age-related degenerative diseases.

Older and fitter? New findings from a UC Berkeley-led study could have implications for the development of 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. The findings were published online on Jan. 31, in the journal Cell Reports.

The biologists 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 aging, but our study is really the first one demonstrating that sirtuins can reverse aging-associated degeneration, and I think that's very exciting," said study principal investigator Danica Chen, UC Berkeley assistant professor of nutritional science and toxicology. "This opens the door to potential treatments for age-related degenerative diseases."

Chen noted that over the past 10 to 20 years, there have been breakthroughs in scientists' understanding of aging. Instead of an uncontrolled, random process, aging is now considered highly regulated as development, opening it up to possible manipulation.

"A molecular fountain of youth"

"Studies have already shown that even a single gene mutation can lead to lifespan extension," said Chen. "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 aging? This is something we're hoping to understand and accomplish."

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 aging process becomes increasingly clear. Notably, SIRT3 is found in a cell's mitochondria, a cell compartment that helps control growth and death, and previous studies have shown that the SIRT3 gene is activated during calorie restriction, which has been shown to extend lifespan in various species.

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Longevity Gene: Discovery opens the door to a potential 'molecular fountain of youth'

Two papers published in international journals by researchers from the Tata Institute of Fundamental Research (TIFR) have resolved the long-standing controversy about the gene SIR2, the researchers said.

The studies show that SIR2 has anti-ageing properties and can combat ageing and age-related diseases, but it works only on a low-calorie diet. The gene is found in living organisms, including human beings. The findings have been published in the January editions of Cell Reports and Molecular and Cellular Biology.

A low-calorie diet positively impacts this gene in the human body, which subsequently provides protection from diseases like diabetes, obesity, cancer, Alzheimer's, Parkinson's and cardiovascular diseases, and promotes "healthy ageing", says the study.

The gene has been at the centre of a global controversy for many years, with one school of scientists saying it extends lifespans, while another school disagrees. The arguments questioned the relevance of expensive drugs to mimic the effect of this gene to defy ageing and age-related diseases. The new study shows SIR2 has anti-ageing properties.

"Our study resolves the hotly debated controversy about the role of SIR2 as a longevity gene. We have found that it may slow down the ageing process, but it may not directly increase the number of years one lives. We found a low-calorie intake has a significant impact on SIR2 protein and helps the body combat age-related diseases," said Dr Ullas Kolthur from TIFR's Department of Biological Sciences, and principal investigator of the study.

In a liver equivalent tissue, the gene helps in achieving metabolic and energy balance, and mediates beneficial effects throughout the body. The study, however, showed that high-calorie food adversely impacted the gene, and it was not able to protect the body from a series of diseases associated with old age and bad eating habits.

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'Longevity gene works, but you must eat right'