Scientists identify chemical processes that lead to ageing

12 January, 2009 15:45:00

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The chemical processes critical to ageing have been identified by scientists, bringing the possibility of a longer life and smoother skin a step closer.

By Richard Alleyne

Researchers have found two connected chemical triggers that regulate the lifespan of cells and believe that, by influencing them, they can increase longevity and reduce the signs of ageing.

The study by Stanford University in California builds on the growing belief that age-related degeneration of tissues, organs and even facial skin, is an active, deliberate process by the body rather than a gradual failure of tired cells.

The team has found two proteins that seem to directly affect ageing. One - known as SIRT6 - which protects against cell ageing and another - known as NF Kappa B - which promotes it.

What is even more exciting is that the study has discovered for the first time that the two substances influence each other - and that manipulating their relative availability in the body could add years to the average life and reduce wrinkles.

The team believe that individuals naturally have different mixes of the substances in their bodies and this is why some people are genetically destined to live longer.

"There is a genetic process that has to be on, and enforced, in order for ageing to happen," said Dr Howard Chang, associate professor of dermatology at the school and a member of Stanford's Cancer Center (corr).

"It's possible that those rare individuals who live beyond 100 years have a less-efficient version of this master pathway, just as children with progeria – a genetic ageing disease – may have components of this pathway that are more active."

The study, which is published in the journal Cell, focused on two sets of mice: one of which was bred to be deficient of the protein SIRT6, and a second set of elderly mice which had the activity of the NF Kappa B blocked.

It was found that the first set aged rapidly and died after just four weeks due to an increase of the NF Kappa B in the system. Suppressing the latter reversed the ageing process.

Similarly in the second set of mice it was found that when NF Kappa was subdued they looked and acted younger.

The scientists concluded that SIRT6 and NF Kappa B may work together to help cells age appropriately as the former "puts the brakes" on the latter.

"It seems that an important job of SIRT6 is to restrain NF Kappa B and limit the expression of genes associated with ageing," said Dr Chang.