Key old-age gene found

When cells stop working ageing begins

A single gene could have a key role in the development of a number of age-related diseases such as Alzheimer's, arthritis and heart disease.

A research team at the University of Illinois in the United States say the gene called p21 seems to able to stop many other genes from working.

The gene is already known role is to stop cells continuing to reproduce after a certain number of divisions. This forms the natural ageing process.

But the researchers found that "turning on" the p21 gene actually brought on changes in numerous other genes.

Stopping p21 could help treat arthritis

Up to 40 other genes were inhibited, or stopped from working properly. These are involved in cell division and the reproduction of a cell's nucleus, thus immediately stopping cell growth.

But some of the genes stimulated by p21 activation produce proteins associated with age-related diseases.

Heart disease and arthritis

These include a chemical linked to beta-amyloid peptide, which is the component of the deposits found in the brains of Alzheimer's patients.

Other p21-activated genes produce various proteins and enzymes that contribute to heart disease and arthritis.

The research, in the journal the Proceedings of the National Academy of Sciences, holds out the prospect that treatments which modify the way that p21 works could have an effect on a wide range of age-related illnesses.

Professor Igor Roninson, professor in the department of molecular genetics at the University of Illinois at Chicago, said: "The pattern was striking. Turning on this one gene brought about changes in numerous other genes that have already been implicated in ageing and age-related diseases."

A spokesman for the Cancer Research Campaign said that turning on p21 was thought to be a method of inhibiting the growth of cancer cells in tissues, but that might have to be tempered if turning on the gene triggered other, less favourable changes.

Although on its own this study doesn't mean scientists have found a cure for old age it does suggest they are on the right track to understanding why our bodies start to break down as we get older.