Activated gene extends life by a third - in fruit flies

Activating a single gene can slow the ageing process and considerably extend life, scientists have discovered. However, the experiments to demonstrate this were performed in fruit flies, and any application in humans is likely to be extremely distant.

The study used flies in which the gene, called AMPK, could be activated in key organ systems rather than flies genetically engineered to have AMPK 'switched on' throughout their bodies. Increasing the activity of AMPK in the intestines extended the fruit flies' lifespans to eight weeks from the typical six.

Normally, AMPK works like an energy sensor and is activated when cellular energy levels are low. The scientists think that boosting AMPK prolonged lifespan by increasing a cellular process called autophagy. This process enables cells to discard 'cellular rubbish' - components that are damaged or aged. Activating AMPK in the flies led to autophagy occurring at a greater rate than usual.

Dr David Walker, associate professor at UCLA in the USA and senior author of the research, says that in humans certain neurodegenerative diseases, including both Alzheimer's and Parkinson's diseases, are associated with the accumulation of protein aggregates, a type of cellular rubbish.

A statement from the scientists explains: 'Delivering anti-aging treatments to the brain or other key organs could prove technically difficult. The study suggests that activating AMPK in a more accessible organ such as the intestine, for example, could ultimately slow the aging process throughout the entire body, including the brain'.

Translation of this kind of exploratory research into humans is exceptionally complex. For one thing, the AMPK gene is present in humans but is not activated at a high level. Upregulation may therefore have dangerous side effects not seen in flies.

Despite such difficulties, Dr Walker says the ultimate aim of his research is 'to promote healthy aging in people'.

'Instead of studying the diseases of aging - Parkinson's disease, Alzheimer's disease, cancer, stroke, cardiovascular disease, diabetes - one by one, we believe it may be possible to intervene in the aging process and delay the onset of many of these diseases'.

Dr Walker added that AMPK is thought to be a key target of metformin, a drug used to treat type 2 diabetes, with metformin activating AMPK.

The research was published in Cell Reports.