Scientists extend lifespan of mice by 35%
The secret is simply to remove worn-out āsenescentā cells that accumulate with age and have a destructive effect on the body, scientists found.
When this was done using a drug to activate a āsuicide geneā in genetically modified mice, the effects were dramatic. Treated animals not only lived 25% to 35% longer, but in many respects they were healthier too.
The mice were more active and their hearts and kidneys functioned better than mice left to age naturally.
Their body tissues and organs also bore less evidence of damaging inflammation, and grew fewer tumours.
Scientists are still not sure to what extent humans stand to benefit from the discovery. But a number of research groups are already on the hunt for senescent cell-targeting compounds that could form the basis of lucrative treatments.
US scientist Dr Darren Baker, who led the Mayo Clinic team behind the study, said: āIt is not far-fetched to think there will be things coming down the pipeline that influence or remove these senescent cells.ā
Senescent cells are potentially dangerous defective old cells that are prevented from dividing and enter a state of suspended animation.
But even though they no longer reproduce, they can still do harm
and are closely associated with age-related diseases and frailty.
The Mayo Clinic team wanted to see what would happen if middle-aged mice were protected against the effects of senescent cells.
A strain of transgenic mouse was created with a āsuicide geneā that targeted and killed off senescent cells when activated by a particular drug.
Even though senescent cells only made up a small fraction of the animalsā cell population, their removal had far-reaching effects.
Since the research technique relied on genetic engineering it could not directly be applied to humans, said Dr Baker.
But he knew of āa variety of groupsā that were trying to track down compounds which selectively wiped out senescent cells.
