Eradicating Aging Cells Could Prevent Disease

For more than a decade, researchers have believed that aging cells damage the tissue around them, and that this damage underlies a number of age-related disorders. Now a new study in mice appears to confirm this. The study shows that selectively eliminating those aging, or "senescent," cells, could help prevent the onset of everything from muscle loss to cataracts.

Senescent cells can no longer divide, and therefore fail to replenish aging tissue. More recently, researchers have suggested that these cells might be secreting damaging chemicals that poison the cells around them. To determine their role in the diseases of aging, scientists at the Mayo Clinic in Rochester, Minnesota, identified senescent cells in mice that had been genetically engineered to age rapidly using a biomarker, called p16Ink4a, specific to these cells. For the length of the animals' lives, they were injected with a drug that induced only those biomarker-containing senescent cells to commit suicide, while leaving others untouched.

The results were striking: in tissues that contained the labeled cells, including everything from fat to muscle to eyes, selective removal appeared to postpone age-related damage. Treated mice had no cataracts, and showed increased muscle mass, strength, and subcutaneous fat when compared to mice that hadn't received the drug.

"We've shown there is a causal link between these senescent cells and age-related decline in tissue function," says Jan van Deursen, the Mayo Clinic cancer researcher who led the study. "It's a proof of principle that if you remove this particular cell type from an organism—we did it in a mouse but it will probably hold true for humans—tissues and organs would function better and would be more resistant to aging."