A newly developed molecule causes ageing cells to commit suicide, restoring some signs of health and stamina in old mice.

Damaged cells that stop dividing, called senescent cells, accumulate with age, and are thought to contribute to inflammation, tissue damage and age-related diseases. To find ways to clear these cells, Peter de Keizer at the Erasmus University Medical Center in Rotterdam, the Netherlands, and his colleagues designed a peptide that impairs binding between the proteins FOXO4 and p53 — an interaction that normally inhibits the 'self-destruct' signal in senescent cells. Infusions of the peptide reversed decline in kidney function in aged mice, and eliminated weight loss and liver damage caused in mice by chemotherapy drugs. In mice with a premature-ageing condition, treatment with the peptide caused regrowth of fur that had been lost, and doubled how far the animals could run.

The peptide seemed to have little effect on normal cells, probably because FOXO4 is scarce in non-senescent cells. The researchers are now preparing to test the safety of their molecule in humans.

Cell 169, 132–147 (2017)