Scientists at the Babraham Institute in Cambridge have found a way to make old human skin cells behave as though they are about 30 years younger, without turning them into stem cells. Using a modified version of a Nobel Prize–winning stem cell technique, they briefly exposed adult skin cells (fibroblasts) to a set of reprogramming molecules known as Yamanaka factors, but stopped the process early. After 13 days, the cells had shed many molecular signs of aging yet were still able to regain their identity as skin cells. Tests showed that these “rejuvenated” cells more closely matched the biological profile of much younger cells when scientists looked at chemical tags on DNA (the epigenetic clock) and patterns of gene activity (the transcriptome).

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