Researchers from the University Hospital of Bonn and the University of Bonn have succeeded in dramatically rejuvenating human cells in a test tube. To do so, they directly reprogrammed red blood cell precursors into stem cells from which neurons can be derived. During this process, the molecular clocks that indicate a cell’s age were reset. For example, blood cells from an 80-year-old were transformed into stem cells with a molecular age of less than 20 years. Since this rejuvenation process occurred very slowly, it is well-suited for a more detailed investigation of the underlying mechanisms. The results have been published in the journal Aging Cell.

The human body contains hundreds of different cell types. They all originate from the fertilized egg and therefore share the same genetic makeup. However, in the course of their development, they were committed to a specific fate: a skin cell cannot naturally become a liver cell, nor can a blood cell become a nerve cell.

Today, however, it is possible to reverse this determination in the laboratory. For example, nerve tissue can be grown from a skin cell, which may one day be used to treat neurodegenerative diseases. To achieve this reprogramming, researchers use a cocktail of various transcription factors. These factors cause the cell to read different genetic instructions and thus embark on a different developmental path.