Blood cells from an 80-year-old became neural stem cells with a molecular age under 20

Researchers at the University of Bonn have converted human blood cells directly into neural stem cells and found that the cells became dramatically younger in molecular terms: cells from an 80-year-old ended up with a molecular age of less than 20, the university said. The study was published in the journal Aging Cell.

Skipping the usual stem cell stage

Scientists can reprogram cells in the lab using a cocktail of transcription factors, proteins that switch on different genetic instructions. Rejuvenation during reprogramming was already known, but mainly in a two-step method in which cells are first turned into pluripotent stem cells, which can become almost any cell type, and then into neural stem cells.

The Bonn team, led by Professor Oliver Brüstle, instead turned red blood cell precursors directly into neural stem cells. They measured age using epigenetic clocks, which track chemical marks on DNA that change as people get older.

“In our approach, rejuvenation occurred gradually and could be tracked for over 100 days.” — Prof. Oliver Brüstle, Institute of Reconstructive Neurobiology, University Hospital Bonn

A slow reset that scientists can study

Because the clocks reset over several weeks rather than suddenly, the researchers say the method is a useful model for finding out which factors and drugs speed up or slow down cellular rejuvenation. Brüstle said that matters for brain research, since age is the biggest risk factor for neurodegenerative diseases such as Alzheimer's.

Lab research, not a treatment

The work involved cells in the lab, not people, and does not reverse ageing in the body. In earlier studies, nerve cells made this way connected with existing neurons when transplanted into mice. The research involved the University Hospital of Bonn, the University of Bonn and RWTH Aachen University. Brain cells are also the focus of other recent work, such as a single-neuron study of resilience in Parkinson's.