Cells taken from an 80-year-old person regained, in the laboratory, a molecular age below 20. And that was not even the purpose of the research.
This transformation was achieved by researchers at the University of Bonn, Germany. Their goal was to create cells capable of giving rise to neurons from a simple blood sample. But while conducting their experiment, they observed another change: the cells also appeared to rejuvenate.
In our bodies, a blood cell does not play the same role as a brain cell. Yet they possess almost the same instructions in their DNA. The difference mainly comes from the part of those instructions they use. In the laboratory, researchers know how to modify this process to make certain cells change roles.
The team thus transformed precursor cells of red blood cells into neural stem cells. These can then produce nerve cells. During this transformation, the researchers observed that several signs of aging gradually disappeared.
To verify this, they focused on small chemical marks present on DNA. These marks change with age without altering the genes themselves. By measuring them, it is possible to estimate the biological age of cells, which does not always correspond to the person’s actual age.
The results were particularly striking with cells from an 80-year-old donor. After their transformation, the measurements assigned them an age below 20. The researchers found this phenomenon in samples from people of various ages, including a 101-year-old donor.
Another surprise: this reversal does not happen all at once. The cells first begin to adopt their new function, then continue to rejuvenate for several weeks. The phenomenon can be monitored beyond 100 days, giving researchers time to understand the changes taking place.
For now, the experiment concerns only cells cultured in the laboratory, and their age is estimated using biological markers. However, this method could help researchers better study the aging of brain cells and the mechanisms involved in diseases such as Alzheimer’s.