Plate Nº 55 · recorded October 9, 2026
Biology & EvolutionReported finding
Blood Cells From an 80-Year-Old Rejuvenated to Under 20 in the Lab
Researchers in Bonn turned blood cells from an 80-year-old donor into neural stem cells with a molecular age of less than 20 years — and the slow pace of the reset offers a new window into how aging might be reversed.
By Marcus Bennett4 min read888 words
In brief
- Blood cells from an 80-year-old donor were reprogrammed into neural stem cells with a molecular age of under 20 years.
- The rejuvenation occurred gradually and could be tracked for over 100 days, roughly 60 years of molecular de-aging in about 50 days.
- The study was published in Aging Cell (2026), first author Lea Jessica Berg, DOI: 10.1111/acel.70751.
- Dr. Oliver Brüstle of the University Hospital of Bonn led the research at the Institute of Reconstructive Neurobiology.
- The method bypassed the pluripotent stem cell stage used in earlier two-step reprogramming approaches.
Blood cells taken from an 80-year-old donor have been converted into stem cells with a molecular age of less than 20 years. Researchers at the University Hospital of Bonn and the University of Bonn achieved the dramatic rejuvenation in a test tube by directly reprogramming the cells, and they published their results in the journal Aging Cell (2026; DOI: 10.1111/acel.70751).
The team transformed red blood cell precursors into neural stem cells — the type of cell from which neurons can be grown. Along the way, the cells' "molecular clocks," which track chemical signs of aging on DNA, rolled back by roughly six decades in about 50 days.
What did the researchers actually do?
Every cell in the human body — whether skin, liver or blood — carries the same genetic material, because all of them descend from the same fertilized egg. But during development, each cell commits to a specific identity. A skin cell cannot naturally become a liver cell, and a blood cell cannot become a nerve cell.
Laboratory techniques can now undo that commitment. Scientists use a cocktail of transcription factors — proteins that switch genes on or off — to force a cell to read different genetic instructions and embark on a new developmental path. This approach has already made it possible to grow nerve tissue from skin cells, with the long-term goal of treating neurodegenerative diseases.
"Using this method, we have directly converted red blood cell precursors into neural stem cells," said Dr. Oliver Brüstle, director of the Institute of Reconstructive Neurobiology at the University Hospital of Bonn. In earlier work, his group showed that nerve cells produced this way form connections with existing neurons after transplantation into mouse brains.
The new study, however, looked at a different phenomenon.
"In our current study, however, we focused on a different phenomenon: namely, the observation that cells become significantly rejuvenated during reprogramming," said Brüstle, who is also a member of the Transdisciplinary Research Area (TRA) Life & Health at the University of Bonn.
How do you measure a cell's age?
The researchers used so-called molecular clocks. These clocks do not read the DNA sequence itself but track chemical modifications that accumulate on DNA as a person ages. The changes leave the genetic information intact; instead, they alter how frequently that information is read — a field known as epigenetics.
The reprogramming reset these epigenetic clocks substantially. Cells from an 80-year-old donor emerged with a molecular age of under 20 years.
"We also know that this epigenetic rejuvenation ensures that the cells actually behave like young cells," Brüstle said. In other words, the cells did not merely look younger on paper — their behavior matched.
Why the slow pace matters
Scientists already knew that reprogramming can rejuvenate cells. But until now, they had observed this effect only with a two-step method. In that approach, a blood cell is first converted into a pluripotent stem cell — a kind of master cell that can develop into almost any cell type in the body. That stem cell is then guided to become a neural stem cell, which can produce only brain cells.
Rejuvenation happens very quickly with that two-step technique — too quickly to study in detail.
"In contrast, we converted blood cells directly into neural stem cells — that is, without first passing through the pluripotent cell stage," Brüstle explained. "In our approach, rejuvenation occurred gradually and could be tracked for over 100 days."
That slow-motion reset is the study's key advantage. Because the epigenetic clocks wind back over several weeks rather than in a flash, researchers can watch the process unfold step by step.
"Rejuvenation that extends over such a long period of time is ideal as an experimental model: Since the epigenetic clocks are slowly reset over several weeks, we can use this model to investigate which factors and active substances accelerate or slow down the rejuvenation process," Brüstle said.
In practical terms, the system could serve as a testing ground for compounds that might speed up — or hold back — cellular rejuvenation.
What could this mean for neurodegenerative disease?
The findings are particularly relevant for neuroscience.
"After all, age is the most important risk factor for neurodegenerative diseases such as Alzheimer's," Brüstle noted.
The long-term hope is that understanding and controlling cellular rejuvenation could eventually support new approaches to age-related brain disorders. Previous work from the same Bonn group already showed that nerve cells derived this way can integrate into brain tissue after transplantation into mice.
What the study does not show
The results come from cells in a test tube, not from a therapy. The experiments demonstrate that direct reprogramming resets epigenetic age and produces young-behaving cells in a dish, and that the gradual nature of the process makes it a useful laboratory model. The study does not claim that the technique can treat or prevent Alzheimer's or any other disease in people.
Still, the approach gives researchers something they previously lacked: a stretched-out, observable timeline of cellular de-aging in human cells. First author Lea Jessica Berg and colleagues report the full findings in Aging Cell.
For a field where the most important risk factor — aging itself — has long resisted manipulation, a 60-year molecular rollback, tracked day by day, is a meaningful experimental foothold.
via Medical Xpress (Source)