Researchers at the Max Planck Institute for Molecular Biomedicine in Münster have discovered neural stem cells outside the brain in mice, in peripheral organs such as the lungs, tail, and limbs, according to a report in the journal Nature Cell Biology.
For over a hundred years, science has maintained that neural stem cells—those responsible for generating new neurons—exist only in the central nervous system: the brain and spinal cord. This finding of a new type of neural stem cell outside the brain could revolutionize the treatment of neurodegenerative diseases.
These new cells, called peripheral neural stem cells (pNSCs), are very similar to brain stem cells. They self-renew, can transform into different types of nervous system cells, and have the same genetic signatures. But they have an important advantage: they are found in much more accessible tissues, which would facilitate their use in therapies without needing to access the brain.
One of the most surprising places they were found was in the lungs. Specifically, the researchers observed these cells aligned along the bronchi of both young and adult mice. There, the pNSCs displayed key proteins—such as Sox1 and Sox2, typical of neural stem cells—and could be cultured in the laboratory for more than 50 generations without losing their ability to form neurons, glial cells, and other components of the nervous system. They achieved this not only in culture but also when transplanted directly into the brains of mice.
Regarding the origin of these cells, genetic analysis showed that pNSCs do not originate from the neural crest (an embryonic structure known for generating peripheral tissues), but from neuroepithelial cells, the same ones that give rise to the central nervous system during embryonic development. This means they are a completely different cell population, challenging the traditional idea that neural stem cells exist only within the brain.
Beyond its scientific interest, this discovery could have very practical implications. Currently, neural stem cells are difficult to obtain and manipulate, which complicates their use in therapies. But pNSCs could be extracted from peripheral tissues without the need for invasive surgery, opening up a promising avenue for treating diseases such as Parkinson’s, spinal cord injuries, and Alzheimer’s disease.
If these cells also exist in humans and retain their properties, they could be used to generate neurons from the patients themselves, avoiding rejection problems and the use of embryonic stem cells for these purposes, thus representing a major advantage on the ethical level as well. The next step will be to verify whether these cells are present in human tissue. If they are, we would be witnessing one of the most important discoveries in neuroscience and developmental biology in decades.
Lucía Gómez Tatay
Bioethics Observatory – Institute of Life Sciences
Catholic University of Valencia
