The detection of peripheral neural stem cells could transform the treatment of Parkinson's disease and spinal cord injuries
Identification of peripheral neural stem cells (pNSCs) in the mouse lung. A) pNSCs distribute along the bronchial of mouse postnatal (image) and adult lung. These cells are specifically marked by Sox1 and co-express Sox2. B) pNSCs can be isolated from the lung and can be cultured in vitro for at least 50 passages.
© MPI for Molecular Biomedicine / Dong Han
To the point
- Peripheral neural stem cells: Researchers have discovered a new type of neural stem cell in the lungs of mice. These cells have similar properties to the known neural stem cells in the brain, including self-rejuvenation and differentiation ability.
- Surprising finding: The identification of these cells challenges the long-held assumption that neural stem cells only exist in the brain and spinal cord.
- New approaches to regenerative medicine: Harvesting peripheral neural stem cells may be more feasible than obtaining them from the central nervous system. If peripheral neural stem cells also exist in humans, they could potentially be used to treat diseases such as Parkinson's, spinal cord injury and other neurodegenerative disorders.
A team of researchers from more than ten laboratories in Europe, Asia and North America examined newly identified cells in mice called peripheral neural stem cells. These cells share important molecular and functional characteristics with neural stem cells of the brain. Peripheral neural stem cells have the same cell morphology, self-renewal and differentiation capacity as neural stem cells of the brain. They express several specific markers and have genome-wide transcriptional and epigenetic profiles that are consistent with those of neural stem cells in the brain. Furthermore, many peripheral neural stem cells that migrate out of the neural tube can differentiate into mature neurons and, to a limited extent, glial cells during embryonic and postnatal development.
The discovery of the new cell type not only provides new insights into the development of the mammalian nervous system. Their existence also challenges a long-standing hypothesis in neuroscience and, because they can be grown in substantial numbers in the petri dish, opens up new possibilities for regenerative medicine. Furthermore, obtaining neural stem cells from the brain is not a favoured method. By contrast, obtaining neural stem cells from other organs or tissues appears to be a viable and practical approach. "This was the longest-running project in my career. Originally, we wanted to replicate experiments that were published more than 10 years ago, namely, to induce pluripotent stem cells through low pH. Like other laboratories, we were unable to reproduce this. But fortunately, our attempts were not in vain: We found previously unknown peripheral neural stem cells, challenging the long-held dogma that neural stem cells do not exist outside the central nervous system," says Hans Schöler from the Max Planck Institute for Molecular Biomedicine and the senior author of the study.
Dong Han, the lead researcher of the study, who carried out most of the experiments in this work as a member of Schöler's laboratory, emphasised the possible implications of this result: "If these cells exist in humans and can be propagated indefinitely as they can in mice, they could have enormous therapeutic potential. This is particularly exciting because accessible peripheral neural stem cells could provide a new avenue for neural repair and regeneration, bypassing many of the challenges associated with sourcing stem cells from the central nervous system."
Plasticity in the nervous system
The discovery of peripheral neural stem cells outside the central nervous system suggests a previously unrecognised level of cellular plasticity within the nervous system. In contrast to neural crest-derived stem cells, which have a limited self-renewal capacity, peripheral neural stem cells closely resemble brain-derived neural stem cells and show the ability to sustain neurogenesis over an extended period of time.
Hans Schöler emphasised the crucial role of interdisciplinary cooperation in making this discovery possible: "We involved many laboratories with different areas of expertise to ensure that this study is watertight. The combination of genetic lineage analysis, single-cell analysis and functional tests in vivo provides compelling evidence that these peripheral neural stem cells are a genuine and previously unrecognised component of the mammalian nervous system."
Potential Impact on Medicine
The ability to harness peripheral neural stem cells could have far-reaching implications for the treatment of neurodegenerative diseases and nerve cell repair strategies. If such cells exist in humans, they could provide an easily accessible source of neural stem cells that could be used in the future to treat diseases such as Parkinson's disease, spinal cord injury and other neurodegenerative disorders. Future studies will aim to establish the existence of peripheral neural stem cells in humans and explore their full therapeutic potential. The results thus pave the way for further research into the role of these cells in human biology and their potential application in the treatment of neurodegenerative diseases and in regenerative therapies.
