Discovery opens new paths for regenerative medicine

For decades, scientists assumed that neural stem cells (NSC) only occur in the brain and spinal cord. A new international study, led by Hans Schöler of the Max Planck Institute for Molecular Biomedicine de Münster, has now refuted this hypothesis and has discovered a new type of neural stem cells outside the central nervous system (CNS) which opens Élogère Possibilities for the Development of Therapies for Neurological Diseases. The study is published in the journal Cellular biology of nature.

In 2014, an article entitled “Conversion of stimulating the stimulus of somatic cells in multiipotence” was published in Nature. This publication initially caused agitation because it opened a simple means of obtaining multi -patent stem cells. The induction of multipotent stem cells without the need for viral vectors, as Shinya Yamanaka did and for which he received the Nobel Prize, would have been too good to be true.

Although the Schöler’s laboratory of the Max Planck Institute of Molecular Biomedicine, like many others, tried to repeat the experience which described “the acquisition of pluripotence triggered by the stimulus” (STAP) based on the treatment of low -pH somatic cells. However, the generation of pluripotent cells failed, whatever the cultivation conditions and the tissues used – and the corresponding paper was finally retracted several months after the publication.

However, to the surprise of Dong Han and Schöler, they were able to use the Stap method to obtain a rare cellular population from the periphery of the central nervous system which presents the properties of neural stem cells (NSC). These NSCs, called peripheral neural stem cells (PNSC), were found in several mouse tissues, including lung and tail. Once the NSC population has been identified, it has become clear that low -pH treatment was not necessary to cultivate them.

A team of researchers of more than 10 laboratories in Europe, Asia and North America then examined these newly identified PNSCs: PNSCs share significant molecular and functional characteristics with the NSC of the brain.

PNSCs have the same cellular morphology, the same capacity for renewal and differentiation as the NSCs of the brain. They express several markers specific to the NSC and have transcriptional and epigenetic profiles at the genome scale which are consistent with those of NSC in the brain. In addition, many PNSCs that migrate outside the neural tube can differentiate in mature neurons and, to a limited extent, glial cells during embryonic and postnatal development.

The discovery of PNSCs provides not only new information on the development of the nervous system of mammals. Their existence also questions a long -standing hypothesis in neuroscience and, because they can be cultivated in substantial number in the Petri box, opens up new possibilities of regenerative medicine.

In addition, obtaining NSC from the brain is not a privileged method. On the other hand, obtaining NSC from other organs or tissues seems to be a viable and practical approach.

Schöler, the main author of the study, returns to the long road that led to this discovery: “It was the oldest project of my career. Originally, we wanted to reproduce the results of Stap published in Nature which were published more than 10 years ago, namely to induce multi -patent stem cells with a weak pH.

“Like the other laboratories, we could not reproduce this. But fortunately, our attempts were not in vain: we found peripheral neural stem cells previously unknown, which calls into question the long -term dogma that neural stem cells do not exist outside the central nervous system.

Han, the main researcher of the study, who carried out most of the experiences of this work as a member of the Schöler laboratory, underlined the possible implications of this result: “If these cells exist in humans and can spread indefinitely as they can in mice, they could have enormous therapeutic potential.

“This is particularly exciting because the accessible peripheral neuronal stem cells could provide a new avenue for neural repair and regeneration, bypassing many of the challenges associated with the supply of stem cells of the central nervous system.”

The discovery of PNSCs outside the SNC suggests a level of cell plasticity previously not recognized in the nervous system. Unlike stem cells derived from the neural crest, which have a limited self-renewal capacity, PNSCs closely resemble NSC derived from the brain and show the ability to maintain neurogenesis over an prolonged period.

Schöler highlighted the crucial role of interdisciplinary cooperation to make this discovery possible: “We have involved many laboratories in different areas of expertise to ensure that this study is waterproof.

Potential impact on human health and medicine

The capacity to exploit PNSC could have large -scale implications for the treatment of neurodegenerative diseases and strategies for repairing nerve cells. If PNSCs 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 lesions and other neurodegenerative disorders. Future studies will aim to establish the existence of PNSCs in humans and to explore their full therapeutic potential.

The results, published in the journal Cellular biology of natureThus opens the way to more in -depth research on the role of PNSC in human biology and their potential application in the treatment of neurodegenerative diseases and in regenerative therapies.