These findings will accelerate the use of these cells in regenerative medicine, with potential application in neurodegenerative diseases.
The Stem Cell Reports journal, belonging to the International Society for Stem Cell Research (ISSCR) and published by Cell Press, published in its online edition of 12th October a study carried out by researchers at Osakidetza’s Biodonostia HRI Tissue Engineering Group, headed by Ander Izeta and Araika Gutiérrez Rivera. The study identifies the origin of the cells which give rise to nervous tissue based on different adult tissues, such as skin. These findings will accelerate the use of these cells in regenerative medicine, with potential application in neurodegenerative diseases.
Stem cell therapy has enormous potential for treating myriad diseases, and for improving conditions in patients with as yet unsolved medical requirements. However, to obtain benefit from the therapeutic properties of stem cells protocols must be created which permit safe and efficient cell isolation and expansion. The nature of these cells is complex and the success of applications based on cell therapies largely lies in good characterisation of the cell therapy medicament. That is why progress in knowledge of stem cell biology is a must for developing new clinical therapies.
Skin is a highly regenerative tissue which hosts myriad stem cell populations. In recent years a source of dermic stem cells has been identified, with the capacity to regenerate skin and hair follicle, as well as giving rise to nervous system cells (neurons and glial), smooth muscle cells and adipose tissue. These stem cells (known as SKPs – skin-derived precursor cells – in scientific literature) could be used in therapeutic strategies based on autologous transplants for cell replacement, i.e. by taking the patient’s own stem cells and later returning them to the same person. They could also be used in studies to analyse the implication of stem cells in tumour development.
SKPs represent a pluripotent cell population in adults without the ethical drawbacks of embryonic stem cells and also has added advantages, such as the fact that they are easy to obtain by means of a small autologous skin biopsy, thereby avoiding problems of immune rejection.
In recent years, SKPs have been especially used to generate myelinating Schwann cells, a type of cell which covers the peripheral nerves which have the capacity to promote the axonal regeneration of neurons, in models of medullar lesion of the central nervous system. They have also been used to restore the myelinic sheaths of nerves when these are damaged due to mechanical lesions or as a result of diseases such as multiple sclerosis.
Nevertheless, despite having been the subject of numerous studies, the identity of SKPs and their embryonic origin have been a matter of great controversy and have not been clarified. The work carried out by the Tissue Engineering Group at the Biodonostia HRI, the first author of which is Haizea Iribar, demonstrates that SKPs represent a heterogeneous population, among which only a very small portion retain the capacity to generate nervous tissue. These cells with neurogenic potential are in fact dedifferentiated Schwann cells. In other words, they have taken on stem cell characteristics in response to the tissue lesion or damage, and therefore have the capacity to produce new nervous tissue cells.
These results have important implications in the scope of stem cells and highlight the need to increase knowledge of the biology of these cell populations in order to be able to apply them satisfactorily in clinical practice