Peripheral nerve injury: molecular pathophysiology and prospects for restorative treatment by means of cell transplantation: a literature review

Abstract

Peripheral nerve injury (PNI) is a fairly common pathology—PNI accounts for 1-5% of all peacetime injuries and 12% of all combat injuries. This injury leads to disability, the development of chronic pain syndromes and a significant deterioration in the quality of life of the victims. Unfortunately, at present, in the case of the most frequent type of combat trauma — damage to the limbs — PNI treatment is mostly done last, "on the residual principle." Modern means of surgical and conservative treatment of PNI do not provide complete restoration of lost functions, therefore, restorative treatment of PNI is an urgent biomedical problem. The article reviews the currently known molecular mechanisms of various stages of PNI, as well as the plasticity of the central parts of the nervous system on the background of this injury. The main reasons for the limitation of autogenous recovery of functions after a sustained PNI are described — the absence of a relevant spatial organization of regrowth of axons in the area of PNI; post-traumatic death of neurons of spinal nodes and central parts of the nervous system; failure of plastic reconstruction of brain and spinal cord neural networks; irreversibility of atrophy of denervated muscles. Based on this, it was established that the means of restorative treatment of PNI should touch not only the epicenter of PNI, but also the central parts of the nervous system and denervated muscles. Mesenchymal stem cells (MSCs) are well-known means of a positive influence on the the restorative process in the focus of PNI, as well as a source of supportive influence/ strengthening effect and an amplifier of the plasticity of brain neural networks, which makes these cells a promising element of bioengineering treatment of PNI. The effect of MSCs on the central parts of the nervous system in case of PNI remains the least studied. Data from the literature indicate that such an effect can provide support for secondarily affected neurons and stimulate the plastic reorganization of brain networks, i.e., in general, significantly improve the results of restorative treatment of PNI.