The transplantation of mesenchymal stem cells derived from unconventional sources: an innovative approach to multiple sclerosis therapy

In recent years, in the effort to find a potential innovative therapy for multiple sclerosis (MS), researchers focused on transplantation of mesenchymal stem cells (MSCs) due to their well-recognized ability to suppress inflammatory/autoimmune responses and exert neuroregenerative properties. MSCs are a heterogeneous subset of pluripotent non-hematopoietic stromal cells that can be isolated from many different adult tissues, characterized by the capability to differentiate into various cell lineages, and to translocate into damaged areas, providing immunomodulatory effects. To date, several encouraging results were obtained mainly from the use of MSCs derived from the bone marrow (BM-MSCs) in experimental models of MS as well as in clinical trials. However, their use in clinic is limited due to the invasive collecting procedure and the low yield of viable stem cells. Consequently, these restrictions have prompted researchers to look for alternative tissue sources for stem cells such as adipose tissue, fetal annexes, and dental tissues that could represent a novel therapeutic option for MS treatment. Here, we provide an overview of the current knowledge about the most explored BM-MSCs in MS treatment in experimental and clinical studies. Moreover, we propose that unconventional sources of stem cells, which show characteristics similar to that of BM-MSCs, and being less invasive for removal, could be considered an excellent alternative to BM-MSCs and thus could be a promising innovative approach for MS treatment