Mesenchymal stem cells from different sources and their derived exosomes: A pre-clinical perspective

Since the introduction of cell therapy as a strategy for the treatment of many diseases, mesenchymal stem cells have emerged as ideal candidates, yet the underlying mechanisms of their beneficial effects are only partially understood. At the start of the 21st century, a paracrine effect was proposed as a mechanism of tissue repair by these cells. In addition, a role was suggested for a heterogeneous population of extracellular vesicles in cell-to-cell communication. Some of these vesicles including exosomes have been isolated from most fluids and cells, as well as from supernatants of in vitro cell cultures. Recent research in the field of regenerative medicine suggests that exosomes derived from mesenchymal stem cells could be a powerful new therapeutic tool. This review examines the therapeutic potential of these exosomes obtained from the sources most used in cell therapy: bone marrow, adipose tissue, and umbilical cord.