Sources and Therapeutic Strategies of Mesenchymal Stem Cells in Regenerative Medicine

Abstract

During the past decade, mesenchymal stem cells (MSCs) have made their mark as a potential weapon in regenerative medicine. Since their first isolation by Friedenstein in the late 1970s of the last century, MSCs have opened new avenues in the field of regenerative medicine. The main fascination about MSCs lies in their ease of isolation and large ex vivo expansion capacity, as well as demonstrated multipotency and immunomodulatory activities. Basically, several reports have proved that MSCs isolated from different sources possess different characteristics and potentials. In addition, the mechanisms by which these cells can help regenerate tissues and treat several diseases have been proved to be far more complicated than ever thought of. Moreover, a growing body of research has revealed that the therapeutic effects of MSCs occur largely via paracrine signaling and secreted extracellular vesicles, which act as “signalosomes” controlling fundamental cellular functions in recipient cells. In this chapter, we will discuss how MSCs isolated from different sources such as bone marrow; the prototype MSCs, adipose tissue, and umbilical cord differ in their characteristics as potential sources of allogenic versus autologous cell therapy options. Besides, we will clarify the main documented mechanisms of action which MSCs play in regenerative medicine including their differentiation to tissues of mesenchymal versus non-mesenchymal lineages. Additionally, the immune-modulatory effects of MSCs will be discussed as an important arm in their therapeutic potential. Finally, we will discuss the potential of extracellular vesicles produced by MSCs as an emerging cell-free alternative to stem cells therapy.