Purpose of review: In recent years, the multilineage differentiation potential of mesenchymal stem cells (MSCs) in combination with their highly immunosuppressive properties has been extensively studied and exploited for a number of diseases. Here, we review the recent findings supporting the therapeutic use in the clinic and the mechanisms by which MSCs may deliver such an effect.
Recent findings: The results of using MSCs for tissue repair have been controversial in both humans and animal models. Despite the successful manipulation in vitro, MSCs fail to consistently differentiate at the site of lesion. However, there is evidence that paracrine mechanisms eventually drive tissue repair. Conversely, MSCs have been used with great success in the clinical treatment of severe graft-versus-host disease, and animal models suggest that they may be equally effective in a variety of autoimmune diseases. The therapeutic efficacy of MSCs depends on a licensing stage provided by the inflammatory microenvironment, which makes MSCs tolerogenic.
Summary: Although encouraging, the therapeutic potentials of MSCs warrant further studies. In particular, the optimization of their in-vitro expansion and the characterization of disease-specific environment in which MSCs exert their function will provide crucial information to maximize their beneficial effects.