Anti-inflammatory effects of mesenchymal stem cells: novel concept for future therapies

Background: Mesenchymal stem cells (MSC) are multipotent cells that can be isolated from the bone marrow and expanded in culture relatively easily. Culture-expanded MSC have been used in clinical settings to enhance hematopoietic stem cell engraftment in bone marrow transplant patients and in tissue regeneration therapy. More recently, the anti-inflammatory effects of MSC have generated a great deal of interest. Objective/methods: In this review we describe in vitro assays that have demonstrated how MSC regulate immune cell proliferation, differentiation and phenotype. We also highlight effector molecules produced by MSC that drive this function. In addition, we focus on animal models of lung injury, in which administration of MSC attenuates inflammation, and injury revealing a central role for MSC in mitigating pro-inflammatory networks and amplifying anti-inflammatory signals. Conclusions: The discoveries described herein have contributed to the novel concept of MSC as a therapeutic modality in inflammatory diseases, including acute lung injury.