Abstract
Mesenchymal stem cells (MSCs) are emerging as a promising therapeutic approach of cell-based therapy for a wide range of autoimmune disorders and degenerative diseases. In preclinical and clinical studies, MSCs have been shown to be highly efficient in treating graft-versus-host disease, systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, myocardial infarction, liver cirrhosis, inflammatory bowel disease, and other disorders. The underlying therapeutic mechanisms of MSCs include their homing efficiency to the tissue injury sites, their differentiation potential, their capability to produce a large amount of trophic factors, and their immunomodulatory effect. Because tissue damage sites are complicated milieus with distinct types of inflammatory cells and factors, available data have demonstrated that the properties of MSCs could be fundamentally influenced by the inflammatory elements. Thus, an understanding of the interaction between MSCs and the inflammatory microenvironment will provide critical information in revealing the precise in vivo mechanisms of MSC-mediated therapeutic effects and designing more practical protocols for clinical use of these cells.