Potential roles of mesenchymal stromal cells in islet allo‐ and xenotransplantation for type 1 diabetes mellitus

Abstract Islet transplantation is poised to play an important role in the treatment of type 1 diabetes mellitus (T1DM). However, there are several challenges limiting its widespread use, including the instant blood‐mediated inflammatory reaction, hypoxic/ischemic injury, and the immune response. Mesenchymal stem/stromal cells (MSCs) are known to exert regenerative, immunoregulatory, angiogenic, and metabolic properties. Here, we review recent reports on the application of MSCs in islet allo‐ and xenotransplantation. We also document the clinical trials that have been undertaken or are currently underway, relating to the co‐transplantation of islets and MSCs. Increasing evidence indicates that co‐transplantation of MSCs prolongs islet graft survival by locally secreted protective factors that reduce immune reactivity and promote vascularization, cell survival, and regeneration. MSC therapy may be a promising option for islet transplantation in patients with T1DM.