Mesenchymal stem cells in pancreatic islet transplantation

Islet transplantation is a method to restore ß cell mass and achieve glucose homeostasis in type 1 diabetic patients. It represents a minimal invasive approach for ß cell replacement, but long term blood glucose control is still largely unachievable. This phenomenon can be mainly attributed to the delayed and insufficient islet revascularization resulting in permanent cell death and contributing to early graft failure. Moreover, immunosuppressive drugs have made allograft possible, but there are many potential side effects associated with their use. In addition, the recurrence of immune response after transplantation is major challenge to the application of islet transplantation. Mesenchymal stem cells (MSCs) are known to be capable of releasing growth factors contributing to an increase in angiogenesis and stabilization of the vasculature and to enhance proliferation of endothelial and smooth muscle cells. They have also immunomodulatory function, both in vitro and in vivo, and offer therapeutic potential for achieving transplantation tolerance. This review will discuss the impact of MSCs on islet transplantation and focus on the potential role of MSCs in protecting islet grafts from both early graft failure and from autoimmune attack.