Mesenchymal Stem Cells potentiate the feasibility of pancreatic islets transplantation through a double action

Transplantation of pancreatic islets is an innovative and promising clinical option to treat patients with type 1 diabetes [1]. This is a minimally invasive therapeutic approach, which allows a good metabolic control and a long-term insulin independence [2]. The therapeutic feasibility of pancreatic islets transplantation is however limited by the poor yield of pancreatic islet explants and even more the immune graft rejection, which have as a consequence the very limited lifespan of transplanted tissue [3]. To avoid these side effects besides the treatment with immunosuppressive drugs, promising results have been obtained in vivo with the use of Mesenchymal Stem cells (MSCs), already known in literature to be able to support the cellular survival through direct contact [4, 5] by the release of trophic factors [6], and by their immunomodulatory properties [7]. By means of these particular features it can be surmised that MSCs may improve the survival of pancreatic islets and, therefore, the success of the transplantation. Several in vivo studies have demonstrated the positive effect of islet-MSC co-transplantation in diabetic rats, but the mechanisms of these encouraging results are still unknown [8]. In this in vitro study we shed light on the concealed molecular mechanisms of MSC positive action, by analyzing the effect of both direct and indirect co-cultures of rat MSCs with pancreatic islets.