Pancreatic Islet Transplantation
Subcapsular islet graft in the left kidney of a diabetic C57Bl/6J recipient mouse. The anesthesized mouse was shaved on the back and fumigated. Peritoneum was opened with a 1 cm cut and the kidney was carefully moved from the retroperitoneum to the skin surface. Under visual control the islets were injected by cannulating the kidney capsule with a catheter. Finally, the kidney was re-inserted into its normal position and skin was closed again. Pancreatic islet transplantation Pancreatic islet transplantation is a invasive therapy to functionally cure type 1 diabetes and its complications. Islets are isolated from a pancreas of a deceased human donor, and are infused into a diabetic patient’s liver via the portal vein. Hepatic deposition after intraportal injection is the preferred transplantation mode in clinical programs. The principle is shown in this figure and the experimental procedure in a recipient mouse is demonstrated in this video. https://www.jove.com/embed/directions/57559?key=d4v56h3b The goal is to provide a sufficient number of insulin releasing beta-cells to control blood glucose levels. Although the introduction of standardized protocols of islet isolation and transplantation has improved outcome both low efficiency and adverse effects restrict clinical application as a majority of recipients do not maintain long-term insulin independence and experience graft failure. Instant blood-mediated inflammatory reactions (IBMIR), which occur rapidly when isolated islets are infused to the portal vein and are in direct contact with blood, have been suggested to be responsible for acute islet destruction. IBMIR are clinically manifested by the formation of macro- and microthrombi and characterized by activation of platelets and the coagulation system. While platelet consumption and formation of a fibrin capsule around the islet is known to be one of the first events in IBMIR, the molecular mechanisms of platelet activation and their contribution to islet engraftment remain largely unknown. In instant blood mediated inflammatory reaction (IBMIR) platelet activation and formation of a fibrin capsule surrounding the islet is one of the first events. However, the mechanism behind activation and its contribution to islet destruction or engraftment is not clearly understood. Therefore, this study contributes to identify factors released by pancreatic islets, which can induce in vitro platelet activation and aggregation. OBJECTIVES 1. Interaction between pancreatic islets and platelets 2. Effect of inflammatory cytokines on induction of platelet aggregation 3. Role of platelet receptor GPVI in islet-induced platelet aggregation 4. Regulation of FXII expression in pancreatic islets with and without inflammatory cytokines treatment