The Possibility of Adiponectin in Islet Transplantation

Abstract Islet transplantation (ITx), a promising therapy for severe diabetes mellitus, needs further evolution. Adiponectin, an adipokine that regulates lipid and glucose metabolism, has some benefits that may improve (e.g., reinforcement of insulin-releasing function). This study attempted to evaluate the possibility of adiponectin for ITx improvement. Mouse islets were treated with 10 µg/mL recombinant mouse adiponectin by overnight culture (defined as adiponectin (+)). The islets’ insulin-releasing, angiogenic, and adhesion functions were assessed and compared with islets without adiponectin treatment (adiponectin (−)). Furthermore, 80 syngeneic islets, with or without adiponectin treatment, were transplanted into the renal subcapsular space of diabetic mice. In vitro assessment showed improved insulin-releasing, angiogenic, and adhesion functions adiponectin (+). Moreover, released insulin volume at high glucose stimulation, insulin content, and expressions of vascular endothelial growth factor and integrin β1 were improved in islets with adiponectin treatment. Furthermore, the ITx therapeutic effect with adiponectin treatment was partial. There was a significant improvement in blood glucose levels in adiponectin (+). No significant differences were noted in plasma insulin and area under the curve of blood glucose level in glucose tolerance test. In conclusion, adiponectin has various usefulness for improving ITx outcomes. Thus, further studies are necessary for this possibility.