Exosomes from β-cells alleviated hyperglycemia and enhanced angiogenesis in islets of streptozotocin-induced diabetic mice.

Purpose: Exosomes are small nanoscale vesicles secreted from cells. Exosome-based therapeutic approaches have been evaluated in treating ischemic diseases. In the present study, we explored the effect of exosomes on streptozotozin (STZ)-induced diabetic mouse and its underlying mechanisms. Methods: Exosomes were isolated from MIN6 cells. Transmission electron microscopy, dynamic light scattering and Western blot were used to identify the exosomes. STZ was used to establish diabetic or abnormal glucose tolerance mouse model. Histology study and flow cytometry were applied to detect the changes in immune responses. Results: Transplantation of the exosomes into diabetic mice resulted in a longer median survival time compared with the untreated diabetic mice (P<0.01). Transplantation of the exosomes improved glucose tolerance, increased insulin content and preserved the architectures of islets in mice with abnormal glucose tolerance. Moreover, exosome treatment enhanced the expression of CD31, a marker of endothelial cells, and tended to reduce macrophage infiltration in islets of STZ-treated mice. Conclusion: Exosomes derived from beta-cells play a role in preserving pancreatic islet architecture and its function, and in inducing islet angiogenesis, which implicates that exosome treatment could be a novel therapeutic strategy for diabetes.