miRNA sequencing of  islet-drived exosomes  in HFD mice
After isolation, islets were cultured in a serum-exosomes-free culture media for one week. Collected culture media were centrifuged first at 300g for 20 min to pellets cells and then at 10000g for 20 min to discard dead cells and cell debris. Exosomes were then isolated from the supernatant by ultracentrifugation at 110000g for 70 min. Exosomes were collected in a minimal volume of PBS,and added three times the volume of Trizol LS to extract exosomes RNA. Overall design: miRNA profiles of islet-drived exosomes