Murine Islet Dissociation and Tunicamycin Treatment

Whole islets were isolated from NOD mice as described and dispersed for 3 min at 37°C using non-enzymatic cell dissociation buffer (Millipore Sigma). Cells were collected by centrifugation, washed with PBS, and counted. Cells were resuspended in DMEM/10% FBS low-glucose media (1 g/L glucose, Gibco, D10F-LG) and split into 1.0 mL aliquots in microfuge tubes for treatment overnight at 37°C in D10F-LG or D10F-LG containing 100 µM tauroursodeoxycholic acid (TUDCA; Millipore Sigma). Tunicamycin (Millipore Sigma) was added at 1 µg/mL to appropriate samples and was incubated for 2 h at 37°C, after which cells were collected, washed, and counted for antigen assays.