Figure 3.

Effects of cytokine and metabolic stress on proteins in different subcellular locations. A, immunoblotting analysis of total cell lysate from ∼2 × 10⁴ EndoC-βH1 cells with or without stress exposure as indicated. ZnT8 and α-tubulin were probed with respective antibodies at the same time on the same immunoblot. Two ZnT8 splice variants are marked as A and B, respectively. B, immunoblotting analysis of total cell lysate using antibodies to BAP31, calnexin, IA2, VAMP2, and TMED3 as indicated. C, immunoblotting analysis of total cell lysates using antibodies to GAD65 and SCD as indicated (top) and responses of four β-cell autoantigens and SCD to cytokine (red) or metabolic stress (green) as indicated (bottom). Respective protein band intensities were quantified and normalized to that of untreated controls on the same immunoblots. D, densitometric quantification of ZnT8, α-tubulin, and BAP31 at different time points of cytokine (red) and Glc + PA exposures (green). Protein band intensities were normalized to that of untreated controls on the same immunoblots. ***, statistical significance by paired t test with p < 0.001. Error bars, S.E. of eight measurements from four independent experiments.