Figure 9.

Effect of prolonged proteasome inhibition on FOXA2 protein expression in cultured human islet cells. Western blot analysis of FOXA2 and hIAPP protein levels in the whole-cell extracts of human islet cells following progressive (0–12 h) inhibition of proteasome activity by LC was performed. Human islet cells were cultured in 5 and 20 mm glucose (Glc)-containing media for 5 days, followed by proteasome inhibition with LC for additional 0–12 h. A separately imaged region with enhanced signal for hIAPP under the normal (5 mm) Glc levels is presented below the original Western blotting. Samples of 5 or 20 mm glucose-containing media are separated by one empty lane in the Western blotting. Significance was established at *, p < 0.05; **, p < 0.01 (control versus LC + 5 mm Glc); and ##, p < 0.01 (control versus LC + 20 mm Glc); @@, p < 0.01 (1 h LC + 20 mm Glc versus LC (6 and 12 h) + 20 mm Glc), n = 3, ANOVA followed by Tukey's post hoc comparison test.