Effects of zinc supplementation and zinc chelation on the gene expression levels of ZnT-8. INS-1E cells were exposed to the indicated concentrations of ZnCl2(A) or TPEN (B) for 24 h in the presence of 11 mM glucose. The gene expression levels of ZnT-8 were normalized for β-actin, HSP, and Cltc in cells exposed to ZnCl2 and to HSP, CycA, and UBC-7 in cells exposed to TPEN. Data are shown as the mean ± SEM (n = 4–6). *P < 0.05.