Figure 1.

Role of Zn in barrier functions in Caco-2 and A549 cells. Caco-2 and A549 cells were seeded at 30,000 cells per well and cultured in 3.0 μm transwell inserts for 4 days. (A) Comparison of zinc uptake in Caco-2 and A549 cells treated apically with 100 μM ZnSO₄ in 2% media for 24 h. (B) TEER of Caco-2 cells grown for 7 days treated with ZnSO₄ at 100 μM by apical, basolateral or apical + basolateral regions in 2% DMEM for 24 h. (C) Corresponding fold change in zinc levels in Caco-2 cells measured by FLZ-3AM staining at 24 h post treatment. (D) Percentage of dead cells in apical, basolateral, and apical + basolateral ZnSO₄ treated Caco-2 cells at 24 h measured by live dead stain using flow cytometry. Data are from at least two independent experiments and represent mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001.