Figure 2.

Measures informative of epithelial barrier function in HT-29 cells treated with ${\text{AlCl}}_3$. (A) Cell monolayers were treated with ${\text{AlCl}}_3$ ($2\text{\hspace{0.17em} mM}$, up to $24\mathrm{h}$) with or without pretreatment with N-acetylcysteine (NAC) ($5\text{\hspace{0.17em} mM}$, $1\mathrm{h}$) or PD98059 (PD) ($20\mathrm{\mu }\mathrm{M}$, $1\mathrm{h}$). Transepithelial electrical resistance (TEER) was measured in the cells ($n=3\text{\hspace{0.17em} wells}/\text{group}$). (B and C) Gene and protein expression of tight junction molecules. The cells were treated with ${\text{AlCl}}_3$ ($0–4\text{\hspace{0.17em} mM}$, $12–24\mathrm{h}$). The mRNA level ($12\mathrm{h}$) and protein expression ($24\mathrm{h}$) of occludin and claudin-1 were measured ($n=3\text{\hspace{0.17em} wells}/\text{group}$). Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as the housekeeping gene. (D) Fluorescence microscopy of occludin and claudin-1. The cells were treated with ${\text{AlCl}}_3$ ($2\text{\hspace{0.17em} mM}$, $24\mathrm{h}$). The images shown are representatives of three independent experiments. The values represent the $\text{mean}\pm \text{SEM}$ ($n=3$); *$p<0.05$, **$p<0.01$, and ***$p<0.001$ indicate a significant difference vs. the control (PBS). Note: PBS, phosphate buffered saline; SEM, standard error of the mean.