FIGURE 1.

Single and repeated Caco-2/HT29-MTX pro-inflammatory induction after days 14 and 21. TEER (A,B), permeability (C), and IL-8 release (D,F) in a differentiated Caco-2/HT29-MTX coculture basolaterally treated with different concentrations of TNFα (0–100 ng/ml) on day 21 (single) or days 14 and 21 (repeated). Each inflammatory stimulus (red dashed line) was left for up to 24 h; this was followed by a recovery period of up to 120 h without an inflammatory inducer. TEER values are represented in percentage; zero-hour treatment was used as reference (100%). Permeability is expressed as fold change over the untreated control (CTL). Data are presented as the average of three technical replicates with the corresponding standard deviations (n = 1; m > 3). On the day at the end of the simulation and the last day recorded, statistical differences between the control without TNFα and each of the three concentrations of TNFα were determined by a two-tailed t-test, *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ns, p > 0.05. Equivalence comparisons and linear regression analysis are provided in Supplementary Tables S1 and S2. Abbreviations: TEER, transepithelial electrical resistance; TNF, tumor necrosis factor; CTL, control.