Figure 5.

TNF-α and IL-1β require a functional NF-κB complex to regulate CFTR. (A) CFTR mRNA concentrations were ascertained according to quantitative RT-PCR in Calu-3–polarized cultures, 8 hours after cytokine stimulation (n = 4, four replicates each). Cultures were transduced 3 days before cytokine stimulation. (B) CFTR immunoblot in pretransduced Calu-3 cells, 8 hours after PBS or TNF-α or IL-1β stimulation. Densitometry and relative fold change of CFTR protein abundance (n = 4, three replicates each) were determined. Immunoblotting was rearranged to suit the presentation order. Changes in (C) conductance (G_t) and (D) transepithelial current (I_t) were measured 8 hours after the indicated treatments in Calu-3–polarized cultures (n = 4). Basal transepithelial resistance range, 318–479 ohms · cm²; and I_t range, 32–58 microamperes · cm². All error bars indicate the mean ± SE. Statistical significance was determined by the Student t test. *P < 0.05, **P < 0.01, and ***P < 0.001. Ad-e, empty adenovirus; dnIκB-α, dominant-negative IκB-α; NS, not statistically significant.