FIGURE 3.

CaCC human airway epithelial cells. A, stimulation of human airway epithelial cells (16HBE) with 100 μm ATP activates a Cl⁻ current in a whole cell patch clamp experiment. Activation was inhibited by 100 μm DIDS. B, summary of experiments shown in A. nS, nanosiemens. C, I/V relationship of the whole cell currents before and after exposure to ATP and ATP/DIDS. D, summary of the experiments in which 16HBE cells were incubated with BEST1 siRNA (RNAi) to knock down BEST1 expression. Transfection with scrambled RNA (scrbled) served as a control. Experiments were performed in the presence of the K⁺ channel blockers Ba²⁺ (5 mm) and tetraethylammonium (TEA; 10 mm) to exclude K⁺ conductances. The asterisks indicate significant difference compared with the control (paired Student's t test). The number signs indicate significant difference compared with siRNA (unpaired Student's t test). The number of experiments is indicated in parentheses. E, Western blot of human BEST1 and actin in siRNA-treated and control cells.