Resveratrol hydrates ASL.

<p>Resveratrol significantly increased ASL depth (in μm) in murine nasal septal epithelial cultures (8.08±1.68 vs. 6.11±0.47, control, *p<0.05). Addition of CFTR(inh)-172 inhibited resveratrol-dependent ASL accumulation (3.54±0.34, **p<0.001) (A). Confocal images demonstrate treatment effect from stimulation of apical Cl^- secretion and enhanced CFTR channel Po (Red-ASL; Green-Cell marker) (B). </p

Open channel probability.

<p>Open probability (NPo/N where <i>N</i> represents channel number) was calculated from single channel recordings under control conditions and after perfusion with 100 µM resveratrol obtained in similar experiments to those displayed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081589#pone-0081589-g004" target="_blank">Figure 4</a>. Data are presented as mean ± SEM. Data points were compared with control using paired Student's t test (*P<0.05).</p

CFTR channel activity in MNSE cells.

<p>Constitutively active CFTR channel currents were recorded from a cell attached patch from MNSE. Two discernable channels were observed. Dotted line represents closed state and numbers to the left indicate holding potential. A linear current-voltage relationship (IV curve – lower panel) was obtained from a cell attached patch containing spontaneously active CFTR. Channel conductance was ~8.0 pS. </p

Resveratrol is a robust activator of CFTR-mediated Cl^- secretion in primary sinonasal epithelial cell cultures from several mammalian species and immortalized CFBE cells.

<p>(A) Representative Ussing chamber tracings demonstrate pharmacologic manipulation of ion transport showing resveratrol activation of Cl^- transport in murine, human, and porcine sinonasal epithelial cell cultures. By convention, a positive deflection in the tracing (ΔI_SC) represents movement of anion in the serosal to mucosal direction. (B) Graphic representation of resveratrol (100 µM) stimulation vs. total stimulation [resveratrol (100 µM) + forskolin (20 uM)] for transepithelial Cl^- conductance in murine, human, and porcine primary nasal epithelial cultures. Significant stimulation (p<0.05) of Cl^- transport was demonstrated in primary sinonasal cultures as compared to untreated vehicle controls in all species. Total stimulation (addition of 20 µM forskolin) was also significantly greater than resveratrol alone (p<0.05). Resveratrol (as a percentage of total stimulation) consistently activated between 50 to 70% of total CFTR-mediated anion transport. (C) When compared to ivacaftor (10 µM) in human sinonasal epithelial cultures, resveratrol activates wild type CFTR-mediated anion transport to a similar degree. (D) Stimulation of wild type (WT) and temperature corrected (TC)-F508del CFTR was noted in the CFBE cell line. </p

Resveratrol stimulates single CFTR channel activity.

<p>Under non-phosphorylating conditions, application of resveratrol enhanced channel activity in both MNSE (upper tracing) and D060/HEK293 cells expressing exogenous WT CFTR (bottom tracing). Patches were excised and spontaneous channel function recorded at – Vcom = +50 mV. Activity was stimulated within seconds of application of 100 µM resveratrol. Similar enhancement was observed in doxycycline induced, CFTR-expressing D060 cells and abrogated by addition of CFTR(inh)172. Dotted lines indicate zero current level. </p

Resveratrol activates CFTR-mediated Cl^- secretion in human sinonasal mucosa <i>ex</i><i>vivo</i>.

<p>Representative Ussing chamber tracings of full thickness human sinonasal tissue explants demonstrating robust activation of CFTR-dependent Cl^- secretion with 100 µM resveratrol (A). Ussing chamber summary data evaluating paired sinus mucosal samples from 5 individuals, and demonstrating significant activation (p<0.05) of <i>ex </i><i>vivo</i> CFTR-dependent Cl^- transport (B). </p