Comparison of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) and Ciliary Beat Frequency Activation by the CFTR Modulators Genistein, VRT-532, and UC_CF-152 in Primary Sinonasal Epithelial Cultures

Abstract

IMPORTANCE Pharmacologic activation of mucociliary clearance (MCC) represents an emerging therapeutic strategy for patients with chronic rhinosinusitis, even in the absence of congenital mutations of the CFTR gene. Drug discovery efforts have identified small molecules that activate the cystic fibrosis transmembrane conductance regulator (CFTR), including potentiators under development for treatment of cystic fibrosis. OBJECTIVE To evaluate the properties of CFTR modulators and their effects on ciliary beat frequency (CBF) in human sinonasal epithelium (HSNE). DESIGN Primary HSNE cultures (wild type and F508del/F508del) were used to compare stimulation of CFTR-mediated Cl− conductance and CBF by the CFTR modulators genistein, VRT-532, and UCCF-152. MAIN OUTCOMES AND MEASURES Increase in CFTR-dependent anion transport and CBF. RESULTS HSNE cultures were analyzed using pharmacologic manipulation of ion transport (change in short-circuit current [ΔISC]) and high-speed digital imaging (CBF). Activation of CFTR-dependent anion transport was significantly different among agonists (P < .001), with genistein exerting the greatest effect (mean [SD] ΔISC, genistein, 23.1 [1.8] µA/cm2 > VRT-532, 8.1 [1.0] µA/cm2 > UCCF-152, 3.4 [1.4] µA/cm2 > control, 0.7 [0.2] µA/cm2; Tukey-Kramer P < .05) in the absence of forskolin. Genistein and UCCF-152 augmented CBF (under submerged conditions) significantly better (Tukey-Kramer P < .05) than cells treated with VRT-532 or dimethyl sulfoxide vehicle control (mean [SD] fold change over baseline, genistein, 1.63 [0.06]; UCCF-152, 1.56 [0.06]; VRT-532, 1.38 [0.08]; control, 1.27 [0.02]). Activation of CBF was blunted in F508del/F508del HSNE cultures. CONCLUSIONS AND RELEVANCE The degree of CBF stimulation was not dependent on the magnitude of Cl− secretion, suggesting that different mechanisms of action may underlie MCC activation by these small molecule potentiators. Agents that activate both CFTR-dependent ISC and CBF are particularly attractive as therapeutics because they may address 2 independent pathways that contribute to deficient MCC in chronic rhinosinusitis.

Resveratrol and ivacaftor are additive G551D CFTR‐channel potentiators: therapeutic implications for cystic fibrosis sinus disease

“…Stimulation of CFTR-mediated I SC with CFTR potentiators was typically better with primary HSNE as a percentage of overall forskolin-stimulated I SC . 25 Maximal Cl − secretion was augmented with both agents (resveratrol+ivacaftor, 32.2+/−1.17 vs. resveratrol, 10.73+/−0.84 vs. ivacaftor, 21.29+/−0.85 vs. DMSO, 3.88+/−0.85; p<0.001) to levels consistent with what is detected in non-CF HSNE. 26–28 …”

Assessment of acquired mucociliary clearance defects using micro‐optical coherence tomography

“…A high‐speed monochromatic digital video camera (Model A602f‐2; Basler AG, Ahrensburg, Germany) was used to record data at a sampling rate of 100 frames/s. Images were analyzed with Sisson‐Ammons Video Analysis (SAVA, version 2.0.8 W) system . Using the inverted microscope, large regions of beating cilia were identified within HSNE ALI cultures for each experiment.…”

Medical and Surgical Advancements in the Management of Cystic Fibrosis Chronic Rhinosinusitis

“…Importantly, CFTR modulators are also beginning to make their way into clinical studies and represent potential future therapies for mucociliary clearance defects in patients with non-CF CRS. 44,45,106–116 …”