Clinically approved CFTR modulators rescue Nrf2 dysfunction in cystic fibrosis airway epithelia
Dana C. Borcherding, … , Scott M. Plafker, Assem G. Ziady
Dana C. Borcherding, … , Scott M. Plafker, Assem G. Ziady
Published August 1, 2019; First published May 30, 2019
Citation Information: J Clin Invest. 2019;129(8):3448-3463. https://doi.org/10.1172/JCI96273.
View: Text | PDF
Categories: Research Article Pulmonology

Clinically approved CFTR modulators rescue Nrf2 dysfunction in cystic fibrosis airway epithelia

Abstract

Cystic fibrosis (CF) is a multiorgan progressive genetic disease caused by loss of functional cystic fibrosis transmembrane conductance regulator (CFTR) channel. Previously, we identified a significant dysfunction in CF cells and model mice of the transcription factor nuclear factor E2–related factor-2 (Nrf2), a major regulator of redox balance and inflammatory signaling. Here we report that the approved F508del CFTR correctors VX809 and VX661 recover diminished Nrf2 function and colocalization with CFTR in CF human primary bronchial epithelia by proximity ligation assay, immunoprecipitation, and immunofluorescence, concordant with CFTR correction. F508del CFTR correctors induced Nrf2 nuclear translocation, Nrf2-dependent luciferase activity, and transcriptional activation of target genes. Rescue of Nrf2 function by VX809/VX661 was dependent on significant correction of F508del and was blocked by inhibition of corrected channel function, or high-level shRNA knockdown of CFTR or F508del CFTR. Mechanistically, F508del CFTR modulation restored Nrf2 phosphorylation and its interaction with the coactivator CREB-binding protein (CBP). Our findings demonstrate that sufficient modulation of F508del CFTR function corrects Nrf2 dysfunction in CF.

Authors

Dana C. Borcherding, Matthew E. Siefert, Songbai Lin, John Brewington, Hesham Sadek, John P. Clancy, Scott M. Plafker, Assem G. Ziady

×

Figure 6

Functional inhibition of CFTR reverses VX809-induced expression of Nrf2 target genes.

Options: View larger image (or click on image) Download as PowerPoint
Functional inhibition of CFTR reverses VX809-induced expression of Nrf2 ...
NhBE and CFhBE cells were treated with DMSO control, 1–10 μM VX809, or 30 nM CDDO, a Nrf2 activator, with or without 20 μM CFTRinh-172 for 48 or 72 hours. Gene expression of Nrf2-activated genes, GCLC (A), HMOX1 (B), and NQO1 (C), was determined by real-time qPCR. Gene expression is expressed as fold changes versus control cells (DMSO control or CFTRinh-172 alone), and was calculated from cycle threshold and normalization to the control gene, 18S rRNA. For 48-hour experiments (3 independent experiments from 3 patient donors each for non-CF and CF cells) and 72-hour experiments (7 independent experiments from 4 CF and 4 non-CF donors with 3 replicates per treatment per donor) and for 72-hour CDDO experiments (3 independent experiments from 4 CF and 4 non-CF donors with 3 replicates per treatment per donor), data are expressed as box-and-whisker plots. Horizontal bars indicate the median, box borders indicate 25th and 75th percentiles, and whiskers indicate 5th and 95th percentiles. *P < 0.05, **P < 0.01, ***P < 0.001 by mixed-effects ANOVA with Dunnett’s multiple-comparisons test.