Targeting HuR-Vav3 mRNA interaction prevents Pseudomonas aeruginosa adhesion to the cystic fibrosis airway epithelium
Mehdi Badaoui, Cyril Sobolewski, Alexandre Luscher, Marc Bacchetta, Thilo Köhler, Christian van Delden, Michelangelo Foti, Marc Chanson
Mehdi Badaoui, Cyril Sobolewski, Alexandre Luscher, Marc Bacchetta, Thilo Köhler, Christian van Delden, Michelangelo Foti, Marc Chanson
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Research Article Cell biology Infectious disease

Targeting HuR-Vav3 mRNA interaction prevents Pseudomonas aeruginosa adhesion to the cystic fibrosis airway epithelium

Abstract

Cystic fibrosis (CF) is characterized by chronic bacterial infections leading to progressive bronchiectasis and respiratory failure. Pseudomonas aeruginosa (Pa) is the predominant opportunistic pathogen infecting the CF airways. The guanine nucleotide exchange factor Vav3 plays a critical role in Pa adhesion to the CF airways by inducing luminal fibronectin deposition that favors bacteria trapping. Here we report that Vav3 overexpression in CF is caused by upregulation of the mRNA-stabilizing protein HuR. We found that HuR accumulates in the cytoplasm of CF airway epithelial cells and that it binds to and stabilizes Vav3 mRNA. Interestingly, disruption of the HuR-Vav3 mRNA interaction improved the CF epithelial integrity, inhibited the formation of the fibronectin-made bacterial docking platforms, and prevented Pa adhesion to the CF airway epithelium. These findings indicate that targeting HuR represents a promising antiadhesive approach in CF that can prevent initial stages of Pa infection in a context of emergence of multidrug-resistant pathogens.

Authors

Mehdi Badaoui, Cyril Sobolewski, Alexandre Luscher, Marc Bacchetta, Thilo Köhler, Christian van Delden, Michelangelo Foti, Marc Chanson

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Figure 2

CFTR knockdown in Calu-3 cells induces HuR overexpression.

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CFTR knockdown in Calu-3 cells induces HuR overexpression. (A and B) Qua...
(A and B) Quantification of the relative mRNA expression of HuR (A) and TTP (B) by qPCR in CFTR KD cells versus CTL Calu-3 cells. 18s served as an internal control. n = 5 in each group for HuR, and n = 3 in each group for TTP. Unpaired 2-tailed Student’s t test, *P < 0.05. (C) Representative Western blot showing HuR expression in CFTR KD cells versus CTL Calu-3 cells. GAPDH served as an internal control. Representative blots are shown on the left panels, and the quantification is shown on the right panel. n = 4 in each group. Mann-Whitney U test, *P < 0.05. (D) Representative confocal images of HuR (red) immunostaining in monolayer cultures of CFTR KD cells versus CTL Calu-3 cells. Nuclei are shown in blue. (E) Confocal microscopy analysis of HuR (red) localization in polarized CFTR KD cells versus CTL Calu-3 cells at ALI. Right panels show top view of representative images from 3D reconstruction of Z stack data. Scale bars: 20 μm.