Related Experiment Video
Updated: Jun 29, 2026

Imaging Approaches to Assessments of Toxicological Oxidative Stress Using Genetically-encoded Fluorogenic Sensors
Published on: February 7, 2018
Oxidative stress caused by pyocyanin impairs CFTR Cl(-) transport in human bronchial epithelial cells
Christian Schwarzer1, Horst Fischer, Eun-Jin Kim
1Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA.
Abstract:
Pyocyanin (N-methyl-1-hydroxyphenazine), a redox-active virulence factor produced by the human pathogen Pseudomonas aeruginosa, is known to compromise mucociliary clearance. Exposure of human bronchial epithelial cells to pyocyanin increased the rate of cellular release of H(2)O(2) threefold above the endogenous H(2)O(2) production. Real-time measurements of the redox potential of the cytosolic compartment using the redox sensor roGFP1 showed that pyocyanin (100 microM) oxidized the cytosol from a resting value of -318+/-5 mV by 48.0+/-4.6 mV within 2 h; a comparable oxidation was induced by 100 microM H(2)O(2). Whereas resting Cl(-) secretion was slightly activated by pyocyanin (to 10% of maximal currents), forskolin-stimulated Cl(-) secretion was inhibited by 86%. The decline was linearly related to the cytosolic redox potential (1.8% inhibition/mV oxidation). Cystic fibrosis bronchial epithelial cells homozygous for DeltaF508 CFTR failed to secrete Cl(-) in response to pyocyanin or H(2)O(2), indicating that these oxidants specifically target the CFTR and not other Cl(-) conductances. Treatment with pyocyanin also decreased total cellular glutathione levels to 62% and cellular ATP levels to 46% after 24 h. We conclude that pyocyanin is a key factor that redox cycles in the cytosol, generates H(2)O(2), depletes glutathione and ATP, and impairs CFTR function in Pseudomonas-infected lungs.
More Related Videos
08:00Generation of Human Nasal Epithelial Cell Spheroids for Individualized Cystic Fibrosis Transmembrane Conductance Regulator Study
Published on: April 11, 2018
15:12Purification of the Cystic Fibrosis Transmembrane Conductance Regulator Protein Expressed in Saccharomyces cerevisiae
Published on: May 10, 2014
Related Concept Videos
Cystic Fibrosis: Pathogenesis
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation, but...
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Cystic Fibrosis: Management
Sinus disease and chronic sinusitis...
The Electron Transport Chain
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q in...
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
Electron Transport Chain: Complex III and IV