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 H2O2 threefold above the endogenous H2O2 production. Real-time measurements of the redox potential of the cytosolic compartment using the redox sensor roGFP1 showed that pyocyanin (100 μM) 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 μM H2O2. 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 ΔF508 CFTR failed to secrete Cl- in response to pyocyanin or H2O2, 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 H2O2, depletes glutathione and ATP, and impairs CFTR function in Pseudomonas-infected lungs.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1653-1662 |
| Number of pages | 10 |
| Journal | Free Radical Biology and Medicine |
| Volume | 45 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 15 2008 |
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Keywords
- CFTR
- Chloride ion transport
- Cystic fibrosis
- Free radicals
- Glutathione
- Hydrogen peroxide
- Intracellular redox potential
- Oxidative stress
- Pseudomonas aeruginosa
- Pyocyanin
ASJC Scopus subject areas
- Biochemistry
- Physiology (medical)
Cite this
Oxidative stress caused by pyocyanin impairs CFTR Cl- transport in human bronchial epithelial cells. / Schwarzer, Christian; Fischer, Horst; Kim, Eun Jin; Barber, Katharine J.; Mills, Aaron D.; Kurth, Mark J.; Gruenert, Dieter C.; Suh, Jung H.; Machen, Terry E.; Illek, Beate.
In: Free Radical Biology and Medicine, Vol. 45, No. 12, 15.12.2008, p. 1653-1662.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Oxidative stress caused by pyocyanin impairs CFTR Cl- transport in human bronchial epithelial cells
AU - Schwarzer, Christian
AU - Fischer, Horst
AU - Kim, Eun Jin
AU - Barber, Katharine J.
AU - Mills, Aaron D.
AU - Kurth, Mark J.
AU - Gruenert, Dieter C.
AU - Suh, Jung H.
AU - Machen, Terry E.
AU - Illek, Beate
PY - 2008/12/15
Y1 - 2008/12/15
N2 - 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 H2O2 threefold above the endogenous H2O2 production. Real-time measurements of the redox potential of the cytosolic compartment using the redox sensor roGFP1 showed that pyocyanin (100 μM) 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 μM H2O2. 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 ΔF508 CFTR failed to secrete Cl- in response to pyocyanin or H2O2, 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 H2O2, depletes glutathione and ATP, and impairs CFTR function in Pseudomonas-infected lungs.
AB - 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 H2O2 threefold above the endogenous H2O2 production. Real-time measurements of the redox potential of the cytosolic compartment using the redox sensor roGFP1 showed that pyocyanin (100 μM) 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 μM H2O2. 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 ΔF508 CFTR failed to secrete Cl- in response to pyocyanin or H2O2, 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 H2O2, depletes glutathione and ATP, and impairs CFTR function in Pseudomonas-infected lungs.
KW - CFTR
KW - Chloride ion transport
KW - Cystic fibrosis
KW - Free radicals
KW - Glutathione
KW - Hydrogen peroxide
KW - Intracellular redox potential
KW - Oxidative stress
KW - Pseudomonas aeruginosa
KW - Pyocyanin
UR - http://www.scopus.com/inward/record.url?scp=56349106857&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=56349106857&partnerID=8YFLogxK
U2 - 10.1016/j.freeradbiomed.2008.09.011
DO - 10.1016/j.freeradbiomed.2008.09.011
M3 - Article
VL - 45
SP - 1653
EP - 1662
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
SN - 0891-5849
IS - 12
ER -