Antioxidants preserve macrophage phagocytosis of Pseudomonas aeruginosa during hyperoxia.
Free Radic Biol Med
; 42(9): 1338-49, 2007 May 01.
Article
in En
| MEDLINE
| ID: mdl-17395007
ABSTRACT
Pseudomonas. aeruginosa (PA) is a leading cause of nosocomial pneumonia in patients receiving mechanical ventilation with hyperoxia. Exposure to supraphysiological concentrations of reactive oxygen species during hyperoxia may result in macrophage damage that reduces their ability to phagocytose PA. We tested this hypothesis in cultured macrophage-like RAW 264.7 cells and alveolar macrophages from mice exposed to hyperoxia. Exposure to hyperoxia induced a similarly impaired phagocytosis of both the mucoid and the nonmucoid forms of PA in alveolar macrophages and RAW cells. Compromised PA phagocytosis was associated with cytoskeleton disorganization and actin oxidation in hyperoxic macrophages. To test whether moderate concentrations of O(2) limit the loss of phagocytic function induced by > or =95% O(2), mice and RAW cells were exposed to 65% O(2). Interestingly, although the resulting lung injury/cell proliferation was not significant, exposure to 65% O(2) resulted in a marked reduction in PA phagocytosis that was comparable to that of > or =95% O(2). Treatment with antioxidants, even post hyperoxic exposure, preserved actin cytoskeleton organization and phagocytosis of PA. These data suggest that hyperoxia reduces macrophage phagocytosis through effects on actin functions which can be preserved by antioxidant treatment. In addition, administration of moderate rather than higher concentrations of O2 does not improve macrophage phagocytosis of PA.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phagocytosis
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Pseudomonas aeruginosa
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Macrophages, Alveolar
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Hyperoxia
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Macrophages
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Antioxidants
Limits:
Animals
Language:
En
Journal:
Free Radic Biol Med
Journal subject:
BIOQUIMICA
/
MEDICINA
Year:
2007
Document type:
Article
Affiliation country:
United States
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA