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Updated: Dec 25, 2025
Pseudomonas aeruginosa Induced Lung Injury Model
Published on: October 29, 2014
α-Tocopherol Attenuates the Severity of Pseudomonas aeruginosa-induced Pneumonia
Brant M Wagener1,2, Naseem Anjum1, Cilina Evans1
1Department of Anesthesiology and Perioperative Medicine.
Abstract:
Pseudomonas aeruginosa is a lethal pathogen that causes high mortality and morbidity in immunocompromised and critically ill patients. The type III secretion system (T3SS) of P. aeruginosa mediates many of the adverse effects of infection with this pathogen, including increased lung permeability in a Toll-like receptor 4/RhoA/PAI-1 (plasminogen activator inhibitor-1)-dependent manner. α-Tocopherol has antiinflammatory properties that may make it a useful adjunct in treatment of this moribund infection. We measured transendothelial and transepithelial resistance, RhoA and PAI-1 activation, stress fiber formation, P. aeruginosa T3SS exoenzyme (ExoY) intoxication into host cells, and survival in a murine model of pneumonia in the presence of P. aeruginosa and pretreatment with α-tocopherol. We found that α-tocopherol alleviated P. aeruginosa-mediated alveolar endothelial and epithelial paracellular permeability by inhibiting RhoA, in part, via PAI-1 activation, and increased survival in a mouse model of P. aeruginosa pneumonia. Furthermore, we found that α-tocopherol decreased the activation of RhoA and PAI-1 by blocking the injection of T3SS exoenzymes into alveolar epithelial cells. P. aeruginosa is becoming increasingly antibiotic resistant. We provide evidence that α-tocopherol could be a useful therapeutic agent for individuals who are susceptible to infection with P. aeruginosa, such as those who are immunocompromised or critically ill.
Insights
Alpha-tocopherol, or vitamin E, reduces lung permeability and increases survival in mice infected with Pseudomonas aeruginosa. This vitamin E treatment inhibits the pathogen's type III secretion system (T3SS) virulence factor delivery.
Area of Science:
- Microbiology
- Immunology
- Pharmacology
Background:
- Pseudomonas aeruginosa is a dangerous pathogen causing severe illness and death, particularly in vulnerable patients.
- The type III secretion system (T3SS) of P. aeruginosa is a key factor in its pathogenicity, increasing lung permeability.
- Alpha-tocopherol (vitamin E) possesses anti-inflammatory properties with potential therapeutic benefits.
Purpose of the Study:
- To investigate the protective effects of alpha-tocopherol against P. aeruginosa infection.
- To determine if alpha-tocopherol can mitigate T3SS-mediated lung permeability and improve survival rates.
Main Methods:
- Experiments measured transendothelial/transepithelial resistance, RhoA/PAI-1 activation, and stress fiber formation.
- Assessed P. aeruginosa T3SS exoenzyme (ExoY) intoxication and survival in a murine pneumonia model.
- Evaluated the impact of alpha-tocopherol pretreatment on these parameters.
Main Results:
- Alpha-tocopherol reduced P. aeruginosa-induced alveolar permeability by inhibiting RhoA and PAI-1 activation.
- The treatment increased survival rates in a mouse model of P. aeruginosa pneumonia.
- Alpha-tocopherol blocked T3SS exoenzyme injection into host cells, decreasing RhoA and PAI-1 activation.
Conclusions:
- Alpha-tocopherol demonstrates therapeutic potential against P. aeruginosa infections.
- It alleviates lung barrier dysfunction and enhances survival by inhibiting T3SS activity.
- This suggests alpha-tocopherol could be a valuable adjunct therapy for immunocompromised and critically ill patients.
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