Role of nicotinamide adenine dinucleotide phosphate-reduced oxidase proteins in Pseudomonas aeruginosa-induced lung inflammation and permeability.

Abstract

Earlier studies indicated a role for reactive oxygen species (ROS) in host defense against Pseudomonas aeruginosa infection. However, the role of nicotinamide adenine dinucleotide phosphate-reduced (NADPH) oxidase (NOX) proteins and the mechanism of activation for NADPH oxidase in P. aeruginosa infection are not well-defined. Here, we investigated the role of NOX2 and NOX4 proteins in P. aeruginosa infection, ROS generation, and endothelial barrier function in murine lungs and in human lung microvascular endothelial cells (HLMVECs). Airway instillation of P. aeruginosa strain 103 (PA103) significantly increased ROS concentrations in bronchial alveolar lavage (BAL) fluid, along with the expression of NOX2 and NOX4, but not NOX1 and NOX3, in lung tissue. In addition, PA103-infected HLMVECs revealed elevated concentrations of ROS, NOX2, and NOX4. In murine lungs and HLMVECs, PA103 induced the NF-κB pathway, and its inhibition blocked PA103-dependent NOX2 and NOX4 expression. Barrier function analysis showed that heat-killed PA103 induced endothelial permeability in a dose-dependent manner, which was attenuated by treatment with small interfering (si)RNA specific for NOX4, but not NOX2. Furthermore, the knockdown of NOX4, but not NOX2, with siRNA reduced PA103-mediated apoptosis in HLMVECs. In vivo, the down-regulation of NOX4 with NOX4 siRNA attenuated PA103-induced lung vascular permeability. The deletion of NOX2 in mice exerted no effect on permeability, but offered significant resistance to P. aeruginosa-induced lung inflammation. These data show that P. aeruginosa lung infection up-regulates NOX2 and NOX4 expression and ROS generation, which play distinct roles in regulating lung inflammation, apoptosis, and permeability.

• Authors: Panfeng Fu, Vijay Mohan, Syed Mansoor, Chinnaswamy Tiruppathi, Ruxana T Sadikot, Viswanathan Natarajan
• Journal: American journal of respiratory cell and molecular biology (Am J Respir Cell Mol Biol) Vol. 48 Issue 4 Pg. 477-88 (Apr 2013) ISSN: 1535-4989 [Electronic] United States
• PMID: 23306835 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Membrane Glycoproteins
• Reactive Oxygen Species
• NADP
• CYBB protein, human
• Cybb protein, mouse
• NADPH Oxidase 2
• NADPH Oxidase 4
• NADPH Oxidases
• NOX4 protein, human
• Nox4 protein, mouse

Topics

• Animals
• Blood-Air Barrier (enzymology, pathology)
• Capillary Permeability
• Cells, Cultured
• Gene Expression Regulation, Enzymologic (genetics)
• Humans
• Membrane Glycoproteins (biosynthesis, genetics)
• Mice
• Mice, Knockout
• NADP (genetics, metabolism)
• NADPH Oxidase 2
• NADPH Oxidase 4
• NADPH Oxidases (biosynthesis, genetics)
• Pneumonia, Bacterial (enzymology, genetics, pathology)
• Pseudomonas Infections (enzymology, genetics, pathology)
• Pseudomonas aeruginosa
• Reactive Oxygen Species (metabolism)