Multiple contributing roles for NOS2 in LPS-induced acute airway inflammation in mice.
Acute lung inflammation and injury were induced by intranasal instillation of lipopolysaccharide (LPS) in normal and type 2 nitric oxide synthase (NOS2)-deficient (NOS2-/-) C57BL/6 mice. LPS-induced increases in extravasated airway neutrophils and in lung lavage fluid of TNF-alpha and macrophage inflammatory protein-2 were markedly lower in NOS2-/- than in wild-type mice, indicating that NOS2-derived nitric oxide (NO.) participates in inflammatory cytokine production and neutrophil recruitment. Instillation of LPS also increased total lung lavage protein and induced matrix metalloproteinase-9 and mucin 5AC, as indexes of lung epithelial injury and/or mucus hyperplasia, and increased tyrosine nitration of lung lavage proteins, a marker of oxidative injury. All these responses were less pronounced in NOS2-/- than in wild-type mice. Inhibition of NOS activity also suppressed production of TNF-alpha and macrophage inflammatory protein-2 by LPS-stimulated mouse alveolar MH-S macrophages, and this was restored by NO. donors, illustrating involvement of NO. in macrophage cytokine signaling. Oligonucleotide microarray (GeneChip) analysis of global lung gene expression revealed that LPS inhalation induced a range of transcripts encoding proinflammatory cytokines and chemokines, stress-inducible factors, and other extracellular factors and suppressed mRNAs encoding certain cytoskeletal proteins and signaling proteins, responses that were generally attenuated in NOS2-/- mice. Comparison of both mouse strains revealed altered expression of several cytoskeletal proteins, cell surface proteins, and signaling proteins in NOS2-/- mice, changes that may partly explain the reduced responsiveness to LPS. Collectively, our results suggest that NOS2 participates in the acute inflammatory response to LPS by multiple mechanisms: involvement in proinflammatory cytokine signaling and alteration of the expression of various genes that affect inflammatory-immune responses to LPS.
Okamoto
Tatsuya
T
Department of Internal Medicine, University of California, Davis, 95616, USA.
Gohil
Kishorchandra
K
Finkelstein
Erik I
EI
Bove
Peter
P
Akaike
Takaaki
T
van der Vliet
Albert
A
D000208:Acute Disease; D000281:Administration, Intranasal; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D016000:Cluster Analysis; D016207:Cytokines / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology; D020780:Matrix Metalloproteinase 9 / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D055271:Mucin 5AC; D009077:Mucins / Q000235:genetics; D009504:Neutrophils / Q000276:immunology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D009584:Nitrogen / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011014:Pneumonia / Q000276:immunology* / Q000378:metabolism / Q000503:physiopathology*; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology
D016207:Cytokines; D008070:Lipopolysaccharides; C524679:Muc5ac protein, mouse; D055271:Mucin 5AC; D009077:Mucins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D020780:Matrix Metalloproteinase 9; D009584:Nitrogen