title: Role of NOS2 in pulmonary injury and repair in response to bleomycin.
abstract: Nitric oxide (NO) is derived from multiple isoforms of the Nitric Oxide Synthases (NOSs) within the lung for a variety of functions; however, NOS2-derived nitrogen oxides seem to play an important role in inflammatory regulation. In this study, we investigate the role of NOS2 in pulmonary inflammation/fibrosis in response to intratracheal bleomycin instillation (ITB) and to determine if these effects are related to macrophage phenotype. Systemic NOS2 inhibition was achieved by administration of 1400W, a specific and potent NOS2 inhibitor, via osmotic pump starting six days prior to ITB. 1400W administration attenuated lung inflammation, decreased chemotactic activity of the broncheoalveolar lavage (BAL), and reduced BAL cell count and nitrogen oxide production. S-nitrosylated SP-D (SNO-SP-D), which has a pro-inflammatory function, was formed in response to ITB; but this formation, as well as structural disruption of SP-D, was inhibited by 1400W. mRNA levels of IL-1β, CCL2 and Ptgs2 were decreased by 1400W treatment. In contrast, expression of genes associated with alternate macrophage activation and fibrosis Fizz1, TGF-β and Ym-1 was not changed by 1400W. Similar to the effects of 1400W, NOS2-/- mice displayed an attenuated inflammatory response to ITB (day 3 and day 8 post-instillation). The DNA-binding activity of NF-κB was attenuated in NOS2-/- mice; in addition, expression of alternate activation genes (Fizz1, Ym-1, Gal3, Arg1) was increased. This shift towards an increase in alternate activation was confirmed by western blot for Fizz-1 and Gal-3 that show persistent up-regulation 15 days after ITB. In contrast arginase, which is increased in expression at 8 days post ITB in NOS2-/-, resolves by day 15. These data suggest that NOS2, while critical to the development of the acute inflammatory response to injury, is also necessary to control the late phase response to ITB.
authors.affiliation: Department of Pharmacology & Toxicology, Rutgers, the State University of New Jersey, Piscataway, NJ, USA.
authors.forename: Changjiang
authors.initials: C
authors.lastname: Guo
authors.affiliation: Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Atochina-Vasserman
authors.affiliation: Department of Pharmacology & Toxicology, Rutgers, the State University of New Jersey, Piscataway, NJ, USA.
authors.forename: Helen
authors.initials: H
authors.lastname: Abramova
authors.affiliation: Department of Pharmacology & Toxicology, Rutgers, the State University of New Jersey, Piscataway, NJ, USA.
authors.forename: Blessy
authors.initials: B
authors.lastname: George
authors.affiliation: Department of Molecular Genetics, Cleveland Clinic, Lerner Research Institute, Cleveland, OH, USA.
authors.forename: Veleeparambil
authors.initials: V
authors.lastname: Manoj
authors.affiliation: Department of Pharmacology & Toxicology, Rutgers, the State University of New Jersey, Piscataway, NJ, USA.
authors.forename: Pamela
authors.initials: P
authors.lastname: Scott
authors.affiliation: Department of Pharmacology & Toxicology, Rutgers, the State University of New Jersey, Piscataway, NJ, USA. Electronic address: gow@rci.rutgers.edu.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gow
mesh_terms: D000818:Animals; D001761:Bleomycin; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008168:Lung / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D055370:Lung Injury / Q000139:chemically induced / Q000201:enzymology* / Q000276:immunology; D008262:Macrophage Activation; D008810:Mice, Inbred C57BL; D052247:Nitric Oxide Synthase Type II / Q000502:physiology*; D012038:Regeneration; D059467:Transcriptome
chemical_list: D008070:Lipopolysaccharides; D001761:Bleomycin; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse
keywords: Bleomycin; NOS2 inhibitor; Pulmonary inflammation; S-nitrosylation; Surfactant protein-D