title: Dual acute proinflammatory and antifibrotic pulmonary effects of short palate, lung, and nasal epithelium clone-1 after exposure to carbon nanotubes.
abstract: Carbon nanotubes (CNTs; allotropes of carbon with a cylindrical nanostructure) have emerged as one of the most commonly used types of nanomaterials, with numerous applications in industry and biomedicine. However, the inhalation of CNTs has been shown to elicit pulmonary toxicity, accompanied by a robust inflammatory response with an early-onset fibrotic phase. Epithelial host-defense proteins represent an important component of the pulmonary innate immune response to foreign inhalants such as particles and bacteria. The short palate, lung, and nasal epithelium clone-1 (SPLUNC1) protein, a member of the bactericidal/permeability-increasing-fold (BPIF)-containing protein family, is a 25-kD secretory protein that is expressed in nasal, oropharyngeal, and lung epithelia, and has been shown to have multiple functions, including antimicrobial and chemotactic activities, as well as surfactant properties. This study sought to assess the importance of SPLUNC1-mediated pulmonary responses in airway epithelial secretions, and to explore the biological relevance of SPLUNC1 to inhaled particles in a single-walled carbon nanotube (SWCNT) model. Using Scgb1a1-hSPLUNC1 transgenic mice, we observed that SPLUNC1 significantly modified host inflammatory responses by increasing leukocyte recruitment and enhancing phagocytic activity. Furthermore, we found that transgenic mice were more susceptible to SWCNT exposure at the acute phase, but showed resistance against lung fibrogenesis through pathological changes in the long term. The binding of SPLUNC1 also attenuated SWCNT-induced TNF-α secretion by RAW 264.7 macrophages. Taken together, our data indicate that SPLUNC1 is an important component of mucosal innate immune defense against pulmonary inhaled particles.
authors.affiliation: 1 Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Y Peter
authors.initials: YP
authors.lastname: Di
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Tkach
authors.forename: Naveena
authors.initials: N
authors.lastname: Yanamala
authors.forename: Shyla
authors.initials: S
authors.lastname: Stanley
authors.forename: Shengli
authors.initials: S
authors.lastname: Gao
authors.forename: Michael R
authors.initials: MR
authors.lastname: Shurin
authors.forename: Elena R
authors.initials: ER
authors.lastname: Kisin
authors.forename: Valerian E
authors.initials: VE
authors.lastname: Kagan
authors.forename: Anna
authors.initials: A
authors.lastname: Shvedova
mesh_terms: D000818:Animals; D002460:Cell Line; D002633:Chemotaxis; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D007113:Immunity, Innate; D018928:Immunity, Mucosal; D018836:Inflammation Mediators / Q000378:metabolism; D019570:Inhalation Exposure; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008168:Lung / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D016676:Macrophages, Alveolar / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D037742:Nanotubes, Carbon / Q000633:toxicity*; D010587:Phagocytosis; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011014:Pneumonia / Q000139:chemically induced / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C485599:BPIFA1 protein, human; D006023:Glycoproteins; D018836:Inflammation Mediators; D037742:Nanotubes, Carbon; D010750:Phosphoproteins; D014409:Tumor Necrosis Factor-alpha