title: Silica, hyaluronate, and alveolar macrophage functional differentiation.
abstract: BACKGROUND
  Silicosis is mediated by macrophages, their soluble mediators, and extracellular matrix molecules. In this study, we investigated the effects of silica and/or hyaluronate (HA) on several alveolar macrophage responses.
  
  
  METHODS
  We evaluated glycosaminoglycan (GAG) production by radiolabeled precursors, nitric oxide (NO) release by its oxidation product, phagocytic activity by Candida albicans internalization, and the secretion of two fibrogenic cytokines, tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta, by specific assays.
  
  
  RESULTS
  Silica significantly reduced GAG secretion, particularly HA secretion. Alone, it decreased Candida uptake; associated with HA, it enhanced the reduction. Silica and Candida reduced NO release, which was not significantly affected when silica- or Candida-exposed cells were also treated with HA. TNF-alpha and TGF-beta activities were stimulated by silica but reduced by HA.
  
  
  CONCLUSIONS
  The results suggest that silica and HA modify alveolar macrophage functional differentiation. Silica- and HA-induced modifications of the microenvironment could determine whether the response proceeds toward healing and repair or toward lung chronic pathology.
authors.affiliation: Histology Section, Faculty of Medicine, University of Perugia, Italy. bodo@unipg.it
authors.forename: Maria
authors.initials: M
authors.lastname: Bodo
authors.forename: Silvia
authors.initials: S
authors.lastname: Bellocchio
authors.forename: Catia
authors.initials: C
authors.lastname: Bellucci
authors.forename: Stefania
authors.initials: S
authors.lastname: Balloni
authors.forename: Donatella
authors.initials: D
authors.lastname: Pietrella
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sbaraglia
authors.forename: Giacomo
authors.initials: G
authors.lastname: Muzi
authors.forename: Cinzia
authors.initials: C
authors.lastname: Lilli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Lumare
authors.forename: Marco
authors.initials: M
authors.lastname: Dell'Omo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Abbritti
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D006025:Glycosaminoglycans / Q000378:metabolism; D006820:Hyaluronic Acid / Q000494:pharmacology*; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D051381:Rats; D012822:Silicon Dioxide / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D004338:Drug Combinations; D006025:Glycosaminoglycans; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D012822:Silicon Dioxide; D006820:Hyaluronic Acid