title: Azithromycin inhibits macrophage interleukin-1β production through inhibition of activator protein-1 in lipopolysaccharide-induced murine pulmonary neutrophilia.
abstract: Macrolide antibiotics, including azithromycin, also possess anti-inflammatory properties. However, the molecular mechanism(s) of activity as well as the target cells for their action have not been unambiguously identified as yet. In this study, the effects of azithromycin on lipopolysaccharide (LPS)-induced pulmonary neutrophilia were investigated in mice. Using immunohistochemistry, mRNA and specific protein assays, we confirmed that azithromycin ameliorates LPS-induced pulmonary neutrophilia by inhibiting interleukin-1β (IL-1β) expression and production selectively in alveolar macrophages as well as in LPS-stimulated J774.2 macrophage-derived cells in vitro. Inhibition by azithromycin of neutrophilia and IL-1β was accompanied by prevention of nuclear expression of activator protein-1 (AP-1) in both alveolar macrophages and J774.2 cells. The macrolide did not alter nuclear factor kappa B (NF-κB) or extracellular signal-regulated kinase 1/2 (ERK1/2) expression, activation or localization in LPS-stimulated lungs or in J774.2 cells. In conclusion, we have shown that inhibition of LPS-induced pulmonary neutrophilia and IL-1β concentrations in lung tissue following azithromycin treatment is mediated through effects on alveolar macrophages. In addition, we have shown for the first time, in an in vivo model, that azithromycin inhibits AP-1 activation in alveolar macrophages, an action confirmed on J774.2 cells in vitro.
authors.affiliation: GlaxoSmithKline Research Centre Zagreb Limited, Prilaz baruna Filipovića 29, HR-10000 Zagreb, Croatia. martina.bosnar@glpg.com
authors.forename: Martina
authors.initials: M
authors.lastname: Bosnar
authors.forename: Snježana
authors.initials: S
authors.lastname: Čužić
authors.forename: Berislav
authors.initials: B
authors.lastname: Bošnjak
authors.forename: Krunoslav
authors.initials: K
authors.lastname: Nujić
authors.forename: Gabrijela
authors.initials: G
authors.lastname: Ergović
authors.forename: Nikola
authors.initials: N
authors.lastname: Marjanović
authors.forename: Ivanka
authors.initials: I
authors.lastname: Pašalić
authors.forename: Boška
authors.initials: B
authors.lastname: Hrvačić
authors.forename: Denis
authors.initials: D
authors.lastname: Polančec
authors.forename: Ines
authors.initials: I
authors.lastname: Glojnarić
authors.forename: Vesna
authors.initials: V
authors.lastname: Eraković Haber
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D048049:Extracellular Signal-Regulated MAP Kinases / Q000276:immunology / Q000378:metabolism; D007150:Immunohistochemistry; D053583:Interleukin-1beta / Q000096:biosynthesis* / Q000276:immunology; D008070:Lipopolysaccharides / Q000633:toxicity; D008168:Lung / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000276:immunology / Q000378:metabolism; D020556:Neutrophil Infiltration / Q000187:drug effects* / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000037:antagonists & inhibitors*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D016328:NF-kappa B; D018808:Transcription Factor AP-1; C440499:lipopolysaccharide, Escherichia coli O111 B4; D017963:Azithromycin; D048049:Extracellular Signal-Regulated MAP Kinases