RT Journal Article SR Electronic T1 Azithromycin and Clarithromycin Inhibit Lipopolysaccharide-Induced Murine Pulmonary Neutrophilia Mainly through Effects on Macrophage-Derived Granulocyte-Macrophage Colony-Stimulating Factor and Interleukin-1β JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 104 OP 113 DO 10.1124/jpet.109.155838 VO 331 IS 1 A1 Martina Bosnar A1 Berislav Bošnjak A1 Snježana Čužić A1 Boška Hrvačić A1 Nikola Marjanović A1 Ines Glojnarić A1 Ognjen Čulić A1 Michael J. Parnham A1 Vesna Eraković Haber YR 2009 UL http://jpet.aspetjournals.org/content/331/1/104.abstract AB Macrolide antibiotics possess immunomodulatory/anti-inflammatory properties. These properties are considered fundamental for the efficacy of macrolide antibiotics in the treatment of chronic inflammatory diseases like diffuse panbronchiolitis and cystic fibrosis. However, the molecular mechanisms and cellular targets of anti-inflammatory/immunomodulatory macrolide activity are still not fully understood. To describe anti-inflammatory effects of macrolides in more detail and to identify potential biomarkers of their activity, we have investigated the influence of azithromycin and clarithromycin on the inflammatory cascade leading to neutrophil infiltration into lungs after intranasal lipopolysaccharide challenge in mice. Azithromycin and clarithromycin pretreatment reduced total cell and neutrophil numbers in bronchoalveolar lavage fluid and myeloperoxidase concentration in lung tissue. In addition, concentrations of several inflammatory mediators, including CCL2, granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-1β (IL-1β), tumor necrosis factor α, and sE-selectin in lung homogenates were decreased after macrolide treatment. Inhibition of cytokine production observed in vivo was also corroborated in vitro in lipopolysaccharide-stimulated monocytes/macrophages, but not in an epithelial cell line. In summary, results presented in this article confirm that macrolides can suppress neutrophil-dominated pulmonary inflammation and suggest that the effect is mediated through inhibition of GM-CSF and IL-1β production by alveolar macrophages. Besides GM-CSF and IL-1β, CCL2 and sE-selectin are also identified as potential biomarkers of macrolide anti-inflammatory activity in the lungs. © 2009 by the American Society for Pharmacology and Experimental Therapeutics