PT - JOURNAL ARTICLE AU - Martina Bosnar AU - Berislav Bošnjak AU - Snježana Čužić AU - Boška Hrvačić AU - Nikola Marjanović AU - Ines Glojnarić AU - Ognjen Čulić AU - Michael J. Parnham AU - Vesna Eraković Haber TI - Azithromycin and Clarithromycin Inhibit Lipopolysaccharide-Induced Murine Pulmonary Neutrophilia Mainly through Effects on Macrophage-Derived Granulocyte-Macrophage Colony-Stimulating Factor and Interleukin-1β AID - 10.1124/jpet.109.155838 DP - 2009 Oct 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 104--113 VI - 331 IP - 1 4099 - http://jpet.aspetjournals.org/content/331/1/104.short 4100 - http://jpet.aspetjournals.org/content/331/1/104.full SO - J Pharmacol Exp Ther2009 Oct 01; 331 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