title: Azithromycin selectively reduces tumor necrosis factor alpha levels in cystic fibrosis airway epithelial cells.
abstract: Azithromycin (AZM) ameliorates lung function in cystic fibrosis (CF) patients. This macrolide has been suggested to have anti-inflammatory properties as well as other effects potentially relevant for therapy of CF. In this study, we utilized three CF (IB3-1, 16HBE14o- AS3, and 2CFSMEo-) and two isogenic non-CF (C38 and 16HBE14o- S1) airway epithelial cell lines to investigate whether AZM could reduce tumor necrosis factor alpha (TNF-alpha) mRNA and protein levels by real-time quantitative PCR analysis and an enzyme-linked immunosorbent assay (ELISA), respectively. We studied the effects on the DNA binding of NF-kappaB and specificity protein 1 (Sp1) by an ELISA. Non-CF cells express significantly lower TNF-alpha mRNA and protein levels than an isogenic CF cell line. In CF cells, AZM treatment causes a 30% reduction of TNF-alpha mRNA levels (P < 0.05) and a 45% decrease in TNF-alpha secretion (P < 0.05), reaching approximately the levels of the untreated isogenic non-CF cells. In CF cells, NF-kappaB and Sp1 DNA binding activities were also significantly decreased (about 45 and 60%, respectively; P < 0.05) after AZM treatment. Josamycin, a macrolide lacking clinically described anti-inflammatory effects, was ineffective. Finally, AZM did not alter the mRNA expression levels of interleukin-6, a proinflammatory molecule not differentially expressed in CF and isogenic non-CF cells. The results of our study support the anti-inflammatory activities of this macrolide, since we show that AZM reduced the levels of TNF-alpha and propose inhibitions of NF-kappaB and Sp1 DNA binding as possible mechanisms of this effect.
authors.affiliation: Cystic Fibrosis Center-Azienda Ospedaliera di Verona, piazzale Stefani 1, 37126 Verona, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Cigana
authors.forename: Baroukh Maurice
authors.initials: BM
authors.lastname: Assael
authors.forename: Paola
authors.initials: P
authors.lastname: Melotti
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D002460:Cell Line; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis; D015570:Josamycin / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D012313:RNA / Q000096:biosynthesis; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D015850:Interleukin-6; D016328:NF-kappa B; D016329:Sp1 Transcription Factor; D014409:Tumor Necrosis Factor-alpha; D012313:RNA; D017963:Azithromycin; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D015570:Josamycin