IL-8 In Bronchial Epithelial Cells Research Articles

Investigating the effect of pretreatment with azithromycin on inflammatory mediators in bronchial epithelial cells exposed to cigarette smoke

Purpose of the study: Macrolide therapy is effective in reducing chronic obstructive pulmonary disease (COPD) exacerbations. Our recent study has shown the effectiveness of taking azithromycin in COPD patients, not only ex-smokers but also current smokers. Beyond their anti-microbial effects, macrolides have anti-inflammatory and immunomodulatory properties. The aim of this study was to determine if pretreatment with azithromycin modulates cigarette smoke-induced inflammation in airway epithelial cells. We hypothesized that pretreatment with azithromycin decreases exacerbation frequency by modulating inflammation in human airway epithelial cells exposed to cigarette smoke. Materials and methods: BEAS-2B bronchial epithelial cells were incubated with 5% cigarette smoke extract (CSE) for 3 h, 6 h, and 24 h. Then, airway epithelial cells were pretreated with azithromycin and exposed to 5% CSE. In each stage, the expression and release of IL-6 and IL-8 mRNA were analyzed by quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Results: There was a significant increase of IL-6 and IL-8 mRNA, as well as an increase in extracellular IL-8 protein following exposure to 5% CSE. When cells were pretreated with azithromycin and exposed to 5% CSE for 3 h, there was a significant dose-dependent decrease in the expression of IL-6 mRNA. A final concentration of 9 µg/mL of azithromycin was sufficient to decrease IL-6, IL-8 mRNA, and extracellular IL-8 levels. Conclusion: Pretreatment with azithromycin decreased the expression of IL-6 and IL-8 mRNA and the release of IL-8 in bronchial epithelial cells exposed to cigarette smoke. These results demonstrate the direct effect of azithromycin on inflammatory mediators in bronchial epithelial cells exposed to cigarette smoke.

Interleukin-1α induced release of interleukin-8 by human bronchial epithelial cells in vitro: assessing mechanisms and possible treatment options.

Survival after lung transplantation is hampered by chronic lung allograft dysfunction (CLAD). Persistently elevated BAL-neutrophilia is observed in some patients despite treatment with azithromycin, which may be induced by IL-1α. Our aim is to establish an in vitro model, assess mechanistic pathways and test different therapeutic strategies of IL-1α-induced release of IL-8 by human bronchial epithelial cells. Bronchial epithelial cells (16HBE) were stimulated with IL-1α with or without azithromycin or dexamethasone. IL-8 protein was analyzed in cell supernatant. Different MAP kinases (p38, JNK, ERK1/2 , Iκβ) and targets known to be involved in tumor formation (PI3K, Akt) were investigated. Finally, different treatment options were tested for their potential inhibitory effect. IL-1α induced IL-8 in bronchial epithelial cells, which was dose-dependently inhibited by dexamethasone but not by azithromycin. IL-1α induced p38 and Akt phosphorylation, but activation of these MAPK was not inhibited by dexamethasone. JNK, ERK1/2 , Iκβ and PI3K were not activated. None of the tested drugs reduced the IL-1α induced IL-8 production. We established an in vitro model wherein steroids inhibit the IL-1α-induced IL-8 production, while azithromycin was ineffective. Despite using this simple in vitro model, we could not identify a new treatment option for azithromycin-resistant airway neutrophilia.

IL-17B is elevated in patients with pneumonia and mediates IL-8 production in bronchial epithelial cells

The role of IL-17B in regulating pulmonary immunity and inflammation is unknown. In this study, we found that IL-17B concentrations were significantly elevated in adult and paediatric patients with community-acquired pneumonia relative to their corresponding healthy adult and paediatric controls. The increased concentrations of IL-17B significantly and positively correlated with chemokine IL-8 concentrations in clinical pneumonia. In vitro studies demonstrated that IL-17B could induce gene and protein expression of IL-8 in human bronchial epithelial cells, but not lung fibroblasts, which was regulated by the activation of Akt, p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) and nuclear factor-kappaB (NF-κB) signaling pathways. In vivo studies further showed that increased IL-17B levels significantly and positively correlated with IL-8 concentrations in experimental pneumonia. In conclusion, human pneumonia was associated with enhanced release of IL-17B, which might regulate pulmonary immunity and inflammation through the induction of IL-8 in bronchial epithelial cells.