Details

Autor(en) / Beteiligte

• Yu, Hongmei
• Li, Qi
• Kolosov, Victor P.
• Perelman, Juliy M.
• Zhou, Xiangdong

Titel

Regulation of cigarette smoke-mediated mucin expression by hypoxia-inducible factor-1α via epidermal growth factor receptor-mediated signaling pathways

Ist Teil von

• Journal of applied toxicology, 2012-04, Vol.32 (4), p.282-292

Ort / Verlag

Chichester, UK: John Wiley & Sons, Ltd

Erscheinungsjahr

2012

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• ABSTRACT Cigarette smoking is strongly implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Mucus hypersecretion is the key manifestation in patients with COPD and mucin 5AC (MUC5AC) is a major component of airway mucus. Hypoxia inducible factor‐1 (HIF‐1) is a transcriptional factor which can be stimulated to bind to the MUC5AC promoter and induce MUC5AC promoter activation. Previous studies have reported that activation of HIF‐1α pathways by cigarette smoke contributes to the development of COPD. We hypothesize that cigarette smoke up‐regulates HIF‐1α production and HIF‐1 activity through epidermal growth factor receptor (EGFR)‐activated signal cascades pathways, leading to mucin production in human airway epithelial cells (16HBE). We show that cigarette smoke increases HIF‐1α production, HIF‐1 activity and MUC5AC expression. These effects are prevented by small interfering RNA (siRNA) for HIF‐1α, indicating that cigarette smoke‐induced mucin production is HIF‐1α‐dependent. Cigarette smoke activates extracellular signal‐regulated kinase 1/2 (ERK1/2) and phosphatidylinositol 3‐kinase (PI3K) signal pathways, both of which are inhibited by gefitinib (an inhibitor of EGFR), suggesting that cigarette smoke‐activated signal pathways are mediated by EGFR in 16HBE cells. Furthermore, pretreatment with gefitinib and the pharmacological inhibitors of PI3K (LY294002) and ERK1/2 (PD98059) prevented cigarette smoke‐mediated Akt and ERK1/2 phosphorylation responses, HIF‐1α production, HIF‐1 activity and MUC5AC expression. These observations demonstrate an important role for EGFR‐mediated signaling pathways in regulating cigarette smoke‐induced HIF‐1 activation and MUC5AC expression. Our results suggest that cigarette smoke activates EGFR‐mediated signaling pathways, leading to HIF‐1α production and HIF‐1 activation, resulting in mucin expression in human airway epithelial cells. Copyright © 2011 John Wiley & Sons, Ltd. Cigarette smoke increases HIF‐1α production, HIF‐1 activity and MUC5AC expression in 16HBE cells, effects that are prevented HIF‐1α siRNA. Cigarette smoke activates ERK1/2 and PI3K signal pathways by EGFR. The pharmacological inhibitors of EGFR, PI3K (LY294002) and ERK1/2 (PD98059) prevented cigarette smoke‐mediated Akt and ERK1/2 phosphorylation responses, HIF‐1α production, HIF‐1 activity and MUC5AC expression. These results suggest that cigarette smoke activates EGFR‐mediated signaling pathways, leading to HIF‐1α production and HIF‐1 activation, resulting in mucin expression in 16HBE cells.