Epigallocatechin-3-gallate inhibits interleukin-1β-induced MUC5AC gene expression and MUC5AC secretion in normal human nasal epithelial cells

• Published in: The Journal of nutritional biochemistry 2008-08, Vol.19 (8), p.536-544
• Main Authors: Kim, Hyun Jik, Park, Sang Ho, Park, Sung-Yoon, Moon, Uk Yeol, Lee, Byung Don, Yoon, Sung Hyun, Lee, Jeung-Gweon, Baek, Seung Joon, Yoon, Joo-Heon
• Format: Article
• Language: English
• Subjects: anti-inflammatory agents; biochemical pathways; Biological and medical sciences; cultured cells; dosage; EGCG; epigallocatechin-3-gallate; Feeding. Feeding behavior; flavanols; Fundamental and applied biological sciences. Psychology; gallic acid; gene expression; gene expression regulation; green tea; humans; IL-1β; inflammation; interleukin-1; messenger RNA; MUC5AC; nasal mucosa; polymerase chain reaction; polyphenols; protein kinases; signal transduction; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0955-2863; 1873-4847
• DOI: 10.1016/j.jnutbio.2007.06.010

It has been reported that the proinflammatory cytokine interleukin-1β (IL-1β) induces mucus hypersecretion in normal human nasal epithelial (NHNE) cells and that the MAP kinase pathway may be an important signal pathway in IL-1β-induced MUC5AC gene expression. Green tea ( Camellia sinensis) polyphenols are potent anti-inflammatory agents and have been shown to inhibit inflammation in tumor cell lines and cultured respiratory epithelial cells. In this study, we examined the effect of (−)-epigallocatechin-3-gallate (EGCG), a green tea polyphenol, on IL-1β-induced MUC5AC gene expression and secretion in NHNE cells. After cells had been treated with IL-1β (10 ng/ml) and pretreated with EGCG (10, 50 and 100 μM), mRNA expression of MUC5AC was determined by real-time polymerase chain reaction. The suppression of each signal pathway protein was determined by Western blot analysis after treatment with IL-1β and EGCG, respectively. IL-1β increased MUC5AC gene expression and MUC5AC secretion. EGCG markedly suppressed IL-1β-induced MUC5AC gene expression and MUC5AC secretion via suppression of the phosphorylation of ERK MAP kinase, MSK1, and transcription factor, cAMP response element-binding protein. IL-1β increased the number of cells staining positive with MUC5AC antibodies, and EGCG treatment decreased this number. Our data suggest that EGCG may be an effective inhibitor of IL-1β-induced mucus hypersecretion.