Lymphotoxin β receptor signaling induces IL-8 production in human bronchial epithelial cells

PLoS One. 2014 Dec 11;9(12):e114791. doi: 10.1371/journal.pone.0114791. eCollection 2014.

Abstract

Asthma-related mortality has been decreasing due to inhaled corticosteroid use, but severe asthma remains a major clinical problem. One characteristic of severe asthma is resistance to steroid therapy, which is related to neutrophilic inflammation. Recently, the tumor necrosis factor superfamily member (TNFSF) 14/LIGHT has been recognized as a key mediator in severe asthmatic airway inflammation. However, the profiles and intracellular mechanisms of cytokine/chemokine production induced in cells by LIGHT are poorly understood. We aimed to elucidate the molecular mechanism of LIGHT-induced cytokine/chemokine production by bronchial epithelial cells. Human bronchial epithelial cells express lymphotoxin β receptor (LTβR), but not herpesvirus entry mediator, which are receptors for LIGHT. LIGHT induced various cytokines/chemokines, such as interleukin (IL)-6, oncostatin M, monocyte chemotactic protein-1, growth-regulated protein α and IL-8. Specific siRNA for LTβR attenuated IL-6 and IL-8 production by BEAS-2B and normal human bronchial epithelial cells. LIGHT activated intracellular signaling, such as mitogen-activated protein kinase and nuclear factor-κB (NF-κB) signaling. LIGHT also induced luciferase activity of NF-κB response element, but not of activator protein-1 or serum response element. Specific inhibitors of phosphorylation of extracellular signal-regulated kinase (Erk) and that of inhibitor κB attenuated IL-8 production, suggesting that LIGHT-LTβR signaling induces IL-8 production via the Erk and NF-κB pathways. LIGHT, via LTβR signaling, may contribute to exacerbation of airway neutrophilic inflammation through cytokine and chemokine production by bronchial epithelial cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asthma / genetics*
  • Asthma / pathology
  • Bronchi / metabolism
  • Bronchi / pathology
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology
  • Humans
  • Inflammation / genetics*
  • Inflammation / pathology
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Interleukin-8 / biosynthesis*
  • Interleukin-8 / genetics
  • Lymphotoxin beta Receptor / genetics*
  • Lymphotoxin beta Receptor / metabolism
  • MAP Kinase Signaling System / genetics
  • Mitogen-Activated Protein Kinases / genetics
  • Mitogen-Activated Protein Kinases / metabolism
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Signal Transduction
  • Tumor Necrosis Factor Ligand Superfamily Member 14 / genetics*
  • Tumor Necrosis Factor Ligand Superfamily Member 14 / metabolism
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • p38 Mitogen-Activated Protein Kinases / genetics

Substances

  • IL6 protein, human
  • Interleukin-6
  • Interleukin-8
  • Lymphotoxin beta Receptor
  • NF-kappa B
  • TNFSF14 protein, human
  • Tumor Necrosis Factor Ligand Superfamily Member 14
  • Tumor Necrosis Factor-alpha
  • Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases

Grants and funding

This study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (Research Project Number:24591125) [http://www.jsps.go.jp/j-grantsinaid/index.html] to YY. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.