HMGB1 binding to receptor for advanced glycation end products enhances inflammatory responses of human bronchial epithelial cells by activating p38 MAPK and ERK1/2

Mol Cell Biochem. 2015 Jul;405(1-2):63-71. doi: 10.1007/s11010-015-2396-0. Epub 2015 Apr 11.

Abstract

The proinflammatory factor high mobility group box protein 1 (HMGB1) has been implicated as an important mediator of many chronic inflammatory diseases, including asthma. Human bronchial epithelial cells (HBECs) play a central role in the pathogenesis of asthma. However, the effects of HMGB1 on HBECs and the underlying mechanisms remain unknown. Here, we investigated receptor expression and proinflammatory cytokine production by primary cultures of HBECs stimulated by HMGB1. We then examined the effects of specific receptor blockade and inhibition of p38 MAPK, ERK1/2, or PI3-K on HMGB1-induced expression of proinflammatory cytokines. HMGB1 increased the expression and secretion of TNF-α, TSLP, MMP-9, and VEGF in a dose- and time-dependent manner. HMGB1 also induced elevated expression of RAGE protein. Secretion of TNF-α, VEGF, MMP-9, and TSLP was significantly decreased by RAGE blockade and p38 MAPK pathway inhibition, while a less pronounced effect was mediated by ERK1/2 inhibition. These observations suggest that HMGB1 binds RAGE and promotes activities of p38 MAPK and ERK1/2 pathways in HBECs. This then enhances the expression of TNF-α, VEGF, MMP-9, and TSLP, which are the important inflammatory factors in asthma. These results demonstrate that HMGB1 enhances the inflammatory responses of HBECs, which are involved in the modulation of inflammatory processes in asthma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bronchi / metabolism*
  • Bronchi / pathology
  • Cytokines / metabolism
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • HMGB1 Protein / metabolism*
  • Humans
  • Inflammation / metabolism*
  • Inflammation / pathology
  • MAP Kinase Signaling System / physiology*
  • Matrix Metalloproteinase 9 / metabolism
  • Protein Binding / physiology
  • Receptor for Advanced Glycation End Products / metabolism*
  • Signal Transduction / physiology
  • Thymic Stromal Lymphopoietin
  • Tumor Necrosis Factor-alpha / metabolism
  • Vascular Endothelial Growth Factor A / metabolism
  • p38 Mitogen-Activated Protein Kinases / metabolism*

Substances

  • Cytokines
  • HMGB1 Protein
  • HMGB1 protein, human
  • Receptor for Advanced Glycation End Products
  • Tumor Necrosis Factor-alpha
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • p38 Mitogen-Activated Protein Kinases
  • Matrix Metalloproteinase 9
  • Thymic Stromal Lymphopoietin