PAR-2 activation increases human intestinal mucin secretion through EGFR transactivation

Biochem Biophys Res Commun. 2007 Dec 21;364(3):689-94. doi: 10.1016/j.bbrc.2007.10.073. Epub 2007 Oct 22.

Abstract

PAR-2 (protease-activated receptors-2) are G protein-coupled receptors whose action on mucin secretion by intestinal epithelial cells is still unknown. The aim of this study was to examine the effect of PAR-2 activation on mucin secretion in the human colonic goblet cell line HT29-Cl.16E and the intracellular pathways involved. We found that PAR-2 mRNA was constitutively expressed by HT29-Cl.16E cells as well as by isolated human normal colonocytes. The PAR-2-activating peptide SLIGKV-NH(2) elicited rapid mucin secretion in HT29-Cl.16E, which was partially inhibited by calcium chelator BAPTA. Inhibitors of MAPK activation (PD98059) and EGFR tyrosine kinase activity (AG1478) abrogated PAR-2-induced ERK1/2 and EGFR tyrosine phosphorylation, respectively, and subsequent mucin secretion. Finally, PAR-2-induced EGFR transactivation was involved upstream of ERK1/2 activation. Our results show that the activation of PAR-2 expressed by human intestinal epithelial cells enhances mucin secretion, a component of the intestinal innate defence, via a pathway involving EGFR transactivation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Signaling
  • Enzyme Activation
  • ErbB Receptors / genetics*
  • Gene Expression Regulation
  • HT29 Cells
  • Humans
  • Intestinal Secretions / metabolism*
  • Mitogen-Activated Protein Kinases / metabolism
  • Mucins / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptor, PAR-2 / genetics
  • Receptor, PAR-2 / metabolism*
  • Transcriptional Activation / genetics*

Substances

  • Mucins
  • RNA, Messenger
  • Receptor, PAR-2
  • ErbB Receptors
  • Mitogen-Activated Protein Kinases