Signal transduction for proteinase-activated receptor-2-triggered prostaglandin E2 formation in human lung epithelial cells

J Pharmacol Exp Ther. 2005 Nov;315(2):576-89. doi: 10.1124/jpet.105.089490. Epub 2005 Aug 24.

Abstract

We investigated proteinase-activated receptor-2 (PAR(2))-triggered signal transduction pathways causing increased prostaglandin E(2) (PGE(2)) formation in human lung-derived A549 epithelial cells. The PAR(2) agonist, SLIGRL-NH(2) (Ser-Leu-Ile-Gly-Arg-Leu-amide), evoked immediate cytosolic Ca(2+) mobilization and delayed (0.5-3 h) PGE(2) formation. The PAR(2)-triggered PGE(2) formation was attenuated by inhibition of the following signal pathway enzymes: cyclooxygenases 1 and 2 (COX-1 and COX-2, respectively), cytosolic Ca(2+)-dependent phospholipase A(2) (cPLA(2)), the mitogen-activated protein kinases (MAPKs), mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) and p38 MAPK, Src family tyrosine kinase, epidermal growth factor (EGF) receptor tyrosine kinase (EGFRK), and protein kinase C (PKC), but not by inhibition of matrix metalloproteinases. SLIGRL-NH(2) caused prompt (5 min) and transient ERK phosphorylation, blocked in part by inhibitors of PKC and tyrosine kinases but not by an EGFRK inhibitor. SLIGRL-NH(2) also evoked a relatively delayed (15 min) and persistent (30 min) phosphorylation of p38 MAPK, blocked by inhibitors of Src and EGFRK but not by inhibitors of COX-1 or COX-2. SLIGRL-NH(2) elicited a Src inhibitor-blocked prompt (5 min) and transient phosphorylation of the EGFRK. SLIGRL-NH(2) up-regulated COX-2 protein and/or mRNA levels that were blocked by inhibition of p38 MAPK, EGFRK, Src, and COX-2 but not MEK-ERK. SLIGRL-NH(2) also caused COX-1-dependent up-regulation of microsomal PGE synthase-1 (mPGES-1). We conclude that PAR(2)-triggered PGE(2) formation in A549 cells involves a coordinated up-regulation of COX-2 and mPGES-1 involving cPLA(2), increased cytosolic Ca(2+), PKC, Src, MEK-ERK, p38 MAPK, Src-mediated EGF receptor trans-activation, and also metabolic products of both COX-1 and COX-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Calcium / metabolism
  • Cell Line
  • Cell Proliferation / drug effects
  • Cyclooxygenase 1 / biosynthesis
  • Cyclooxygenase 2 / biosynthesis
  • Cytosol / drug effects
  • Cytosol / metabolism
  • Dinoprostone / biosynthesis*
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism*
  • ErbB Receptors / metabolism
  • Humans
  • Immunohistochemistry
  • Lung / cytology
  • Lung / drug effects
  • Lung / metabolism*
  • Microsomes / drug effects
  • Microsomes / enzymology
  • Phosphorylation
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Receptor, PAR-1 / agonists
  • Receptor, PAR-2 / agonists
  • Receptor, PAR-2 / physiology*
  • Receptors, Estrogen / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / drug effects*
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • RNA, Messenger
  • Receptor, PAR-1
  • Receptor, PAR-2
  • Receptors, Estrogen
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • ErbB Receptors
  • p38 Mitogen-Activated Protein Kinases
  • Dinoprostone
  • Calcium