EP2 receptor activation by prostaglandin E2 leads to induction of HO-1 via PKA and PI3K pathways in C6 cells

Biochem Biophys Res Commun. 2009 Feb 20;379(4):1043-7. doi: 10.1016/j.bbrc.2009.01.005. Epub 2009 Jan 10.

Abstract

Recently we proposed that COX-2 induction precedes expression of HO-1 in ischemic preconditioned rat brain. In the current study, we investigated the molecular mechanism by which prostaglandin E(2), one of COX-2 metabolites, induces HO-1 in rat C6 brain cells. We demonstrated that concentration of PGE(2) increased HO-1 expression in C6 cells in vitro. The effects of PGE(2) were mimicked by PGE(2) receptor EP(2) agonists, 11-deoxy PGE(2), and cAMP analog, dibutyl-cAMP. HO-1 expression by PGE(2) was inhibited by LY294002, PI3K inhibitor and H89, PKA inhibitor. The EP(2)-specific antagonist, AH8006 also inhibited PGE(2)-mediated HO-1 expression in a concentration-dependent manner. Finally, PGE(2) inhibited GOX-induced apoptosis as assayed by FACS analysis or DNA strand breaks assay, and this cell death was reversed by ZnPPIX, HO-1 inhibitor. In addition to HO-1 induction, PGE(2) also increased phosphorylation of Bad by PKA- and PI3K-depednent manner. Taken together, we conclude that PGE(2) induces HO-1 protein expression through PKA and PI3K signaling pathways via EP(2) receptor in C6 cells. The induction of HO-1 along with increase of p-Bad by PGE(2) is responsible for anti-apoptosis against oxidant stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Cell Line, Tumor
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Dinoprostone / metabolism*
  • Dinoprostone / pharmacology
  • Heme Oxygenase-1 / antagonists & inhibitors
  • Heme Oxygenase-1 / biosynthesis*
  • Oxidative Stress
  • Phosphatidylinositol 3-Kinases / metabolism
  • Protoporphyrins / pharmacology
  • Rats
  • Receptors, Prostaglandin E / agonists*
  • Receptors, Prostaglandin E, EP2 Subtype
  • bcl-Associated Death Protein / metabolism

Substances

  • Protoporphyrins
  • Ptger2 protein, rat
  • Receptors, Prostaglandin E
  • Receptors, Prostaglandin E, EP2 Subtype
  • bcl-Associated Death Protein
  • zinc protoporphyrin
  • Heme Oxygenase-1
  • Phosphatidylinositol 3-Kinases
  • Cyclic AMP-Dependent Protein Kinases
  • Dinoprostone