Novel lipid mediator aspirin-triggered lipoxin A4 induces heme oxygenase-1 in endothelial cells

Am J Physiol Cell Physiol. 2005 Sep;289(3):C557-63. doi: 10.1152/ajpcell.00045.2005. Epub 2005 May 18.

Abstract

Lipoxins (LX) and aspirin-triggered LX (ATL) are eicosanoids generated during inflammation via transcellular biosynthetic routes that elicit distinct anti-inflammatory and proresolution bioactions, including inhibition of leukocyte-mediated injury, stimulation of macrophage clearance of apoptotic neutrophils, repression of proinflammatory cytokine production, and inhibition of cell proliferation and migration. Recently, it was reported that aspirin induces heme oxygenase-1 (HO-1) expression on endothelial cells (EC) in a COX-independent manner, what confers protection against prooxidant insults. However, the underlying mechanisms remain unclear. In this study, we investigated whether an aspirin-triggered lipoxin A(4) stable analog, 15-epi-16-(para-fluoro)-phenoxy-lipoxin A(4) (ATL-1) was able to induce endothelial HO-1. Western blot analysis showed that ATL-1 increased HO-1 protein expression associated with increased mRNA levels on EC in a time- and concentration-dependent fashion. This phenomenon appears to be mediated by the activation of the G protein-coupled LXA(4) receptor because pertussis toxin and Boc-2, a receptor antagonist, significantly inhibited ATL-1-induced HO-1 expression. We demonstrate that treatment of EC with ATL-1 inhibited VCAM and E-selectin expression induced by TNF-alpha or IL-1beta. This inhibitory effect of the analog is modulated by HO-1 because it was blocked by SnPPIX, a competitive inhibitor that blocks HO-1 activity. Our results establish that ATL-1 induces HO-1 in human EC, revealing an undescribed mechanism for the anti-inflammatory activity of these lipid mediators.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Reaction / drug therapy
  • Acute-Phase Reaction / metabolism
  • Aspirin / pharmacology*
  • Cyclooxygenase Inhibitors / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • E-Selectin / metabolism
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / enzymology*
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Enzymologic / immunology
  • Heme Oxygenase (Decyclizing) / genetics
  • Heme Oxygenase (Decyclizing) / metabolism*
  • Heme Oxygenase-1
  • Humans
  • Lipoxins / metabolism
  • Lipoxins / pharmacology*
  • Membrane Proteins
  • Oligopeptides / pharmacology
  • Pertussis Toxin / pharmacology
  • RNA, Messenger / analysis
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Umbilical Veins / cytology
  • Vascular Cell Adhesion Molecule-1 / metabolism

Substances

  • 16-(4-fluorophenoxy)lipoxin A4
  • Cyclooxygenase Inhibitors
  • E-Selectin
  • Lipoxins
  • Membrane Proteins
  • Oligopeptides
  • RNA, Messenger
  • Vascular Cell Adhesion Molecule-1
  • lipoxin A4
  • butyloxycarbonyl-phenylalanyl-leucyl-phenylalanyl-leucyl-phenylalanine
  • HMOX1 protein, human
  • Heme Oxygenase (Decyclizing)
  • Heme Oxygenase-1
  • Pertussis Toxin
  • Aspirin