Lipoxin A4 inhibits 5-lipoxygenase translocation and leukotrienes biosynthesis to exert a neuroprotective effect in cerebral ischemia/reperfusion injury

J Mol Neurosci. 2012 Sep;48(1):185-200. doi: 10.1007/s12031-012-9807-4. Epub 2012 Jun 3.

Abstract

Lipoxin A(4) (LXA(4)), a biologically active eicosanoid with anti-inflammatory and pro-resolution properties, was recently found to have neuroprotective effects in brain ischemia. As 5-lipoxygenase (5-LOX) and leukotrienes are generally considered to aggravate cerebral ischemia/reperfusion (I/R) injury, we investigated their effects on LXA(4)-mediated neuroprotection by studying middle cerebral artery occlusion (MCAO)/reperfusion in rats and oxygen-glucose deprivation (OGD)/recovery in neonatal rat astrocyte primary cultures. LXA(4) effectively reduced infarct volumes and brain edema, and improved neurological scores in the MCAO/reperfusion experiments; this effect was partially blocked by butoxycarbonyl-Phe-Leu-Phe-Leu-Phe (Boc2), a specific antagonist of the LXA(4) receptor (ALXR). Total 5-LOX expression did not change, regardless of treatment, but LXA(4) could inhibit nuclear translocation induced by MCAO or OGD. We also found that LXA(4) inhibits the upregulation of both leukotriene B(4) (LTB(4)) and leukotriene C(4) (LTC(4)) and the phosphorylation of extracellular signal-regulated kinase (ERK) induced by MCAO or OGD. The phosphorylation of the 38-kDa protein kinase (p38) and c-Jun N-terminal kinase (JNK) was not altered throughout the experiment. These results suggest that the neuroprotective effects of LXA(4) are probably achieved by anti-inflammatory mechanisms that are partly mediated by ALXR and through an ERK signal transduction pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Arachidonate 5-Lipoxygenase / metabolism*
  • Astrocytes / cytology
  • Astrocytes / drug effects
  • Astrocytes / metabolism
  • Brain Edema / drug therapy
  • Brain Edema / metabolism
  • Brain Edema / pathology
  • Brain Ischemia / drug therapy*
  • Brain Ischemia / metabolism
  • Brain Ischemia / pathology
  • Disease Models, Animal
  • Enzyme Inhibitors / pharmacology
  • Flavonoids / pharmacology
  • Glucose / pharmacology
  • Leukotriene B4 / metabolism
  • Leukotriene C4 / genetics
  • Leukotriene C4 / metabolism
  • Leukotrienes / biosynthesis*
  • Leukotrienes / metabolism
  • Lipoxins / pharmacology*
  • MAP Kinase Signaling System / drug effects
  • Male
  • Neuroprotective Agents / pharmacology*
  • Oxygen / pharmacology
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Reperfusion Injury / drug therapy*
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / pathology

Substances

  • Enzyme Inhibitors
  • Flavonoids
  • Leukotrienes
  • Lipoxins
  • Neuroprotective Agents
  • RNA, Messenger
  • lipoxin A4
  • Leukotriene B4
  • Leukotriene C4
  • Arachidonate 5-Lipoxygenase
  • Glucose
  • Oxygen
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one