Multiple antiapoptotic targets of the PI3K/Akt survival pathway are activated by epoxyeicosatrienoic acids to protect cardiomyocytes from hypoxia/anoxia

Am J Physiol Heart Circ Physiol. 2008 Feb;294(2):H724-35. doi: 10.1152/ajpheart.00979.2007. Epub 2007 Nov 30.


Epoxyeicosatrienoic acids (EETs) reduce infarction of the myocardium after ischemia-reperfusion injury to rodent and dog hearts mainly by opening sarcolemmal and mitochondrial potassium channels. Other mediators for the action of EET have been proposed, although no definitive pathway or mechanism has yet been reported. Using cultured cells from two rodent species, immortalized myocytes from a mouse atrial lineage (HL-1) and primary myocytes derived from neonatal rat hearts, we observed that pretreatment with EETs (1 microM of 14,15-, 11,12-, or 8,9-EET) attenuated apoptosis after exposure to hypoxia and reoxygenation (H/R). EETs also preserved the functional beating of neonatal myocytes in culture after exposure to H/R. We demonstrated that EETs increased the activity of the prosurvival enzyme phosphatidylinositol 3-kinase (PI3K). In fact, cardiomyocytes pretreated with EET and exposed to H/R exhibited antiapoptotic changes in at least five downstream effectors of PI3K, protein kinase B (Akt), Bcl-x(L)/Bcl-2-associated death promoter, caspases-9 and -3 activities, and the expression of the X-linked inhibitor of apoptosis, compared with vehicle-treated controls. The PI3K/Akt pathway is one of the strongest intracellular prosurvival signaling systems. Our studies show that EETs regulate multiple molecular effectors of this pathway. Understanding the targets of action of EET-mediated protection will promote the development of these fatty acids as therapeutic agents against cardiac ischemia-reperfusion.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Animals, Newborn
  • Annexin A5 / metabolism
  • Apoptosis / physiology*
  • Benzimidazoles
  • Blotting, Western
  • Caspase 3 / biosynthesis
  • Caspase 9 / biosynthesis
  • Cell Hypoxia / physiology*
  • Cell Line
  • Cell Survival / physiology
  • Cells, Cultured
  • Eicosanoids / pharmacology*
  • Fluorescent Antibody Technique
  • Fluorescent Dyes
  • Myocytes, Cardiac / physiology*
  • Phosphatidylinositol 3-Kinases / physiology*
  • Phosphorylation
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / physiology*
  • Tetrazolium Salts
  • Thiazoles
  • X-Linked Inhibitor of Apoptosis Protein / biosynthesis
  • X-Linked Inhibitor of Apoptosis Protein / physiology
  • bcl-X Protein / metabolism


  • Annexin A5
  • Benzimidazoles
  • Eicosanoids
  • Fluorescent Dyes
  • Tetrazolium Salts
  • Thiazoles
  • X-Linked Inhibitor of Apoptosis Protein
  • bcl-X Protein
  • Phosphatidylinositol 3-Kinases
  • Caspase 3
  • Caspase 9
  • thiazolyl blue
  • bisbenzimide ethoxide trihydrochloride