Protective effects of epoxyeicosatrienoic acids on human endothelial cells from the pulmonary and coronary vasculature.
Epoxyeicosatrienoic acids (EETs) are cytochrome P-450 (CYP) metabolites synthesized from the essential fatty acid arachidonic acid to generate four regioisomers, 14,15-, 11,12-, 8,9-, and 5,6-EET. Cultured human coronary artery endothelial cells (HCAECs) contain endogenous EETs that are increased by stimulation with physiological agonists such as bradykinin. Because EETs are known to modulate a number of vascular functions, including angiogenesis, we tested each of the four regioisomers to characterize their effects on survival and apoptosis of HCAECs and cultured human lung microvascular endothelial cells (HLMVECs). A single application of physiologically relevant concentration of 14,15-, 11,12-, and 8,9-EET but not 5,6-EET (0.75-300 nM) promoted concentration-dependent increase in cell survival of HLMVECs and HCAECs after removal of serum. The lipids also protected the same cells from death via the intrinsic, as well as extrinsic, pathways of apoptosis. EETs did not increase intracellular calcium concentration ([Ca2+]i) or phosphorylate mitogen-activated protein kinase p44/42 when applied to these cells, and their protective action was attenuated by the phosphotidylinositol-3 kinase inhibitor wortmannin (10 microM) but not the cyclooxygenase inhibitor indomethacin (20 microM). Our results demonstrate for the first time the capacity of EETs to enhance human endothelial cell survival by inhibiting both the intrinsic, as well as extrinsic, pathways of apoptosis, an important underlying mechanism that may promote angiogenesis and endothelial survival during atherosclerosis and related cardiovascular ailments.
Dhanasekaran
Anuradha
A
Division of Pulmonary and Critical Care, Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
Al-Saghir
Rula
R
Lopez
Bernardo
B
Zhu
Daling
D
Gutterman
David D
DD
Jacobs
Elizabeth R
ER
Medhora
Meetha
M
D015126:8,11,14-Eicosatrienoic Acid / Q000494:pharmacology*; D017304:Annexin A5 / Q000378:metabolism; D019138:Antibodies, Blocking / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001562:Benzimidazoles; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002316:Cardiotonic Agents; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002452:Cell Count; D002470:Cell Survival; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects*; D016895:Culture Media, Serum-Free; D042783:Endothelial Cells / Q000187:drug effects*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D005456:Fluorescent Dyes; D006801:Humans; D007536:Isomerism; D011419:Propidium; D011652:Pulmonary Circulation / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects; D013778:Tetrazolium Salts; D013844:Thiazoles; D019014:fas Receptor / Q000502:physiology
D017304:Annexin A5; D019138:Antibodies, Blocking; D001562:Benzimidazoles; D002316:Cardiotonic Agents; D016895:Culture Media, Serum-Free; D005456:Fluorescent Dyes; D013778:Tetrazolium Salts; D013844:Thiazoles; D019014:fas Receptor; D011419:Propidium; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C022616:thiazolyl blue; D015126:8,11,14-Eicosatrienoic Acid; C017807:bisbenzimide ethoxide trihydrochloride; D002118:Calcium