Oxygenation of omega-3 fatty acids by human cytochrome P450 4F3B: effect on 20-hydroxyeicosatetraenoic acid production.
Cytochrome P450 (CYP) omega-oxidases convert arachidonic acid (AA) to 20-hydroxyeicosatetraenoic acid (20-HETE), a lipid mediator that modulates vascular tone. We observed that a microsomal preparation containing recombinant human CYP4F3B, which converts AA to 20-HETE, converted eicosapentaenoic acid (EPA) to 20-OH-EPA. Likewise, docosahexaenoic acid (DHA) was converted to 22-OH-DHA, indicating that human CYP4F3B also can oxidize 22-carbon omega-3 fatty acids. Consistent with these findings, addition of 0.5-5 microM EPA, DHA or omega-3 docosapentaenoic acid (DPA) to incubations containing 0.5 microM [3H]AA inhibited [3H]20-HETE production by 15-65%. [3H]20-OH-EPA was rapidly taken up by COS-7 cells, and almost all of the incorporated radioactivity remained as unmodified 20-OH-EPA. The 20-OH-EPA stimulated luciferase activity in COS-7 cells that express peroxisome proliferator-activated receptor alpha, indicating that this EPA metabolite may function as a lipid mediator. These findings suggest that some functional effects of omega-3 fatty acid supplementation may be due to inhibition of 20-HETE formation or the conversion of EPA to the corresponding omega-oxidized product.
Harmon
Shawn D
SD
Department of Biochemistry, Carver College of Medicine, 4-403 BSB, University of Iowa, Iowa City, IA 52242, USA.
Fang
Xiang
X
Kaduce
Terry L
TL
Hu
Shanming
S
Raj Gopal
V
V
Falck
John R
JR
Spector
Arthur A
AA
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D019556:COS Cells; D002522:Chlorocebus aethiops; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D000072470:Cytochrome P450 Family 4; D004281:Docosahexaenoic Acids / Q000378:metabolism / Q000494:pharmacology; D015118:Eicosapentaenoic Acid / Q000378:metabolism / Q000494:pharmacology; D015525:Fatty Acids, Omega-3 / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism*; D050356:Lipid Metabolism / Q000187:drug effects; D013058:Mass Spectrometry / Q000379:methods; D010084:Oxidation-Reduction / Q000187:drug effects; D010100:Oxygen / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
D065607:Cytochrome P-450 Enzyme Inhibitors; D015525:Fatty Acids, Omega-3; D006893:Hydroxyeicosatetraenoic Acids; D011994:Recombinant Proteins; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid; D003577:Cytochrome P-450 Enzyme System; D015118:Eicosapentaenoic Acid; D000072470:Cytochrome P450 Family 4; C465349:CYP4F3 protein, human; D010100:Oxygen