TY - JOUR
T1 - The CYP4A isoforms hydroxylate epoxyeicosatrienoic acids to form high affinity peroxisome proliferator-activated receptor ligands
AU - Ashley Cowart, L.
AU - Wei, Shouzuo
AU - Hsu, Mei Hui
AU - Johnson, Eric F.
AU - Krishna, Murali U.
AU - Falck, J R
AU - Capdevila, Jorge H.
PY - 2002/9/20
Y1 - 2002/9/20
N2 - Cytochromes P450 of the CYP2C and CYP4A gene subfamilies metabolize arachidonic acid to 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs) and to 19-and 20-hydroxyeicosatetraenoic acids (HETEs), respectively. Abundant functional studies indicate that EETs and HETEs display powerful and often opposing biological activities as mediators of ion channel activity and regulators of vascular tone and systemic blood pressures. Incubation of 8,9-, 11,12-, and 14,15-EETs with microsomal and purified forms of rat CYP4A isoforms led to rapid NADPH-dependent metabolism to the corresponding 19- and 20-hydroxylated EETs. Comparisons of reaction rates and catalytic efficiency with those of arachidonic and lauric acids showed that EETs are one of the best endogenous substrates so far described for rat CYP4A isoforms. CYP4A1 exhibited a preference for 8,9-EET, whereas CYP4A2, CYP4A3, and CYP4A8 preferred 11,12-EET. In general, the closer the oxido ring is to the carboxylic acid functionality, the higher the rate of EET metabolism and the lower the regiospecificity for the EET ω-carbon. Analysis of cis-parinaric acid displacement from the ligand-binding domain of the human peroxisome proliferator-activated receptor-α showed that ω-hydroxylated 14,15-EET bound to this receptor with high affinity (Ki = 3 ± 1 nM). Moreover, at 1 μM, the ω-alcohol of 14,15-EET or a 1:4 mixture of the ω-alcohols of 8,9- and 11,12-EETs activated human and mouse peroxisome proliferator-activated receptor-α in transient transfection assays, suggesting a role for them as endogenous ligands for these orphan nuclear receptors.
AB - Cytochromes P450 of the CYP2C and CYP4A gene subfamilies metabolize arachidonic acid to 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs) and to 19-and 20-hydroxyeicosatetraenoic acids (HETEs), respectively. Abundant functional studies indicate that EETs and HETEs display powerful and often opposing biological activities as mediators of ion channel activity and regulators of vascular tone and systemic blood pressures. Incubation of 8,9-, 11,12-, and 14,15-EETs with microsomal and purified forms of rat CYP4A isoforms led to rapid NADPH-dependent metabolism to the corresponding 19- and 20-hydroxylated EETs. Comparisons of reaction rates and catalytic efficiency with those of arachidonic and lauric acids showed that EETs are one of the best endogenous substrates so far described for rat CYP4A isoforms. CYP4A1 exhibited a preference for 8,9-EET, whereas CYP4A2, CYP4A3, and CYP4A8 preferred 11,12-EET. In general, the closer the oxido ring is to the carboxylic acid functionality, the higher the rate of EET metabolism and the lower the regiospecificity for the EET ω-carbon. Analysis of cis-parinaric acid displacement from the ligand-binding domain of the human peroxisome proliferator-activated receptor-α showed that ω-hydroxylated 14,15-EET bound to this receptor with high affinity (Ki = 3 ± 1 nM). Moreover, at 1 μM, the ω-alcohol of 14,15-EET or a 1:4 mixture of the ω-alcohols of 8,9- and 11,12-EETs activated human and mouse peroxisome proliferator-activated receptor-α in transient transfection assays, suggesting a role for them as endogenous ligands for these orphan nuclear receptors.
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U2 - 10.1074/jbc.M201575200
DO - 10.1074/jbc.M201575200
M3 - Article
C2 - 12124379
AN - SCOPUS:0037144475
SN - 0021-9258
VL - 277
SP - 35105
EP - 35112
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 38
ER -