[42] Cytochrome P450 arachidonic acid epoxygenase: Stereochemical characterization of epoxyeicosatrienoic acids

Capdevila, Jorge H.; Dishman, Elizabeth; Karara, Armando; Falck, J. R.

doi:10.1016/0076-6879(91)06113-h

Cited by 73 publications

(95 citation statements)

References 11 publications

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“…These same product ions were also used for the deuterated internal standards. Quantifications were performed using the ratio of the area of the DHET peaks compared to the area of the corresponding deuterated DHET peaks (Capdevila et al ., 1991; Nakagawa et al ., 2006). …”

Section: Methodsmentioning

confidence: 99%

IGF‐1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging

et al. 2015

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SummaryAging is associated with marked deficiency in circulating IGF‐1, which has been shown to contribute to age‐related cognitive decline. Impairment of moment‐to‐moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of age‐related cognitive impairment. To establish the link between IGF‐1 deficiency and cerebromicrovascular impairment, neurovascular coupling mechanisms were studied in a novel mouse model of IGF‐1 deficiency (Igf1 f/f‐TBG‐Cre‐AAV8) and accelerated vascular aging. We found that IGF‐1‐deficient mice exhibit neurovascular uncoupling and show a deficit in hippocampal‐dependent spatial memory test, mimicking the aging phenotype. IGF‐1 deficiency significantly impaired cerebromicrovascular endothelial function decreasing NO mediation of neurovascular coupling. IGF‐1 deficiency also impaired glutamate‐mediated CBF responses, likely due to dysregulation of astrocytic expression of metabotropic glutamate receptors and impairing mediation of CBF responses by eicosanoid gliotransmitters. Collectively, we demonstrate that IGF‐1 deficiency promotes cerebromicrovascular dysfunction and neurovascular uncoupling mimicking the aging phenotype, which are likely to contribute to cognitive impairment.

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Section: Methodsmentioning

confidence: 99%

IGF‐1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging

et al. 2015

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“…The cell pellets were suspended in PBS, mixed with 10 ng each of 1-14 C-labeled EETs and DHETs (55 Ci/mol), and extracted with CHCl 3 /CH 3 OH (2:1). The organic extracts were submitted to alkaline hydrolysis, and EETs and DHETs purified and quantified by NICI/ GC/MS exactly as described (26). Prior to use, synthetic EETs and DHETs were purified by reversed-phase HPLC (25).…”

Section: Synthesis Of Eets By Endothelialmentioning

confidence: 99%

“…and Biosynthesize EETs-To establish the presence of a functional epoxygenase in mouse lung endothelial cells, we quantified cellular EETs and DHETs by the isotope ratio GC/MS method (26). Lung endothelial cells generate epoxygenase metabolites from endogenous precursors.…”

Section: Microvascular Endothelial Cells Express Cyp2c Isoformsmentioning

confidence: 99%

“…The medium was mixed with 10 ng each of 1-14 C-labeled DHETs (55 Ci/mol; 95 atom % enrichment in 14 C) or 1-14 C-labeled EETs (55 Ci/mol) and extracted with ethyl acetate. The EETs and DHETs present in the culture medium were purified by reversed-phase HPLC (25), converted to the corresponding pentafluorobenzylesters (EETs) or pentafluorobenzylester-trimethylsilylether derivatives, and quantified by NICI/GC/MS exactly as described (26). The cell pellets were suspended in PBS, mixed with 10 ng each of 1-14 C-labeled EETs and DHETs (55 Ci/mol), and extracted with CHCl 3 /CH 3 OH (2:1).…”

Section: Synthesis Of Eets By Endothelialmentioning

confidence: 99%

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Characterization of 5,6- and 8,9-Epoxyeicosatrienoic Acids (5,6- and 8,9-EET) as Potent in Vivo Angiogenic Lipids

Pozzi¹,

Macias‐Perez²,

Abair³

et al. 2005

Journal of Biological Chemistry

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163

204

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The cytochrome P450 arachidonic acid epoxygenase metabolites, the epoxyeicosatrienoic acids (EETs) are powerful, nonregioselective, stimulators of cell proliferation. In this study we compared the ability of the four EETs (5,6-, 8,9-, 11,12-, and 14,15-EETs) to regulate endothelial cell proliferation in vitro and angiogenesis in vivo and determined the molecular mechanism by which EETs control these events. Inhibition of the epoxygenase blocked serum-induced endothelial cell proliferation, and exogenously added EETs rescued cell proliferation from epoxygenase inhibition. Studies with selective ERK, p38 MAPK, or PI3K inhibitors revealed that whereas activation of p38 MAPK is required for the proliferative responses to 8,9-and 11,12-EET, activation of PI3K is necessary for the cell proliferation induced by 5,6-and 14,15-EET. Among the four EETs, only 5,6-and 8,9-EET are capable of promoting endothelial cell migration and the formation of capillary-like structures, events that are dependent on EET-mediated activation of ERK and PI3K. Using subcutaneous sponge models, we showed that 5,6-and 8,9-EET are pro-angiogenic in mice and that their neo-vascularization effects are enhanced by the co-administration of an inhibitor of EET enzymatic hydration, presumably because of reduced EET metabolism and inactivation. These studies identify 5,6-and 8,9-EET as powerful and selective angiogenic lipids, provide a functional link between the EET proliferative chemotactic properties and their angiogenic activity, and suggest a physiological role for them in angiogenesis and de novo vascularization.

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“…20-Hydroxy-14,15-epoxyeicosatrienoic acid (HEET) was resolved from 20,11,12-and 20,8,9-HEETs by normal-phase HPLC on a 5-m Dynamax silica column (4.6 ϫ 250 cm; Rainin Instruments Co. Inc.) using a mixture of hexane/EtOH/HOAc (98:2:0.1) at a flow rate of 1.5 ml/min. For structural analysis, the reaction products were collected from the RP-HPLC eluents and derivatized to the corresponding methyl or pentafluorobenzyl ester, trimethylsilyl ether derivatives (30). Silylations were done using bis(trimethylsilyl)trifluoroacetamide (30).…”

Section: Chemicals-carbaprostacyclinmentioning

confidence: 99%

The CYP4A Isoforms Hydroxylate Epoxyeicosatrienoic Acids to Form High Affinity Peroxisome Proliferator-activated Receptor Ligands

Cowart

Wei²,

Hsu

et al. 2002

Journal of Biological Chemistry

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178

152

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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 -carbon. Analysis of cis-parinaric acid displacement from the ligand-binding domain of the human peroxisome proliferator-activated receptor-␣ showed that -hydroxylated 14,15-EET bound to this receptor with high affinity (K i ‫؍‬ 3 ؎ 1 nM). Moreover, at 1 M, the -alcohol of 14,15-EET or a 1:4 mixture of the -alcohols of 8,9-and 11,12-EETs activated human and mouse peroxisome proliferator-activated receptor-␣ in transient transfection assays, suggesting a role for them as endogenous ligands for these orphan nuclear receptors.Cytochromes P450 of the CYP4A gene subfamily are structurally and functionally conserved fatty-acid hydroxylases that are expressed in most mammalian tissues, including rat and human kidney and liver (1-7). These enzymes are selective for the /-1-hydroxylation of saturated and unsaturated fatty acids (1-7) and lack known roles in drug metabolism. The expression of some CYP4A isoforms is under the control of the peroxisome proliferator-activated receptor-␣ (PPAR␣) 1 (8 -13) and regulated by a variety of physiological and pathophysiological stimuli, including dietary fatty acids, hormones, diabetes, and starvation (9 -13). Interest in the molecular and functional properties of these enzymes has been stimulated by the demonstration of their role in the /-1-hydroxylation of arachidonic acid (AA) (4 -7) and the powerful biological activities of 19-and 20-hydroxyeicosatetraenoic acids (HETEs) as modulators of renal ion fluxes and vasoactivity (14 -18). Based on biochemical and functional correlates of CYP4A renal expression, 20-HETE biosynthesis, and the onset of systemic high blood pressure in the SHR/WKY rat model of spontaneous hypertension, a pro-hypertensive role for 20-HETE and CYP4A isoforms was proposed (14).The cytochrome P450 AA epoxygenase catalyzes the in vivo regio-and enantioselective metabolism of AA to epoxyeicosatrienoic acids (EETs) (16). Studies with microsomal and/or purified cytochrome P450 preparations showed tha...

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[42] Cytochrome P450 arachidonic acid epoxygenase: Stereochemical characterization of epoxyeicosatrienoic acids

Cited by 73 publications

References 11 publications

IGF‐1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging

IGF‐1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging

Characterization of 5,6- and 8,9-Epoxyeicosatrienoic Acids (5,6- and 8,9-EET) as Potent in Vivo Angiogenic Lipids

The CYP4A Isoforms Hydroxylate Epoxyeicosatrienoic Acids to Form High Affinity Peroxisome Proliferator-activated Receptor Ligands

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