Synergistic effect of cytochrome P450 epoxygenase CYP2J2*7 polymorphism with smoking on the onset of premature myocardial infarction

CYP2J2-mediated metabolism of arachidonic acid in heart: A review of its kinetics, inhibition and role in heart rhythm control

Cytochrome P450 2 J2 (CYP2J2) is primarily expressed extrahepatically and is the predominant epoxygenase in human cardiac tissues. This highlights its key role in the metabolism of endogenous substrates. Significant scientific interest lies in cardiac CYP2J2 metabolism of arachidonic acid (AA), an omega-6 polyunsaturated fatty acid, to regioisomeric bioactive epoxyeicosatrienoic acid (EET) metabolites that show cardioprotective effects including regulation of cardiac electrophysiology. From an in vitro perspective, the accurate characterization of the kinetics of CYP2J2 metabolism of AA including its inhibition and inactivation by drugs could be useful in facilitating in vitro-in vivo extrapolations to predict drug-AA interactions in drug discovery and development. In this review, background information on the structure, regulation and expression of CYP2J2 in human heart is presented alongside AA and EETs as its endogenous substrate and metabolites. The in vitro and in vivo implications of the kinetics of this endogenous metabolic pathway as well as its perturbation via inhibition and inactivation by drugs are elaborated. Additionally, the role of CYP2J2-mediated metabolism of AA to EETs in cardiac electrophysiology will be expounded.

COX-2/sEH-Mediated Macrophage Activation Is a Target for Pulmonary Protection in Mouse Models of Chronic Obstructive Pulmonary Disease

Effective inhibition of macrophage activation is critical for resolving inflammation and restoring pulmonary function in patients with chronic obstructive pulmonary disease (COPD). In this study, we identified the dual-enhanced cyclooxygenase-2 (COX-2)/soluble epoxide hydrolase (sEH) as a novel regulator of macrophage activation in COPD. Both COX-2 and sEH were found to be increased in patients and mice with COPD and in macrophages exposed to cigarette smoke extract. Pharmacological reduction of the COX-2 and sEH by 4-(5-phenyl-3-{3-[3-(4-trifluoromethylphenyl)-ureido]-propyl}-pyrazol-1-yl)-benzenesulfonamide (PTUPB) effectively prevented macrophage activation, downregulated inflammation-related genes, and reduced lung injury, thereby improving respiratory function in a mouse model of COPD induced by cigarette smoke and lipopolysaccharide. Mechanistically, enhanced COX-2/sEH triggered the activation of the NACHT, LRR, and PYD domains-containing protein 3 inflammasome, leading to the cleavage of pro-IL-1β into its active form in macrophages and amplifying inflammatory responses. These findings demonstrate that targeting COX-2/sEH-mediated macrophage activation may be a promising therapeutic strategy for COPD. Importantly, our data support the potential use of the dual COX-2 and sEH inhibitor PTUPB as a therapeutic drug for the treatment of COPD.

Characterization of 15 CYP2J2 variants identified in the Chinese Han population on the metabolism of ebastine and terfenadine in vitro

Genetic polymorphism of the cytochrome P450 (CYP) gene can significantly influence the metabolism of endogenous and xenobiotic compounds. However, few studies have focused on the polymorphism of CYP2J2 and its impact on drug catalytic activity, especially in the Chinese Han population. In this study, we sequenced the promoter and exon regions of CYP2J2 in 1,163 unrelated healthy Chinese Han individuals using the multiplex PCR amplicon sequencing method. Then, the catalytic activities of the detected CYP2J2 variants were evaluated after recombinant expression in S. cerevisiae microsomes. As a result, CYP2J2*7, CYP2J2*8, 13 variations in the promoter region and 15 CYP2J2 nonsynonymous variants were detected, of which V15A, G24R, V68A, L166F and A391T were novel missense variations. Immunoblotting results showed that 11 of 15 CYP2J2 variants exhibited lower protein expression than wild-type CYP2J2.1. In vitro functional analysis results revealed that the amino acid changes of 14 variants could significantly influence the drug metabolic activity of CYP2J2 toward ebastine or terfenadine. Specifically, 4 variants with relatively higher allele frequencies, CYP2J2.8, 173_173del, K267fs and R446W, exhibited extremely low protein expression and defective catalytic activities for both substrates. Our results indicated that a high genetic polymorphism of CYP2J2 could be detected in the Chinese Han population, and most genetic variations in CYP2J2 could influence the expression and catalytic activity of CYP2J2. Our data significantly enrich the knowledge of genetic polymorphisms in CYP2J2 and provide new theoretical information for corresponding individualized medication in Chinese and other Asian populations.

Crosstalk between adenosine receptors and CYP450-derived oxylipins in the modulation of cardiovascular, including coronary reactive hyperemic response

Adenosine is a ubiquitous endogenous nucleoside or autacoid that affects the cardiovascular system through the activation of four G-protein coupled receptors: adenosine A₁ receptor (A₁AR), adenosine A_2A receptor (A_2AAR), adenosine A_2B receptor (A_2BAR), and adenosine A₃ receptor (A₃AR). With the rapid generation of this nucleoside from cellular metabolism and the widespread distribution of its four G-protein coupled receptors in almost all organs and tissues of the body, this autacoid induces multiple physiological as well as pathological effects, not only regulating the cardiovascular system but also the central nervous system, peripheral vascular system, and immune system. Mounting evidence shows the role of CYP450-enzymes in cardiovascular physiology and pathology, and the genetic polymorphisms in CYP450s can increase susceptibility to cardiovascular diseases (CVDs). One of the most important physiological roles of CYP450-epoxygenases (CYP450-2C & CYP2J2) is the metabolism of arachidonic acid (AA) and linoleic acid (LA) into epoxyeicosatrienoic acids (EETs) and epoxyoctadecaenoic acid (EpOMEs) which generally involve in vasodilation. Like an increase in coronary reactive hyperemia (CRH), an increase in anti-inflammation, and cardioprotective effects. Moreover, the genetic polymorphisms in CYP450-epoxygenases will change the beneficial cardiovascular effects of metabolites or oxylipins into detrimental effects. The soluble epoxide hydrolase (sEH) is another crucial enzyme ubiquitously expressed in all living organisms and almost all organs and tissues. However, in contrast to CYP450-epoxygenases, sEH converts EETs into dihydroxyeicosatrienoic acid (DHETs), EpOMEs into dihydroxyoctadecaenoic acid (DiHOMEs), and others and reverses the beneficial effects of epoxy-fatty acids leading to vasoconstriction, reducing CRH, increase in pro-inflammation, increase in pro-thrombotic and become less cardioprotective. Therefore, polymorphisms in the sEH gene (Ephx2) cause the enzyme to become overactive, making it more vulnerable to CVDs, including hypertension. Besides the sEH, ω-hydroxylases (CYP450-4A11 & CYP450-4F2) derived metabolites from AA, ω terminal-hydroxyeicosatetraenoic acids (19-, 20-HETE), lipoxygenase-derived mid-chain hydroxyeicosatetraenoic acids (5-, 11-, 12-, 15-HETEs), and the cyclooxygenase-derived prostanoids (prostaglandins: PGD₂, PGF_2α; thromboxane: Txs, oxylipins) are involved in vasoconstriction, hypertension, reduction in CRH, pro-inflammation and cardiac toxicity. Interestingly, the interactions of adenosine receptors (A_2AAR, A₁AR) with CYP450-epoxygenases, ω-hydroxylases, sEH, and their derived metabolites or oxygenated polyunsaturated fatty acids (PUFAs or oxylipins) is shown in the regulation of the cardiovascular functions. In addition, much evidence demonstrates polymorphisms in CYP450-epoxygenases, ω-hydroxylases, and sEH genes (Ephx2) and adenosine receptor genes (ADORA1 & ADORA2) in the human population with the susceptibility to CVDs, including hypertension. CVDs are the number one cause of death globally, coronary artery disease (CAD) was the leading cause of death in the US in 2019, and hypertension is one of the most potent causes of CVDs. This review summarizes the articles related to the crosstalk between adenosine receptors and CYP450-derived oxylipins in vascular, including the CRH response in regular salt-diet fed and high salt-diet fed mice with the correlation of heart perfusate/plasma oxylipins. By using A_2AAR^-/-, A₁AR^-/-, eNOS^-/-, sEH^-/- or Ephx2^-/-, vascular sEH-overexpressed (Tie2-sEH Tr), vascular CYP2J2-overexpressed (Tie2-CYP2J2 Tr), and wild-type (WT) mice. This review article also summarizes the role of pro-and anti-inflammatory oxylipins in cardiovascular function/dysfunction in mice and humans. Therefore, more studies are needed better to understand the crosstalk between the adenosine receptors and eicosanoids to develop diagnostic and therapeutic tools by using plasma oxylipins profiles in CVDs, including hypertensive cases in the future.

Cardiomyocyte-specific CYP2J2 and its therapeutic implications

INTRODUCTION

Cytochrome P450s (CYPs) are a superfamily of monooxygenases with diverse biological roles. CYP2J2 is an isozyme highly expressed in the heart where it metabolizes endogenous substrates such as N-3/N-6 polyunsaturated fatty acids (PUFA) to produce lipid mediators involved in homeostasis and cardioprotective responses. Expanding our knowledge of the role CYP2J2 has within the heart is important for understanding its impact on cardiac health and disease.

AREAS COVERED

The objective of this review was to assess the state of knowledge regarding cardiac CYP2J2. A literature search was conducted using PubMed-MEDLINE (from 2022 and earlier) to evaluate relevant studies regarding CYP2J2 mediated cardioprotection, small molecule modulators, effects of CYP2J2 substrates toward biologically relevant effects and implications of CYP2J2 polymorphisms and sexual dimorphism in the heart.

EXPERT OPINION

Cardiac CYP2J2-mediated metabolism of endogenous and exogenous substrates have been shown to impact cardiac function. Identifying individual factors, like sex and age, that affect CYP2J2 require further elucidation to better understand CYP2J2's clinical relevance. Resolving the biological targets and activities of CYP2J2-derived PUFA metabolites will be necessary to safely target CYP2J2 and design novel analogues. Targeting CYP2J2 for therapeutic aims offers a potential novel approach to regulating cardiac homeostasis, drug metabolism and cardioprotection.

Site-directed deuteration of dronedarone preserves cytochrome P4502J2 activity and mitigates its cardiac adverse effects in canine arrhythmic hearts

Cytochrome P4502J2 (CYP2J2) metabolizes arachidonic acid (AA) to cardioprotective epoxyeicosatrienoic acids (EETs). Dronedarone, an antiarrhythmic drug prescribed for treatment of atrial fibrillation (AF) induces cardiac adverse effects (AEs) with poorly understood mechanisms. We previously demonstrated that dronedarone inactivates CYP2J2 potently and irreversibly, disrupts AA-EET pathway leading to cardiac mitochondrial toxicity rescuable via EET enrichment. In this study, we investigated if mitigation of CYP2J2 inhibition prevents dronedarone-induced cardiac AEs. We first synthesized a deuterated analogue of dronedarone (termed poyendarone) and demonstrated that it neither inactivates CYP2J2, disrupts AA-EETs metabolism nor causes cardiac mitochondrial toxicity in vitro. Our patch-clamp experiments demonstrated that pharmacoelectrophysiology of dronedarone is unaffected by deuteration. Next, we show that dronedarone treatment or CYP2J2 knockdown in spontaneously beating cardiomyocytes indicative of depleted CYP2J2 activity exacerbates beat-to-beat (BTB) variability reflective of proarrhythmic phenotype. In contrast, poyendarone treatment yields significantly lower BTB variability compared to dronedarone in cardiomyocytes indicative of preserved CYP2J2 activity. Importantly, poyendarone and dronedarone display similar antiarrhythmic properties in the canine model of persistent AF, while poyendarone substantially reduces beat-to-beat variability of repolarization duration suggestive of diminished proarrhythmic risk. Our findings prove that deuteration of dronedarone prevents CYP2J2 inactivation and mitigates dronedarone-induced cardiac AEs.

ROS-responsive nanoparticle-mediated delivery of CYP2J2 gene for therapeutic angiogenesis in severe hindlimb ischemia

With critical limb ischemia (CLI) being a multi-factorial disease, it is becoming evident that gene therapy with a multiple bio-functional growth factor could achieve better therapeutic outcomes. Cytochrome P450 epoxygenase-2J2 (CYP2J2) and its catalytic products epoxyeicosatrienoic acids (EETs) exhibit pleiotropic biological activities, including pro-angiogenic, anti-inflammatory and cardiovascular protective effects, which are considerably beneficial for reversing ischemia and restoring local blood flow in CLI. Here, we designed a nanoparticle-based pcDNA3.1-CYP2J2 plasmid DNA (pDNA) delivery system (nanoparticle/pDNA complex) composed of a novel three-arm star block copolymer (3S-PLGA-po-PEG), which was achieved by conjugating three-armed PLGA to PEG via the peroxalate ester bond. Considering the multiple bio-functions of CYP2J2-EETs and the sensitivity of the peroxalate ester bond to H₂O₂, this nanoparticle-based gene delivery system is expected to exhibit excellent pro-angiogenic effects while improving the high oxidative stress and inflammatory micro-environment in ischemic hindlimb. Our study reports the first application of CYP2J2 in the field of therapeutic angiogenesis for CLI treatment and our findings demonstrated good biocompatibility, stability and sustained release properties of the CYP2J2 nano-delivery system. In addition, this nanoparticle-based gene delivery system showed high transfection efficiency and efficient VEGF expression in vitro and in vivo. Intramuscular injection of nanoparticle/pDNA complexes into mice with hindlimb ischemia resulted in significant rapid blood flow recovery and improved muscle repair compared to mice treated with naked pDNA. In summary, 3S-PLGA-po-PEG/CYP2J2-pDNA complexes have tremendous potential and provide a practical strategy for the treatment of limb ischemia. Moreover, 3S-PLGA-po-PEG nanoparticles might be useful as a potential non-viral carrier for other gene delivery applications.

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Cytochrome P450 epoxygenase-2J2 (CYP2J2) was first applied in the field of therapeutic angiogenesis for critical limb ischemia treatment.

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The ROS-responsive three-arm star block copolymer (3S-PLGA-po-PEG) was synthesized with peroxalate ester as H₂O₂-responsive linkages through the esterification reaction of oxalyl chloride and hydroxyl group.

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The CYP2J2 nano-delivery system achieved high transfection efficiency and significant therapeutic angiogenesis effect.

Genetics Variants in the Epoxygenase Pathway of Arachidonic Metabolism Are Associated with Eicosanoids Levels and the Risk of Diabetic Nephropathy

Genes in the epoxygenase pathway of arachidonic acid metabolism leading to vasoactive eicosanoids, mainly 20-hydroxyeicosatetraenoic (20-HETE) and epoxyeicosatrienoic (EETs) acids, have been related to glucose-induced renal damage in preclinical reports. We genotyped 1088 diabetic kidney disease (DKD) patients and controls for seven polymorphisms in five genes (CYP2C8, CYP2J2, CYP4F2, CYP4A11, and EPHX2) along this metabolic route and evaluated their effect on DKD risk, clinical outcomes, and the plasma/urine levels of eicosanoids measured by LC/MS/MS and immunoenzymatic assays. The CYP4F2 433M variant allele was associated with lower incidence of DKD (OR = 0.65 (0.48-0.90), p = 0.008), whilst the CYP2C8*3/*3 genotype was related to increased risk (OR = 3.21 (1.05-9.87), p = 0.036). Patients carrying the 433M allele also showed lower eGFR [median and interquartile range vs. wildtype carriers: 30.8 (19.8) and 33.0 (23.2) mL/min/1.73 m², p = 0.037). Finally, the 433VM/MM variant genotypes were associated with lower urinary levels of 20-HETE compared with 433VV (3.14 (0.86) vs. 8.45 (3.69) ng/mg Creatinine, p = 0.024). Our results indicate that the CYP4F2 V433M polymorphism, by decreasing 20-HETE levels, may play an important role in DKD.

Soluble epoxide hydrolase deletion attenuated nicotine-induced arterial stiffness via limiting the loss of SIRT1

Arterial stiffness, a consequence of smoking, is an underlying risk factor of cardiovascular diseases. Epoxyeicosatrienoic acids (EETs), hydrolyzed by soluble epoxide hydrolase (sEH), have beneficial effects against vascular dysfunction. However, the role of sEH knockout in nicotine-induced arterial stiffness was not characterized. We hypothesized that sEH knockout could prevent nicotine-induced arterial stiffness. In the present study, Ephx2 (the gene encodes sEH enzyme) null (Ephx2^-/-) mice and wild-type (WT) littermate mice were infused with or without nicotine and administered with or without nicotinamide [NAM, sirtuin-1 (SIRT1) inhibitor] simultaneously for 4 wk. Nicotine treatment increased sEH expression and activity in the aortas of WT mice. Nicotine infusion significantly induced vascular remodeling, arterial stiffness, and SIRT1 deactivation in WT mice, which was attenuated in Ephx2 knockout mice (Ephx2^-/- mice) without NAM treatment. However, the arterial protective effects were gone in Ephx2^-/- mice with NAM treatment. In vitro, 11,12-EET treatment attenuated nicotine-induced matrix metalloproteinase 2 (MMP2) upregulation via SIRT1-mediated yes-associated protein (YAP) deacetylation. In conclusion, sEH knockout attenuated nicotine-induced arterial stiffness and vascular remodeling via SIRT1-induced YAP deacetylation.NEW & NOTEWORTHY We presently show that sEH knockout repressed nicotine-induced arterial stiffness and extracellular matrix remodeling via SIRT1-induced YAP deacetylation, which highlights that sEH is a potential therapeutic target in smoking-induced arterial stiffness and vascular remodeling.

Association of Arachidonic Acid-derived Lipid Mediators with Subsequent Onset of Acute Myocardial Infarction in Patients with Coronary Artery Disease

Polyunsaturated fatty acids (PUFAs) have been suggested for cardiovascular health. This study was conducted to investigate the prognostic impacts of the PUFA metabolites, oxylipins, on clinical outcomes in coronary artery disease (CAD). A total of 2,239 patients with stable CAD were prospectively enrolled and followed up regularly. Among them, twenty-five consecutive patients with new onset of acute myocardial infarction (AMI) within 2-year follow-up were studied. Another 50 gender- and age-matched patients without clinical cardiovascular events for more than 2 years were studied for control. Baseline levels of specific arachidonic acid metabolites were significantly higher in patients with subsequent AMI than in the controls. In Kaplan-Meier analysis, the incidence of future AMI was more frequently seen in patients with higher baseline levels of 8-hydroxyeicosatetraenoic acid (HETE), 9-HETE, 11-HETE, 12-HETE, 15-HETE, 19-HETE, 20-HETE, 5,6-epoxyeicosatrienoic acid (EET), 8,9-EET, 11,12-EET, or 14-15-EET when compared to their counterparts (all the P < 0.01). Further, serum levels of these specific HETEs, except for 11,12-EET, were positively correlated to the levels of some inflammatory and cardiac biomarker such as tumor necrosis factor-α and N-terminal pro B-type natriuretic peptide. Accordingly, serum specific oxylipins levels are increased and associated with the consequent onset of AMI, suggesting their potential role for secondary prevention in clinically stable CAD.

Role of cytochrome P450-derived, polyunsaturated fatty acid mediators in diabetes and the metabolic syndrome

Over the last decade, cases of metabolic syndrome and type II diabetes have increased exponentially. Exercise and ω-3 polyunsaturated fatty acid (PUFA)-enriched diets are usually prescribed but no therapy is effectively able to restore the impaired glucose metabolism, hypertension, and atherogenic dyslipidemia encountered by diabetic patients. PUFAs are metabolized by different enzymes into bioactive metabolites with anti- or pro-inflammatory activity. One important class of PUFA metabolizing enzymes are the cytochrome P450 (CYP) enzymes that can generate a series of bioactive products, many of which have been attributed protective/anti-inflammatory and insulin-sensitizing effects in animal models. PUFA epoxides are, however, further metabolized by the soluble epoxide hydrolase (sEH) to fatty acid diols. The biological actions of the latter are less well understood but while low concentrations may be biologically important, higher concentrations of diols derived from linoleic acid and docosahexaenoic acid have been linked with inflammation. One potential application for sEH inhibitors is in the treatment of diabetic retinopathy where sEH expression and activity is elevated as are levels of a diol of docosahexaenoic acid that can induce the destabilization of the retina vasculature.

Associations between CYP2J2 (-76G>T) rs890293 polymorphism and age-related macular degeneration

Backgroung. Age-related macular degeneration (AMD) is a disease of the macula, which significantly affects the eyesight and leads to irreversible central vision loss. The etiopathogenesis of AMD is still not absolutely clear. It is thought that age-related macular degeneration has a multifactorial etiology, the development of which may be caused by interrelation of environmental with innate factors, while genetic factors also have an impact. Macular degenerative changes occur due to the formation of drusen, about 40% of which is lipids. As the CYP2J2 gene is involved in the metabolism of lipids, it was selected for investigation in this study.

PURPOSE

To determine the relation between early stage and exudative AMD and CYP2J2 (-76G>T) gene rs890293 polymorphism in a Lithuanian population.

METHODS

The study enrolled 204 patients with early AMD, 197 patients with exudative AMD and 198 healthy controls. Samples of DNA from peripheral white blood cells were purified using commercial kits. The genotyping was carried out using a real-time PCR method.

RESULTS

The CYP2J2 (-76G>T) rs890293 TT genotype in patients with early AMD was statistically significantly less frequent than in the control group: 0% vs. 2.5% (P=0.028). There were no significant differences in rs890293 gene polymorphisms between the exudative AMD and control groups. Also, the CYP2J2 (-76G>T) rs890293 TT genotype was statistically significantly less frequent in older early AMD patients (≥65 years) compared to control group persons (≥65 years): 0% vs. 5.4% (P=0.03).

CONCLUSION

The CYP2J2 (-76G>T) TT genotype may be associated with reduced manifestation of early stage AMD; therefore, a larger sample size is required for further analysis.

A comprehensive study revealed SNP-SNP interactions and a sex-dependent relationship between polymorphisms of the CYP2J2 gene and hypertension risk

This study investigated whether common polymorphisms of cytochrome P450 2J2 (CYP2J2), a major enzyme that controls the biosynthesis of vasoactive epoxyeicosatrienoic acids, are collectively involved in the molecular basis of essential hypertension (EH). A total of 2314 unrelated Russian subjects from the Kursk (discovery sample: 913 EH patients and 645 controls) and Belgorod (replication sample: 345 EH patients and 411 controls) regions were recruited for this study. Eight single nucleotide polymorphisms (SNPs), including rs890293, rs11572182, rs10493270, rs1155002, rs2280275, rs7515289, rs11572325, and rs10889162, of CYP2J2 were genotyped using the MassARRAY 4 system and TaqMan-based assays. Significant associations were identified among the SNPs rs890293 (OR = 2.17, 95%CI 1.30-3.65), rs2280275 (OR = 1.59, 95%CI 1.10-2.37) and rs11572325 (OR = 1.89, 95%CI 1.22-2.95) and the risk of EH in females from the Kursk population. Sixteen CYP2J2 genotype combinations only showed significant associations with EH risk only in females. A common haplotype, T-T-G-C-C-C-T-A, increased the risk of EH in females. The bioinformatic analysis enabled identification of the SNPs that possess regulatory potential and/or are located within the binding sites for multiple transcription factors that play roles in the pathways involved in hypertension pathogenesis. Moreover, the polymorphisms rs890293, rs2280275, and rs11572325 were found to be significantly associated with hypertension risk in the Belgorod population. In conclusion, the rs2280275 and rs11572325 SNPs of CYP2J2 may be considered novel genetic markers of hypertension, at least in Russian women. However, sex-specific associations between CYP2J2 gene polymorphisms and hypertension require further investigation to clarify the specific genetic and/or environmental factors that are responsible for the increased disease susceptibility of women compared to that of men.

Role of cytochrome epoxygenase (CYP2J2) in the pathophysiology of coronary artery disease in South Indian population

Background

The cytochrome P-450 2J2 (CYP2J2) is known to be one of the major enzymes of epoxygenase pathway of arachidonic acid in extrahepatic tissues, which produces series of regioisomeric cis-epoxyeicosatrienoic acids (EETs) such as 5,6-, 8,9-, 11,12-, and 14,15-EETs. In the present study, we analyzed the impact of a genetic variant in CYP2J2 on coronary artery disease (CAD) in the Telangana region of Indian population.

Material and methods

The case–control study consisted of 100 CAD cases and 110 healthy controls. The deoxyribonucleic acid was extracted using the salting out method. Genotyping and gene expression was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism and real-time-PCR methods.

Results

In the present study, the percentage of smokers, alcoholics, hypertensive patients, and diabetics was high. Increase in fasting glucose, urea, creatinine, fasting triglycerides, total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), total cholesterol/high-density lipoprotein (TC/HDL), LDL/HDL, homocysteine, and C-reactive protein levels were significantly higher in patients with CAD than in controls (p < 0.001). CYP2J2 G-50T was associated with CAD (p = 0.04). The mRNA expression of CYP2J2 showed altered gene expression in this study among CAD patients in comparison with control (p = 0.01).

Conclusions

A functionally relevant polymorphism of the CYP2J2 gene was independently associated with an increased risk of CAD.

Genetic polymorphisms of the drug-metabolizing enzyme CYP2J2 in a Tibetan population

As an important metabolic enzyme, it is necessary to investigate the genetic polymorphisms of CYP2J2 among healthy Tibetan individuals. Genetic polymorphisms of CYP2J2 could affect enzyme activity and lead to differences among individual responses to drugs.We sequenced the whole gene of CYP2J2 in 100 unrelated, healthy Tibetan volunteers from the Tibet Autonomous Region and screened for genetic variants in the promoters, introns, exons, and the 3'-UTR regions.We detected 4 novel genetic polymorphisms of the CYP2J2 gene. The allelic frequencies of CYP2D6*1 and *7 were 0.955 and 0.045, respectively. CYP2D6*1/*7 decreased the activity of CYP2J2 and was expressed in 9% of the sample population.Our results provided basic data about CYP2J2 polymorphisms in a Tibetan population, suggested that the enzymatic activities of CYP2J2 might be different within the ethnic group, and offered a theoretical basis for individualized medical treatment and drug genomics studies.

Regulation of CYP2J2 and EET Levels in Cardiac Disease and Diabetes

Cytochrome P450 2J2 (CYP2J2) is a known arachidonic acid (AA) epoxygenase that mediates the formation of four bioactive regioisomers of cis-epoxyeicosatrienoic acids (EETs). Although its expression in the liver is low, CYP2J2 is mainly observed in extrahepatic tissues, including the small intestine, pancreas, lung, and heart. Changes in CYP2J2 levels or activity by xenobiotics, disease states, or polymorphisms are proposed to lead to various organ dysfunctions. Several studies have investigated the regulation of CYP2J2 and EET formation in various cell lines and have demonstrated that such regulation is tissue-dependent. In addition, studies linking CYP2J2 polymorphisms to the risk of developing cardiovascular disease (CVD) yielded contradictory results. This review will focus on the mechanisms of regulation of CYP2J2 by inducers, inhibitors, and oxidative stress modeling certain disease states in various cell lines and tissues. The implication of CYP2J2 expression, polymorphisms, activity and, as a result, EET levels in the pathophysiology of diabetes and CVD will also be discussed.

Polymorphisms in genes involved in vasoactive eicosanoid synthesis affect cardiovascular risk in renal transplant recipients

OBJECTIVE

Arachidonic acid metabolism by cytochrome P450 (CYP) epoxygenases leads to epoxyeicosatrienoic acids (EETs), which are eicosanoids with vasodilator and anti-inflammatory properties. We aim to determine whether genetic variability in these routes may contribute to cardiovascular (CV) risk in renal transplant recipients.

METHODS

In a cohort of 355 patients, we determined the presence of two polymorphisms, CYP2C8*3 and CYP2J2*7, known to affect eicosanoid levels. Associations with CV mortality, CV event-free long-term survival and graft survival were retrospectively investigated by logistic regression models.

RESULTS

CYP2J2*7 showed a statistical trend towards higher CV mortality (p = .06) and lower cardiac or cerebral event-free long-term survival (p = .05), whilst CYP2C8*3 displayed a significant inverse association with the risk of CV event (hazard ratio [HR] = 0.34 [0.15-0.78], p = .01). The association of CYP2J2*7 with CV mortality became significant when the analysis was restrained to 316 patients without a history of CV events prior to transplantation (HR = 15.72 [2.83-91.94], p = .005). In this subgroup of patients both single nucleotide polymorphisms (SNPs) were significantly associated with event-free survival. HR values were 5.44 (1.60-18.51), p = .007 and 0.26 (0.09-0.75), p = .012 for CYP2J2*7 and CYP2C8*3, respectively.

CONCLUSIONS

Our results show, for the first time to our knowledge, that two SNPs in CYP2C8 and CYP2J2, which synthesize EETs, may modify CV outcomes in renal transplant recipients, a population that is already at a high risk of suffering these events.

Multiplex quantitative analysis of eicosanoid mediators in human plasma and serum: Possible introduction into clinical testing

Eicosanoid mediators play important roles in maintaining the physiological and pathophysiological homeostasis in the body. Their measurements, however, are rarely performed in clinical practice. In the present study, we analyzed 30 varieties of eicosanoid mediators that were detectable in human plasma and serum collected from healthy donors, using liquid chromatography-tandem mass spectrometry from the viewpoint of the clinical application of the multiplex quantitation of eicosanoid mediators. Wider variety of eicosanoid mediators were detected in serum (27 out of 30) than in plasma (14 out of 30), since the serum was thought to contain lipid mediators released from activated platelets. Larger inter-individual variations were observed in the plasma and serum eicosanoid levels. On the other hand, the concentrations of eicosanoids were not affected by the platelet count but were affected by the concentration of arachidonic acid (AA) within the reference interval (17.4-40.5×10¹⁰/L). When serum samples from patients with hematological disorders were analyzed, the concentrations of AA were positively correlated with the platelet count. When the patients underwent ASA therapy, a marked decrease in the concentrations of thromboxane B₂ (TXB₂) and 12-hydroxyl-heptadecatrienoic acid (12-HHT) was observed. Considering the availability of serum samples in clinical settings, the serum analysis of eicosanoids may be clinically useful.

Meta-analysis of the association of the CYP2J2 G-50T polymorphism with coronary artery disease

The association of the CYP2J2 G-50T polymorphism with coronary artery disease has been explored, but the results remain controversial. Thus, a meta-analysis was conducted to provide a comprehensive estimate of this association. We selected ten articles encompassing 12 independent case-control studies with 7063 cases and 10,453 controls for this meta-analysis. Overall, we found significant associations between the CYP2J2 G-50T polymorphism and coronary artery disease risk in three genetic models (allele model: odds ratio (OR) = 1.19, 95% confidence interval (CI) = 1.05–1.34; homozygote model: OR = 2.25, 95% CI = 1.27–4.01; recessive model: OR = 2.17, 95% CI = 1.22–3.86). In these three genetic models, a significant association was observed in Caucasians but not in Asians when the data were stratified by ethnicity. However, no significant associations were found between the CYP2J2 polymorphism G-50T and coronary artery disease risk in heterozygote model and dominant model. In conclusion, our meta-analysis suggested that the CYP2J2 G-50T polymorphism was associated with coronary artery disease risk in the allele, homozygote and recessive models in Caucasians.

Association of CYP2J2 gene polymorphisms with ischemic stroke and stroke subtypes in Chinese population

BACKGROUND AND PURPOSE

Ischemic stroke (IS) is the main cause of mortality and disability among the old people in China and is a multifactorial disease influenced by many factors including genetic factors like the allele for CYP 2J2. It has been demonstrated that CYP2J2 polymorphisms alter the transcriptional activity. However, studies on the association between CYP2J2-50G/T polymorphism and IS have reported conflicting results. Thus, our study aimed to examine the association between 4 variants in the CYP2J2 gene and the risk of IS and its subtypes, in the Chinese population.

MATERIALS AND METHODS

In this study, genotyping was performed by using polymerase chain reaction (PCR) sequencing for 202 IS patients and 206 age- and sex-matched controls. Odds ratios (ORs) and confidence interval (CI) were estimated by multivariate logistic regression and PCR results were confirmed by DNA sequencing. A meta-analysis was conducted to evaluate the association of CYP2J2-50G>T polymorphism with the risk of IS in Chinese population by calculating pooled OR.

RESULTS

We found this polymorphism was significantly associated with IS (17.82% vs. 10.68%, P = 0.039). Multiple logistic regression analysis revealed that GT genotype was associated with a significantly high risk of IS (OR = 2.32, 95% CI: 1.21-4.45, P = 0. 011) after adjustment for other confounding factors such as hypertension, diabetes, heart disease, smoking habit, family history, triglyceride and low-density lipoprotein levels. We also found a significant association of GT genotype with small artery occlusion (SAA) (P < 0.05; OR = 2.22; 95% CI: 1.043-4.72). Meta-analysis results also showed that the GT genotype carriers had a negative effect on the risk of IS in Chinese population with overall OR of 1.40 (95% CI: 1.06-1.84).

CONCLUSION

The findings of the present study suggested that polymorphism in -50G/T position of CYP2J2 gene might be a risk factor for IS in Chinese population. Further large prospective studies were required to confirm these findings.

Mechanisms of Vascular Dysfunction in COPD and Effects of a Novel Soluble Epoxide Hydrolase Inhibitor in Smokers

Background

Smoking and COPD are risk factors for cardiovascular disease, and the pathogenesis may involve endothelial dysfunction. We tested the hypothesis that endothelium-derived epoxyeicosatrienoic acid (EET)-mediated endothelial function is impaired in patients with COPD and that a novel soluble epoxide hydrolase inhibitor, GSK2256294, attenuates EET-mediated endothelial dysfunction in human resistance vessels both in vitro and in vivo.

Methods

Endogenous and stimulated endothelial release of EETs was assessed in 12 patients with COPD, 11 overweight smokers, and two matched control groups, using forearm plethysmography with intraarterial infusions of fluconazole, bradykinin, and the combination. The effects of GSK2256294 on EET-mediated vasodilation in human resistance arteries were assessed in vitro and in vivo in a phase I clinical trial in healthy overweight smokers.

Results

Compared with control groups, there was reduced vasodilation with bradykinin (P = .005), a blunted effect of fluconazole on bradykinin-induced vasodilation (P = .03), and a trend toward reduced basal EET/dihydroxyepoxyeicosatrienoic acid ratio in patients with COPD (P = .08). A similar pattern was observed in overweight smokers. In vitro, 10 μM GSK2256294 increased 11,12-EET-mediated vasodilation compared with vehicle (90% ± 4.2% vs 72.6% ± 6.2% maximal dilatation) and shifted the bradykinin half-maximal effective concentration (EC50) (–8.33 ± 0.172 logM vs –8.10 ± 0.118 logM; P = .001 for EC50). In vivo, 18 mg GSK2256294 improved the maximum bradykinin response from 338% ± 46% before a dose to 566% ± 110% after a single dose (P = .02) and to 503% ± 123% after a chronic dose (P = .003).

Conclusions

GSK2256294 attenuates smoking-related EET-mediated endothelial dysfunction, suggesting potential therapeutic benefits in patients with COPD.

Trial Registry

ClinicalTrials.gov; No.: NCT01762774; URL: www.clinicaltrials.gov

Gene- gene interaction between CYP2J2 and PPAR -γ gene on late-onset Alzheimer's disease in the eastern Chinese Han population

AIMS

To investigate the impact of PPAR -γ and CYP2J2 gene single nucleotide polymorphisms (SNPs) and gene- gene interactions on late-onset Alzheimer's disease (LOAD) risk in Chinese Han population.

METHODS

A total of 880 participants (514 males, 366 females), with a mean age of 81.7±15.9years old are selected, including 430 LOAD patients and 450 normal participants. Generalized multifactor dimensionality reduction (GMDR) is used to examine interaction among six SNPs, odds ratio (OR) and 95% confident interval (95%CI) are calculated by Logistic regression model.

RESULTS

Logistic regression analysis showed that increased LOAD risks are associated with T allele of the rs1155002 polymorphism, adjusted OR (95%CI)=1.46 (1.12-1.90), and T allele of the rs890293 polymorphism, adjusted OR (95%CI)=1.65 (1.30-2.06), and G allele of the rs1805192 polymorphism, adjusted OR (95%CI)=1.70 (1.25-2.27). We also found a potential gene-gene interaction between rs890293 and rs1805192. Participants with GT or TT of rs890293 and CG or GG of rs1805192 genotype have the highest LOAD risk, compared to participants with GG of rs890293 and CC of rs1805192 genotype, OR (95%CI)=2.22 (1.63 -2.85), after covariates adjustment.

CONCLUSIONS

rs1155002, rs890293 and rs1805192 polymorphism are associated with increased LOAD risk. Participants with GT or TT of rs890293 and CG or GG of rs1805192 genotype have the highest LOAD risk.

Clinical Profile and Long-Term Prognostic Factors of a Young Chinese Han Population (≤ 40 Years) Having ST-Segment Elevation Myocardial Infarction

BACKGROUND

The proportion of the mainland Chinese population with premature ST-segment elevation myocardial infarction is significantly elevated. Young patients with ST-segment elevation myocardial infarction have a different risk factor profile and clinical outcome compared with elder patients, and may also differ as compared to young patients in Western populations.

METHODS

We analyzed a total of 9462 consecutive ST-segment elevation myocardial infarction patients, and recruited 341 consecutive cases who had survived their first ST-segment elevation myocardial infarction at the age less than 40 years, and followed-up these patients for 5 years.

RESULTS

The most prevalent risk factor in young Chinese ST-segment elevation myocardial infarction patients was smoking (307/341, 90.03%) and male gender (328/341, 96.19%), although young patients had fewer traditional risk factors of acute myocardial infarction than the control group [(1.63 ± 1.03) vs. (2.38 ± 1.15), p < 0.01]. The number of affected vessels in cases was significantly less than in the elder control group (p < 0.01). During the follow-up, blood lipids and blood pressure of most patients reached the target level, while 42.10% of patients reported continuation of smoking. Multivariable data analysis showed that persistence of smoking (OR: 3.784, 95% CI: 1.636-8.751, p < 0.01) was the most significant prognostic factor of cardiac events after adjusting for various confounding factors.

CONCLUSIONS

We demonstrated that cigarette smoking is the most prevalent factor among the avoidable cardiovascular risk factors for young ST-segment elevation myocardial infarctions in China. Accordingly, continued smoking is the most powerful predictor for the recurrence of cardiac events in young Chinese patients with ST-segment elevation myocardial infarction.

KEY WORDS

Premature myocardial infarction; Prognosis; Risk factor.

Polymorphisms in CYP-mediated arachidonic acid routes affect the outcome of renal transplantation

BACKGROUND

Arachidonic acid (AA) is metabolized by cytochrome P450 (CYP) enzymes to vasoactive metabolites (mainly epoxyeicosatrienoic acids) which are known to play a protective role against damaging processes that may occur after re-oxygenation of the graft. We aimed to investigate whether the presence of functional polymorphisms along these metabolic routes may play a role in the outcome of renal transplantation.

DESIGN

One-hundred and forty Caucasian renal transplant recipients and 137 donors were included. We determined the presence of seven common functional polymorphisms in the five genes governing the CYP-mediated AA metabolic pathway (CYP2C8, CYP2C9, CYP2J2, CYP4A11 and CYP4F2). Associations with parameters and events related to graft function and survival were retrospectively investigated throughout the first year after grafting.

RESULTS

The CYP2J2*7 allele of the donor was significantly associated with higher risk for delayed graft function [OR = 4·40 (1·45-13·37), P < 0·01] and lower death-censored graft survival [107·90 (84·19-131·62) vs. 176·89 (166·47-187·32) months for CYP2J2*1/*1 grafts; log-rank P = 0·015]. In addition, patients whose donors carried the CYP4A11 434S variant of the F434S polymorphism displayed impaired creatinine clearance, with statistically significant differences vs. 434FF subjects throughout the whole period of study (P < 0·05, P < 0·01, P < 0·001 and P < 0·05 for 1 week, 1 month, 5 months and 1 year after grafting, respectively).

CONCLUSIONS

Taken together, these results indicate that variability in the CYP450 genes involved in the synthesis of eicosanoids from AA may have a significant impact on graft function and survival in renal transplantation.

Gender-Specific Effect of CYP2C8*3 on the Risk of Essential Hypertension in Bulgarian Patients

We conducted a case-control study to determine the contribution of polymorphisms in CYP2C8 (CYP2C8*3) and CYP2J2 (CYP2J2*7) to increased risk of coronary artery disease and essential hypertension in Bulgarians. The current analysis included 192 unrelated hypertensive patients, 261 patients with angiographically documented CAD (153 with myocardial infarction and 108 without myocardial infarction), and 496 population controls. The CYP2C8*3 and CYP2J2*7 polymorphisms were genotyped by TaqMan SNP Genotyping Assay. PLINK version 1.07 was used for the statistical analysis. No overall association was observed for the studied polymorphisms with coronary artery disease and essential hypertension. The frequency of -50T mutant allele of CYP2J2*7 was significantly higher in male with coronary artery disease without history of myocardial infarction (OR 2.16 95% CI 1.04-4.48 p = 0.035) compared to population control group, but this association did not survive after Bonferroni correction (p adj = 0.07). A significant association of CYP2C8*3 allele with increased risk of essential hypertension has found in men (OR 2.12 95% CI 1.18-3.81 p = 0.015) and this relationship remained significant after adjustment for multiple comparisons (p adj = 0.03). This is the first study showing significant gene-sex interaction for CYP2C8*3 with twofold increase in the relative risk of essential hypertension and a similar tendency for CYP2J2*7 associated with coronary artery disease without myocardial infarction in Bulgarian males. The association is not seen in females and in the whole group of patients. This result could be partly explained by the effect of estrogens on the vascular tone of coronary arteries and CYP2C8 gene expression.

The role of epoxyeicosatrienoic acids in the cardiovascular system

There is increasing evidence suggesting that epoxyeicosatrienoic acids (EETs) play an important role in cardioprotective mechanisms. These include regulating vascular tone, modulating inflammatory responses, improving cardiomyocyte function and reducing ischaemic damage, resulting in attenuation of animal models of cardiovascular risk factors. This review discusses the current knowledge on the role of EETs in endothelium-dependent control of vascular tone in the healthy and in subjects with cardiovascular risk factors, and considers the pharmacological potential of targeting this pathway.

CYP2J2 rs890293 polymorphism is associated with susceptibility to Alzheimer's disease in the Chinese Han population

Alzheimer's disease (AD) is a common neurodegenerative disorder characterized by progressive cognitive dysfunction and memory loss. Increasing evidence indicates that inflammation in the brain is a powerful factor in AD progression. Epoxyeicosatrienoic acids, the biologically active derivatives of arachidonic acid, synthesized by cytochrome P450 (CYP) epoxygenases, have been proven to have powerful anti-inflammatory effects. The aim of this study was to examine whether polymorphism in CYP2J2, encoding one of the most common CYP epoxygenase isoforms, is associated with late-onset AD (LOAD). This case-control study genotyped 672 representatives of the Chinese Han population, including 321 LOAD patients and 351 healthy controls matched for age and gender, for the functional rs890293 polymorphism within CYP2J2 by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The CYP2J2 rs890293 T allele and GT+TT genotype were significantly associated with an increased risk of LOAD. Further data stratification according to the presence of the apolipoprotein E (APOE) e4 allele confirmed a strong association between CYP2J2 rs890293 and LOAD, and indicated that the involvement of CYP2J2 in LOAD was independent of ApoE-ϵ4. Our study demonstrated that CYP2J2 rs890293 is a possible predisposing genetic factor for progression of LOAD.

Epoxyeicosatrienoic acids and cardioprotection: the road to translation

Cardiovascular disease, including acute myocardial infarction (AMI), is the leading cause of morbidity and mortality globally, despite well-established treatments. The discovery and development of novel therapeutics that prevent the progression of devastating consequences following AMI are thus important in reducing the global burden of this devastating disease. Scientific evidence for the protective effects of epoxyeicosatrienoic acids (EETs) in the cardiovascular system is rapidly emerging and suggests that promoting the effects of these cytochrome P450-derived epoxyeicosanoids is a potentially viable clinical therapeutic strategy. Through a translational lens, this review will provide insight into the potential clinical utility of this therapeutic strategy for AMI by 1) outlining the known cardioprotective effects of EETs and underlying mechanisms demonstrated in preclinical models of AMI with a particular focus on myocardial ischemia-reperfusion injury, 2) describing studies in human cohorts that demonstrate a relationship between EETs and associated pathways with coronary artery disease risk, and 3) discussing preclinical and clinical areas that require further investigation in order to increase the probability of successfully translating this rapidly emerging body of evidence into a clinically applicable therapeutic strategy for AMI.

Cytochrome P450 2J2: distribution, function, regulation, genetic polymorphisms and clinical significance

Cytochrome P450 2J2 (CYP2J2) is an enzyme mainly found in human extrahepatic tissues, with predominant expression in the cardiovascular systems and lower levels in the intestine, kidney, lung, pancreas, brain, liver, etc. During the past 15 years, CYP2J2 has attracted much attention for its epoxygenase activity in arachidonic acid (AA) metabolism. It converts AA to four epoxyeicosatrienoic acids (EETs) that have various biological effects, especially in the cardiovascular systems. In recent publications, CYP2J2 is shown highly expressed in various human tumor cells, and its EET metabolites are demonstrated to implicate in the pathologic development of human cancers. CYP2J2 is also a human CYP that involved in phase I xenobiotics metabolism. Antihistamine drugs and many other compounds were identified as the substrates of CYP2J2, and studies have demonstrated that these substrates have a broad structural diversity. CYP2J2 is found not readily induced by known P450 inducers; however, its expression could be regulated in some pathological conditions, might through the activator protein-1(AP-1), the AP-1-like element and microRNA let-7b. Several genetic mutations in the CYP2J2 gene have been identified in humans, and some of them have been shown to have potential associations with some diseases. With the increasing awareness of its roles in cancer disease and drug metabolism, studies about CYP2J2 are still going on, and various inhibitors of CYP2J2 have been determined. Further studies are needed to delineate the roles of CYP2J2 in disease pathology, drug development and clinical practice.

Cytochrome P450 and ischemic heart disease: current concepts and future directions

INTRODUCTION

The P450 enzymes (P450s) mediate the biotransformation of several drugs, steroid hormones, eicosanoids, cholesterol, vitamins, fatty acids and bile acids, many of which affect cardiovascular homeostasis. Experimental studies have demonstrated that several P450s modulate important steps in the pathogenesis of ischemic heart disease (IHD).

AREAS COVERED

This article discusses the current knowledge on i) the expression of P450s in cardiovascular and renal tissues; ii) the role of P450s in the pathophysiology of IHD, in particular the modulation of blood pressure and cardiac hypertrophy, coronary arterial tone, ischemia-reperfusion injury and the metabolism of cardiovascular drugs; iii) the available evidence from observational studies on the association between P450 gene polymorphisms and risk of myocardial infarction (MI); and iv) suggestions for further research in this area.

EXPERT OPINION

P450s exert important modulatory effects in experimental models of IHD and MI. However, observational studies have provided conflicting results on the association between P450 genetic polymorphisms and MI. Further, adequately powered studies are required to ascertain the biological and clinical impact of P450s on clinical IHD end-points, that is, fatal and nonfatal MI, revascularization and long-term outcomes post MI. Pharmacogenetic substudies of recently completed cardiovascular clinical trials might represent an alternative strategy in this context.

Functional characterization of TLR4 +3725 G/C polymorphism and association with protection against overweight

Subclinical low-grade systemic inflammation has been associated with obesity, insulin resistance and metabolic syndrome (MS). Recent studies have highlighted the role of gut microbiota in these disorders. The toll-like receptor 4 (TLR4) plays a key role in the innate immune response activation. We studied two polymorphisms (+3725G/C and 11350G/C) in the 3′ untranslated region (3′UTR) of the TLR4 gene that may alter its expression and their association with metabolic disorders related to systemic inflammation. We cloned the 3′UTR into a luciferase reporter system and compared wild-type 3′UTR (WT) and +3725C variant (MUT) constructs luciferase activities. MUT construct reduced the reporter gene activity by 30% compared to WT (P = 0.0001). To evaluate the association between these polymorphisms with biochemical and clinical overweight related variables, we conducted a population cross-sectional study in 966 men of Argentine general population. Considering smoking as a confounding variable that causes systemic inflammation, we studied these possible effects in both, smokers and nonsmokers. The 11350G/C polymorphism was not detected in our sample whereas the CC genotype of +3725 polymorphism was associated with lean subjects (p = 0.011) and higher Adiponectin levels (p = 0.021). Subjects without any NCEP/ATP III MS component were associated with this genotype as well (p = 0.001). These results were strengthened in nonsmokers, in which CC genotype was associated with lean subjects (p = 0.003) and compared with G carriers showed significantly lower BMI (25.53 vs. 28.60 kg/m2; p = 0.023) and waist circumference (89.27 vs. 97.51 cm; p = 0.025). None of these associations were found in smokers. These results showed that +3725C variant has a functional effect down-regulating gene expression and it could be considered as a predictive factor against overweight, particularly in nonsmokers. Considering the role of TLR4 in inflammation, these findings would suggest that the presence of +3725C variant could predict a lower prevalence of chronic metabolic disorders.

Evaluation of cytochrome P450-derived eicosanoids in humans with stable atherosclerotic cardiovascular disease

OBJECTIVE

Preclinical and genetic epidemiologic studies suggest that modulating cytochrome P450 (CYP)-mediated arachidonic acid metabolism may have therapeutic utility in the management of coronary artery disease (CAD). However, predictors of inter-individual variation in CYP-derived eicosanoid metabolites in CAD patients have not been evaluated to date. Therefore, the primary objective was to identify clinical factors that influence CYP epoxygenase, soluble epoxide hydrolase (sEH), and CYP ω-hydroxylase metabolism in patients with established CAD.

METHODS

Plasma levels of epoxyeicosatrienoic acids (EETs), dihydroxyeicosatrienoic acids (DHETs), and 20-hydroxyeicosatetraenoic acid (20-HETE) were quantified by HPLC-MS/MS in a population of patients with stable, angiographically confirmed CAD (N=82) and healthy volunteers from the local community (N=36). Predictors of CYP epoxygenase, sEH, and CYP ω-hydroxylase metabolic function were evaluated by regression.

RESULTS

Obesity was significantly associated with low plasma EET levels and 14,15-EET:14,15-DHET ratios. Age, diabetes, and cigarette smoking also were significantly associated with CYP epoxygenase and sEH metabolic activity, while only renin-angiotensin system inhibitor use was associated with CYP ω-hydroxylase metabolic activity. Compared to healthy volunteers, both obese and non-obese CAD patients had significantly higher plasma EETs (P<0.01) and epoxide:diol ratios (P<0.01), whereas no difference in 20-HETE levels was observed (P=NS).

CONCLUSIONS

Collectively, these findings suggest that CYP-mediated eicosanoid metabolism is dysregulated in certain subsets of CAD patients, and demonstrate that biomarkers of CYP epoxygenase and sEH, but not CYP ω-hydroxylase, metabolism are altered in stable CAD patients relative to healthy individuals. Future studies are necessary to determine the therapeutic utility of modulating these pathways in patients with CAD.

Reno-protective mechanisms of epoxyeicosatrienoic acids in cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of mortality worldwide, and it is well known that end-stage renal disease (ESRD) is a profound consequence of the progression of CVD. Present treatments only slow CVD progression to ESRD, and it is imperative that new therapeutic strategies are developed to prevent the incidence of ESRD. Because epoxyeicosatrienoic acids (EETs) have been shown to elicit reno-protective effects in hypertensive animal models, the current review will focus on addressing the reno-protective mechanisms of EETs in CVD. The cytochrome P-450 epoxygenase catalyzes the oxidation of arachidonic acid to EETs. EETs have been identified as endothelium-derived hyperpolarizing factors (EDHFs) with vasodilatory, anti-inflammatory, antihypertensive, and antiplatelet aggregation properties. EETs also have profound effects on vascular migration and proliferation and promote angiogenesis. The progression of CVD has been linked to decreased EETs levels, leading to the concept that EETs should be therapeutically targeted to prevent end-organ damage associated with CVD. However, EETs are quickly degraded by the enzyme soluble epoxide hydrolase (sEH) to their less active diols, dihydroxyeicosatrienoic acids (DHETs). As such, one way to increase EETs level is to inhibit their degradation to DHETs by using sEH inhibitors. Inhibition of sEH has been shown to effectively reduce blood pressure and organ damage in experimental models of CVD. Another approach to target EETs is to develop EET analogs with improved solubility and resistance to auto-oxidation and metabolism by sEH. For example, stable ether EET analogs dilate afferent arterioles and lower blood pressure in hypertensive rodent animal models. EET agonists also improve insulin signaling and vascular function in animal models of metabolic syndrome.

The roles of CYP450 epoxygenases and metabolites, epoxyeicosatrienoic acids, in cardiovascular and malignant diseases

Cytochrome P450 (CYP) epoxygenases metabolize arachidonic acid to biologically active eicosanoids. The primary epoxidation products are four regioisomers of cis-epoxyeicosatrienoic acid (EET): 5,6-, 8,9-, 11,12-, and 14,15-EET. CYP2J2, CYP2C8, and CYP2C9 are the predominant epoxygenase isoforms involved in EET formation. CYP2J and CYP2C gene families in humans are abundantly expressed in the endothelium, myocardium, and kidney. The cardiovascular effects of CYP epoxygenases and EETs range from vasodilation, anti-hypertension, pro-angiogenesis, anti-atherosclerosis, and anti-inflammation to anti-injury caused by ischemia-reperfusion. Using transgenic animals for in vivo analyses of CYP epoxygenases revealed comprehensive and marked cardiovascular protective effects. In contrast, CYP epoxygenases and their metabolites, EETs, are upregulated in human tumors and promote tumor progression and metastasis. These biological effects result from the anti-apoptosis, pro-mitogenesis, and anti-migration roles of CYP epoxygenases and EETs at the cellular level. Importantly, soluble epoxide hydrolase (sEH) inhibitors are anti-hypertensive and anti-inflammatory and, therefore, protect the heart from damage, whereas the terfenadine-related, specific inhibitors of CYP2J2 exhibit strong anti-tumor activity in vitro and in vivo. Thus, CYP2J2 and arachidonic acid-derived metabolites likely play important roles in regulating cardiovascular functions and malignancy under physiological and/or pathological conditions. Moreover, although challenges remain to improving the drug-like properties of sEH inhibitors and identifying efficient ways to deliver sEH inhibitors, sEH will likely become an important therapeutic target for cardiovascular diseases. In addition, CYP2J2 may be a therapeutic target for treating human cancers and leukemia.

Impact of CYP2C8 and 2C9 polymorphisms on coronary artery disease and myocardial infarction in the LURIC cohort

Aims: As data on the cardiovascular risk associated with CYP2C8 and CYP2C9 polymorphisms is controversial, we performed a cross-sectional analysis of subjects enrolled in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. Materials & methods: CYP2C8 and CYP2C9 genetic polymorphisms were determined with real-time PCR in 2827 patients. Based on angiography, 1052 of these patients had coronary artery disease (CAD) and 615 did not; 1160 patients had signs or a history of myocardial infarction (MI) in addition to CAD. The association of genotypes with CAD and MI was determined by logistic regression analysis, adjusted for age, sex, dyslipidemia, hypertension, diabetes mellitus and smoking status. Results: Frequencies of CYP2C8 and 2C9 variants were neither significantly different between CAD and control patients, nor between MI and control patients. Men carrying the CYP2C9*3 allele had an increased risk of MI (odds ratio [OR]: 1.67; 95% CI: 1.06–2.63; p = 0.03) and women carrying the CYP2C9*3 allele had a decreased risk of CAD (OR: 0.65; 95%CI: 0.42–0.9; p = 0.05). Conclusion: Overall, LURIC data confirmed that there is no major cardiovascular risk associated with CYP2C8 and CYP2C9 variants in a cardiovascular risk population of patients having undergone coronary angiography.