Epoxide Hydrolase Enzyme Research Articles

Serum oxylipins indicate subcortical ischemic vascular disease in patients with clinical stroke

AbstractBackgroundSubcortical ischemic vascular disease (SIVD) is the most common vascular pathology found in patients with late onset dementia. The soluble epoxide hydrolase (sEH) enzyme inactivates anti‐inflammatory and vasoactive cytochrome p450 derived polyunsaturated fatty acid epoxides by converting them into cytotoxic dihydroxy (diol) oxylipin species. Previously, we found that the ratios of linoleic acid (LA) diols to epoxides were associated with more white matter hyperintensity (WMH) in patients with transient ischemic attack; however, it remains univestigated if these oxylipins can identify SIVD in patients with ischemic stroke of heterogenous cerebrovascular pathologies such as large vessel occlusion and lacunar infarcts.MethodThe study cohort comprises patients from the Ontario Neurodegenerative Disease Research Initiative, who has clinical stroke of either large or small vessel etiology (according to TOAST criteria). 4 LA oxylipins (12,13‐dihydroxyoctadecamonoenoic acid (12,13‐DiHOME), 12,13‐epoxyoctadecenoic acid (12,13‐EpOME), 9,10‐DiHOME, 9,10‐EpOME) were extracted from blood and quantified with a targeted ultrahigh pressure liquid chromatography mass spectrometry (UPLC‐MS/MS) WMH and perivascular spaces (PVS) were quantified from structural MRI scans using a personalized semi‐automatic processing pipeline (Lesion Explorer). The associations between oxylipins and small vessel disease markers were examined using linear regression models.ResultIn 80 stroke patients (n=50 large vessel disease and n=30 lacunar infarcts), the ratio of 12,13‐DiHOME to its epoxide sEH substrate 12,13‐EpOME was higher among patients with small vessel etiology (F1,79 = 4.55, p = 0.036). In linear regression models controlling for age, sex, APOE, waist hip ratio, diabetes, and hyperlipidemia, the same ratio, and the ratio of 9,10‐DiHOME/9,10‐EpOME were positively associated with volume of deep (β = 0.338, p = 0.004; β = 0.288, p = 0.012, respectively) and periventricular (β = 0.316, p = 0.003; β = 0.400, p < 0.001, respectively) WMH. The same ratios were associated with higher volumes of perivascular spaces in the white matter (β = 0.293, p = 0.013; β = 0.276, p = 0.016, respectively) but not in the basal ganglia (β = 0.145, p = 0.212; β = 0.086, p = 0.450, respectively).ConclusionOxylipins derived from sEH activity may contribute to cerebral small vessel disease and to stroke of small vessel etiology.

Molecular mechanisms of pulmonary carcinogenesis by polycyclic aromatic hydrocarbons (PAHs): Implications for human lung cancer.

Lung cancer has the second highest incidence and highest mortality compared to all other cancers. Polycyclic aromatic hydrocarbon (PAH) molecules belong to a class of compounds that are present in tobacco smoke, diesel exhausts, smoked foods, as well as particulate matter (PM). PAH-derived reactive metabolites are significant contributors to lung cancer development. The formation of these reactive metabolites entails metabolism of the parent PAHs by cytochrome P4501A1/1B1 (CYP1A1/1B1) and epoxide hydrolase enzymes. These reactive metabolites then react with DNA to form DNA adducts, which contribute to key gene mutations, such as the tumor suppressor gene, p53 and are linked to pulmonary carcinogenesis. PAH exposure also leads to upregulation of CYP1A1 transcription by binding to the aryl hydrocarbon receptor (AHR) and eliciting transcription of the CYP1A1 promoter, which comprises specific xenobiotic-responsive element (XREs). While hepatic and pulmonary CYP1A1/1B1 metabolize PAHs to DNA-reactive metabolites, the hepatic CYP1A2, however, may protect against lung tumor development by suppressing both liver and lung CYP1A1 enzymes. Further analysis of these enzymes has shown that PAH-exposure also induces sustained transcription of CYP1A1, which is independent of the persistence of the parent PAH. CYP1A2 enzyme plays an important role in the sustained induction of hepatic CYP1A1. PAH exposure may further contribute to pulmonary carcinogenesis by producing epigenetic alterations. DNA methylation, histone modification, long interspersed nuclear element (LINE-1) activation, and non-coding RNA, specifically microRNA (miRNA) alterations may all be induced by PAH exposure. The relationship between PAH-induced enzymatic reactive metabolite formation and epigenetic alterations is a key area of research that warrants further exploration. Investigation into the potential interplay between these two mechanisms may lead to further understanding of the mechanisms of PAH carcinogenesis. These mechanisms will be crucial for the development of effective targeted therapies and early diagnostic tools.

Exploring Quantitative Structure-Activity Relationships (QSARs) for Urea-Based Dual FAAH and sEH Inhibitors

Several urea-based compounds have been reported as dual inhibitors of Fatty acid amide hydrolase (FAAH) and Soluble epoxide hydrolase (sEH) enzymes which have potential as anti-inflammatory and antinociceptive agents. QSAR studies were performed on the urea analogs to identify the molecular descriptors influencing the FAAH and sEH inhibitory activity using Small Dataset Modeler tool. Molecular descriptors (1D &2D) were computed using PaDEL-Descriptor software. A set of forty-eight compounds was used in the present study. Statistically significant models were derived for both the enzymes [pIC50 (sEH): R2 = 0.797, Q2 = 0.762 and Q2F1 =0.747; pIC50 (FAAH): R2 = 0.642, Q2 = 0.521 and Q2F1 =0.566]. The results of QSAR on the sEH enzyme revealed the contribution of topological charge indices, ionization potential, and the number of nitrogen atoms (naaN) for defining the potency. Polarizability showed a major influence on FAAH inhibition. The predictive ability of the QSAR models was established based on the dual inhibitory potential of some newly designed molecules.

Organic-inorganic epoxide hydrolase hybrid nanoflowers with enhanced catalytic activity: Hydrolysis of styrene oxide to 1-phenyl-1,2-ethanediol

Epoxide hydrolases are ubiquitous in nature and are utilized to catalyze the cofactor-independent hydrolysis of epoxides to their corresponding diols. These enzymes have tremendous potential and have been applied in the synthesis of bulk and fine chemical industry and utilized as chiral building blocks. Herein, we report a green, facile, and economical method for immobilization of epoxide hydrolase based on biomimetic mineralization. The organic-inorganic hybrid nanoflowers have received tremendous attention due to their higher catalytic activity and stability. The nanoflowers were synthesized, with the organic component being enzyme epoxide hydrolase and the inorganic component being Ca2+ ions. A unique hierarchical flower-like spherical structure with hundreds of spiked petals was observed. The synthesized nanoflowers were applied for styrene oxide hydrolysis, producing 1-phenyl-1,2-ethanediol. Further, the factors influencing the morphology, catalytic activity, and stability studies were performed to study the activity recovery of the synthesized organic-inorganic hybrid epoxide hydrolase nanoflowers. The findings will have interesting applications.

Antibody Protection against Long-Term Memory Loss Induced by Monomeric C-Reactive Protein in a Mouse Model of Dementia.

Monomeric C-reactive protein (mCRP), the activated isoform of CRP, induces tissue damage in a range of inflammatory pathologies. Its detection in infarcted human brain tissue and its experimentally proven ability to promote dementia with Alzheimer’s disease (AD) traits at 4 weeks after intrahippocampal injection in mice have suggested that it may contribute to the development of AD after cerebrovascular injury. Here, we showed that a single hippocampal administration of mCRP in mice induced memory loss, lasting at least 6 months, along with neurodegenerative changes detected by increased levels of hyperphosphorylated tau protein and a decrease of the neuroplasticity marker Egr1. Furthermore, co-treatment with the monoclonal antibody 8C10 specific for mCRP showed that long-term memory loss and tau pathology were entirely avoided by early blockade of mCRP. Notably, 8C10 mitigated Egr1 decrease in the mouse hippocampus. 8C10 also protected against mCRP-induced inflammatory pathways in a microglial cell line, as shown by the prevention of increased generation of nitric oxide. Additional in vivo and in vitro neuroprotective testing with the anti-inflammatory agent TPPU, an inhibitor of the soluble epoxide hydrolase enzyme, confirmed the predominant involvement of neuroinflammatory processes in the dementia induced by mCRP. Therefore, locally deposited mCRP in the infarcted brain may be a novel biomarker for AD prognosis, and its antibody blockade opens up therapeutic opportunities for reducing post-stroke AD risk.

Alteration in antioxidant status in slow and fast alleles of EPHX1 gene polymorphisms among wood workers.

Occupational wood dust exposure may be associated with various health effects, especially in wood industry. These effects may be due to inducing oxidative stress which is related to inflammations. Biochemical assessment of antioxidant enzyme activities illustrated role of oxidative stress (OS) on its depletion. Super oxide dismutase, glutathione peroxidase (GPx) and catalase (CAT) were analyzed in 50 exposed workers and 50 control subjects. Also, macrophage inflammatory protein-2 was assessed among these workers as it was produced upon dust exposure. Microsomal epoxide hydrolase (EPHX1) enzyme shared in the protective mechanism against wood dust oxidative stress. It plays a dual role in the metabolism of environmental pollutants, detoxification, and bioactivation. Gene polymorphisms of EPHX1 may be associated with variations in enzyme activity. Polymorphisms in exons 3 and 4 have resulted in either decreased (slow conjugating allele) or increased (fast conjugating allele) activity in vitro. We aimed to evaluate the associations between EPHX1 polymorphisms and change in antioxidant status (SOD, CAT, and GPx) among wood dust exposed workers. EPHX1 genotyping in exon 3 and exon 4 polymorphisms was carried out by PCR-RFLP. Our result shows a significant reduction in enzymatic antioxidants (SOD, CAT, and GPx) levels with significant rise in MIP-2 levels in worker group. Also, there are significant variations in SOD, CAT, and GPx levels as well as in MIP-2 in different genotypes of EPHX polymorphisms in exon 3 or 4 (specially in Hist-Hist genotypes in both exons). We can conclude an alteration in antioxidant status in both slow and fast allele of EPHX gene polymorphisms with release of MIP-2 protein in wood workers.

Design, synthesis and anti-inflammatory/analgesic evaluation of novel di-substituted urea derivatives bearing diaryl-1,2,4-triazole with dual COX-2/sEH inhibitory activities

Herein, two novel series of diaryl-1,2,4-triazole hybrid to amide conjugates (5a-e) or urea conjugates (10a-f) have been synthesized followed by in vitro evaluation against cyclooxygenase-2/soluble epoxide hydrolase (COX-2/sEH) enzymes using ELISA enzyme assays. In vivo analgesic and anti-inflammatory activities for the new compounds have been carried out using the reported animal protocols. The preliminary results revealed that compounds 10e and 10c were the most active compounds against both COX-2/sEH enzymes (COX-2 IC50 = 1.98 µM and 2.13 µM; sEH = 1.09 and 1.23 nM, respectively). Moreover, the in vivo screening assays confirmed their superiority compared to the other derivatives by exhibiting higher anti-inflammatory and analgesic activity (91.27 and 89.32% edema inhibition; 55.97–50.00% writhing inhibition, respectively) than celecoxib (88.30% edema inhibition; 13.43% writhing inhibition). Collectively, compounds 10e and 10c can be considered as promising dual COX-2/sEH inhibitors with expected less cardiovascular adverse effects affording good anti-inflammatory and analgesic leads for further optimization.

Association of microsomal epoxide hydrolase gene (fast genotype) with lung functions impairment in wood workers.

Exposure to wood dust may lead to impairment of the lung functions. Microsomal epoxide hydrolase enzyme (EPHX1) was shown to take part in protection against oxidative stress. An alteration in enzyme activity might be associated with its gene polymorphisms. In vitro polymorphisms in exons 3 (His113Tyr) and 4 (Arg139His) lead to reduced activity (slow allele) and increased activity (fast allele). Macrophage inflammatory protein 2 (MIP-2) is produced in rat lung epithelial cells after exposure to fine particles. We aimed to investigate the associations between mEPHX1 polymorphisms (in exon 3 and 4) and lung function in furniture workers and assessment of MIP-2 effect. Our study was performed on 70 wood dust exposed male workers and 70 matched normal controls subjects. Ventilatory function tests were measured by spirometer, MIP-2 was performed by ELISA methods and EPHX gene was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods for each participant. Significant reduction in forced vital capacity (FVC%) and forced expiratory volume in the first second (FEV1) levels in Tyr-Tyr and Tyr-Hist genotypes of EPHX (exon 3) was observed. Reduced peak expiratory flow (PEF) levels and significant rise in MIP-2 levels were detected in Tyr-Tyr genotype. While high significant reduction in FVC% and FEV1 levels were shown in different genotypes in exon 4. Significant rise was observed in MIP-2 levels in Hist-Hist genotype of exon 4. An increase in duration of exposure showed positive correlation with fall in ventilatory functions. It was concluded that in Hist139Arg of EPHX gene, fast genotype (Arg-Arg) was associated with impaired ventilatory functions.

Development of multitarget inhibitors for the treatment of pain: Design, synthesis, biological evaluation and molecular modeling studies

Multitarget-directed ligands are a promising class of drugs for discovering innovative new therapies for difficult to treat diseases. In this study, we designed dual inhibitors targeting the human fatty acid amide hydrolase (FAAH) enzyme and human soluble epoxide hydrolase (sEH) enzyme. Targeting both of these enzymes concurrently with single target inhibitors synergistically reduces inflammatory and neuropathic pain; thus, dual FAAH/sEH inhibitors are likely to be powerful analgesics. Here, we identified the piperidinyl-sulfonamide moiety as a common pharmacophore and optimized several inhibitors to have excellent inhibition profiles on both targeted enzymes simultaneously. In addition, several inhibitors show good predicted pharmacokinetic properties. These results suggest that this series of inhibitors has the potential to be further developed as new lead candidates and therapeutics in pain management.

Suppression of inflammation and fibrosis using soluble epoxide hydrolase inhibitors enhances cardiac stem cell-based therapy.

Stem cell replacement offers a great potential for cardiac regenerative therapy. However, one of the critical barriers to stem cell therapy is a significant loss of transplanted stem cells from ischemia and inflammation in the host environment. Here, we tested the hypothesis that inhibition of the soluble epoxide hydrolase (sEH) enzyme using sEH inhibitors (sEHIs) to decrease inflammation and fibrosis in the host myocardium may increase the survival of the transplanted human induced pluripotent stem cell derived‐cardiomyocytes (hiPSC‐CMs) in a murine postmyocardial infarction model. A specific sEHI (1‐trifluoromethoxyphenyl‐3‐(1‐propionylpiperidine‐4‐yl)urea [TPPU]) and CRISPR/Cas9 gene editing were used to test the hypothesis. TPPU results in a significant increase in the retention of transplanted cells compared with cell treatment alone. The increase in the retention of hiPSC‐CMs translates into an improvement in the fractional shortening and a decrease in adverse remodeling. Mechanistically, we demonstrate a significant decrease in oxidative stress and apoptosis not only in transplanted hiPSC‐CMs but also in the host environment. CRISPR/Cas9‐mediated gene silencing of the sEH enzyme reduces cleaved caspase‐3 in hiPSC‐CMs challenged with angiotensin II, suggesting that knockdown of the sEH enzyme protects the hiPSC‐CMs from undergoing apoptosis. Our findings demonstrate that suppression of inflammation and fibrosis using an sEHI represents a promising adjuvant to cardiac stem cell‐based therapy. Very little is known regarding the role of this class of compounds in stem cell‐based therapy. There is consequently an enormous opportunity to uncover a potentially powerful class of compounds, which may be used effectively in the clinical setting.

Peripheral soluble epoxide hydrolase inhibition reduces hypernociception and inflammation in albumin-induced arthritis in temporomandibular joint of rats

Rheumatoid arthritis (RA) is characterized by chronic inflammation of the synovial tissue, joint dysfunction, and damage. Epoxyeicosatrienoic acids (EETs) are endogenous anti-inflammatory compounds, which are quickly converted by the soluble epoxide hydrolase (sEH) enzyme into a less active form with decreased biological effects. The inhibition of the sEH enzyme has been used as a strategy to lower nociception and inflammation. The goal of this study was to investigate whether the peripheral treatment with the sEH enzyme inhibitor 1- trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) could prevent the hypernociception and inflammation in the albumin-induced arthritis model in rats’ temporomandibular joint (TMJ). After the induction of experimental arthritis, animals were assessed for nociceptive behavior test, leukocyte infiltration counts and histologic analysis, ELISA to quantify several cytokines and Western blotting. The peripheral pretreatment with TPPU inhibited the arthritis-induced TMJ hypernociception and leukocyte migration. Moreover, the local concentrations of proinflammatory cytokines were diminished by TPPU, while the anti-inflammatory cytokine interleukin-10 was up-regulated in the TMJ tissue. Finally, TPPU significantly decreased protein expression of iNOS, while did not alter the expression of MRC1. This study provides evidence that the peripheral administration of TPPU reduces hypernociception and inflammation in TMJ experimental arthritis.

Novel amide derivatives of 3-phenylglutaric acid as potent soluble epoxide hydrolase inhibitors.

Soluble epoxide hydrolase (sEH) enzyme plays an important role in the metabolism of endogenous chemical mediators, epoxyeicosatrienoic acids, which are involved in the regulation of blood pressure and inflammation. According to the pharmacophoric model suggested for sEH inhibitors, some new amide-based derivatives of 3-phenylglutaric acid were designed, synthesized and biologically evaluated. Docking study illustrated that the amide group as a primary pharmacophore had a suitable distance from the three amino acids of Tyr383, Tyr466 and Asp335 for effective hydrogen binding. Most of the compounds showed moderate to high sEH inhibitory activities in in vitro test in comparison with 12-(3-Adamantan-1-yl-ureido)-dodecanoic acid, as a potent urea-based sEH inhibitor. Compound 6o with phenethyl in R position exhibited the highest activity with IC50 value of 0.5nM. In this study, some new amide-based derivatives of 3-phenylglutaric acid were designed, synthesized and biologically evaluated. Most of the synthesized compounds provided nanomolar range inhibition against sEH enzyme. The best observed IC50 value was 0.5nM. Incorporating a carboxylic moiety into these structures by forming carboxylate salts would increase the solubility and improving physicochemical properties.

Soluble epoxide hydrolase promotes astrocyte survival in retinopathy of prematurity.

Polyunsaturated fatty acids such as docosahexaenoic acid (DHA) positively affect the outcome of retinopathy of prematurity (ROP). Given that DHA metabolism by cytochrome P450 and soluble epoxide hydrolase (sEH) enzymes affects retinal angiogenesis and vascular stability, we investigated the role of sEH in a mouse model of ROP. In WT mice, hyperoxia elicited tyrosine nitration and inhibition of sEH and decreased generation of the DHA-derived diol 19,20-dihydroxydocosapentaenoic acid (19,20-DHDP). Correspondingly, in a murine model of ROP, sEH-/- mice developed a larger central avascular zone and peripheral pathological vascular tuft formation than did their WT littermates. Astrocytes were the cells most affected by sEH deletion, and hyperoxia increased astrocyte apoptosis. In rescue experiments, 19,20-DHDP prevented astrocyte loss by targeting the mitochondrial membrane to prevent the hyperoxia-induced dissociation of presenilin-1 and presenilin-1-associated protein to attenuate poly ADP-ribose polymerase activation and mitochondrial DNA damage. Therapeutic intravitreal administration of 19,20-DHDP not only suppressed astrocyte loss, but also reduced pathological vascular tuft formation in sEH-/- mice. Our data indicate that sEH activity is required for mitochondrial integrity and retinal astrocyte survival in ROP. Moreover, 19,20-DHDP may be more effective than DHA as a nutritional supplement for preventing retinopathy in preterm infants.

Role of Cytochrome p450 and Soluble Epoxide Hydrolase Enzymes and Their Associated Metabolites in the Pathogenesis of Diabetic Cardiomyopathy.

A plethora of studies have demonstrated that cardiomyopathy represents a serious source of morbidity and mortality in patients with diabetes. Yet, the underlying mechanisms of diabetic cardiomyopathy are still poorly understood. Of interest, cytochrome P450 2J (CYP2J) and soluble epoxide hydrolase (sEH) are known to control the maintenance of cardiovascular health through the regulation of cardioprotective epoxyeicosatrienoic acids (EETs) and its less active products, dihydroxyeicosatrienoic acids (DHETs). Therefore, we examined the role of the aforementioned pathway in the development of diabetic cardiomyopathy. Our diabetic model initiated cardiomyopathy as indexed by the increase in the expression of hypertrophic markers such as NPPA. Furthermore, diabetic cardiomyopathy was associated with a low level of cardiac EETs and an increase of the DHETs/EETs ratio both in vivo and in cardiac cells. The modulation in EETs and DHETs was attributed to the increase of sEH and the decrease of CYP2J. Interestingly, the reduction of sEH attenuates cardiotoxicity mediated by high glucose in cardiac cells. Mechanistically, the beneficial effect of sEH reduction might be due to the decrease of phosphorylated ERK1/2 and p38. Overall, the present work provides evidence that diabetes initiates cardiomyopathy through the increase in sEH, the reduction of CYP2J, and the decrease of cardioprotective EETs.

Discovery and Biosynthesis of Atrovimycin, an Antitubercular and Antifungal Cyclodepsipeptide Featuring Vicinal-dihydroxylated Cinnamic Acyl Chain.

Atrovimycin (1), a cyclodepsipeptide containing a unique vicinal-hydroxylated cinnamic acyl chain, was isolated and elucidated from Streptomyces atrovirens LQ13. The biosynthetic pathway of 1 was achieved, revealing cytochrome P450 (Avm43) and epoxide hydrolase (Avm29) enzymes constructing the vicinal-dihydroxy substitution, as well as a tailoring P450 (Avm28) enzyme catalyzing β-hydroxylation of the l-Phe moiety. Atrovimycin shows in vitro antifungal activity and antitubercular activity against Mycobacterium tuberculosis H37Rv both in vitro (with MIC of 2.5 μg/mL) and in vivo.

Abstract TP76: Combined MRI and Next Generation Sequencing of mRNA in Acute Ischemic Stroke Patients Reveal a Correlation Between Early Changes in Infarct and Angiogenesis

We previously showed that early changes in infarct volume (ECS) perform better as a predictor of early neurologic outcome in acute ischemic stroke (AIS) patients receiving thrombolysis when compared to percent recanalization (PER) and infarct volume at 24 hours (InVol), but the biologic explanation is unclear. We combined MRI and RNA Seq to compare the biologic associations. Methods: Pretreatment, 2-, and 24-hours post-thrombolysis MRIs were analyzed in 15 enrolled AIS patients treated with thrombolysis. ECS on the apparent diffusion coefficient sequence and PER on the perfusion scan were measured by comparing the pretreatment and 2-hour post thrombolysis MRI using automated co-registered MRI sequences within a region of interest defined by a > 4 second delay in time-to-peak on perfusion imaging using Matlab. InVol was measured on diffusion weighted images by a blinded reviewer. Blood samples were collected 2-hours and 24-hours post thrombolysis. RNA Seq was performed with HiSeq 25000 Illumina platform. After correcting for age, gender, and race, “leave one out testing” was used to select mRNA that correlated with the imaging variables (FDR corrected P-value < 0.05). Results: PER only correlated with 2 mRNA from 2-hour blood. InVol was associated with 20 mRNA from 24-hour blood. Both lacked significant disease and function associations. ECS correlated with 24 mRNA from 2-hour blood, with significant association with a decrease in IPA Ingenuity disease and functions annotations for both development of vasculature (P=0.005, Z-score -2.2) and angiogenesis (P=0.02, Z-score -2.2). Interestingly, IPA annotations for vascular development and angiogenesis include epoxyeicosatrienoic acid, a mediator of neurovascular coupling induced by cerebral ischemia, and degraded by soluble epoxide hydrolase enzyme (SEH). SEH inhibitor 12-(3-adamantan-1-yl-ureido) dodecanoic acid (AUDA) was a potential upstream regulator (P=5.03E-04), and AUDA has previously been shown to reduce infarct size in an animal model of ischemic stroke. Here we demonstrate the benefit of the combined MRI/blood biomarkers approach for elucidating biologic responses in AIS in identifying potential novel new therapeutics in humans, such as the epoxyeicosatrienoic pathway.

Association of Activity Altering Genotypes - Tyr113His and His139Arg in Microsomal Epoxide Hydrolase Enzyme with Esophageal Squamous Cell Carcinoma

The study aimed to explore the relationship of microsomal epoxide hydrolase (mEH) exon 3 (Tyr113His) and exon 4 (His139Arg) polymorphisms and predicted mEH activity with esophageal squamous cell carcinoma (ESCC) risk. 482 histologically confirmed cases and equal number of matched controls were analyzed by polymerase chain reaction-restriction length polymorphism (PCR-RFLP). Conditional logistic regression models were used to examine the association of polymorphisms with ESCC. We noted exon 3 slow genotype (OR = 6.57; CI 3.43–12.57) as well as predicted low mEH activity (OR = 3.99; CI 2.32–6.85) was associated with the ESCC risk. Elevated ESCC risk estimates were seen in smokers independent of genotypes but the association was stronger among smokers with exon 3 variant (OR = 6.67; 3.29–13.53) and low activity (OR = 7.52; CI 3.46–16.37) genotypes. Positive family history of cancer synergistically increased ESCC risk in the individuals who harbored exon 3 (OR = 13.59; CI 5.63–32.81) or altered mEH activity genotypes (OR = 13.35; CI 5.10–34.94). Significant interaction was seen between mEH exon 3 and exon 4 genotypes (P = 0.006) and between predicted mEH activity and positive family history of cancer (P = 0.018). These findings suggest association of ESCC risk with mEH polymorphisms which get modified by tobacco smoking and positive family history of cancer.

Design, Synthesis and Biological Activity of 4,6-disubstituted Pyridin-2(1H)-ones as Novel Inhibitors of Soluble Epoxide Hydrolase.

Soluble epoxide hydrolase enzyme is a promising therapeutic target for hypertension, vascular inflammation, pain and some other risk factors of cardiovascular diseases. The most potent sEH inhibitors reported in the literature are urea-based ones which often have poor bioavailability. In this study, in a quest for finding potent inhibitors of soluble epoxide hydrolase, some 4,6-disubstituted pyridin-2(1H)-one derivatives were designed and synthesized. The designed compounds fit properly in the active site pocket of this enzyme in docking studies and have appropriate distances for effective hydrogen binding to important amino acids Tyr383, Tyr466, and Asp335. The results of biological evaluation of these compounds against soluble epoxide hydrolase enzyme indicate most compounds have acceptable inhibitory activity and compound 9c is the most potent inhibitor with inhibitory activity of 86%.

Soluble epoxide hydrolase derived lipid mediators are elevated in bronchoalveolar lavage fluid from patients with sarcoidosis: a cross-sectional study

BackgroundSarcoidosis is a systemic inflammatory multi-organ disease almost always affecting the lungs. The etiology remains unknown, but the hallmark of sarcoidosis is formation of non-caseating epithelioid cells granulomas in involved organs. In Scandinavia, > 30% of sarcoidosis patients have Löfgren’s syndrome (LS), an acute disease onset mostly indicating a favorable prognosis. The impact of dysregulation of lipid mediators, which has been investigated in other inflammatory disorders, is still unknown.MethodsUsing three different liquid chromatography coupled to tandem mass spectrometry targeted platforms (LC-MS/MS), we quantified a broad suite of lipid mediators including eicosanoids, sphingolipids and endocannabinoids in bronchoalveolar lavage (BAL) fluid from pulmonary sarcoidosis patients (n = 41) and healthy controls (n = 16).ResultsA total of 47 lipid mediators were consistently detected in BAL fluid of patients and controls. After false discovery rate adjustment, two products of the soluble epoxide hydrolase (sEH) enzyme, 11,12-dihydroxyeicosa-5,8,14-trienoic acid (11,12-DiHETrE, p = 4.4E-5, q = 1.2E-3, median fold change = 6.0) and its regioisomer 14,15-dihydroxyeicosa-5,8,11-trienoic acid (14,15-DiHETrE, p = 3.6E-3, q = 3.2E-2, median fold change = 1.8) increased in patients with sarcoidosis. Additional shifts were observed in sphingolipid metabolism, with a significant increase in palmitic acid-derived sphingomyelin (SM16:0, p = 1.3E-3, q = 1.7E-2, median fold change = 1.3). No associations were found between these 3 lipid mediators and LS, whereas levels of SM 16:0 and 11,12-DiHETrE associated with radiological stage (p < 0.05), and levels of 14,15-DiHETrE were associated with the BAL fluid CD4/CD8 ratio.ConclusionsThese observed shifts in lipid mediators provide new insights into the pathobiology of sarcoidosis and in particular highlight the sEH pathway to be dysregulated in disease.

Soluble Epoxide Hydrolase-Derived Linoleic Acid Oxylipins in Serum Are Associated with Periventricular White Matter Hyperintensities and Vascular Cognitive Impairment.

White matter hyperintensities (WMH) are presumed to indicate subcortical ischemic vascular disease but their underlying pathobiology remains incompletely understood. The soluble epoxide hydrolase (sEH) enzyme converts anti-inflammatory and vasoactive cytochrome p450-derived polyunsaturated fatty acid epoxides into their less active corresponding diol species. Under the hypothesis that the activity of sEH might be associated with subcortical ischemic vascular disease and vascular cognitive impairment, this study aimed to compare the relative abundance of sEH substrates and products in peripheral blood between patients with extensive WMH (discovered due to transient ischemic attack; n = 29) and healthy elderly with minimal WMH (n = 25). The concentration of 12,13-DiHOME (a sEH-derived linoleic acid metabolite), and the ratio of 12,13-DiHOME to its sEH substrate, 12,13-EpOME, were elevated in the extensive WMH group (F1,53 = 5.9, p = 0.019), as was the 9,10-DiHOME/9,10-EpOME ratio (F1,53 = 5.4, p = 0.024). The 12,13-DiHOME/12,13-EpOME ratio was associated with poorer performance on a composite score derived from tests of psychomotor processing speed, attention, and executive function (β = - 0.473, p = 0.001, adjusted r2 = 0.213), but not with a composite verbal memory score. In a mediation model, periventricular WMH (but not deep WMH), explained 37% of the effect of the 12,13-DiHOME/12,13-EpOME ratio on the speed/attention/executive function composite score (indirect effect = - 0.50, 95% bootstrap confidence interval [- 0.99, - 0.17] Z-score units). Serum oxylipin changes consistent with higher sEH activity were markers of vascular cognitive impairment, and this association was partly explained by injury to the periventricular subcortical white matter.