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John R Falck - One of the best experts on this subject based on the ideXlab platform.

  • the cyp2c44 Epoxygenase regulates epithelial sodium channel activity and the blood pressure responses to increased dietary salt
    Journal of Biological Chemistry, 2014
    Co-Authors: Jorge H Capdevila, John R Falck, John D Imig, Raymond C Harris, Nataliya Pidkovka, Yan Gong, Wenhui Wang
    Abstract:

    Hypertension is a major risk factor for cerebral, cardiovascular, and renal disease, and its prevalence and devastating consequences raises a need for new strategies for its early diagnosis and treatment. We show here that lack of a Cyp2c44 Epoxygenase causes dietary salt-sensitive hypertension, a common form of the human disease. Cyp2c44(−/−) mice on normal salt diets are normotensive but become hypertensive when fed high salt. Hypertensive Cyp2c44(−/−) mice show a hyperactive kidney epithelial sodium channel (ENaC) and reductions in ERK1/2 and ENaC subunit phosphorylation. The demonstration that amiloride, an ENaC inhibitor, lowers the blood pressure of hypertensive Cyp2c44(−/−) mice identifies a role for the channel in the hypertensive phenotype of the animals. These studies: (a) identify an antihypertensive role for the kidney Cyp2c44 Epoxygenase and for its epoxyeicosatrienoic acid (EET) metabolites in the in vivo control of ENaC activity and the activation of mitogenic kinase pathways; (b) provide evidence for a Cyp2c44 Epoxygenase, EET-mediated mechanism of ENaC regulation involving an ERK1/2-catalyzed threonine phosphorylation of the channel γ subunit: and (c) characterize a common scientific platform that could explain the seemingly unrelated biological activities attributed to the Epoxygenase metabolites in cell proliferation, angiogenesis, channel activity, and blood pressure control. It is expected that these results will serve as a basis for the development of novel strategies for the early diagnosis and treatment of hypertension and of pathophysiologies associated with dysfunctional mitogenic signaling.

  • Pharmacological manipulation of arachidonic acid-Epoxygenase results in divergent effects on renal damage
    Frontiers Media S.A., 2014
    Co-Authors: Jing Eli, John R Falck, Vijaya L Manthati, Charles T. Stier, Praveen N. Chander, Mairead A. Carroll
    Abstract:

    Kidney damage is markedly accelerated by high-salt (HS) intake in stroke-prone spontaneously hypertensive rats (SHRSP). Epoxyeicosatrienoic acids (EETs) are Epoxygenase products of arachidonic acid which possess vasodepressor, natriuretic and anti-inflammatory activities. We examined whether up-regulation (clofibrate) or inhibition (MS-PPOH) of Epoxygenase would alter systolic blood pressure (SBP) and/or renal pathology in SHRSP on HS intake (1% NaCl drinking solution). Three weeks of treatment with clofibrate induced renal cortical protein expression of CYP2C23 and increased urinary excretion of EETs compared with vehicle-treated SHRSP. SBP and urinary protein excretion (UPE) were significantly lowered with clofibrate treatment. Kidneys from vehicle-treated SHRSP, which were on HS intake for 3 weeks, demonstrated focal lesions of vascular fibrinoid degeneration, which were markedly attenuated with clofibrate treatment. In contrast, 2 weeks of treatment with the selective Epoxygenase inhibitor, MS-PPOH, increased UPE without significantly altering neither urinary EET levels nor SBP. Kidneys from vehicle-treated SHRSP, which were on HS intake for 11 days, demonstrated occasional mild damage whereas kidneys from MS-PPOH-treated rats exhibited widespread malignant nephrosclerosis. These results suggest that pharmacological manipulation of Epoxygenase results in divergent effects on renal damage and that interventions to increase EET levels may provide therapeutic strategies for treating salt-sensitive hypertension and renal damage

  • Arachidonic Acid Inhibits Epithelial Na Channel Via Cytochrome P450 (CYP) Epoxygenase-dependent Metabolic Pathways
    2013
    Co-Authors: Yuan Wei, Daohong Lin, John R Falck, Rowena Kemp, Ganesh S. S. Yaddanapudi, Alberto Nasjletti, Wenhui Wang
    Abstract:

    abstract We used the patch-clamp technique to study the effect of arachidonic acid (AA) on epithelial Na channels (ENaC) in the rat cortical collecting duct (CCD). Application of 10 �M AA decreased the ENaC activity defined by NPo from 1.0 to 0.1. The dose–response curve of the AA effect on ENaC shows that 2 �M AA inhibited the ENaC activity by 50%. The effect of AA on ENaC is specific because neither 5,8,11,14-eicosatetraynoic acid (ETYA), a nonmetabolized analogue of AA, nor 11,14,17-eicosatrienoic acid mimicked the inhibitory effect of AA on ENaC. Moreover, inhibition of either cyclooxygenase (COX) with indomethacin or cytochrome P450 (CYP) �-hydroxylation with N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS) failed to abolish the effect of AA on ENaC. In contrast, the inhibitory effect of AA on ENaC was absent in the presence of N-methylsulfonyl-6-(propargyloxyphenyl)hexanamide (MS-PPOH), an agent that inhibits CYP-Epoxygenase activity. The notion that the inhibitory effect of AA is mediated by CYP-Epoxygenase–dependent metabolites is also supported by the observation that application of 200 nM 11,12-epoxyeicosatrienoic acid (EET) inhibited ENaC in the CCD. In contrast, addition of 5,6-, 8,9-, or 14,15-EET failed to decrease ENaC activity. Also, application of 11,12-EET can still reduce ENaC activity in the presence of MS-PPOH, suggesting that 11,12-EET is a mediator for the AA-induced inhibition of ENaC. Furthermore, gas chromatography mass spectrometry analysis detected the presence of 11,12-EET in the CCD and CYP2C23 is expressed in the principal cells of the CCD. We conclude that AA inhibits ENaC activity in the CCD and that the effect of AA is mediated by a CYP-Epoxygenase–dependent metabolite, 11,12-EET. key words

  • the protective effect of astrocyte derived 14 15 epoxyeicosatrienoic acid on hydrogen peroxide induced cell injury in astrocyte dopaminergic neuronal cell line co culture
    Neuroscience, 2012
    Co-Authors: Maia Terashvili, John R Falck, Pallabi Sarkar, Meg Van Nostrand, David R. Harder
    Abstract:

    Astrocytes perform several functions that are essential for normal neuronal activity. They play a critical role in neuronal survival during ischemia and other degenerative injuries and also modulate neuronal recovery by influencing neurite outgrowth. In this study, we investigated the neuroprotective effects of astrocyte-derived 14,15-epoxyeicosatrienoic acid (14,15-EET), metabolite of arachidonic acid by cytochrome P450 Epoxygenases (CYP), against oxidative stress induced by hydrogen peroxide (H(2)O(2)). We found that dopaminergic neuronal cells (N27 cell line) stimulated with two different doses of H(2)O(2) (0.1 and 1mM) for 1h showed decreased cell viability compared to the control group, while astrocytes showed less cell death after stimulation with the same doses of H(2)O(2) for 1h. Dopaminergic neuronal cells (N27 cell line) pretreated with different doses of 14,15-EET (0.1-30 μM, 30 min) before H(2)O(2) stimulation also showed increased cell viability. Furthermore, pre-treatment of the co-cultured cells with 12-(3-adamantan-1-yl-ureido)-dodecanoic acid, an inhibitor of the EET metabolizing enzyme, soluble epoxide hydrolase (sEH), before H(2)O(2) stimulation (1mM, for 1h) increased cell viability. It also increased the endogenous level of 14,15-EET in the media compared to control group. However, pretreatment with the CYP Epoxygenase inhibitor miconazole (1-20 μM, 1h) before H(2)O(2) (1mM, 1h) stimulation showed decreased cell viability. Our data suggest that 14,15-EET which is released from astrocytes, enhances cell viability against oxidant-induced injury. Further understanding of the mechanism of 14,15-EET-mediated protection in dopaminergic neurons is imperative, as it could lead to novel therapeutic approaches for treating CNS neuropathologies, such as Parkinson's disease.

  • inhibition of carcinoma cell motility by epoxyeicosatrienoic acid eet antagonists
    Cancer Science, 2010
    Co-Authors: Kasem Nithipatikom, John R Falck, Daniel M Brody, Alan T Tang, Vijaya L Manthati, Carol L Williams, William B. Campbell
    Abstract:

    Cytochrome P450 (CYP) Epoxygenases, CYP2C8, 2C9 and 2J2 mRNAs and proteins, were expressed in prostate carcinoma (PC-3, DU-145 and LNCaP) cells. 11,12-Epoxyeicosatrienoic acid (11,12-EET) was the major arachidonic acid metabolite in these cells. Blocking the EET synthesis by a selective CYP Epoxygenase inhibitor (MS-PPOH) inhibited tonic (basal) invasion and migration (motility) while exogenously added EETs induced cell motility in a concentration-dependent manner. An EGFR kinase inhibitor (AG494) or a PI3 kinase inhibitor (LY294002) inhibited cell migration and reduced 11,12-EET-induced cell migration. Importantly, synthetic EET antagonists (14,15-EEZE, 14,15-EEZE-PEG and 14,15-EEZE-mSI) inhibited EET-induced cell invasion and migration. 11,12-EET induced cell stretching and myosin-actin microfilament formation as well as increased phosphorylation of EGFR and Akt (Ser473) while 14,15-EEZE inhibited these effects. These results suggest that EETs induce and EET antagonists inhibit cell motility, possibly by putative EET receptor-mediated EGFR and PI3K/Akt pathways, and suggest EET antagonists as potential therapeutic agents for prostate cancer.

Jorge H Capdevila - One of the best experts on this subject based on the ideXlab platform.

  • the cyp2c44 Epoxygenase regulates epithelial sodium channel activity and the blood pressure responses to increased dietary salt
    Journal of Biological Chemistry, 2014
    Co-Authors: Jorge H Capdevila, John R Falck, John D Imig, Raymond C Harris, Nataliya Pidkovka, Yan Gong, Wenhui Wang
    Abstract:

    Hypertension is a major risk factor for cerebral, cardiovascular, and renal disease, and its prevalence and devastating consequences raises a need for new strategies for its early diagnosis and treatment. We show here that lack of a Cyp2c44 Epoxygenase causes dietary salt-sensitive hypertension, a common form of the human disease. Cyp2c44(−/−) mice on normal salt diets are normotensive but become hypertensive when fed high salt. Hypertensive Cyp2c44(−/−) mice show a hyperactive kidney epithelial sodium channel (ENaC) and reductions in ERK1/2 and ENaC subunit phosphorylation. The demonstration that amiloride, an ENaC inhibitor, lowers the blood pressure of hypertensive Cyp2c44(−/−) mice identifies a role for the channel in the hypertensive phenotype of the animals. These studies: (a) identify an antihypertensive role for the kidney Cyp2c44 Epoxygenase and for its epoxyeicosatrienoic acid (EET) metabolites in the in vivo control of ENaC activity and the activation of mitogenic kinase pathways; (b) provide evidence for a Cyp2c44 Epoxygenase, EET-mediated mechanism of ENaC regulation involving an ERK1/2-catalyzed threonine phosphorylation of the channel γ subunit: and (c) characterize a common scientific platform that could explain the seemingly unrelated biological activities attributed to the Epoxygenase metabolites in cell proliferation, angiogenesis, channel activity, and blood pressure control. It is expected that these results will serve as a basis for the development of novel strategies for the early diagnosis and treatment of hypertension and of pathophysiologies associated with dysfunctional mitogenic signaling.

  • epoxyeicosatrienoic acids eets regulate epithelial sodium channel activity by extracellular signal regulated kinase 1 2 erk1 2 mediated phosphorylation
    Journal of Biological Chemistry, 2013
    Co-Authors: Nataliya Pidkovka, Wenhui Wang, Raymond C Harris, Yan Gong, Jorge H Capdevila
    Abstract:

    The epithelial sodium channel (ENaC) participates in the regulation of plasma sodium and volume, and gain of function mutations in the human channel cause salt-sensitive hypertension. Roles for the arachidonic acid Epoxygenase metabolites, the epoxyeicosatrienoic acids (EETs), in ENaC activity have been identified; however, their mechanisms of action remain unknown. In polarized M1 cells, 14,15-EET inhibited amiloride-sensitive apical to basolateral sodium transport as effectively as epidermal growth factor (EGF). The EET effects were associated with increased threonine phosphorylation of the ENaC β and γ subunits and abolished by inhibitors of (a) mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/extracellular signal regulated kinases 1 and 2 (MEK/ERK1/2) and (b) EGF receptor signaling. CYP2C44 Epoxygenase knockdown blunted the sodium transport effects of EGF, and its 14,15-EET metabolite rescued the knockdown phenotype. The relevance of these findings is indicated by (a) the hypertension that results in mice administered cetuximab, an inhibitor of EGF receptor binding, and (b) immunological data showing an association between the pressure effects of cetuximab and reductions in ENaCγ phosphorylation. These studies (a) identify an ERK1/2-dependent mechanism for ENaC inhibition by 14,15-EET, (b) point to ENaC as a proximal target for EET-activated ERK1/2 mitogenic kinases, (c) characterize a mechanistic commonality between EGF and Epoxygenase metabolites as ENaC inhibitors, and (d) suggest a CYP2C Epoxygenase-mediated pathway for the regulation of distal sodium transport.

  • peroxisomal proliferator activated receptor α dependent inhibition of endothelial cell proliferation and tumorigenesis
    Journal of Biological Chemistry, 2007
    Co-Authors: Ambra Pozzi, John R Falck, Shilin Yang, Maria Raquel Ibanez, Arnaldo Gatica, Jorge H Capdevila
    Abstract:

    Abstract The peroxisomal proliferator-activated nuclear receptor-α (PPARα), the target for most hypolipidemic drugs in current clinical use, regulates the transcription of genes involved in lipid metabolism and transport, and energy homeostasis. More recently, PPARα and its ligands have been implicated in inflammatory responses and the regulation of cell proliferation. PPARα also regulates the expression of Cyp4a fatty acid ω-hydroxylases and Cyp2c arachidonic acid Epoxygenase genes. To study the role of the PPARα receptor and of its Cyp2c Epoxygenase gene target in tumorigenesis, we treated mice injected with tumor cells with Wy-14,643, a PPARα-selective ligand. Compared with untreated controls, Wy-14643-treated animals showed marked reductions in tumor growth and vascularization, which were accompanied by decreases in the plasma levels of pro-angiogenic Epoxygenase metabolites (EETs), hepatic EET biosynthesis, and Cyp2c Epoxygenase expression. All these Wy-14643-induced responses were absent in PPARα-/- mice and are thus PPARα-mediated. Primary cultures of mouse lung endothelial cells treated with Wy-14643 showed reductions in cell proliferation and in the formation of capillary-like structures. These effects were absent in cells obtained from PPRAα-/- mice and reversed by the addition of EETs. These results identify important anti-angiogenic and anti-tumorigenic roles for PPARα, characterize the contribution of its Cyp2c Epoxygenases gene target to these responses, and suggest potential anti-cancer roles for this nuclear receptor and its ligands.

  • enhanced renal microvascular reactivity to angiotensin ii in hypertension is ameliorated by the sulfonimide analog of 11 12 epoxyeicosatrienoic acid
    Journal of Hypertension, 2001
    Co-Authors: John D Imig, John R Falck, Xueying Zhao, Shouzou Wei, Jorge H Capdevila
    Abstract:

    OBJECTIVES Epoxygenase metabolites produced by the kidney affect renal blood flow and tubular transport function and 11,12-epoxyeicosatrienoic acid (11,12-EET) has been putatively identified as an endothelium-derived hyperpolarizing factor. The current studies were performed to determine the influence of 11,12-EET on the regulation of afferent arteriolar diameter in angiotensin II-infused hypertensive rats. MATERIALS AND METHODS Male Sprague-Dawley rats received angiotensin II (60 ng/min) or vehicle via an osmotic minipump. Angiotensin II-infused hypertensive and vehicle-infused normotensive rats were studied for 2 weeks following implantation of the minipump. Renal microvascular responses to the sulfonimide analog of 11,12-EET (11,12-EET-SI) and angiotensin II were observed utilizing the in-vitro juxtamedullary nephron preparation. Renal cortical Epoxygenase enzyme protein levels were quantified by Western blot analysis. Renal microvessels were also isolated and Epoxygenase metabolite levels measured by negative ion chemical ionization (NICI)/gas chromatography-mass spectroscopy. RESULTS Systolic blood pressure averaged 118 +/- 2 mmHg prior to pump implantation and increased to 185 +/- 7 mmHg in rats infused with angiotensin II for 2 weeks. Afferent arteriolar diameters of 2-week normotensive animals averaged 22 +/- 1 microm. Diameters of the afferent arterioles were 17% smaller in hypertensive rats (P< 0.05); however, arterioles from both groups responded to 11,12-EET-SI (100 nmol) with similar 15-17% increases in diameter. As we previously demonstrated, the afferent arteriolar reactivity to angiotensin II was enhanced in angiotensin II-infused animals. Interestingly, elevation of 11,12-EET-SI levels to 100 nmol reversed the enhanced vascular reactivity to angiotensin II associated with angiotensin II hypertension. Renal microvascular EET levels were not different between groups and averaged 81 +/- 9 and 87 +/- 13 pg/mg per 30 min in normotensive and hypertensive animals, respectively. Renal cortical microsomal levels of the Epoxygenase CYP2C23 and CYP2C11 proteins were also similar in normotensive and angiotensin II hypertensive rats. CONCLUSIONS Taken together, these data support the concept that renal microvascular 11,12-EET activity and levels may not properly offset the enhanced angiotensin II renal vasoconstriction during angiotensin II hypertension.

  • the kidney cytochrome p 450 2c23 arachidonic acid Epoxygenase is upregulated during dietary salt loading
    Journal of Clinical Investigation, 1999
    Co-Authors: Vijaykumar R Holla, Keiko Makita, Peter G Zaphiropoulos, Jorge H Capdevila
    Abstract:

    Excess dietary salt intake induces the activity of the kidney arachidonate Epoxygenase and markedly increases the urinary excretion of its metabolites. The epoxyeicosatrienoic acids, products of the kidney P-450 arachidonate Epoxygenase, inhibit distal nephron Na(+) reabsorption. Nucleic acid hybridization studies demonstrated the expression of P-450s 2C23, 2C24, and 2C11 as the predominant kidney 2C isoforms and the lack of significant dietary salt-dependent transcriptional regulation of these proteins. Recombinant P-450s 2C11, 2C23, and 2C24 catalyze arachidonate metabolism to mixtures of epoxy- and monohydroxylated acids. Whereas the arachidonate 11,12-olefin was the preferred target for epoxidation by P-450 2C23 (57% of total products), P-450s 2C11 and 2C24 epoxidized the 11,12-olefins and 14,15-olefins with nearly equal efficiency. Stereochemical comparisons demonstrated that the regiochemical and enantiofacial selectivity of P-450 2C23 matched that of the kidney microsomal Epoxygenase and that excess dietary salt does not alter the regiochemical or stereochemical selectivity of the kidney arachidonate Epoxygenase. Inhibition and immunoelectrophoresis experiments using antibodies raised against recombinant P-450s 2C11 and 2C23 demonstrated that P-450 2C23 is the major 2C arachidonic acid Epoxygenase in the rat kidney and the renal P-450 isoform regulated by excess dietary salt intake.

Darryl C. Zeldin - One of the best experts on this subject based on the ideXlab platform.

  • vascular endothelial overexpression of human cyp2j2 tie2 cyp2j2 tr modulates cardiac oxylipin profiles and enhances coronary reactive hyperemia in mice
    PLOS ONE, 2017
    Co-Authors: Ahmad Hanif, Darryl C. Zeldin, Matthew L Edin, Christophe Morisseau, Mohammed A Nayeem
    Abstract:

    Arachidonic acid is metabolized to epoxyeicosatrienoic acids (EETs) by cytochrome (CYP) P450 Epoxygenases, and to ω-terminal hydroxyeicosatetraenoic acids (HETEs) by ω-hydroxylases. EETs and HETEs often have opposite biologic effects; EETs are vasodilatory and protect against ischemia/reperfusion injury, while ω-terminal HETEs are vasoconstrictive and cause vascular dysfunction. Other oxylipins, such as epoxyoctadecaenoic acids (EpOMEs), hydroxyoctadecadienoic acids (HODEs), and prostanoids also have varied vascular effects. Post-ischemic vasodilation in the heart, known as coronary reactive hyperemia (CRH), protects against potential damage to the heart muscle caused by ischemia. The relationship among CRH response to ischemia, in mice with altered levels of CYP2J Epoxygenases has not yet been investigated. Therefore, we evaluated the effect of endothelial overexpression of the human cytochrome P450 Epoxygenase CYP2J2 in mice (Tie2-CYP2J2 Tr) on oxylipin profiles and CRH. Additionally, we evaluated the effect of pharmacologic inhibition of CYP-Epoxygenases and inhibition of ω-hydroxylases on CRH. We hypothesized that CRH would be enhanced in isolated mouse hearts with vascular endothelial overexpression of human CYP2J2 through modulation of oxylipin profiles. Similarly, we expected that inhibition of CYP-Epoxygenases would reduce CRH, whereas inhibition of ω-hydroxylases would enhance CRH. Compared to WT mice, Tie2-CYP2J2 Tr mice had enhanced CRH, including repayment volume, repayment duration, and repayment/debt ratio (P < 0.05). Similarly, inhibition of ω-hydroxylases increased repayment volume and repayment duration, in Tie2-CYP2J2 Tr compared to WT mice (P < 0.05). Endothelial overexpression of CYP2J2 significantly changed oxylipin profiles, including increased EETs (P < 0.05), increased EpOMEs (P < 0.05), and decreased 8-iso-PGF2α (P < 0.05). Inhibition of CYP Epoxygenases with MS-PPOH attenuated CRH (P < 0.05). Ischemia caused a decrease in mid-chain HETEs (5-, 11-, 12-, 15-HETEs P < 0.05) and HODEs (P < 0.05). These data demonstrate that vascular endothelial overexpression of CYP2J2, through changing the oxylipin profiles, enhances CRH. Inhibition of CYP Epoxygenases decreases CRH, whereas inhibition of ω-hydroxylases enhances CRH.

  • Inhibition of Vascular Smooth Muscle Cell Migration by
    2016
    Co-Authors: Cytochrome P, Darryl C. Zeldin, Alyce J Bradbury, Michael S Conte, Epoxygenase-derived Eicosanoids, Jianxin Sun, Xinxin Sui, James K Liao
    Abstract:

    Abstract—Vascular smooth muscle cell (SMC) migration and proliferation contribute to neointimal hyperplasia and restenosis after vascular injury. The epoxyeicosatrienoic acids (EETs), which are products of cytochrome P450 (CYP) Epoxygenases, possess vasodilatory, antiinflammatory, and fibrinolytic properties. To determine whether these compounds also possess antimigratory and antiproliferative properties, we stimulated rat aortic SMCs with either 20% serum or platelet-derived growth factor (PDGF-BB, 20 ng/mL). In a concentration-dependent manner, treatment with EETs, particularly 11,12-EET, inhibited SMC migration through a modified transwell filter by 53 % to 60%. EETs, however, have no inhibitory effects on PDGF-stimulated SMC proliferation. Adenoviral-mediated overexpression of the CYP isoform, CYP2J2, in SMCs also inhibited serum- and PDGF-induced SMC migration by 32 % and 26%, respectively; both effects of which were reversed by the CYP inhibitors SKF525A or clotrimazole, but not by the KCa channel blocker, charybdotoxin, or the cyclooxygenase inhibitor, diclofenac. The effect of EETs correlated with increases in intracellular cAMP levels. Indeed, forskolin and 8-bromo-cAMP exert similar inhibitory effects on SMC migration as 11,12-EET and the effects of 11,12-EET were blocked by cAMP and protein kinase A (PKA) inhibitors. These findings indicate that EETs possess antimigratory effects on SMCs through the cAMP-PKA pathway and suggest that CYP Epoxygenase-derived eicosanoids may play important roles in vascular disease and remodeling. (Circ Res. 2002;90:1020-1027.

  • Increased CYP2J3 Expression Reduces Insulin Resistance in Fructose-Treated Rats and db/db Mice
    2016
    Co-Authors: Matthew L Edin, Darryl C. Zeldin, Dao Wen Wang
    Abstract:

    OBJECTIVE—Accumulating evidence suggests that cyto-chrome P450 (CYP) Epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs), which play crucial and diverse roles in cardiovascular homeostasis. The anti-inflamma-tory, antihypertensive, and pro-proliferative effects of EETs suggest a possible beneficial role for EETs on insulin resistance and diabetes. RESEARCH DESIGN AND METHODS—This study investi-gated the effects of CYP2J3 Epoxygenase gene therapy on insulin resistance and blood pressure in diabetic db/db mice and in a model of fructose-induced hypertension and insulin resistance in rats. RESULTS—CYP2J3 gene delivery in vivo increased EET gener-ation, reduced blood pressure, and reversed insulin resistance as determined by plasma glucose levels, homeostasis model assess

  • effect of soluble epoxide hydrolase on the modulation of coronary reactive hyperemia role of oxylipins and pparγ
    PLOS ONE, 2016
    Co-Authors: Ahmad Hanif, Darryl C. Zeldin, Matthew L Edin, Christophe Morisseau, Mohammed A Nayeem
    Abstract:

    Coronary reactive hyperemia (CRH) is a physiological response to ischemic insult that prevents the potential harm associated with an interruption of blood supply. The relationship between the pharmacologic inhibition of soluble epoxide hydrolase (sEH) and CRH response to a brief ischemia is not known. sEH is involved in the main catabolic pathway of epoxyeicosatrienoic acids (EETs), which are converted into dihydroxyeicosatrienoic acids (DHETs). EETs protect against ischemia/reperfusion injury and have numerous beneficial physiological effects. We hypothesized that inhibition of sEH by t-AUCB enhances CRH in isolated mouse hearts through changing the oxylipin profiles, including an increase in EETs/DHETs ratio. Compared to controls, t-AUCB–treated mice had increased CRH, including repayment volume (RV), repayment duration, and repayment/debt ratio (p < 0.05). Treatment with t-AUCB significantly changed oxylipin profiles, including an increase in EET/DHET ratio, increase in EpOME/DiHOME ratio, increase in the levels of HODEs, decrease in the levels of mid-chain HETEs, and decrease in prostanoids (p < 0.05). Treatment with MS-PPOH (CYP Epoxygenase inhibitor) reduced CRH, including RV (p < 0.05). Involvement of PPARγ in the modulation of CRH was demonstrated using a PPARγ-antagonist (T0070907) and a PPARγ-agonist (rosiglitazone). T0070907 reduced CRH (p < 0.05), whereas rosiglitazone enhanced CRH (p < 0.05) in isolated mouse hearts compared to the non-treated. These data demonstrate that sEH inhibition enhances, whereas CYP Epoxygenases-inhibition attenuates CRH, PPARγ mediate CRH downstream of the CYP Epoxygenases-EET pathway, and the changes in oxylipin profiles associated with sEH-inhibition collectively contributed to the enhanced CRH.

  • Endogenous Epoxygenases Are Modulators of Monocyte/ Macrophage Activity
    2016
    Co-Authors: Jonas Bystrom, Darryl C. Zeldin, Matthew L Edin, Derek W Gilroy, Jessica Wray. A. ¤a, Mary C. Sugden, Mark J. Holness, Karen E. Swales¤b, Timothy D, David Bishop-bailey
    Abstract:

    Background: Arachidonic acid is metabolized through three major metabolic pathways, the cyclooxygenase, lipoxygenase and CYP450 enzyme systems. Unlike cyclooxygenase and lipoxygenases, the role of CYP450 Epoxygenases in monocyte/ macrophage-mediated responses is not known. Methodology/Principal Findings: When transfected in vitro, CYP2J2 is an efficient activator of anti-inflammatory pathways through the nuclear receptor peroxisome proliferator-activated receptor (PPAR) a. Human monocytes and macrophages contain PPARa and here we show they express the Epoxygenases CYP2J2 and CYP2C8. Inhibition of constitutive monocyte Epoxygenases using the Epoxygenase inhibitor SKF525A induces cyclooxygenase (COX)-2 expression and activity, and the release of TNFa, and can be reversed by either add back of the endogenous Epoxygenase products and PPARa ligand 11,12-epoxyeicosatrienoic acid (EET) or the addition of the selective synthetic PPARa ligand GW7647. In alternatively activated (IL-4-treated) monocytes, in contrast to classically activated cells, Epoxygenase inhibition decreased TNFa release. Epoxygenases can be pro-inflammatory via superoxide anion production. The suppression of TNFa by SKF525A in the presence of IL-4 was associated with a reduction in superoxide anion generation and reproduced by the superoxide dismutase MnCl2. Similar to these acute activation studies, in monocyte derived macrophages, Epoxygenase inhibition elevates M1 macrophage TNFa mRNA and further decreases M2 macrophage TNFa

Wenhui Wang - One of the best experts on this subject based on the ideXlab platform.

  • abstract p189 disruption of cyp2c44 increases sodium chloride cotransporter expression and activity in the distal convoluted tubule
    Hypertension, 2016
    Co-Authors: Lijun Wang, Daohong Lin, Michal L Schwartzman, Zhongxiuzi Gao, Varunkumar Pandey, Tong Wang, Nader G Abraham, Wenhui Wang
    Abstract:

    Cytochrome-P450 (CYP) Epoxygenase plays an important role in the regulation of renal sodium transport. Previous studies have demonstrated that global disruption of Cyp2c44, a major Epoxygenase in t...

  • the cyp2c44 Epoxygenase regulates epithelial sodium channel activity and the blood pressure responses to increased dietary salt
    Journal of Biological Chemistry, 2014
    Co-Authors: Jorge H Capdevila, John R Falck, John D Imig, Raymond C Harris, Nataliya Pidkovka, Yan Gong, Wenhui Wang
    Abstract:

    Hypertension is a major risk factor for cerebral, cardiovascular, and renal disease, and its prevalence and devastating consequences raises a need for new strategies for its early diagnosis and treatment. We show here that lack of a Cyp2c44 Epoxygenase causes dietary salt-sensitive hypertension, a common form of the human disease. Cyp2c44(−/−) mice on normal salt diets are normotensive but become hypertensive when fed high salt. Hypertensive Cyp2c44(−/−) mice show a hyperactive kidney epithelial sodium channel (ENaC) and reductions in ERK1/2 and ENaC subunit phosphorylation. The demonstration that amiloride, an ENaC inhibitor, lowers the blood pressure of hypertensive Cyp2c44(−/−) mice identifies a role for the channel in the hypertensive phenotype of the animals. These studies: (a) identify an antihypertensive role for the kidney Cyp2c44 Epoxygenase and for its epoxyeicosatrienoic acid (EET) metabolites in the in vivo control of ENaC activity and the activation of mitogenic kinase pathways; (b) provide evidence for a Cyp2c44 Epoxygenase, EET-mediated mechanism of ENaC regulation involving an ERK1/2-catalyzed threonine phosphorylation of the channel γ subunit: and (c) characterize a common scientific platform that could explain the seemingly unrelated biological activities attributed to the Epoxygenase metabolites in cell proliferation, angiogenesis, channel activity, and blood pressure control. It is expected that these results will serve as a basis for the development of novel strategies for the early diagnosis and treatment of hypertension and of pathophysiologies associated with dysfunctional mitogenic signaling.

  • abstract 040 upregulation of cyp Epoxygenase in the connecting tubule cnt cortical collecting duct ccd is essential for high potassium k intake induced antihypertensive effect
    Circulation Research, 2013
    Co-Authors: Chengbiao Zhang, Lijun Wang, Wenhui Wang
    Abstract:

    Cyp Epoxygenase is responsible for metabolizing arachidonic acid to epoxyeicosatrienoic acid (EET) in the kidney and vascular tissues. EET has been shown to cause vasodilation by stimulating Ca 2+ -activated K channels in vascular smooth muscles and to have natriuretic effect by inhibiting the epithelial Na channel (ENaC) in the kidney. In the present study we used real time PCR technique to examine the effect of high salt intake or high K intake on Cyp2c44 (a major type of Cyp Epoxygenase in the mouse kidney) in the proximal tubule (PxT), thick ascending limb (TAL), distal convoluted tubule (DCT) and the CNT/CCD. An increase in dietary Na content stimulates the expression of Cyp2c4 in TAL, DCT and CNT/CCD but not in PxT while an increase in dietary K intake augments the expression of Cyp2c44 only in DCT and CNT/CCD. Neither high salt intake nor high K intake has a significant effect on the blood pressure (BP) in wt mice. However, high K intake increased BP in CNT/CCD specific conditional knockout (KO) mice. In contrast, the high Na intake did not significantly increase the BP in those KO mice. This suggests that Cyp2c44 in the CNT/CCD plays a key role in preventing hypertension induced by increasing dietary K intake. Administration of amiloride (a ENaC inhibitor) restored the normal BP in KO mice fed high K diet, suggesting that down-regulation of Cyp2c44 may enhance the Na absorption in the CNT/CCD. This notion was also supported by metabolic cage study demonstrating that renal Na excretion was compromised in KO mice. We conclude that Cyp2c44 plays a key role in stimulating renal Na excretion during increasing dietary K intake and that Cyp-Epoxygenase is required for antihypertensive effect induced by high K intake.

  • Arachidonic Acid Inhibits Epithelial Na Channel Via Cytochrome P450 (CYP) Epoxygenase-dependent Metabolic Pathways
    2013
    Co-Authors: Yuan Wei, Daohong Lin, John R Falck, Rowena Kemp, Ganesh S. S. Yaddanapudi, Alberto Nasjletti, Wenhui Wang
    Abstract:

    abstract We used the patch-clamp technique to study the effect of arachidonic acid (AA) on epithelial Na channels (ENaC) in the rat cortical collecting duct (CCD). Application of 10 �M AA decreased the ENaC activity defined by NPo from 1.0 to 0.1. The dose–response curve of the AA effect on ENaC shows that 2 �M AA inhibited the ENaC activity by 50%. The effect of AA on ENaC is specific because neither 5,8,11,14-eicosatetraynoic acid (ETYA), a nonmetabolized analogue of AA, nor 11,14,17-eicosatrienoic acid mimicked the inhibitory effect of AA on ENaC. Moreover, inhibition of either cyclooxygenase (COX) with indomethacin or cytochrome P450 (CYP) �-hydroxylation with N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS) failed to abolish the effect of AA on ENaC. In contrast, the inhibitory effect of AA on ENaC was absent in the presence of N-methylsulfonyl-6-(propargyloxyphenyl)hexanamide (MS-PPOH), an agent that inhibits CYP-Epoxygenase activity. The notion that the inhibitory effect of AA is mediated by CYP-Epoxygenase–dependent metabolites is also supported by the observation that application of 200 nM 11,12-epoxyeicosatrienoic acid (EET) inhibited ENaC in the CCD. In contrast, addition of 5,6-, 8,9-, or 14,15-EET failed to decrease ENaC activity. Also, application of 11,12-EET can still reduce ENaC activity in the presence of MS-PPOH, suggesting that 11,12-EET is a mediator for the AA-induced inhibition of ENaC. Furthermore, gas chromatography mass spectrometry analysis detected the presence of 11,12-EET in the CCD and CYP2C23 is expressed in the principal cells of the CCD. We conclude that AA inhibits ENaC activity in the CCD and that the effect of AA is mediated by a CYP-Epoxygenase–dependent metabolite, 11,12-EET. key words

  • epoxyeicosatrienoic acids eets regulate epithelial sodium channel activity by extracellular signal regulated kinase 1 2 erk1 2 mediated phosphorylation
    Journal of Biological Chemistry, 2013
    Co-Authors: Nataliya Pidkovka, Wenhui Wang, Raymond C Harris, Yan Gong, Jorge H Capdevila
    Abstract:

    The epithelial sodium channel (ENaC) participates in the regulation of plasma sodium and volume, and gain of function mutations in the human channel cause salt-sensitive hypertension. Roles for the arachidonic acid Epoxygenase metabolites, the epoxyeicosatrienoic acids (EETs), in ENaC activity have been identified; however, their mechanisms of action remain unknown. In polarized M1 cells, 14,15-EET inhibited amiloride-sensitive apical to basolateral sodium transport as effectively as epidermal growth factor (EGF). The EET effects were associated with increased threonine phosphorylation of the ENaC β and γ subunits and abolished by inhibitors of (a) mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/extracellular signal regulated kinases 1 and 2 (MEK/ERK1/2) and (b) EGF receptor signaling. CYP2C44 Epoxygenase knockdown blunted the sodium transport effects of EGF, and its 14,15-EET metabolite rescued the knockdown phenotype. The relevance of these findings is indicated by (a) the hypertension that results in mice administered cetuximab, an inhibitor of EGF receptor binding, and (b) immunological data showing an association between the pressure effects of cetuximab and reductions in ENaCγ phosphorylation. These studies (a) identify an ERK1/2-dependent mechanism for ENaC inhibition by 14,15-EET, (b) point to ENaC as a proximal target for EET-activated ERK1/2 mitogenic kinases, (c) characterize a mechanistic commonality between EGF and Epoxygenase metabolites as ENaC inhibitors, and (d) suggest a CYP2C Epoxygenase-mediated pathway for the regulation of distal sodium transport.

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  • epoxide hydrolase 1 ephx1 hydrolyzes epoxyeicosanoids and impairs cardiac recovery after ischemia
    Journal of Biological Chemistry, 2018
    Co-Authors: Matthew L Edin, Behin Gholipour Hamedani, Artiom Gruzdev, Joan P Graves, Fred B Lih, Samuel J Arbes, Rohanit Singh, Anette Orjuela C Leon, Alyce J Bradbury, Laura M Degraff
    Abstract:

    Stimuli such as inflammation or hypoxia induce cytochrome P450 Epoxygenase-mediated production of arachidonic acid-derived epoxyeicosatrienoic acids (EETs). EETs have cardioprotective, vasodilatory, angiogenic, anti-inflammatory, and analgesic effects, which are diminished by EET hydrolysis yielding biologically less active dihydroxyeicosatrienoic acids (DHETs). Previous in vitro assays have suggested that epoxide hydrolase 2 (EPHX2) is responsible for nearly all EET hydrolysis. EPHX1, which exhibits slow EET hydrolysis in vitro, is thought to contribute only marginally to EET hydrolysis. Using Ephx1-/-, Ephx2-/-, and Ephx1-/-Ephx2-/- mice, we show here that EPHX1 significantly contributes to EET hydrolysis in vivo Disruption of Ephx1 and/or Ephx2 genes did not induce compensatory changes in expression of other Ephx genes or CYP2 family Epoxygenases. Plasma levels of 8,9-, 11,12-, and 14,15-DHET were reduced by 38, 44, and 67% in Ephx2-/- mice compared with wildtype (WT) mice, respectively; however, plasma from Ephx1-/-Ephx2-/- mice exhibited significantly greater reduction (100, 99, and 96%) of those respective DHETs. Kinetic assays and FRET experiments indicated that EPHX1 is a slow EET scavenger, but hydrolyzes EETs in a coupled reaction with cytochrome P450 to limit basal EET levels. Moreover, we also found that EPHX1 activities are biologically relevant, as Ephx1-/-Ephx2-/- hearts had significantly better postischemic functional recovery (71%) than both WT (31%) and Ephx2-/- (51%) hearts. These findings indicate that Ephx1-/-Ephx2-/- mice are a valuable model for assessing EET-mediated effects, uncover a new paradigm for EET metabolism, and suggest that dual EPHX1 and EPHX2 inhibition may represent a therapeutic approach to manage human pathologies such as myocardial infarction.

  • vascular endothelial overexpression of human cyp2j2 tie2 cyp2j2 tr modulates cardiac oxylipin profiles and enhances coronary reactive hyperemia in mice
    PLOS ONE, 2017
    Co-Authors: Ahmad Hanif, Darryl C. Zeldin, Matthew L Edin, Christophe Morisseau, Mohammed A Nayeem
    Abstract:

    Arachidonic acid is metabolized to epoxyeicosatrienoic acids (EETs) by cytochrome (CYP) P450 Epoxygenases, and to ω-terminal hydroxyeicosatetraenoic acids (HETEs) by ω-hydroxylases. EETs and HETEs often have opposite biologic effects; EETs are vasodilatory and protect against ischemia/reperfusion injury, while ω-terminal HETEs are vasoconstrictive and cause vascular dysfunction. Other oxylipins, such as epoxyoctadecaenoic acids (EpOMEs), hydroxyoctadecadienoic acids (HODEs), and prostanoids also have varied vascular effects. Post-ischemic vasodilation in the heart, known as coronary reactive hyperemia (CRH), protects against potential damage to the heart muscle caused by ischemia. The relationship among CRH response to ischemia, in mice with altered levels of CYP2J Epoxygenases has not yet been investigated. Therefore, we evaluated the effect of endothelial overexpression of the human cytochrome P450 Epoxygenase CYP2J2 in mice (Tie2-CYP2J2 Tr) on oxylipin profiles and CRH. Additionally, we evaluated the effect of pharmacologic inhibition of CYP-Epoxygenases and inhibition of ω-hydroxylases on CRH. We hypothesized that CRH would be enhanced in isolated mouse hearts with vascular endothelial overexpression of human CYP2J2 through modulation of oxylipin profiles. Similarly, we expected that inhibition of CYP-Epoxygenases would reduce CRH, whereas inhibition of ω-hydroxylases would enhance CRH. Compared to WT mice, Tie2-CYP2J2 Tr mice had enhanced CRH, including repayment volume, repayment duration, and repayment/debt ratio (P < 0.05). Similarly, inhibition of ω-hydroxylases increased repayment volume and repayment duration, in Tie2-CYP2J2 Tr compared to WT mice (P < 0.05). Endothelial overexpression of CYP2J2 significantly changed oxylipin profiles, including increased EETs (P < 0.05), increased EpOMEs (P < 0.05), and decreased 8-iso-PGF2α (P < 0.05). Inhibition of CYP Epoxygenases with MS-PPOH attenuated CRH (P < 0.05). Ischemia caused a decrease in mid-chain HETEs (5-, 11-, 12-, 15-HETEs P < 0.05) and HODEs (P < 0.05). These data demonstrate that vascular endothelial overexpression of CYP2J2, through changing the oxylipin profiles, enhances CRH. Inhibition of CYP Epoxygenases decreases CRH, whereas inhibition of ω-hydroxylases enhances CRH.

  • Increased CYP2J3 Expression Reduces Insulin Resistance in Fructose-Treated Rats and db/db Mice
    2016
    Co-Authors: Matthew L Edin, Darryl C. Zeldin, Dao Wen Wang
    Abstract:

    OBJECTIVE—Accumulating evidence suggests that cyto-chrome P450 (CYP) Epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs), which play crucial and diverse roles in cardiovascular homeostasis. The anti-inflamma-tory, antihypertensive, and pro-proliferative effects of EETs suggest a possible beneficial role for EETs on insulin resistance and diabetes. RESEARCH DESIGN AND METHODS—This study investi-gated the effects of CYP2J3 Epoxygenase gene therapy on insulin resistance and blood pressure in diabetic db/db mice and in a model of fructose-induced hypertension and insulin resistance in rats. RESULTS—CYP2J3 gene delivery in vivo increased EET gener-ation, reduced blood pressure, and reversed insulin resistance as determined by plasma glucose levels, homeostasis model assess

  • effect of soluble epoxide hydrolase on the modulation of coronary reactive hyperemia role of oxylipins and pparγ
    PLOS ONE, 2016
    Co-Authors: Ahmad Hanif, Darryl C. Zeldin, Matthew L Edin, Christophe Morisseau, Mohammed A Nayeem
    Abstract:

    Coronary reactive hyperemia (CRH) is a physiological response to ischemic insult that prevents the potential harm associated with an interruption of blood supply. The relationship between the pharmacologic inhibition of soluble epoxide hydrolase (sEH) and CRH response to a brief ischemia is not known. sEH is involved in the main catabolic pathway of epoxyeicosatrienoic acids (EETs), which are converted into dihydroxyeicosatrienoic acids (DHETs). EETs protect against ischemia/reperfusion injury and have numerous beneficial physiological effects. We hypothesized that inhibition of sEH by t-AUCB enhances CRH in isolated mouse hearts through changing the oxylipin profiles, including an increase in EETs/DHETs ratio. Compared to controls, t-AUCB–treated mice had increased CRH, including repayment volume (RV), repayment duration, and repayment/debt ratio (p < 0.05). Treatment with t-AUCB significantly changed oxylipin profiles, including an increase in EET/DHET ratio, increase in EpOME/DiHOME ratio, increase in the levels of HODEs, decrease in the levels of mid-chain HETEs, and decrease in prostanoids (p < 0.05). Treatment with MS-PPOH (CYP Epoxygenase inhibitor) reduced CRH, including RV (p < 0.05). Involvement of PPARγ in the modulation of CRH was demonstrated using a PPARγ-antagonist (T0070907) and a PPARγ-agonist (rosiglitazone). T0070907 reduced CRH (p < 0.05), whereas rosiglitazone enhanced CRH (p < 0.05) in isolated mouse hearts compared to the non-treated. These data demonstrate that sEH inhibition enhances, whereas CYP Epoxygenases-inhibition attenuates CRH, PPARγ mediate CRH downstream of the CYP Epoxygenases-EET pathway, and the changes in oxylipin profiles associated with sEH-inhibition collectively contributed to the enhanced CRH.

  • The Cytochrome P450 Epoxygenase Pathway Regulates the Hepatic Inflammatory Response in Fatty Liver Disease
    2016
    Co-Authors: Robert N Schuck, Matthew L Edin, Artiom Gruzdev, Fred B Lih, Laura M Degraff, Weibin Zha, Kimberly C. Vendrov, Tricia M. Miller, Kenneth B Tomer
    Abstract:

    Fatty liver disease is an emerging public health problem without effective therapies, and chronic hepatic inflammation is a key pathologic mediator in its progression. Cytochrome P450 (CYP) Epoxygenases metabolize arachidonic acid to biologically active epoxyeicosatrienoic acids (EETs), which have potent anti-inflammatory effects. Although promoting the effects of EETs elicits anti-inflammatory and protective effects in the cardiovascular system, the contribution of CYP-derived EETs to the regulation of fatty liver disease-associated inflammation and injury is unknown. Using the atherogenic diet model of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH), our studies demonstrated that induction of fatty liver disease significantly and preferentially suppresses hepatic CYP Epoxygenase expression and activity, and both hepatic and circulating levels of EETs in mice. Furthermore, mice with targeted disruption of Ephx2 (the gene encoding soluble epoxide hydrolase) exhibited restored hepatic and circulating EET levels and a significantly attenuate