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Abstract
The endothelium controls vascular tone not only by releasing NO and prostacyclin, but also by other pathways causing hyperpolarization of the underlying smooth muscle cells. This characteristic was at the origin of the term 'endothelium-derived hyperpolarizing factor' (EDHF). However, this acronym includes different mechanisms. Arachidonic acid metabolites derived from the cyclo-oxygenases, lipoxygenases and cytochrome P450 pathways, H(2)O(2), CO, H(2)S and various peptides can be released by endothelial cells. These factors activate different families of K(+) channels and hyperpolarization of the vascular smooth muscle cells contribute to the mechanisms leading to their relaxation. Additionally, another pathway associated with the hyperpolarization of both endothelial and vascular smooth muscle cells contributes also to endothelium-dependent relaxations (EDHF-mediated responses). These responses involve an increase in the intracellular Ca(2+) concentration of the endothelial cells, followed by the opening of SK(Ca) and IK(Ca) channels (small and intermediate conductance Ca(2+)-activated K(+) channels respectively). These channels have a distinct subcellular distribution: SK(Ca) are widely distributed over the plasma membrane, whereas IK(Ca) are preferentially expressed in the endothelial projections toward the smooth muscle cells. Following SK(Ca) activation, smooth muscle hyperpolarization is preferentially evoked by electrical coupling through myoendothelial gap junctions, whereas, following IK(Ca) activation, K(+) efflux can activate smooth muscle Kir2.1 and/or Na(+)/K(+)-ATPase. EDHF-mediated responses are altered by aging and various pathologies. Therapeutic interventions can restore these responses, suggesting that the improvement in the EDHF pathway contributes to their beneficial effect. A better characterization of EDHF-mediated responses should allow the determination of whether or not new drugable targets can be identified for the treatment of cardiovascular diseases.
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102
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Manhiani M, Quigley JE, Knight SF, Tasoobshirazi S, Moore T, Brands MW, Hammock BD, Imig JD. Soluble epoxide hydrolase gene deletion attenuates renal injury and inflammation with DOCA-salt hypertension. Am J Physiol Renal Physiol 2009; 297:F740-8. [PMID: 19553349 DOI: 10.1152/ajprenal.00098.2009] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Inhibition of soluble epoxide hydrolase (sEH) has been shown to be renal protective in rat models of salt-sensitive hypertension. Here, we hypothesize that targeted disruption of the sEH gene (Ephx2) prevents both renal inflammation and injury in deoxycorticosterone acetate plus high salt (DOCA-salt) hypertensive mice. Mean arterial blood pressure (MAP) increased significantly in the DOCA-salt groups, and MAP was lower in Ephx2-/- DOCA-salt (129 +/- 3 mmHg) compared with wild-type (WT) DOCA-salt (145 +/- 2 mmHg) mice. Following 21 days of treatment, WT DOCA-salt urinary MCP-1 excretion increased from control and was attenuated in the Ephx2-/- DOCA-salt group. Macrophage infiltration was reduced in Ephx2-/- DOCA-salt compared with WT DOCA-salt mice. Albuminuria increased in WT DOCA-salt (278 +/- 55 microg/day) compared with control (17 +/- 1 microg/day) and was blunted in the Ephx2-/- DOCA-salt mice (97 +/- 23 microg/day). Glomerular nephrin expression demonstrated an inverse relationship with albuminuria. Nephrin immunofluorescence was greater in the Ephx2-/- DOCA-salt group (3.4 +/- 0.3 RFU) compared with WT DOCA-salt group (1.1 +/- 0.07 RFU). Reduction in renal inflammation and injury was also seen in WT DOCA-salt mice treated with a sEH inhibitor {trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid; tAUCB}, demonstrating that the C-terminal hydrolase domain of the sEH enzyme is responsible for renal protection with DOCA-salt hypertension. These data demonstrate that Ephx2 gene deletion decreases blood pressure, attenuates renal inflammation, and ameliorates glomerular injury in DOCA-salt hypertension.
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Affiliation(s)
- Marlina Manhiani
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia, USA
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103
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Decker M, Arand M, Cronin A. Mammalian epoxide hydrolases in xenobiotic metabolism and signalling. Arch Toxicol 2009; 83:297-318. [PMID: 19340413 DOI: 10.1007/s00204-009-0416-0] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 02/16/2009] [Indexed: 12/14/2022]
Abstract
Epoxide hydrolases catalyse the hydrolysis of electrophilic--and therefore potentially genotoxic--epoxides to the corresponding less reactive vicinal diols, which explains the classification of epoxide hydrolases as typical detoxifying enzymes. The best example is mammalian microsomal epoxide hydrolase (mEH)-an enzyme prone to detoxification-due to a high expression level in the liver, a broad substrate selectivity, as well as inducibility by foreign compounds. The mEH is capable of inactivating a large number of structurally different, highly reactive epoxides and hence is an important part of the enzymatic defence of our organism against adverse effects of foreign compounds. Furthermore, evidence is accumulating that mammalian epoxide hydrolases play physiological roles other than detoxification, particularly through involvement in signalling processes. This certainly holds true for soluble epoxide hydrolase (sEH) whose main function seems to be the turnover of lipid derived epoxides, which are signalling lipids with diverse functions in regulatory processes, such as control of blood pressure, inflammatory processes, cell proliferation and nociception. In recent years, the sEH has attracted attention as a promising target for pharmacological inhibition to treat hypertension and possibly other diseases. Recently, new hitherto uncharacterised epoxide hydrolases could be identified in mammals by genome analysis. The expression pattern and substrate selectivity of these new epoxide hydrolases suggests their participation in signalling processes rather than a role in detoxification. Taken together, epoxide hydrolases (1) play a central role in the detoxification of genotoxic epoxides and (2) have an important function in the regulation of physiological processes by the control of signalling molecules with an epoxide structure.
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Affiliation(s)
- Martina Decker
- Institute of Pharmacology and Toxicology, University of Zürich, Winterthurer Str. 190, 8057 Zurich, Switzerland
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104
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Iliff JJ, Alkayed NJ. Soluble Epoxide Hydrolase Inhibition: Targeting Multiple Mechanisms of Ischemic Brain Injury with a Single Agent. FUTURE NEUROLOGY 2009; 4:179-199. [PMID: 19779591 DOI: 10.2217/14796708.4.2.179] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Soluble epoxide hydrolase (sEH) is a key enzyme in the metabolic conversion and degradation of P450 eicosanoids called epoxyeicosatrienoic acids (EETs). Genetic variations in the sEH gene, designated EPHX2, are associated with ischemic stroke risk. In experimental studies, sEH inhibition and gene deletion reduce infarct size after focal cerebral ischemia in mice. Although the precise mechanism of protection afforded by sEH inhibition remains under investigation, EETs exhibit a wide array of potentially beneficial actions in stroke, including vasodilation, neuroprotection, promotion of angiogenesis and suppression of platelet aggregation, oxidative stress and post-ischemic inflammation. Herein we argue that by capitalizing on this broad protective profile, sEH inhibition represents a prototype "combination therapy" targeting multiple mechanisms of stroke injury with a single agent.
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Affiliation(s)
- Jeffrey J Iliff
- Department of Anesthesiology and Peri-Operative Medicine, Oregon Health and Science University, Portland OR 97239
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105
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Liu JY, Tsai HJ, Hwang SH, Jones PD, Morisseau C, Hammock BD. Pharmacokinetic optimization of four soluble epoxide hydrolase inhibitors for use in a murine model of inflammation. Br J Pharmacol 2009; 156:284-96. [PMID: 19154430 DOI: 10.1111/j.1476-5381.2008.00009.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Early soluble epoxide hydrolase inhibitors (sEHIs) such as 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) are effective anti-hypertensive and anti-inflammatory agents in various animal models. However, their poor metabolic stability and limited water solubility make them difficult to use pharmacologically. Here we present the evaluation of four sEHIs for improved pharmacokinetic properties and the anti-inflammatory effects of one sEHI. EXPERIMENTAL APPROACH The pharmacokinetic profiles of inhibitors were determined following p.o. (oral) administration and serial bleeding in mice. Subsequently the pharmacokinetics of trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB), the most promising inhibitor, was further studied following s.c. (subcutaneous), i.v. (intravenous) injections and administration in drinking water. Finally, the anti-inflammatory effect of t-AUCB was evaluated by using a lipopolysaccharide (LPS)-treated murine model. KEY RESULTS Better pharmacokinetic parameters (higher C(max), longer t(1/2) and greater AUC) were obtained from the tested inhibitors, compared with AUDA. Oral bioavailability of t-AUCB (0.1 mg.kg(-1)) was 68 +/- 22% (n = 4), and giving t-AUCB in drinking water is recommended as a feasible, effective and easy route of administration for chronic studies. Finally, t-AUCB (p.o.) reversed the decrease in plasma ratio of lipid epoxides to corresponding diols (a biomarker of soluble epoxide hydrolase inhibition) in lipopolysaccharide-treated mice. The in vivo potency of 1 mg.kg(-1) of t-AUCB (p.o.) was better in this inflammatory model than that of 10 mg.kg(-1) of AUDA-butyl ester (p.o) at 6 h after treatment. CONCLUSIONS AND IMPLICATIONS t-AUCB is a potent sEHI with improved pharmacokinetic properties. This compound will be a useful tool for pharmacological research and a promising starting point for drug development.
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Affiliation(s)
- Jun-Yan Liu
- Department of Entomology and UCD Cancer Research Center, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
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106
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Soluble epoxide hydrolase plays an essential role in angiotensin II-induced cardiac hypertrophy. Proc Natl Acad Sci U S A 2009; 106:564-9. [PMID: 19126686 DOI: 10.1073/pnas.0811022106] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pathophysiological cardiac hypertrophy is one of the most common causes of heart failure. Epoxyeicosatrienoic acids, hydrolyzed and degraded by soluble epoxide hydrolase (sEH), can function as endothelium-derived hyperpolarizing factors to induce dilation of coronary arteries and thus are cardioprotective. In this study, we investigated the role of sEH in two rodent models of angiotensin II (Ang II)-induced cardiac hypertrophy. The protein level of sEH was elevated in the heart of both spontaneously hypertensive rats and Ang II-infused Wistar rats. Blocking the Ang II type 1 receptor with losartan could abolish this induction. Administration of a potent sEH inhibitor (sEHI) prevented the pathogenesis of the Ang II-induced hypertrophy, as demonstrated by decreased left-ventricular hypertrophy assessed by echocardiography, reduced cardiomyocyte size, and attenuated expression of hypertrophy markers, including atrial natriuretic factor and beta-myosin heavy chain. Because sEH elevation was not observed in exercise- or norepinephrine-induced hypertrophy, the sEH induction was closely associated with Ang II-induced hypertrophy. In vitro, Ang II upregulated sEH and hypertrophy markers in neonatal cardiomyocytes isolated from rat and mouse. Expression of these marker genes was elevated with adenovirus-mediated sEH overexpression but decreased with sEHI treatment. These results were supported by studies in neonatal cardiomyocytes from sEH(-/-) mice. Our results suggest that sEH is specifically upregulated by Ang II, which directly mediates Ang II-induced cardiac hypertrophy. Thus, pharmacological inhibition of sEH would be a useful approach to prevent and treat Ang II-induced cardiac hypertrophy.
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107
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Mustafa S, Sharma V, McNeill JH. Insulin resistance and endothelial dysfunction: Are epoxyeicosatrienoic acids the link? Exp Clin Cardiol 2009; 14:e41-e50. [PMID: 19675820 PMCID: PMC2722460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Accepted: 04/30/2009] [Indexed: 05/28/2023]
Abstract
Epoxyeicosatrienoic acids (EETs), the cytochrome P450 epoxygenase metabolites of arachidonic acid, are potent vasodilators and are believed to be the endothelium-derived hyperpolarizing factor in a number of vascular beds. In addition, EETs may play a role in the secretion and action of insulin and the metabolism of carbohydrates and lipids. Pharmacological manipulation of EETs may be a useful therapeutic approach for disease states such as hypertension, diabetes mellitus and the metabolic syndrome. EET mimetics and antagonists and drugs that increase EET synthesis or decrease their degradation are currently under investigation. The cellular mechanism of action of EETs appears to be complex and is being intensively studied by a number of investigators. In the present article, EET production, metabolism, isomerism and vasodilatory effects will be reviewed and potential mechanisms of action discussed. The role of EETs in insulin secretion and sensitivity and their implication in diabetes mellitus and the metabolic syndrome will also be reviewed. Drugs affecting EET bioavailability and action may be promising agents to use to treat hypertension/insulin resistance. The effects of these agents in experimental vascular disorders will also be discussed.
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Affiliation(s)
| | | | - John H McNeill
- Correspondence: Dr John H McNeill, Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, 2146 East Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z3. Telephone 604-822-9373, fax 604-822-8001, e-mail
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108
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EnayetAllah AE, Luria A, Luo B, Tsai HJ, Sura P, Hammock BD, Grant DF. Opposite regulation of cholesterol levels by the phosphatase and hydrolase domains of soluble epoxide hydrolase. J Biol Chem 2008; 283:36592-8. [PMID: 18974052 DOI: 10.1074/jbc.m806315200] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Soluble epoxide hydrolase (sEH) is a bifunctional enzyme with two catalytic domains: a C-terminal epoxide hydrolase domain and an N-terminal phosphatase domain. Epidemiology and animal studies have attributed a variety of cardiovascular and anti-inflammatory effects to the C-terminal epoxide hydrolase domain. The recent association of sEH with cholesterol-related disorders, peroxisome proliferator-activated receptor activity, and the isoprenoid/cholesterol biosynthesis pathway additionally suggest a role of sEH in regulating cholesterol metabolism. Here we used sEH knock-out (sEH-KO) mice and transfected HepG2 cells to evaluate the phosphatase and hydrolase domains in regulating cholesterol levels. In sEH-KO male mice we found a approximately 25% decrease in plasma total cholesterol as compared with wild type (sEH-WT) male mice. Consistent with plasma cholesterol levels, liver expression of HMG-CoA reductase was found to be approximately 2-fold lower in sEH-KO male mice. Additionally, HepG2 cells stably expressing human sEH with phosphatase only or hydrolase only activity demonstrate independent and opposite roles of the two sEH domains. Whereas the phosphatase domain elevated cholesterol levels, the hydrolase domain lowered cholesterol levels. Hydrolase inhibitor treatment in sEH-WT male and female mice as well as HepG2 cells expressing human sEH resulted in higher cholesterol levels, thus mimicking the effect of expressing the phosphatase domain in HepG2 cells. In conclusion, we show that sEH regulates cholesterol levels in vivo and in vitro, and we propose the phosphatase domain as a potential therapeutic target in hypercholesterolemia-related disorders.
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Affiliation(s)
- Ahmed E EnayetAllah
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269-3092, USA
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109
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Sanchez-Mejia RO, Newman JW, Toh S, Yu GQ, Zhou Y, Halabisky B, Cissé M, Scearce-Levie K, Cheng IH, Gan L, Palop JJ, Bonventre JV, Mucke L. Phospholipase A2 reduction ameliorates cognitive deficits in a mouse model of Alzheimer's disease. Nat Neurosci 2008; 11:1311-8. [PMID: 18931664 PMCID: PMC2597064 DOI: 10.1038/nn.2213] [Citation(s) in RCA: 275] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Accepted: 09/17/2008] [Indexed: 11/09/2022]
Abstract
Neuronal expression of familial Alzheimer's disease-mutant human amyloid precursor protein (hAPP) and hAPP-derived amyloid-beta (Abeta) peptides causes synaptic dysfunction, inflammation and abnormal cerebrovascular tone in transgenic mice. Fatty acids may be involved in these processes, but their contribution to Alzheimer's disease pathogenesis is uncertain. We used a lipidomics approach to generate a broad profile of fatty acids in brain tissues of hAPP-expressing mice and found an increase in arachidonic acid and its metabolites, suggesting increased activity of the group IV isoform of phospholipase A(2) (GIVA-PLA(2)). The levels of activated GIVA-PLA(2) in the hippocampus were increased in individuals with Alzheimer's disease and in hAPP mice. Abeta caused a dose-dependent increase in GIVA-PLA(2) phosphorylation in neuronal cultures. Inhibition of GIVA-PLA(2) diminished Abeta-induced neurotoxicity. Genetic ablation or reduction of GIVA-PLA(2) protected hAPP mice against Abeta-dependent deficits in learning and memory, behavioral alterations and premature mortality. Inhibition of GIVA-PLA(2) may be beneficial in the treatment and prevention of Alzheimer's disease.
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Affiliation(s)
- Rene O Sanchez-Mejia
- Gladstone Institute of Neurological Disease, San Francisco, California 94158, USA.
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110
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Li H, Xie Z, Lin J, Song H, Wang Q, Wang K, Su M, Qiu Y, Zhao T, Song K, Wang X, Zhou M, Liu P, Zhao G, Zhang Q, Jia W. Transcriptomic and Metabonomic Profiling of Obesity-Prone and Obesity-Resistant Rats under High Fat Diet. J Proteome Res 2008; 7:4775-83. [DOI: 10.1021/pr800352k] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Houkai Li
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Zuoquan Xie
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Jingchao Lin
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Huaiguang Song
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Qi Wang
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Ke Wang
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Mingming Su
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Yunping Qiu
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Tie Zhao
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Kai Song
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Xiaoyan Wang
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Mingmei Zhou
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Ping Liu
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Guoping Zhao
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Qinghua Zhang
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
| | - Wei Jia
- School of Pharmacy and Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, PRC, State Key Laboratory of Medical Genomics and Shanghai Institute of Hematology Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PRC, National Engineering Center for Biochip at Shanghai, 201203, PRC, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, PRC, and Department of Nutrition, University of North Carolina at Greensboro, North
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111
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Fife KL, Liu Y, Schmelzer KR, Tsai HJ, Kim IH, Morisseau C, Hammock BD, Kroetz DL. Inhibition of soluble epoxide hydrolase does not protect against endotoxin-mediated hepatic inflammation. J Pharmacol Exp Ther 2008; 327:707-15. [PMID: 18815352 DOI: 10.1124/jpet.108.142398] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Epoxyeicosatrienoic acids (EETs) are derived from cytochrome P450-catalyzed epoxygenation of arachidonic acid and have emerged as important mediators of numerous biological effects. The major elimination pathway for EETs is through soluble epoxide hydrolase (sEH)-catalyzed metabolism to dihydroxyeicosatrienoic acids (DHETs). Based on previous studies showing that EETs have anti-inflammatory effects, we hypothesized that chronic inhibition of sEH would attenuate a lipopolysaccharide (LPS)-induced inflammatory response in vivo. Continuous dosing of the sEH inhibitors 12-(3-adamantan-1-ylureido)-dodecanoic acid (AUDA), a polyethylene glycol ester of AUDA, and 1-adamantan-1-yl-3-(5-(2-(2-ethoxyethoxy)ethoxy)-pentyl)urea resulted in robust exposure to the inhibitor and target engagement, as evidenced by significant increases in plasma EET/DHET ratios following 6 days of inhibitor treatment. However, sEH inhibitor treatment was not associated with an attenuation of LPS-induced inflammatory gene expression in the liver, and AUDA did not protect from LPS-induced neutrophil infiltration. Furthermore, Ephx2-/-mice that lack sEH expression and have significantly increased plasma EET/DHET ratios were not protected from LPS-induced inflammatory gene expression or neutrophil accumulation in the liver. LPS did have an effect on sEH expression and function, as evident from a significant down-regulation of Ephx2 mRNA and a significant shift in plasma EET/DHET ratios 4 h after LPS treatment. In conclusion, there was no evidence that increasing EET levels in vivo could modulate an LPS-induced inflammatory response in the liver. However, LPS did have significant effects on plasma eicosanoid levels and hepatic Ephx2 expression, suggesting that in vivo EET levels are modulated in response to an inflammatory signal.
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Affiliation(s)
- Kimberly L Fife
- Department of Biopharmaceutical Sciences, University of California, San Francisco, California, USA
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112
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Wang L, Gill R, Pedersen TL, Higgins LJ, Newman JW, Rutledge JC. Triglyceride-rich lipoprotein lipolysis releases neutral and oxidized FFAs that induce endothelial cell inflammation. J Lipid Res 2008; 50:204-13. [PMID: 18812596 DOI: 10.1194/jlr.m700505-jlr200] [Citation(s) in RCA: 202] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Triglyceride-rich lipoprotein (TGRL) lipolysis products provide a pro-inflammatory stimulus that can alter endothelial barrier function. To probe the mechanism of this lipolysis-induced event, we evaluated the pro-inflammatory potential of lipid classes derived from human postprandial TGRL by lipoprotein lipase (LpL). Incubation of TGRL with LpL for 30 min increased the saturated and unsaturated FFA content of the incubation solutions significantly. Furthermore, concentrations of the hydroxylated linoleates 9-hydroxy ocatadecadienoic acid (9-HODE) and 13-HODE were elevated by LpL lipolysis, more than other measured oxylipids. The FFA fractions elicited pro-inflammatory responses inducing TNFalpha and intracellular adhesion molecule expression and reactive oxygen species (ROS) production in human aortic endothelial cells (HAECs). The FFA-mediated increase in ROS was blocked by both the cytochrome P450 2C9 inhibitor sulfaphenazole and NADPH oxidase inhibitors. Compared with linoleate, 13-HODE was found to be a more potent inducer of ROS production in HAECs, an activity that was insensitive to both NADPH oxidase and cytochrome P450 inhibitors. Therefore, although the oxidative metabolism of FFA in endothelial cells can produce inflammatory responses, TGRL lipolysis can also release preformed mediators of oxidative stress (e.g., HODEs) that may influence endothelial cell function in vivo by stimulating intracellular ROS production.
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Affiliation(s)
- Limin Wang
- Division of Endocrinology, Clinical Nutrition, and Vascular Medicine, University of California, Davis, Davis, CA, USA.
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113
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Keserü B, Barbosa-Sicard E, Popp R, Fisslthaler B, Dietrich A, Gudermann T, Hammock BD, Falck JR, Weissmann N, Busse R, Fleming I. Epoxyeicosatrienoic acids and the soluble epoxide hydrolase are determinants of pulmonary artery pressure and the acute hypoxic pulmonary vasoconstrictor response. FASEB J 2008; 22:4306-15. [PMID: 18725458 DOI: 10.1096/fj.08-112821] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recent findings have indicated a role for cytochrome P-450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) in acute hypoxic pulmonary vasoconstriction (HPV). Given that the intracellular concentration of EETs is determined by the soluble epoxide hydrolase (sEH), we assessed the influence of the sEH and 11,12-EET on pulmonary artery pressure and HPV in the isolated mouse lung. In lungs from wild-type mice, HPV was significantly increased by sEH inhibition, an effect abolished by pretreatment with CYP epoxygenase inhibitors and the EET antagonist 14,15-EEZE. HPV and EET production were greater in lungs from sEH(-/-) mice than from wild-type mice and sEH inhibition had no further effect on HPV, while MSPPOH and 14,15-EEZE decreased the response. 11,12-EET increased pulmonary artery pressure in a concentration-dependent manner and enhanced HPV via a Rho-dependent mechanism. Both 11,12-EET and hypoxia elicited the membrane translocation of a transient receptor potential (TRP) C6-V5 fusion protein, the latter effect was sensitive to 14,15-EEZE. Moreover, while acute hypoxia and 11,12-EET increased pulmonary pressure in lungs from TRPC6(+/-) mice, lungs from TRPC6(-/-) mice did not respond to either stimuli. These data demonstrate that CYP-derived EETs are involved in HPV and that EET-induced pulmonary contraction under normoxic and hypoxic conditions involves a TRPC6-dependent pathway.
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Affiliation(s)
- Benjamin Keserü
- Vascular Signalling Group, Institut für Kardiovaskuläre Physiologie, Goethe-Universität Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
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Soluble epoxide hydrolase is a susceptibility factor for heart failure in a rat model of human disease. Nat Genet 2008; 40:529-37. [PMID: 18443590 DOI: 10.1038/ng.129] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Accepted: 01/23/2008] [Indexed: 11/08/2022]
Abstract
We aimed to identify genetic variants associated with heart failure by using a rat model of the human disease. We performed invasive cardiac hemodynamic measurements in F2 crosses between spontaneously hypertensive heart failure (SHHF) rats and reference strains. We combined linkage analyses with genome-wide expression profiling and identified Ephx2 as a heart failure susceptibility gene in SHHF rats. Specifically, we found that cis variation at Ephx2 segregated with heart failure and with increased transcript expression, protein expression and enzyme activity, leading to a more rapid hydrolysis of cardioprotective epoxyeicosatrienoic acids. To confirm our results, we tested the role of Ephx2 in heart failure using knockout mice. Ephx2 gene ablation protected from pressure overload-induced heart failure and cardiac arrhythmias. We further demonstrated differential regulation of EPHX2 in human heart failure, suggesting a cross-species role for Ephx2 in this complex disease.
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Zhang W, Otsuka T, Sugo N, Ardeshiri A, Alhadid YK, Iliff JJ, DeBarber AE, Koop DR, Alkayed NJ. Soluble epoxide hydrolase gene deletion is protective against experimental cerebral ischemia. Stroke 2008; 39:2073-8. [PMID: 18369166 DOI: 10.1161/strokeaha.107.508325] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Cytochrome P450 epoxygenase metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs). EETs are produced in the brain and perform important biological functions, including vasodilation and neuroprotection. However, EETs are rapidly metabolized via soluble epoxide hydrolase (sEH) to dihydroxyeicosatrienoic acids (DHETs). We tested the hypothesis that sEH gene deletion is protective against focal cerebral ischemia through enhanced collateral blood flow. METHODS sEH knockout (sEHKO) mice with and without EETs antagonist 14, 15 epoxyeicosa-5(Z)-enoic acid (EEZE) were subjected to 2-hour middle cerebral artery occlusion (MCAO), and infarct size was measured at 24 hours of reperfusion and compared to wild-type (WT) mice. Local CBF rates were measured at the end of MCAO using iodoantipyrine (IAP) autoradiography, sEH protein was analyzed by Western blot and immunohistochemistry, and hydrolase activity and levels of EETs/DHETs were measured in brain and plasma using LC-MS/MS and ELISA, respectively. RESULTS sEH immunoreactivity was detected in WT, but not sEHKO mouse brain, and was localized to vascular and nonvascular cells. 14,15-DHET was abundantly present in WT, but virtually absent in sEHKO mouse plasma. However, hydrolase activity and free 14,15-EET in brain tissue were not different between WT and sEHKO mice. Infarct size was significantly smaller, whereas regional cerebral blood flow rates were significantly higher in sEHKO compared to WT mice. Infarct size reduction was recapitulated by 14,15-EET infusion. However, 14,15-EEZE did not alter infarct size in sEHKO mice. CONCLUSIONS sEH gene deletion is protective against ischemic stroke by a vascular mechanism linked to reduced hydration of circulating EETs.
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Affiliation(s)
- Wenri Zhang
- Oregon Health & Science University, Department of Anesthesiology & Peri-Operative Medicine, 3181 SW Sam Jackson Park Road, Portland, OR 97239-3098, USA
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Dreisbach AW, Rice JC, Japa S, Newman JW, Sigel A, Gill RS, Hess AE, Cemo AC, Fonseca JP, Hammock BD, Lertora JJ, Hamm LL. Salt Loading Increases Urinary Excretion of Linoleic Acid Diols and Triols in Healthy Human Subjects. Hypertension 2008; 51:755-61. [DOI: 10.1161/hypertensionaha.107.100123] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increased dietary linoleic acid has been associated with reduced blood pressure in clinical and animal studies possibly mediated by prostaglandins. Urinary linoleate and prostaglandin metabolite excretion were investigated in subjects exposed to a salt-loading/salt-depletion regimen. Twelve healthy subjects were recruited from the New Orleans population (before Hurricaine Katrina) and admitted to the Tulane-Louisiana State University-Charity Hospital General Clinical Research Center after a 5-day outpatient lead-in phase on a 160-mmol sodium diet. On inpatient day 1, the subjects were maintained on the 160-mmol sodium diet, and a 24-hour urine specimen was collected. On day 2, the subjects received 2 L of IV normal saline over 4 hours and continued on a 160-mmol Na
+
diet (total: 460 mmol of sodium). Two 12-hour urine collections were obtained. On day 3, the subjects received three 40-mg oral doses of furosemide, two 12-hour urine collections were obtained, and the subjects were given a 10-mmol sodium diet. Urinary oxidized lipids were measured by high-performance liquid chromatography-tandem quadrupole mass spectroscopy. The excretion of the urinary linoleate metabolites, dihydroxyoctadecamonoenoic acids, and trihydroxyoctadecamonoenoic acids increased significantly during intravenous salt loading as compared with day 1 and the salt-depleted periods. The urinary excretion of 6-keto- prostaglandin F1α was unaffected by salt loading but was dramatically increased 7- to 10-fold by salt depletion. Prostaglandin E2 excretion was positively correlated with sodium excretion. The salt-stimulated production of linoleic acid diols and triols may inhibit tubular sodium reabsorption, thereby assisting in the excretion of the sodium load.
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Affiliation(s)
- Albert W. Dreisbach
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Janet C. Rice
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Shanker Japa
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - John W. Newman
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Aster Sigel
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Rajan S. Gill
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Arthur E. Hess
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Angela C. Cemo
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Juan P. Fonseca
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Bruce D. Hammock
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - Juan J.L. Lertora
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
| | - L. Lee Hamm
- From the Department of Medicine (A.W.D., S.J., A.S., A.E.H., J.P.F., J.J.L.L., L.L.H.), Tulane Health Science Center, New Orleans, La; Department of Biostatistics (J.C.R.), Tulane School of Public Health, New Orleans, La; Tulane-Louisiana State University-Charity Hospital General Clinical Research Center (S.J., A.C.C., J.J.L.L.), New Orleans; Departments of Entomology (J.W.N., R.S.G., B.D.H.) and Nutrition (J.W.N., R.S.G.), University of California, Davis; Western Human Nutrition Research Center (J
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Chiamvimonvat N, Ho CM, Tsai HJ, Hammock BD. The soluble epoxide hydrolase as a pharmaceutical target for hypertension. J Cardiovasc Pharmacol 2007; 50:225-37. [PMID: 17878749 DOI: 10.1097/fjc.0b013e3181506445] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The soluble epoxide hydrolase appears to be a promising target for the development of antihypertensive therapies based on a previously unexplored mechanism of action. Epoxide hydrolases are enzymes that add water to three membered cyclic ethers known as epoxides. The soluble epoxide hydrolase in mammalian systems (sEH) is a member of the alpha/beta-hydrolase fold family of enzymes and it shows a high degree of selectivity for epoxides of fatty acids. The regioisomeric epoxides of arachidonic acid or epoxyeicosanoids (EETs) are particularly good substrates. These EETs appear to be major components of the endothelium-derived hyperpolarizing factors (EDHFs). As such, EETs cause vasodilation and reduce blood pressure. The EETs also are strongly anti-inflammatory and analgesic. By inhibiting sEH, the increase in circulating EETs leads to a reduction in blood pressure in a number of animal models. Potent transition state mimic inhibitors have been developed for the sEH. Some of these sEH inhibitors (sEHIs) show nanomolar to picomolar potency and good pharmacokinetic properties. Because of their unique mode of action they show promise in treating hypertension while reducing problems with end organ failure, vascular inflammation and diabetes. Indeed, the anti-inflammatory properties of the sEHI may make them particularly suitable for treating hypertension in patients with other concomitant metabolic syndromes. They are more potent on a molar basis than most nonsteroidal anti-inflammatory drugs (NSAIDs) in reducing PGE2 in inflammation models, they strongly synergize with NSAIDs, and appear to ameliorate apparently unfavorable eicosanoid profiles associated with some cyclo-oxygenase-2 inhibitors.
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Affiliation(s)
- Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, CA 95616, USA
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Hutchens MP, Nakano T, Dunlap J, Traystman RJ, Hurn PD, Alkayed NJ. Soluble epoxide hydrolase gene deletion reduces survival after cardiac arrest and cardiopulmonary resuscitation. Resuscitation 2007; 76:89-94. [PMID: 17728042 PMCID: PMC2585367 DOI: 10.1016/j.resuscitation.2007.06.031] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2007] [Revised: 06/19/2007] [Accepted: 06/25/2007] [Indexed: 10/22/2022]
Abstract
The P450 eicosanoids epoxyeicosatrienoic acids (EETs) are produced by cytochrome P450 arachidonic acid epoxygenases and metabolized through multiple pathways, including soluble epoxide hydrolase (sEH). Pharmacological inhibition and gene deletion of sEH protect against ischemia/reperfusion injury in brain and heart, and against hypertension-related end-organ damage in kidney. We tested the hypothesis that sEH gene deletion improves survival, recovery of renal function and pathologic ischemic renal damage following transient whole-body ischemia induced by cardiac arrest (CA) and resuscitation. Mice with targeted deletion of sEH (sEH knockout, sEHKO) and C57Bl/6 wild-type control mice were subjected to 10-min CA, followed by cardiopulmonary resuscitation (CPR). Survival in wild-type mice was 93% and 80% at 10 min and 24 h after CA/CPR (n=15). Unexpectedly, survival in sEHKO mice was significantly lower than WT. Only 56% of sEHKO mice survived for 10 min (n=15, p=0.014 compared to WT) and no mice survived for 24 h after CA/CPR (p<0.0001 versus WT). We conclude that sEH plays an important role in cardiovascular regulation, and that reduced sEH levels or function reduces survival from cardiac arrest.
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Affiliation(s)
- Michael P Hutchens
- Department of Anesthesiology & Peri-Operative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Pk. Rd., UHS-2, Portland, OR 97239-3098, United States.
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Newman JW, Kaysen GA, Hammock BD, Shearer GC. Proteinuria increases oxylipid concentrations in VLDL and HDL but not LDL particles in the rat. J Lipid Res 2007; 48:1792-800. [PMID: 17496268 DOI: 10.1194/jlr.m700146-jlr200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously established that proteinuria alters the apolipoprotein content of lipoproteins. This study was conducted to establish whether proteinuria also alters the concentrations of oxidized lipids within lipoprotein density fractions. To this end, we induced passive Heymann nephritis in Sprague Dawley rats and measured an array of alkaline-stable oxylipids in VLDL, LDL, and HDL particles. Proteinuria increased the total oxylipid amounts in the HDL and VLDL fractions. More importantly, these levels were increased when expressed per unit lipoprotein protein, indicating that the oxidized lipid load per particle was increased. Epoxides and diols increased approximately 2-fold in HDL and approximately 5-fold in VLDL, whereas LDL showed approximately 2-fold decreases. The hydroxyeicosatetraenoic acids and hydroxyoctadecadienoic acids (HODEs) increased >4-fold in HDL and >20-fold in VLDL, whereas LDL showed approximately 2-fold decreases in the HODEs. Therefore, nephrotic syndrome alters the lipoprotein oxylipid composition independently of an increase in total lipoprotein levels. These proteinuria-induced changes may be associated with the cardiovascular risk of lipoprotein oxidation.
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Affiliation(s)
- John W Newman
- Western Human Nutrition Research Center, United States Department of Agriculture, USA.
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