Publications by authors named "Vijaya L Manthati"

19-Hydroxyeicosatetraenoic acid (19-HETE, 1), a metabolically and chemically labile cytochrome P450 eicosanoid, has diverse biological activities including antagonism of the vasoconstrictor 20-hydroxyeicosatetraenoic acid (20-HETE, 2). A SAR study was conducted to develop robust analogs of 1 with improved in vitro and in vivo efficacy. Analogs were screened in vitro for inhibition of 20-HETE-induced sensitization of rat renal preglomerular microvessels toward phenylephrine and demonstrated to normalize the blood pressure of male Cyp4a14(-/-) mice that display androgen-driven, 20-HETE-dependent hypertension.

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Aim: Imbalances in cytochrome P450 (CYP)-dependent eicosanoid formation may play a central role in ischemic acute kidney injury (AKI). We reported previously that inhibition of 20-hydroxyeicosatetraenoic acid (20-HETE) action ameliorated ischemia/reperfusion (I/R)-induced AKI in rats. Now we tested the hypothesis that enhancement of epoxyeicosatrienoic acid (EET) actions may counteract the detrimental effects of 20-HETE and prevent the initiation of AKI.

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Epoxyeicosatrienoic acids (EETs) contribute to blood pressure regulation leading to the concept that EETs can be therapeutically targeted for hypertension and the associated end organ damage. In the present study, we investigated anti-hypertensive and kidney protective actions of an EET analog, EET-B in angiotensin II (ANG II)-induced hypertension. EET-B was administered in drinking water for 14 days (10 mg/kg/d) and resulted in a decreased blood pressure elevation in ANG II hypertension.

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The cytochrome P450 eicosanoid 14,15-epoxyeicosa-5,8,11-trienoic acid (14,15-EET) is a powerful endogenous autacoid that has been ascribed an impressive array of physiologic functions including regulation of blood pressure. Because 14,15-EET is chemically and metabolically labile, structurally related surrogates containing epoxide bioisosteres were introduced and have become useful in vitro pharmacologic tools but are not suitable for in vivo applications. A new generation of EET mimics incorporating modifications to the carboxylate were prepared and evaluated for vasorelaxation and inhibition of soluble epoxide hydrolase (sEH).

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In the kidney, 20-hydroxyeicosatetraenoic acid (20-HETE) is a primary cytochrome P450 4 (Cyp4)-derived eicosanoid that enhances vasoconstriction of renal vessels and induces hypertension, renal tubular cell hypertrophy, and podocyte apoptosis. Hypertension and podocyte injury contribute to diabetic nephropathy and are strong predictors of disease progression. In this study, we defined the mechanisms whereby 20-HETE affects the progression of diabetic nephropathy.

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Epoxyeicosatrienoic acids (EETs), lipid mediators produced by cytochrome P450 epoxygenases, regulate inflammation, angiogenesis, and vascular tone. Despite pleiotropic effects on cells, the role of these epoxyeicosanoids in normal organ and tissue regeneration remains unknown. EETs are produced predominantly in the endothelium.

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We have previously demonstrated that a stable synthetic analog of 20-hydroxyeicosatetraenoic acid (20-HETE), N-[20-hydroxyeicosa-5(Z),14(Z)-dienoyl]glycine (5,14-HEDGE), prevents vascular hyporeactivity, hypotension, tachycardia, and inflammation in rats treated with lipopolysaccharide (LPS) and mortality in endotoxemic mice. These changes were attributed to decreased production of inducible nitric oxide (NO) synthase (iNOS)-derived NO, cyclooxygenase (COX)-2-derived vasodilator prostanoids, and proinflammatory mediators associated with increased cyctochrome P450 (CYP) 4A1-derived 20-HETE and CYP2C23-dependent antiinflammatory mediator formation. The aim of this study was to determine whether decreased expression and activity of iNOS, soluble guanylyl cyclase (sGC), protein kinase G (PKG), COX-2, gp91(phox) (NOX2; a superoxide generating NOX enzyme), and peroxynitrite production associated with increased expression of COX-1 and CYP4A1 and 20-HETE formation in renal and cardiovascular tissues of rats contributes to the effect of 5,14-HEDGE to prevent vasodilation, hypotension, tachycardia, and inflammation in response to systemic administration of LPS.

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Although the mechanism underlying the effect of androgen on BP and cardiovascular disease is not well understood, recent studies suggest that 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE), a primary cytochrome P450 4 (Cyp4)-derived eicosanoid, may mediate androgen-induced hypertension. Here, treatment of normotensive mice with 5α-dihydrotestosterone increased BP and induced both Cyp4a12 expression and 20-HETE levels in preglomerular microvessels. Administration of a 20-HETE antagonist prevented and reversed the effects of dihydrotestosterone on BP.

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The present study tested the hypothesis that the Dahl SS (salt-sensitive) rat has vascular dysfunction due, in part, to the up-regulation of the CYP4A/20-HETE (cytochrome P450 ω-hydroxylase 4A)/20-hydroxyeicosatetraenoic acid) system. To assess the role of vascular 20-HETE, SS rats were compared with SS-5(BN) consomic rats, carrying CYP4A alleles on chromosome 5 from the normotensive BN (Brown Norway) introgressed on to the SS genetic background. Cerebral arteries from SS-5(BN) rats had less CYP4A protein than arteries from SS rats fed either NS (normal-salt, 0.

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Epoxyeicosatrienoic acids (EETs) are small molecules produced by cytochrome P450 epoxygenases. They are lipid mediators that act as autocrine or paracrine factors to regulate inflammation and vascular tone. As a result, drugs that raise EET levels are in clinical trials for the treatment of hypertension and many other diseases.

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Mannose-6-phosphate (M6P) is an essential precursor for mannosyl glycoconjugates, including lipid-linked oligosaccharides (LLO; glucose(3)mannose(9)GlcNAc(2)-P-P-dolichol) used for protein N-glycosylation. In permeabilized mammalian cells, M6P also causes specific LLO cleavage. However, the context and purpose of this paradoxical reaction are unknown.

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Endothelium-derived epoxyeicosatrienoic acids (EETs) relax vascular smooth muscle by activating potassium channels and causing membrane hyperpolarization. Recent evidence suggests that EETs act via a membrane binding site or receptor. To further characterize this binding site or receptor, we synthesized 20-iodo-14,15-epoxyeicosa-8(Z)-enoyl-3-azidophenylsulfonamide (20-I-14,15-EE8ZE-APSA), an EET analogue with a photoactive azido group.

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Cytochrome P450 (CYP) epoxygenases, CYP2C8, 2C9 and 2J2 mRNA 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 EET synthesis by a selective CYP epoxygenase inhibitor (N-methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide [MS-PPOH]) inhibited tonic (basal) invasion and migration (motility) while exogenously added EET induced cell motility in a concentration-dependent manner.

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Human mesenchymal stem cells (MSCs) expressed substantial levels of CYP2J2, a major CYP450 involved in epoxyeicosatrienoic acid (EET) formation. MSCs synthesized significant levels of EETs (65.8 ± 5.

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Epoxyeicosatrienoic acids (EETs) contribute importantly to the regulation of vascular tone and blood pressure control. The purpose of this study was to develop stable EET analogs and test their in vivo blood pressure lowering effects in hypertensive rats. Using the pharmacophoric moiety of EETs, ether EET analogs were designed with improved solubility and resistance to auto-oxidation and metabolism by soluble epoxide hydrolase.

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