Epoxygenase Cyp2c44 Regulates Hepatic Lipid Metabolism and Insulin Signaling by Controlling FATP2 Localization and Activation of the DAG/PKCδ Axis.

Cytochrome P450 epoxygenase Cyp2c44, a murine epoxyeicosatrienoic acid (EET)-producing enzyme, promotes insulin sensitivity, and Cyp2c44-/- mice show hepatic insulin resistance. Because insulin resistance leads to hepatic lipid accumulation and hyperlipidemia, we hypothesized that Cyp2c44 regulates hepatic lipid metabolism. Standard chow diet (SCD)-fed male Cyp2c44-/- mice had significantly decreased EET levels and increased hepatic and plasma lipid levels compared with wild-type mice.

Cardioprotective Action of a Novel Synthetic 19,20-EDP Analog Is Sirt Dependent.

Mounting evidence suggests that cytochrome P450 epoxygenase-derived metabolites of docosahexaenoic acid, called epoxydocosapentaenoic acids (EDPs), limit mitochondrial damage after cardiac injury. In particular, the 19,20-EDP regioisomer has demonstrated potent cardioprotective action. Thus, we investigated our novel synthetic 19,20-EDP analog SA-22 for protection against cardiac ischemia-reperfusion (IR) injury.

20-Hydroxyeicosatetraenoic acid (20-HETE): Bioactions, receptors, vascular function, cardiometabolic disease and beyond.

Vascular function is dynamically regulated and dependent on a bevy of cell types and factors that work in concert across the vasculature. The vasoactive eicosanoid, 20-Hydroxyeicosatetraenoic acid (20-HETE) is a key player in this system influencing the sensitivity of the vasculature to constrictor stimuli, regulating endothelial function, and influencing the renin angiotensin system (RAS), as well as being a driver of vascular remodeling independent of blood pressure elevations. Several of these bioactions are accomplished through the ligand-receptor pairing between 20-HETE and its high-affinity receptor, GPR75.

Effect of Chronically Suppressed Plasma Angiotensin II on Regulation of the CYP4A/20-HETE Pathway in the Dahl Salt-Sensitive Rat.

In Dahl salt-sensitive (SS) rats, impaired vascular relaxation can be restored by: () minipump infusion of a low (sub-pressor) dose of angiotensin II (ANG II) to restore physiological levels of plasma ANG II, () inhibition of 20-HETE production, and () introgression of a normally functioning renin allele from the Brown Norway rat (SS-13 consomic rat). Unlike SS rats, SS-13 rats have normal levels of ANG II on a normal-salt diet and suppressed ANG II on a high-salt (HS) diet. This study tested whether chronically low ANG II levels in SS rats upregulate cytochrome P450-4A (CYP4A) increasing the production of the vasoconstrictor 20-HETE.

20-HETE/GPR75 pairing modulates the expression and transcriptional activity of the androgen receptor in androgen-sensitive prostate cancer cells.

The androgen receptor (AR) and AR-driven genes are crucial in normal and neoplastic prostate tissue. Previous results showed a link between 20-hydroxyeicosatetraenoic acid (20-HETE) production and AR-driven prostate cancer (PCa) progression. This study aims to describe the contribution of GPR75, 20-HETE membrane receptor, in 20-HETE-mediated expression and transcriptional activity of AR in PCa.

Directed, Remote Dirhodium C(sp)-H Functionalization, Desaturative Annulation, and Desaturation.

Iminodirhodium reactive intermediates generated from -tosyloximes using Rh(esp) in CHCl at rt were exploited for an agile trichotomy of challenging transformations: (1) remote using an exceptionally broad diversity of inorganic and organic nucleophiles including several unconventional examples, for example, ethers and acyl silanes; (2) , a biomimetic 1,3-methylene C-C ring-closure with an overall loss of two hydrogens; and (3) directed desaturation for the acceptor-less, regioselective creation of γ,δ- or γ,δ,ε,ζ-olefins. Compared with typical iminyl transition-metal-mediated and 1,5-hydrogen atom-transfer (1,5-HAT) processes, iminodirhodium intermediates are largely underexplored, especially with respect to C(sp)-H centers and, yet, have the potential to be transformative by virtue of their substrate breadth, regiocontrol, and elusive reaction modality. A substrate scope includes benzylic, allylic, propargylic, tertiary, and α-alkyloxy centers.

Site-selective amination and/or nitrilation metal-free C(sp)-C(sp) cleavage of benzylic and allylic alcohols.

Benzylic/allylic alcohols are converted site-selective C(sp)-C(sp) cleavage to value-added nitrogenous motifs, , anilines and/or nitriles as well as N-heterocycles, utilizing commercial hydroxylamine--sulfonic acid (HOSA) and EtN in an operationally simple, one-pot process. Notably, cyclic benzylic/allylic alcohols undergo bis-functionalization with attendant increases in architectural complexity and step-economy.

Activation of GPR75 Signaling Pathway Contributes to the Effect of a 20-HETE Mimetic, 5,14-HEDGE, to Prevent Hypotensive and Tachycardic Responses to Lipopolysaccharide in a Rat Model of Septic Shock.

The orphan receptor, G protein-coupled receptor (GPR) 75, which has been shown to mediate various effects of 20-hydroxyeicosatetraenoic acid (20-HETE), is considered as a therapeutic target in the treatment of cardiovascular diseases in which changes in the production of 20-HETE play a key role in their pathogenesis. Our previous studies showed that 20-HETE mimetic, N -(20-hydroxyeicosa-5[Z],14[Z]-dienoyl)glycine (5,14-HEDGE), protects against vascular hyporeactivity, hypotension, tachycardia, and arterial inflammation induced by lipopolysaccharide (LPS) in rats. This study tested the hypothesis that the GPR75 signaling pathway mediates these effects of 5,14-HEDGE in response to systemic exposure to LPS.

Neutrophil-Derived Myeloperoxidase and Hypochlorous Acid Critically Contribute to 20-Hydroxyeicosatetraenoic Acid Increases that Drive Postischemic Angiogenesis.

Compensatory angiogenesis is an important adaptation for recovery from critical ischemia. We recently identified 20-hydroxyeicosatetraenoic acid (20-HETE) as a novel contributor of ischemia-induced angiogenesis. However, the precise mechanisms by which ischemia promotes 20-HETE increases that drive angiogenesis are unknown.

Epoxyeicosatrienoic Acid Analog and 20-HETE Antagonist Combination Prevent Hypertension Development in Spontaneously Hypertensive Rats.

Numerous studies indicate a significant role for cytochrome P-450-dependent arachidonic acid metabolites in blood pressure regulation, vascular tone, and control of renal function. Epoxyeicosatrienoic acids (EETs) exhibit a spectrum of beneficial effects, such as vasodilatory activity and anti-inflammatory, anti-fibrotic, and anti-apoptotic properties. 20-Hydroxyeicosatetraenoic acid (20-HETE) is a potent vasoconstrictor that inhibits sodium reabsorption in the kidney.

Blockade of 20-hydroxyeicosatetraenoic acid receptor lowers blood pressure and alters vascular function in mice with smooth muscle-specific overexpression of CYP4A12-20-HETE synthase.

Objective: 20-Hydroxyeicosatetraenoic acid (20-HETE) is a vasoactive eicosanoid exhibiting effects on vascular smooth muscle cell (VSMC) via G-protein coupled receptor 75 (GPR75) and include stimulation of contractility, migration, and growth. We examined whether VSMC-targeted overexpression of CYP4A12, the primary 20-HETE-producing enzyme in mice, is sufficient to promote hypertension.

Methods: Mice with VSM-specific Cyp4a12 overexpression (Myh11-4a12) and their littermate controls (WT) were generated by crossbreeding Cyp4a12-floxed with Myh11-Cre mice.

EET Analog Treatment Improves Insulin Signaling in a Genetic Mouse Model of Insulin Resistance.

We previously showed that global deletion of the cytochrome P450 epoxygenase Cyp2c44, a major epoxyeicosatrienoic acid (EET) producing enzyme in mice, leads to impaired hepatic insulin signaling resulting in insulin resistance. This finding led us to investigate whether administration of a water soluble EET analog restores insulin signaling in vivo in Cyp2c44(-/-) mice and investigated the underlying mechanisms by which this effect is exerted. Cyp2c44(-/-) mice treated with the analog EET-A for 4 weeks improved fasting glucose and glucose tolerance compared to Cyp2c44(-/-) mice treated with vehicle alone.

20-HETE Participates in Intracerebral Hemorrhage-Induced Acute Injury by Promoting Cell Ferroptosis.

Intracerebral hemorrhage (ICH) is a highly fatal type of stroke that leads to various types of neuronal death. Recently, ferroptosis, a form of cell death resulting from iron-dependent lipid peroxide accumulation, was observed in a mouse ICH model. N-hydroxy-N'-(4-n-butyl-2-methylphenyl)-formamidine (HET0016), which inhibits synthesis of the arachidonic acid metabolite 20-hydroxyeicosatetraenoic acid (20-HETE), has shown a protective effect after ICH.

Macrophage 12(S)-HETE Enhances Angiotensin II-Induced Contraction by a BLT2 (Leukotriene B Type-2 Receptor) and TP (Thromboxane Receptor)-Mediated Mechanism in Murine Arteries.

12/15-LO (12/15-lipoxygenase), encoded by gene, metabolizes arachidonic acid to 12(S)-HETE (12-hydroxyeicosatetraenoic acid). Macrophages are the major source of 12/15-LO among immune cells, and 12/15-LO plays a crucial role in development of hypertension. Global - or macrophage-deficient mice are resistant to Ang II (angiotensin II)-induced hypertension.

EET Analog Treatment Improves Insulin Signaling in a Genetic Mouse Model of Insulin Resistance.

We previously showed that global deletion of the cytochrome P450 epoxygenase , a major epoxyeicosatrienoic acid (EET) producing enzyme in mice, leads to impaired hepatic insulin signaling resulting in insulin resistance. This finding led us to investigate whether administration of a water soluble EET analog restores insulin signaling in mice and investigated the underlying mechanisms by which this effect is exerted. mice treated with the analog EET-A for 4 weeks improved fasting glucose and glucose tolerance compared to mice treated with vehicle alone.

Effects of Epoxyeicosatrienoic Acid-Enhancing Therapy on the Course of Congestive Heart Failure in Angiotensin II-Dependent Rat Hypertension: From mRNA Analysis towards Functional In Vivo Evaluation.

This study evaluates the effects of chronic treatment with EET-A, an orally active epoxyeicosatrienoic acid (EETs) analog, on the course of aorto-caval fistula (ACF)-induced heart failure (HF) in Ren-2 transgenic rats (TGR), a model characterized by hypertension and augmented activity of the renin-angiotensin system (RAS). The results were compared with standard pharmacological blockade of the RAS using angiotensin-converting enzyme inhibitor (ACEi). The rationale for employing EET-A as a new treatment approach is based on our findings that apart from increased RAS activity, untreated ACF TGR also shows kidney and left ventricle (LV) tissue deficiency of EETs.

Novel Synthetic Analogues of 19(S/R)-Hydroxyeicosatetraenoic Acid Exhibit Noncompetitive Inhibitory Effect on the Activity of Cytochrome P450 1A1 and 1B1.

Background And Objectives: Cytochrome P450 (CYP) 1A1 and CYP1B1 enzymes play a significant role in the pathogenesis of cancer and cardiovascular diseases (CVD) such as cardiac hypertrophy and heart failure. Previously, we have demonstrated that R- and S-enantiomers of 19-hydroxyeicosatetraenoic acid (19-HETE), an arachidonic acid endogenous metabolite, enantioselectively inhibit CYP1B1. The current study was conducted to test the possible inhibitory effect of novel synthetic analogues of R- and S-enantiomers of 19-HETE on the activity of CYP1A1, CYP1A2, and CYP1B1.

Uncovering the signalling, structure and function of the 20-HETE-GPR75 pairing: Identifying the chemokine CCL5 as a negative regulator of GPR75.

Background And Purpose: The G-protein-coupled receptor GPR75 (Gq) and its ligand, the cytochrome P450-derived vasoactive eicosanoid 20-hydroxyeicosatetraenoic acid (20-HETE), are involved in the activation of pro-inflammatory and hypertensive signalling cascades contributing to diabetes, obesity, vascular dysfunction/remodelling, hypertension and cardiovascular disease. Little is known as to how, where and with what affinity 20-HETE interacts with GPR75.

Experimental Approach: To better understand the pairing of 20-HETE and its receptor (GPR75), we used surface plasmon resonance (SPR) to determine binding affinity/kinetics.

Kidney-Targeted Epoxyeicosatrienoic Acid Analog, EET-F01, Reduces Inflammation, Oxidative Stress, and Cisplatin-Induced Nephrotoxicity.

Although epoxyeicosatrienoic acid (EET) analogs have performed well in several acute and chronic kidney disease models, targeted delivery of EET analogs to the kidney can be reasonably expected to reduce the level of drug needed to achieve a therapeutic effect and obviate possible side effects. For EET analog kidney-targeted delivery, we conjugated a stable EET analog to folic acid via a PEG-diamine linker. Next, we compared the kidney targeted EET analog, EET-F01, to a well-studied EET analog, EET-A.

Early Renal Vasodilator and Hypotensive Action of Epoxyeicosatrienoic Acid Analog (EET-A) and 20-HETE Receptor Blocker (AAA) in Spontaneously Hypertensive Rats.

Cytochrome P450 (CYP-450) metabolites of arachidonic acid: epoxyeicosatrienoic acids (EETs) and 20-hydroxyeicosatetraenoic acid (20-HETE) have established role in regulation of blood pressure (BP) and kidney function. EETs deficiency and increased renal formation of 20-HETE contribute to hypertension in spontaneously hypertensive rats (SHR). We explored the effects of 14,15-EET analog (EET-A) and of 20-HETE receptor blocker (AAA) on BP and kidney function in this model.

Intramolecular N-Me and N-H aminoetherification for the synthesis of -unprotected 3-amino-O-heterocycles.

A mild Rh-catalyzed method for synthesis of cyclic unprotected N-Me and N-H 2,3-aminoethers using an olefin aziridination-aziridine ring-opening domino reaction has been developed. The method is readily applicable to the stereocontrolled synthesis of a variety of 2,3-disubstituted aminoether O-heterocyclic scaffolds, including tetrahydrofurans, tetrahydropyrans and chromanes.

20-HETE interferes with insulin signaling and contributes to obesity-driven insulin resistance.

20-HETE, a metabolite of arachidonic acid produced by Cytochrome P450 (CYP) 4A/4 F, has been implicated in the development of obesity-associated complications such as diabetes and insulin resistance. In this study, we examined whether the acute elevation of 20-HETE levels contributes to the development of diet-driven hyperglycemia and insulin resistance. We employed a conditional transgenic mouse model to overexpress Cyp4a12 (Cyp4a12tg), a murine 20-HETE synthase, together with high fat diet (HFD) feeding.

A Synthetic Epoxydocosapentaenoic Acid Analogue Ameliorates Cardiac Ischemia/Reperfusion Injury: The Involvement of the Sirtuin 3-NLRP3 Pathway.

While survival rates have markedly improved following cardiac ischemia-reperfusion (IR) injury, the resulting heart damage remains an important issue. Preserving mitochondrial quality and limiting NLRP3 inflammasome activation is an approach to limit IR injury, in which the mitochondrial deacetylase sirtuin 3 (SIRT3) has a role. Recent data demonstrate cytochrome P450 (CYP450)-derived epoxy metabolites, epoxydocosapentaenoic acids (EDPs), of docosahexaenoic acid (DHA), attenuate cardiac IR injury.

Cu(OTf)-catalyzed Beckmann Rearrangement of Ketones Using Hydroxylaminesulfonic Acid (HOSA).

The Beckmann Rearrangement (BKR) of ketones to secondary amides often requires harsh reaction conditions that limit its practicality and scope. Herein, we describe the Cu(OTf)-catalyzed BKR of ketones under mild reaction conditions using hydroxylaminesulfonic acid (HOSA), a commercial water soluble aminating agent. This method is compatible with most functional groups and directly provides the desired amides in good to excellent yields.