Karen Wagner

• Ph.D.
• University of California, Davis

[This corrects the article DOI: 10.1371/journal.pone.0266608.].

Aging, which is characterized by enhanced cell senescence and functional decline of tissues, is a major risk factor for many chronic diseases. Accumulating evidence shows that age-related dysfunction in the colon leads to disorders in multiple organs and systemic inflammation. However, the detailed pathological mechanisms and endogenous regulators...

Given the paucity of research surrounding the effect of chronic paraquat on striatal neurotoxicity, there is a need for further investigation into the neurotoxic effects of paraquat in mouse striatum. Furthermore, while previous studies have shown that inhibiting soluble epoxide hydrolase mitigates MPTP-mediated endoplasmic reticulum stress in mous...

Chemotherapy induced peripheral neuropathy (CIPN) is a particularly pernicious form of neuropathy and the associated pain is the primary dose-limiting factor of life-prolonging chemotherapy treatment. The prevalence of CIPN is high and can last long after treatment has been stopped. Currently, late in the COVID-19 pandemic, there are still increase...

Aflatoxin B1 (AFB1) contamination in food and feed leads to severe global health problems. Acting as the frontier immunological barrier, the intestinal mucosa is constantly challenged by exposure to foodborne toxins such as AFB1 via contaminated diets, but the detailed toxic mechanism and endogenous regulators of AFB1 toxicity are still unclear. He...

21 The voltage-gated sodium Na V 1.7 channel plays a key role as a mediator of action 22 potential propagation in C-fiber nociceptors and is an established molecular target for 23 pain therapy. ProTx-II is a potent and moderately selective peptide toxin from tarantula 24 venom that inhibits human Na V 1.7 activation. Here we used available structur...

21 The voltage-gated sodium Na V 1.7 channel plays a key role as a mediator of action 22 potential propagation in C-fiber nociceptors and is an established molecular target for 23 pain therapy. ProTx-II is a potent and moderately selective peptide toxin from tarantula 24 venom that inhibits human Na V 1.7 activation. Here we used available structur...

The voltage-gated sodium NaV1.7 channel plays a key role as a mediator of action potential propagation in C-fiber nociceptors and is an established molecular target for pain therapy. ProTx-II is a potent and moderately selective peptide toxin from tarantula venom that inhibits human NaV1.7 activation. Here we used available structural and experimen...

Purpose: To perform in vivo evaluation of the structural morphology and vascular plexuses of the neurosensory retina and choroid across vertebrate species using swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography (SS-OCTA) imaging. Methods: A custom-built SS-OCT system with an incorporated flexible imaging arm was used to a...

The voltage-gated sodium NaV1.7 channel plays a key role as a mediator of action potential propagation in C-fiber nociceptors and is an established molecular target for pain therapy. ProTx-II is a potent and moderately selective peptide toxin from tarantula venom that inhibits human NaV1.7 activation. Here we used available structural and experimen...

Asthma currently affects more than 339 million people worldwide. In the present preliminary study, we examined the efficacy of a new, inhalable soluble epoxide hydrolase inhibitor (sEHI), 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), to attenuate airway inflammation, mucin secretion, and hyper-responsiveness (AHR) in an ovalbu...

The soluble epoxide hydrolase (sEH) enzyme is a major regulator of bioactive lipids. The enzyme is highly expressed in liver and kidney and modulates levels of endogenous epoxy-fatty acids, which have pleiotropic biological effects including limiting inflammation, neuroinflammation, and hypertension. It has been hypothesized that inhibiting sEH has...

Background Epoxy fatty acids (EpFAs) are cytochrome P450‐dependent derivatives of PUFAs with potent anti‐inflammatory, pro‐resolving properties. However, their activities are extremely short‐lived as soluble epoxide hydrolase (sEH) quickly converts EpFAs to pro‐inflammatory diols. Here we test the hypothesis that inhibition of sEH is a potential th...

There are few novel therapeutic options available for companion animals, and medications rely heavily on repurposed drugs developed for other species. Considering the diversity of species and breeds in companion animal medicine, comprehensive PK exposures in the companion animal patient is often lacking. The purpose of this paper was to assess the...

Adrenic acid (AdA, 22:4) is an ω-6 polyunsaturated fatty acid (PUFA), derived from arachidonic acid. Like other PUFAs, it is metabolized by cytochrome P450s to a group of epoxy fatty acids (EpFAs), epoxydocosatrienoic acids (EDTs). EpFAs are lipid mediators with various beneficial bioactivities, including exertion of analgesia and reduction of endo...

This report describes the development of an orally active analgesic that resolves inflammation and neuropathic pain without the addictive potential of opioids. EC5026 acts on the cytochrome P450 branch of the arachidonate cascade to stabilize epoxides of polyunsaturated fatty acids (EpFA), which are natural mediators that reduce pain, resolve infla...

Chronic pain is a complicated condition which causes substantial physical, emotional, and financial impacts on individuals and society. However, due to high cost, lack of efficacy and safety problems, current treatments are insufficient. There is a clear unmet medical need for safe, nonaddictive and effective therapies in the management of pain. Ep...

Lepidium meyenii (maca), a plant indigenous to the Peruvian Andes, recently has been utilized globally for claimed health or recreational benefits. The search for natural products that inhibit soluble epoxide hydrolase (sEH), with therapeutically relevant potencies and concentrations, led to the present study on bioactive amide secondary metabolite...

The role of lipids in pain signaling is well established and built on decades of knowledge about the pain and inflammation produced by prostaglandin and leukotriene metabolites of cyclooxygenase and lipoxygenase metabolism, respectively. The analgesic properties of other lipid metabolites are more recently coming to light. Lipid metabolites have be...

Bioactive lipid mediators resulting from the metabolism of polyunsaturated fatty acids (PUFA) are controlled by many pathways that regulate the levels of these mediators and maintain homeostasis to prevent disease. PUFA metabolism is driven primarily through three pathways. Two pathways, the cyclooxygenase (COX) and lipoxygenase (LO) enzymatic path...

Soluble epoxide hydrolase (sEH), a novel therapeutic target for neuropathic pain, is a largely cytosolic enzyme that degrades epoxy-fatty acids (EpFAs), an important class of lipid signaling molecules. Many inhibitors of sEH have been reported, and to date, the 1,3-disubstituted urea has the highest affinity reported for the sEH among the central p...

Enzyme linked immunosorbent assays (ELISA) for the detection of soluble epoxide hydrolase (sEH), a key enzyme in the metabolism of fatty acids and a biomarker, may increasingly represent an important diagnostic tool. However, there is a lack of ELISA for mouse sEH quantification, thus resulting in a bottleneck in understanding the pathogenesis of m...

Inhibition of soluble epoxide hydrolase (sEHI) was shown to be potent to reduce the inflammation, lower the blood pressure in hypertension and is being developed for indication of chronic pain treatment. Guiding by in vitro potency screening, pharmacokinetics and in vivo efficacy studies, a potent sEHI (EC5026) is optimized for the followed clinica...

Cytochrome P450 (CYP) metabolism of arachidonic acid (ARA) produces epoxy fatty acids (EpFAs) such as epoxyeicosatrienoic acids (EETs) that are known to exert protective effects in inflammatory disorders. Endogenous EpFAs are further metabolized into corresponding diols by the soluble epoxide hydrolase (sEH). Through inhibition of sEH, many studies...

Effectively treating chronic pain remains a therapeutic challenge in the clinic. Recent evidence has shown the inhibition of the soluble epoxide hydrolase (sEH) to be an effective strategy to limit chronic pain in preclinical models, horses and companion animals. Determining the safety ofsEH inhibition in addition to this demonstrated efficacy is a...

The drug discovery and development process is greatly hampered by difficulties in translating in vitro potency to in vivo efficacy. Recent studies suggest that the long-neglected drug-target residence time parameter complements classical drug affinity parameters (KI, Kd, IC50, or EC50) and is a better predictor of in vivo efficacy. Compounds with a...

Osteoarthritis (OA) is a degenerative joint disease that causes pain and bone deterioration driven by an increase in prostaglandins (PGs) and inflammatory cytokines. Current treatments focus on inhibiting prostaglandin production, a pro-inflammatory lipid metabolite, with NSAID drugs; however, other lipid signaling targets could provide safer and m...

Selective optimization of side activities is a valuable source of novel lead structures in drug discovery. In this study, a com-puter-aided approach was used to de-orphanize the pleiotropic cholesterol-lowering effects of the beta-blocker talinolol, which result from the inhibition of the enzyme soluble epoxide hydrolase (sEH). X-ray structure anal...

1-(1-Propionylpiperidin-4-yl)-3-(4-(trifluoromethoxy)phenyl)urea (TPPU) is a potent soluble epoxide hydrolase (sEH) inhibitor that is used extensively in research for modulating inflammation and protecting against hypertension, neuropathic pain, and neurodegeneration. Despite its wide use in various animal disease models, the metabolism of TPPU has...

Over the last two decades polypharmacology has emerged as a new paradigm in drug discovery, even though developing drugs with high potency and selectivity toward a single biological target is still a major strategy. Often, targeting only a single enzyme or receptor shows lack of efficacy. High levels of inhibitor of a single target also can lead to...

Fatty acid amide hydrolase (FAAH) is responsible for regulating concentrations of the endocannabinoid arachidonoyl ethanolamide. Multiple FAAH inhibitors have been developed for clinical trials and have failed to demonstrate efficacy at treating pain, despite promising preclinical data. One approach toward increasing the efficacy of FAAH inhibitors...

The soluble epoxide hydrolase (sEH) is the principal regulator of epoxy fatty-acids (EpFA) transforming them in to the less active diols. Inhibitors of sEH block this activity and maintain levels of EpFA in vivo which has demonstrated potent analgesia in several preclinical models of acute and chronic pain. However, sEH inhibitors have no observabl...

Inspired by previously discovered enhanced analgesic efficacy between soluble epoxide hydrolase (sEH) and phosphodiesterase 4 (PDE4) inhibitors, we designed, synthesized and characterized 21 novel sEH/PDE4 dual inhibitors. The best of these displayed good efficacy in in vitro assays. Further pharmacokinetic studies of a subset of 4 selected compoun...

Epoxy fatty acids (EpFAs) are highly potent lipid mediators, formed by cytochrome P450 (CYP450) from polyunsaturated fatty acids. In living organisms, they will be rapidly metabolized by soluble epoxide hydrolase (sEH) to these 1,2‐diol metabolites. A still growing body of evidence suggests that the stabilization of EpFAs by inhibition of sEH has e...

Soluble epoxide hydrolase inhibitors (sEHI) stabilize biologically active lipid metabolites responsible for regulating homeostatic biological processes. Over the past 20 years, researchers at the University of California at Davis synthesized a large chemical library of potent sEHIs to elucidate the role of this enzyme in biological systems. These c...

In recent years, there has been increasing interest in designing multi‐target agents that improve efficacy and safety compared to their single target counterparts. Cyclooxygenase‐2 (COX‐2) selective inhibitors (coxibs) are effective drugs for treating inflammation, pain, and cancer. However, their mechanism‐based side effects limit their use. Meanw...

The soluble epoxide hydrolase (sEH) is the principal regulator of epoxy fatty‐acids (EpFA) transforming them in to the less active diols. Inhibitors of sEH block this activity and maintain levels of EpFA in vivo which has demonstrated potent analgesia in several preclinical models of acute and chronic pain. However, sEH inhibitors have no observabl...

Eicosanoids are biologically active lipid signaling molecules derived from polyunsaturated fatty acids. Many of the actions of eicosanoid metabolites formed by cyclooxygenase and lipoxygenase enzymes have been characterized, however, the epoxy-fatty acids (EpFAs) formed by cytochrome P450 enzymes are newly described by comparison. The EpFA metaboli...

The innate immune system of patients with Alzheimer's disease and mild cognitive impairment (MCI) is deregulated with highly increased or decreased transcription of inflammatory genes and consistently depressed phagocytosis of amyloid-β1-42 (Aβ) by monocytes and macrophages. Current immune therapies target single mechanisms in the adaptive immune s...

The soluble epoxide hydrolase (sEH) is a regulatory enzyme responsible for the metabolism of bioactive lipid epoxides of both omega-6 and omega-3 long chain polyunsaturated fatty acids. These natural epoxides mediate cell signaling in several physiological functions including blocking inflammation, high blood pressure and both inflammatory and neur...

ω-Hydroxy polyunsaturated fatty acids (PUFAs), natural metabolites from arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were prepared via convergent synthesis approach using two key steps: Cu-mediated C-C bond formation to construct methylene skipped poly-ynes and a partial alkyne hydrogenation where the presence...

Background: Neuropathic pain is a debilitating condition with no adequate therapy. The health benefits of omega-3 fatty acids are established, however, the role of docosahexaenoic acid (DHA) in limiting pain has only recently been described and the mechanisms of this action remain unknown. DHA is metabolized into epoxydocosapentanoic acids (EDPs)...

Soluble epoxide hydrolase (sEH) inhibitors function to stabilize biologically active lipid metabolites responsible for regulating homeostatic biological processes. The presence of these beneficial lipid metabolites in tissues and their metabolism by sEH into less active diols was first reported 30 years ago, and many subsequent advances were facili...

Epoxy fatty acids (EPFA) are known chemical mediators, and they are regulated by both biosynthesis and by hydrolysis to their corresponding diols by the soluble epoxide hydrolase (sEH). A new series of orally available chemicals act as transition state mimics to inhibit the sEH at low picomolar concentrations and increase circulating titers of EPFA...

The soluble epoxide hydrolase (sEH) is a master regulatory enzyme downstream in the cytochrome P450 (CYP450) branch of the arachidonic acid (ARA) cascade. The sEH enzyme is the principal route of degradation for the bioactive epoxidized metabolites of long chain fatty acids formed by CYP450 activity. The most studied of these are the epoxyeicosatri...

Significance Depression is the most common and debilitating psychiatric disorder in the world. However, the precise mechanisms underlying depression remain largely unknown. Recent evidence suggests that soluble epoxide hydrolase (sEH) plays a key role in inflammation, which is involved in depression. The sEH inhibitor, TPPU, showed antidepressant e...

Neuropathic pain is currently an insufficiently treated clinical condition. There remains a Scritical need for efficacious therapies without severe side effects to treat the uniquely persistent and tonic pain of neuropathy. Inhibitors of the soluble epoxide hydrolase (sEH) enzyme which stabilize endogenous epoxy fatty acids have demonstrated antihy...

Diabetes is affecting the life of millions of people. A large proportion of diabetic patients suffer from severe complications such as neuropathic pain and current treatments for these complications have deleterious side effects. Thus, alternate therapeutic strategies are needed. Recently, the elevation of epoxy-fatty acids through inhibition of so...

Neuropathic pain remains an unmet clinical need. In addition to nerve injury cases of neuropathy diabetes is increasing worldwide and diabetic neuropathy, the most frequent secondary condition to diabetes, will increase with it. Recent investigations reveal lipids as signaling mediators and their functional significance in nociception is receiving...

In the brain, seizures lead to release of large amounts of polyunsaturated fatty acids including arachidonic acid (ARA). ARA is a substrate for three major enzymatic routes of metabolism by cyclooxygenase, lipoxygenase and cytochrome P450 enzymes. These enzymes convert ARA to potent lipid mediators including prostanoids, leukotrienes and epoxyeicos...

Arachidonic acid (ARA) undergoes enzyme-mediated oxidative metabolism, resulting in the formation of a number of biologically active metabolites. For over a century, these biochemical transformations have been the target of numerous pharmacological drugs for inflammation and pain. In particular, non-steroidal anti-inflammatory drugs (NSAIDs) and cy...

Provided are methods for treating, reducing, alleviating, and/or inhibiting neuropathic pain by orally, i.v. or intrathecally administering an effective amt. of an inhibitor of sol. epoxide hydrolase ("sEH"), to a patient in need thereof. In another embodiment of the invention the sol. epoxide hydrolase (sEH) inhibitor of the invention include e.g....

Epoxy-fatty acids have been recognized as important cell signaling molecules with multiple biological effects including anti-nociception. The main degradation pathway of these signaling molecules is via the soluble epoxide hydrolase (sEH) enzyme. Inhibitors of sEH extend the anti-nociceptive effects of fatty acid epoxides. In this study two models...

The nerve damage occurring as a consequence of glucose toxicity in diabetes leads to neuropathic pain, among other problems. This pain dramatically reduces the quality of life in afflicted patients. The progressive damage to the peripheral nervous system is irreversible although strict control of hyperglycemia may prevent further damage. Current tr...

Soluble epoxide hydrolase (sEH, EC 3.3.2.10 ) is responsible for metabolism of endogeneously derived fatty acid oxiranes, epoxyeicosatrienoic acids (EETs) to the corresponding diols, dihydroxyepoxyeicosatrienoic acids (DHETs). EETs are the products of arachidonic acid by cytochromes P450 epoxygenases and are key modulators involved in inflammation,...

The soluble epoxide hydrolase (sEH) enzyme regulates the levels of endogenous epoxygenated fatty acid (EFA) lipid metabolites by rapidly degrading these molecules. The EFAs have pleiotropic biological activities including the modulation of nociceptive signaling. Recent findings indicate that the EFAs, in particular the arachidonic acid (AA) derived...

Pain is a major health concern even though numerous analgesic agents are available. Side effects and lack of wide-spectrum efficacy of current drugs justify efforts to better understand pain mechanisms. Stabilization of natural epoxy-fatty acids (EFAs) through inhibition of the soluble epoxide hydrolase (sEH) reduces pain. However, in the absence o...

A series of dual inhibitors containing a 1,5-diarylpyrazole and a urea were designed, synthesized, and evaluated as novel COX-2/sEH dual inhibitors in vitro using recombinant enzyme assays and in vivo using a lipopolysaccharide (LPS) induced model of pain in rats. The best inhibition potencies and selectivity for sEH and COX-2 over COX-1 were obtai...

High-throughput analyses of a large number of samples for pharmacokinetic (PK) studies are essential in drug development. Analysis of drug candidates from blood using LC-ESI-MS generally requires separation of the plasma fraction followed by various offline sample preparation procedures. This step is a bottleneck that impedes throughput. In order t...

The soluble epoxide hydrolase (sEH) enzyme was discovered while investigating the metabolism of xenobiotic compounds in the Casida laboratory. However, an endogenous role of sEH is to regulate the levels of a group of potent bioactive lipids, epoxygenated fatty acids (EFAs), that have pleiotropic biological activities. The EFAs, in particular the a...

During inflammation, a large amount of arachidonic acid (AA) is released into the cellular milieu and cyclooxygenase enzymes convert this AA to prostaglandins that in turn sensitize pain pathways. However, AA is also converted to natural epoxyeicosatrienoic acids (EETs) by cytochrome P450 enzymes. EET levels are typically regulated by soluble epoxi...