Cytochrome P450 epoxygenase pathway of polyunsaturated fatty acid metabolism

Expedited access to polyunsaturated fatty acids and biofunctional analogues by full solid-phase synthesis

Polyunsaturated fatty acids (PUFAs) represent a fundamental and essential class of lipids that exhibit versatile biofunctions. Lipidomic analysis has identified a growing number of lipid species, including PUFAs with diverse structural variations and biofunctions, yet their structure-function relationships are still largely unknown. In this context, an efficient synthesis of PUFAs would be highly desirable. However, no practical methodology exists for their preparation, in contrast to peptides and nucleic acids, for which diverse molecules are accessible through a well-established solid-phase synthesis. To address this, we have developed an efficient and expedited method to access a wide array of PUFAs by full solid-phase synthesis. The method allows the synthesis of various PUFAs and analogues through rapid and facile operations. Moreover, within our PUFA library, we have discovered an artificial fatty acid, antiefin, that has a high anti-inflammatory effect in vivo. Therefore, our practical synthetic pathway to PUFAs, a crucial class of lipids, is expected to make an important contribution to lipid science.

Survival of the Littlest: Navigating Sepsis Diagnosis beyond Inflammation in Preterm Neonates

Sepsis diagnosis in preterm neonates is challenging due to symptom overlap with non-infectious inflammatory conditions, and slow, unreliable diagnostic practices. This case-control study aims to elucidate sepsis pathophysiology, and identify metabolic biomarkers for timely, accurate diagnosis, to prevent rapid health deterioration and unnecessary antibiotic use. Liquid chromatography-mass spectrometry was performed on 227 plasma samples, obtained from 94 preterm neonates, to measure 317 metabolites encompassing amines and signaling lipids. Linear mixed-effect modeling, LASSO and logistic regression models were calculated to assess metabolic alterations across control, systemic inflammation-no sepsis (SINS), and sepsis groups. Stratification by sex and pathogen type allowed identification of sex-specific responses and pathogen-driven variations in sepsis. Key findings include (i) shared metabolic changes in SINS and sepsis, (ii) progressive alterations from control to SINS to sepsis, and (iii) sepsis-specific markers. Males exhibited a pro-inflammatory phenotype while females showed an anti-inflammatory phenotype in response to sepsis. Gram-positive and gram-negative bacterial sepsis revealed distinct metabolic profiles. A diagnostic model comprising 5 metabolic features and IL-6 distinguished SINS from sepsis at clinical suspicion (AUC 0.79, sensitivity 0.85, specificity 0.82). These insights highlight the potential of metabolomics to revolutionize neonatal sepsis management with precision diagnostics and personalized treatment strategies.

The Hunt for the Putative Epoxyeicosatrienoic Acid Receptor

Epoxyeicosatrienoic acids, or EETs, are signaling molecules formed by the metabolism of arachidonic acid by cytochrome P450 enzymes. They are well-known for their anti-inflammatory effects, their ability to lower blood pressure, and benefits to cardiovascular outcomes. Despite the wealth of data demonstrating their physiological benefits, the putative high-affinity receptor that mediates these effects is yet to be identified. The recent report that the sphingosine-1-phosphate receptor 1 (S1PR1) is a high-affinity receptor for a related epoxy lipid prompted us to ask, "Why has the putative EET receptor not been discovered yet? What information about the discoveries of lipid epoxide receptors can help us identify the putative EET receptor?" In this review, we summarize the evidence supporting that the putative EET receptor exists. We then review the data showing EETs binding to other, low-affinity receptors and the discovery of receptors for similar lipid metabolites that can serve as a model for identifying the putative EET receptor. We hope this review will revitalize the search for this important receptor, which can facilitate the development of anti-inflammatory and cardiovascular therapeutics.

In Silico and In Vitro Analyses of Strawberry-Derived Extracts in Relation to Key Compounds' Metabolic and Anti-Tumor Effects

Plant extracts contain many small molecules that are less investigated. The present paper aims to study in silico physical-chemical, pharmacokinetic, medicinal chemistry and lead/drug-likeness properties and the ability to interfere with the activity of P-glycoprotein (P-gp) transporter and cytochrome P450 (CYP) oxidase system in humans of phloridzin, phloretin, 4-methylchalcone metabolic series alongside the top three compounds found in the ethanolic extract from strawberries (S), namely 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 2-pyrrolidinone 5-(cyclohexylmethyl) and hexadecanoic acid. The phloridzin derivatives also were studied for their inhibitory potential upon Bcl-2, TNKS1 and COX-2 molecular targets. In vitro, Caco-2 studies analyzed the cytoprotective and anti-proliferative activity of S and the three phloridzin derivatives (pure compounds) in comparison with their combination 1:1 (GAE/pure compound, w/w), in the range 1 to 50 µg active compounds per test sample. Altogether, it was concluded that phloretin (Phl) can be used alone or in combination with S to support intestinal cell health in humans. Phloridzin (Phd) and phloridzin combined with S were proven ineffective. 4-methylchalcone (4-MeCh) combined with S indicated no advantages, while the pure compound exhibited augmented inhibitory effects, becoming a candidate for combinations with anticancer drugs. Overall, in silico studies revealed possible limitations in the practical use of phloridzin derivatives due to their potential to interfere with the activity of several major CYP enzymes.

Effects of 17,18-Epoxyeicosatetraenoic Acid and 19,20-Epoxydocosapentaenoic Acid Combined with Soluble Epoxide Hydrolase Inhibitor t-TUCB on Brown Adipogenesis and Mitochondrial Respiration

Background/Objectives: 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP) are bioactive metabolites produced from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively, by CYP450s. These metabolites are unstable and quickly metabolized by auto-oxidation, esterification, β-oxidation, or hydrolysis by soluble epoxide hydrolase (sEH). 17,18-EEQ or 19,20-EDP combined with a potent sEH inhibitor t-TUCB differentially activated brown adipose tissue in diet-induced obesity. In the current study, we investigated whether these n-3 epoxy fatty acids with t-TUCB directly promote brown adipocyte differentiation and their thermogenic capacities. Methods: Murine brown preadipocytes were treated with 17,18-EEQ or 19,20-EDP with t-TUCB during and post differentiation. Brown marker protein expression and mitochondrial respiration were measured. In addition, the activation of PPARγ and suppression of NFκB reporter by 17,18-EEQ or 19,20-EDP alone or with t-TUCB were assessed, and the roles of PPARγ were evaluated with PPARγ knockdown and GW9662. Results: 17,18-EEQ or 19,20-EDP with t-TUCB promoted brown adipogenesis and mitochondrial respiration and uncoupling. Moreover, with t-TUCB, both epoxides improved mitochondrial respiration, but only 17,18-EEQ with t-TUCB significantly increased mitochondrial uncoupling (and heat production) in the differentiated adipocytes. PPARγ may be required for the effects of epoxides on differentiation but not on the thermogenic function post differentiation. Conclusions: The results demonstrate that, with t-TUCB, 17,18-EEQ and 19,20-EDP promote brown adipogenesis and mitochondrial respiration and uncoupling. 17,18-EEQ also promotes thermogenesis in differentiated brown adipocytes. Together, the results suggest thermogenic potentials of tested n-3 epoxides, especially 17,18-EEQ with t-TUCB. Translational studies of these n-3 epoxides on human brown adipocyte differentiation and functions are warranted.

Methylated cell-free DNA as a novel biomarker in Alzheimer's disease

Due to an aging population, Alzheimer's disease (AD), a neurodegenerative disorder, has affected more than 40 million people worldwide, a figure predicted to significantly increase in the coming decades. Despite much effort to understand AD pathogenesis, effective diagnosis and treatment remain a challenge. However, the development of liquid biopsy including the analysis of cell-free DNA (cfDNA) and methylation thereof has provided an alternative source of investigation to further explore the pathophysiology of AD. Herein, we discuss the research progress to date and highlight clinical applications of methylated cfDNA in AD.

Fatty acid binding protein as a new age biomarker

Small lipid-binding proteins known as fatty acid-binding proteins (FABPs) are extensively expressed in cells having elevated levels of fatty acid (FA) metabolism. There are ten known FABPs in mammals that exhibit expression patterns specific to tissues and tertiary structures that are substantially preserved. FABPs were first investigated as FA transport proteins inside cells. Subsequent research has shown that they are involved in signalling within their expression cells and in metabolism of lipid, directly and through the control of expression of gene. Additionally, there is evidence that they might be released and influence circulatory function. It has been observed that some tissues and organs linked to inflammatory, metabolic illnesses and also infectious disease have markedly elevated expression levels of FABPs. Thus, in addition to previously identified markers, FABPs represent a promising new biomarker that require additional investigation to optimise illness detection and prognosis techniques.

Discovery of glycosidated glycyrrhetinic acid derivatives: Natural product-based soluble epoxide hydrolase inhibitors

There are few reports on soluble epoxide hydrolase (sEH) structure-activity relationship studies using natural product-based scaffolds. In this study, we discovered that C-30 urea derivatives of glycyrrhetinic acid such as 33, rather than C-20/C-3 urea derivatives, possess in vitro sEH inhibitory capabilities. Furthermore, we explored the impact of stereoconfigurations at C-3 and C-18 positions, and glycosidic bonds at the 3-OH on the compound's activity. Consequently, a glycoside of 33, specifically 49Cα containing alpha-oriented mannose, exhibited promising in vivo efficacy in alleviating carrageenan-induced paw edema and acetic acid-induced writhing. Meanwhile, 49Cα demonstrated potential in mitigating acute pancreatitis by modulating the ratios of anti-inflammatory epoxyeicosatrienoic acids (EETs) to pro-inflammatory dihydroxyeicosatrienoic acids (DHETs). The co-crystal structure of sEH in complex with 49Cα revealed that the N-tetrahydropyranylmethylene urea hydrogen bonded with the residues within the sEH tunnel, contrasting with the mannose component that extended beyond the tunnel's confines. Our findings highlight 49Cα (coded LQ-38) as a promising candidate for anti-inflammatory and analgesic effects, and pave the way for the future rational design of triterpenoid-based sEH inhibitors.

Mice deficient in the phosphatase activity of sEH show decreased levels of the endocannabinoid 2-AG in the olfactory bulb and depressive-like behavior

Soluble epoxide hydrolase (sEH) is a bifunctional enzyme that has epoxide hydrolase activity and phosphatase activity. Our earlier study revealed that lysophosphatidic acids are a substrate of the phosphatase activity of sEH in vitro, but its physiological function remained unknown. Herein, we used the CRISPR/Cas9 system and i-GONAD method to generate mice that are deficient in sEH phosphatase activity. In the mouse brain, sEH was highly expressed in the olfactory bulb. Deletion of the sEH phosphatase activity resulted in decreased levels of the endocannabinoid 2-arachidonoyl glycerol (2-AG), which is a dephosphorylated form of 2-arachidonoyl-lysophosphatidic acid in the olfactory bulb. The sEH-deficient mice showed depressive-like behavior. These results indicate that sEH can regulate the production of 2-AG and brain function in vivo.

Phospholipids, Sphingolipids, and Cholesterol-Derived Lipid Mediators and Their Role in Neurological Disorders

Neural membranes are composed of phospholipids, sphingolipids, cholesterol, and proteins. In response to cell stimulation or injury, the metabolism of lipids generates various lipid mediators, which perform many cellular functions. Thus, phospholipids release arachidonic acid or docosahexaenoic acid from the sn-2 position of the glycerol moiety by the action of phospholipases A2. Arachidonic acid is a precursor for prostaglandins, leukotrienes, thromboxane, and lipoxins. Among these mediators, prostaglandins, leukotrienes, and thromboxane produce neuroinflammation. In contrast, lipoxins produce anti-inflammatory and pro-resolving effects. Prostaglandins, leukotrienes, and thromboxane are also involved in cell proliferation, differentiation, blood clotting, and blood vessel permeability. In contrast, DHA-derived lipid mediators are called specialized pro-resolving lipid metabolites (SPMs). They include resolvins, protectins, and maresins. These mediators regulate immune function by producing anti-inflammatory, pro-resolving, and cell protective effects. Sphingolipid-derived metabolites are ceramide, ceramide1-phosphate, sphingosine, and sphingosine 1 phosphate. They regulate many cellular processes, including enzyme activities, cell migration and adhesion, inflammation, and immunity. Cholesterol is metabolized into hydroxycholesterols and 7-ketocholesterol, which not only disrupts membrane fluidity, but also promotes inflammation, oxidative stress, and apoptosis. These processes lead to cellular damage.

Targeting the soluble epoxide hydrolase pathway as a novel therapeutic approach for the treatment of pain

Chronic pain is a major burden and the complexities of chronic pain pathophysiology, including both peripheral and central sensitisation mechanisms, involves multiple cell types (neuronal, immune, neuroimmune, and vascular) which substantially complicates the development of new effective analgesic treatments. The epoxy fatty acids (EpFAs), including the epoxyeicosatrienoic acids (EETs), are derived from the metabolism of polyunsaturated fatty acids (PUFAs) via the cytochrome P450 enzymatic pathway and act to shut-down inflammatory signalling and provide analgesia. The EpFAs are rapidly metabolised by the enzyme soluble epoxide hydrolase (sEH) into their corresponding diol metabolites, which recent studies suggest are pro-inflammatory and pro-nociceptive. This review discusses clinical and mechanistic evidence for targeting the sEH pathway for the treatment of pain.

Cytochrome P450-soluble epoxide hydrolase oxylipins, depression and cognition in type 2 diabetes

AIMS

This study examined serum cytochrome P450-soluble epoxide hydrolase (CYP450-sEH) oxylipins and depressive symptoms together in relation to cognitive performance in individuals with type 2 diabetes mellitus (T2DM).

METHODS

Clinically cognitively normal T2DM individuals were recruited (NCT04455867). Depressive symptom severity was assessed using the Beck Depression Inventory-II (BDI-II; total scores ≤13 indicated minimal depressive symptoms and ≥ 14 indicated significant depressive symptoms). Executive function and verbal memory were assessed. Fasting serum oxylipins were quantified by ultra-high-performance liquid chromatography tandem mass-spectrometry.

RESULTS

The study included 85 participants with minimal depressive symptoms and 27 with significant symptoms (mean age: 63.3 ± 9.8 years, 49 % women). In all participants, higher concentrations of linoleic acid derived sEH (12,13-dihydroxyoctadecamonoenoic acid; DiHOME) and CYP450 (12(13)-epoxyoctadecamonoenoic acid; EpOME) metabolites were associated with poorer executive function (F1,101 = 6.094, p = 0.015 and F1,101 = 5.598, p = 0.020, respectively). Concentrations of multiple sEH substrates interacted with depressive symptoms to predict 1) poorer executive function, including 9(10)-EpOME (F1,100 = 12.137, p < 0.001), 5(6)-epoxyeicosatrienoic acid (5(6)-EpETrE; F1,100 = 6.481, p = 0.012) and 11(12)-EpETrE (F1,100 = 4.409, p = 0.038), and 2) verbal memory, including 9(10)-EpOME (F1,100 = 4.286, p = 0.041), 5(6)-EpETrE (F1,100 = 6.845, p = 0.010), 11(12)-EpETrE (F1,100 = 3.981, p = 0.049) and 14(15)-EpETrE (F1,100 = 5.019, p = 0.027).

CONCLUSIONS

Associations of CYP450-sEH metabolites and depressive symptoms with cognition highlight the biomarker and therapeutic potential of the CYP450-sEH pathway in T2DM.

Triazine herbicide prometryn alters epoxide hydrolase activity and increases cytochrome P450 metabolites in murine livers via lipidomic profiling

Oxylipins are a group of bioactive fatty acid metabolites generated via enzymatic oxygenation. They are notably involved in inflammation, pain, vascular tone, hemostasis, thrombosis, immunity, and coagulation. Oxylipins have become the focus of therapeutic intervention since they are implicated in many conditions, such as nonalcoholic fatty liver disease, cardiovascular disease, and aging. The liver plays a crucial role in lipid metabolism and distribution throughout the organism. Long-term exposure to pesticides is suspected to contribute to hepatic carcinogenesis via notable disruption of lipid metabolism. Prometryn is a methylthio-s-triazine herbicide used to control the growth of annual broadleaf and grass weeds in many cultivated plants. The amounts of prometryn documented in the environment, mainly waters, soil and plants used for human and domestic consumption are significantly high. Previous research revealed that prometryn decreased liver development during zebrafish embryogenesis. To understand the mechanisms by which prometryn could induce hepatotoxicity, the effect of prometryn (185 mg/kg every 48 h for seven days) was investigated on hepatic and plasma oxylipin levels in mice. Using an unbiased LC-MS/MS-based lipidomics approach, prometryn was found to alter oxylipins metabolites that are mainly derived from cytochrome P450 (CYP) and lipoxygenase (LOX) in both mice liver and plasma. Lipidomic analysis revealed that the hepatotoxic effects of prometryn are associated with increased epoxide hydrolase (EH) products, increased sEH and mEH enzymatic activities, and induction of oxidative stress. Furthermore, 9-HODE and 13-HODE levels were significantly increased in prometryn treated mice liver, suggesting increased levels of oxidation products. Together, these results support that sEH may be an important component of pesticide-induced liver toxicity.

Membrane Epilipidome-Lipid Modifications, Their Dynamics, and Functional Significance

Lipids are characterized by extremely high structural diversity translated into a wide range of physicochemical properties. As such, lipids are vital for many different functions including organization of cellular and organelle membranes, control of cellular and organismal energy metabolism, as well as mediating multiple signaling pathways. To maintain the lipid chemical diversity and to achieve rapid lipid remodeling required for the responsiveness and adaptability of cellular membranes, living systems make use of a network of chemical modifications of already existing lipids that complement the rather slow biosynthetic pathways. Similarly to biopolymers, which can be modified epigenetically and posttranscriptionally (for nucleic acids) or posttranslationally (for proteins), lipids can also undergo chemical alterations through oxygenation, nitration, phosphorylation, glycosylation, etc. In this way, an expanded collective of modified lipids that we term the "epilipidome," provides the ultimate level of complexity to biological membranes and delivers a battery of active small-molecule compounds for numerous regulatory processes. As many lipid modifications are tightly controlled and often occur in response to extra- and intracellular stimuli at defined locations, the emergence of the epilipidome greatly contributes to the spatial and temporal compartmentalization of diverse cellular processes. Accordingly, epilipid modifications are observed in all living organisms and are among the most consistent prerequisites for complex life.

Emerging Roles and Therapeutic Applications of Arachidonic Acid Pathways in Cardiometabolic Diseases

Cardiometabolic disease has become a major health burden worldwide, with sharply increasing prevalence but highly limited therapeutic interventions. Emerging evidence has revealed that arachidonic acid derivatives and pathway factors link metabolic disorders to cardiovascular risks and intimately participate in the progression and severity of cardiometabolic diseases. In this review, we systemically summarized and updated the biological functions of arachidonic acid pathways in cardiometabolic diseases, mainly focusing on heart failure, hypertension, atherosclerosis, nonalcoholic fatty liver disease, obesity, and diabetes. We further discussed the cellular and molecular mechanisms of arachidonic acid pathway-mediated regulation of cardiometabolic diseases and highlighted the emerging clinical advances to improve these pathological conditions by targeting arachidonic acid metabolites and pathway factors.

Cardioprotective properties of OMT-28, a synthetic analog of omega-3 epoxyeicosanoids

OMT-28 is a metabolically robust small molecule developed to mimic the structure and function of omega-3 epoxyeicosanoids. However, it remained unknown to what extent OMT-28 also shares the cardioprotective and anti-inflammatory properties of its natural counterparts. To address this question, we analyzed the ability of OMT-28 to ameliorate hypoxia/reoxygenation (HR)-injury and lipopolysaccharide (LPS)-induced endotoxemia in cultured cardiomyocytes. Moreover, we investigated the potential of OMT-28 to limit functional damage and inflammasome activation in isolated perfused mouse hearts subjected to ischemia/reperfusion (IR) injury. In the HR model, OMT-28 (1 μM) treatment largely preserved cell viability (about 75 versus 40% with the vehicle) and mitochondrial function as indicated by the maintenance of NAD+/NADH-, ADP/ATP-, and respiratory control ratios. Moreover, OMT-28 blocked the HR-induced production of mitochondrial reactive oxygen species. Pharmacological inhibition experiments suggested that Gαi, PI3K, PPARα, and Sirt1 are essential components of the OMT-28-mediated pro-survival pathway. Counteracting inflammatory injury of cardiomyocytes, OMT-28 (1 μM) reduced LPS-induced increases in TNFα protein (by about 85% versus vehicle) and NF-κB DNA binding (by about 70% versus vehicle). In the ex vivo model, OMT-28 improved post-IR myocardial function recovery to reach about 40% of the baseline value compared to less than 20% with the vehicle. Furthermore, OMT-28 (1 μM) limited IR-induced NLRP3 inflammasome activation similarly to a direct NLRP3 inhibitor (MCC950). Overall, this study demonstrates that OMT-28 possesses potent cardio-protective and anti-inflammatory properties supporting the hypothesis that extending the bioavailability of omega-3 epoxyeicosanoids may improve their prospects as therapeutic agents.

Novel molecular mechanism driving neuroprotection after soluble epoxide hydrolase inhibition: Insights for Alzheimer's disease therapeutics

BACKGROUND

Neuroinflammation is widely recognized as a significant hallmark of Alzheimer's disease (AD). To combat neuroinflammation, the inhibition of the soluble epoxide hydrolase (sEH) enzyme has been demonstrated crucial. Importantly, sEH inhibition could be related to other neuroprotective pathways described in AD.

AIMS

The aim of the study was to unveil new molecular pathways driving neuroprotection through sEH, we used an optimized, potent, and selective sEH inhibitor (sEHi, UB-SCG-51).

MATERIALS AND METHODS

UB-SCG-51 was tested in neuroblastoma cell line, SH-SY5Y, in primary mouse and human astrocytes cultures challenged with proinflammatory insults and in microglia cultures treated with amyloid oligomers, as well as in mice AD model (5XFAD).

RESULTS

UB-SCG-51 (10 and 30 μM) prevented neurotoxic reactive-astrocyte conversion in primary mouse astrocytes challenged with TNF-α, IL-1α, and C1q (T/I/C) combination for 24 h. Moreover, in microglial cultures, sEHi reduced inflammation and glial activity. In addition, UB-SCG-51 rescued 5XFAD cognitive impairment, reducing the number of Amyloid-β plaques and Tau hyperphosphorylation accompanied by a reduction in neuroinflammation and apoptotic markers. Notably, a transcriptional profile analysis revealed a new pathway modulated by sEHi treatment. Specifically, the eIF2α/CHOP pathway, which promoted the endoplasmic reticulum response, was increased in the 5XFAD-treated group. These findings were confirmed in human primary astrocytes by combining sEHi and eIF2α inhibitor (eIF2αi) treatment. Besides, combining both treatments resulted in increased in C3 gene expression after T/I/C compared with the group treated with sEHi alone in cultures.

DISCUSSION

Therefore, sEHi rescued cognitive impairment and neurodegeneration in AD mice model, based on the reduction of inflammation and eIF2α/CHOP signaling pathway.

CONCLUSIONS

In whole, our results support the concept that targeting neuroinflammation through sEH inhibition is a promising therapeutic strategy to fight against Alzheimer's disease with additive and/or synergistic activities targeting neuroinflammation and cell stress.

Oxylipins biosynthesis and the regulation of bovine postpartum inflammation

Uncontrolled or dysregulated inflammation has adverse effects on the reproduction, production and health of animals, and is a major pathological cause of increased incidence and severity of infectious and metabolic diseases. To achieve successful transition from a non-lactation pregnant state to a non-pregnant lactation state, drastic metabolic and endocrine alteration have taken place in dairy cows during the periparturient period. These physiological changes, coupled with decreased dry matter intake near calving and sudden change of diet composition after calving, have the potential to disrupt the delicate balance between pro- and anti-inflammation, resulting in a disordered or excessive inflammatory response. In addition to cytokines and other immunoregulatory factors, most oxylipins formed from polyunsaturated fatty acids (PUFAs) via enzymatic and nonenzymatic oxygenation pathways have pro- or anti-inflammatory properties and play a pivotal role in the onset, development and resolution of inflammation. However, little attention has been paid to the possibility that oxylipins could function as endogenous immunomodulating agents. This review will provide a detailed overview of the main oxylipins derived from different PUFAs and discuss the regulatory role that oxylipins play in the postpartum inflammatory response in dairy cows. Based on the current research, much remains to be illuminated in this emerging field. Understanding the role that oxylipins play in the control of postpartum inflammation and inflammatory-based disease may improve our ability to prevent transition disorders via Management, pharmacological, genetic selection and dietary intervention strategies.

Attenuation of Polycyclic Aromatic Hydrocarbon (PAH)-Induced Carcinogenesis and Tumorigenesis by Omega-3 Fatty Acids in Mice In Vivo

Lung cancer is the leading cause of cancer death worldwide. Polycyclic aromatic hydrocarbons (PAHs) are metabolized by the cytochrome P450 (CYP)1A and 1B1 to DNA-reactive metabolites, which could lead to mutations in critical genes, eventually resulting in cancer. Omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are beneficial against cancers. In this investigation, we elucidated the mechanisms by which omega-3 fatty acids EPA and DHA will attenuate PAH-DNA adducts and lung carcinogenesis and tumorigenesis mediated by the PAHs BP and MC. Adult wild-type (WT) (A/J) mice, Cyp1a1-null, Cyp1a2-null, or Cyp1b1-null mice were exposed to PAHs benzo[a]pyrene (BP) or 3-methylcholanthrene (MC), and the effects of omega-3 fatty acid on PAH-mediated lung carcinogenesis and tumorigenesis were studied. The major findings were as follows: (i) omega-3 fatty acids significantly decreased PAH-DNA adducts in the lungs of each of the genotypes studied; (ii) decreases in PAH-DNA adduct levels by EPA/DHA was in part due to inhibition of CYP1B1; (iii) inhibition of soluble epoxide hydrolase (sEH) enhanced the EPA/DHA-mediated prevention of pulmonary carcinogenesis; and (iv) EPA/DHA attenuated PAH-mediated carcinogenesis in part by epigenetic mechanisms. Taken together, our results suggest that omega-3 fatty acids have the potential to be developed as cancer chemo-preventive agents in people.

In ovo delivery of oregano essential oil activated xenobiotic detoxification and lipid metabolism at hatch in broiler chickens

In ovo interventions are used to improve embryonic development and robustness of chicks. The objective of this study was to identify the optimal dose for in ovo delivery of oregano essential oil (OEO), and to investigate metabolic impacts. Broiler chickens Ross 308 fertile eggs were injected with 7 levels of OEO (0, 5, 10, 20, 30, 40, and 50 µL) into the amniotic fluid at embryonic d 17.5 (E17.5) (n = 48). Chick quality was measured by navel score (P < 0.05) and/or hatchability rates (P < 0.01) were significantly decreased at doses at or above 10 or 20 µL/egg, respectively, indicating potential toxicity. However, no effects were observed at the 5 µL/egg, suggesting that compensatory mechanisms were effective to maintain homeostasis in the developing embryo. To pursue a better understanding of these mechanisms, transcriptomic analyses of the jejunum were performed comparing the control injected with saline and the group injected with 5 µL of OEO. The transcriptomic analyses identified that 167 genes were upregulated and 90 were downregulated in the 5 µL OEO compared to the control group injected with saline (P < 0.01). Functional analyses of the differentially expressed genes (DEG) showed that metabolic pathways related to the epoxygenase cytochrome P450 pathway associated with xenobiotic catabolic processes were significantly upregulated (P < 0.05). In addition, long-chain fatty acid metabolism associated with ATP binding transporters was also upregulated in the OEO treated group (P < 0.05). The results indicated that low doses of OEO in ovo have the potential to increase lipid metabolism in late stages (E17.5) of embryonic development. In conclusion, in ovo delivery of 5 µL OEO did not show any negative impact on hatchability and chick quality. OEO elevated expression of key enzymes and receptors involved in detoxification pathways and lipid metabolism in the jejunum of hatchling broiler chicks.

Low beauvericin concentrations promote PC-12 cell survival under oxidative stress by regulating lipid metabolism and PI3K/AKT/mTOR signaling

Beauvericin (BEA), a naturally occurring cyclic peptide with good pharmacological activity, has been widely explored in anticancer research. Although BEA is toxic, studies have demonstrated its antioxidant activity. However, to date, the antioxidant mechanisms of BEA remain unclear. Herein, we conducted a comprehensive and detailed study of the antioxidant mechanism of BEA using an untargeted metabolomics approach, subsequently validating the results. BEA concentrations of 0.5 and 1 μM significantly inhibited H2O2-induced oxidative stress (OS), decreased reactive oxygen species levels in PC-12 cells, and restored the mitochondrial membrane potential. Untargeted metabolomics indicated that BEA was primarily involved in lipid-related metabolism, suggesting its role in resisting OS in PC-12 cells by participating in lipid metabolism. BEA combated OS damage by increasing phosphatidylcholine, phosphatidylethanolamine, and sphingolipid levels. In the current study, BEA upregulated proteins related to the PI3K/AKT/mTOR pathway, thereby promoting cell survival. These findings support the antioxidant activity of BEA at low concentrations, warranting further research into its pharmacological effects.

Impact of Reperfusion on Plasma Oxylipins in ST-Segment Elevation Myocardial Infarction

ST-segment elevation myocardial infarction (STEMI) occurs as a result of acute occlusion of the coronary artery. Despite successful reperfusion using primary percutaneous coronary intervention (PPCI), a large percentage of myocardial cells die after reperfusion, which is recognized as ischemia/reperfusion injury (I/R). There are rapid changes in plasma lipidome during myocardial reperfusion injury. However, the impact of coronary artery reperfusion on plasma oxylipins is unknown. This study aimed to investigate alterations in the oxylipin profiles of STEMI patients during ischemia and at various reperfusion time points following PPCI. Blood samples were collected from patients presenting with STEMI prior to PPCI (Isch, n = 45) and subsequently 2 h following successful reperfusion by PPCI (R-2 h, n = 42), after 24 h (R-24 h, n = 44), after 48 h (R-48 h, n = 43), and then 30 days post PPCI (R-30 d, n = 29). As controls, blood samples were collected from age- and sex-matched patients with non-obstructive coronary artery disease after diagnostic coronary angiography. High-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) using deuterated standards was used to identify and quantify oxylipins. In patients presenting with STEMI prior to reperfusion (Isch group), the levels of docosahexaenoic acid (DHA)-derived oxylipins were significantly higher when compared with controls. Their levels were also significantly correlated with the peak levels of creatine kinase (CK) and troponin T(TnT) before reperfusion (CK: r = 0.33, p = 0.046, TnT: r = 0.50, p = 1.00 × 10-3). The total concentrations of oxylipins directly produced by 5-lipoxygenase (5-LOX) were also significantly elevated in the Isch group compared with controls. The ratio of epoxides (generated through epoxygenase) to diols (generated by soluble epoxide hydrolysis (sEH)) was significantly lower in the Isch group compared with the controls. Following reperfusion, there was an overall reduction in plasma oxylipins in STEMI patients starting at 24 h post PPCI until 30 days. Univariate receiver operating characteristic (ROC) curve analysis also showed that an elevated ratio of epoxides to diols during ischemia is a predictor of smaller infarct size in patients with STEMI. This study revealed a large alteration in plasma oxylipins in patients presenting with STEMI when compared with controls. Total oxylipin levels rapidly reduced post reperfusion with stable levels reached 24 h post reperfusion and maintained for up to 30 days post infarct. Given the shifts in plasma oxylipins following coronary artery reperfusion, further research is needed to delineate their clinical impact in STEMI patients.

The metabolic benefits of substituting sucrose for maple syrup are associated with a shift in carbohydrate digestion and gut microbiota composition in high-fat high-sucrose diet-fed mice

Overconsumption of added sugars is now largely recognized as a major culprit in the global situation of obesity and metabolic disorders. Previous animal studies reported that maple syrup (MS) is less deleterious than refined sugars on glucose metabolism and hepatic health, but the mechanisms remain poorly studied. Beyond its content in sucrose, MS is a natural sweetener containing several bioactive compounds, such as polyphenols and inulin, which are potential gut microbiota modifiers. We aimed to investigate the impact of MS on metabolic health and gut microbiota in male C57Bl/6J mice fed a high-fat high-sucrose (HFHS + S) diet or an isocaloric HFHS diet in which a fraction (10% of the total caloric intake) of the sucrose was substituted by MS (HFHS + MS). Insulin and glucose tolerance tests were performed at 5 and 7 wk into the diet, respectively. The fecal microbiota was analyzed by whole-genome shotgun sequencing. Liver lipids and inflammation were determined, and hepatic gene expression was assessed by transcriptomic analysis. Maple syrup was less deleterious on insulin resistance and decreased liver steatosis compared with mice consuming sucrose. This could be explained by the decreased intestinal α-glucosidase activity, which is involved in carbohydrate digestion and absorption. Metagenomic shotgun sequencing analysis revealed that MS intake increased the abundance of Faecalibaculum rodentium, Romboutsia ilealis, and Lactobacillus johnsonii, which all possess gene clusters involved in carbohydrate metabolism, such as sucrose utilization and butyric acid production. Liver transcriptomic analyses revealed that the cytochrome P450 (Cyp450) epoxygenase pathway was differently modulated between HFHS + S- and HFHS + MS-fed mice. These results show that substituting sucrose for MS alleviated dysmetabolism in diet-induced obese mice, which were associated with decreased carbohydrate digestion and shifting gut microbiota.NEW & NOTEWORTHY The natural sweetener maple syrup has sparked much interest as an alternative to refined sugars. This study aimed to investigate whether the metabolic benefits of substituting sucrose with an equivalent dose of maple syrup could be linked to changes in gut microbiota composition and digestion of carbohydrates in obese mice. We demonstrated that maple syrup is less detrimental than sucrose on metabolic health and possesses a prebiotic-like activity through novel gut microbiota and liver mechanisms.

Dose-response effect of Montelukast on post-extraction dental socket repair and skeletal phenotype of mice

Bone metabolism and repair are directly regulated by arachidonic acid metabolites. At present, we analyzed the dose-response effects of a selective cysteinyl leukotriene receptor type-1 antagonist during bone repair after tooth extraction and on non-injured skeleton. Sixty-three 129 Sv/Ev male mice composed the groups: C-Control (saline solution); MTK2-2 mg/Kg of Montelukast (MTK) and MTK4-4 mg/Kg of MTK, daily administered by mouth throughout all experimental periods set at 7, 14, and 21 days post-operative. Dental sockets were analyzed by computed microtomography (microCT), histopathology, and immunohistochemistry. Femurs, L5 vertebra and organs were also removed for observation. Blood was collected for plasma bone and liver markers. Histopathology and microCT analysis revealed early socket repair of MTK2 and MTK4 animals, with significant increased BV/TV at days 14 and 21 compared to C. Higher plasma calcium was detected at days 7 and 21 in MTK4 in comparison to C, while phosphate was significantly increased in MTK2 in the same periods in comparison to C and MTK4. No significant differences were found regarding plasma ALP and TRAP, neither for local TRAP and Runx2 immunolabeling at the healing sockets. Organs did not present histological abnormalities. Increased AST levels have been detected in distinct groups and periods. In general, femur phenotype was improved in MTK treated animals. Collectively, MTK promoted early bone formation after tooth extraction and increased bone quality of femurs and vertebra in a time-dose-dependent manner, and should be considered as an alternative therapy when improved post-extraction socket repair or skeleton preservation is required.

The Multifunctional Family of Mammalian Fatty Acid-Binding Proteins

Fatty acid-binding proteins (FABPs) are small lipid-binding proteins abundantly expressed in tissues that are highly active in fatty acid (FA) metabolism. Ten mammalian FABPs have been identified, with tissue-specific expression patterns and highly conserved tertiary structures. FABPs were initially studied as intracellular FA transport proteins. Further investigation has demonstrated their participation in lipid metabolism, both directly and via regulation of gene expression, and in signaling within their cells of expression. There is also evidence that they may be secreted and have functional impact via the circulation. It has also been shown that the FABP ligand binding repertoire extends beyond long-chain FAs and that their functional properties also involve participation in systemic metabolism. This article reviews the present understanding of FABP functions and their apparent roles in disease, particularly metabolic and inflammation-related disorders and cancers.

Regulatory lipid vicinal diols counteract the biological activity of epoxy fatty acids and can act as biomarkers and mechanisms for disease progression

Polyunsaturated fatty acids (PUFAs) are essential fatty acids required for human health and are obtained primarily from food or synthesized in the body by highly regulated processes. The metabolites of these lipids, formed largely through the action of cyclooxygenase, lipoxygenase, or cytochrome P450 (CYP450) enzymes, are responsible for multiple biological functions including inflammation, tissue repair, cell proliferation, blood vessel permeability, and immune cell behavior. The role of these regulatory lipids in disease has been well studied since their discovery as druggable targets; however, the metabolites generated downstream of these pathways have only recently gained attention for regulating biology. Specifically, the biological activity of lipid vicinal diols formed from the metabolism of CYP450-generated epoxy fatty acids (EpFA) by epoxide hydrolases were previously thought to have little biological activity but increasingly are recognized as promoting inflammation and brown fat adipogenesis, and exciting neurons through the regulation of ion channel activity at low concentrations. These metabolites also appear to balance the action of the EpFA precursor. For example, EpFA demonstrate the ability to resolve inflammation and reduce pain, while some lipid diols, through opposing mechanisms, promote inflammation and pain. This review describes recent studies that highlight the role of regulatory lipids, focusing on the balance between EpFA and their diol metabolites in promoting or resolving disease.

Cytochrome P450 and Other Drug-Metabolizing Enzymes As Therapeutic Targets

Cytochrome P450 and other families of drug-metabolizing enzymes are commonly thought of and studied for their ability to metabolize xenobiotics and other foreign entities as they are eliminated from the body. Equally as important, however, is the homeostatic role that many of these enzymes play in maintaining the proper levels of endogenous signaling molecules such as lipids, steroids, and eicosanoids as well as their ability to modulate protein-protein interactions involved in downstream signaling cascades. Throughout the years, many of these endogenous ligands or protein partners of drug-metabolizing enzymes have been associated with a wide range of disease states from cancer to various cardiovascular, neurologic, or inflammatory diseases, prompting an interest in whether modulation of drug-metabolizing enzyme activity could have a subsequent pharmacological impact or lessening of disease severity. Beyond direct regulation of endogenous pathways, drug-metabolizing enzymes have also been proactively targeted for their ability to activate prodrugs with subsequent pharmacological activity or enhance the efficacy of a coadministered drug by inhibiting the metabolism of that drug through a rationally designed drug-drug interaction (i.e., ritonavir and human immunodeficiency virus antiretroviral therapy). The focus of this minireview will be to highlight research aimed at characterizing cytochrome P450 and other drug-metabolizing enzymes as therapeutic targets. Examples of successfully marketed drugs as well as early research efforts will be discussed. Finally, emerging areas of research utilizing typical drug-metabolizing enzymes to impact clinical outcomes will be discussed. SIGNIFICANCE STATEMENT: Although generally thought of for their drug-metabolizing capabilities, enzymes such as the cytochromes P450, glutathione S-transferases, soluble epoxide hydrolases, and others play a significant role in regulating key endogenous pathways, making them potential drug targets. This minireview will cover various efforts over the years to modulate drug-metabolizing enzyme activity toward pharmacological outcomes.

Soluble epoxide hydrolase deficiency promotes liver regeneration and ameliorates liver injury in mice by regulating angiocrine factors and angiogenesis

BACKGROUND

Soluble epoxide hydrolase (sEH) is a key enzyme for the hydrolysis of epoxyeicosatrienoic acids (EETs) and has been implicated in the pathogenesis of hepatic inflammation, fibrosis, cancer, and nonalcoholic fatty liver disease. However, the role of sEH in liver regeneration and injury remains unclear.

METHODS

This study used sEH-deficient (sEH^-/-) mice and wild-type (WT) mice. Hepatocyte proliferation was assessed by immunohistochemical (IHC) staining for Ki67. Liver injury was evaluated by histological staining with hematoxylin and eosin (H&E), Masson's trichrome, and Sirius red, as well as IHC staining for α-SMA. Hepatic macrophage infiltration and angiogenesis were reflected by IHC staining for CD68 and CD31. Liver angiocrine levels were detected by ELISA. The mRNA levels of angiocrine or cell cycle-related genes were measured by quantitative real-time RT-PCR (qPCR). The protein levels of cell proliferation-related protein and phosphorylated signal transducer and activator of transcription 3 (STAT3) were detected by western blotting.

RESULTS

sEH mRNA and protein levels were significantly upregulated in mice after 2/3 partial hepatectomy (PHx). Compared with WT mice, sEH^-/- mice exhibited a higher liver/body weight ratio and more Ki67-positive cells on days 2 and 3 after PHx. The accelerated liver regeneration in sEH^-/- mice was attributed to angiogenesis and endothelial-derived angiocrine (HGF) production. Subsequently, hepatic protein expression of cyclinD1 (CYCD1) and the downstream direct targets of the STAT3 pathway, such as c-fos, c-jun, and c-myc, were also suppressed post-PHx in sEH^-/- compared to WT mice. Furthermore, sEH deficiency attenuated CCl₄-induced acute liver injury and reduced fibrosis in both CCl₄ and bile duct ligation (BDL)-induced liver fibrosis rodent models. Compared with WT mice, sEH^-/- mice had slightly decreased hepatic macrophage infiltration and angiogenesis. Meanwhile, sEH^-/- BDL mice had more Ki67-positive cells in the liver than WT BDL mice.

CONCLUSIONS

sEH deficiency alters the angiocrine profile of liver endothelial to accelerate hepatocyte proliferation and liver regeneration, and blunts acute liver injury and fibrosis by inhibiting inflammation and angiogenesis. sEH inhibition is a promising target for liver diseases to improve liver regeneration and damage.

Polyunsaturated Fatty Acids: Conversion to Lipid Mediators, Roles in Inflammatory Diseases and Dietary Sources

Polyunsaturated fatty acids (PUFAs) are important components of the diet of mammals. Their role was first established when the essential fatty acids (EFAs) linoleic acid and α-linolenic acid were discovered nearly a century ago. However, most of the biochemical and physiological actions of PUFAs rely on their conversion to 20C or 22C acids and subsequent metabolism to lipid mediators. As a generalisation, lipid mediators formed from n-6 PUFAs are pro-inflammatory while those from n-3 PUFAs are anti-inflammatory or neutral. Apart from the actions of the classic eicosanoids or docosanoids, many newly discovered compounds are described as Specialised Pro-resolving Mediators (SPMs) which have been proposed to have a role in resolving inflammatory conditions such as infections and preventing them from becoming chronic. In addition, a large group of molecules, termed isoprostanes, can be generated by free radical reactions and these too have powerful properties towards inflammation. The ultimate source of n-3 and n-6 PUFAs are photosynthetic organisms which contain Δ-12 and Δ-15 desaturases, which are almost exclusively absent from animals. Moreover, the EFAs consumed from plant food are in competition with each other for conversion to lipid mediators. Thus, the relative amounts of n-3 and n-6 PUFAs in the diet are important. Furthermore, the conversion of the EFAs to 20C and 22C PUFAs in mammals is rather poor. Thus, there has been much interest recently in the use of algae, many of which make substantial quantities of long-chain PUFAs or in manipulating oil crops to make such acids. This is especially important because fish oils, which are their main source in human diets, are becoming limited. In this review, the metabolic conversion of PUFAs into different lipid mediators is described. Then, the biological roles and molecular mechanisms of such mediators in inflammatory diseases are outlined. Finally, natural sources of PUFAs (including 20 or 22 carbon compounds) are detailed, as well as recent efforts to increase their production.

Serotonin-induced stereospecific formation and bioactivity of the eicosanoid 17,18-epoxyeicosatetraenoic acid in the regulation of pharyngeal pumping of C. elegans

17,18-Epoxyeicosatetraenoic acid (17,18-EEQ), the most abundant eicosanoid generated by cytochrome P450 (CYP) enzymes in C. elegans, is a potential signaling molecule in the regulation of pharyngeal pumping activity of this nematode. As a chiral molecule, 17,18-EEQ can exist in two stereoisomers, the 17(R),18(S)- and 17(S),18(R)-EEQ enantiomers. Here we tested the hypothesis that 17,18-EEQ may function as a second messenger of the feeding-promoting neurotransmitter serotonin and stimulates pharyngeal pumping and food uptake in a stereospecific manner. Serotonin treatment of wildtype worms induced a more than twofold increase of free 17,18-EEQ levels. As revealed by chiral lipidomics analysis, this increase was almost exclusively due to an enhanced release of the (R,S)-enantiomer of 17,18-EEQ. In contrast to the wildtype strain, serotonin failed to induce 17,18-EEQ formation as well as to accelerate pharyngeal pumping in mutant strains defective in the serotonin SER-7 receptor. However, the pharyngeal activity of the ser-7 mutant remained fully responsive to exogenous 17,18-EEQ administration. Short term incubations of well-fed and starved wildtype nematodes showed that both racemic 17,18-EEQ and 17(R),18(S)-EEQ were able to increase pharyngeal pumping frequency and the uptake of fluorescence-labeled microspheres, while 17(S),18(R)-EEQ and also 17,18-dihydroxyeicosatetraenoic acid (17,18-DHEQ, the hydrolysis product of 17,18-EEQ) were ineffective. Taken together, these results show that serotonin induces 17,18-EEQ formation in C. elegans via the SER-7 receptor and that both the formation of this epoxyeicosanoid and its subsequent stimulatory effect on pharyngeal activity proceed with high stereospecificity confined to the (R,S)-enantiomer.

Effect of omega-3 ethyl esters on the triglyceride-rich lipoprotein response to endotoxin challenge in healthy young men

Oxylipins are produced enzymatically from polyunsaturated fatty acids, are abundant in triglyceride-rich lipoproteins (TGRL), and mediate inflammatory processes. Inflammation elevates TGRL concentrations, but it is unknown if the fatty acid and oxylipin composition change. In this study, we investigated the effects of prescription ω-3 acid ethyl esters (P-OM3; 3.4 g/d EPA + DHA) on the lipid response to an endotoxin challenge (lipopolysaccharide (LPS); 0.6 ng/kg body weight). Healthy young men (N=17) were assigned 8-12 weeks of P-OM3 and olive oil control in a randomized order crossover study. Following each treatment period, subjects received endotoxin challenge, and the time-dependent TGRL composition was observed. Post-challenge, arachidonic acid (AA) was 16% [95% CI: 4%, 28%] lower than baseline at 8 hours with control. P-OM3 increased TGRL ω-3 fatty acids (EPA 24% [15%, 34%]; DHA 14% [5%, 24%]). The timing of ω-6 oxylipin responses differed by class; AA-derived alcohols peaked at 2 hrs, while linoleic acid (LA)-derived alcohols peaked at 4 hrs (p_int = 0.006). P-OM3 increased EPA alcohols by 161% [68%, 305%] and DHA epoxides by 178% [47%, 427%] at 4 hrs compared to control. In conclusion, this study shows that TGRL fatty acid and oxylipin composition changes following endotoxin challenge. P-OM3 alters the TGRL response by increasing availability of ω-3 oxylipins for resolution of the inflammatory response.

Sorafenib increases cytochrome P450 lipid metabolites in patient with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer death, and medical treatment options are limited. The multikinase inhibitor sorafenib was the first approved drug widely used for systemic therapy in advanced HCC. Sorafenib might affect polyunsaturated fatty acids (PUFA)-derived epoxygenated metabolite levels, as it is also a potent inhibitor of the soluble epoxide hydrolase (sEH), which catalyzes the conversion of cytochrome-P450 (CYP)-derived epoxide metabolites derived from PUFA, such as omega-6 arachidonic acid (AA) and omega-3 docosahexaenoic acid (DHA), into their corresponding dihydroxy metabolites. Experimental studies with AA-derived epoxyeicosatrienoic acids (EETs) have shown that they can promote tumor growth and metastasis, while DHA-derived 19,20-epoxydocosapentaenoic acid (19,20-EDP) was shown to have anti-tumor activity in mice. In this study, we found a significant increase in EET levels in 43 HCC patients treated with sorafenib and a trend towards increased levels of DHA-derived 19,20-EDP. We demonstrate that the effect of sorafenib on CYP- metabolites led to an increase of 19,20-EDP and its dihydroxy metabolite, whereas DHA plasma levels decreased under sorafenib treatment. These data indicate that specific supplementation with DHA could be used to increase levels of the epoxy compound 19,20-EDP with potential anti-tumor activity in HCC patients receiving sorafenib therapy.

The role of clopidogrel resistance-related genetic and epigenetic factors in major adverse cardiovascular events among patients with acute coronary syndrome after percutaneous coronary intervention

Despite patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) and receiving clopidogrel therapy, some patients still experience major adverse cardiovascular events (MACEs). Clopidogrel resistance, which may be regulated by genetic and epigenetic factors, may play a role in MACEs. This study aimed to determine the association between genetic (CYP2C19 and P2Y12 polymorphisms) and epigenetic (DNA methylation of CYP2C19 and P2Y12 and miRNA-26a expression) factors and their effects on MACEs among post-PCI patients. Post-PCI patients who received a standard dosage of clopidogrel at Harapan Kita Hospital between September 2018 and June 2020 were included in this study. MACEs were observed in patients within 1 year after PCI. Platelet aggregation was assessed using light transmission aggregometry (LTA). DNA methylation of CYP2C19 and P2Y12 was assessed using the bisulfite conversion method. CYP2C19 and P2Y12 polymorphisms and miRNA-26a expression were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). Among a total of 201 subjects, 49.8% were clopidogrel-resistant, and 14.9% experienced MACEs within 1 year after PCI (death was 7.5%). Hypomethylation of CYP2C19 (p = 0.037) and miRNA-26a upregulation (p = 0.020) were associated with clopidogrel resistance. CYP2C19^*2/^*3 polymorphisms (p = 0.047) were associated with MACEs in 1 year. This study demonstrated that hypomethylation of CYP2C19 and miRNA-26a upregulation increased the risk of clopidogrel resistance in post-PCI patients, but there was no correlation between clopidogrel resistance and MACEs. However, CYP2C19^*2/^*3 polymorphisms were the factors that predicted MACEs within 1 year.

Alzheimer's Precision Neurology: Epigenetics of Cytochrome P450 Genes in Circulating Cell-Free DNA for Disease Prediction and Mechanism

Precision neurology combines high-throughput technologies and statistical modeling to identify novel disease pathways and predictive biomarkers in Alzheimer's disease (AD). Brain cytochrome P450 (CYP) genes are major regulators of cholesterol, sex hormone, and xenobiotic metabolism, and they could play important roles in neurodegenerative disorders. Increasing evidence suggests that epigenetic factors contribute to AD development. We evaluated cytosine ('CpG')-based DNA methylation changes in AD using circulating cell-free DNA (cfDNA), to which neuronal cells are known to contribute. We investigated CYP-based mechanisms for AD pathogenesis and epigenetic biomarkers for disease detection. We performed a case-control study using 25 patients with AD and 23 cognitively healthy controls using the cfDNA of CYP genes. We performed a logistic regression analysis using the MetaboAnalyst software computer program and a molecular pathway analysis based on epigenetically altered CYP genes using the Cytoscape program. We identified 130 significantly (false discovery rate correction q-value < 0.05) differentially methylated CpG sites within the CYP genes. The top two differentially methylated genes identified were CYP51A1 and CYP2S1. The significant molecular pathways that were perturbed in AD cfDNA were (i) androgen and estrogen biosynthesis and metabolism, (ii) C21 steroid hormone biosynthesis and metabolism, and (iii) arachidonic acid metabolism. Existing evidence suggests a potential role of each of these biochemical pathways in AD pathogenesis. Next, we randomly divided the study group into discovery and validation sub-sets, each consisting of patients with AD and control patients. Regression models for AD prediction based on CYP CpG methylation markers were developed in the discovery or training group and tested in the independent validation group. The CYP biomarkers achieved a high predictive accuracy. After a 10-fold cross-validation, the combination of cg17852385/cg23101118 + cg14355428/cg22536554 achieved an AUC (95% CI) of 0.928 (0.787~1.00), with 100% sensitivity and 92.3% specificity for AD detection in the discovery group. The performance remained high in the independent validation or test group, achieving an AUC (95% CI) of 0.942 (0.905~0.979) with a 90% sensitivity and specificity. Our findings suggest that the epigenetic modification of CYP genes may play an important role in AD pathogenesis and that circulating CYP-based cfDNA biomarkers have the potential to accurately and non-invasively detect AD.

Benzoxazolone-5-Urea Derivatives as Human Soluble Epoxide Hydrolase (sEH) Inhibitors

Inhibition of soluble epoxide hydrolase (sEH) is indicated as a new therapeutic modality against a variety of inflammatory diseases, including metabolic, renal, and cardiovascular disorders. In our ongoing research on sEH inhibitors, we synthesized novel benzoxazolone-5-urea analogues with highly potent sEH inhibitory properties inspired by the crystallographic fragment scaffolds incorporating a single H-bond donor/acceptor pair. The tractable SAR results indicated that the aryl or benzyl fragments flanking the benzoxazolone-urea scaffold conferred potent sEH inhibition, and compounds 31-39 inhibited the sEH activity with IC₅₀ values in the range of 0.39-570 nM. Docking studies and molecular dynamics simulations with the most potent analogue 33 provided valuable insights into potential binding interactions of the inhibitor in the sEH binding region. In conclusion, benzoxazolone-5-ureas furnished with benzyl groups on the urea function can be regarded as novel lead structures, which allow the development of advanced analogues with enhanced properties against sEH.

Anandamide and other N-acylethanolamines: A class of signaling lipids with therapeutic opportunities

N-acylethanolamines (NAEs), including N-palmitoylethanolamine (PEA), N-oleoylethanolamine (OEA), N-arachidonoylethanolamine (AEA, anandamide), N-docosahexaenoylethanolamine (DHEA, synaptamide) and their oxygenated metabolites are a lipid messenger family with numerous functions in health and disease, including inflammation, anxiety and energy metabolism. The NAEs exert their signaling role through activation of various G protein-coupled receptors (cannabinoid CB₁ and CB₂ receptors, GPR55, GPR110, GPR119), ion channels (TRPV1) and nuclear receptors (PPAR-α and PPAR-γ) in the brain and periphery. The biological role of the oxygenated NAEs, such as prostamides, hydroxylated anandamide and DHEA derivatives, are less studied. Evidence is accumulating that NAEs and their oxidative metabolites may be aberrantly regulated or are associated with disease severity in obesity, metabolic syndrome, cancer, neuroinflammation and liver cirrhosis. Here, we comprehensively review NAE biosynthesis and degradation, their metabolism by lipoxygenases, cyclooxygenases and cytochrome P450s and the biological functions of these signaling lipids. We discuss the latest findings and therapeutic potential of modulating endogenous NAE levels by inhibition of their degradation, which is currently under clinical evaluation for neuropsychiatric disorders. We also highlight NAE biosynthesis inhibition as an emerging topic with therapeutic opportunities in endocannabinoid and NAE signaling.

Hydrolysis of polyhydroxy polyunsaturated fatty acid-glycerophosphocholines by Group IIA, V, and X secretory phospholipases A2

It is widely accepted that unesterified polyunsaturated ω-6 and ω-3 fatty acids (PUFA) are converted through various lipoxygenases, cyclooxygenases, and cytochrome P450 enzymes to a range of oxygenated derivatives (oxylipins), among which the polyhydroxides of unesterified PUFA have recently been recognized as cell signaling molecules with anti-inflammatory and pro-resolving properties, known as specialized pro-resolving mediators (SPMs). This study investigates the mono-, di-, and trihydroxy 16:0/PUFA-GPCs, and the corresponding 16:0/SPM-GPC, in plasma lipoproteins. We describe the isolation and identification of mono-, di-, and trihydroxy AA, EPA, and DHA-GPC in plasma LDL, HDL, HDL3, and acute phase HDL using normal phase LC/ESI-MS, as previously reported. The lipoproteins contained variable amounts of the polyhydroxy-PUFA-GPC (0-10 nmol/mg protein), likely the product of lipid peroxidation and the action of various lipoxygenases and cytochrome P450 enzymes on both free fatty acids and the parent GPCs. Polyhydroxy-PUFA-GPC was hydrolyzed to variable extent (20%-80%) by the different secretory phospholipases A₂ (sPLA₂ s), with Group IIA sPLA₂ showing the lowest and Group X sPLA₂ the highest activity. Surprisingly, the trihydroxy-16:0/PUFA-GPC of APHDL was largely absent, while large amounts of unidentified material had migrated in the free fatty acid elution area. The free fatty acid mass spectra were consistent with that anticipated for branched chain polyhydroxy fatty acids. There was general agreement between the masses determined by LC/ESI-MS for the polyhydroxy PUFA-GPC and the masses calculated for the GPC equivalents of resolvins, protectins, and maresins using the fatty acid structures reported in the literature.

Characteristics of cytochrome P450-dependent metabolism in the liver of the wild raccoon, Procyon lotor

Wildlife is exposed to a wide range of xenobiotics in the natural environment. In order to appropriately assess xenobiotic-induced toxicity in wildlife, it is necessary to understand metabolic capacities. Carnivores, in general, have low metabolic abilities, making them vulnerable to a variety of chemicals. Raccoons (Procyon lotor) in the wild have been found to have high levels of xenobiotics. However, little is known about the metabolic capacity of the cytochrome P450 (CYP) enzymes in this species. Thus, this study used liver samples to investigate the characteristics of CYP enzymes in wild raccoons. In 22 wild raccoons, CYP concentrations in hepatic microsomes were examined. To better understand the properties of CYP-dependent metabolism, in vitro metabolic activity studies were performed using ethoxyresorufin, pentoxyresorufin and testosterone as substrates. In addition, three raccoons were fed commercial dog food in the laboratory for one week, and the effects on CYP-dependent metabolism were investigated. In comparison to other mammalian species, raccoons had very low concentrations of CYP in their livers. In an in vitro enzymatic analysis, raccoons' ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin O-depentylase (PROD) metabolic capacities were less than one-fifth and one-tenth of rats', respectively. These results indicate the possible high risk in raccoons if exposed to high levels of environmental xenobiotics because of their poor CYP activity. In this study, the features of CYP-dependent metabolism in wild raccoons are described for the first time.

Crosstalk between Depression and Breast Cancer via Hepatic Epoxide Metabolism: A Central Comorbidity Mechanism

Breast cancer (BC) is a serious global challenge, and depression is one of the risk factors and comorbidities of BC. Recently, the research on the comorbidity of BC and depression has focused on the dysfunction of the hypothalamic–pituitary–adrenal axis and the persistent stimulation of the inflammatory response. However, the further mechanisms for comorbidity remain unclear. Epoxide metabolism has been shown to have a regulatory function in the comorbid mechanism with scattered reports. Hence, this article reviews the role of epoxide metabolism in depression and BC. The comprehensive review discloses the imbalance in epoxide metabolism and its downstream effect shared by BC and depression, including overexpression of inflammation, upregulation of toxic diols, and disturbed lipid metabolism. These downstream effects are mainly involved in the construction of the breast malignancy microenvironment through liver regulation. This finding provides new clues on the mechanism of BC and depression comorbidity, suggesting in particular a potential relationship between the liver and BC, and provides potential evidence of comorbidity for subsequent studies on the pathological mechanism.

Oxylipins as Potential Regulators of Inflammatory Conditions of Human Lactation

Chronic low-grade inflammation can be associated with obesity or subclinical mastitis (SCM), which is associated with poor infant growth in low- to middle-income country settings. It is unknown what physiological mechanisms are involved in low milk supply, but our research group has shown that mothers with low milk supply have higher inflammatory markers. Studies investigating oxylipin signaling have the potential to help explain mechanisms that mediate the impacts of inflammation on milk production. Animal studies have reported various elevated oxylipins during postpartum inflammation, mastitis, and mammary involution in ruminant models. Several investigations have quantified oxylipins in human milk, but very few studies have reported circulating oxylipin concentrations during lactation. In addition, there are technical considerations that must be addressed when reporting oxylipin concentrations in human milk. First, the majority of milk oxylipins are esterified in the triglyceride pool, which is not routinely measured. Second, total milk fat should be considered as a covariate when using milk oxylipins to predict outcomes. Finally, storage and handling conditions of milk samples must be carefully controlled to ensure accurate milk oxylipin quantitation, which may be affected by highly active lipases in human milk.

Quinazoline-4(3H)-one-7-carboxamide Derivatives as Human Soluble Epoxide Hydrolase Inhibitors with Developable 5-Lipoxygenase Activating Protein Inhibition

Soluble epoxide hydrolase (sEH) metabolizes epoxyeicosatrienoic acids (EETs), which are endowed with beneficial biological activities as they reduce inflammation, regulate endothelial tone, improve mitochondrial function, and decrease oxidative stress. Therefore, inhibition of sEH for maintaining high EET levels is implicated as a new therapeutic modality with broad clinical applications for metabolic, renal, and cardiovascular disorders. In our search for new sEH inhibitors, we designed and synthesized novel amide analogues of the quinazolinone-7-carboxylic acid derivative 5, a previously discovered 5-lipoxygenase-activating protein (FLAP) inhibitor, to evaluate their potential for inhibiting sEH. As a result, we identified new quinazolinone-7-carboxamides that demonstrated selective sEH inhibition with decreased FLAP inhibitor properties. The tractable SAR results indicated that the amide and thiobenzyl fragments flanking the quinazolinone nucleus are critical features governing the potent sEH inhibition, and compounds 34, 35, 37, and 43 inhibited the sEH activity with IC₅₀ values of 0.30-0.66 μM. Compound 34 also inhibited the FLAP-mediated leukotriene biosynthesis (IC₅₀ = 2.91 μM). In conclusion, quinazolinone-7-carboxamides can be regarded as novel lead structures, and newer analogues with improved efficiency against sEH along with or without FLAP inhibition can be generated.

Annexin A1 exerts renoprotective effects in experimental crescentic glomerulonephritis

Non-resolving inflammation plays a critical role during the transition from renal injury towards end-stage renal disease. The glucocorticoid-inducible protein annexin A1 has been shown to function as key regulator in the resolution phase of inflammation, but its role in immune-mediated crescentic glomerulonephritis has not been studied so far.

Methods: Acute crescentic glomerulonephritis was induced in annexin A1-deficient and wildtype mice using a sheep serum against rat glomerular basement membrane constituents. Animals were sacrificed at d5 and d10 after nephritis induction. Renal leukocyte abundance was studied by immunofluorescence and flow cytometry. Alterations in gene expression were determined by RNA-Seq and gene ontology analysis. Renal levels of eicosanoids and related lipid products were measured using lipid mass spectrometry.

Results: Histological analysis revealed an increased number of sclerotic glomeruli and aggravated tubulointerstitial damage in the kidneys of annexin A1-deficient mice compared to the wildtype controls. Flow cytometry analysis confirmed an increased number of CD45⁺ leukocytes and neutrophil granulocytes in the absence of annexin A1. Lipid mass spectrometry showed elevated levels of prostaglandins PGE2 and PGD2 and reduced levels of antiinflammatory epoxydocosapentaenoic acid regioisomers. RNA-Seq with subsequent gene ontology analysis revealed induction of gene products related to leukocyte activation and chemotaxis as well as regulation of cytokine production and secretion.

Conclusion: Intrinsic annexin A1 reduces proinflammatory signals and infiltration of neutrophil granulocytes and thereby protects the kidney during crescentic glomerulonephritis. The annexin A1 signaling cascade may therefore provide novel targets for the treatment of inflammatory kidney disease.

Soluble Epoxide Hydrolase Is Associated with Postprandial Anxiety Decrease in Healthy Adult Women

The metabolism of bioactive oxylipins by soluble epoxide hydrolase (sEH) plays an important role in inflammation, and sEH may be a risk modifier in various human diseases and disorders. The relationships that sEH has with the risk factors of these diseases remain elusive. Herein, sEH protein expression and activity in white blood cells were characterized before and after a high-fat meal in healthy women (HW) and women with anorexia nervosa (AN). sEH expression and sEH activity were significantly correlated and increased in both groups two hours after consumption of the study meal. Fasting sEH expression and activity were positively associated with body mass index (BMI) in both groups, while an inverse association with age was found in AN only (p value < 0.05). sEH was not associated with anxiety or depression in either group at the fasting timepoint. While the anxiety score decreased after eating in both groups, a higher fasting sEH was associated with a lower postprandial anxiety decrease in HW (p value < 0.05). sEH characterization using direct measurements verified the relationship between the protein expression and in vivo activity of this important oxylipin modulator, while a well-controlled food challenge study design using HW and a clinical control group of women with disordered eating elucidated sEH’s role in the health of adult women.

A genetic screen for aldicarb resistance of Caenorhabditiselegans dauer larvae uncovers 2 alleles of dach-1, a cytochrome P450 gene

Animals exhibit phenotypic plasticity through the interaction of genes with the environment, and little is known about the genetic factors that change synaptic function at different developmental stages. Here, we investigated the genetic determinants of how animal's sensitivity to drugs that alter synaptic activity is regulated at a specific developmental stage using the free-living nematode Caenorhabditis elegans. C. elegans enters the stress-resistant dauer larval stage under harsh conditions. Although dauer is known to have reduced permeability and increased resistance to most known exogenous chemicals, we discovered that dauer is hypersensitive to a cholinesterase inhibitor, aldicarb. To investigate genes regulating dauer-specific acetylcholine transduction, we first screened for aldicarb-resistant mutations in dauer and then performed a secondary screen to rule out aldicarb-resistant mutations that also affect adults. We isolated 2 different mutations of a single gene called cyp-34A4 or dach-1 encoding a cytochrome P450. In the nondauer stages, dach-1 is mainly expressed in the intestine, but its expression is robustly increased in the epidermis of dauers. By tissue-specific rescue experiments, we found that dach-1 modulates aldicarb sensitivity in a cell nonautonomous manner. In addition, dach-1 plays pleiotropic functions in dauers by regulating quiescence and surviving heat shock and hyperosmolar stress. Our study reveals novel functions of the cytochrome P450 in synaptic and physiological changes during the developmental plasticity.

Protective effects of oyster protein hydrolysates on alcohol-induced liver disease (ALD) in mice: based on the mechanism of anti-oxidative metabolism

Many bioactivities of hydrolysates from oyster (Crassostrea gigas) muscle have been reported, while there is no knowledge about their protective effects on alcohol-induced liver disease (ALD). In the present study, the anti-oxidative activities in vitro and molecular weight distribution of oyster protein hydrolysates (OPH) were detected and the OPH released by alcalase (AOPH) was used to treat C57BL/6 mice. C57BL/6 mice were treated with a Lindros control diet to establish an ethanol-exposed model. The content of small-weight components (<2.0 kDa) of OPH reached 90.85%. AOPH showed more potent antioxidant activities in vitro with higher reducing power and ferric reducing antioxidant power (FRAP), and those capacities could be maintained at a high level after simulated gastrointestinal digestion. Compared to the model mice, oral administration (4 weeks) of AOPH at 800 mg per kg body weight could lead to a decline in T-AOC, GSH-PX, and ADH in the liver. The hepatocellular lesions were effectively relieved and impaired liver tissue development was successfully inhibited. A total of 834 genes and 54 proteins showed differential expression in the AOPH group and the oxidative metabolic pathways of ethanol such as oxidative phosphorylation, glutathione metabolism, peroxisomes, the PPAR signaling pathway and drug metabolism-cytochrome P450 play a preeminent role in ALD according to the results of transcriptomics and proteomics. The beneficial effects of AOPH were available in the improvement of ALD. These results revealed that AOPH intervention ameliorated ALD by affecting oxidative metabolism and highlighting AOPH's potential application as a functional food.

Individual and Joint Effect of Alpha-Tocopherol and Hydroxytyrosol Acetate on the Oxidation of Sunflower Oil Submitted to Oxidative Conditions: A Study by Proton Nuclear Magnetic Resonance

This study tackles the individual and joint effect of alpha-tocopherol and hydroxytyrosol acetate on the oxidation of sunflower oil submitted to accelerated storage conditions at intermediate temperature, in order to deepen the understanding of antioxidant-prooxidant behaviour. This was accomplished by 1H Nuclear Magnetic Resonance. For this purpose, the evolution of the degradation of both the main components of the oil and the aforementioned added compounds was monitored by this technique throughout the storage time. Furthermore, the formation of a very large number of oxylipins and the evolution of their concentration up to a very advanced stage of oil oxidation, as well as the occurrence of lipolysis, were also simultaneously studied. The results obtained show very clearly and thoroughly that in the oxidation process of the oil enriched in binary mixtures, interactions occur between alpha-tocopherol and hydroxytyrosol acetate that notably reduce the antioxidant effect of the latter compound with the corresponding negative consequences that this entails. The methodology used here has proved to be very efficient to evaluate the antioxidant power of mixtures of compounds.

Soluble Epoxide Hydrolase and Diabetes Complications

Type 2 diabetes mellitus (T2DM) can result in microvascular complications such as neuropathy, retinopathy, nephropathy, and cerebral small vessel disease, and contribute to macrovascular complications, such as heart failure, peripheral arterial disease, and large vessel stroke. T2DM also increases the risks of depression and dementia for reasons that remain largely unclear. Perturbations in the cytochrome P450-soluble epoxide hydrolase (CYP-sEH) pathway have been implicated in each of these diabetes complications. Here we review evidence from the clinical and animal literature suggesting the involvement of the CYP-sEH pathway in T2DM complications across organ systems, and highlight possible mechanisms (e.g., inflammation, fibrosis, mitochondrial function, endoplasmic reticulum stress, the unfolded protein response and autophagy) that may be relevant to the therapeutic potential of the pathway. These mechanisms may be broadly relevant to understanding, preventing and treating microvascular complications affecting the brain and other organ systems in T2DM.