Advances in Our Understanding of Oxylipins Derived from Dietary PUFAs

Dihomo-gamma-linolenic acid (DGLA) is inversely related to risk for cardiac death and cardiovascular events during 2 years follow-up after admission for an acute coronary syndrome

BACKGROUND/AIM

Dihomo-gamma-linolenic acid (DGLA) is derived from linoleic acid. Its presence in red blood cell (RBC) membranes is mainly due to metabolism and not diet. RBC DGLA was negatively associated with all-cause mortality during 7 years follow-up in patients admitted with an acute coronary syndrome (ACS). We now present its 2-year cardiovascular prognostic utility compared to other n-6 fatty acids (FAs).

METHODS

A total of 139 females and 259 males with a mean age of 71.9 ± 13.0 years were admitted consecutively in this study. Stepwise Cox regression models, applying continuous values of DGLA weight percent (wt %) and quartiles, were fitted for the biomarkers with cardiac death and a combined cardiovascular (CV) endpoint consisting of cardiac death or myocardial infarction (MI) or stroke as the dependent variables.

RESULTS

Cardiac death was recorded in 57 patients, and the composite CV endpoint in 144 patients, respectively. DGLA was negatively associated with both endpoints, each with a p-value of <0.001 in univariate analysis. The hazard ratio (HR, per 1 wt % increase) remained significant after multivariable adjustment [cardiac death HR 0.51 (95 %CI 0.27-0.98), p = 0.042, and composite CV endpoint HR 0.61 (95 %CI 0.41-0.92), p = 0.017]. A similar pattern was obtained in ACS patients presenting with an acute MI at admission. No association with any outcome was found with the other n-6 FAs [linoleic acid, arachidonic acid and adrenic acid].

CONCLUSION

Higher RBC DGLA predicts lower risk for cardiac death and cardiovascular outcomes at 2 years follow-up in ACS patients, whereas other n-6 FAs do not.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00521976.

Comparative analysis of fatty acid profiles across omnivorous, flexitarians, vegetarians, and vegans: insights from the NuEva study

BACKGROUND

Different dietary choices can influence blood fatty acid profiles, which are crucial for maintaining physiological health and reducing disease risk. In particular, the exclusion of animal foods in vegetarian diets is associated with a higher risk of undersupply of long-chain omega (n)-3 fatty acids, which could, potentially, have a negative effect on inflammation. This study aimed to examine differences in plasma and erythrocyte fatty acid profiles as well as inflammation-related biomarkers between various plant-based diets and a regular omnivores diet.

METHODS

The Nutritional Evaluation (NuEva) study is a is a parallel-designed trial. Here screening data was used to investigate differences in plasma and erythrocyte fatty acid profiles across omnivores (Western diet; n = 62), flexitarians (n = 69), vegetarians (n = 64) and vegans (n = 57). Furthermore, markers associated with inflammation are investigated and correlated with selected fatty acids.

RESULTS

Flexitarians showed lower erythrocyte saturated fatty acids (SFA) than omnivores, while vegans had the lowest plasma SFA. Vegans had higher erythrocyte monounsaturated fatty acids proportions, like oleic acid, than flexitarians and vegetarians. n-6 fatty acids, particularly linoleic acid, were highest in vegans and vegetarians. Conversely, omnivores had higher arachidonic acid in erythrocytes. Vegans had lower n-3 fatty acids in both plasma and erythrocytes, also reflected in a lower n-3 index (eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA)) values, indicating a trend with restriction of animal foods: omnivores/flexitarians > vegetarians > vegans. While interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor (TNF)-α and high-sensitive C-reactive protein (hsCRP) did not differ between groups, and vegans had lower leptin levels compared to omnivores.

CONCLUSIONS

The NuEva study revealed significant impact of dietary patterns on fatty acid profiles, with vegans and vegetarians displaying lower concentrations of SFA and n-3 fatty acids, including EPA and DHA, compared to omnivores and flexitarians. Despite the clear differences in fatty acid profiles across the diets, the inflammatory markers measured in our healthy collective are comparable.

TRIAL REGISTRATION

Registered under ClinicalTrials.gov Identifier no. NCT03582020.

Identifying early predictive and diagnostic biomarkers and exploring metabolic pathways for sepsis after trauma based on an untargeted metabolomics approach

Systemic inflammatory response syndrome (SIRS) and organ dysfunction make it challenging to predict which major trauma patients are at risk of developing sepsis. Additionally, the unclear pathogenesis of sepsis after trauma contributes to its high morbidity and mortality. Identifying early predictive and diagnostic biomarkers, as well as exploring related metabolic pathways, is crucial for improving early prevention, diagnosis, and treatment. This study prospectively analyzed plasma samples from patients with severe trauma collected between March 2022 and November 2023. Trauma patients were divided into two groups based on whether they developed sepsis within two weeks: the TDDS group (trauma patients who did not develop sepsis) and the TDS group (trauma patients who did develop sepsis). Plasma samples from the TDS group were collected at the time of sepsis diagnosis (Sepsis group). Metabolite concentrations were measured using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) through untargeted metabolomics. From the differential metabolites between the TDS and TDDS groups, we identified five significant metabolites (all area under the curve (AUC) ≥ 0.94) as early predictive biomarkers for sepsis after trauma: (1) docosatrienoic acid, (2) 7-alpha-carboxy-17-alpha-carboxyethylandrostan lactone phenyl ester, (3) sphingomyelin (SM) 8:1;2O/26:1, (4) N1-[1-(3-isopropenylphenyl)-1-methylethyl]-3-oxobutanamide, and (5) SM 34:2;2O. Furthermore, five significant metabolites (all AUC ≥ 0.85) were identified as early diagnostic biomarkers from the comparison between the TDS and TDDS groups: (1) lysophosphatidylcholine (LPC) O-22:1, (2) LPC O-22:0, (3) uric acid, (4) LPC O-24:2, and (5) LPC 22:0-SN1. 26 metabolites shared between two comparisons (TDS vs. TDDS and sepsis vs. TDS) were identified. Of which, 19 metabolites belong to lipid metabolism. The top three metabolic pathways related to sepsis after trauma under the impact of severe trauma were: (1) glycerophospholipid metabolism, (2) porphyrin metabolism, and (3) sphingolipid metabolism. The top three metabolic pathways related to sepsis after trauma under the impact of infection were: (1) caffeine metabolism, (2) biosynthesis of unsaturated fatty acids, and (3) steroid hormone biosynthesis. Our study identified early predictive and diagnostic biomarkers and explored metabolic pathways related to sepsis after trauma. These findings provide a foundation for future research on the onset and development of sepsis, facilitating its early prevention, diagnosis, and treatment based on specific metabolites and metabolic pathways.

Metabolic Alteration in Oxylipins and Endocannabinoids Point to an Important Role for Soluble Epoxide Hydrolase and Inflammation in Alzheimer's Disease - Finding from Alzheimer's Disease Neuroimaging Initiative

Mounting evidence implicates inflammation as a key factor in Alzheimer's disease (AD) development. We previously identified pro-inflammatory soluble epoxide hydrolase (sEH) metabolites to be elevated in plasma and CSF of AD patients and to be associated with lower cognition in non-AD subjects. Soluble epoxide hydrolase is a key enzyme converting anti-inflammatory epoxy fatty acids to pro-inflammatory diols, reported to be elevated in multiple cardiometabolic disorders. Here we analyzed over 700 fasting plasma samples from the baseline of Alzheimer's Disease Neuroimaging Initiative (ADNI) 2/GO study. We applied targeted mass spectrometry method to provide absolute quantifications of over 150 metabolites from oxylipin and endocannabinoids pathway, interrogating the role for inflammation/immune dysregulation and the key enzyme soluble epoxide hydrolase in AD. We provide further insights into the regulation of this pathway in different disease stages, APOE genotypes and between sexes. Additionally, we investigated in mild cognitive impaired (MCI) patients, metabolic signatures that inform about resilience to progression and conversion to AD. Key findings include I) confirmed disruption in this key central pathway of inflammation and pointed to dysregulation of sEH in AD with sex and disease stage differences; II) identified markers of disease progression and cognitive resilience using sex and ApoE genotype stratified analysis highlighting an important role for bile acids, lipid peroxidation and stress response hormone cortisol. In conclusion, we provide molecular insights into a central pathway of inflammation and links to cognitive dysfunction, suggesting novel therapeutic approaches that are based on targeting inflammation tailored for subgroups of individuals based on their sex, APOE genotype and their metabolic profile.

Flavor Profile of 4-Isothiocyanato-1-butene in Microwave Rapeseed Oil and Its Anti-Inflammatory Properties In Vitro

4-Isothiocyanato-1-butene (4-BITC) is a crucial plant isothiocyanate; however, its flavor profile in microwave rapeseed oil and its anti-inflammatory properties have not been elucidated in detail. Therefore, in this study, the distribution of 4-BITC in 45 rapeseed oils was quantitated using selected ion monitoring, with concentrations ranging from 0.29 to 8.63 mg/kg. The odor activity values ranged from 4 to 123. In a lipopolysaccharide (LPS)-induced RAW264.7 cell model, 4-BITC exerted dose-dependent anti-inflammatory effects, which resulted in remarkable differences in 20 lipid mediators between the LPS and 4-BITC groups. Kyoto Encyclopedia of Genes and Genomes analysis revealed that 4-BITC downregulated proinflammatory oxylipins by modulating the CYP, LOX, and COX pathways, thereby preventing arachidonic acid metabolism disorders. Molecular docking further confirmed that 4-BITC inhibited the PI3K/Akt/NF-κB signaling cascade to alleviate inflammation.

Alcohol Reprograms Placental Glucose and Lipid Metabolism, Which Correlate with Reduced Fetal Brain but not Body Weight in a Mouse Model of Prenatal Alcohol Exposure

BACKGROUND

Prenatal alcohol exposure (PAE) impairs fetal growth and brain development. Dysregulated placental function contributes to these deficits. Whether PAE also disrupts its metabolic functions to impede fetal development is unclear.

OBJECTIVES

We performed untargeted metabolomics to gain mechanistic insights on how PAE impacts placental metabolism and fetal nutrient availability.

METHODS

Pregnant C57BL/6J mice were gavaged with alcohol (ALC, 3 g/kg) or isocaloric maltodextrin (CON) daily on embryonic days (E) E8.5 through E17.5. We performed untargeted metabolomics on placentas harvested at E17.5.

RESULTS

Alcohol reduced placental glucose and glycolytic intermediates and increased tricarboxylic acid (TCA) cycle intermediates, suggesting a shift from glucose to lipids to meet its high energetic demands. This was complemented by elevations in intermediates of the pentose phosphate and glucosamine pathways, indicating a diversion of glucose into nonoxidative fates. Alcohol also decreased aspartate and asparagine, consistent with the limited glucose availability and increased fetal demand for nitrogen acceptors to support its increased gluconeogenesis and urea production. Alcohol also caused a selective increase in purine metabolites despite the limited availability of donor sources glucose, serine, glycine, glutamine, and asparagine. Uridine nucleotides were also elevated and may represent an adaptive change to meet the increased need for thiamin pyrophosphate in the oxidative decarboxylations of the TCA cycle and pentose phosphate pathways. Decreases in multiple oxylipins having antivasoconstriction actions could be a mechanism by which alcohol alters the placental vasculature and promotes vasoconstriction. Importantly, the selective and strong correlation of these dysregulated metabolites with reduced fetal brain weight, but not body weight, affirms the importance of the placenta-brain axis and placental metabolism on brain development.

CONCLUSIONS

Alcohol causes metabolic dysregulation and reprogramming of the late-term placenta. These changes limit fetal nutrient availability and contribute to the reduced brain development and cognitive impairments that partly typify PAE.

Cardiovascular Biomarkers: Tools for Precision Diagnosis and Prognosis

The present study provides a detailed review of cardiovascular biomarkers critical for the diagnosis, prognosis, and pathophysiology of cardiovascular diseases, the leading cause of global morbidity and mortality. These biomarkers aid in detecting disease onset, progression, and therapeutic responses, providing insights into molecular mechanisms. Enzyme markers like AST, CK-MB, LDH, CA-III, and HBDH are pivotal for detecting myocardial injury during acute events. Protein markers such as CRP, H-FABP, and MPO shed light on inflammation and oxidative stress. Cardiac Troponins, the gold standard for myocardial infarction diagnosis, exhibit high specificity and sensitivity, while IMA and GPBB indicate ischemia and early myocardial damage. Peptide markers, including BNP and NT-proBNP, are crucial for heart failure diagnosis and management, reflecting ventricular stress and remodeling. Novel peptides like MR-proANP and MR-proADM aid in assessing disease severity. Lipid markers such as lipoprotein-associated phospholipase A2 and oxylipins provide insights into lipid metabolism and atherosclerosis. Inflammatory and stress-related biomarkers, including TNFα, IL-6, GDF-15, and Pentraxin 3, illuminate chronic inflammation in CVDs. Hormonal markers like copeptin and endothelin-1 highlight neurohormonal activation, while emerging markers such as ST2, galectin-3, PAPP-A, and TMAO elucidate fibrosis, remodeling, and metabolic dysregulation. The inclusion of microRNAs and long non-coding RNAs represents a breakthrough in biomarker research, offering sensitive tools for early detection, risk stratification, and therapeutic targeting. This review emphasizes the diagnostic and prognostic utility of these biomarkers, advancing cardiovascular care through personalized medicine.

Decreased plasma lipoxin A4, resolvin D1, protectin D1 are correlated with the complexity and prognosis of coronary heart disease: A retrospective cohort study

This study aimed to assess the predictive capacity of specialized pro-resolving mediators (SPMs) regarding the complexity and prognosis of coronary heart disease (CHD). Total of 602 CHD patients were included in this study and categorized into low-risk, medium-risk, and high-risk groups based on the Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score. Follow-up was conducted for two years, during which patients were dichotomized into poor and good prognosis groups. Additionally, twenty healthy controls were incorporated. Plasma concentrations of lipoxin A4 (LXA4), resolvin D1 (RvD1), protectin D1 (PD1), C-reactive protein (CRP), interleukin-6 (IL-6), and IL-10 were quantified. Plasma LXA4, RvD1, PD1, and the ratios LXA4/IL-6, RvD1/IL-6, PD1/IL-6 exhibited a gradual decrease across control, low-risk, medium-risk, and high-risk groups and exhibited a negative correlation with the SYNTAX score. Spearman's correlation analysis revealed negative correlations between plasma LXA4, RvD1, PD1, and both CRP and IL-6, and positive correlations with IL-10. Multiple linear regression models demonstrated negative associations between plasma LXA4, RvD1, PD1, and SYNTAX score. Moreover, both univariate and multivariate binary logistic regression analyses identified plasma LXA4, RvD1, and PD1 as protective factors against medium/high-risk SYNTAX score categorization. In the poor prognosis group, plasma PD1 was reduced at short-term follow-up, and the ratios LXA4/IL-6, RvD1/IL-6, PD1/IL-6 were reduced at long-term follow-up. Plasma LXA4, RvD1, and PD1 demonstrated negative correlations with CHD complexity and potentially served as protective factors against CHD. Plasma PD1 provided predictive value for short-term prognosis, while the ratios LXA4/IL-6, RvD1/IL-6, PD1/IL-6 were indicative for long-term prognosis.

Functional characterization of eicosanoid signaling in Drosophila development

20-carbon fatty acid-derived eicosanoids are versatile signaling oxylipins in mammals. In particular, a group of eicosanoids termed prostanoids are involved in multiple physiological processes, such as reproduction and immune responses. Although some eicosanoids such as prostaglandin E2 (PGE2) have been detected in some insect species, molecular mechanisms of eicosanoid synthesis and signal transduction in insects have not been thoroughly investigated. Our phylogenetic analysis indicated that, in clear contrast to the presence of numerous receptors for oxylipins and other lipid mediators in humans, the Drosophila genome only possesses a single ortholog of such receptors, which is homologous to human prostanoid receptors. This G protein-coupled receptor, named Prostaglandin Receptor or PGR, is activated by PGE2 and its isomer PGD2 in Drosophila S2 cells. PGR mutant flies die as pharate adults with insufficient tracheal development, which can be rescued by supplying high oxygen. Consistent with this, through a comprehensive mutagenesis approach, we identified a Drosophila PGE synthase whose mutants show similar pharate adult lethality with hypoxia responses. Drosophila thus has a highly simplified eicosanoid signaling pathway as compared to humans, and it may provide an ideal model system for investigating evolutionarily conserved aspects of eicosanoid signaling.

Deeper insights into the stability of oxylipins in human plasma across multiple freeze-thaw cycles and storage conditions

Oxylipins are signaling lipids derived from the oxidation of polyunsaturated fatty acids (PUFAs). In lipidomic studies, human plasma may be subjected to various storage conditions and freeze-thaw cycles, which may impact the analysis of these compounds. In this study, we used liquid chromatography coupled with mass spectrometry (LC-MS) to examine the influence of up to five freeze-thaw cycles (FTCs) on free and total (mostly esterified) oxylipins in human plasma and the influence of temperature and storage duration (4 °C for up to 120 h and -20 °C and -80 °C for 1-98 days) in the presence or absence of butylated hydroxytoluene (BHT) on extracted oxylipins stored in LC-MS amber vials. In fresh plasma subjected to several FTCs, approximately 48 % of the detected free oxylipins were significantly altered by the third cycle, with increases in cytochrome P450 (CYP450) and lipoxygenase (LOX)-derived compounds and reductions in trihydroxylated oxylipins. In contrast, multiple FTCs did not significantly alter esterified oxylipins. At 4 °C, the extracted oxylipins did not change significantly for up to 120 h (5 days). Oxylipin levels remained stable for 98 days at -80 °C but decreased by 98 days at -20 °C. The antioxidant activity of butylated hydroxytoluene (BHT) did not influence oxylipin stability at 4 °C for 120 h or at -80 °C for 98 days, but it reduced oxylipin degradation at -20 °C at 98 days. Conversely, prostaglandin F2α (PGF2α) exhibited substantial increases at -20 °C and -80 °C, independent of BHT. This study demonstrates that (i) unlike free oxylipins, the esterified oxylipin pool remains stable following repeated FTCs, (ii) extracted oxylipins are stable at 4 °C for up to 120 h and at -80 °C for up to 98 days, but not at -20 °C for 98 days, and (iii) BHT may minimize oxylipin degradation of sample extracts stored at -20 °C. This study provides a framework for measuring oxylipins under various freeze-thaw and storage conditions.

Omega-6 polyunsaturated fatty acids and their metabolites: a potential targeted therapy for pulmonary hypertension

Pulmonary hypertension (PH) is a progressive and life-threatening cardiopulmonary disease that is not uncommon. The modulation of the pulmonary artery (PA) involves various fatty acids, including omega-6 polyunsaturated fatty acids (ω-6 PUFAs) and ω-6 PUFAs-derived oxylipins. These lipid mediators are produced through cyclooxygenase (COX), lipoxygenase (LOX), cytochrome P450 (CYP450), and non-enzymatic pathways. They play a crucial role in the occurrence and development of PH by regulating the function and phenotype of pulmonary artery endothelial cells (PAECs), pulmonary artery smooth muscle cells (PASMCs), pulmonary fibroblasts, alveolar macrophages, and inflammatory cells. The alterations in ω-6 PUFAs and oxylipins are pivotal in causing vasoconstriction, pulmonary remodeling, and ultimately leading to right heart failure in PH. Despite the limited understanding of the PH pathophysiology, there is potential for novel interventions through dietary and pharmacological approaches targeting ω-6 PUFAs and oxylipins. The aim of this review is to summarize the significant advances in clinical and basic research on omega-6 PUFAs and oxylipins in pulmonary vascular disease, particularly PH, and to propose a potential targeted therapeutic modality against omega-6 PUFAs.

Dietary and circulating omega-6 fatty acids and their impact on cardiovascular disease, cancer risk, and mortality: a global meta-analysis of 150 cohorts and meta-regression

BACKGROUND

Despite the significant increase in omega-6 fatty acid consumption, evidence regarding their health impacts remains inconsistent. This study performs an umbrella review and updated meta-analysis to evaluate the association between dietary and circulating omega-6 levels and the risks of cardiovascular diseases (CVDs), cancer, and mortality.

METHODS

A systematic search was conducted in PubMed, Scopus, and Web of Science until January 2024 to identify eligible meta-analyses of prospective observational studies. The Cochrane risk of bias and GRADE tools were used to assess the risk of bias and certainty of the evidence, respectively.

RESULTS

Analysis of 150 publications revealed that higher dietary intake and circulating levels of omega-6 were associated with lower risks of CVDs, cancer incidence, and all-cause mortality in the general population, particularly for coronary heart disease and stroke. While omega-6 intake was linked to lower risks of lung and prostate cancers, it was associated with higher risks of ovarian and endometrial cancers. Subgroup analyses revealed that these protective associations were more pronounced in cohort studies and absent in populations with pre-existing health conditions.

CONCLUSIONS

Higher dietary intake and circulating levels of omega-6 fatty acids were associated with lower risks of CVDs, cancers, and all-cause mortality. However, the associations vary by cancer type and are less evident in individuals with pre-existing health conditions. These findings highlight the potential benefits of omega-6 fatty acids for public health while underscoring the need for further research to address specific risks and underlying mechanisms.

TRIAL REGISTRATION

Registration number (PROSPERO): CRD42024522842.

ATP Alters the Oxylipin Profiles in Astrocytes: Modulation by High Glucose and Metformin

Background: Astrocytes play a key role in the inflammatory process accompanying various neurological diseases. Extracellular ATP accompanies inflammatory processes in the brain, but its effect on lipid mediators (oxylipins) in astrocytes remains elusive. Metformin is a hypoglycemic drug with an anti-inflammatory effect that has been actively investigated in the context of therapy for neuroinflammation, but its mechanisms of action are not fully elucidated. Therefore, we aimed to characterize the effects of ATP on inflammatory markers and oxylipin profiles; determine the dependence of these effects on the adaptation of astrocytes to high glucose levels; and evaluate the possibility of modulating ATP effects using metformin. Methods: We estimated the ATP-mediated response of primary rat astrocytes cultured at normal (NG, 5 mM) and high (HG, 22.5 mM) glucose concentrations for 48 h before stimulation. Cell responses were assessed by monitoring changes in the expression of inflammatory markers (TNFα, IL-6, IL-10, IL-1β, iNOS, and COX-2) and the synthesis of oxylipins (41 compounds), assayed with ultra-high-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). Intracellular pathways were assessed by analyzing the phosphorylation of p38; ERK MAPK; transcription factors STAT3 and NF-κB; and the enzymes mediating oxylipin synthesis, COX-1 and cPLA2. Results: The stimulation of cells with ATP does not affect the expression of pro-inflammatory markers, increases the activities of p38 and ERK MAPKs, and activates oxylipin synthesis, shifting the profiles toward an increase in anti-inflammatory compounds (PGD2, PGA2, 12-HHT, and 18-HEPE). The ATP effects are reduced in HG astrocytes. Metformin potentiated ATP-induced oxylipin synthesis (11-HETE, PGD2, 12-HHT, 15-HETE, 13-HDoHE, and 15-HETrE), which was predominantly evident in NG cells. Conclusions: Our data provide new evidence showing that ATP induces the release of anti-inflammatory oxylipins, and metformin enhances these effects. These results should be considered in the development of anti-inflammatory therapeutic approaches aimed at modulating astrocyte function in various pathologies.

Differential Psychopathology Associations Found for Docosahexaenoic Acid versus Arachidonic Acid Oxylipins of the Cytochrome P450 Pathway in Anorexia Nervosa

Anorexia nervosa (AN) is one of the deadliest disorders in psychiatry. AN patients tend to avoid high-fat and high-calorie foods to maintain a pathologically low body weight. High-fat foods are major sources of polyunsaturated fatty acids (PUFAs), lipids that are crucial for health and brain development. PUFAs can be categorized into different omega classes (n-3, n-6) or into essential (ALA, LA) versus nonessential PUFAs (EPA, DHA, ARA). PUFAs are metabolized by Cytochrome P450 (CYP450) enzymes into bioactive oxylipins with inflammation-resolving properties termed epoxy-fatty acids (EpFAs). EpFAs are further hydrolyzed into pro-inflammatory diol-fatty acids (DiHFAs) by soluble epoxide hydrolase (sEH), the protein product of an AN risk gene, EPHX2 . Using a meal challenge study protocol, EpFA and DiHFA oxylipins and sEH were analyzed in age-matched AN and healthy women to determine if sEH-associated oxylipins affect AN risk and psychopathology. At the fasting timepoint, half of the oxylipins were lower in AN compared to controls (all p<0.050). After eating, all but one EpFAs increased in AN (p=0.091 to 0.697) whereas all EpFAs decreased in controls (p=0.0008 to 0.462). By contrast, essential PUFA-derived DiHFAs significantly increased, whereas nonessential PUFA-derived DiHFAs significantly decreased in both groups. DiHFA oxylipins associated with AN psychopathology displayed a PUFA-dependent directionally opposite pattern: n-3 DHA-derived DiHFAs (DiHDPEs) were associated with lower severity in eating disorder risk, global psychological maladjustment, shape and restraint concerns, and global Eating Disorder Examination score. By contrast, n-6 ARA-derived DiHFAs (DiHETrEs) were associated with more severe emotional dysregulation, bulimia, interoceptive deficits, asceticism, and overcontrol scores. On the other hand, EpFA oxylipins were not significantly associated with AN psychopathology. This study confirms lipid metabolic dysregulation as a risk factor for AN. CYP450 oxylipins associated with AN risk and symptoms are sEH- and PUFA class-dependent. Our findings reveal that gene-diet interactions contribute to metabolic dysregulation in AN, highlighting a need for additional research to develop precision medicine for AN management.

Almond consumption for 8 weeks differentially modulates metabolomic responses to an acute glucose challenge compared to crackers in young adults

This study investigated the dynamic responses to an acute glucose challenge after 8 weeks of almond or cracker consumption (clinicaltrials.gov ID: NCT03084003). Young adults (n = 73, age: 18-19 years, BMI: 18-41 kg/m2) participated in an 8-week randomized, controlled, parallel-arm intervention and were assigned to consume either almonds (2 oz/d, n = 38) or an isocaloric control snack of graham crackers (325 kcal/d, n = 35) daily. Twenty participants from each group underwent a 2-hour oral glucose tolerance test (oGTT) at the end of the intervention. Metabolite abundances in the oGTT serum samples were quantified using untargeted metabolomics, and targeted analyses for free PUFAs, total fatty acids, oxylipins, and endocannabinoids. We hypothesized that 8-week almond consumption would differentially modulate the metabolomic response to a glucose challenge compared to crackers. Multivariate, univariate, and chemical enrichment analyses were conducted to identify significant metabolic shifts. Findings exhibit a biphasic lipid response with higher levels of unsaturated triglycerides earlier in the oGTT followed by lower levels later in the almond vs cracker group (p-value <.05, chemical enrichment analyses). Almond (vs cracker) consumption was also associated with higher AUC120 min of aminomalonate, and oxylipins (P-value <.05), but lower AUC120 min of l-cystine, N-acetylmannosamine, and isoheptadecanoic acid (P-value <.05). Additionally, the Matsuda Index in the almond group correlated with AUC120 min of CE 22:6 (r = -0.46; P-value <.05) and 12,13 DiHOME (r = 0.45; P-value <.05). Almond consumption for 8 weeks leads to dynamic, differential shifts in response to an acute glucose challenge, marked by alterations in lipid and amino acid mediators involved in metabolic and physiological pathways.

Effect of fish oil in Iberian sow diets on fatty acid, oxylipins and immune traits of colostrum and milk, and suckling piglets' growth performance

Iberian sow productivity is characterised by a low number of weaned piglets with higher within-litter variation in piglet birth BW compared with conventional breeds. To overcome this, nutritional strategies, such as the dietary addition of n-3 fatty acids (FAs), are being studied to improve sow performance, as well as colostrum and milk composition. In addition, n-3 FAs and their derived oxylipins could also be beneficial for the offspring due to their anti-inflammatory roles. The present study was conducted in an outdoor production system where sows were group-fed during the mating and gestation periods, while feed intake was provided individually during lactation. The study aimed to evaluate the effects of including fish oil rich in eicosapentaenoic and docosahexaenoic acids (EPA and DHA, respectively) in Iberian sow diets on litter size, piglet growth during lactation, and the concentrations of anti-inflammatory molecules in colostrum and milk. Forty sows were randomly assigned to either a control or fish oil diet during pregnancy and lactation. Sow performance and litter traits were monitored until weaning. Colostrum and milk were collected after the birth of the first piglet and at weaning, respectively. Their FA composition, oxylipin profile, and immune indicators were analysed. Despite the piglets from the control group having greater average birth BW than those from the fish oil litters (P = 0.016), the fish oil piglets were heavier at weaning (P < 0.028). Total n-3 FA concentration was increased in the colostrum and milk of fish oil-fed sows (all P < 0.001), mainly due to increases in EPA and DHA concentrations (all P < 0.001). In the same way, most of their oxygenated derivatives were also increased in both colostrum and milk (P ≤ 0.045). The colostrum from fish oil-fed sows also presented higher concentrations of immunoglobulins (Ig) G and A than that from control sows (P = 0.025 and P = 0.026, respectively). In conclusion, the inclusion of fish oil in sow diets increased the levels of IgG and IgA in colostrum, n-3 FAs and their derived oxylipins in colostrum and milk, and piglet BW at weaning.

Sex differences in the central and peripheral omega 3 oxylipin response to acute systemic inflammation

High-density lipoprotein (HDL) oxylipins regulate inflammation, and acute systemic inflammation can precipitate cognitive impairment. Females have more HDL and stronger immune responses than males, yet higher dementia risk. Little is known about sex differences in oxylipin responses to inflammatory stimuli and potential crosstalk between acute systemic inflammation and central oxylipin signaling in either sex. In this targeted lipidomics study, we used liquid chromatography with tandem mass spectrometry (LC/MS/MS) to characterize oxylipin profiles in plasma HDL and cerebrospinal fluid (CSF) of male and female rats following an intraperitoneal interleukin-1β (IL-1β)-induced inflammatory challenge to determine whether and how peripheral and central oxylipins respond to acute systemic inflammation in both sexes. We hypothesized that females mount a greater oxylipin response to IL-1β than males and that acute activation of peripheral inflammatory pathways changes central oxylipin concentrations. We found that IL-1β altered the abundance of omega (ω)6 and ω3 oxylipins in plasma HDL and CSF of both sexes. However, IL-1β reduced global concentrations of peripheral and central oxylipins in plasma HDL and CSF, respectively, in female rats only. Reduced oxylipin concentrations in IL-1β-treated females were driven by a loss of anti-inflammatory ω3 eicosapentaenoic acid (EPA)-derived dihydroxyeicosatetraenoic acids (DiHETEs) in plasma HDL and CSF. Interestingly, plasma HDL and CSF concentrations of EPA-derived DiHETEs were only correlated in IL-1β-treated rats, suggesting increased periphery-brain crosstalk during acute systemic inflammation. Overall, the sexually dimorphic responses of peripheral and central oxylipins to acute systemic inflammation provide molecular insight into sex differences in both innate immunity and neuroinflammatory responses.NEW & NOTEWORTHY This study examines previously unexplored sex differences in oxylipin signaling cascade activation in the central nervous system and periphery during the acute phase response. This is the first study to assess and correlate oxylipins in plasma HDL and CSF in males and females following an acute systemic inflammatory challenge. This work showing reduced concentrations of anti-inflammatory ω3 EPA-derived DiHETEs in acutely inflamed females provides molecular insight into sex differences in immunity and inflammation-induced neurological changes.

Development of an Oxylipin Library Using Liquid Chromatography-Ion Mobility Quadrupole Time-of-Flight: Application to Mouse Brain Tissue

Oxylipins are bioactive lipid mediators derived from polyunsaturated fatty acids (PUFAs) that play crucial roles in physiological and pathological processes. The analysis and identification of oxylipins are challenging due to the numerous isomeric forms. Ion mobility (IM), which separates ions based on their spatial configuration, combined with liquid chromatography (LC) and mass spectrometry (MS), has been proven effective for separating isomeric compounds. In this study, we developed an extensive oxylipin library containing information on retention time (RT), m/z, and CCS values for 74 oxylipin standards using LC-IM-QTOF-MS in positive and negative ionization modes. The oxylipins in the library were grouped into 15 isomer categories to evaluate the efficacy of IM in isomeric separation. Various adducts were investigated, including protonated, deprotonated, and sodiated forms. The ΔCCS% for more than 1000 isomeric pairs was calculated, revealing that 30% of these exhibited a ΔCCS% greater than 2%. Positive ionization mode demonstrated superior separation capabilities, with 274 isomer pairs achieving baseline separation (ΔCCS% >  4%). Sodium adducts significantly improved isomer separation. With the inclusion of LC separation, only nine oxylipins coeluted, forming six different isomeric pairs. CCS values for the adducts [M+Na]+ and [M+2Na-H]+ separated three of these isomeric pairs. The CCS values were compared to experimental libraries, confirming the high reproducibility of CCS measurements, with average errors below 2%. Applying this library to mouse brain samples, 19 different oxylipins were identified by matching RT, m/z, and CCS values. Coeluting isomers, 9- and 13-HODE, 8- and 12-HETE, and 15-oxo-ETE and 14(15)-EpETrE, were successfully separated and identified using drift time separation.

Extracorporeal photopheresis induces the release of anti-inflammatory fatty acids and oxylipins and suppresses pro-inflammatory sphingosine-1-phosphate

AIMS

Extracorporeal photopheresis (ECP) is a UVA-based phototherapy of whole blood and well established as a first line or combination therapy for the treatment of cutaneous T-cell lymphoma, systemic sclerosis, graft-versus-host disease and is used to control organ transplant rejection. While the proapoptotic activity on activated T-cells is evident, the clinical efficacy of this treatment also appears to be based on other yet unknown mechanisms. In this study, we aimed to identify novel mechanisms of ECP regardless of the patient's background situation.

MAIN METHODS

To better understand the immediate consequences of ECP, we analyzed blood plasma of patients with different ECP indications immediately before and after treatment with regard to proteins and lipid mediators.

KEY FINDINGS

While proteome profiling identified substantial inter-individual differences in the protein composition, no significant alteration was detectable upon treatment. In contrast, several fatty acids and lipid mediators were found to be significantly altered by ECP. Remarkably, upregulated lipid mediators including polyunsaturated fatty acids, 12-HEPE and 13-OxoODE have been described to be anti-inflammatory, while the downregulated molecules sphingosine-1-phosphate (S1P) and stearic acid are potent pro-inflammatory mediators. A selective sphingosine-1-phosphate-1 receptor (S1P1) modulator AUY954, which decreases S1P1 and experimentally reduces transplant rejection in vivo, showed greater anti-proliferative activity in human lung fibroblasts from COPD patients compared to normal lung fibroblasts, confirming that this pathway may be important in ECP and its mode of action.

SIGNIFICANCE AND OUTLOOK

In conclusion, we suggest that the ECP-induced changes in lipid mediators may contribute to the remarkable anti-inflammatory effects of the treatment. Depending on their lipid status, patients may benefit from novel treatment regimens combining ECP with lipid modulators. This could be used for the prevention of transplant organ rejection, the treatment of acute or chronic GvHD or transplant organ rejection and the long-term treatment of various skin diseases. This study uncovers novel mechanisms of ECP, that can be used to establish clinically relevant lipid profiles of patients to support patient stratification, predictive or prognostic purposes and thus personalized medical care in the framework of PPPM practice. A combination with S1P modulators may therefore have beneficial effects.

Oxylipin Profiling of Airway Structural Cells Is Unique and Modified by Relevant Stimuli

Oxylipins, diverse lipid mediators derived from fatty acids, play key roles in respiratory physiology, but the contribution of lung structural cells to this diverse profile is not well understood. This study aimed to characterize the oxylipin profiles of airway smooth muscle (ASM), lung fibroblasts (HLF), and epithelial (HBE) cells and define how they shift when they are exposed to stimuli related to contractility, fibrosis, and inflammation. Using HPLC-MS/MS, 162 oxylipins were measured in baseline media from cultured human ASM, HLF, and HBE cells as well as after stimulation with modulators of contractility and central regulators of fibrosis/inflammation. At the baseline, ASM and HLF cells had the most similar oxylipin profiles, dominated by oxylipins from cytochrome P450 (CYP450) epoxygenase metabolites. TGFβ stimulation of HLF suppressed CYP450-derived oxylipins, while ASM stimulation increased prostaglandin production. HBE showed the most distinct baseline profile enriched with cyclooxygenase (COX)-derived oxylipins. TGFβ stimulation of HBE increased the level of several oxylipins from CYP450 epoxygenases. These findings highlight the importance of CYP450 oxylipins, which are relatively unexplored in the context of respiratory physiology. By resolving these oxylipin profiles, we enable future respiratory research to understand the function of these oxylipins in regulating physiology, especially in the context of modifying contraction and inflammation.

Integration of LC-MS-based untargeted and targeted metabolomics to uncover novel whole-grain wheat dietary intake biomarkers in the plasma of the Chinese population

Biomarkers of food intake (BFIs) for whole grains (WGs) would enable more precise dietary assessments and help investigate WG's health effects. However, no reports have been published on the biomarkers that reflect the intake of WG wheat in the Chinese diet. In an acute, randomized, crossover intervention study performed on 22 Chinese subjects, WG wheat BFI candidates were screened using an LC-HRMS untargeted metabolomics technique. Screening results indicate that alkylresorcinol (AR) metabolites are WG wheat-specific metabolites. These metabolites were systematically characterized by in vitro metabolism reaction, and the matched high-throughput LC-MS/MS-targeted quantitative method was developed. Time-response plots generated via targeted analysis revealed AR oxidation products (AR-OOH) and their sulfate conjugates (AR-OOH-sul) increased rapidly following the WG wheat consumption, which were identified as novel and short-term WG wheat BFIs. Another attractive biomarker was glucuronidated ARs (AR-glu), which can distinguish between WG and refined grain (RG) groups 24 h after WG wheat ingestion and is considered a promising medium- and long-term biomarker. Subsequently an independent dose-response study was performed for 38 volunteers who consumed different WG wheat amounts (0, 25, 50 or 100 g) for further validation. Identified BFIs perform well in classifying participants into WG wheat consumers or non-consumers, and could capture dose-dependent changes with WG intake increased. Overall, this is the first study to discover and validate WG BFIs in the Chinese population via dietary intervention trials, indicating the potential usefulness for WG wheat intake assessments and dietary compliance monitoring. Future work will examine their use in large-scale free-living populations.

Metabolic pathways of eicosanoids-derivatives of arachidonic acid and their significance in skin

The skin is a barrier that protects the human body against environmental factors (physical, including solar radiation, chemicals, and pathogens). The integrity and, consequently, the effective metabolic activity of skin cells is ensured by the cell membrane, the important structural and metabolic elements of which are phospholipids. Phospholipids are subject to continuous transformation, including enzymatic hydrolysis (with the participation of phospholipases A, C, and D) to free polyunsaturated fatty acids (PUFAs), which under the influence of cyclooxygenases (COX1/2), lipoxygenases (LOXs), and cytochrome P450 (CYPs P450) are metabolized to various classes of oxylipins, depending on the type of PUFA being metabolized and the enzyme acting. The most frequently analyzed oxylipins, especially in skin cells, are eicosanoids, which are derivatives of arachidonic acid (AA). Their level depends on both environmental factors and endogenous metabolic disorders. However, they play an important role in homeostasis mechanisms related to the structural and functional integrity of the skin, including maintaining redox balance, as well as regulating inflammatory processes arising in response to endogenous and exogenous factors reaching skin cells. Therefore, it is believed that dysregulation of eicosanoid levels may contribute to the development of skin diseases, such as psoriasis or atopic dermatitis, which in turn suggests that targeted control of the generation of specific eicosanoids may have diagnostic significance and beneficial therapeutic effects. This review is the first systemic and very detailed approach presenting both the causes and consequences of changes in phospholipid metabolism leading to the generation of eicosanoids, changes in the level of which result in specific metabolic disorders in skin cells leading to the development of various diseases. At the same time, existing literature data indicate that further detailed research is necessary to understand a clear relationship between changes in the level of specific eicosanoids and the pathomechanisms of specific skin diseases, as well as to develop an effective diagnostic and therapeutic approach.

The Octadecanoids: Synthesis and Bioactivity of 18-Carbon Oxygenated Fatty Acids in Mammals, Bacteria, and Fungi

The octadecanoids are a broad class of lipids consisting of the oxygenated products of 18-carbon fatty acids. Originally referring to production of the phytohormone jasmonic acid, the octadecanoid pathway has been expanded to include products of all 18-carbon fatty acids. Octadecanoids are formed biosynthetically in mammals via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) activity, as well as nonenzymatically by photo- and autoxidation mechanisms. While octadecanoids are well-known mediators in plants, their role in the regulation of mammalian biological processes has been generally neglected. However, there have been significant advancements in recognizing the importance of these compounds in mammals and their involvement in the mediation of inflammation, nociception, and cell proliferation, as well as in immuno- and tissue modulation, coagulation processes, hormone regulation, and skin barrier formation. More recently, the gut microbiome has been shown to be a significant source of octadecanoid biosynthesis, providing additional biosynthetic routes including hydratase activity (e.g., CLA-HY, FA-HY1, FA-HY2). In this review, we summarize the current field of octadecanoids, propose standardized nomenclature, provide details of octadecanoid preparation and measurement, summarize the phase-I metabolic pathway of octadecanoid formation in mammals, bacteria, and fungi, and describe their biological activity in relation to mammalian pathophysiology as well as their potential use as biomarkers of health and disease.

Creation of a novel zebrafish model with low DHA status to study the role of maternal nutrition during neurodevelopment

Docosahexaenoic acid (DHA), a dietary omega-3 fatty acid, is a major building block of brain cell membranes. Offspring rely on maternal DHA transfer to meet their neurodevelopmental needs, but DHA sources are lacking in the American diet. Low DHA status is linked to altered immune responses, white matter defects, impaired vision, and an increased risk of psychiatric disorders during development. However, the underlying cellular mechanisms involved are largely unknown, and advancements in the field have been limited by the existing tools and animal models. Zebrafish are an excellent model for studying neurodevelopmental mechanisms. Embryos undergo rapid external development and are optically transparent, enabling direct observation of individual cells and dynamic cell-cell interactions in a way that is not possible in rodents. Here, we create a novel DHA-deficient zebrafish model by 1) disrupting elovl2, a key gene in the DHA biosynthesis pathway, via CRISPR/Cas9 genome editing, and 2) feeding mothers a DHA-deficient diet. We show that low DHA status during development is associated with an abnormal eye phenotype and demonstrate that even morphologically normal siblings exhibit dysregulated vision and stress response gene pathways. Future work using our zebrafish model could reveal the cellular and molecular mechanisms by which low DHA status leads to neurodevelopmental abnormalities, and provide insight into maternal nutritional strategies that optimize infant brain health.

An Optimized Ex Vivo n-3 PUFA Supplementation Strategy for Primary Human Macrophages Shows That DHA Suppresses Prostaglandin E2 Formation

Evidence suggests beneficial effects of long-chain n-3 polyunsaturated fatty acids (PUFAs) in inflammatory diseases. However, the underlying mechanisms are still subject of research. For this purpose, we developed an ex vivo n-3 PUFA supplementation strategy. M2-like macrophages were supplemented for 2-3 days with 20-40 µM docosahexaenoic acid (DHA) during differentiation. Quality parameters include <3% oxylipins for PUFA-preparation, total fatty acids (FAs) <10 mM, and low oxylipins in plasma, n-3 PUFA <0.25 mM for the selection of donors of plasma as well as %n-6 in highly unsaturated fatty acids (HUFAs) ≥70% for donors of cells. Following supplementation, PUFA pattern of cells was shifted toward one described for blood and tissue from subjects with higher n-3 and lower n-6 PUFAs. This was accompanied by a decrease of arachidonic acid-derived oxylipins in a dose- and time-dependent manner in favor of n-3 PUFA ones. Stimulation with LPS resulted in decreased levels of pro-inflammatory prostaglandins in the DHA-supplemented cells, but no changes in cytokines. In vitro supplementation studies with n-3 PUFA need rigorous controls to exclude the background formation of oxylipins. By accounting for these possible confounders the described approach allows the mechanistic investigation of n-3 PUFAs in primary human immune cells, offering an alternative for intervention studies.

Oxylipin dynamics in dairy cows during clinical ketosis and after treatment with niacin and flunixin meglumine

Dairy cows with clinical ketosis (CK) exhibit metabolic changes, including intense adipose tissue (AT) lipolysis and systemic insulin resistance, that increase plasma BHB and free fatty acids (FFA). Cows with CK also have systemic inflammation, predisposing them to inflammatory and infectious diseases. This inflammatory process is modulated in part by oxidized fatty acids (oxylipins) that regulate all aspects of inflammation. Oxylipin profiles have been characterized in healthy periparturient cows, but their dynamics during CK are unknown. Clinical ketosis is an acute metabolic disease requiring clinical therapy, commonly including propylene glycol (PG) as a gluconeogenic agent. Recently, we showed that including lipolysis inhibitors such as niacin (NIA) and flunixin meglumine (FM) improved CK recovery. These drugs may modulate oxylipin biosynthesis by regulating the release of PUFA (oxylipin substrates) and cyclooxygenase activity. However, their impact on oxylipin profiles in cows with CK is unknown. The objective of this study was to determine the dynamics of specific linoleic and arachidonic acid-derived oxylipins during CK and following therapy with PG, NIA, and FM. Multiparous Jersey cows (n = 72; 7.1 DIM) with CK from a commercial dairy were sampled. Inclusion criteria were CK symptoms (lethargy, depressed appetite, and reduced rumen fill) and blood BHB ≥ 1.2 mmol/L. The CK cows (n = 24/treatment) were randomly assigned to one of the 3 treatments: (1) PG: 310 g orally once daily for 5 d, (2) PG + NIA (PGNIA): 24 g orally once daily for 3 d, (3) PG + NIA + FM (PGNIAFM): 1.1 mg/kg i.v. once daily for 3 d. Healthy control cows (HC; n = 24) matched by lactation and DIM (±2 d) were also included. Plasma oxylipins were quantified at enrollment and 7 d later using HPLC-MS/MS. At enrollment, CK had higher concentrations of arachidonic acid (ARA)-derived 5- and 20-HETE, 8,9-, 11,12-, and 14-15-DHET, and lower concentrations of linoleic acid (LA)-derived 12,13-EpOME, 13-oxoODE, 9,10- and 12,13-DiHOME. Integrated analysis of biological pathways and oxylipin profiles using Ingenuity Pathway Analysis revealed ARA metabolism as the top pathway activated during CK. By d 7, treatment with PGNIAFM restored plasma PUFA and oxylipins to profiles similar to HC. Ingenuity Pathway Analysis showed that PGNIAFM activated the zinc transporter SLC30A7, associated with reduced activation of the ARA pathway. Results indicate that higher FA availability during CK, driven in part by dysregulated lipolysis, increases the pool of substrates for oxylipin biosynthesis. These oxylipins may play a role in both metabolic dysregulation and restoring homeostasis during CK. Inhibiting lipolysis and cyclooxygenase activity with NIA and FM can alter ARA- and LA-derived oxylipin biosynthesis. These findings underscore the potential use of lipolysis inhibitors NIA and FM in CK therapeutics and highlight the importance of understanding oxylipin pathways in the pathogenesis of CK.

The platelet and plasma proteome and targeted lipidome in postpartum dairy cows with elevated systemic inflammation

Unregulated, systemic inflammation negatively impacts health and production in dairy cows. Soluble mediators and platelets have been studied for their expansive role in mediating inflammation. Our objectives were to compare the plasma oxylipin and endocannabinoid profiles, and the platelet and plasma proteomic profiles of healthy cows to cows experiencing elevated systemic inflammation as indicated by plasma haptoglobin (Hp) concentrations. Postpartum cows at 3 DIM with plasma Hp concentrations [Formula: see text] 0.50 g/L and no clinical disease were enrolled into the high-inflammation group (n = 8). Cows with plasma Hp concentrations [Formula: see text] 0.1 g/L and no clinical disease were enrolled into the low-inflammation group (n = 8). Targeted lipidomic analysis revealed differences in the plasma oxylipin and endocannabinoid profile between high- and low-inflammation cows. Cows in the high-inflammation group had increased plasma concentrations of the oxylipins 9(S)-HpOTrE, 9(S)-HOTrE, 13(S)-HpOTrE, and 9,10-EpOME, and the endocannabinoid anandamide. In-depth proteomic analysis of platelets between the high- and low-inflammation groups revealed significant differences in protein categories related to platelet granule release and cellular iron uptake. Proteomic outputs from plasma revealed 24 proteins to be different between high and low-inflammation groups, including proteins involved in autophagy and immune mediation. Together, our results indicate that cows experiencing an exacerbated systemic inflammatory response in the postpartum may have impaired disease resistance, and platelets could be contributors to their inflammatory state.

Effects of the Maximum Recommended Levels of Fumonisins in the EU on Oxylipin Profiles in the Liver and Brain of Chickens

This study aimed to assess the effects of a diet containing 20.8 mg FB1 + FB2/kg over four and nine days on oxylipin (OL) profiles in the liver and brain of chickens. A total of 96 OLs, derived from seven polyunsaturated fatty acids (PUFAs) via the cyclooxygenase (COX), lipoxygenase (LOX), cytochrome P450 (P450), and non-enzymatic pathways, were measured using HPLC-MS/MS. In the liver, a significant increase in epoxide P450-derived OLs was detected by day 4, with smaller but notable increases in COX- and LOX-derived OLs by day 9. These alterations were independent of whether the parent PUFA was ω6 or ω3. However, OLs derived from 18-carbon (C18) PUFAs, such as linoleic acid and alpha-linolenic acid, showed greater increases compared to those derived from C20 or C22 PUFAs. The diol/epoxide ratios in the liver decreased at four and nine days, suggesting that fumonisins did not induce an inflammatory response. In the brain, at four days, the most discriminative OLs were derived from ω3-PUFAs, including docosahexaenoic acid, docosapentaenoic acid, and alpha-linolenic acid, via the LOX pathway. By nine days, several OLs derived from arachidonic acid, spanning all enzymatic pathways, became discriminative. In general, the diol/epoxide ratios in the brain were decreased at 4 days and then returned to the initial levels. Taken together, these results show strong effects of fumonisins on OLs in the liver and brain that are both specific and distinct.

A Systematic Review: Assessment of the Metabolomic Profile and Anti-Nutritional Factors of Cannabis sativa as a Feed Additive for Ruminants

Background:Cannabis sativa is a high-value crop that can be cultivated for ruminant's feed and medicinal purposes. The demand for Cannabis and Cannabis products has increased since the beginning of 21st century. Objectives: The increase in the production cost of high-protein feeds such as lucerne has led to an urgent need to investigate alternative high-protein sources. Methods: Cannabis has been identified as an alternative to lucerne due to its high protein content. Results: However, the cultivation and uses of Cannabis and its by-products in South Africa is limited due to the strict legislation. The metabolites and nutritional value of Cannabis are influenced by growing conditions and soil type. Furthermore, the available literature has shown that Cannabis contains anti-nutritional factors that may affect feed intake or bioavailability and digestibility. Conclusions: Therefore, it is crucial to employ a processing method that can reduce anti-nutritional factors to promote the feed intake and growth rate of sheep. Fermentation, as a processing method, can reduce anti-nutritional factors found in Cannabis, which will make it a palatable alternative feed supplement for ruminants such as Dorper sheep. Overall, this review paper aimed to examine the available literature on the use of Cannabis as an alternative high-protein feed supplement for Dorper sheep in South Africa.

An integrated multi-omics analysis of the effects of the food processing-induced contaminant 2-monochloropropane-1,3-diol (2-MCPD) in rat heart

Many foods including edible oils contain 2-monochloropropane-1,3-diol (2-MCPD), a processing-induced chemical contaminant. Cardiotoxic effects have been shown to result from oral 2-MCPD exposure in rodents, but the underlying mechanisms of action remain poorly understood. We undertook a comprehensive multi-omics approach to assess changes at the transcriptomic, proteomic, and oxylipin levels in heart tissues from male F344 rats that were exposed to 0 or 40 mg/kg BW/day of 2-MCPD in the diet for 90 days, in a regulatory compliant rodent bioassay. Heart tissues were collected for RNA sequencing, quantitative PCR analysis, proteomic analysis via two-dimensional gel electrophoresis and mass spectrometry, and targeted lipidomic profiling by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Transcriptomic and proteomic data analyses revealed upregulation of immune/inflammatory response processes and downregulation of energy metabolism and cardiac structure and functions. Among differentially expressed gene-protein pairs, coronin-1A, a key leukocyte-regulating protein, emerged as markedly up-regulated. Oxylipin profiling highlighted a selective suppression of docosahexaenoic acid-derived metabolites, suggesting a disruption in cardioprotective lipid pathways. These findings suggest that 2-MCPD disrupts homeostasis through inflammatory activation and suppression of metabolic and cardiac function. This research provides insights into 2-MCPD's cardiotoxicity, emphasizing the need for further studies to support hazard characterization.

A Method to Estimate the Dietary α-Linolenic Acid Requirement Using Nonesterified DHA and Arachidonic Acid Oxylipins and Fatty Acids

BACKGROUND

The dietary requirement for α-linolenic acid (ALA) remains unclear, as evidenced by the absence of a Recommended Dietary Allowance (RDA) for this essential fatty acid (FA). In previous studies, we observed that the amount of dietary ALA required to maximize nonesterified (NE) DHA oxylipins appears to be higher than the amount required to maximize tissue esterified DHA, which have classically been used to estimate the ALA requirement. Further, we observed that dietary ALA reduces esterified arachidonic acid (ARA) and its NE oxylipins.

OBJECTIVES

Since NE oxylipins and FA mediate the biological activities of FA, we examined whether these DHA and ARA pools could be used to determine the dietary ALA requirement.

METHODS

Nine groups of 4-wk-old male Sprague-Dawley rats (n = 5) and 10 groups of male and female CD1 mice (n = 6) were provided 0.1-2.5 g ALA and 2 g of linoleic acid per 100 g of AIN93G-based diets. NE DHA and ARA and their oxylipins in serum, liver, kidney, and brain homogenates underwent solid phase extraction and were quantified by HPLC-MS/MS. Breakpoint analysis of transitions from increase to plateau was conducted using piecewise regression.

RESULTS

In response to increasing dietary ALA, NE DHA oxylipins, and DHA in serum, liver, and kidney (but not the brain) initially increased rapidly and then reached a plateau whereas ARA oxylipins and ARA tended to decrease before reaching a plateau. Thus, breakpoints were calculated for the ratios of DHA/ARA and hydroxy-DHA/hydroxy-ARA (DHAOH/ARAOH), which consisted of oxylipins synthesized via pathways common to both FA. In serum, liver, and kidney, the highest estimated breakpoint indicated an ALA requirement of ∼0.7 g/100 g diet (1.7% energy), approximately twice that of previous estimations.

CONCLUSIONS

This study supports the use of NE DHAOH/ARAOH or DHA/ARA as biochemical indicators of the ALA requirement. Applying this method in rats and mice indicates that the requirement is higher than previously estimated using esterified DHA alone.

Deducing formation routes of oxylipins by quantitative multiple heart-cutting achiral-chiral 2D-LC-MS

Several oxylipins are regulators of inflammation. They are formed by enzymes such as lipoxygenases or cyclooxygenases, but also stereorandomly by autoxidation. Reversed-phase liquid chromatography-tandem-mass-spectrometry (LC-MS/MS) methods for oxylipin quantification do not separate enantiomers. Here, we combine sensitive and selective oxylipin analysis with chiral separation using two-dimensional (2D)-LC-MS/MS. By multiple heart-cutting, the oxylipin peaks are transferred onto a chiral column. 45 enantiomeric pairs of (di-)hydroxy-fatty acids are separated with full gradient elution within 1.80 min, yielding lower limits of quantification <1 pg on the column. Concentrations, as well as enantiomeric fractions of oxylipins, can be determined, even at low concentrations or at high enantiomeric excess of one isomer. The developed achiral-chiral multiple heart-cutting 2D-LC-MS/MS method offers unprecedented selectivity, enabling a better understanding of the formation routes of these lipid mediators. This is demonstrated by distinguishing the formation of hydroxy-fatty acids by (acetylated) cyclooxygenase-2 and radical-mediated autoxidation. Applying the method to human M2-like macrophages, we show that the so-called specialized pro-resolving mediators (SPM) 5,15-DiHEPE and 7,17-DiHDHA as well as 5,15-DiHETE were present as (S,S)-enantiomers, supporting their enzymatic formation. In contrast, at least eight isomers (including protectin DX but not neutroprotectin D1) of 10,17-DiHDHA are present in immune cells, indicating formation by autoxidation. In the human plasma of healthy individuals, none of these dihydroxy-fatty acids are present. However, we demonstrate that all four isomers quickly form via autoxidation if the samples are stored improperly. Dihydroxy-FA should only be reported as SPM, such as resolvin D5 or resolvin E4, if an enantioselective analysis as described here has been carried out.

Omega-3 Fatty Acids and Traumatic Injury in the Adult and Immature Brain

Background/Objectives: Traumatic brain injury (TBI) can lead to substantial disability and health loss. Despite its importance and impact worldwide, no treatment options are currently available to help protect or preserve brain structure and function following injury. In this review, we discuss the potential benefits of using omega-3 polyunsaturated fatty acids (O3 PUFAs) as therapeutic agents in the context of TBI in the paediatric and adult populations. Methods: Preclinical and clinical research reports investigating the effects of O3 PUFA-based interventions on the consequences of TBI were retrieved and reviewed, and the evidence presented and discussed. Results: A range of animal models of TBI, types of injury, and O3 PUFA dosing regimens and administration protocols have been used in different strategies to investigate the effects of O3 PUFAs in TBI. Most evidence comes from preclinical studies, with limited clinical data available thus far. Overall, research indicates that high O3 PUFA levels help lessen the harmful effects of TBI by reducing tissue damage and cell loss, decreasing associated neuroinflammation and the immune response, which in turn moderates the severity of the associated neurological dysfunction. Conclusions: Data from the studies reviewed here indicate that O3 PUFAs could substantially alleviate the impact of traumatic injuries in the central nervous system, protect structure and help restore function in both the immature and adult brains.

Oxylipins Derived from PUFAs in Cardiometabolic Diseases: Mechanism of Actions and Possible Nutritional Interactions

Oxylipins are oxidized fatty acids, both saturated and unsaturated, formed through pathways that involve singlet oxygen or dioxygen-mediated oxygenation reactions and are primarily produced by enzyme families such as cyclooxygenases, lipoxygenases, and cytochrome P450. These lipid-based complex bioactive molecules are pivotal signal mediators, acting in a hormone-like manner in the pathophysiology of numerous diseases, especially cardiometabolic diseases via modulating plenty of mechanisms. It has been reported that omega-6 and omega-3 oxylipins are important novel biomarkers of cardiometabolic diseases. Moreover, collected literature has noted that diet and dietary components, especially fatty acids, can modulate these oxygenated lipid products since they are mainly derived from dietary omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) or linoleic acid and α-linolenic by elongation and desaturation pathways. This comprehensive review aims to examine their correlations to cardiometabolic diseases and how diets modulate oxylipins. Also, some aspects of developing new biomarkers and therapeutical utilization are detailed in this review.

Cardiac oxylipin perturbances in response to 2-monochloropropane-1,3-diol exposure are ameliorated by dietary adequacy of the essential n-3 fatty acid, α-linolenic acid

2-Monochloropropane-1,3-diol (2-MCPD) is a food contaminant with demonstrated cardiotoxicity in rats. This adverse effect was previously associated with lower anti-inflammatory docosahexaenoic acid (DHA)-derived cardiac oxylipins in F344 rats. This previous study utilized corn oil as the dietary lipid; we therefore investigated whether deficient (0.07 g/100 g diet) or adequate (0.5 g/100 g diet) dietary α-linolenic acid (ALA), the essential n-3 polyunsaturated fatty acid (PUFA), alters the oxylipin response in heart, liver, kidney, and serum of Sprague-Dawley rats exposed to 50 mg 2-MCPD/kg BW/day. ALA increased n-3 oxylipins in all tissues, reflecting greater n-3 PUFA substrate availability. In the heart, 2-MCPD increased cyclooxygenase-derived arachidonic acid oxylipins, conducive to inflammation. Adequate dietary ALA revealed 2-MCPD-induced reductions of anti-inflammatory cardiac DHA-derived oxylipins; these were not apparent in the ALA-deficient diet as these n-3 PUFA oxylipins were already reduced. Conversely, 2-MCPD increased cardiac 13-hydroxy-octadecatrienoic acid-γ (13-HOTrE-γ) levels with deficient, but not adequate, ALA diets. Multi-tissue analysis identified 13-HOTrE-γ as a marker of 2-MCPD exposure. Our study contributes to the weight-of-evidence of 2-MCPD toxicity, confirms the functional and indicative roles of oxylipins in the heart, and demonstrates that live bioassays determining chemical health hazards should use adequate n-3 PUFA diets.

Plant extracts and omega-3 supplementation modulate hippocampal oxylipin profile in response to LPS-induced neuroinflammation

OBJECTIVE AND DESIGN

Neuroinflammation is a protective mechanism but can become harmful if chronic and/or unregulated, leading to neuronal damage and cognitive alterations. Limiting inflammation and promoting resolution could be achieved with nutrients such as grapes and blueberries polyphenols, saffron carotenoids, and omega-3, which have anti-inflammatory and proresolutive properties.

METHODS

This study explored the impact of 18-day supplementation with plant extracts (grape, blueberry and saffron), omega-3 or both (mix) on neuroinflammation induced by lipopolysaccharide (LPS, 250 µg/kg) in 149 mice at different time points post-LPS treatment (30 min, 2 h, 6 h). Inflammatory, oxidative and neuroprotective gene expression; oxylipin quantification; and fatty acid composition were analyzed at each time point. PCA analysis was performed with all these biomarkers.

RESULTS

Mix supplementation induced changes in the resolution of inflammation. In fact, the production of proinflammatory mediators in the hippocampus started earlier in the supplemented group than in the LPS group. Pro-resolving mediators were also found in higher quantities in supplemented mice. These changes were associated with increased hippocampal antioxidant status at 6 h post-LPS.

CONCLUSIONS

These findings suggest that such dietary interventions with plant extracts, and omega-3 could be beneficial in preventing neuroinflammation and, consequently, age-related cognitive decline. Further research is needed to explore the effects of these supplements on chronic inflammation in the context of aging.

Integrated untargeted/targeted metabolomics identifies a putative oxylipin signature in patients with atrial fibrillation and coronary heart disease

Background and Objective

Atrial fibrillation (AF) and coronary heart disease (CHD) are closely related to metabolic dysregulation. However, the metabolic characteristics of AF patients with concomitant CHD remain unclear. The aims of this study were to elucidate the metabolic profiles of patients with AF and CHD to seek new therapeutic targets and related factors of AF combined with CHD.

Methods

Untargeted metabolomics and targeted oxylipins profiling were performed to characterize the serum metabolome landscape of patients with AF, CHD, and AF comorbid CHD.

Results

The serum metabolic fingerprints of patients with AF comorbid CHD were significantly differentiated from normal controls (NC) and individuals with AF or CHD alone, and the differentiated metabolites dominated by a variety of lipid alterations in the phospholipid and fatty acid metabolism. Furthermore, the targeted profiles of oxylipins demonstrated that the levels of arachidonic acid derivatives including prostaglandins, leukotrienes, hydroxy-docosahexaenoic acids, hydroxy-eicostetraenoic acids and hydroxy-eicosatrienoic acids in patients with AF and CHD were significantly different from those in the NC, AF, and CHD groups. Several prostaglandins were positively associated with echocardiographic indicators of myocardial remodeling.

Conclusions

This study updates metabolic insights of AF and CHD and provides potential therapeutic targets for preventing or treating AF comorbid CHD.

Plant and algal lipidomes: Analysis, composition, and their societal significance

Plants and algae play a crucial role in the earth's ecosystems. Through photosynthesis they convert light energy into chemical energy, capture CO2 and produce oxygen and energy-rich organic compounds. Photosynthetic organisms are primary producers and synthesize the essential omega 3 and omega 6 fatty acids. They have also unique and highly diverse complex lipids, such as glycolipids, phospholipids, triglycerides, sphingolipids and phytosterols, with nutritional and health benefits. Plant and algal lipids are useful in food, feed, nutraceutical, cosmeceutical and pharmaceutical industries but also for green chemistry and bioenergy. The analysis of plant and algal lipidomes represents a significant challenge due to the intricate and diverse nature of their composition, as well as their plasticity under changing environmental conditions. Optimization of analytical tools is crucial for an in-depth exploration of the lipidome of plants and algae. This review highlights how lipidomics analytical tools can be used to establish a complete mapping of plant and algal lipidomes. Acquiring this knowledge will pave the way for the use of plants and algae as sources of tailored lipids for both industrial and environmental applications. This aligns with the main challenges for society, upholding the natural resources of our planet and respecting their limits.

Gestational PFAS exposure and newborn size: The modifying effect of cord blood fatty acids

Per- and polyfluoroalkyl substances (PFASs) can disrupt lipid metabolism, and changes in cord blood fatty acid composition have been observed in small newborns. Emerging evidence suggests that exposure to PFASs during pregnancy is linked to decreased newborn size, although the evidence is not consistent. The modifying effect of fatty acids on the associations of gestational PFAS exposure with newborn size is still unknown. Here we show that the nutritional status of the fetus, as indicated by the level of fatty acids in the cord blood, mitigates the adverse effects of gestational PFAS exposure on the size of the newborn. Our study confirms the adverse developmental effects of PFASs and identifies emerging short-chain PFASs as the primary drivers of reduced newborn size, despite their lower exposure burden compared to legacy PFASs. Additionally, we find the protective role of cord blood fatty acids, suggesting potential strategies for mitigating the detrimental effects of emerging environmental exposures on human health. Our findings provide new evidence of the potential toxicity of emerging PFASs and call for further toxicity evaluations of these pollutants for regulatory purposes. Future studies should consider the complex interaction between exposure and nutrition within the human body, particularly during the first thousand days of life, to promote lifelong health.

Bioactive lipids are altered in the heart, kidney, and serum of male and female F344 rats sub-chronically exposed to dietary 2-MCPD

Chloropropanols have been identified as processing-induced food contaminants that occur as by-products of the manufacturing of refined food oils and hydrolyzed vegetable protein. There has been a paucity of research on the 2-monochloropropane-1,3-diol (2-MCPD) isomer, thus forming a data gap for regulatory risk assessment. Previous studies suggest 2-MCPD causes adverse cardiotoxic, nephrotoxic, and myotoxic effects, but were inconclusive for hazard identification; thus a dose-response OECD TG-408-compliant study was conducted by Health Canada. Our study profiled the effects of 2-MCPD on oxylipins and oxidized phosphatidylcholines, using HPLC-MS/MS, in heart, kidney, serum, and skeletal muscle of male and female F344 rats orally exposed to 2-MCPD (40 mg/kg BW/d) for 90 days. Cardiac n-3 polyunsaturated fatty acid-derived oxylipins, particularly DHA-derived oxylipins, were lower with 2-MCPD exposure, coincident with cardiac lesions. Lipoxygenase-derived oxylipins were decreased in the serum with a greater effect in the male 2-MCPD treatment group. Few oxylipin alterations were seen in the kidney and there was an absence of alterations in the tibialis anterior. Oxidized phosphatidylcholines and isoprostanes were not altered in this study, indicating that oxidative stress was not elevated by 2-MCPD. These findings add to the weight of the evidence for 2-MCPD toxicity and support the use of serum oxylipins as potential biomarkers of 2-MCPD exposure.

Pharmacometabolomics Approach to Explore Pharmacokinetic Variation and Clinical Characteristics of a Single Dose of Desvenlafaxine in Healthy Volunteers

This study investigated the effects of a single dose of desvenlafaxine via oral administration on the pharmacokinetic parameters and clinical and laboratory characteristics in healthy volunteers using a pharmacometabolomics approach. In order to optimize desvenlafaxine's therapeutic use and minimize potential adverse effects, this knowledge is essential. Methods: Thirty-five healthy volunteers were enrolled after a health trial and received a single dose of desvenlafaxine (Pristiq®, 100 mg). First, liquid chromatography coupled to tandem mass spectrometry was used to determine the main pharmacokinetic parameters. Next, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used to identify plasma metabolites with different relative abundances in the metabolome at pre-dose and when the desvenlafaxine peak plasma concentration was reached (pre-dose vs. post-dose). Results: Correlations were observed between metabolomic profiles, such as tyrosine, sphingosine 1-phosphate, and pharmacokinetic parameters, as well as acetoacetic acid and uridine diphosphate glucose associated with clinical characteristics. Our findings suggest that desvenlafaxine may have a broader effect than previously thought by acting on the proteins responsible for the transport of various molecules at the cellular level, such as the solute carrier SLC and adenosine triphosphate synthase binding cassette ABC transporters. Both of these molecules have been associated with PK parameters and adverse events in our study. Conclusions: This altered transporter activity may be related to the reported side effects of desvenlafaxine, such as changes in blood pressure and liver function. This finding may be part of the explanation as to why people respond differently to the drug.

Disease response in rheumatoid arthritis across four biologic therapies associates with improvement in paraoxonase-1 activity and oxylipins

OBJECTIVE

Paraoxonase-1 (PON1) is a high-density lipoprotein (HDL)-associated enzyme, that has been implicated as a biomarker of cardiovascular risk in patients with rheumatoid arthritis (RA). We aimed to investigate how different biologic therapies affect levels of PON1 and oxylipins.

METHODS

1213 adult patients with RA in the Comparative Effectiveness Registry to study Therapies for Arthritis and Inflammatory CoNditions cohort study with moderate-to-high disease activity (Clinical Disease Activity Index (CDAI) >10) who initiated a new biologic (tocilizumab (TCZ), n=296; abatacept, n=374; tumour necrosis factor inhibitors, n=427; rituximab, n=116) were followed prospectively with serum specimens analysed for PON1 activity by arylesterase (ARYL), lactonase (LAC) and PON assays at baseline and after 6 months of biologic therapy. A targeted panel of oxylipins was evaluated by liquid chromatography-mass spectrometry/mass spectrometry in a subset of patients with the lowest and highest 6-month Disease Activity Score 28 (DAS28)-C reactive protein (CRP) responses in each treatment group.

RESULTS

PON1 activity generally increased in the entire cohort after 6 months of new biologic therapy, showing the greatest, most consistent increases in the TCZ group. Increases in all three PON1 domains associated with significant decreases in disease activity in DAS28-CRP/CDAI (p<0.05), and increases in LAC/ARYL were significantly associated with the American College of Rheumatology 20/50/70 responses (OR (95% CI) of 1.12 (1.04, 1.22) and 1.13 (1.04, 1.23), p<0.01, respectively), after controlling for other RA disease characteristics. Some oxylipins, including 12-hydroxyeicosatetraenoic acid correlated with RA disease activity measures.

CONCLUSION

Improvement in disease activity across four classes of biologics is associated with enhanced PON1 activity, which has significant implications for cardiovascular safety.

Mass spectrometry unveils heat-induced changes in yolk oxylipins and key lipid molecules during home cooking

INTRODUCTION

Oxylipins, as a widespread class of metabolic markers following oxidative stress, and several studies have reported dietary regulation of lipid metabolism. However, there is a lack of investigation of dietary oxylipins, especially cooking-induced changes in food lipid oxidation.

OBJECTIVES

Investigated the effects of cooking methods and lipid profiles on polyunsaturated fatty acids derived oxylipins generation within egg yolks.

METHODS

The lipid profile of egg yolk was determined by UPLC-QTOF-MS/MS, oxylipins were detected by HPLC-QTRAP-MS/MS, while the total fatty acid content was quantified by GC-FID. Random Forest (RF) and Partial Least Squares (PLS) regression models were employed to explore the association between oxidized lipids and key lipid species.

RESULTS

Heating reduced egg yolk docosahexaenoic acid (DHA) content, and no consistent trends for arachidonic acid (AA), linoleic acid (LA), and linolenic acid (ALA). Yolk lipid composition affected triacylglycerol (TG), phosphatidylethanolamine (PE), and LA-monoepoxide contents after cooking. 9- and 13-HODE (hydroxyoctadecadienoic acid), 9,10,13-TriHOME (trihydroxyoctadecenoic acid), 9,10- and 12,13-EpOME (epoxyoctadecenoic acid), 9,10- and 12,13-DiHOME (dihydroxyoctadecenoic acid), 5-HETE (hydroxyeicosatetraenoic acid), and 4-HDHA (hydroxydocosahexaenoic acid) were the prevalent oxylipins with high concentrations, accounting for 1.08 %-29.58 % of the total content of 29 oxylipins. Steaming resulted in a 1.9-fold increase in oxylipin concentrations in yolks compared to raw yolks, and boiling with or without shells (poaching) resulted in a 1.30- to 1.76-fold increase in oxylipin concentrations. In contrast, pan-fried yolks exhibited the lowest and least variable levels of total oxylipins, while still retaining some epoxides, including epoxyeicosatrienoic acid (EET) and EpOME. Utilizing big data analysis, we mapped the oxylipin network in both ordinary and DHA-enriched egg yolks, revealing a strong correlation between cooking-induced oxylipin production and variations in 24 lipid species.

CONCLUSION

Revealed the potential mechanisms and key lipid molecules for heating-induced oxylipin production of yolk through lipidomics and big data analysis.

Translocon Subunits of the COP9 Signalosome Complex Are a Central Hub for Regulating Multiple Photoresponsive Processes and Autophagic Flux in Magnaporthe oryzae

Photodependent processes, including circadian rhythm, autophagy, ubiquitination, neddylation/deneddylation, and metabolite biosynthesis, profoundly influence microbial pathogenesis. Although a photomorphogenesis signalosome (COP9/CSN) has been identified, the mechanism by which this large complex contributes to the pathophysiological processes in filamentous fungi remains unclear. Here, we identified eight CSN complex subunits in the rice blast fungus Magnaporthe oryzae and functionally characterized the translocon subunits containing a nuclear export or localization signal (NES/NLS). Targeted gene replacement of these CSN subunits, including MoCSN3, MoCSN5, MoCSN6, MoCSN7, and MoCSN12, attenuated vegetative growth and conidiation and rendered the deletion strains nonpathogenic. MoCSN7 deletion significantly suppressed arachidonic acid catabolism, and compromised cell wall integrity in M. oryzae. Surprisingly, we also discovered that MoCSN subunits, particularly MoCsn7, are required for the cAMP-dependent regulation of autophagic flux. Therefore, MoCSN significantly contributes to morphological, physiological, and pathogenic differentiation in M. oryzae by fostering cross-talk between multiple pathways.

Impact of adding eicosapentaenoic and docosahexaenoic acid-rich fish oil in sow and piglet diets on blood oxylipins and immune indicators of weaned piglets

Weaning is a decisive event in piglets' life. This study aimed to evaluate whether the inclusion of fish oil, rich in eicosapentaenoic and docosahexaenoic acids (EPA and DHA), in sow and piglet diets, increased the concentration of anti-inflammatory molecules in the blood of weaned piglets and whether the effect was dependent on the pigs being born with either low or a high birth BW (bBW). Thirty-six sows in four consecutive batches were randomly distributed between a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or a n-3 long-chain fatty acid diet (LCFA; totally or half replacing animal fat by fish oil during gestation and lactation, respectively) from service until weaning (ca. 28 days). At birth, the two lightest (LBW) and the two heaviest (HBW) piglets in each litter were identified and, at weaning, grouped in pens by pairs prioritising their bBW. Pens were further distributed into a control (30 g/kg animal fat) or n-3 LCFA diet (totally replacing animal fat by fish oil) for 28 days. At the end of the trial, blood was collected from piglets in the first batch (n = 48). Serum fatty acids (FAs) were quantified by GC, plasma oxylipins by ultra-HPLC-MS, and plasma immune indicators by ELISA. An interaction between piglet diet and bBW for average daily gain (P = 0.020) and average daily feed intake (P = 0.014) during the whole postweaning indicated that dietary n-3 LCFA-promoted LBW piglets to have a similar growth and intake than HBW piglets reaching 1.5 kg average BW more at the end of the postweaning period than LBW control piglets. Fish oil in piglet diets also increased the concentrations of total n-3 FA, EPA and DHA (all P < 0.001), their resultant oxylipins, particularly their hydroxy derivatives from lipoxygenase enzymatic pathway (all P < 0.001) and tended to increase immunoglobulin M (P = 0.067) in blood. Regarding the bBW category, LBW piglets tend to increase tumour necrosis factor α in plasma (P = 0.083) compared to HBW. It is concluded that fish oil in postweaning diets could enhance the daily gain and feed intake of LBW piglets, increasing the concentration of serum n-3 FAs and their derived oxylipins in plasma.

Physiological changes associated with aging: Identification of novel biomarkers for frailty syndrome in women

This study explores the physiological changes associated with aging that lead to frailty syndrome, characterized by reduced vitality and degeneration across multiple bodily systems, increasing susceptibility to various pathologies. While established scales like the Fried Phenotype and Frailty Trait Scale (FTS) are commonly used for assessing frailty, incorporating biomarkers is crucial for accurate diagnosis and prognosis. Our research examines plasma oxylipin levels in frail elderly individuals to identify novel biomarkers. Diagnostic criteria for frailty included assessments using the Fried Phenotype and FTS-5, with blood samples collected from 71 elderly participants (50 women and 21 men) with mean ages of 73.6 ± 5.9 and 76.2 ± 6.2 years, respectively. Women exhibited elevated platelet counts (p-value 0.0035). The significant differences in oxylipin concentrations associated with the Fried Phenotype were particularly noteworthy, predominantly observed in women. Specifically, in women, decreased grip strength (<15 kg) and slow gait speed (<0.8 m/s) correlated with increased levels of thromboxane B2 (TxB2) and 7-HDoHE (p-values 0.0404, 0.0300, 0.0033, and 0.0033, respectively). Additionally, elevated 7-HDoHE levels correlated with a BMI exceeding 28 kg/m2 (p-value 0.0123) and Physical Activity Scale for the Elderly (PASE) scores surpassing 5 points (p-value 0.0134) in women. In summary, our findings emphasize that frail older individuals, particularly women, exhibit higher levels of TxB2 and 7-HDoHE compared to their non-frail counterparts, aligning with established frailty classification and scale parameters, suggesting their potential as indicative biomarkers.

Acetylsalicylic acid inhibition of the lipoxygenase pathway: Implications for HIV prevention

BACKGROUND

1.5 million new HIV infections occurred in 2021, suggesting new prevention methods are needed. Inflammation increases the risk for HIV acquisition by attracting HIV target cells to the female genital tract (FGT). In a pilot study, acetylsalicylic acid (ASA/Aspirin) decreased the proportion of FGT HIV target cells by 35 %. However, the mechanism remains unknown.

METHODS

Women from Nairobi, Kenya took low-dose ASA (81 mg) daily for 6-weeks. Free oxylipins in the plasma were quantified by high-performance liquid chromatography-tandem mass spectroscopy.

RESULTS

Oxylipins from 9 fatty acid substrates were detected, with more than one analyte from 4 substrates reduced post-ASA. Summary analysis found ASA downregulated cyclooxygenase and lipoxygenase but not cytochrome P450 activity with a lower n-6/n-3 oxylipin profile, reflecting reduced inflammation post-ASA.

CONCLUSIONS

Inflammation is associated with increased lipoxygenase activity and HIV risk. Our data suggests ASA reduces inflammation through downregulation of oxylipins. Understanding how ASA reduces inflammation may lead to novel HIV prevention approaches.

Plasma n6 polyunsaturated fatty acid levels and risk for total and cause-specific mortality: A prospective observational study from the UK Biobank

BACKGROUND

The potential role of n-6 PUFAs in major health outcomes remains controversial.

OBJECTIVES

To examine the relationship between the major plasma n6 PUFA, linoleic acid (LA), as well as the non-LA n6 PUFAs, and total and cause-specific mortality.

METHODS

This was a prospective, observational, biomarker-based study in the UK Biobank. Individuals with complete information on baseline demographic, covariate and plasma PUFA levels (percent ot total fatty acids) and mortality outcomes were included (n=257,925). Multivariable-adjusted, Cox-proportional hazards models were used to predict risk of death from all-causes, and from cardiovascular disease (CVD), cancer, and other causes as a function of plasma LA and non-LA n6 levels, both continuously and by PUFA quintile (Q).

RESULTS

Comparing LA Q5 to Q1, the hazard ratio (HR, 95% CI) for total mortality was 0.80 (0.76, 0.84; p<0.001), and this was similar for all three cause-specific death categories. On the other hand, mortality HR for non-LA n6 was 1.12 (1.08,1.17; p<0.001), and this was primarily due to increased risk for non-CVD, noncancer deaths [HR 1.29 (1.19,1.40; p<0.001)]. Exploratory analyses among the eight next most common other causes of death suggested that both the decreased risk associated with higher LA and the increased risk associated with non-LA n6 were confined to deaths from respiratory and digestive diseases.

CONCLUSIONS

These findings highlight the profound differences in mortality risk related to LA and non-LA n6 PUFA levels and underscore the inappropriateness of treating n-6 PUFAs as a homogenous class with respect to health outcomes. They also support recommendations to maintain (if not increase) current LA intakes.