Eicosatetraenoic Acid Research Articles

Abstract 4134926: Association of Eicosanoid Metabolites with Body Mass Index

Introduction: The specific molecular pathways from obesity to inflammation to cardiovascular disease remain unclear. Eicosanoids are a unique class of bioactive lipids that govern the upstream initiation of pro- and anti-inflammatory activity. Objective: We leveraged a novel lipidomic platform to quantify > 800 eicosanoid metabolites and examined their association with body mass index (BMI). Methods: We studied Multi-Ethnic Study of Atherosclerosis (MESA) participants with available samples for eicosanoid analysis. Eicosanoids and related metabolites were assessed using a directed, non-targeted mass spectrometry-based platform. We examined the cross-sectional association of eicosanoid metabolites with BMI using multivariable linear regression models. Analyses were considered significant at FDR q-value <0.01. Results: A total of 5101 individuals (age 63 ± 10 years; 53% women, 60% non-Whites) were included. The mean BMI was 28.3 ± 5.1 kg/m2. Of 811 eicosanoids analyzed, 255 showed a significant association with BMI (see Figure for putative metabolite identities; FDR q-value <0.01 for all). Derivatives of docosahexaenoic acid (DHA; 19,20 DiHDPA, β = - 0.206, standard error [SE] = 0.013) and eicosatetraenoic acid (11(S) HEPE, β = - 0.180, SE = 0.014) were associated with lower BMI. Linoleic acid derivatives (12,13 diHOME, an exercise-induced lipokine) had a similar association. Conversely, derivatives of linoleic acid (13-oxoODE, β = 0.241, SE = 0.01) and arachidonic acid (11-HETE, β = 0.236, SE = 0.017) were associated with higher BMI. Other derivatives of linoleic acid (15 (S) HETrE) and prostaglandin (11b PGF2α) were also associated with higher BMI. Conclusions: We found that specific eicosanoid metabolites, including DHA and linoleic acid derivatives with known anti-inflammatory, atheroprotective, and beneficial metabolic effects (e.g., 19,20 DiHDPA; 12,13 diHOME), were associated with lower BMI. By contrast, specific arachidonic acid and prostaglandin derivatives with known pro-inflammatory and adverse CV effects (e.g. oxylipin 11-HETE; PGF2α; 13-oxoODE) were associated with higher BMI. These findings further the understanding of specific inflammatory pathways underlying the development of obesity-related CVD.

Invasive Seaweed Rugulopteryx okamurae: A Potential Source of Bioactive Compounds with Antioxidant Activity

Rugulopteryx okamurae (RO) is a species of brown seaweed that has invaded several shorelines worldwide, including the Spanish Mediterranean and the Strait of Gibraltar coasts, causing serious environmental and economic problems. This work aimed to characterize the bioactive composition of RO. A high content of carbohydrates (58.7 ± 2.6 wt%), fats (17.1 ± 0.4 wt%), and ashes (14.3 ± 0.2 wt%) were found, together with lower protein content (5.5 ± 1.8 wt%). Holocellulose was the most abundant polysaccharide fraction (49.2 ± 1.3 wt%), showing 43.4 ± 2.0 wt% of cellulose and 5.8 ± 0.7 wt% of hemicellulose, followed by lignin (18.9 ± 2.5 wt%). The monosaccharides composition showed a high level of glucose (13.2 ± 1 wt%) and glucuronic acid (9.3 ± 0.5 wt%). RO contained high levels of essential nutrients (Ca, K, Na, S, Mg), trace minerals (Mn, Mo, Se, and Cu), and some toxic heavy metals (Ni, Cd, As). The main fatty acid present in RO was palmitic acid (C16:0, 30.8 ± 3.0 mg/100 g), followed by myristic acid (C14:0, 19.3 ± 2.4 mg/100 g) and eicosatetraenoic acid (C20:4, 19.2 ± 1.3 mg/100 g). The extract obtained by microwave-assisted extraction (MAE) presented significant contents of polyphenols (2.7 ± 0.2 mg GAE/g) and antioxidant activity (3.0 ± 0.4 mg TE/g DPPH, 4.5 ± 0.3 mg TE/g ABTS, 4.7 ± 0.3 mg TE/g FRAP). Six main polyphenols were identified by HPLC-MS/MS, showing higher contents of gallic acid (20.7 ± 1.5 mg/g) and chlorogenic acid (9.7 ± 0.5 mg/g). These results highlight the possibilities offered in the valorization of RO to obtain bioactive compounds with antioxidant performance in several applications.

Association between Serum Fatty Acids Profile and MetScore in Women with Severe Obesity

Background: Metabolic syndrome (MetS) is a set of conditions associated with an increased cardiovascular risk. Several serum fatty acids (FAs) seem to play an essential role in the development of cardiometabolic diseases and mortality. Thus, it is imperative to explore the impact of FAs on MetS parameters, using an early MetS screening tool such as MetScore, which is readily available in clinical practice. Aim: The aim of this study was to assess the potential correlation between serum FAs and cardiovascular risk using a MetScore. Methods: This cross-sectional study involved 41 women with severe obesity. The MetScore was calculated, and participants were categorized into high- and low-cardiovascular-risk groups based on the median MetScore value. Gas chromatography was used to quantify serum FAs. Generalized Linear Models were used to compare group means. The association was assessed through simple logistic regression, and an adjusted logistic regression was conducted to validate the association between Metscore and serum FAs. Results: The high-cardiovascular-risk group exhibited elevated values of HOMA-IR, palmitic, oleic, cis-vaccenic, and monounsaturated fatty acids, as well as the SCD-18C, indicating a heightened cardiovascular risk. Conversely, HDL-c, QUICK, gamma-linolenic, and eicosatetraenoic fatty acids showed lower values compared to the low-risk group. Conclusions: Women with severe obesity and high cardiovascular risk have lower values of some omega-3 and omega-6 FAs, considered cardioprotective and anti-inflammatory, and have higher lipogenic activity and FAs, correlated with high cardiovascular risk. These findings emphasize the need to address lipid metabolism in this population as a therapeutic target to reduce cardiovascular risk. Future research should explore clinical interventions that modulate fatty acid metabolism to mitigate cardiometabolic complications.

FGF21 modulates immunometabolic homeostasis via the ALOX15/15-HETE axis in early liver graft injury

Fibroblast growth factor 21 (FGF21) is essential for modulating hepatic homeostasis, but the impact of FGF21 on liver graft injury remains uncertain. Here, we show that high FGF21 levels in liver graft and serum are associated with improved graft function and survival in liver transplantation (LT) recipients. FGF21 deficiency aggravates early graft injury and activates arachidonic acid metabolism and regional inflammation in male mouse models of hepatic ischemia/reperfusion (I/R) injury and orthotopic LT. Mechanistically, FGF21 deficiency results in abnormal activation of the arachidonate 15-lipoxygenase (ALOX15)/15-hydroxy eicosatetraenoic acid (15-HETE) pathway, which triggers a cascade of innate immunity-dominated pro-inflammatory responses in grafts. Notably, the modulating role of FGF21/ALOX15/15-HETE pathway is more significant in steatotic livers. In contrast, pharmacological administration of recombinant FGF21 effectively protects against hepatic I/R injury. Overall, our study reveals the regulatory mechanism of FGF21 and offers insights into its potential clinical application in early liver graft injury after LT.

In vitro gastrointestinal digestibility and lipid oxidation of fish oil-in-water emulsions: Influence of different EPA/DHA ratios

The long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs) eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA) are known to play roles in supporting human health, primarily by reducing inflammation and promoting its resolution. In this study, the impacts of EPA/DHA ratios (5.13/1, 2.45/1,1.34/1) on lipid oxidation and digestion behaviors were explored using an in vitro digestion model. Emulsions were characterzied by droplet size, zeta-potential as well as microstructure. Additionally, the release of free fatty acids (FFAs), lipid hydroperoxides (LPO) and thiobarbituric acid reactive substance (TBARS) were also investigaed throughout simulated digestion phases. Notably, for all EPA/DHA ratios, from saliva fluid to gastric fluid, droplet size was slightly changed, accompanied by a significant decrease in absolute zeta-potential, followed by an increase in both parameters after intestinal digestion. Emulsions with the lowest ratio of EPA/DHA (i.e., 1.34/1) exhibited lower FFA release compared to those with higher ratios (i.e., 5.13/1 and 2.45/1). Conversely, the lowest EPA/DHA ratio increased oxidation during the intestinal phase, as indicated by elevated LPO and TBARS levels. This study clearly suggests that EPA/DHA ratios influence the oxidative stability of fish oil emulisions during digestion and provides useful information to formulate fish oil supplementation that improves in vivo oxidative status.

Metabolomic Profiles in Jamaican Children With and Without Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with a wide range of behavioral and cognitive impairments. While genetic and environmental factors are known to contribute to its etiology, metabolic perturbations associated with ASD, which can potentially connect genetic and environmental factors, remain poorly understood. Therefore, we conducted a metabolomic case-control study and performed a comprehensive analysis to identify significant alterations in metabolite profiles between children with ASD and typically developing (TD) controls in order to identify specific metabolites that may serve as biomarkers for the disorder. We conducted metabolomic profiling on plasma samples from participants in the second phase of Epidemiological Research on Autism in Jamaica, an age and sex-matched cohort of 200 children with ASD and 200 TD controls (2-8years old). Using high-throughput liquid chromatography-mass spectrometry techniques, we performed a targeted metabolite analysis, encompassing amino acids, lipids, carbohydrates, and other key metabolic compounds. After quality control and missing data imputation, we performed univariable and multivariable analysis using normalized metabolites while adjusting for covariates, age, sex, socioeconomic status, and child's parish of birth. Our findings revealed unique metabolic patterns in children with ASD for four metabolites compared to TD controls. Notably, three metabolites were fatty acids, including myristoleic acid, eicosatetraenoic acid, and octadecenoic acid. The amino acid sarcosine exhibited a significant association with ASD. These findings highlight the role of metabolites in the etiology of ASD and suggest opportunities for the development of targeted interventions.

The effects of omega-3, DHA, EPA, Souvenaid® in Alzheimer's disease: A systematic review and meta-analysis.

Alzheimer's disease (AD) is the most common cause of dementia worldwide. Omega-3 fatty acids (n-3-PUFA) are essential to normal neural development and function. Souvenaid®, a medical supplement that contains n-3-PUFA's: eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA), has emerged as an alternative, slowing cognitive decline in AD patients. In this study, we investigated the effect of dietary supplementation with n-3-PUFA, EPA, DHA, and Souvenaid® in AD patients. This systematic review and meta-analysis aim to establish the relationship between n-3-PUFA, EPA, DHA, and Souvenaid® with cognitive effects, ventricular volume and adverse events in AD patients. A systematic search of randomized control trials (RCT), cohorts, and case-control studies was done in PubMed, Scopus, Web of Science, Cochrane, and Embase for AD adult patients with dietary supplementation with n-3-PUFA, EPA, DHA, or Souvenaid® between 2003 and 2024. We identified 14 studies with 2766 subjects aligned with our criteria. Most publications described positive cognitive outcomes from supplements (58%). The most common adverse events reported were gastrointestinal symptoms. CDR scale showed reduced progression of cognitive decline (SMD = -0.4127, 95% CI: [-0.5926; -0.2327]), without subgroup differences between different dietary supplement interventions. ADCS-ADL, MMSE, ADAS-cog, adverse events, and ventricular volume did not demonstrate significant differences. However, Souvenaid® showed a significant negative effect (SMD = -0.3593, 95% CI: -0.5834 to -0.1352) in ventricular volumes. The CDR scale showed reduced progression of cognitive decline among patients with n-3-PUFA supplemental interventions, with no differences between different n-3-PUFA supplements.

Analysis of the effect of early subcutaneous specific immunotherapy on the levels of dust mite allergen-specific antibodies and polyunsaturated fatty acid metabolism

Objective: To investigate the effects of subcutaneous immunotherapy (SCIT) on patients' immune markers and metabolic levels in the early stage of allergen treatment, and to gain insight into the role of SCIT in regulating immune responses and metabolic levels, so as to provide reference data for the further discovery of potential biomarkers. Methods: A longitudinal study was used to include 40 subjects who underwent SCIT with dust mite allergens in the Department of Pediatrics of the First Affiliated Hospital of Guangzhou Medical University between November 2017 and February 2022, including 20 subjects each of single mite subcutaneous immunotherapy (SM-SCIT) and double mite subcutaneous immunotherapy (DM-SCIT). In this study, levels of dust mite allergen-specific antibodies and polyunsaturated fatty acid metabolism were measured before and 12 months after treatment, while pulmonary function tests were performed. The therapeutic effects of the patients were followed up by visual analogue scale (VAS), asthma control test (ACT) and total medication scores (TMS). The results were statistically analyzed using t-test and Mann-Whitney U-test. Results: After 12 months of treatment with SCIT, both groups showed a significant decrease in total VAS score (SM-SCIT:Z=-2.298, P<0.05; DM-SCIT:Z=-3.411, P<0.001); total ACT score (SM-SCIT:Z=-2.054, P<0.05; DM-SCIT:Z=-2.014, P<0.05) and total medication scores (SM-SCIT:Z=-3.799, P<0.000 1; DM-SCIT:Z=-3.474, P<0.001) were significantly higher, in addition to significantly higher MMEF75/25 values in the DM-SCIT group (t=-2.253, P<0.05). There was no significant change in sIgE in the SM-SCIT group (P>0.05), and the sIgG4 levels of the Der p, Der f, p 1, p 2, f 2, and p 21 fractions were significantly elevated (Z=-2.651, -3.771, -2.949, -2.912, -2.725, -2.128, and -3.285, respectively, all P<0.05); The sIgE of Der p 2, f 2, p 7 and p 23 fractions(Z=-2.651, -3.771, -2.949, -2.912, -2.725, -2.128, -3.285, all P<0.05) and the sIgG4 levels of the Der p, Der f, p 1, p 2, f 1, f 2, p 10, p 21 and p 23 fractions (Z=-3.808, -3.845, -3.061, -2.688, -2.464, -3.211, -2.371, -2.091, -2.427, all P<0.05) of the DM-SCIT group were significantly elevated. Metabolomics analysis showed that arachidonic acid, docosahexaenoic acid, docosapentaenoic acid, eicosapentaenoic acid, 5, 9, 12-octadecatrienoic acid, 5(S)-hydroxylated eicosatetraenoic acid, and dihomo-gamma-linolenic acid were significantly elevated at the beginning of the treatment period after SM-SCIT treatment (Z of -2.191, -2.497, -1.988, -2.090, -2.19, -2.803, -2.073, all P<0.05); 5(S)-hydroxylated eicosatetraenoic acid showed elevated and alpha-linolenic acid, eicosadienoic acid, and eicosapentaenoic acid were significantly decreased in the DM-SCIT group after treatment (Z=-1.988, -2.090, -2.497, -1.988, respectively, all P<0.05). Correlation analysis showed that arachidonic acid was significantly negatively correlated with changes in dust mite-specific IgG4 (r=-0.499, P<0.05), and that alpha-linolenic acid, 5, 9, 12-octadecatrienoic acid, and eicosapentaenoic acid were positively correlated with the ΔsIgG4 of the dust mite der p 2 (r=0.451, 0.420, 0.474, respectively; all P<0.05). Conclusion: Significant changes in allergen-specific antibody levels and polyunsaturated fatty acid metabolism levels occur during SCIT, and the two may interact and influence each other.

Biochemical characterization of acyl-CoA:diacylglycerol acyltransferase2 from the diatom Phaeodactylum tricornutum and its potential effect on LC-PUFAs biosynthesis in planta

BackgroundEicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), belonging to ω-3 long-chain polyunsaturated fatty acids (ω3-LC-PUFAs), are essential components of human diet. They are mainly supplemented by marine fish consumption, although their native producers are oleaginous microalgae. Currently, increasing demand for fish oils is insufficient to meet the entire global needs, which puts pressure on searching for the alternative solutions. One possibility may be metabolic engineering of plants with an introduced enzymatic pathway producing ω3-LC-PUFAs.ResultIn this study we focused on the acyl-CoA:diacylglycerol acyltransferase2b (PtDGAT2b) from the diatom Phaeodactylum tricornutum, an enzyme responsible for triacylglycerol (TAG) biosynthesis via acyl-CoA-dependent pathway. Gene encoding PtDGAT2b, incorporated into TAG-deficient yeast strain H1246, was used to confirm its activity and conduct biochemical characterization. PtDGAT2b exhibited a broad acyl-CoA preference with both di-16:0-DAG and di-18:1-DAG, whereas di-18:1-DAG was favored. The highest preference for acyl donors was observed for 16:1-, 10:0- and 12:0-CoA. PtDGAT2b also very efficiently utilized CoA-conjugated ω-3 LC-PUFAs (stearidonic acid, eicosatetraenoic acid and EPA). Additionally, verification of the potential role of PtDGAT2b in planta, through its transient expression in tobacco leaves, indicated increased TAG production with its relative amount increasing to 8%. Its co-expression with the gene combinations aimed at EPA biosynthesis led to, beside elevated TAG accumulation, efficient accumulation of EPA which constituted even 25.1% of synthesized non-native fatty acids (9.2% of all fatty acids in TAG pool).ConclusionsThis set of experiments provides a comprehensive biochemical characterization of DGAT enzyme from marine microalgae. Additionally, this study elucidates that PtDGAT2b can be used successfully in metabolic engineering of plants designed to obtain a boosted TAG level, enriched not only in ω-3 LC-PUFAs but also in medium-chain and ω-7 fatty acids.

Sustainable fish oil extraction from catfish visceral biomass: A comparative study between high-shear homogenization and high-frequency ultrasound on wet rendering process

Traditional wet rendering leads to the degradation of polyunsaturated fatty acids in fish oil. Therefore, we combined this method with high-shear homogenization and high-frequency ultrasound to extract oil from Clarias magur visceral biomass. This way, we aimed to achieve higher oil yield, shorter extraction times, and a better preservation of polyunsaturated fatty acids. High-shear homogenization and high-frequency ultrasound increased the oil yields by 9.17 and 10.55%, respectively, compared to traditional wet rendering. The oil quality was also improved, with lower acid and peroxide values. Scanning electron microscopy confirmed enhanced cell disruption for increasing the oil extraction efficiency. Fourier transfer infrared spectroscopy also proved the efficacy of homogenization and ultrasound pretreatment in enhancing the extraction of polyunsaturated fatty acids from C. magur visceral biomass. Their content showed a significant variation among different extraction methods. Specifically, the high-frequency ultrasound method resulted in a notable 15.1% increase, while the high-shear homogenization method demonstrated a significant 13.3% increase, compared to the wet rendering method (control). The oil extracted by the high-frequency ultrasound method demonstrated a 7.5% increase in eicosatetraenoic acid and a 11.7% increase in docosahexaenoic acid, as compared to the oil obtained from the control method. High-shear homogenization and high-frequency ultrasound shortened the extraction time and reduced the temperature requirements for oil extraction from wet biomass. These techniques have potential for efficient fish oil extraction, valuable in the healthcare and food industries.

Differential Remodeling of the Oxylipin Pool After FLASH Versus Conventional Dose-Rate Irradiation In Vitro and In Vivo

The products of lipid peroxidation have been implicated in human diseases and aging. This prompted us to investigate the response to conventional (CONV) versus FLASH irradiation of oxylipins, a family of bioactive lipid metabolites derived from omega-3 or omega-6 polyunsaturated fatty acids through oxygen-dependent non-enzymatic as well as dioxygenase-mediated free radical reactions. Ultrahigh performance liquid chromatography coupled to tandem mass spectrometry was used to quantify the expression of 37 oxylipins derived from eicosatetraenoic, eicosapentaenoic and docosahexaenoic acid in mouse lung and in normal or cancer cells exposed to either radiation modality under precise monitoring of the temperature and oxygenation. Among the 37 isomers assayed, 14-16 were present in high enough amount to enable quantitative analysis. The endpoints were the expression of oxylipins as a function of the dose of radiation, normoxia versus hypoxia, temperature and post-irradiation time. In normal, normoxic cells at 37°C radiation elicited destruction and neosynthesis of oxylipins acting antagonistically on a background subject to rapid remodeling by oxygenases. Neosynthesis was observed in the CONV mode only, in such a way that the level of oxylipins at 5 minutes after FLASH irradiation was 20-50% lower than in non-irradiated and CONV-irradiated cells. Hypoxia mitigated the differential CONV versus FLASH response in some oxylipins. These patterns were not reproduced in tumor cells. Depression of specific oxylipins following FLASH irradiation was observed in mouse lung at 5 min following irradiation, with near complete recovery in 24 hours and further remodeling at one week and two months post-irradiation. Down-regulation of oxylipins was a hallmark of FLASH irradiation specific of normal cells. Temperature effects suggest that this process occurs via diffusion-controlled, bimolecular recombination of a primary radical species upstream from peroxyl radical formation and evoke a major role of the membrane composition and fluidity in response to the FLASH modality.

Oil from Mullet Roe Byproducts: Effect of Oil Extraction Method on Human Erythrocytes and Platelets.

Background: The valorization of byproducts to obtain high nutritional value foods is of utmost importance for our planet where the population is booming. Among these products are oils rich in ω-3 fatty acids produced from fishery byproducts. Recently, mullet roe oil from roe byproducts was produced that was rich in the ω-3 fatty acids eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA). Oils are customarily characterized for their composition and degree of oxidation but little is known of their biological effects, especially the effect of the extraction method. Methods: The purpose of this study was to evaluate the effects of freshly extracted mullet roe oil from mullet roe byproducts and the effect of the extraction method on human red blood cells (hRBCs) and platelets. To this end, the hemocompatibility (cytotoxicity), oxidative effects, and erythrocyte membrane changes were examined after 1 and 24 h of incubation. Antiplatelet effects were also assessed in vitro. Results: The expeller press oil extraction method and alcalase-assisted extraction produced the most biocompatible oils, as shown by hemocompatibility measurements and the absence of erythrocyte membrane alterations. Solvent extracts and protease-assisted extraction oils resulted in the rupture of red blood cells at different examined dilutions, creating hemolysis. Conclusions: It seems that the proper functioning of oil-erythrocyte interactions cannot be explained solely by ROS. Further investigations combining chemical analysis with oil-cell interactions could be used as an input to design high nutritional value oils using green extraction technologies. All samples exhibited promising antiplatelet and antiblood clotting effects in vitro.

Association between dietary omega-3 intake and coronary heart disease among American adults: The NHANES, 1999-2018.

Omega-3 has been extensively studied for its cardiovascular disease (CVD) benefits. However, the results of this evidence are inconsistent. Therefore, in this study, dietary omega-3 intake was investigated further in relation to coronary heart disease (CHD) risk among U.S. adults. We used data from the National Health and Nutrition Examination Survey (NHANES) database for people ages 20 years and older between 1999 and 2018 to conduct a cross-sectional survey. The Medical Condition Questionnaire (MCQ) was used to determine CHD status. We measured dietary omega-3 intake using two 24-hour dietary recall interviews. Multivariate logistic regression and subgroup analysis were used to explore the correlation between dietary omega-3 intake and CHD. The dose-response relationship between the two was analyzed with a restricted cubic spline (RCS). 31,184 study subjects were included, of whom 1,604 (5.14%) were patients with CHD. By quintile (Q) of dietary omega-3 intake, after adjusting for all confounding factors, compared with Q1, when total dietary omega-3, alpha-linolenic acid (ALA), docosapentaenoic acid (DPA), eicosatetraenoic acid (ETA), eicosapentaenoic acid (EPA), and docosahexenoic acid (DHA) intake reached Q5, the odds ratio (95% confidence interval, CI) of CHD were 0.76 (0.60, 0.96), 0.73 (0.57, 0.94), 0.70 (0.54, 0.92), 0.66 (0.50, 0.85), 0.84 (0.69, 1.02), and 0.83 (0.64, 1.07), respectively, while EPA and DHA were not significantly associated with the disease (Trend p > 0.05). Intake of omega-3 and CHD were linearly related (P for nonlinear = 0.603). No significant interactions were found within subgroups except for the age group (P for interaction = 0.001). Sensitivity analysis and multivariate logistic regression results are generally in agreement. Total dietary omega-3, ALA, DPA, and ETA intake were negatively associated with CHD risk. In contrast, EPA and DHA had no significant correlation with CHD.

Effect of Primary Versus Revisional One Anastomosis Gastric Bypass (OAGB) on Fatty Acid Profile

IntroductionOne anastomosis gastric bypass (OAGB) is one option of a revisional procedure for failed sleeve gastrectomy. Moreover, it can be used as a primary bariatric procedure, and is an effective surgery resulting in significant weight loss and the resolution or improvement of obesity-associated medical problems, accompanied by low perioperative complications. However, as with any therapy, OAGB has its limitations, including micronutrient deficiency or malnutrition. In our study, we compared the fatty acid (FA) profile in serum of patients after both primary OAGB (pOAGB) and revisional OAGB (rOAGB) to identify potential postsurgical FA alterations.MethodsThis is a retrospective study on patients with obesity who underwent OAGB procedures (pOAGB n=68; rOAGB n=17), conducted from 2016 to 2018. In blood, we analyzed a series of biochemical parameters, and in the serum, the FA profile was determined using gas chromatography-mass spectrometry.ResultsThe percentage of excess BMI loss (% EBMIL) after pOAGB was 73.5 ± 2.47% in comparison to 45.9 ± 4.15% in the rOAGB group (p<0.001). In contrast to the lack of effect of rOAGB on most polyunsaturated FAs, in the pOAGB group, there was a decrease in eicosapentaenoic acid, and eicosatetraenoic and docosahexaenoic acid levels (p<0.001). We also found a decrease in very long-chain FAs (VLCFAs) and an increase in branched-chain FAs (BCFAs) after both types of OAGB procedure.ConclusionsBoth OAGB procedures improved the profile of most FAs, leading to a decrease in VLCFAs, which are considered harmful, and an improvement in BCFAs, which are considered to be beneficial. There is a need to further investigate the possibility of n-3 polyunsaturated FA supplementation after pOAGB, due to the large decrease in these FAs after pOAGB.Graphical

Genetic Polymorphisms in the Ferrireductase STEAP3 Regulate a Ferroptosis-like Process of Lipid Peroxidation-Induced Hemolysis in Murine and Human Red Blood Cells

Red blood cell (RBC) storage in the blood bank induces a series of biochemical and morphological alterations, collectively denoted as the storage lesion(s). Membrane damage by lipid peroxidation is a hallmark of the storage lesion, a process thought to be triggered by oxidant stress. To identify the genetics underlying this phenomenon, we leveraged a novel murine system, the Jackson lab Diversity Outbred (JDO) mouse colony, which was obtained by extensively cross-breeding 8 founder mouse strains with extreme genetically heterogeneity ( Figure 1.A). A total of 350 fresh and stored (up to 7 days) murine RBC samples were tested by mass spectrometry-based metabolomics and lipidomics. At the end of storage, post-transfusion recovery (PTR), which measures intra- and extravascular hemolysis and is a gold standard for determining RBC storage quality, was determined by quantifying the percentage of stored RBCs that were still circulating 24h after their transfusion into Ubi-GFP+ recipient mice ( Figure 1.A). Genome wide-association studies identified a strong association between PTR and a polymorphic region on chromosome 1 ( Figure 1.A), which encodes STEAP3, a ferrireductase. This region was associated with altered metabolism of stored RBCs ( Figure 1.A), especially an elevation of lipid peroxidation products (hive plot in Figure 1.A). Mechanistically, these data support a role for STEAP3 in promoting Fenton and Haber-Weiss chemistry in iron-loaded RBCs. Specifically, ferrous iron participates in this chemistry, becoming oxidized to its ferric state with concomitant generation of hydroxyl or hydroperoxyl radicals; these in turn attack fatty acids (preferentially, poly- and highly-unsaturated fatty acids, such as octadecadienoic and eicosatetraenoic acid), thereby promoting lipid peroxidation (to hydroxyoctadecadienoic (HODE) and hydroxyeicosatetraenoic (HETE) acids, respectively). By reducing Fe 3+ to Fe 2+, STEAP3 can shift the balance of this reaction by increasing the availability of the reactant, thereby favoring the generation of product radicals; this process is analogous to ferroptosis, as described in other biological systems. To extend the relevance of these findings to humans, we performed metabolomics on end-of-storage (i.e., Day 42) packed RBCs from 13,091 human donors in the Recipient Epidemiology and Donor Evaluation Study (REDS RBC Omics; Figure 1.B), enrolled in four blood centers across the United States. We stratified donors based on oxylipin levels (e.g., acids - HETEs - Figure 1.B) and common STEAP3 polymorphisms (e.g., a representative non-synonymous coding single nucleotide polymorphism (SNP), rs17013371, was observed with ~10% prevalence in these donors), along with 37 other common SNPs observed in this study ( Figure 1.B). When correlating metabolic and hematological parameters to common STEAP3 non-synonymous coding SNPs, we found strong associations of such polymorphisms with RBC susceptibility to hemolysis (either osmotic or oxidative), lipid peroxidation, RBC numbers, and hemoglobin levels ( Figure 1.B). These associations held true for a subset of the original donors with extreme hemolytic propensity (n=643) who donated a second RBC unit that was again stored for 42 (i.e., the “recalled donor population”). In the initial (n=13,091) and recalled donor (n=643) populations, lipid peroxidation products, HETEs, and HODEs ranked as the top predictors of hemolysis and vesiculation. In summary, we identified a role for the STEAP3 ferrireductase in contributing to a ferroptosis-like phenotype of lipid peroxidation that is associated with increased susceptibility to hemolysis in vitro and in vivo in murine and human RBCs following storage under blood bank conditions. Figure 1 - A. Jackson Lab diversity outbred (JDO) mice were bred from 8 founder mouse strains with extreme genetic heterogeneity. A total of 350 fresh and stored murine red blood cells (RBCs) were tested for metabolomics, lipidomics, and post-transfusion recovery (PTR). A polymorphic region on chromosome 1, coding for the ferrireductase STEAP3 was associated with heterogeneous PTR and elevation in lipid peroxidation products. B. Metabolomics analyses of 13,091 donors from the REDS RBC Omics identified an association between the end of storage levels of oxylipins and common polymorphisms for STEAP3, both linked to an increased RBC susceptibility to hemolysis (either osmotic or oxidative.

Apelin receptor inhibition in ischemia-reperfused mouse hearts protected by endogenous n-3 polyunsaturated fatty acids.

Background: While the protective effects of n-3 polyunsaturated fatty acids (PUFAs) on cardiac ischemia-reperfusion (IR) injury have been previously reported, limited data are available regarding how these fatty acids affect membrane receptors and their downstream signaling following IR injury. We aimed to identify potential receptors activated by n-3 PUFAs in IR hearts to understand the regulatory mechanisms of these receptors. Methods: We used fat-1 mice, which naturally have elevated levels of n-3 PUFAs, and C57BL/6J mice as a control group to create a myocardial IR injury model through Langendorff perfusion. We assessed the impact of endogenous n-3 PUFAs on left ventricular function, myocardial infarct size, myocardial apoptosis, and ATP production. RNA sequencing (RNA-seq) and bioinformatics analysis were conducted to identify molecular targets affected by n-3 PUFAs. Based on these analyses we then treated IR hearts of WT and fat-1 mice with an antagonist (ML221) or an agonist (apelin-13) for the predicted receptor to assess cardiac contractile function and intracellular signaling pathways. An in vitro hypoxia-reoxygenation (HR) model was also used to confirm the effects of n-3 PUFAs on the examined intracellular signaling pathways. Results: Endogenous n-3 PUFAs protected cardiac structure and function in post-IR hearts, and modulated phosphorylation patterns in the PI3K-AKT-mTOR signaling pathways. RNA-seq analysis revealed that n-3 PUFAs affected multiple biological processes as well as levels of the apelin receptor (APLNR). Consistent with a role for the PLNNR, ML221 synchronized the activation of the PI3K-AKT-mTOR signaling axis, suppressed the expression of PKCδ and phosphorylated p38α, upregulated PKCε expression, upregulated or restored the phosphorylation of myofilaments, and prevented myocardial injury and contractile dysfunction in WT IR hearts. By contrast, apelin-13 disrupted the PI3K-AKT-mTOR signaling axis in post-IR fat-1 hearts. The phosphorylation signaling targeted by APLNR inhibition in post-IR fat-1 hearts was also observed after treating HR cells with eicosatetraenoic acid (EPA). Conclusion: Endogenous n-3 PUFAs protect against post-IR injury and preserve cardiac contractile function possibly through APLNR inhibition. This inhibition synchronizes the PI3K-AKT-mTOR axis, suppresses detrimental phosphorylation signaling, and restores or increases myofilament phosphorylation in post-IR hearts. The beneficial effects observed in fat-1 transgenic mouse hearts can be attributed, at least in part, to elevated EPA levels. This study is the first to demonstrate that n-3 PUFAs protect hearts against IR injury through APLNR inhibition.

Abnormalities of serum lipid metabolism in patients with acute paraquat poisoning caused by ferroptosis

As the mechanism of paraquat (PQ) poisoning is still not fully elucidated, and no specific treatment has been developed in medical practice, the management of PQ poisoning continues to present a medical challenge. In this study, the objective was to investigate the early metabolic changes in serum metabolism and identify the key metabolic pathways involved in patients with PQ poisoning. Quantitative analysis was conducted to determine the relevant metabolites. Additionally, experiments were carried out in both plasma and cell to elucidate the mechanisms underlying metabolic disorder and cell death in PQ poisoning. The study found that polyunsaturated fatty acids (PUFAs) and their metabolites, such as arachidonic acid (AA) and hydroxy eicosatetraenoic acids (HETEs), were significantly increased by non-enzymatic oxidative reaction. Reactive oxygen species (ROS) production increased rapidly at 2 h after PQ poisoning, followed by an increase in PUFAs at 12 h, and intracellular glutathione, cysteine (Cys), and Fe2+ at 24 h. However, at 36 h later, intracellular glutathione and Cys decreased, HETEs increased, and the expression of SLC7A11 and glutathione peroxidase 4 (GPX4) decreased. Ultrastructural examination revealed the absence of mitochondrial cristae. Deferoxamine was found to alleviate lipid oxidation, and increase the viability of PQ toxic cells in the low dose. In conclusion, unsaturated fatty acids metabolism was the key metabolic pathways in PQ poisoning. PQ caused cell death through the induction of ferroptosis. Inhibition of ferroptosis could be a novel strategy for the treatment of PQ poisoning.

Associations of polyunsaturated fatty acids with cardiovascular disease and mortality: a study of NHANES database in 2003–2018

BackgroundThis study was to explore the association between dietary polyunsaturated fatty acids (PUFAs) consumption and cardiovascular diseases (CVDs), all-cause mortality, and CVD-specific mortality.MethodsThis retrospective cohort study extracted demographic and clinical data of 38,838 adult participants from the National Health and Nutrition Examination Survey (NHANES) database in 2003–2018. We explored the association between octadecadienoic acid (ODA), octadecatrienoic acid (ALA), octadecatetraenoic acid (ODTA), eicosatetraenoic acid (AA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) and different CVDs using weighted univariate and multivariate logistic regression analyses with odds ratio (OR) and 95% confidence interval (CI). The PUFAs were divided into four levels according to the quartiles (≤ Q1, Q1 to Q2, Q1 to Q2, > Q3). Weighted univariate and multivariate COX regression analyses with hazard ratio (HR) and 95% CI were used for exploring the association between PUFAs and all-cause mortality, CVD-specific mortality and other cause-specific mortality.ResultsDuring the follow-up, a total of 4,908 (9.12%) eligible participants died. The results showed that after adjusting for covariates, ODTA intake was related to low odds of coronary heart disease (CHD) [OR = 0.75, 95%CI: (0.64–0.88)]. Q1-Q2 quartile of ALA [OR = 0.81, 95%CI: (0.66–0.99)] and Q2-Q3 quartile of DPA [OR = 0.78, 95%CI: (0.62–0.99)] intakes were linked to low odds of heart attack, and > Q3 quartile of ODA intake was associated with low odds of congestive heart failure (CHF) [OR = 0.66, 95%CI: (0.49–0.90)] and stroke [OR = 0.65, 95%CI: (0.47–0.90)]. Q2-Q3 quartile of DPA intake was linked to low odds of angina [OR = 0.76, 95%CI: (0.58–0.99)]. Higher ALA intake was associated with a lower risk of all-cause mortality [Q2-Q3: HR = 0.86, 95%CI: (0.74–0.99); > Q3: HR = 0.76, 95%CI: (0.63–0.91)]. Additionally, Q2-Q3 quartile of ALA, Q1-Q2 quartile of AA and DPA intakes were respectively related to a low risk of CVD-specific mortality, while that > Q3 quartile of ALA related to that of mortality by other causes.ConclusionOur study found that PUFAs were associated with different CVDs, and higher ALA intake was related to lower risk of all-cause mortality. Ensuring adequate intake of PUFAs was beneficial to the health and may decrease the risk of mortality.

Recombinant Soybean Lipoxygenase 2 (GmLOX2) Acts Primarily as a ω6(S)-Lipoxygenase.

The lipoxygenase (LOX) cascade is a source of bioactive oxylipins that play a regulatory role in plants, animals, and fungi. Soybean (Glycine max (L.) Merr.) LOXs are the classical models for LOX research. Progress in genomics has uncovered a large diversity of GmLOX isoenzymes. Most of them await biochemical investigations. The catalytic properties of recombinant soybean LOX2 (GmLOX2) are described in the present work. The GmLOX2 gene has been cloned before, but only for nucleotide sequencing, while the recombinant protein was not prepared and studied. In the present work, the recombinant GmLOX2 behavior towards linoleic, α-linolenic, eicosatetraenoic (20:4), eicosapentaenoic (20:5), and hexadecatrienoic (16:3) acids was examined. Linoleic acid was a preferred substrate. Oxidation of linoleic acid afforded 94% optically pure (13S)-hydroperoxide and 6% racemic 9-hydroperoxide. GmLOX2 was less active on other substrates but possessed an even higher degree of regio- and stereospecificity. For example, it converted α-linolenic acid into (13S)-hydroperoxide at about 98% yield. GmLOX2 showed similar specificity towards other substrates, producing (15S)-hydroperoxides (with 20:4 and 20:5) or (11S)-hydroperoxide (with 16:3). Thus, the obtained data demonstrate that soybean GmLOX2 is a specific (13S)-LOX. Overall, the catalytic properties of GmLOX2 are quite similar to those of GmLOX1, but pH is optimum.

Construction of Eicosatetraenoic Acid Producing Cell Factory by Genetic Engineering of Mucor circinelloides

Eicosatetraenoic acid (ETA, 20:4, ω-3) is the desaturation product of dihomo-gamma linolenic acid (DGLA, 20:3, ω-6) catalyzed by delta-17 desaturase, which is considered as a healthy product that helps to lower risk of heart diseases. The oleaginous filamentous fungus, Mucor circinelloides, has been used for a long time as a model micro-organism for GLA production at industrial scales. However, M. circinelloides lacks the key enzymes to synthesize C20 polyunsaturated fatty acids (PUFAs). M. circinelloides could produce DGLA by overexpressing the D6E(GLELO) gene, which could be a useful tool to produce ETA due to the availability of established genetic manipulation tools. Therefore, in this study, delta-17 desaturase (PpD17 and PaD17) genes from Phytophthora parasitica and Pythium aphanidermatum, respectively, were introduced into M. circinelloides to construct an ETA-producing cell factory. Our results showed that the PaD17 and PpD17 overexpression strains’ biomass increased by 25.98 and 23.34 g/L (39.98 and 25.75%), respectively, compared with the control strain. Meanwhile, the lipid contents of the recombinant strains also increased and reached up to 28.88% in Mc-PaD17 and 30.95% in Mc-PpD17, respectively, compared with the control strain (23.38% in Mc-2076). The RT-qPCR results showed that overexpression of delta-17 desaturase genes promoted the expression of cme2, fas2, and D6E, thereby contributing to lipid biosynthesis in M. circinelloides. Meanwhile, the content of ETA reached up to 1.95%, and the yield of ETA was up to 114.69 mg/L in PpD17 overexpression mutants at 96 h. This study provided the first report on the construction of an ETA-producing cell factory by heterologous overexpression of the PpD17 gene in M. circinelloides, which established a new scope for further research in the production of ETA in oleaginous fungi.