E-series resolvin metabolome, biosynthesis and critical role of stereochemistry of specialized pro-resolving mediators (SPMs) in inflammation-resolution: Preparing SPMs for long COVID-19, human clinical trials, and targeted precision nutrition.

The COVID-19 pandemic has raised international awareness of the importance of rigorous scientific evidence and the havoc caused by uncontrolled excessive inflammation. Here we consider the evidence on whether the specialized pro-resolving mediators (SPMs) are ready to meet this challenge as well as targeted metabololipidomics of the resolution-inflammation metabolomes. Specific stereochemical mechanisms in the biosynthesis of SPMs from omega-3 essential fatty acids give rise to unique local-acting lipid mediators. SPMs possess stereochemically defined potent bioactive structures that are high-affinity ligands for cognate G protein-coupled surface receptors that evoke the cellular responses required for efficient resolution of acute inflammation. The SPMs biosynthesized from the major omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are coined Resolvins (resolution phase interaction products; E series and D-series), Protectins and Maresins (macrophage mediators in resolving inflammation). Their biosynthesis and stereochemical assignments are established and confirmed (>1,441 resolvin publications in PubMed.gov) as well as their functional roles on innate immune cells and adaptive immune cells (both lymphocyte T-cell subsets and B-cells). The resolution of a protective acute inflammatory response is governed mainly by phagocytes that actively clear apoptotic cells, debris, blood clots and pathogens. These resolution phase functions of the acute inflammatory response are enhanced by SPMs, which together prepare the inflammatory loci for homeostasis and stimulate tissue regeneration via activating stem cells and the biosynthesis of novel cys-SPMs (e.g. MCTRs, PCTRs and RCTRs). These cys-SPMs also activate regeneration, are organ protective and stimulate resolution of local inflammation. Herein, we review the biosynthesis and functions of the E-series resolvins, namely resolvin E1 (the first n-3 resolvin identified), resolvin E2, resolvin E3 and resolvin E4 biosynthesized from their precursor eicosapentaenoic acid (EPA), and the critical role of total organic synthesis in confirming SPM complete stereochemistry, establishing their potent functions in resolution of inflammation, and novel structures. The physical properties of each biologically derived SPM, i.e., ultra-violet (UV) absorbance, chromatographic behavior, and tandem mass spectrometry (MS2) fragmentation, were matched to SPMs biosynthesized and prepared by stereospecific total organic synthesis. We briefly review this approach, also used with the endogenous D-series resolvins, protectins and maresins confirming their potent functions in resolution of inflammation, that paves the way for their rigorous evaluation in human tissues and clinical trials. The assignment of complete stereochemistry for each of the E and D series Resolvins, Protectins and Maresins was a critical and required step that enabled human clinical studies as in SPM profiling in COVID-19 infections and experimental animal disease models that also opened the promise of resolution physiology, resolution pharmacology and targeted precision nutrition as new areas for monitoring health and disease mechanisms.

Exploring the role of E. faecalis enterococcal polysaccharide antigen (EPA) and lipoproteins in evasion of phagocytosis.

Enterococcus faecalis is an opportunistic pathogen frequently causing nosocomial infections. The virulence of this organism is underpinned by its capacity to evade phagocytosis, allowing dissemination in the host. Immune evasion requires a surface polysaccharide produced by all enterococci, known as the enterococcal polysaccharide antigen (EPA). EPA consists of a cell wall-anchored rhamnose backbone substituted by strain-specific polysaccharides called 'decorations', essential for the biological activity of this polymer. However, the structural determinants required for innate immune evasion remain unknown, partly due to a lack of suitable validated assays. Here, we describe a quantitative, in vitro assay to investigate how EPA decorations alter phagocytosis. Using the E. faecalis model strain OG1RF, we demonstrate that a mutant with a deletion of the locus encoding EPA decorations can be used as a platform strain to express heterologous decorations, thereby providing an experimental system to investigate the inhibition of phagocytosis by strain-specific decorations. We show that the aggregation of cells lacking decorations is increasing phagocytosis and that this process does not involve the recognition of lipoproteins by macrophages. Collectively, our work provides novel insights into innate immune evasion by enterococci and paves the way for further studies to explore the structure/function relationship of EPA decorations.

Omega-3 polyunsaturated fatty acids and Parkinson's disease: A systematic review of animal studies.

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The primary pathological features of PD include the presence of α-synuclein aggregates and Lewy bodies, mitochondrial dysfunction, oxidative stress, and neuroinflammation. Recently, omega-3 fatty acids (ω-3 PUFAs) have been under investigation as a preventive and/or therapeutic strategy for PD, primarily owing to their antioxidant and anti-inflammatory properties. Therefore, the objective of this study was to conduct a systematic review of the literature, focusing on studies that assessed the effects of ω-3 PUFAs in rodent models mimicking human PD. The search was performed using the terms "Parkinson's disease," "fish oil," "omega 3," "docosahexaenoic acid," and "eicosapentaenoic acid" across databases PUBMED, Web of Science, Science Direct, Scielo, and Google Scholar. Following analysis based on predefined inclusion and exclusion criteria, 39 studies were included. Considering behavioral parameters, pathological markers of the disease, quantification of ω-3 PUFAs in the brain, as well as anti-inflammatory, antioxidant, and anti-apoptotic effects, it can be observed that ω-3 PUFAs exhibit a potential neuroprotective effect in PD. In summary, this systematic review presents significant scientific evidence regarding the effects and mechanisms underlying the neuroprotective properties of ω-3 PUFAs, offering valuable insights for the development of future clinical investigations.

Essential omega-3 fatty acids are depleted in sea ice and pelagic algae of the Central Arctic Ocean.

Microalgae are the main source of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), essential for the healthy development of most marine and terrestrial fauna including humans. Inverse correlations of algal EPA and DHA proportions (% of total fatty acids) with temperature have led to suggestions of a warming-induced decline in the global production of these biomolecules and an enhanced importance of high latitude organisms for their provision. The cold Arctic Ocean is a potential hotspot of EPA and DHA production, but consequences of global warming are unknown. Here, we combine a full-seasonal EPA and DHA dataset from the Central Arctic Ocean (CAO), with results from 13 previous field studies and 32 cultured algal strains to examine five potential climate change effects; ice algae loss, community shifts, increase in light, nutrients, and temperature. The algal EPA and DHA proportions were lower in the ice-covered CAO than in warmer peripheral shelf seas, which indicates that the paradigm of an inverse correlation of EPA and DHA proportions with temperature may not hold in the Arctic. We found no systematic differences in the summed EPA and DHA proportions of sea ice versus pelagic algae, and in diatoms versus non-diatoms. Overall, the algal EPA and DHA proportions varied up to four-fold seasonally and 10-fold regionally, pointing to strong light and nutrient limitations in the CAO. Where these limitations ease in a warming Arctic, EPA and DHA proportions are likely to increase alongside increasing primary production, with nutritional benefits for a non-ice-associated food web.

Omega-3 Polyunsaturated Fatty Acids are not associated with Peripheral Artery Disease in a Meta-Analysis from the Multi-Ethnic Study of Atherosclerosis and Atherosclerosis Risk in Communities Study Cohorts.

BACKGROUND: Research suggests omega-3 polyunsaturated fatty acids (PUFAs) exert favorable effects on several biological processes involved in the development and progression of atherosclerotic cardiovascular disease (ASCVD). However, studies examining the relationship between omega-3 PUFAs and peripheral artery disease (PAD) are scarce. OBJECTIVES: We evaluated the associations between omega-3 PUFAs and incident PAD in a meta-analysis of the Multi-Ethnic Study of Atherosclerosis (MESA) and Atherosclerosis Risk in Communities (ARIC) study cohorts. METHODS: Omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were measured at baseline for all MESA (n = 6495) and Minnesota ARIC participants (n = 3612). Incident clinical PAD events (MESA n = 106; ARIC n = 149) identified primarily through ICD discharge codes were assessed through follow-up of each cohort. Associations between omega-3 PUFAs (EPA, DHA, and EPA+DHA) and incident PAD were modeled in MESA and ARIC as quartiles and continuously using Cox proportional hazards regression, respectively. A fixed-effects meta-analysis was conducted to evaluate associations in the 2 cohorts combined. RESULTS: In the fully adjusted model, in 10,107 participants, no significant associations were observed between EPA, DHA, or EPA+DHA, and incident PAD modeled as quartiles or continuously for either MESA or ARIC cohorts separately or in the meta-analysis after a follow-up of approximately 15 y. CONCLUSION: This study is consistent with previous literature indicating that the beneficial effects of omega-3 PUFAs on the markers of ASCVD may not translate to a clinically meaningful decrease in PAD risk.

Docosahexaenoic and Eicosapentaenoic Acids Promote the Accumulation of Browning-Related Myokines via Calcium Signaling in Insulin-Resistant Mice.

BACKGROUND: Myokines have a prominent effect on improving insulin resistance (IR) by inducing browning of white adipose tissue (WAT). Although docosahexaenoic acids (DHA) and eicosapentaenoic acids (EPA) play roles in improving IR and stimulating browning, whether they mediate myokines directly remains unknown. OBJECTIVE: This study aims to investigate the effects of DHA and EPA on browning-related myokines under IR and clarify the mechanism via Ca2+ signaling. METHODS: The expression and secretion levels of myokines in IR mice and IR myotubes were detected after DHA/EPA treatment. The crosstalk between myotubes and adipocytes was evaluated through a method in which IR adipocytes were treated with the culture medium supernatant of myotubes treated with DHA/EPA. The expression of browning markers in the WAT of IR mice and adipocytes was determined. A calcium chelator was used to determine whether DHA and EPA regulate myokine production through a calcium ion-dependent pathway. RESULTS: In vivo experiments: 3:1 and 1:3 DHA/EPA promoted the mRNA levels of Irisin, IL-6, IL-15, and FGF21 in skeletal muscle, stimulated WAT browning, reduced lipid accumulation; 3:1 DHA/EPA upregulated the serum concentration of Irisin; 1:3 DHA/EPA upregulated the serum concentrations of Irisin, IL-6, and FGF21. In vitro experiments: the levels of Irisin and IL-6 in C2C12 myotubes and their medium supernatant were significantly elevated in the 3:1 and 1:3 groups and the upregulation of browning markers and reduction in fat accumulation were observed in adipocytes treated with the medium supernatant of C2C12 myotubes in the 3:1 and 1:3 groups. However, the above phenomena disappeared when Ca2+ signaling was inhibited. CONCLUSIONS: Treatment with DHA and EPA at composition ratios of 3:1 and 1:3 induces browning of WAT in IR mice, which is likely related to the promotion of the accumulation of myokines, especially Irisin and IL-6, via Ca2+ signaling.

Sex, Body Mass Index, and APOE4 Increase Plasma Phospholipid-Eicosapentaenoic Acid Response During an ω-3 Fatty Acid Supplementation: A Secondary Analysis.

BACKGROUND: The brain is concentrated with omega (ω)-3 (n-3) fatty acids (FAs), and these FAs must come from the plasma pool. The 2 main ω-3 FAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), must be in the form of nonesterified fatty acid (NEFA) or esterified within phospholipids (PLs) to reach the brain. We hypothesized that the plasma concentrations of these ω-3 FAs can be modulated by sex, body mass index (BMI, kg/m2), age, and the presence of the apolipoprotein (APO) E-ε4 allele in response to the supplementation. OBJECTIVES: This secondary analysis aimed to determine the concentration of EPA and DHA within plasma PL and in the NEFA form after an ω-3 FA or a placebo supplementation and to investigate whether the factors change the response to the supplement. METHODS: A randomized, double-blind, placebo-controlled trial was conducted. Participants were randomly assigned to either an ω-3 FA supplement (DHA 0.8 g and EPA 1.7 g daily) or to a placebo for 6 mo. FAs from fasting plasma samples were extracted and subsequently separated into PLs with esterified FAs and NEFAs using solid-phase extraction. DHA and EPA concentrations in plasma PLs and as NEFAs were quantified using gas chromatography. RESULTS: EPA and DHA concentrations in the NEFA pool significantly increased by 31%-71% and 42%-82%, respectively, after 1 and 6 mo of ω-3 FA supplementation. No factors influenced plasma DHA and EPA responses in the NEFA pool. In the plasma PL pool, DHA increased by 83%-109% and EPA by 387%-463% after 1 and 6 mo of ω-3 FA supplementation. APOE4 carriers, females, and individuals with a BMI of ≤25 had higher EPA concentrations than noncarriers, males, and those with a BMI of >25, respectively. CONCLUSIONS: The concentration of EPA in plasma PLs are modulated by APOE4, sex, and BMI. These factors should be considered when designing clinical trials involving ω-3 FA supplementation. This trial was registered at clinicaltrials.gov as NCT01625195.

A 12-week randomized double-blind clinical trial of eicosapentaenoic acid intervention in episodic migraine.

Omega-3 polyunsaturated fatty acids (PUFAs) may benefit migraine improvement, though prior studies are inconclusive. This study evaluated the effect of eicosapentaenoic acid (EPA) on episodic migraine (EM) prevention. Seventy individuals with EM participated in a 12-week randomized, double-blind, placebo-controlled trial from March 2020 and May 2022. They were randomly assigned to either the EPA (N = 35, 2 g fish oil with 1.8 g of EPA as a stand-alone treatment daily), or the placebo group (N = 35, 2 g soybean oil daily). Migraine frequency and headache severity were assessed using the monthly migraine days, visual analog scale (VAS), Migraine Disability Assessment (MIDAS), Hospital Anxiety and Depression Scale (HADS), Migraine-Specific Quality-of-Life Questionnaire (MSQ), and Pittsburgh Sleep Quality Index (PSQI) in comparison to baseline measurements. The EPA group significantly outperformed the placebo in reducing monthly migraine days (-4.4 ± 5.1 days vs. - 0.6 ± 3.5 days, p = 0.001), days using acute headache medication (-1.3 ± 3.0 days vs. 0.1 ± 2.3 days, p = 0.035), improving scores for headache severity (ΔVAS score: -1.3 ± 2.4 vs. 0.0 ± 2.2, p = 0.030), disability (ΔMIDAS score: -13.1 ± 16.2 vs. 2.6 ± 20.2, p = 0.001), anxiety and depression (ΔHADS score: -3.9 ± 9.4 vs. 1.1 ± 9.1, p = 0.025), and quality of life (ΔMSQ score: -11.4 ± 19.0 vs. 3.1 ± 24.6, p = 0.007). Notably, female particularly benefited from EPA, underscoring its potential in migraine management. In conclusion, high-dose EPA has significantly reduced migraine frequency and severity, improved psychological symptoms and quality of life in EM patients, and shown no major adverse events, suggesting its potential as a prophylactic for EM.

In Vitro and In Vivo Performance of Pickering Emulsion-Based Powders of Omega-3 Polyunsaturated Fatty Acids.

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are essential nutrients for human health and have been linked to a variety of health benefits, including reducing the risk of cardiovascular diseases. In this paper, a spray-dried powder formulation based on Pickering emulsions stabilized with cellulose nanocrystals (CNC) and hydroxypropyl methylcellulose (HPMC) has been developed. The formulation was compared in vitro and in vivo to reference emulsions (conventional Self-Emulsifying Drug Delivery System, SEDDS) to formulate n-3 PUFA pharmaceutical products, specifically in free fatty acid form. The results of in vivo studies performed in fasted dogs showed that Pickering emulsions reconstituted from powders are freely available (fast absorption) with a similar level of bioavailability as reference emulsions. In the studies performed with dogs in the fed state, the higher bioavailability combined with slower absorption observed for the Pickering emulsion, compared to the reference, was proposed to be the result of the protection of the n-3 PUFAs (in free fatty acid form) against oxidation in the stomach by the solid particles stabilizing the emulsion. This observation was supported by promising results from short-term studies of chemical stability of powders with n-3 PUFA loads as high as 0.8 g oil/g powder that easily regain the original emulsion drop sizes upon reconstitution. The present work has shown that Pickering emulsions may offer a promising strategy for improving the bioavailability and stability as well as providing an opportunity to produce environmentally friendly (surfactant free) and patient-acceptable solid oral dosage forms of n-3 PUFA in the free fatty acid form.

EPA, DHA, and resolvin effects on cancer risk: The underexplored mechanisms.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements have exhibited inconsistent effects on cancer risk, and their potential efficacy as cancer preventive agents has been increasingly questioned, especially in recent large randomized clinical trials. The role of host factors that govern EPA and DHA metabolism in relation to their impact on carcinogenesis remains understudied. Resolvins, the products of EPA and DHA oxidative metabolism, demonstrate intriguing antitumorigenic effects through mechanisms such as promoting macrophage phagocytosis of cell debris and inhibiting the production of proinflammatory chemokines and cytokines by tumor-associated macrophages (TAMs), which are crucial for cancer progression. However, clinical studies have not yet shown a significant increase in target tissue levels of resolvins with EPA and DHA supplementation. 15-Lipoxygenase-1 (ALOX15), a key enzyme in EPA and DHA oxidative metabolism, is often lost in various major human cancers, including precancerous and advanced colorectal cancers. Further research is needed to elucidate whether the loss of ALOX15 expression in colorectal precancerous and cancerous cells affects EPA and DHA oxidative metabolism, the formation of resolvins, and subsequently carcinogenesis. The findings from these studies could aid in the development of novel and effective chemoprevention interventions to reduce cancer risk.

Clinical impacts of n-3 fatty acids supplementation on depression symptoms: an umbrella review of meta-analyses.

Several meta-analyses investigating the efficacy of n-3 PUFA in alleviating depression symptoms have reported conflicting findings. In the present study, we aimed to perform an umbrella meta-analysis to provide a definite conclusion. A comprehensive systematic search of PubMed, Scopus, Embase, Web of Science and Cochrane Central Library was performed up to June 2021. Meta-analysis studies evaluating the effects of n-3 PUFA on depression symptoms were included. The quality of the included meta-analyses was assessed using AMSTAR questionnaire. Out of 101 studies, twenty-two studies with twenty-six effect sizes (ES) were eligible for inclusion. Sixteen ES showed significant improving effect of n-3 supplementation on depression symptoms among which eleven ES had small ES. The other studies observed no significant effect. Available evidence suggests that n-3 PUFA (EPA, DHA) supplementation could be considered as an effective add-on therapeutic approach in relieving depression symptoms.

Erythrocyte membrane n-3 PUFA are inversely associated with breast cancer risk among Chinese women.

The relationship between erythrocyte membrane n-3 PUFA and breast cancer risk is controversial. We aimed to examine the associations of erythrocyte membrane n-3 PUFA with odds of breast cancer among Chinese women by using a relatively large sample size. A case-control study was conducted including 853 newly diagnosed, histologically confirmed breast cancer cases and 892 frequency-matched controls (5-year interval). Erythrocyte membrane n-3 PUFA were measured by GC. Logistic regression and restricted cubic spline were used to quantify the association between erythrocyte membrane n-3 PUFA and odds of breast cancer. Erythrocyte membrane α-linolenic acid (ALA), docosapentaenoic acid (DPA) and total n-3 PUFA were inversely and non-linearly associated with odds of breast cancer. The OR values (95 % CI), comparing the highest with the lowest quartile (Q), were 0·57 (0·43, 0·76), 0·43 (0·32, 0·58) and 0·36 (0·27, 0·49) for ALA, DPA and total n-3 PUFA, respectively. Erythrocyte membrane EPA and DHA were linearly and inversely associated with odds of breast cancer ((EPA: ORQ4 v. Q1 (95 % CI) = 0·59 (0·45, 0·79); DHA: ORQ4 v. Q1 (95 % CI) = 0·50 (0·37, 0·67)). The inverse associations were observed between ALA and odds of breast cancer in postmenopausal women, and between DHA and oestrogen receptor+ breast cancer. This study showed that erythrocyte membrane total and individual n-3 PUFA were inversely associated with odds of breast cancer. Other factors, such as menopause and hormone receptor status, may warrant further investigation when examining the association between n-3 PUFA and odds of breast cancer.

Comparison of high-resolution mass spectrometry acquisition methods for the simultaneous quantification and identification of per- and polyfluoroalkyl substances (PFAS).

Simultaneous identification and quantification of per- and polyfluoroalkyl substances (PFAS) were evaluated for three quadrupole time-of-flight mass spectrometry (QTOF) acquisition methods. The acquisition methods investigated were MS-Only, all ion fragmentation (All-Ions), and automated tandem mass spectrometry (Auto-MS/MS). Target analytes were the 25 PFAS of US EPA Method 533 and the acquisition methods were evaluated by analyte response, limit of quantification (LOQ), accuracy, precision, and target-suspect screening identification limit (IL). PFAS LOQs were consistent across acquisition methods, with individual PFAS LOQs within an order of magnitude. The mean and range for MS-Only, All-Ions, and Auto-MS/MS are 1.3 (0.34-5.1), 2.1 (0.49-5.1), and 1.5 (0.20-5.1) pg on column. For fast data processing and tentative identification with lower confidence, MS-Only is recommended; however, this can lead to false-positives. Where high-confidence identification, structural characterisation, and quantification are desired, Auto-MS/MS is recommended; however, cycle time should be considered where many compounds are anticipated to be present. For comprehensive screening workflows and sample archiving, All-Ions is recommended, facilitating both quantification and retrospective analysis. This study validated HRMS acquisition approaches for quantification (based upon precursor data) and exploration of identification workflows for a range of PFAS compounds.

Sex- and age-dependent associations of EPA and DHA with very short sleep duration in adults: a cross-sectional analysis.

OBJECTIVES: This study aimed to compare the efficacy of dietary intake of eicosapentaenoic acid (EPA; 20:5 ω-3) and docosahexaenoic acid (DHA; 22:6 ω-3) on very short sleep duration (<5 h/night) in adults. METHODS: The bootstrap method was used in the multinomial logistic regression to estimate the ORs and corresponding 95% confidence intervals (CIs) of very short sleep duration. We used rolling window method to analyze the effects of EPA and DHA dietary intakes on very short sleep durations in men and women over age. To illustrate the stability of the results for the selected window width, we built a shiny application. RESULTS: Compared to the first quartile, the mean ORs of EPA intake on very short sleep duration and the corresponding 95% CIs for the second, third and fourth quartiles of EPA intake among men under 32 years old were 1.50 (0.56, 3.44) mg, 1.55 (0.59, 3.48) mg, and 3.99 (1.15, 10.01) mg, respectively. Among women over 44 years old, the ORs for DHA intake were 1.12 (0.81, 1.52) mg, 0.94 (0.68, 1.29) mg, and 0.62 (0.38, 0.98) mg for the second, third and fourth quartiles, respectively. CONCLUSIONS: The associations of EPA and DHA with very short sleep duration are sex- and age-dependent. In males under the age of 32, a significant positive correlation exists between dietary EPA intake and very short sleep duration. For women above 44 years of age, an increase in DHA intake can notably ameliorate issues of very short sleep duration.

EPA and DHA Alleviated Chronic Dextran Sulfate Sodium Exposure-Induced Depressive-like Behaviors in Mice and Potential Mechanisms Involved.

Patients with ulcerative colitis (UC) have higher rates of depression. However, the mechanism of depression development remains unclear. The improvements of EPA and DHA on dextran sulfate sodium (DSS)-induced UC have been verified. Therefore, the present study mainly focused on the effects of EPA and DHA on UC-induced depression in C57BL/6 mice and the possible mechanisms involved. A forced swimming test and tail suspension experiment showed that EPA and DHA significantly improved DSS-induced depressive-like behavior. Further analysis demonstrated that EPA and DHA could significantly suppress the inflammation response of the gut and brain by regulating the NLRP3/ASC signal pathway. Moreover, intestine and brain barriers were maintained by enhancing ZO-1 and occludin expression. In addition, EPA and DHA also increased the serotonin (5-HT) concentration and synaptic proteins. Interestingly, EPA and DHA treatments increased the proportion of dominant bacteria, alpha diversity, and beta diversity. In conclusion, oral administration of EPA and DHA alleviated UC-induced depressive-like behavior in mice by modulating the inflammation, maintaining the mucosal and brain barriers, suppressing neuronal damage and reverting microbiota changes.

Reconstruction of Long-Chain Polyunsaturated Acid Synthesis Pathways in Marine Red Microalga Porphyridium cruentum Using Lipidomics and Transcriptomics.

The marine red microalga Porphyridium can simultaneously synthesize long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (C20:5, EPA) and arachidonic acid (C20:4, ARA). However, the distribution and synthesis pathways of EPA and ARA in Porphyridium are not clearly understood. In this study, Porphyridium cruentum CCALA 415 was cultured in nitrogen-replete and nitrogen-limited conditions. Fatty acid content determination, transcriptomic, and lipidomic analyses were used to investigate the synthesis of ARA and EPA. The results show that membrane lipids were the main components of lipids, while storage lipids were present in a small proportion in CCALA 415. Nitrogen limitation enhanced the synthesis of storage lipids and ω6 fatty acids while inhibiting the synthesis of membrane lipids and ω3 fatty acids. A total of 217 glycerolipid molecular species were identified, and the most abundant species included monogalactosyldiglyceride (C16:0/C20:5) (MGDG) and phosphatidylcholine (C16:0/C20:4) (PC). ARA was mainly distributed in PC, and EPA was mainly distributed in MGDG. Among all the fatty acid desaturases (FADs), the expressions of Δ5FAD, Δ6FAD, Δ9FAD, and Δ12FAD were up-regulated, whereas those of Δ15FAD and Δ17FAD were down-regulated. Based on these results, only a small proportion of EPA was synthesized through the ω3 pathway, while the majority of EPA was synthesized through the ω6 pathway. ARA synthesized in the ER was likely shuttled into the chloroplast by DAG and was converted into EPA by Δ17FAD.

Co-designing Entrustable Professional Activities in General Practitioner's training: a participatory research study.

BACKGROUND: In medical education, Entrustable Professional Activities (EPAs) have been gaining momentum for the last decade. Such novel educational interventions necessitate accommodating competing needs, those of curriculum designers, and those of users in practice, in order to be successfully implemented. METHODS: We employed a participatory research design, engaging diverse stakeholders in designing an EPA framework. This iterative approach allowed for continuous refinement, shaping a comprehensive blueprint comprising 60 EPAs. Our approach involved two iterative cycles. In the first cycle, we utilized a modified-Delphi methodology with clinical competence committee (CCC) members, asking them whether each EPA should be included. In the second cycle, we used semi-structured interviews with General Practitioner (GP) trainers and trainees to explore their perceptions about the framework and refine it accordingly. RESULTS: During the first cycle, 14 CCC members agreed that all the 60 EPAs should be included in the framework. Regarding the formulation of each EPAs, 20 comments were given and 16 adaptations were made to enhance clarity. In the second cycle, the semi-structured interviews with trainers and trainees echoed the same findings, emphasizing the need of the EPA framework for improving workplace-based assessment, and its relevance to real-world clinical scenarios. However, trainees and trainers expressed concerns regarding implementation challenges, such as the large number of EPAs to be assessed, and perception of EPAs as potentially high-stakes. CONCLUSION: Accommodating competing stakeholders' needs during the design process can significantly enhance the EPA implementation. Recognizing users as experts in their own experiences empowers them, enabling a priori identification of implementation barriers and potential pitfalls. By embracing a collaborative approach, wherein diverse stakeholders contribute their unique viewpoints, we can only create effective educational interventions to complex assessment challenges.

Escaping malnutrition by shifting habitats: A driver of three-spined stickleback invasion in Lake Constance.

Fatty acids, and especially long-chain polyunsaturated fatty acids, are biologically important components in the metabolism of vertebrates, including fish. Essential fatty acids (EFA) are those that in a given animal cannot be synthesized or modified from precursors and must therefore be acquired via the diet. Because EFAs are often unevenly distributed in nature, this requirement may drive species to make behavioral or ecological adaptations to avoid malnutrition. This is especially true for fish like the three-spined stickleback (Gasterosteus aculeatus L.) of Upper Lake Constance (ULC), whose recent marine ancestors evolved with access to EFA-rich prey, but which found themselves in an EFA-deficient habitat. An unexpected and unprecedented ecological shift in the ULC stickleback population from the littoral to pelagic zones in 2012 might be linked to EFA availability, triggering ecological release and enabling them to build a hyperabundant population while displacing the former keystone species, the pelagic whitefish Coregonus wartmanni. To test this hypothesis, sticklebacks from the littoral and pelagic zones of ULC were sampled seasonally in two consecutive years, and their stomach contents and fatty acid profiles were analysed. Pelagic sticklebacks were found to possess significantly higher values of an important EFA, docosahexaenoic acid (DHA), especially during autumn. Evaluation of the DHA supply suggests that sticklebacks feeding in the littoral zone during autumn could not meet their DHA requirement, whereas DHA availability in the pelagic zone was surplus to demand. During autumn, pelagic sticklebacks consumed large amounts of DHA-rich prey, that is, copepods, whereas littoral sticklebacks relied mainly mostly on cladocerans, which provide much lower quantities of DHA. Access to pelagic zooplankton in 2012 was possibly facilitated by low densities of previously dominant zooplanktivorous whitefish. The present study offers a convincing physiological explanation for the observed expansion of invasive sticklebacks from the littoral to the pelagic zones of Lake Constance, contributing to a phase shift with severe consequences for fisheries.

Beneficial Impact of Eicosapentaenoic Acid on the Adverse Effects Induced by Palmitate and Hyperglycemia on Healthy Rat Chondrocyte.

Osteoarthritis (OA) is the most prevalent form of arthritis and a major cause of pain and disability. The pathology of OA involves the whole joint in an inflammatory and degenerative process, especially in articular cartilage. OA may be divided into distinguishable phenotypes including one associated with the metabolic syndrome (MetS) of which dyslipidemia and hyperglycemia have been individually linked to OA. Since their combined role in OA pathogenesis remains to be elucidated, we investigated the chondrocyte response to these metabolic stresses, and determined whether a n-3 polyunsaturated fatty acid (PUFA), i.e., eicosapentaenoic acid (EPA), may preserve chondrocyte functions. Rat chondrocytes were cultured with palmitic acid (PA) and/or EPA in normal or high glucose conditions. The expression of genes encoding proteins found in cartilage matrix (type 2 collagen and aggrecan) or involved in degenerative (metalloproteinases, MMPs) or in inflammatory (cyclooxygenase-2, COX-2 and microsomal prostaglandin E synthase, mPGES) processes was analyzed by qPCR. Prostaglandin E2 (PGE2) release was also evaluated by an enzyme-linked immunosorbent assay. Our data indicated that PA dose-dependently up-regulated the mRNA expression of MMP-3 and -13. PA also induced the expression of COX-2 and mPGES and promoted the synthesis of PGE2. Glucose at high concentrations further increased the chondrocyte response to PA. Interestingly, EPA suppressed the inflammatory effects of PA and glucose, and strongly reduced MMP-13 expression. Among the free fatty acid receptors (FFARs), FFAR4 partly mediated the EPA effects and the activation of FFAR1 markedly reduced the inflammatory effects of PA in high glucose conditions. Our findings demonstrate that dyslipidemia associated with hyperglycemia may contribute to OA pathogenesis and explains why an excess of saturated fatty acids and a low level in n-3 PUFAs may disrupt cartilage homeostasis.

Monitoring landfill volatile organic compounds emissions by an uncrewed aerial vehicle platform with infrared and visible-light cameras, remote monitoring, and sampling systems.

An uncrewed aerial vehicle (UAV) platform equipped with dual imaging cameras, a gas sampling system, and a remote synchronous monitoring system was developed to sample and analyze volatile organic compounds (VOCs) emitted from landfills. The remote synchronous monitoring system provided real-time video to administrators with specific permissions to assist in identifying sampling sites within extensive landfill areas. The sampling system included four kits capable of collecting samples from different locations during a single flight mission. Each kit comprised a 1 L Tedlar bag for measuring landfill VOC concentrations according to the TO-15 method prescribed by the US Environmental Protection Agency. The air sample was introduced into a Tedlar bag via pumping. A known volume of the sample was subsequently concentrated using a solid multisorbent concentrator. Following this, the sample underwent cold trap concentration and thermal desorption. The concentrated sample was then transferred to a chromatography-mass spectrometry system for separation and analysis. Since the anaerobic catabolism of organic waste is exothermic and emits VOCs, this study employed UAV thermal imaging to locate principal emission sources for sampling. Visible-light imaging helped identify newer or older landfill sections, aiding in the selection of appropriate sampling sites, particularly when surfaces were thermally disturbed by solar radiation. Field measurements were conducted under three meteorological conditions: sunny morning, cirrus morning, and thin cloud evening (2 h after sunset), identifying 119, 122, and 111 chemical species respectively. The sequence of total VOC concentrations measured correlated with the meteorological conditions as follows: cirrus morning > thin cloud evening > sunny morning. The results indicated that ambient temperature and global solar radiation significantly influenced daytime gas emissions from landfills. Evening thermal images, unaffected by solar heating, facilitated more accurate identification of major VOC emission points, resulting in higher VOC concentrations compared to those recorded in the sunny morning. VOCs from the landfill were categorized into nine organic groups: alkanes, alkenes, carbonyls, aromatics, alcohols, esters, ethers, organic oxides, and others. The classification was based on carbon-containing compounds (Cn, where the compound contains n carbon atoms). Alkanes were predominant in terms of Cn presence, followed by alcohols and carbonyls. Among the organic groups, organic oxides, particularly 2-heptyl-1,3-dioxolane, exhibited the highest concentrations, succeeded by alkenes. Sampling under cloudy conditions or in the evening is recommended to minimize the effects of surface temperature anomalies caused by solar radiation, which vary due to differences in land composition.