TL;DR: The consumption of linoleic acid (LA, ω-6 18:2), the most common PUFA in the Modern Western diet (MWD), has significantly increased over the last century in tandem with unprecedented incidence of chronic metabolic diseases like obesity and type 2 diabetes mellitus (T2DM) as discussed by the authors.
Abstract: The consumption of linoleic acid (LA, ω-6 18:2), the most common ω-6 polyunsaturated fatty acid (PUFA) in the Modern Western diet (MWD), has significantly increased over the last century in tandem with unprecedented incidence of chronic metabolic diseases like obesity and type 2 diabetes mellitus (T2DM). Although an essential fatty acid for health, LA was a very rare fatty acid in the diet of humans during their evolution. While the intake of other dietary macronutrients (carbohydrates like fructose) has also risen, diets rich in ω-6 PUFAs have been promoted in an effort to reduce cardiovascular disease despite unclear evidence as to how increased dietary LA consumption could promote a proinflammatory state and affect glucose metabolism. Current evidence suggests that sex, genetics, environmental factors, and disease status can differentially modulate how LA influences insulin sensitivity and peripheral glucose uptake as well as insulin secretion and pancreatic beta-cell function. Therefore, the aim of this review will be to summarize recent additions to our knowledge to refine the unique physiological and pathophysiological roles of LA in the regulation of glucose homeostasis.
TL;DR: A robust effect of EPA 4 g/d supplementation in increasing plasma EPA and 18-HEPE levels is shown, associated with improved conversion to RvE2-3, and LXB4 levels.
Abstract: Background Eicosapentaenoic acid (EPA) supplementation is an effective treatment option in major depressive disorder (MDD) associated with chronic low-grade inflammation. EPA is the precursor of specialized pro-resolving lipid mediators (SPMs) termed resolvins (Rv), that serve important roles in the resolution of inflammation. The objective of this study was to assess the effects of different doses of EPA on plasma concentrations of EPA metabolites and SPMs in MDD patients. Methods In a 2-site study, 61 MDD patients with body mass index >25 kg/m2 and serum high-sensitivity C-reactive protein ≥3 μg/mL were enrolled in a 12-week randomized trial comparing EPA 1, 2, and 4 g/d to placebo. Plasma EPA (mol%) and SPMs (pg/mL) were measured in 42 study completers at baseline and at the end of treatment by liquid chromatography/mass spectrometry. Results Plasma EPA and SPM concentrations did not change in the placebo group during 12 weeks of treatment. Plasma EPA and EPA-derived metabolites increased significantly and dose-dependently in all EPA supplementation arms. The increase in 18-hydroxyeicosapentaenoic acid (18-HEPE), the precursor of RvE1–3, was significantly greater with the 4 g/d EPA dose than the other doses from week 4 to 12. RvE1 was undetected in all treatment groups, while RvE2 was detected in half of the subjects both at baseline and after treatment, with dose-dependent increases. RvE3 was detected only after supplementation, dose-dependently. A significant reduction in plasma arachidonic acid (AA), relative to baseline, was observed in all EPA arms. This was in contrast with an increase in AA-derived SPM lipoxin B4 (LXB4) in the 4 g/d arm. Conclusions Our results show a robust effect of EPA 4 g/d supplementation in increasing plasma EPA and 18-HEPE levels, associated with improved conversion to RvE2–3, and LXB4 levels.
TL;DR: In this article, the effects of different omega-3 fatty acid (eicosapentaenoic acid, DHA, and arachidonic acid (AA) on the bioavailability of nitric oxide (NO) and fatty acid composition in human umbilical vein endothelial cells (HUVECs) were compared.
Abstract: Treatment with high dose icosapent ethyl (IPE), an ethyl ester of the omega-3 fatty acid eicosapentaenoic acid (EPA), significantly reduced ischemic events in patients with either cardiovascular disease (CV) or diabetes plus other risk factors (REDUCE-IT) but the mechanism is not well understood. We compared the effects of EPA, docosahexaenoic acid (DHA), and the omega-6 fatty acid arachidonic acid (AA) on bioavailability of nitric oxide (NO) and fatty acid composition. Human umbilical vein endothelial cells (HUVECs) were pretreated with EPA, DHA, or AA (10 µM). Cells were stimulated with calcium ionophore and NO and peroxynitrite (ONOO-) were measured using porphyrinic nanosensors. Levels of EPA, DHA, AA and other fatty acids were measured by gas chromatography (GC). EPA treatment caused the greatest NO release (18%, p < 0.001) and reduction in ONOO- (13%, p < 0.05) compared to control; the [NO]/[ ONOO-] ratio increased by 35% (p < 0.001). DHA treatment increased NO levels by 12% (p < 0.01) but had no effect on ONOO- release. AA did not affect either NO or ONOO- release. Fatty acid treatments increased their respective levels in endothelial cells. EPA levels increased 10-fold to 4.59 mg/g protein (p < 0.001) with EPA treatment and the EPA/AA ratio increased by 10-fold (p < 0.001) compared to vehicle. Only EPA increased docosapentaenoic acid (DPA, omega-3) levels by 2-fold (p < 0.001). AA alone decreased the EPA/AA ratio 4-fold (p<0.001). These findings support a preferential benefit of EPA on endothelial function and omega-3 fatty acid content.
TL;DR: The role of fatty acids in amplifying or reducing inflammation seems to be also reflected in PAF metabolism, as shown in patterns of RBC fatty acids.
Abstract: Introduction Platelet-activating-factor is an inflammatory lipid mediator. Key enzymes of its biosynthesis are CDP-choline:1-alkyl-2-acetyl-sn-glycerol-cholinephosphotransferase (PAF-CPT) and acetyl-CoA:lyso-PAF-acetyltransferases (Lyso-PAF-AT) while PAF-AH/Lp-PLA2 degrade PAF. The interplay between PAF and fatty acids metabolism was explored. Material and methods In a healthy population, PAF levels, its metabolic enzymes activity and RBC fatty acids were measured while desaturases indices (D) were estimated. A principal component analysis was also applied to assess patterns of RBC fatty acids. Results SFA were related to increased PAF biosynthesis and decreased Lp-PLA2 only in women. MUFA were inversely associated with PAF biosynthesis and positively with Lp-PLA2. Omega-6 fatty acids were positively correlated only with PAF-CPT while no significant correlations were observed with n3 fatty acids. D6 index was positively related with PAF biosynthetic enzymes and inversely with Lp-PLA2 while D9 correlated positively with Lp-PLA2. The pattern of high MUFA and low n6 was associated with reduced PAF biosynthesis and/or increased catabolism in both sexes. Conclusion The role of fatty acids in amplifying or reducing inflammation seems to be also reflected in PAF metabolism.
TL;DR: In this paper, a meta-analysis of observational studies on maternal and fetal fatty acid metabolism, published until May 2021, was performed to compare levels of linoleic acid, α-linolenic acid (ALA), arachidonic acid (AA), docosahexaenoic acid(DHA), and total n-3 and n-6 PUFA between mothers with and without Gestational Diabetes mellitus and their fetuses.
Abstract: Background Polyunsaturated fatty acid (PUFA) is important for the development of the fetal brain, and the retina. Gestational diabetes mellitus (GDM) may influence maternal and fetal fatty acid metabolism, in turn affecting fetal growth and development. In several studies, maternal and fetal PUFA metabolic differences have been reported between mothers with and without GDM, but not in other studies. Thus, the aim of this meta-analysis (registration number: CRD42020220448) was to compare levels of linoleic acid (LA), α-linolenic acid (ALA), arachidonic acid (AA), docosahexaenoic acid (DHA), and total n-3 and n-6 PUFA between mothers with and without GMD and their fetuses. Methods We performed a meta-analysis of observational studies on maternal and fetal fatty acid metabolism, published until May 2021. In addition, we performed subgroup analysis depending on the analyzed tissues (plasma/serum, erythrocyte membrane, or placenta) and the expression modes of fatty acids (concentration or percentage). Results We included 24 observational studies involving 4335 maternal datasets and 12 studies involving 1675 fetal datasets in the meta-analysis. Levels of AA, DHA, and n-6 and n-3 PUFA were lower in the cord blood of mothers with GDM than in controls (P Conclusions GDM appears to influence the transfer of PUFAs from mothers to fetuses. The percentage of PUFAs in maternal plasma/serum was higher, and that in erythrocyte membranes was lower in mothers with GDM compared to those with normal glucose tolerance.
TL;DR: In this paper, the individual fatty acid (FA) content of matched plasma and serum samples in both absolute (μg/mL) and relative percent (%) composition was analyzed using archived fasted morning samples from the Florey Adelaide Male Ageing Study (FAMAS).
Abstract: Measuring fatty acid (FA) levels in blood as a risk factor for chronic disease has been studied extensively. Previous research has used either plasma or serum samples to examine these associations. However, whether results from plasma and serum samples can be compared remains unclear, as differences in methodology related to the separation of plasma and serum from whole blood may impact FA levels. This study analyzed the individual FA content of matched plasma and serum samples in both absolute (μg/mL) and relative percent (%) composition. Analyses were performed using archived fasted morning samples from the Florey Adelaide Male Ageing Study (FAMAS). Matched plasma and serum samples were available from 98 male subjects aged 40–85. Total FA were analyzed by gas-liquid chromatography equipped with a flame ionization detector (GLC-FID). Analyses comprised of over 60 FA including major FA such as Palmitic Acid (PA), Palmitoleic acid (POA), Stearic Acid (SA), Oleic Acid (OA), Linoleic Acid (LNA), alpha-linolenic acid (ALA), Eicosapentaenoic acid (EPA), Arachidonic Acid (ARA), and Docosahexaenoic acid (DHA). Differences between groups was determined by t-test. Correlation and Bland-Altman analyses were also performed to examine the relationship between plasma and serum samples. There were no significant differences between major plasma and serum fatty acids expressed in μg/mL and relative % composition. Correlation analysis determined a strong and significantly positive association (r ≥ 0.65, p
TL;DR: African Americans have higher levels of AA and a higher prevalence of GG allele compared to whites, 81% vs 43%, respectively, and increased consumption of n-6 PUFA and LA resulting in increased AA and subsequent inflammation may be fueling increased prevalence of chronic diseases especially in African descent.
Abstract: Numerous studies have reported an association between genetic variants in fatty acid desaturases (FADS1 and FADS2) and plasma or erythrocyte long chain polyunsaturated fatty acid (PUFA) levels. Increased levels of n-6 PUFAs have been associated with inflammation and several chronic diseases, including diabetes and cancer. We hypothesized that genetic variants of FADS that more efficiently convert precursor n-6 PUFA to arachidonic acid (AA) may explain the higher burden of chronic diseases observed in African Americans. To test this hypothesis, we measured the level of n-6 and n-3 PUFAs in erythrocyte membrane phospholipids and genotyped the rs174537 FADS variants associated with higher AA conversion among African American and European American populations. We included data from 1,733 individuals who participated in the Tennessee Colorectal Polyp Study, a large colonoscopy-based case-control study. Erythrocyte membrane PUFA percentages were measured using gas chromatography. Generalized linear models were used to estimate association of race and genotype on erythrocyte phospholipid membrane PUFA levels while controlling for self-reported dietary intake. We found that African Americans have higher levels of AA and a higher prevalence of GG allele compared to whites, 81% vs 43%, respectively. Homozygous GG genotype was negatively associated with precursor PUFAs (linoleic [LA], di-homo-γ-linolenic [DGLA]), positively associated with both product PUFA (AA, docosahexaenoic acid [DHA]), product to precursor ratio (AA to DGLA), an indirect measure of FADs efficiency and increased urinary isoprostane F2 (F2-IsoP) and isoprostane F3 (F3-IsoP), markers of oxidative stress. Increased consumption of n-6 PUFA and LA resulting in increased AA and subsequent inflammation may be fueling increased prevalence of chronic diseases especially in African descent.
TL;DR: One of the great unanswered biological questions is the absolute necessity of the polyunsaturated lipid docosahexaenoic acid (DHA; 22:6n-3) in retinal and neural tissues.
Abstract: One of the great unanswered biological questions is the absolute necessity of the polyunsaturated lipid docosahexaenoic acid (DHA; 22:6n-3) in retinal and neural tissues. Everything from the simple eye spot of dinoflagellates to cephalopods to every class of vertebrates uses DHA, yet it is abundant only in cold water marine food chains. Docosapentaenoic acids (DPAs; 22:5n-6 and especially 22:5n-3) are fairly plentiful in food chains yet cannot substitute for DHA. About 600 million years ago, multi-cellular, air breathing systems evolved rapidly and 32 phyla came into existence in a short geological time span; the “Cambrian Explosion”. Eukaryotic intracellular detail requires cell membranes, which are constructed of complex lipids, and proteins. Proteins and nucleic acids would have been abundant during the first 2.5–5 billion years of anaerobic life but lipids, especially unsaturated fatty acids, would not. We hypothesize lipid biology was a key driver of the Cambrian Explosion, because it alone provides for compartmentalization and specialization within cells DHA has six methylene interrupted double bonds providing controlled electron flow at precise energy levels; this is essential for visual acuity and truthful execution of the neural pathways which make up our recollections, information processing and consciousness. The last double bond is critical for the evolution and function of the photoreceptor and neuronal and synaptic signaling systems. It completes a quantum mechanical device for the regulation of current flow with absolute signal precision based on electron tunneling (ET). DHA's methylene interruption distance is The molecular biophysical foundation of neural signaling can also include the discrete pattern of paired spin states that arise in the DHA double bond and methylene regions. The complexity depends upon the number of C13 and H1 molecular sites in which spin states are coupled. Electron wave harmonics with entanglement and cohesion provide a mechanism for learning and memory, and power cognition and complex human brain functions.
TL;DR: The results of randomized controlled trials (RCTs) investigating supplemental n-3 polyunsaturated fatty acids (PUFA) on muscle mass and function have been inconsistent.
Abstract: The results of randomized controlled trials (RCTs) investigating supplemental n-3 polyunsaturated fatty acids (PUFA) on muscle mass and function have been inconsistent. The present study aimed to quantitatively evaluate the effect of n-3 PUFA supplementation on indicators of muscle mass and function in healthy subjects. A systematic literature search was conducted up to July 2020 with databases of PubMed and Web of science. The random-effects model was implemented to calculate the weighted mean difference of net change of indicators regarding muscle mass and function. A total of nine studies (thirteen treatment groups) with 2067 participants were included for data analysis. The summary estimate showed that n-3 PUFA supplementation significantly increased the grip strength (1.17 kg; 95% CI: 0.27, 2.08 kg). Non-significant effect was observed with respect to muscle mass parameters, including fat mass (-0.67 kg; 95% CI: -2.20, 0.87 kg) and lean mass (0.33 kg; 95% CI: -0.35, 1.00 kg). Regarding muscle function indicators, there were non-significant effects on walking speed (-0.01 m•s−1; 95% CI: -0.03, 0.01 m•s−1), time up and go test (-0.25 s; 95% CI: -0.55, 0.04 s), respectively. The findings of this study indicated that supplementation with n-3 PUFA might have beneficial effects to improve muscle mass and function in healthy participants. However, there was no significant improvement in the subjects' muscle mass. Whether n-3 PUFA supplementation has favorable effects in participants with sarcopenia are warranted to be further investigated.
TL;DR: In this article, the use of acellular fish skin grafts (FSG) for the treatment of burn wounds is becoming more common due to its beneficial wound healing properties.
Abstract: The use of acellular fish skin grafts (FSG) for the treatment of burn wounds is becoming more common due to its beneficial wound healing properties. In our previous study we demonstarted that FSG is a scaffold biomaterial that is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) conjugated to phosphatidylcholines. Here we investigated whether EPA and DHA derived lipid mediators are influenced during the healing of burn wounds treated with FSG. Deep partial and full thickness burn wounds (DPT and FT, respectively) were created on Yorkshire pigs (n = 4). DPT were treated with either FSG or fetal bovine dermis while FT were treated either with FSG or cadaver skin initially and followed by a split thickness skin graft. Punch biopsies were collected on days 7, 14, 21, 28 and 60 and analyzed in respect of changes to approximately 45 derivatives of EPA, DHA, arachidonic acid (AA), and linoleic acid (LA) employing UPLC-MS/MS methodology. Nine EPA and DHA lipid mediators, principally mono-hydroxylated derivatives such as 18-HEPE and 17-HDHA, were significantly higher on day 7 in the DPT when treated with FSG. A similar but non-significant trend was observed for the FT. The results suggest that the use of FSG in burn wound treatment can alter the formation of EPA and DHA mono hydroxylated lipid mediators in comparison to other grafts of mammalian origin. The differences observed during the first seven days after treatment indicates that FSG affects the early stages of wound healing.
TL;DR: The literature review suggests that fatty acid analyses could potentially provide a valuable source of data to further inform the pathology and progression of AD.
Abstract: Alzheimer's disease (AD) is a complex and heterogeneous neurodegenerative disease. A wide range of techniques have been proposed to facilitate early diagnosis of AD, including biomarkers from the cerebrospinal fluid and blood. Although phosphorylated tau and amyloid beta are amongst the most promising biomarkers of AD, other peripheral biomarkers have been identified and in this review we synthesize the current knowledge on circulating fatty acids. Fatty acids are involved in different biological process including neurotransmission and inflammation. Interestingly, some fatty acids appear to be modulated during disease progression, including long chain saturated fatty acids, and polyunsaturated fatty acids, such as docosahexaenoic acid . However, discrepant results have been reported in the literature and there is the need for further validation and method standardization. Nonetheless, our literature review suggests that fatty acid analyses could potentially provide a valuable source of data to further inform the pathology and progression of AD.
TL;DR: A detailed review of the role of PUFAs, diet and genotype in risk for cardiovascular diseases is presented in this paper, where the authors also discuss the importance of PUFA genes in the onset and progression of various metabolic conditions.
Abstract: Polyunsaturated fatty acids (PUFAs) are long chain fatty acids that are characterized by the presence of more than one double bond. These include fatty acids such as ꞷ-3-α-linolenic acid (ALA) and ꞷ-6 –linoleic acid (LA) which can only be obtained from dietary sources and are therefore termed essential fatty acids. They contain the building blocks for dihomo-γ-linolenic acid and arachidonic acid in the ꞷ-6 family as well as eicosapentaenoic acid and docosahexaenoic acid in the ꞷ-3 family. Both ALA and LA are important constituents of animal and plant cell membranes and are important components of anti-inflammatory and pro-inflammatory hormones and therefore, often modulate cellular immunity under chronic inflammatory states. The variation in physiological PUFA levels is under significant genetic influence, the fatty acid desaturase (FADS) genes being key regulators of PUFA metabolism. The variants in these genes have been shown to alter fatty acid metabolism and influence the onset and progression of various metabolic conditions. This detailed review discusses the role of PUFAs, diet and genotypes in risk for cardiovascular diseases.
TL;DR: Oleoylethanolamide (OEA), a well-known satiety factor, is produced during feeding in the proximal intestine, where enterocytes sense oleic acid in dietary fat via CD36 and convert it to OEA through NAPE-PLD dependent or independent pathways as mentioned in this paper.
Abstract: Oleoylethanolamide (OEA), a well-known satiety factor, is produced during feeding in the proximal intestine. Enterocytes sense oleic acid in dietary fat via CD36 and convert it to OEA through NAPE-PLD dependent or independent pathways. The satiety function of OEA is known to involve peroxisome proliferator-activated receptor type-α (PPAR-α). OEA stimulates afferent sensory fibers (possibly those of the vagus nerve) and provoke the recruitment of feeding-controlling circuits in the brain that use oxytocin and histamine as neurotransmitters for regulating satiety. Dysfunction of OEA synthesis by high-fat feeding might contribute to increased weight and obesity. Here, we describe the roles played by OEA in the regulation of energy metabolism and food intake by introducing our preliminary data regarding this lipid mediator, and we briefly outline the biosynthesis and deactivation of OEA.
TL;DR: In this article, the authors compared mouse HL-1 cardiomyocytes, isolated adult rat Cardiomyocyte, human embryonic stem cell-derived cardiocyte (hESC-CMs) and human induced pluripotent stem cells (hiPSC)-CMs for the study of metabolic aspects of cardiac functioning in health and disease.
Abstract: Isolated or cultured cells have proven to be valuable model systems to investigate cellular (patho)biology and for screening of the efficacy of drugs or their possible side-effects. Pluripotent stem cells (PSC) can be readily obtained from healthy individuals as well as from diseased patients, and protocols have been developed to differentiate these cells into cardiomyocytes. Hence, these cellular models are moving center stage for a broader application. In this review, we focus on comparing mouse HL-1 cardiomyocytes, isolated adult rat cardiomyocytes, human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) for the study of metabolic aspects of cardiac functioning in health and disease. Various studies have reported that these cellular models are suitable for assessing substrate uptake and utilization, in that each display an adequate and similar response to physiological triggers, in particular the presence of insulin. Likewise, disease conditions, such as excess lipid supply, similarly affect each of these rodent and human cardiomyocyte models. It is concluded that PSC-CMs obtained from patients with cardiogenetic abnormalities are promising models to evaluate the functional consequence of gene variants with unknown significance.
TL;DR: Letrozole restores Δ6-desaturase mediated synthesis of the anti-inflammatory PGE1-precursor DGLA in vitro and is the first endocrine-active agent to have opposing effects on FADS1 and FADS2 catalyzed activities.
Abstract: Purpose Plasticity in fatty acid metabolism is increasingly recognized as a major feature influencing cancer progression and efficacy of treatments. Estrogen receptor positive MCF7 human breast cancer cells have long been known to have no FADS2-mediated Δ6-desaturase activity. Our objective was to examine the effect of estrogen and the “antiestrogen” aromatase inhibitor letrozole, on Δ5- and Δ6-desaturase synthesized fatty acids in vitro. Methods Eicosa-11,14-dienoic acid (20:2n-6), a known substrate for both FADS1 and FADS2, was used as a sentinel of relative FADS2 and FADS1 activity. MCF7 cells and four additional estrogen responsive wild type cell lines (HepG2, SK-N-SH, Y79 and Caco2) were studied. FAME were quantified by GC-FID and structures identified by GC CACI-MS/MS. Results In all five cell lines, estrogen caused a dose dependent decrease in sciadonic acid (5,11,14–20:3, ScA) via apparent inhibition of FADS1 activity, and had no effect on FADS2 catalyzed synthesis of dihomo-gamma linolenic acid (8,11,14–20:3; DGLA). In MCF7 cells, letrozole caused a dose dependent increase in FADS2-catalyzed DGLA synthesis, which plateaued in SK-N-SH cells. Conclusion Letrozole restores Δ6-desaturase mediated synthesis of the anti-inflammatory PGE1-precursor DGLA in vitro and is the first endocrine-active agent to have opposing effects on FADS1 and FADS2 catalyzed activities.
TL;DR: In this article, the role of omega-3 (n3) fatty acids and low-dose aspirin in the primary prevention of ischemic cardiovascular disease (CVD) are controversial.
Abstract: Background The roles of omega-3 (n3) fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and low-dose aspirin in the primary prevention of ischemic cardiovascular disease (CVD) are controversial. Since omega-3 (n3) fatty acids and aspirin affect cyclooxygenase activity in platelets, there could be a clinically-relevant effect of aspirin combined with a particular n3 fatty acid level present in each individual. Methods RBC EPA+DHA, arachidonic acid (AA) and docosapentaenoic acid (DPA) were measured in 2500 participants without known CVD in the Framingham Heart Study. We then tested for interactions with reported aspirin use (1004 reported use and 1494 did not) on CVD outcomes. The median follow-up was 7.2 years. Results Having RBC EPA+DHA in the second quintile (4.2–4.9% of total fatty acids) was associated with significantly reduced risk for future CVD events (relative to the first quintile, Conclusions There is a complex interaction between aspirin use and RBC EPA+DHA levels on CVD outcomes. This suggests that aspirin use may be beneficial in one omega-3 environment but harmful in another, implying that a personalized approach to both aspirin use and omega-3 supplementation may be needed.
TL;DR: The study will provide information regarding the effects of ALA and DHA supplementation on oxylipin profiles in obese but otherwise healthy females and improve the understanding of the response of circulating inflammatory mediators originating from immune cells, adipose tissue and the liver to n-3 PUFA supplementation in relation to the metabolic features of obesity.
Abstract: Introduction Consumption of omega-3 polyunsaturated fatty acids (n-3 PUFAs) has been reported to provide health benefits, but it remains unknown whether the fatty acids themselves or their oxygenated metabolites, oxylipins, are responsible for the beneficial effects. Purpose This paper describes the design and rationale of a randomized, double-blinded, cross-over study comparing the effects of α-linolenic acid (ALA)-rich flax oil and docosahexaenoic acid (DHA)-rich fish oil supplementation on circulating oxylipin profiles in females with obesity, in relation to obesity-induced inflammation. Methods and analysis Pre-menopausal females (n = 24) aged 20-55 with a BMI ≥30, will consume capsules containing flaxseed oil (4 g ALA/day) or fish oil (4 g DHA + 0.8 g EPA/day) during 4-week supplementation phases, with a minimum 4-week washout. The primary outcome is alterations in plasma oxylipin profiles. Secondary outcomes include effects of supplementation on circulating markers of inflammation, adipokines, plasma fatty acid composition, blood lipid profile, anthropometrics, oxylipin and cytokine profiles of stimulated immune cells, monocyte glucose metabolism, blood pressure and pulse wave velocity. Ethics and significance This trial has been approved by the University of Manitoba Biomedical Research Ethics Board and the St. Boniface Hospital Research Review Committee. The study will provide information regarding the effects of ALA and DHA supplementation on oxylipin profiles in obese but otherwise healthy females. Additionally, it will improve our understanding of the response of circulating inflammatory mediators originating from immune cells, adipose tissue and the liver to n-3 PUFA supplementation in relation to the metabolic features of obesity.
TL;DR: In this paper, the contribution of genetic and environmental influences on lipid mediators involved in the regulation of inflammation and energy metabolism was determined. But, the authors did not identify the factors contributing to biological variation in lipid mediator.
Abstract: Lipid bioactivity is a result of direct action and the action of lipid mediators including oxylipins, endocannabinoids, bile acids and steroids. Understanding the factors contributing to biological variation in lipid mediators may inform future approaches to understand and treat complex metabolic diseases. This research aims to determine the contribution of genetic and environmental influences on lipid mediators involved in the regulation of inflammation and energy metabolism. This study recruited 138 monozygotic (MZ) and dizygotic (DZ) twins aged 18–65 years and measured serum oxylipins, endocannabinoids, bile acids and steroids using liquid chromatography mass-spectrometry (LC-MS). In this classic twin design, the similarities and differences between MZ and DZ twins are modelled to estimate the contribution of genetic and environmental influences to variation in lipid mediators. Heritable lipid mediators included the 12-lipoxygenase products 12-hydroxyeicosatetraenoic acid [0.70 (95% CI: 0.12,0.82)], 12-hydroxyeicosatetraenoic acid [0.73 (95% CI: 0.30,0.83)] and 14‑hydroxy-docosahexaenoic acid [0.51 (95% CI: 0.07,0.71)], along with the endocannabinoid docosahexaenoy-lethanolamide [0.52 (95% CI: 0.15,0.72)]. For others such as 13-hydroxyoctadecatrienoic acid and lithocholic acid the contribution of environment to variation was stronger. With increased understanding of lipid mediator functions in health, it is important to understand the factors contributing to their variance. This study provides a comprehensive analysis of lipid mediators and extends pre-existing knowledge of the genetic and environmental influences on the human lipidome.
TL;DR: In this paper, a 10-week controlled feeding study was conducted to investigate the relationship between maternal red blood cell (RBC) and breast milk DHA levels and to provide insight into the sufficiency of DHA recommendations during lactation.
Abstract: Background The importance of providing the newborn infant with docosahexaenoic acid (DHA) from breast milk is well established. However, women in the United States, on average, have breast milk DHA levels of 0.20%, which is below the worldwide average (and proposed target) of >0.32%. Additionally, the relationship between maternal red blood cell (RBC) and breast milk DHA levels may provide insight into the sufficiency of DHA recommendations during lactation. Whether the standard recommendation of at least 200 mg/day of supplemental DHA during lactation is sufficient for most women to achieve a desirable RBC and breast milk DHA status is unknown. Methods Lactating women (n = 27) at about 5 weeks postpartum were enrolled in a 10–12 week controlled feeding study that included randomization to 480 or 930 mg choline/d (diet plus supplementation). As part of the intervention, all participants were required to consume a 200 mg/d of microalgal DHA. RBC and breast milk DHA levels were measured by capillary gas chromatography in an exploratory analysis. Results Median RBC DHA was 5.0% (95% CI: 4.3, 5.5) at baseline and 5.1% (4.6, 5.4) after 10 weeks of supplementation (P = 0.6). DHA as a percent of breast milk fatty acids increased from 0.19% (0.18, 0.33) to 0.34% (0.27, 0.38) after supplementation (P 5% was unchanged (52% at baseline and week 10). The proportion of women achieving a breast milk DHA level of >0.32% approximately doubled from 30% to 56% (p = 0.06). Baseline RBC and breast milk DHA levels affected their responses to supplementation. Those with baseline RBC and breast milk DHA levels above the median (5% and 0.19%, respectively) experienced no change or a slight decrease in levels, while those below the median had a significant increase. Choline supplementation did not significantly influence final RBC or breast milk DHA levels. Conclusions On average, the standard prenatal DHA dose of 200 mg/d did not increase RBC DHA but did increase breastmilk DHA over 10 weeks in a cohort of lactating women in a controlled-feeding study. Baseline DHA levels in RBC and breast milk affected the response to DHA supplementation, with lower levels being associated with a greater increase and higher levels with no change or a slight decrease. Additional larger, dose-response DHA trials accounting for usual intakes and baseline DHA status are needed to determine how to best achieve target breast milk DHA levels and to identify additional modifiers of the variable breast milk DHA response to maternal DHA supplementation.
TL;DR: The additive effects of prostaglandin (PG)-EP2 agonists on a PG-FP agonist toward adipogenesis in two- or three-dimensional (2D or 3D) cultures of 3T3-L1 cells was examined by lipid staining, the mRNA expression of adipogenesis related genes, and extracellular matrixes (ECMs) including collagen molecules (Col) -1, -4 and -6, and fibronectin (Fn), as measured by a micro-squeezer as mentioned in this paper.
Abstract: The additive effects of prostaglandin (PG)-EP2 agonists on a PG-FP agonist toward adipogenesis in two- or three-dimension (2D or 3D) cultures of 3T3-L1 cells was examined by lipid staining, the mRNA expression of adipogenesis related genes, and extracellular matrixes (ECMs) including collagen molecules (Col) -1, -4 and -6, and fibronectin (Fn), and the sizes and physical properties of 3D sphenoids, as measured by a micro-squeezer. The results indicate that adipogenesis induced 1) an enlargement in the sizes of 3D sphenoids, 2) a substantial enhancement in lipid staining, the expression of the PParγ, Ap2 and Leptin genes, and 3) a significant decrease in the stiffness of the 3D sphenoids. These effects were inhibited by bimatoprost acid (BIM-A), but 4) adipogenesis induced significant down-regulation of Col1 and Fn, and the significant up-regulation of the Col4 and Col6 genes were unchanged by BIM-A. On the addition of an EP2 agonist, such as omidenepag (OMD) or butaprost (Buta), to BIM-A, 1) the sizes of the 3D sphenoids were further decreased, 2) lipid staining was decreased (2D; OMD, 3D; Buta) 3) the stiffness of the 3D sphenoids was increased by Buta, 4) the expression of PParγ was up-regulated (2D; Buta) or unchanged (3D), the expression of Ap2 was down-regulated (2D; OMD) or up-regulated (3D; Buta), and the expression of Leptin was increased (2D), 5) the expression of all four (OMD) or all except Col4 (buta) in 2D, and Col1and Col4 (OMD) in 3D were up-regulated. These collective findings indicate that the addition of an EP2 agonist, OMD or Buta significantly modulated the BIM-A induced suppression of adipogenesis as well as physical properties of 2D and 3D cultured 3T3-L1 cells in different manners.
TL;DR: In this article, a nested case-control study was conducted to examine the associations of umbilical cord fatty acid profiles, D6D index, and D5D index in appropriate for gestational age.
Abstract: Long-chain polyunsaturated fatty acids (LCPUFAs) required for infant development are produced by Δ6 desaturase (D6D) and Δ5 desaturase (D5D). The D6D index and D5D index are calculated based on their respective precursor/product ratios. The D5D and D6D indices are related to obesity and lifestyle-related diseases. The aim of the present study was to examine the associations of umbilical cord fatty acid profiles, D6D index, and D5D index in appropriate for gestational age (AGA), small for gestational age (SGA), and large for gestational age (LGA) infants. This was a nested case-control study, and the relationship between case and control maternal blood and umbilical cord blood fatty acid compositions was examined. Cases were small for gestational age (SGA; n = 55) and large for gestational age (LGA; n = 149) infants, whereas controls were appropriate for gestational age (AGA; n = 204) infants. Fatty acid profiles in maternal blood and umbilical cord plasma were analyzed by gas-liquid chromatography. The D6D index was calculated as dihomo-γ-linolenic acid (DGLA 20: 3 n-6) / linoleic acid (18: 2 n - 6), and the D5D index was calculated as arachidonic acid (20: 4 n - 6) / DGLA (20: 3 n - 6). Statistical analysis of umbilical cord blood fatty acids was performed with multiple comparisons. SGA infants showed high umbilical cord values for α-linolenic acid and DHA and lower values for DGLA compared to AGA infants. SGA infants showed a higher D5D index but a lower D6D index than AGA infants. LGA infants showed high values for α-linolenic acid and DGLA and lower values for arachidonic acid than AGA infants. LGA infants showed a high D6D index and a low D5D index relative to AGA infants. No significant differences in maternal blood fatty acid profiles, the D6D index, and D5D index desaturase activities were found among the three groups. There were differences in umbilical cord fatty acid profiles and D6D and D5D indices among AGA, SGA, and LGA infants, but further study is needed.
TL;DR: In this paper, the effects of a diet with sufficient n-3 EFA content in an acceptable n-6/n-3 PUFA ratio for rodents ((n- 3)eFAS group) with those on the same diet supplemented with EPA and DHA (EPA/DHA group) in Mycobacterium tuberculosis (Mtb)-infected C3HeB/FeJ mice with a low n- 3 PUFA status.
Abstract: Intakes of the omega-3 essential fatty acids (n-3 EFAs) are low in the general adult population, with high n-6/n-3 polyunsaturated fatty acid (PUFA) ratios and the accompanying suboptimal n-3 PUFA status. Eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) have antibacterial and inflammation-resolving effects in tuberculosis (TB). However, whether switching to a diet with optimum n-3 EFA intake after the infection has comparable benefits has not been investigated. We aimed to compare the effects of a diet with sufficient n-3 EFA content in an acceptable n-6/n-3 PUFA ratio for rodents ((n-3)eFAS group) with those on the same diet supplemented with EPA and DHA (EPA/DHA group) in Mycobacterium tuberculosis (Mtb)-infected C3HeB/FeJ mice with a low n-3 PUFA status. Mice were conditioned on an n-3 PUFA-deficient diet with a high n-6/n-3 PUFA ratio for 6 weeks before Mtb infection and randomized to either (n-3)eFAS or EPA/DHA diets 1 week post-infection for 3 weeks. At endpoint, EPA and DHA compositions were higher and arachidonic acid, osbond acid, and total n-6 LCPUFAs lower in all lipid pools measured in the EPA/DHA group (all P
TL;DR: In this article, the authors assessed the mRNA and protein expression of fatty acid-binding proteins (FABPs) and fatty acid transport proteins(FATPs) in mouse BV-2 cells and their mRNA expression in primary mouse microglia.
Abstract: While the processes governing docosahexaenoic acid (DHA) trafficking across the blood-brain barrier have been elucidated, factors governing DHA uptake into microglia, an essential step for this fatty acid to exert its anti-inflammatory effects, are unknown. This study assessed the mRNA and protein expression of fatty acid-binding proteins (FABPs) and fatty acid transport proteins (FATPs) in mouse BV-2 cells and their mRNA expression in primary mouse microglia. The microglial uptake of DHA-d5, a surrogate of DHA, was assessed by LC-MS/MS following interventions including temperature reduction, silencing of various FABP isoforms, competition with DHA, and metabolic inhibition. It was found that DHA-d5 uptake at 4°C was 39.6% lower than at 37°C, suggesting that microglial uptake of DHA-d5 likely involves passive and/or active uptake mechanisms. Of all FABP and FATP isoforms probed, only FABP3, FABP4, FABP5, FATP1, and FATP4 were expressed at both the mRNA and protein level. Silencing of FABP3, FABP4, and FABP5 resulted in no change in cellular DHA-d5 uptake, nor did concomitant DHA administration or the presence of 0.1% sodium azide/50 mM 2-deoxy-D-glucose. This study is the first to identify the presence of FABPs and FATPs in mouse microglia, albeit these proteins are not involved in the microglial uptake of DHA-d5.
TL;DR: The findings suggest that PAME can provide neuroprotection in the presence of ACA to alleviate neuroinflammation and ameliorate mitochondrial dysfunction.
Abstract: We previously discovered that palmitic acid methyl ester (PAME) is a potent vasodilator released from the sympathetic ganglion with vasoactive properties. Post-treatment with PAME can enhance cortical cerebral blood flow and functional learning and memory, while inhibiting neuronal cell death in the CA1 region of the hippocampus under pathological conditions (i.e. cerebral ischemia). Since mechanisms underlying PAME-mediated neuroprotection remain unclear, we investigated the possible neuroprotective mechanisms of PAME after 6 min of asphyxial cardiac arrest (ACA, an animal model of global cerebral ischemia). Our results from capillary-based immunoassay (for the detection of proteins) and cytokine array suggest that PAME (0.02 mg/kg) can decrease neuroinflammatory markers, such as ionized calcium binding adaptor molecule 1 (Iba1, a specific marker for microglia/macrophage activation) and inflammatory cytokines after cardiopulmonary resuscitation. Additionally, the mitochondrial oxygen consumption rate (OCR) and respiratory function in the hippocampal slices were restored following ACA (via Seahorse XF24 Extracellular Flux Analyzer) suggesting that PAME can ameliorate mitochondrial dysfunction. Finally, hippocampal protein arginine methyltransferase 1 (PRMT1) and PRMT8 are enhanced in the presence of PAME to suggest a possible pathway of methylated fatty acids to modulate arginine-based enzymatic methylation. Altogether, our findings suggest that PAME can provide neuroprotection in the presence of ACA to alleviate neuroinflammation and ameliorate mitochondrial dysfunction.
TL;DR: In this paper, the effect of Omega (n)-3 polyunsaturated fatty acids (PUFAs) can effectively treat depression via anti-inflammatory and neuroprotective effects.
Abstract: Objectives Olfactory bulbectomy (OB) induced behaviors, hypercortisolism, inflammation and neurotrophin dysfunctions are similar to those observed in depressed patients. Omega (n)-3 polyunsaturated fatty acids (PUFAs) can effectively treat depression via anti-inflammatory and neuroprotective effects. However, n-3 PUFA purities, caloric contents, and ratios in different diets often cause contradictive results. This study used Fat-1 mice, which can convert n-6 to n-3 PUFAs in the brain, to study the effect of n-3 PUFAs on OB-induced behaviors and related changes. Methods Fat-1 and wild-type littermates were fed safflower oil for 3 months. Behaviors were tested on day 21 after surgery. Monoamine neurotransmitters were measured by HPLC. Macrophage activity was measured by MTT assay. Astrocyte phenotypes A1 S100β, A2 BDNF and cholesterol level were measured by ELISA and total cholesterol assay kits respectively. PUFA profile and membrane fluidity were detected by GC and DPH fluorescence probe respectively. Results OB significantly induced animal hyperactivity and spatial memory impairment, while decreased sucrose consumption and social contact with decreased 5-HT turnover, increased the macrophage activity and S100β/BDNF ratio. Meanwhile, n-3/n-6 PUFAs ratio and total cholesterol level were reduced in OB mice. Whereas, OB-induced behavioral changes were attenuated, which were associated with increasing 5-HT turnover, decrease macrophage activity, restored S100β/BDNF and n-3/n-6 PUFAs ratios, and total cholesterol concentrations in Fat-1 mice. Conclusion The present study for the first time demonstrated that endogenous n-3 PUFAs attenuated OB-induced depression-like behaviors and spatial memory impairment through modulating serotonergic and immune function, balancing the astrocyte A1/A2 phenotypes, and normalizing PUFAs profile and membrane function.
TL;DR: In this paper, the effects of AEA on the endocannabinoid system (ECS) were investigated on granulosa cells line COV434 and showed that AEA induced an increase in caspase -3/-7 activity in both cell models.
Abstract: The endocannabinoid system (ECS) plays a crucial role in human reproduction. Changes in anandamide (AEA) levels affect reproductive events and has already been suggested as biomarker of reproductive potential of male and female gametes. Although cannabinoid-receptor 1 (CB1) was already identified in human granulosa cells (hGCs) the ECS was not characterized on granulosa cells line COV434 nor the effects of AEA on GCs viability and function depicted. Therefore, the aim of this study was to characterize the ECS elements and explore the effects of AEA on both COV434 and hGCs. Our results revealed that hGCs express the full enzymatic machinery responsible for AEA metabolism as well as cannabinoid receptors. In addition, AEA induced a reduction in both COV434 and hGCs viability in a concentration and time-dependent manner. Nevertheless, the effects of AEA in cell viability was independent of either CB1 or CB2 receptors. There was no ROS release in both cell models; however, AEA induced morphological changes, presenting chromatin condensation at 72 h, and variation on mitochondrial membrane potential. Moreover, AEA induced an increase in caspase -3/-7 activities in both cell models, but in hGCs there was also an increase in caspase 8 activity. This study supports the idea that ECS balance is crucial for folliculogenesis and oocyte quality as dysregulated AEA levels may compromise female fertility.
TL;DR: In this article, the dietary omega-3 PUFA [alpha-Linolenic acid (ALA), DHA, and EPA] intake and plasma fatty acid levels among school-going children were delineated.
Abstract: Long-chain omega-3 polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) play an essential role in cognitive and behavioural changes among school going children. This study delineates the dietary omega-3 PUFA [alpha-Linolenic acid (ALA), DHA, and EPA] intake and plasma fatty acids levels among school-going children. This is a cross-sectional study purely observational in nature, wherein 625 apparently healthy boys and girls aged between 7 and 13 years were selected from five different schools of Hyderabad. Dietary information on omega-3 PUFA (ALA, DHA, and EPA) intake was collected using a food frequency questionnaire. Plasma fatty acid concentrations were measured in 34% of sub-sample using standard gas chromatography. The study revealed that the average dietary intakes of omega-3 PUFA, ALA, DHA, and EPA were 55.46, 15.82, 35.59, 4.06 mg/day, respectively. There was a significant difference in mean DHA intake among gender and age group [girls (38.64±1.45 mg/day), boys (31.80±1.38 mg/day) p
TL;DR: Findings are extended to another n-3 PUFA-rich oil (stearidonic acid [SDA]-enriched soybean oil) and two other high-OA oils, suggesting that the effect is not plant oil-specific.
Abstract: Summary We previously reported that when laying hens were fed diets supplemented with oils enriched in α-linolenic acid (ALA) and oleic acid (OA), the deposition of n-3 PUFA in egg yolk was attenuated as compared to feeding hens a diet supplemented with the ALA-rich oil alone. The present work extends those findings to another n-3 PUFA-rich oil (stearidonic acid [SDA]-enriched soybean oil) and two other high-OA oils, suggesting that the effect is not plant oil-specific. Feeding hens a supplemental linoleic acid (LA)-rich oil plus an oil rich in either SDA or ALA also attenuated egg yolk ALA and SDA contents (Experiment 1), or egg yolk and liver ALA contents (Experiment 2), respectively, as compared to feeding the SDA- or ALA-rich oils alone. Future work should focus on the lack of neutrality of OA and LA in relation to n-3 PUFA nutrition.
TL;DR: In this paper, the presence of hypercholesterolemia (HC) in the follow-up changes the levels of specialized proresoving lipid mediators (SPMs) called Lipoxin (Lxs) and Resolvin (Rvs).
Abstract: Vascular structure and integrity are at the forefront of blood pressure regulation. However, there are many factors that affect the responses of the vessels. One of these is the inflammatory processes associated with high cholesterol and its modification. 15-lipoxygenase (15-LOX) is the critical enzyme in cholesterol oxidation, but this enzyme is also responsible for the synthesis of specialized proresoving lipid mediators (SPMs) called Lipoxin (Lxs) and Resolvin (Rvs). In this study, we determined serum LXA4, RvD1 and RvE1 levels in newly diagnosed hypertension (HT) and normotension (NT) cases. We evaluated how the presence of hypercholesterolemia (HC) in the follow-up changes the levels of these SPMs. We found that the three SPMs we measured decreased significantly in the presence of HC. In addition, we found a negative and significant correlation with systolic blood pressure and total cholesterol levels for the three SPMs. In conclusion, HT and HC are independent risk factors for cardiovascular death. However, the presence of HC may be an important factor for the development of HT. Increasing cholesterol levels may cause 15-LOX to shift towards LDL oxidation, thus leading to inflammation. This situation may negatively affect the vascular functions in the regulation of blood pressure. Serum LXA4, RvD1 and RvE1 measurements may provide clues that represent a shift of 15-LOX enzyme activity towards cholesterol.
TL;DR: Antiemetic doses of dexamethasone given during surgery increased plasma LTB4 and 20-HETE at a time when hs-CRP was significantly reduced and plasma SPM pathway intermediates and RvE3 were unaffected.
Abstract: Introduction Dexamethasone is an antiemetic that is frequently administered before or after the induction of anesthesia for prevention and treatment of perioperative nausea and vomiting. Dexamethasone has anti-inflammatory and immunosuppressive effects primarily via suppression of expression of inflammatory mediators. However, its effect on the eicosanoids and docosanoids that mediate the inflammatory response and inflammation resolution are unclear. We aimed to assess the effect of a single dose of intra-operative dexamethasone on peri‑operative eicosanoids involved in inflammation including leukotriene B4 (LTB4) and 20-hydroxyeicosatetraenoic acid (20-HETE), and inflammation resolution (Specialised Proresolving Mediators (SPM)). Patients and Methods A subgroup of 80 patients from the randomised controlled PADDAG trial was enrolled into this substudy. They were allocated to receive 0, 4 or 8 mg dexamethasone administered intravenously at induction of anesthesia. Blood samples were collected before and 24 h after dexamethasone, for measurement of leukocytes, hs-CRP, LTB4, 20-HETE, the SPM pathway intermediates (14-HDHA, 18-HEPE and 17-HDHA) and SPMs (E-series resolvins, and d -series resolvins). Results Compared to the administration of placebo, neutrophil count was elevated (P Conclusion Antiemetic doses of dexamethasone given during surgery increased plasma LTB4 and 20-HETE at a time when hs-CRP was significantly reduced. Plasma SPM pathway intermediates and RvE3 were unaffected.