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Prostaglandins & Other Lipid Mediators Jun 2023Specialized pro-resolving lipid mediators (SPMs) such as lipoxins or resolvins are formed by the consecutive action of 5-lipoxygenase (5-LO, ALOX5) and different types... (Review)
Review
Specialized pro-resolving lipid mediators (SPMs) such as lipoxins or resolvins are formed by the consecutive action of 5-lipoxygenase (5-LO, ALOX5) and different types of arachidonic acid 12- or 15-lipoxygenases using arachidonic acid, eicosapentaenoic acid or docosahexaenoic acid as substrate. Lipoxins are trihydroxylated oxylipins which are formed from arachidonic and eicosapentaenoic acid. The latter can also be converted to di- and trihydroxylated resolvins of the E series, whereas docosahexaenoic acid is the substrate for the formation of di- and trihydroxylated resolvins of the D series. Here, we summarize the formation of lipoxins and resolvins in leukocytes. From the data published so far, it becomes evident that FLAP is required for the biosynthesis of most of the lipoxins and resolvins. Even in the presence of FLAP, formation of the trihydroxylated SPMs (lipoxins, RvD1-RvD4, RvE1) in leukocytes is very low or undetectable which is obviously due to the extremely low epoxide formation by 5-LO from oxylipins such as 15-H(p)ETE, 18-H(p)EPE or 17-H(p)DHA. As a result, only the dihydroxylated oxylipins (5 S,15S-diHETE, 5 S,15S-diHEPE) and resolvins (RvD5, RvE2, RvE4) can be consistently detected using leukocytes as SPM source. However, the reported levels of these dihydroxylated lipid mediators are still much lower than those of the typical pro-inflammatory mediators including the monohydroxylated fatty acid derivatives (e.g. 5-HETE), leukotrienes or cyclooxygenase-derived prostaglandins. Since 5-LO expression is mainly restricted to leukocytes these cells are considered as the main source of SPMs. The low formation of trihydroxylated SPMs in leukocytes, the fact that they are hardly detected in biological samples as well as the lack of functional signaling by their receptors make it highly questionable that trihydroxylated SPMs play a role as endogenous mediators in the resolution of inflammation.
Topics: Humans; Lipoxins; Docosahexaenoic Acids; Eicosapentaenoic Acid; Arachidonic Acid; Oxylipins; Eicosanoids; Inflammation; Leukocytes
PubMed: 36878381
DOI: 10.1016/j.prostaglandins.2023.106726 -
International Journal of Molecular... Apr 2022The neurodevelopmental and neuroprotective actions of docosahexaenoic acid (DHA) are mediated by mechanisms involving membrane- and metabolite-related signal... (Review)
Review
The neurodevelopmental and neuroprotective actions of docosahexaenoic acid (DHA) are mediated by mechanisms involving membrane- and metabolite-related signal transduction. A key characteristic in the membrane-mediated action of DHA results from the stimulated synthesis of neuronal phosphatidylserine (PS). The resulting DHA-PS-rich membrane domains facilitate the translocation and activation of kinases such as Raf-1, protein kinase C (PKC), and Akt. The activation of these signaling pathways promotes neuronal development and survival. DHA is also metabolized in neural tissues to bioactive mediators. Neuroprotectin D1, a docosatriene synthesized by the lipoxygenase activity, has an anti-inflammatory property, and elovanoids formed from DHA elongation products exhibit antioxidant effects in the retina. Synaptamide, an endocannabinoid-like lipid mediator synthesized from DHA in the brain, promotes neurogenesis and synaptogenesis and exerts anti-inflammatory effects. It binds to the GAIN domain of the GPR110 (ADGRF1) receptor, triggers the cAMP/protein kinase A (PKA) signaling pathway, and activates the cAMP-response element binding protein (CREB). The DHA status in the brain influences not only the PS-dependent signal transduction but also the metabolite formation and expression of pre- and post-synaptic proteins that are downstream of the CREB and affect neurotransmission. The combined actions of these processes contribute to the neurodevelopmental and neuroprotective effects of DHA.
Topics: Anti-Inflammatory Agents; Cyclic AMP Response Element-Binding Protein; Docosahexaenoic Acids; Endocannabinoids; Neuroprotection; Signal Transduction
PubMed: 35563025
DOI: 10.3390/ijms23094635 -
Progress in Lipid Research Jul 2023This review is about the role of arachidonic acid (ArA) in foetal and early growth and development. In 1975 and '76, we reported the preferential incorporation of ArA... (Review)
Review
This review is about the role of arachidonic acid (ArA) in foetal and early growth and development. In 1975 and '76, we reported the preferential incorporation of ArA into the developing brain of rat pups, its conservation as a principal component in the brains of 32 mammalian species and the high proportion delivered by the human placenta for foetal nutrition, compared to its parent linoleic acid (LA). ArA is quantitatively the principal acyl component of membrane lipids from foetal red cells, mononuclear cells, astrocytes, endothelium, and placenta. Functionally, we present evidence that ArA, but not DHA, relaxes the foetal mesenteric arteries. The placenta biomagnifies ArA, doubling the proportion of the maternal level in cord blood. The proportions of ArA and its allies (di-homo-gamma-linolenic acid (DGLA), adrenic acid and ω6 docosapentaenoic acid) are similar or higher than the total of ω3 fatty acids in human milk, maintaining the abundant supply to the developing infant. Despite the evidence of the importance of ArA, the European Food Standard Agency, in 2014 rejected the joint FAO and WHO recommendation on the inclusion of ArA in infant formula, although they recommended DHA. The almost universal dominance of ArA in the membrane phosphoglycerides during human organogenesis and prenatal growth suggests that the importance of ArA and its allies in reproductive biology needs to be re-evaluated urgently.
Topics: Pregnancy; Female; Humans; Animals; Rats; Arachidonic Acid; Docosahexaenoic Acids; Linoleic Acid; Infant Formula; Glycerophospholipids; Mammals
PubMed: 36746351
DOI: 10.1016/j.plipres.2023.101222 -
Nutrients Dec 2020Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 polyunsaturated fatty acids (PUFAs) consumed in low abundance in the Western diet. Increased... (Review)
Review
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 polyunsaturated fatty acids (PUFAs) consumed in low abundance in the Western diet. Increased consumption of n-3 PUFAs may have beneficial effects for a wide range of physiological outcomes including chronic inflammation. However, considerable mechanistic gaps in knowledge exist about EPA versus DHA, which are often studied as a mixture. We suggest the novel hypothesis that EPA and DHA may compete against each other through overlapping mechanisms. First, EPA and DHA may compete for residency in membrane phospholipids and thereby differentially displace n-6 PUFAs, which are highly prevalent in the Western diet. This would influence biosynthesis of downstream metabolites of inflammation initiation and resolution. Second, EPA and DHA exert different effects on plasma membrane biophysical structure, creating an additional layer of competition between the fatty acids in controlling signaling. Third, DHA regulates membrane EPA levels by lowering its rate of conversion to EPA's elongation product n-3 docosapentaenoic acid. Collectively, we propose the critical need to investigate molecular competition between EPA and DHA in health and disease, which would ultimately impact dietary recommendations and precision nutrition trials.
Topics: Animals; Arachidonic Acid; Diet; Diet, Western; Dietary Supplements; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Humans; Inflammation; Phospholipids
PubMed: 33276463
DOI: 10.3390/nu12123718 -
Nutrients Oct 2022Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-omega-3 fatty acids with various functions-influence sleep in children and young adults. However, only limited... (Randomized Controlled Trial)
Randomized Controlled Trial
Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-omega-3 fatty acids with various functions-influence sleep in children and young adults. However, only limited studies on their effects on sleep in middle- and old-aged adults have been reported. Therefore, we investigated the effects of DHA and EPA on sleep quality in subjects aged ≥ 45 years. We performed a randomized, placebo-controlled, double-blinded, parallel-grouped study, in which we randomly assigned 66 healthy Japanese males and females. Each individual received six 480 mg capsules containing 576 mg DHA and 284 mg EPA per day (DHA/EPA group, = 33), or corn oil (placebo group, = 33), for 12 weeks. Before and after the intervention, the Oguri-Shirakawa-Azumi sleep inventory MA version (OSA-MA) and the sleep state test were conducted. In the DHA/EPA group, factor III (frequent dreaming) scores among the OSA-MA scores were significantly improved compared to the placebo group. Additionally, sleep state tests revealed that sleep efficiency improved in the DHA/EPA group. To our knowledge, this study is the first to report that DHA/EPA improves sleep quality in middle- and old-aged individuals, even at doses lower than those administered in previous studies.
Topics: Aged; Capsules; Corn Oil; Dietary Supplements; Docosahexaenoic Acids; Double-Blind Method; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Female; Healthy Volunteers; Humans; Male; Middle Aged; Sleep Apnea, Obstructive; Sleep Quality; Thromboplastin
PubMed: 36235788
DOI: 10.3390/nu14194136 -
Journal of Lipid Research Jun 2024DHA is abundant in the brain where it regulates cell survival, neurogenesis, and neuroinflammation. DHA can be obtained from the diet or synthesized from alpha-linolenic...
DHA is abundant in the brain where it regulates cell survival, neurogenesis, and neuroinflammation. DHA can be obtained from the diet or synthesized from alpha-linolenic acid (ALA; 18:3n-3) via a series of desaturation and elongation reactions occurring in the liver. Tracer studies suggest that dietary DHA can downregulate its own synthesis, but the mechanism remains undetermined and is the primary objective of this manuscript. First, we show by tracing C content (δC) of DHA via compound-specific isotope analysis, that following low dietary DHA, the brain receives DHA synthesized from ALA. We then show that dietary DHA increases mouse liver and serum EPA, which is dependant on ALA. Furthermore, by compound-specific isotope analysis we demonstrate that the source of increased EPA is slowed EPA metabolism, not increased DHA retroconversion as previously assumed. DHA feeding alone or with ALA lowered liver elongation of very long chain (ELOVL2, EPA elongation) enzyme activity despite no change in protein content. To further evaluate the role of ELOVL2, a liver-specific Elovl2 KO was generated showing that DHA feeding in the presence or absence of a functional liver ELOVL2 yields similar results. An enzyme competition assay for EPA elongation suggests both uncompetitive and noncompetitive inhibition by DHA depending on DHA levels. To translate our findings, we show that DHA supplementation in men and women increases EPA levels in a manner dependent on a SNP (rs953413) in the ELOVL2 gene. In conclusion, we identify a novel feedback inhibition pathway where dietary DHA downregulates its liver synthesis by inhibiting EPA elongation.
Topics: Docosahexaenoic Acids; Animals; Eicosapentaenoic Acid; Liver; Mice; Down-Regulation; Male; Mice, Inbred C57BL; alpha-Linolenic Acid
PubMed: 38649096
DOI: 10.1016/j.jlr.2024.100548 -
Nutrients Nov 2022Hypoxia is caused by the excessive expansion of the white adipose tissue (AT) and is associated with obesity-related conditions such as insulin resistance, inflammation,...
BACKGROUND
Hypoxia is caused by the excessive expansion of the white adipose tissue (AT) and is associated with obesity-related conditions such as insulin resistance, inflammation, and oxidative stress. Docosahexaenoic acid (DHA) is an omega-3 fatty acid reported to have beneficial health effects. However, the effects of DHA in AT against hypoxia-induced immune-metabolic perturbations in adipocytes exposed to low O tension are not well known. Consequently, this study aimed to evaluate the impact of DHA on markers of inflammation, metabolism, apoptosis, and oxidative stress in 3T3-L1 cell adipocytes exposed to low O tension (1% O) induced hypoxia.
METHODS
The apoptosis and reactive oxygen species (ROS) rates were evaluated. Metabolic parameters such as lactate, FFA, glycerol release, glucose uptake, and ATP content were assessed by a fluorometer. The expression of HIF-1, GLUT1 and the secretion of adipocytokines such as leptin, adiponectin, and pro-inflammatory markers was evaluated.
RESULTS
DHA-treated hypoxic cells showed significantly decreased basal free fatty acid release, lactate production, and enhanced glucose consumption. In addition, DHA-treatment of hypoxic cells caused a significant reduction in the apoptosis rate and ROS production with decreased lipid peroxidation. Moreover, DHA-treatment of hypoxic cells caused a decreased secretion of pro-inflammatory markers (IL-6, MCP-1) and leptin and increased adiponectin secretion compared with hypoxic cells. Furthermore, DHA-treatment of hypoxic cells caused significant reductions in the expression of genes related to hypoxia (HIF-1, HIF-2), anaerobic metabolism (GLUT1 and Ldha), ATP production (ANT2), and fat metabolism (FASN and PPARY).
CONCLUSION
This study suggests that DHA can exert potential anti-obesity effects by reducing the secretion of inflammatory adipokines, oxidative stress, lipolysis, and apoptosis.
Topics: Mice; Animals; 3T3-L1 Cells; Docosahexaenoic Acids; Leptin; Glucose Transporter Type 1; Adiponectin; Reactive Oxygen Species; Adipocytes; Inflammation; Hypoxia; Obesity; Adipokines; Biomarkers; Lactates; Adenosine Triphosphate
PubMed: 36364860
DOI: 10.3390/nu14214600 -
Seminars in Immunology Jan 2022Specialized pro-resolving mediators (SPMs) are endogenous small molecules produced mainly from dietary omega-3 polyunsaturated fatty acids by both structural cells and... (Review)
Review
Specialized pro-resolving mediators (SPMs) are endogenous small molecules produced mainly from dietary omega-3 polyunsaturated fatty acids by both structural cells and cells of the active and innate immune systems. Specialized pro-resolving mediators have been shown to both limit acute inflammation and promote resolution and return to homeostasis following infection or injury. There is growing evidence that chronic immune disorders are characterized by deficiencies in resolution and SPMs have significant potential as novel therapeutics to prevent and treat chronic inflammation and immune system disorders. This review focuses on important breakthroughs in understanding how SPMs are produced by, and act on, cells of the adaptive immune system, specifically macrophages, B cells and T cells. We also highlight recent evidence demonstrating the potential of SPMs as novel therapeutic agents in topics including immunization, autoimmune disease and transplantation.
Topics: Humans; Docosahexaenoic Acids; Fatty Acids, Omega-3; Inflammation; Inflammation Mediators; Immunity
PubMed: 35660338
DOI: 10.1016/j.smim.2022.101605 -
Canadian Family Physician Medecin de... Jul 2023To explore the evidence for omega-3 fatty acid (O3FA) supplementation in primary and secondary prevention of cardiovascular disease (CVD).
OBJECTIVE
To explore the evidence for omega-3 fatty acid (O3FA) supplementation in primary and secondary prevention of cardiovascular disease (CVD).
SOURCES OF INFORMATION
PubMed, Cochrane reviews, and Google Scholar were searched for meta-analyses and reviews related to O3FAs and CVD. Salient, recent randomized controlled trials referenced in these reviews were retrieved. Current lipid guidelines were reviewed.
MAIN MESSAGE
Most O3FAs are derived from marine or aquatic microalgae, which are consumed by fish. The essential fatty acids eicosapentaenoic acid and docosahexaenoic acid are mainly sourced from fish, with a small fraction coming from plants. Omega-3 fatty acids modestly lower triglyceride levels, but the major impact on CVD is through a variety of other mechanisms related to cell membrane function, antioxidant properties, and reduction of atherogenic small low-density lipoprotein cholesterol particles. Guidelines continue to recommend eating 2 servings of fish per week. There is little evidence of benefit of O3FAs in primary prevention of CVD. Given that 40% of Canadians have insufficient levels and that these low levels may be associated with other chronic diseases over time, supplementation with O3FAs could be considered, particularly in those with hypertriglyceridemia, in those who eat no fish, or for vegetarians or vegans. Doses up to 1 g daily are considered safe. For secondary prevention after statin optimization, if triglyceride levels are between 1.5 and 5.6 mmol/L, guidelines recommend with level 1A evidence taking 2 g of icosapent ethyl twice a day. This is also recommended in primary prevention for patients with diabetes and hypertriglyceridemia and additional CVD risk factors. As fish stocks dwindle over time, preserving fisheries for developing countries and obtaining O3FA from microalgal or genetically modified plant sources may become important.
CONCLUSION
All guidelines recommend at least 2 servings of oily fish per week, although benefit from O3FAs is mostly seen in secondary prevention. Fish oil and combination preparations of eicosapentaenoic acid and docosahexaenoic acid have failed to show benefit at any dose at any level of prevention in patients who are appropriately prescribed statins. High-dose eicosapentaenoic acid shows substantial benefit in selected patients taking statins who have high triglyceride levels.
Topics: Humans; Fatty Acids, Omega-3; Cardiovascular Diseases; Eicosapentaenoic Acid; Docosahexaenoic Acids; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Canada; Hypertriglyceridemia; Triglycerides; Dietary Supplements; Pharmaceutical Preparations
PubMed: 37452000
DOI: 10.46747/cfp.6907459 -
The Journal of Maternal-fetal &... Dec 2023: Macrosomia is a common disorder that occurs during pregnancy. We investigated the comprehensive metabolite profiles of pregnant maternal and fetal sera in...
: Macrosomia is a common disorder that occurs during pregnancy. We investigated the comprehensive metabolite profiles of pregnant maternal and fetal sera in normoglycemic macrosomia in a Chinese population. Forty pregnant women and their fetuses were included in the study (twenty macrosomia patients and twenty normal-weight controls). Maternal and umbilical cord serum metabolites were identified using ultra-performance liquid chromatography coupled with tandem mass spectrometry. In total, 203 metabolites were identified. Lipids and lipid-like molecules were the predominant metabolites. Fifty-three metabolites with significant differences were obtained in the maternal samples. In the macrosomia group, the levels of docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid were significantly higher than those in the control group. Umbilical cord serum samples were obtained for 24 different metabolites. The maternal-fetal gradient of polyunsaturated fatty acids was decreased in the macrosomia group. Aconitic acid, citric acid, isocitric acid, 2-methylhexanoic acid, and 12-hydroxystearic acid were the common differential metabolites in the maternal and umbilical cord serum samples. There were obvious metabolic abnormalities in the sera of pregnant women and fetuses with macrosomia. Lipids and lipid-like molecules were the predominant differential metabolites but had different classifications in the maternal and umbilical cord serum. These results may provide new insights into the long-term metabolic disorders associated with macrosomia.
Topics: Humans; Pregnancy; Female; Fetal Macrosomia; Fetal Blood; Metabolomics; Docosahexaenoic Acids; Chromatography, Liquid
PubMed: 37848386
DOI: 10.1080/14767058.2023.2270761