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Nutrients Jul 2017The associations between -3 polyunsaturated fatty acids (PUFAs) and metabolic syndrome (MetS) risk have demonstrated inconsistent results. The present study aimed to... (Meta-Analysis)
Meta-Analysis Review
The associations between -3 polyunsaturated fatty acids (PUFAs) and metabolic syndrome (MetS) risk have demonstrated inconsistent results. The present study aimed to investigate whether higher circulating -3 PUFAs and dietary -3 PUFAs intake have a protective effect on MetS risk. A systematic literature search in the PubMed, Scopus, and Chinese National Knowledge Infrastructure (CNKI) databases was conducted up to March 2017. Odd ratios (ORs) from case-control and cross-sectional studies were combined using a random-effects model for the highest versus lowest category. The differences of -3 PUFAs between healthy subjects and patients with MetS were calculated as weighted mean difference (WMD) by using a random-effects model. Seven case-control and 20 cross-sectional studies were included. A higher plasma/serum -3 PUFAs was associated with a lower MetS risk (Pooled OR = 0.63, 95% CI: 0.49, 0.81). The plasma/serum -3 PUFAs in controls was significantly higher than cases (WMD: 0.24; 95% CI: 0.04, 0.43), especially docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). However, no significant association was found between dietary intake of -3 PUFAs or fish and MetS risk. The present study provides substantial evidence of a higher circulating -3 PUFAs associated with a lower MetS risk. The circulating -3 PUFAs can be regarded as biomarkers indicating MetS risk, especially DPA and DHA.
Topics: Fatty Acids, Omega-3; Humans; Metabolic Syndrome; Odds Ratio; Risk Factors
PubMed: 28684692
DOI: 10.3390/nu9070703 -
Frontiers in Physiology 2021Arachidonic acid (ARA) is an important ω-6 polyunsaturated fatty acid (PUFA), and docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and n-3 docosapentaenoic acid... (Review)
Review
Arachidonic acid (ARA) is an important ω-6 polyunsaturated fatty acid (PUFA), and docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and n-3 docosapentaenoic acid (n-3 DPA) are three well-known ω-3 PUFAs. These fatty acids can be metabolized into a number of bioactive lipids. Eicosanoids derived from ARA have drawn great attention because of their important and complex biofunctions. Although EPA, DHA and n-3 DPA have also shown powerful biofunctions, we have fewer studies of metabolites derived from them than those from ARA. Recently, growing research has focused on the bioaction of ω-3 PUFA-derived metabolites, which indicates their great potential for treating metabolic disorders. Most of the functional studies of these bioactive lipids focused on their anti-inflammatory effects. However, several studies elucidated their direct effects on pancreatic β cells, hepatocytes, adipocytes, skeletal muscle cells, and endothelial cells. These researches revealed the importance of studying the functions of metabolites derived from ω-3 polyunsaturated fatty acids other than themselves. The current review summarizes research into the effects of ω-3 PUFA-derived oxylipins on metabolic disorders, including diabetes, non-alcoholic fatty liver disease, adipose tissue dysfunction, and atherosclerosis.
PubMed: 34113260
DOI: 10.3389/fphys.2021.646491 -
Foods (Basel, Switzerland) Jan 2021Epithelial cells (enterocytes) form part of the intestinal barrier, the largest human interface between the internal and external environments, and responsible for... (Review)
Review
Epithelial cells (enterocytes) form part of the intestinal barrier, the largest human interface between the internal and external environments, and responsible for maintaining regulated intestinal absorption and immunological control. Under inflammatory conditions, the intestinal barrier and its component enterocytes become inflamed, leading to changes in barrier histology, permeability, and chemical mediator production. Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) can influence the inflammatory state of a range of cell types, including endothelial cells, monocytes, and macrophages. This review aims to assess the current literature detailing the effects of ω-3 PUFAs on epithelial cells. Marine-derived ω-3 PUFAs, eicosapentaenoic acid and docosahexaenoic acid, as well as plant-derived alpha-linolenic acid, are incorporated into intestinal epithelial cell membranes, prevent changes to epithelial permeability, inhibit the production of pro-inflammatory cytokines and eicosanoids and induce the production of anti-inflammatory eicosanoids and docosanoids. Altered inflammatory markers have been attributed to changes in activity and/or expression of proteins involved in inflammatory signalling including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), peroxisome proliferator activated receptor (PPAR) α and γ, G-protein coupled receptor (GPR) 120 and cyclooxygenase (COX)-2. Effective doses for each ω-3 PUFA are difficult to determine due to inconsistencies in dose and time of exposure between different in vitro models and between in vivo and in vitro models. Further research is needed to determine the anti-inflammatory potential of less-studied ω-3 PUFAs, including docosapentaenoic acid and stearidonic acid.
PubMed: 33478161
DOI: 10.3390/foods10010199 -
Biochimica Et Biophysica Acta Dec 2010A new genus of specialized pro-resolving mediators (SPM) which include several families of distinct local mediators (lipoxins, resolvins, protectins, and maresins) are... (Review)
Review
A new genus of specialized pro-resolving mediators (SPM) which include several families of distinct local mediators (lipoxins, resolvins, protectins, and maresins) are actively involved in the clearance and regulation of inflammatory exudates to permit restoration of tissue homeostasis. Classic lipid mediators that are temporally regulated are formed from arachidonic acid, and novel local mediators were uncovered that are biosynthesized from ω-3 poly-unsaturated fatty acids, such as eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid. The biosynthetic pathways for resolvins are constituted by fatty acid lipoxygenases and cyclooxygenase-2 via transcellular interactions established by innate immune effector cells which migrate from the vasculature to inflamed tissue sites. SPM provide local control over the execution of an inflammatory response towards resolution, and include recently recognized actions of SPM such as tissue protection and host defense. The structural families of the SPM do not resemble classic eicosanoids (PG or LT) and are novel structures that function uniquely via pro-resolving cellular and molecular targets. The extravasation of inflammatory cells expressing SPM biosynthetic routes are matched by the temporal provision of essential fatty acids from circulation needed as substrate for the formation of SPM. The present review provides an update and overview of the biosynthetic pathways and actions of SPM, and examines resolution as an integrated component of the inflammatory response and its return to homeostasis via biochemically active resolution mechanisms.
Topics: Animals; Humans; Inflammation Mediators; Lipid Metabolism
PubMed: 20708099
DOI: 10.1016/j.bbalip.2010.08.002 -
Frontiers in Immunology 2023Activation of pancreatic stellate cells (PSCs) to cancer-associated fibroblasts (CAFs) is responsible for the extensive desmoplastic reaction observed in PDAC stroma: a...
Activation of pancreatic stellate cells (PSCs) to cancer-associated fibroblasts (CAFs) is responsible for the extensive desmoplastic reaction observed in PDAC stroma: a key driver of pancreatic ductal adenocarcinoma (PDAC) chemoresistance leading to poor prognosis. Specialized pro-resolving mediators (SPMs) are prime modulators of inflammation and its resolution, traditionally thought to be produced by immune cells. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based lipid mediator profiling PSCs as well as primary human CAFs express enzymes and receptors to produce and respond to SPMs. Human PSC/CAF SPM secretion profile can be modulated by rendering these cells activated [transforming growth factor beta (TGF-β)] or quiescent [all- retinoic acid (ATRA)]. ATRA-induced nuclear translocation of arachidonate-15-lipoxygenase (ALOX15) was linked to increased production of n-3 docosapentaenoic acid-derived Resolvin D5 (RvD5), among other SPMs. Inhibition of RvD5 formation increases cancer cell invasion, whereas addback of this molecule reduced activated PSC-mediated cancer cell invasion. We also observed that circulating concentrations of RvD5 levels were decreased in peripheral blood of metastatic PDAC patients when compared with those measured in plasma of non-metastatic PDAC patients. Together, these findings indicate that RvD5 may regulate cancer-stroma cross-talk and invasion.
Topics: Humans; Arachidonate 15-Lipoxygenase; Pancreatic Stellate Cells; Chromatography, Liquid; Tandem Mass Spectrometry; Pancreatic Neoplasms; Carcinoma, Pancreatic Ductal; Tretinoin; Neoplasm Invasiveness
PubMed: 38035115
DOI: 10.3389/fimmu.2023.1248547 -
Current Opinion in Lipidology Feb 2016The review presents recent developments in the identification of specialized proresolving mediators (SPMs) of inflammation following supplementation with n-3 fatty acids... (Review)
Review
PURPOSE OF REVIEW
The review presents recent developments in the identification of specialized proresolving mediators (SPMs) of inflammation following supplementation with n-3 fatty acids in humans.
RECENT FINDINGS
A number of reports have measured SPMs in human plasma after n-3 fatty acid supplementation. Although studies have shown some variability in plasma SPM levels, there is strong evidence that a number of resolvins are increased after n-3 fatty acids to concentrations that have been shown to have biological activity. SPM concentrations at the inflammatory site would be expected to be higher than that in blood. SPMs derived from docosapentaenoic acid require further investigation.
SUMMARY
Resolution of inflammation is an active process with SPM playing a vital role in maintaining homeostasis. Studies in humans are providing evidence to suggest that this may be a relevant mechanism that can be stimulated by n-3 fatty acid supplementation. Further research is now required to determine SPM profiles in patients with different chronic conditions and to examine whether supplementation with n-3 fatty acids affects SPMs in relation to their clinical outcome.
Topics: Animals; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Humans; Inflammation; Inflammation Mediators
PubMed: 26655290
DOI: 10.1097/MOL.0000000000000262 -
Lipids in Health and Disease Dec 2015Human hepatocellular cells Hep G2 were used to mimic and investigate the effect of the intake of cadmium (Cd(2+)) contaminated fish on cytotoxicity, fatty acid (FA) and...
Combined incubation of cadmium, docosahexaenoic and eicosapentaenoic acid results in increased uptake of cadmium and elevated docosapentaenoic acid content in hepatocytes in vitro.
BACKGROUND
Human hepatocellular cells Hep G2 were used to mimic and investigate the effect of the intake of cadmium (Cd(2+)) contaminated fish on cytotoxicity, fatty acid (FA) and phospholipid class composition.
METHODS
Cells were incubated with a combination of Cd(2+) and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) fish specific FA.
RESULTS
We measured a significant increased proportion of EPA and DHA in the treated cells compared to the control line confirming the uptake. While doses of 25 μM DHA showed to be toxic to the cells, repeated short term incubations (2 h) at lower doses resulted in an increased uptake of DHA. The resarzurin assay, evaluating cell viability, showed a significant decrease in cell viability between Cd(2+) incubation time and, further, the pre-incubation with BSA-FA complex resulted in significantly increased cell viability. On the metabolic level, increased concentrations of EPA and DHA resulted in an increased proportion of docosapentaenoic acid (DPA) which indicated an increased metabolism. Also 24-h combined incubations of 5 μM Cd(2+) and EPA and DHA showed a significant increase DPA in the total lipid fraction of the cells. In addition, incubation with 5 μM Cd(2+) for 24 h also decreased the total cardiolipin (CL) fraction from the identified phospholipids.
CONCLUSIONS
We confirmed that the applied FA were taken up by the cells. A combination of EPA, DHA and Cd(2+) influenced lysosomal integrity, cell viability and lipid metabolism in the cells. The most important finding is that DHA and EPA reduced the detrimental effect of Cd(2+) on cell viability. The exact effects and kinetics behind our observations still need further evaluation.
Topics: Absorption, Physiological; Animals; Cadmium; Cell Survival; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Unsaturated; Fishes; Food Safety; Hep G2 Cells; Hepatocytes; Humans; Lipid Metabolism; Seafood; Water Pollutants, Chemical
PubMed: 26627047
DOI: 10.1186/s12944-015-0159-2 -
Nutrients Jan 2022The retina requires docosahexaenoic acid (DHA) for optimal function. Alpha-linolenic acid (ALA) and DHA are dietary sources of retinal DHA. This research investigated...
The retina requires docosahexaenoic acid (DHA) for optimal function. Alpha-linolenic acid (ALA) and DHA are dietary sources of retinal DHA. This research investigated optimizing retinal DHA using dietary ALA. Previous research identified 19% DHA in retinal phospholipids was associated with optimal retinal function in guinea pigs. Pregnant guinea pigs were fed dietary ALA from 2.8% to 17.3% of diet fatty acids, at a constant level of linoleic acid (LA) of 18% for the last one third of gestation and retinal DHA levels were assessed in 3-week-old offspring maintained on the same diets as their mothers. Retinal DHA increased in a linear fashion with the maximum on the diet with LA:ALA of 1:1. Feeding diets with LA:ALA of 1:1 during pregnancy and assessing retinal DHA in 3-week-old offspring was associated with optimized retinal DHA levels. We speculate that the current intakes of ALA in human diets, especially in relation to LA intakes, are inadequate to support high DHA levels in the retina.
Topics: Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Diet; Dietary Fats; Docosahexaenoic Acids; Female; Guinea Pigs; Linoleic Acid; Maternal Nutritional Physiological Phenomena; Phospholipids; Pregnancy; Retina; alpha-Linolenic Acid
PubMed: 35057481
DOI: 10.3390/nu14020301 -
The Journal of Biological Chemistry Jan 2023Astrocytic excitatory amino acid transporter 2 (EAAT2) plays a major role in removing the excitatory neurotransmitter L-glutamate (L-Glu) from synaptic clefts in the...
Astrocytic excitatory amino acid transporter 2 (EAAT2) plays a major role in removing the excitatory neurotransmitter L-glutamate (L-Glu) from synaptic clefts in the forebrain to prevent excitotoxicity. Polyunsaturated fatty acids such as docosahexaenoic acid (DHA, 22:6 n-3) enhance synaptic transmission, and their target molecules include EAATs. Here, we aimed to investigate the effect of DHA on EAAT2 and identify the key amino acid for DHA/EAAT2 interaction by electrophysiological recording of L-Glu-induced current in Xenopus oocytes transfected with EAATs, their chimeras, and single mutants. DHA transiently increased the amplitude of EAAT2 but tended to decrease that of excitatory amino acid transporter subtype 1 (EAAT1), another astrocytic EAAT. Single mutation of leucine (Leu) 434 to alanine (Ala) completely suppressed the augmentation by DHA, while mutation of EAAT1 Ala 435 (corresponding to EAAT2 Leu434) to Leu changed the effect from suppression to augmentation. Other polyunsaturated fatty acids (docosapentaenoic acid, eicosapentaenoic acid, arachidonic acid, and α-linolenic acid) similarly augmented the EAAT2 current and suppressed the EAAT1 current. Finally, our docking analysis suggested the most stable docking site is the lipid crevice of EAAT2, in close proximity to the L-Glu and sodium binding sites, suggesting that the DHA/Leu434 interaction might affect the elevator-like slide and/or the shapes of the other binding sites. Collectively, our results highlight a key molecular detail in the DHA-induced regulation of synaptic transmission involving EAATs.
Topics: Docosahexaenoic Acids; Excitatory Amino Acid Transporter 2; Glutamic Acid; Leucine; Synaptic Transmission; Mutation; Xenopus laevis
PubMed: 36509140
DOI: 10.1016/j.jbc.2022.102793 -
Biological & Pharmaceutical Bulletin 2021Long-chain acyl-CoA synthetases (ACSLs) are a family of enzymes that convert long-chain free fatty acids into their active form, acyl-CoAs. Recent knock-out mouse...
Long-chain acyl-CoA synthetases (ACSLs) are a family of enzymes that convert long-chain free fatty acids into their active form, acyl-CoAs. Recent knock-out mouse studies revealed that among ACSL isoenzymes, ACSL6 plays an important role in the maintenance of docosahexaenoic acid (DHA)-containing glycerophospholipids. Several transcript variants of the human ACSL6 gene have been found; the two major ACSL6 variants, ACSL6V1 and V2, encode slightly different short motifs that both contain a conserved structural domain, the fatty acid Gate domain. In the present study, we expressed recombinant human ACSL6V1 and V2 in Spodoptera frugiperda 9 (Sf9) cells using the baculovirus expression system, and then, using our novel ACSL assay system with liquid chromatography-tandem mass spectrometry (LC-MS/MS), we examined the substrate specificities of the recombinant human ACSL6V1 and V2 proteins. The results showed that both ACSL6V1 and V2 could convert various kinds of long-chain fatty acids into their acyl-CoAs. Oleic acid was a good common substrate and eicosapolyenoic acids were poor common substrates for both variants. However, ACSL6V1 and V2 differed considerably in their preferences for octadecapolyenoic acids, such as linoleic acid, and docosapolyenoic acids, such as DHA and docosapentaenoic acid (DPA): ACSL6V1 preferred octadecapolyenoic acids, whereas V2 strongly preferred docosapolyenoic acids. Moreover, our kinetic studies revealed that ACSL6V2 had a much higher affinity for DHA than ACSL6V1. Our results suggested that ACSL6V1 and V2 might exert different physiological functions and indicated that ACSL6V2 might be critical for the maintenance of membrane phospholipids bearing docosapolyenoic acids such as DHA.
Topics: Animals; Coenzyme A Ligases; Docosahexaenoic Acids; Enzyme Assays; Humans; Isoenzymes; Kinetics; Linoleic Acid; Phospholipids; Recombinant Proteins; Sf9 Cells; Spodoptera; Stearic Acids; Substrate Specificity; Tandem Mass Spectrometry
PubMed: 34602568
DOI: 10.1248/bpb.b21-00551