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International Journal of Molecular... Jun 2023Neurodegenerative diseases are characterized by neuroinflammation, neuronal depletion and oxidative stress. They coincide with subtle chronic or flaring inflammation,... (Review)
Review
Neurodegenerative diseases are characterized by neuroinflammation, neuronal depletion and oxidative stress. They coincide with subtle chronic or flaring inflammation, sometimes escalating with infiltrations of the immune system cells in the inflamed parts causing mild to severe or even lethal damage. Thus, neurodegenerative diseases show all features of autoimmune diseases. Prevalence of neurodegenerative diseases has dramatically increased in recent decades and unfortunately, the therapeutic efficacy and safety profile of available drugs is moderate. The beneficial effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) polyunsaturated fatty acids (omega-3 PUFAs) are nowadays highlighted by a plethora of studies. They play a role in suppression of inflammation, gene expression, cellular membrane fluidity/permeability, immune functionality and intracellular/exocellular signaling. The role of omega-6 polyunsaturated fatty acids, such as linoleic acid (LA), gamma linolenic acid (GLA), and arachidonic acid (AA), on neuroprotection is controversial, as some of these agents, specifically AA, are proinflammatory, whilst current data suggest that they may have neuroprotective properties as well. This review provides an overview of the existing recent clinical studies with respect to the role of omega-3 and omega-6 PUFAs as therapeutic agents in chronic, inflammatory, autoimmune neurodegenerative diseases as well as the dosages and the period used for testing.
Topics: Humans; Eicosapentaenoic Acid; Docosahexaenoic Acids; Neurodegenerative Diseases; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Arachidonic Acid; Linoleic Acids; Inflammation
PubMed: 37445890
DOI: 10.3390/ijms241310717 -
European Journal of Medical Research Jul 2023Flaxseed (Linum usitatissimum L) is an ancient perennial plant species regarded as a multipurpose plant owing to its richness in omega-3 polyunsaturated fatty acids... (Review)
Review
Flaxseed (Linum usitatissimum L) is an ancient perennial plant species regarded as a multipurpose plant owing to its richness in omega-3 polyunsaturated fatty acids (PUFA) including α-linolenic acid (ALA). The extensive biochemical analysis of flaxseed resulted in the identification of its bioactive, i.e., lignans with potential application in the improvement of human health. Flaxseed oil, fibers, and lignans exert potential health benefits including reduction of cardiovascular disease, atherosclerosis, diabetes, cancer, arthritis, osteoporosis, and autoimmune and neurological disorders that have led to the diversification of flaxseed plant applications. This comprehensive review focuses on flaxseed oil as the major product of flaxseed with emphasis on the interrelationship between its chemical composition and biological effects. Effects reviewed include antioxidant, anti-inflammatory, antimicrobial, anticancer, antiulcer, anti-osteoporotic, cardioprotective, metabolic, and neuroprotective. This study provides an overview of flaxseed oil effects with the reported action mechanisms related to its phytochemical composition and in comparison, to other PUFA-rich oils. This study presents the most updated and comprehensive review summarizing flaxseed oil's health benefits for the treatment of various diseases.
Topics: Humans; Linseed Oil; Flax; Cardiovascular Diseases; Antioxidants; Lignans
PubMed: 37464425
DOI: 10.1186/s40001-023-01203-6 -
Journal of Translational Medicine Jun 2023Acute-on-chronic liver failure (ACLF) is a severe syndrome with high short-term mortality, but the pathophysiology still remains largely unknown. Immune dysregulation...
BACKGROUND
Acute-on-chronic liver failure (ACLF) is a severe syndrome with high short-term mortality, but the pathophysiology still remains largely unknown. Immune dysregulation and metabolic disorders contribute to the progression of ACLF, but the crosstalk between immunity and metabolism during ACLF is less understood. This study aims to depict the immune microenvironment in the liver during ACLF, and explore the role of lipid metabolic disorder on immunity.
METHODS
Single-cell RNA-sequencing (scRNA-seq) was performed using the liver non-parenchymal cells (NPCs) and peripheral blood mononuclear cells (PBMCs) from healthy controls, cirrhosis patients and ACLF patients. A series of inflammation-related cytokines and chemokines were detected using liver and plasma samples. The lipid metabolomics targeted free fatty acids (FFAs) in the liver was also detected.
RESULTS
The scRNA-seq analysis of liver NPCs showed a significant increase of monocytes/macrophages (Mono/Mac) infiltration in ACLF livers, whereas the resident Kupffer cells (KCs) were exhausted. A characterized TREM2 Mono/Mac subpopulation was identified in ACLF, and showed immunosuppressive function. Combined with the scRNA-seq data from PBMCs, the pseudotime analysis revealed that the TREM2 Mono/Mac were differentiated from the peripheral monocytes and correlated with lipid metabolism-related genes including APOE, APOC1, FABP5 and TREM2. The targeted lipid metabolomics proved the accumulation of unsaturated FFAs associated with α-linolenic acid (α-LA) and α-LA metabolism and beta oxidation of very long chain fatty acids in the ACLF livers, indicating that unsaturated FFAs might promote the differentiation of TREM2 Mono/Mac during ACLF.
CONCLUSIONS
The reprogramming of macrophages was found in the liver during ACLF. The immunosuppressive TREM2 macrophages were enriched in the ACLF liver and contributed to the immunosuppressive hepatic microenvironment. The accumulation of unsaturated FFAs in the ACLF liver promoted the reprogramming of the macrophages. It might be a potential target to improve the immune deficiency of ACLF patients through regulating lipid metabolism.
Topics: Humans; Lipid Metabolism; Acute-On-Chronic Liver Failure; Hepatitis B virus; Leukocytes, Mononuclear; Macrophages; Fatty Acid-Binding Proteins
PubMed: 37380987
DOI: 10.1186/s12967-023-04294-1 -
Metabolites Jul 2023Phytohormones exhibit a wide range of chemical structures, though they primarily originate from three key metabolic precursors: amino acids, isoprenoids, and lipids.... (Review)
Review
Phytohormones exhibit a wide range of chemical structures, though they primarily originate from three key metabolic precursors: amino acids, isoprenoids, and lipids. Specific amino acids, such as tryptophan, methionine, phenylalanine, and arginine, contribute to the production of various phytohormones, including auxins, melatonin, ethylene, salicylic acid, and polyamines. Isoprenoids are the foundation of five phytohormone categories: cytokinins, brassinosteroids, gibberellins, abscisic acid, and strigolactones. Furthermore, lipids, i.e., α-linolenic acid, function as a precursor for jasmonic acid. The biosynthesis routes of these different plant hormones are intricately complex. Understanding of these processes can greatly enhance our knowledge of how these hormones regulate plant growth, development, and physiology. This review focuses on detailing the biosynthetic pathways of phytohormones.
PubMed: 37623827
DOI: 10.3390/metabo13080884 -
International Journal of Molecular... Sep 2023Cardiovascular diseases (CVDs) represent the leading cause of global mortality with 1.7 million deaths a year. One of the alternative systems to drug therapy to minimize... (Review)
Review
Cardiovascular diseases (CVDs) represent the leading cause of global mortality with 1.7 million deaths a year. One of the alternative systems to drug therapy to minimize the risk of CVDs is represented by alpha-linolenic acid (ALA), an essential fatty acid of the omega-3 series, known for its cholesterol-lowering effect. The main purpose of this review is to analyze the effects of ALA and investigate the relevant omega-6/omega-3 ratio in order to maintain functionally beneficial effects. Concerning the lipid-lowering preventive effects, ALA may favorably affect the values of LDL-C and triglycerides in both adult and pediatric populations. Furthermore, ALA has shown protective effects against hypertension, contributing to balancing blood pressure through customary diet. According to the 2009 EFSA statement, dietary ALA may contribute to reducing the risk of CVDs, thanks to anti-hypertensive, anti-atherosclerotic and cardioprotective effects.
Topics: Adult; Child; Humans; alpha-Linolenic Acid; Fatty Acids, Omega-3; Hypertension; Antihypertensive Agents; Cardiovascular Diseases
PubMed: 37762621
DOI: 10.3390/ijms241814319 -
Biomolecules Aug 2023Sepsis is triggered by microbial infection, injury, or even major surgery. Both innate and adaptive immune systems are involved in its pathogenesis. Cytoplasmic presence... (Review)
Review
Sepsis is triggered by microbial infection, injury, or even major surgery. Both innate and adaptive immune systems are involved in its pathogenesis. Cytoplasmic presence of DNA or RNA of the invading organisms or damaged nuclear material (in the form of micronucleus in the cytoplasm) in the host cell need to be eliminated by various nucleases; failure to do so leads to the triggering of inflammation by the cellular cGAS-STING system, which induces the release of IL-6, TNF-α, and IFNs. These cytokines activate phospholipase A2 (PLA2), leading to the release of polyunsaturated fatty acids (PUFAs), gamma-linolenic acid (GLA), arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), which form precursors to various pro- and anti-inflammatory eicosanoids. On the other hand, corticosteroids inhibit PLA2 activity and, thus, suppress the release of GLA, AA, EPA, and DHA. PUFAs and their metabolites have a negative regulatory action on the cGAS-STING pathway and, thus, suppress the inflammatory process and initiate inflammation resolution. Pro-inflammatory cytokines and corticosteroids (corticosteroids > IL-6, TNF-α) suppress desaturases, which results in decreased formation of GLA, AA, and other PUFAs from the dietary essential fatty acids (EFAs). A deficiency of GLA, AA, EPA, and DHA results in decreased production of anti-inflammatory eicosanoids and failure to suppress the cGAS-STING system. This results in the continuation of the inflammatory process. Thus, altered concentrations of PUFAs and their metabolites, and failure to suppress the cGAS-STING system at an appropriate time, leads to the onset of sepsis. Similar abnormalities are also seen in radiation-induced inflammation. These results imply that timely administration of GLA, AA, EPA, and DHA, in combination with corticosteroids and anti-IL-6 and anti-TNF-α antibodies, may be of benefit in mitigating radiation-induced damage and sepsis.
Topics: Humans; Tumor Necrosis Factor-alpha; Interleukin-6; Tumor Necrosis Factor Inhibitors; Inflammation; Fatty Acids, Unsaturated; Eicosanoids; Eicosapentaenoic Acid; Arachidonic Acid; Cytokines; Docosahexaenoic Acids; Anti-Inflammatory Agents; Sepsis
PubMed: 37759732
DOI: 10.3390/biom13091332 -
The European Respiratory Journal Oct 2023Eicosanoids are bioactive lipids that regulate systemic inflammation and exert vasoactive effects. Specific eicosanoid metabolites have previously been associated with...
BACKGROUND
Eicosanoids are bioactive lipids that regulate systemic inflammation and exert vasoactive effects. Specific eicosanoid metabolites have previously been associated with pulmonary hypertension (PH), yet their role remains incompletely understood.
METHODS
We studied 482 participants with chronic dyspnoea who underwent clinically indicated cardiopulmonary exercise testing (CPET) with invasive haemodynamic monitoring. We performed comprehensive profiling of 888 eicosanoids and eicosanoid-related metabolites using directed non-targeted mass spectrometry, and examined associations with PH (mean pulmonary arterial pressure (mPAP) >20 mmHg), PH subtypes and physiological correlates, including transpulmonary metabolite gradients.
RESULTS
Among 482 participants (mean±sd age 56±16 years, 62% women), 200 had rest PH. We found 48 eicosanoids and eicosanoid-related metabolites that were associated with PH. Specifically, prostaglandin (11β-dhk-PGF2α), linoleic acid (12,13-EpOME) and arachidonic acid derivatives (11,12-DiHETrE) were associated with higher odds of PH (false discovery rate q<0.05 for all). By contrast, epoxide (8(9)-EpETE), α-linolenic acid (13()-HOTrE(γ)) and lipokine derivatives (12,13-DiHOME) were associated with lower odds. Among PH-related eicosanoids, 14 showed differential transpulmonary metabolite gradients, with directionality suggesting that metabolites associated with lower odds of PH also displayed pulmonary artery uptake. In individuals with exercise PH, eicosanoid profiles were intermediate between no PH and rest PH, with six metabolites that differed between rest and exercise PH.
CONCLUSIONS
Our findings highlight the role of specific eicosanoids, including linoleic acid and epoxide derivatives, as potential regulators of inflammation in PH. Of note, physiological correlates, including transpulmonary metabolite gradients, may prioritise future studies focused on eicosanoid-related pathways as important contributors to PH pathogenesis.
Topics: Humans; Female; Adult; Middle Aged; Aged; Male; Hypertension, Pulmonary; Linoleic Acid; Eicosanoids; Inflammation; Epoxy Compounds
PubMed: 37857430
DOI: 10.1183/13993003.00561-2023 -
Journal of Personalized Medicine Feb 2024α-linolenic acid (ALA), which is a member of the n-3 polyunsaturated fatty acid (n-3 PUFA) family, has often been ignored due to a lack of information. ALA has... (Review)
Review
α-linolenic acid (ALA), which is a member of the n-3 polyunsaturated fatty acid (n-3 PUFA) family, has often been ignored due to a lack of information. ALA has gradually attracted increased attention due to its nutritional and medicinal advantages. Studies have shown that ALA exerts beneficial effects on a variety of diseases, including cancer. In this review, we summarize the antitumor effects of ALA in the context of cell biology, including the inhibition of proliferation, the induction of apoptosis, the inhibition of metastasis and angiogenesis, and antioxidant effects. In addition, studies have shown that ALA can be used as a drug carrier or exert positive clinical effects when combined with drugs. Therefore, the use of ALA in clinical treatments is very promising and valuable.
PubMed: 38541002
DOI: 10.3390/jpm14030260 -
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