Analysis of Intact Peroxidized Phospholipids from Bovine Retina via LC-MS/MS and GC-MS/MS Using Autoxidized Retina Reference Standards.

Highly unsaturated fatty acids (HUFAs) are vulnerable to oxygen attack, thus making HUFA-rich, high metabolic rate/reactive oxygen species (ROS)-generating neurological tissue particularly susceptible to increased oxidative stress. Lipid oxidation is a putative early stage marker of neurodegenerative diseases, suggesting that reliable monitoring of oxidized neural lipids reveals early pathogenesis. Here, we present a novel methodology to detect and quantify intact ROS-driven peroxidized phospholipids (LPOx-PLs) in bovine retina extract.

Unsaturated Fatty Acid Synthesis Is Associated with Worse Survival and Is Differentially Regulated by and Tumor Suppressor microRNAs in Neuroblastoma.

amplification () and disruption of tumor suppressor microRNA (TSmiR) function are key drivers of poor outcomes in neuroblastoma (NB). While MYCN and TSmiRs regulate glucose metabolism, their role in de novo fatty acid synthesis (FAS) and unsaturated FAS (UFAS) remains poorly understood. Here, we show that FAS and UFAS (U/FAS) genes , , , , and are upregulated in high-risk (HR) NB and that their expression is associated with lower overall survival.

FADS2 function at the major cancer hotspot 11q13 locus alters fatty acid metabolism in cancer.

Dysregulation of fatty acid metabolism and de novo lipogenesis is a key driver of several cancer types through highly unsaturated fatty acid (HUFA) signaling precursors such as arachidonic acid. The human chromosome 11q13 locus has long been established as the most frequently amplified in a variety of human cancers. The fatty acid desaturase genes (FADS1, FADS2 and FADS3) responsible for HUFA biosynthesis localize to the 11q12-13.

Docosahexaenoic Acid Stability in Ready-to-Use Therapeutic Food.

Ready-to-use therapeutic food (RUTF) is used to treat young children diagnosed with severe acute malnutrition. RUTF with low and balanced linoleic and alpha-linolenic acid, plus omega-3 docosahexaenoic acid (DHA), supports long-term cognitive recovery. DHA is prone to degradation due to peroxidation, possibly exacerbated by the iron inherently in RUTF.

Quantitative High-Field NMR- and Mass Spectrometry-Based Fatty Acid Sequencing Reveals Internal Structure in Ru-Catalyzed Deuteration of Docosahexaenoic Acid.

Ru-based catalysis results in highly unsaturated fatty acid (HUFA) ethyl esters (EE) deuterated to various extents. The products carry H (D) mainly at their -allylic positions, where they are resistant to autoxidation compared to natural HUFA and are promising as neurological and retinal drugs. We characterized the extent of deuteration at each allylic position of docosa-4,7,10,13,16,19-hexaenoic acid deuterated to completion at -allylic and allylic positions (D-DHA) by two-dimensional (2D) and high-field (600 and 950 MHz) NMR.

Pharmacokinetics and metabolism in mouse retina of bis-allylic deuterated docosahexaenoic acid (D-DHA), a new dry AMD drug candidate.

Docosahexaenoic acid (DHA; 22:6n-3) rich photoreceptors function in a highly oxidizing microenvironment. Lipid peroxidation and inflammation contribute to initiation and progression of eye diseases including age-related macular degeneration (AMD). Deuteration of DHA at the bis-allylic positions (D-DHA) increases its resilience to oxidative damage in vitro.

Deuterated Arachidonic Acid Ameliorates Lipopolysaccharide-Induced Lung Damage in Mice.

Arachidonic acid (ARA) is a major component of lipid bilayers as well as the key substrate for the eicosanoid cascades. ARA is readily oxidized, and its non-enzymatic and enzymatic oxidation products induce inflammatory responses in nearly all tissues, including lung tissues. Deuteration at bis-allylic positions substantially decreases the overall rate of ARA oxidation when hydrogen abstraction is an initiating event.

Deuterated docosahexaenoic acid protects against oxidative stress and geographic atrophy-like retinal degeneration in a mouse model with iron overload.

Oxidative stress plays a central role in age-related macular degeneration (AMD). Iron, a potent generator of hydroxyl radicals through the Fenton reaction, has been implicated in AMD. One easily oxidized molecule is docosahexaenoic acid (DHA), the most abundant polyunsaturated fatty acid in photoreceptor membranes.

Single-cell chromatin accessibility and lipid profiling reveals SCD1-dependent metabolic shift in adipocytes induced by bariatric surgery.

Obesity promotes type 2 diabetes and cardiometabolic pathologies. Vertical sleeve gastrectomy (VSG) is used to treat obesity resulting in long-term weight loss and health improvements that precede weight loss; however, the mechanisms underlying the immediate benefits remain incompletely understood. Because adipose plays a crucial role in energy homeostasis and utilization, we hypothesized that VSG exerts its influences, in part, by modulating adipose functional states.

Low linoleic acid foods with added DHA given to Malawian children with severe acute malnutrition improve cognition: a randomized, triple-blinded, controlled clinical trial.

Background: There is concern that the PUFA composition of ready-to-use therapeutic food (RUTF) for the treatment of severe acute malnutrition (SAM) is suboptimal for neurocognitive recovery.

Objectives: We tested the hypothesis that RUTF made with reduced amounts of linoleic acid, achieved using high-oleic (HO) peanuts without added DHA (HO-RUTF) or with added DHA (DHA-HO-RUTF), improves cognition when compared with standard RUTF (S-RUTF).

Methods: A triple-blind, randomized, controlled clinical feeding trial was conducted among children with uncomplicated SAM in Malawi with 3 types of RUTF: DHA-HO-RUTF, HO-RUTF, and S-RUTF.

The aromatase inhibitor letrozole restores FADS2 function in ER+ MCF7 human breast cancer cells.

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.

Polyunsaturated fatty acid biosynthesis pathway and genetics. implications for interindividual variability in prothrombotic, inflammatory conditions such as COVID-19.

COVID-19 symptoms vary from silence to rapid death, the latter mediated by both a cytokine storm and a thrombotic storm. SARS-CoV (2003) induces Cox-2, catalyzing the synthesis, from highly unsaturated fatty acids (HUFA), of eicosanoids and docosanoids that mediate both inflammation and thrombosis. HUFA balance between arachidonic acid (AA) and other HUFA is a likely determinant of net signaling to induce a healthy or runaway physiological response.

Fatty acid desaturase 2 (FADS2) but not FADS1 desaturates branched chain and odd chain saturated fatty acids.

Branched chain fatty acids (BCFA) and linear chain/normal odd chain fatty acids (n-OCFA) are major fatty acids in human skin lipids, especially sebaceous gland (SG) wax esters. Skin lipids contain variable amounts of monounsaturated BCFA and n-OCFA, in some reports exceeding over 20% of total fatty acids. Fatty acid desaturase 2 (FADS2) codes for a multifunctional enzyme that catalyzes Δ4-, Δ6- and Δ8-desaturation towards ten unsaturated fatty acids but only one saturate, palmitic acid, converting it to 16:1n-10; FADS2 is not active towards 14:0 or 18:0.

Structural Identification of Monounsaturated Branched Chain Fatty Acid Methyl Esters by Combination of Electron Ionization and Covalent Adduct Chemical Ionization Tandem Mass Spectrometry.

Monounsaturated fatty acids (-MUFA) and saturated branched chain fatty acids (BCFA) are structurally characterized by separate tandem mass spectrometry methods for double bond localization and for chain branching in their respective fatty acid methyl ester (FAME) derivatives; however, these methods have never been applied to branched monounsaturated FAME. Here, we report application of electron ionization (EI)-MS/MS and solvent-mediated covalent adduct chemical ionization (CACI)-MS/MS of monounsaturated BCFA methyl esters (MUBCFAME) of a chain length of 15-20 carbons. A novel system was used to implement CI with low vapor pressure reagents in a tabletop triple quadrupole MS.

Potentially High Value Conjugated Linolenic Acids (CLnA) in Melon Seed Waste.

Conjugated linolenic acids (CLnAs) are natural phytochemicals with known and potential bioactivities in mammals. Established CLnA sources are limited to a few common fruit seeds, notably pomegranate seeds and cherry pits, and the search for alternatives is impeded in part by cumbersome methods for reliable measurement. We investigated CLnA contents in lower value fruit seeds with a recently available facile mass spectrometry method, solvent-mediated chemical ionization, enabling and quantitative analysis.

Identification of genes mediating branched chain fatty acid elongation.

Saturated branched chain fatty acids (BCFA) terminating with either a prop-2-yl (iso) or sec-butan-2-yl (anteiso) group are common bioactive food components consumed from beef, fish, and dairy products. Little is known about the endogenous metabolism of BCFA and the enzymes mediating their interconversions. By using transient transfection studies, we report for the first time the substrate specificity of the elongase of very long chain fatty acids (ELOVL)1-7 toward anteiso-15:0 and iso-18:0, and assessed competition between BCFA and normal saturated fatty acids (n-SFA).

Glycerol derived process contaminants in refined coconut oil induce cholesterol synthesis in HepG2 cells.

Despite its 50-year history, the conventional diet-heart hypothesis holding that dietary saturated fats raise serum cholesterol, and with it, cardiovascular risk, remains controversial. Harsh chemical and physical treatment generates process contaminants, and refined oils raise serum and tissue cholesterol in vivo independent of saturated fat content. We developed an in vitro bioassay for rapidly assessing the influence of oils on cholesterol metabolism in the human liver HepG2 cell line, and tested it using coconut oil (CO) of various stages of refinement.

A novel FADS2 isoform identified in human milk fat globule suppresses FADS2 mediated Δ6-desaturation of omega-3 fatty acids.

Introduction: The only known non-pharmacological means to alter long chain polyunsaturated fatty acid (LCPUFA) abundance in mammalian tissue is by altering substrate fatty acid ratios. Alternative mRNA splicing is increasingly recognized as a modulator of protein structure and function. Here we report identification of a novel alternative transcript (AT) of fatty acid desaturase 2 (FADS2) that inhibits production of omega-3 but not omega-6 LCPUFA, discovered during study of ATs in human milk fat globules (MFG).

The role of fatty acid desaturase (FADS) genes in oleic acid metabolism: FADS1 Δ7 desaturates 11-20:1 to 7,11-20:2.

Introduction: In mammals, FADS2 catalyzes "front-end" Δ4-, Δ6-, and Δ8-desaturation of fatty acyl chains, whereas FADS1 has Δ5-desaturase activity. Eighteen and 20-carbon precursors to highly unsaturated n-3 and n-6 fatty acids are the usual substrates for FADS1 and FADS2. Our main objective was to characterize the metabolic fate of oleic acid (OA) due to action of FADS gene products.

BCFA-enriched vernix-monoacylglycerol reduces LPS-induced inflammatory markers in human enterocytes in vitro.

BackgroundExcess vernix caseosa produced by the fetal skin appears as particles suspended in the amniotic fluid in late gestation, is swallowed by the fetus, and is found throughout the newborn gastrointestinal tract as the first organisms are arriving to colonize the gut. Lipid-rich vernix contains an unusually high 29% branched chain fatty acids (BCFA). BCFAs reduce the incidence of necrotizing enterocolitis in an animal model, and were recently found predominantly in the sn-2 position of human milk triacylglycerols.

Human fetal intestinal epithelial cells metabolize and incorporate branched chain fatty acids in a structure specific manner.

Background: Branched chain fatty acids (BCFA) are constituents of gastrointestinal (GI) tract in healthy newborn human infants, reduce the incidence of necrotizing enterocolitis (NEC) in a neonatal rat model, and are incorporated into small intestine cellular lipids in vivo. We hypothesize that BCFA are taken up, metabolized and incorporated into human fetal cells in vitro.

Methods: Human H4 cells, a fetal non-transformed primary small intestine cell line, were incubated with albumin-bound non-esterified anteiso-17:0, iso-16:0, iso-18:0 and/or iso-20:0, and FA profiles in lipid fractions were analyzed.

Metabolic fate of docosahexaenoic acid (DHA; 22:6n-3) in human cells: direct retroconversion of DHA to eicosapentaenoic acid (20:5n-3) dominates over elongation to tetracosahexaenoic acid (24:6n-3).

Docosahexaenoic acid (22:6n-3) supplementation in humans causes eicosapentaenoic acid (20:5n-3) levels to rise in plasma, but not in neural tissue where 22:6n-3 is the major omega-3 in phospholipids. We determined whether neuronal cells (Y79 and SK-N-SH) metabolize 22:6n-3 differently from non-neuronal cells (MCF7 and HepG2). We observed that (13) C-labeled 22:6n-3 was primarily esterified into cell lipids.

Alternative splicing generates novel Fads3 transcript in mice.

Fads3 is the third member of the fatty acid desaturase gene cluster; with at least eight evolutionarily conserved alternative transcripts (AT), having no clearly established function as are known for FADS2 and FADS1. Here we present identification of a novel Fads3 transcript in mice (Fads3AT9), characterize Fads3AT9 expression in mouse tissues and evaluate correlations with metabolite profiles. Total RNA obtained from mouse tissues is reverse-transcribed into cDNA and used as template for PCR reactions.