Phospholipid Subclasses Research Articles

Identification of Phospholipids Relevant to Cancer Tissue Using Differential Ion Mobility Spectrometry

Phospholipids are the main building components of cell membranes and are also used for cell signaling and as energy storages. Cancer cells alter their lipid metabolism, which ultimately leads to an increase in phospholipids in cancer tissue. Surgical energy instruments use electrical or vibrational energy to heat tissues, which causes intra- and extracellular water to expand rapidly and degrade cell structures, bursting the cells, which causes the formation of a tissue aerosol or smoke depending on the amount of energy used. This gas phase analyte can then be analyzed via gas analysis methods. Differential mobility spectrometry (DMS) is a method that can be used to differentiate malignant tissue from benign tissues in real time via the analysis of surgical smoke produced by energy instruments. Previously, the DMS identification of cancer tissue was based on a ‘black box method’ by differentiating the 2D dispersion plots of samples. This study sets out to find datapoints from the DMS dispersion plots that represent relevant target molecules. We studied the ability of DMS to differentiate three subclasses of phospholipids (phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine) from a control sample using a bovine skeletal muscle matrix with a 5 mg addition of each phospholipid subclass to the sample matrix. We trained binary classifiers using linear discriminant analysis (LDA) and support vector machines (SVM) for sample classification. We were able to identify phosphatidylcholine, -inositol, and -ethanolamine with SVM binary classification accuracies of 91%, 73%, and 66% and with LDA binary classification accuracies of 82%, 74%, and 72%, respectively. Phosphatidylcholine was detected with a reliable classification accuracy, but ion separation setups should be adjusted in future studies to reliably detect other relevant phospholipids such as phosphatidylinositol and phosphatidylethanolamine and improve DMS as a microanalysis method and identify other phospholipids relevant to cancer tissue.

Dietary Milk Phospholipids Increase Body Fat and Modulate Gut Permeability, Systemic Inflammation, and Lipid Metabolism in Mice

The study aimed at how dietary milk polar lipids affect gut permeability, systemic inflammation, and lipid metabolism during diet-induced obesity (DIO). C57BL/6J mice (n = 6x3) were fed diets with 34% fat as energy for 15 weeks: (1) modified AIN-93G diet (CO); (2) CO with milk gangliosides (GG); (3) CO with milk phospholipids (MPL). Gut permeability was assessed by FITC-dextran and sugar absorption tests. Intestinal tight junction proteins were evaluated by Western blot. Plasma cytokines were measured by immunoassay. Body composition was assessed by magnetic resonance imaging. Tissue lipid profiles were obtained by thin layer chromatography. Hepatic expression of genes associated with lipid metabolism was assessed by RT-qPCR. MPL increased the efficiency of converting food into body fat and facilitated body fat accumulation compared with CO. MPL and GG did not affect fasting glucose or HOMA-IR during DIO. MPL increased while GG decreased plasma TG compared with CO. MPL decreased phospholipids subclasses in the muscle while increased those in the liver compared with CO. GG and MPL had little effect on hepatic expression of genes associated with lipid metabolism. Compared with CO, MPL decreased polar lipids content in colon mucosa. Small intestinal permeability decreased while colon permeability increased and then recovered during the feeding period. High-fat feeding increased plasma endotoxin after DIO but did not affect plasma cytokines. MPL and GG did not affect plasma endotoxin, adipokines and inflammatory cytokines. After the establishment of obesity, MPL increased gut permeability to large molecules but decreased intestinal absorption of small molecules while GG tended to have the opposite effects. MPL and GG decreased mannitol and sucralose excretions, which peaked at d 45 in the CO group. MPL decreased occludin in jejunum mucosa compared with CO. GG and MPL did not affect zonula occludens-1 in gut mucosa. In conclusion, during DIO, milk GG decreased gut permeability, and had little effect on systemic inflammation and lipid metabolism; MPL facilitated body fat accumulation, decreased gut permeability, did not affect systemic inflammation.

Cannabigerol-A useful agent restoring the muscular phospholipids milieu in obese and insulin-resistant Wistar rats?

Numerous strategies have been proposed to minimize obesity-associated health effects, among which phytocannabinoids appear to be effective and safe compounds. In particular, cannabigerol (CBG) emerges as a potent modulator of the composition of membrane phospholipids (PLs), which plays a critical role in the development of insulin resistance. Therefore, here we consider the role of CBG treatment on the composition of PLs fraction with particular emphasis on phospholipid subclasses (e.g., phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), and phosphatidylinositol (PI)) in the red gastrocnemius muscle of Wistar rats fed the standard or high-fat, high-sucrose (HFHS) diet. The intramuscular PLs content was determined by gas-liquid chromatography and based on the composition of individual FAs, we assessed the stearoyl-CoA desaturase 1 (SCD1) index as well as the activity of n-3 and n-6 polyunsaturated fatty acids (PUFAs) pathways. Expression of various proteins engaged in the inflammatory pathway, FAs elongation, and desaturation processes was measured using Western blotting. Our research has demonstrated the important association of obesity with alterations in the composition of muscular PLs, which was significantly improved by CBG supplementation, enriching the lipid pools in n-3 PUFAs and decreasing the content of arachidonic acid (AA), which in turn influenced the activity of PUFAs pathways in various PLs subclasses. CBG also inhibited the local inflammation development and profoundly reduced the SCD1 activity. Collectively, restoring the PLs homeostasis of the myocyte membrane by CBG indicates its new potential medical application in the treatment of obesity-related metabolic disorders.

Lambda-cyhalothrin'nin Oreochromis niloticus’un Solungaç Fosfolipid (PL) Alt Sınıfı Üzerine Etkisi

Fatty acids have a crucial role in providing energy and performing essential functions in living organisms. Moreover, these substances exhibit the most significant alterations in their structure based on ecotoxicological parameters when viewed from a biochemical perspective. These bioactive chemicals are present in the cellular architecture. The study of these fatty acids, crucial for maintaining the integrity and permeability of cell membranes, holds great significance for all living organisms. Consequently, doing fatty acid analysis specifically at the phospholipid level holds significant importance.
 The impact of lambda cyhalothrin on the fatty acid content of several phospholipid subclasses (phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS) in the gill tissue of O. niloticus (Perciformes: Cichlidae) was assessed using gas chromatography. The alterations in the fatty acid composition was analyzed 21 days after exposure.
 Following the complete extraction of lipids from gill tissue, the tissue was subsequently separated into different subclasses of phospholipids using thin layer chromatography. The samples were subjected to methylation and then evaluated using Gas Chromatography to determine the percentage of the fatty acid. After doing the analysis, a grand total of 16 fatty acids were identified. The research revealed that the primary fatty acids were 16:0 and 18:0 of saturated fatty acids, monounsaturated 18:1n-9, and polyunsaturated 18:2n-6, 20:4n-6, and 22:6n-6. Upon analyzing the distribution of fatty acids, it was observed that PC, PE, and PI included 16:0, PE contained 18:1, PE and PS contained C18:2n-6 and 20:4n-6, and significant alterations in C22:6n-3 were detected in PE. Our investigation revealed that the n-3/n-6 ratio of fish in the PE subclass was the lowest when compared to PC, PI, and PS.

Phosphatidylthreonine is a procoagulant lipid detected in human blood and elevated in coronary artery disease

Aminophospholipids (aPL) such as phosphatidylserine are essential for supporting the activity of coagulation factors, circulating platelets, and blood cells. Phosphatidylthreonine (PT) is an aminophospholipid previously reported in eukaryotic parasites and animal cell cultures, but not yet in human tissues. Here, we evaluated whether PT is present in blood cells and characterized its ability to support coagulation. Several PT molecular species were detected in human blood, washed platelets, extracellular vesicles, and isolated leukocytes from healthy volunteers using liquid chromatography–tandem mass spectrometry. The ability of PT to support coagulation was demonstrated in vitro using biochemical and biophysical assays. In liposomes, PT supported prothrombinase activity in the presence and absence of phosphatidylserine. PT nanodiscs strongly bound FVa and lactadherin (nM affinity) but poorly bound prothrombin and FX, suggesting that PT supports prothrombinase through recruitment of FVa. PT liposomes bearing tissue factor poorly generated thrombin in platelet poor plasma, indicating that PT poorly supports extrinsic tenase activity. On platelet activation, PT is externalized and partially metabolized. Last, PT was significantly higher in platelets and extracellular vesicle from patients with coronary artery disease than in healthy controls. In summary, PT is present in human blood, binds FVa and lactadherin, supports coagulation in vitro through FVa binding, and is elevated in atherosclerotic vascular disease. Our studies reveal a new phospholipid subclass, that contributes to the procoagulant membrane, and may support thrombosis in patients at elevated risk.

Study on lipid and phospholipid composition from the seed oil of Dalbergia tonkinensis

The content and composition of classes and molecular species of phospholipid extracted from Dalbergia tonkinensis Prain (Cây Sưa) seed oil in Viet Nam have been investigated using HPLC-HRMS and LCMS-IT-TOF. The content of phospholipid subclasses and their molecular species of D. tonkinensis seed oil have been investigated for the first time. The results showed that D. tonkinensis seed oil contains all basic classes of lipid: polar lipid, sterol, triacylglycerol, free fatty acid, diacylglycerol, hydrocarbon, and wax. In which, the content of triacylglycerol accounts for the highest percentage of 76.38 %, while polar lipid and free fatty acid also have a relatively high content. This result indicated the presence of 12 specific phospholipid subclasses of the plant, including phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol. The "molecular forms" of phospholipids of Sua seeds lipids have been identified. The results show that the phospholipids of Sua seeds have 3 classes of substances including phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylinositol (PI). In which PE has 5 molecular forms, PC has 5 molecular forms and has 2 molecular forms of PI. These are the first data was found and published in Sua seeds.

Prenatal Choline Supplement in a Maternal Obesity Model Modulates Offspring Hepatic Lipidomes.

Maternal obesity during pregnancy adversely impacts offspring health, predisposing them to chronic metabolic diseases characterized by insulin resistance, dysregulated macronutrient metabolism, and lipid overload, such as metabolic-associated fatty liver disease (MAFLD). Choline is a semi-essential nutrient involved in lipid and one-carbon metabolism that is compromised during MAFLD progression. Here, we investigated under high-fat (HF) obesogenic feeding how maternal choline supplementation (CS) influenced the hepatic lipidome of mouse offspring. Our results demonstrate that maternal HF+CS increased relative abundance of a subclass of phospholipids called plasmalogens in the offspring liver at both embryonic day 17.5 and after 6 weeks of postnatal HF feeding. Consistent with the role of plasmalogens as sacrificial antioxidants, HF+CS embryos were presumably protected with lower oxidative stress. After postnatal HF feeding, the maternal HF+CS male offspring also had higher relative abundance of both sphingomyelin d42:2 and its side chain, nervonic acid (FA 24:1). Nervonic acid is exclusively metabolized in the peroxisome and is tied to plasmalogen synthesis. Altogether, this study demonstrates that under the influence of obesogenic diet, maternal CS modulates the fetal and postnatal hepatic lipidome of male offspring, favoring plasmalogen synthesis, an antioxidative response that may protect the mouse liver from damages due to HF feeding.

Plasmalogens and platelet-activating factor roles in chronic inflammatory diseases.

Fatty acids and phospholipid molecules are essential for determining the structure and function of cell membranes, and they hence participate in many biological processes. Platelet activating factor (PAF) and its precursor plasmalogen, which represent two subclasses of ether phospholipids, have attracted increasing research attention recently due to their association with multiple chronic inflammatory, neurodegenerative, and metabolic disorders. These pathophysiological conditions commonly involve inflammatory processes linked to an excess presence of PAF and/or decreased levels of plasmalogens. However, the molecular mechanisms underlying the roles of plasmalogens in inflammation have remained largely elusive. While anti-inflammatory responses most likely involve the plasmalogen signal pathway; pro-inflammatory responses recruit arachidonic acid, a precursor of pro-inflammatory lipid mediators which is released from membrane phospholipids, notably derived from the hydrolysis of plasmalogens. Plasmalogens per se are vital membrane phospholipids in humans. Changes in their homeostatic levels my alter cell membrane properties, thus affecting key signaling pathways that mediate inflammatory cascades and immune responses. The plasmalogen analogs of PAF are also potentially important, considering that anti-PAF activity has strong anti-inflammatory effects. Plasmalogen replacement therapy was further identified as a promising anti-inflammatory strategy allowing for the relief of pathological hallmarks in patients affected by chronic diseases with an inflammatory component. The aim of this Short Review is to highlight the emerging roles and implications of plasmalogens in chronic inflammatory disorders, along with the promising outcomes of plasmalogen replacement therapy for the treatment of various PAF-related chronic inflammatory pathologies.

Shift in phospholipid and fatty acid contents accompanies brain myelination

In the central nervous system, lipids represent approximately 70% of myelin dry weight and play a key role in axon insulation and action potential conduction velocity. Lipids may thus represent sensitive markers of myelin status in physiological and pathological contexts. In this study, a comprehensive lipidomic analysis by ultra-high-performance liquid chromatography and high-resolution mass spectrometry was performed on myelin-enriched fractions prepared from mouse brains. Two developmental stages were compared: an early rapid myelination stage (postnatal day 15, P15), and a late basal myelination stage (P40). Besides an expected enrichment in characteristic myelin lipids, our study revealed a profound remodeling in phospholipid subclasses during myelination. It included a dramatic decrease in phosphatidylcholine (PC) content and an increase in phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI) contents, concomitant to an increased proportion of monounsaturated fatty acids (MUFA) in these subclasses. Lipidomic results were supported by upregulated expression of genes involved in PE, PI, PS and MUFA synthesis in maturing O4+ oligodendrocytes. Highlighted lipid changes may represent key features of brain myelination that could be explored in the context of myelin pathologies.

Fatty acid, the lipid classes, phospholipid composition of the mussels \(\textit{Beguina semiorbiculata}\) from Nam Du and Phu Quoc islands, Kien Giang province, Vietnam

This study aims to analyze compositions of lipid classes, phospholipid subclasses and fatty acids in two mussels, Beguina semiorbiculata, harvested from Nam Du and Phu Quoc islands, Kien Giang province. The obtained results indicated that the total lipid contents of the B. semiorbiculata harvested in Nam Du and Phu Quoc islands were 0.48% and 0.63% of wet weight, respectively, and contained six classes: Hydrocarbon and wax (HW), triacylglycerol (TAG), free fatty acids (FFA), sterol (ST), polar lipid (PoL), and monoalkyl diacylglycerol (MADAG). Two main classes in the total lipid content of two studied mussels were triacylglycerol (TG) (38.22% and 41.27%) and polar lipid (PL) (27.02% and 30.46%). PL of both muselles consited of five types: Phosphatidylethalnolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI) and ceramide aminoethylphosphonate (CAEP) in which phosphatidylethanolamine (PE) (34.34% and 37.08%) and phosphatidylcholine (PC) (26.32% and 26.54%) were dominated. The content of polyunsaturated fatty acids (34.41%) in the total lipid of B. semiorbiculata collected in Phu Quoc was higher than that (26.36%) in Nam Du. The content of n-3 and n-6 fatty acids (20:4n-6, 20:5n-3, 22:6n-3) was high in the composition of fatty acids of both mussels.

Bisphenol A Impairs Lipid Remodeling Accompanying Cell Differentiation in the Oligodendroglial Cell Line Oli-Neu.

In the central nervous system, the process of myelination involves oligodendrocytes that wrap myelin around axons. Myelin sheaths are mainly composed of lipids and ensure efficient conduction of action potentials. Oligodendrocyte differentiation is an essential preliminary step to myelination which, in turn, is a key event of neurodevelopment. Bisphenol A (BPA), a ubiquitous endocrine disruptor, is suspected to disrupt this developmental process and may, thus, contribute to several neurodevelopmental disorders. In this study, we assessed the effect of BPA on oligodendrocyte differentiation through a comprehensive analysis of cell lipidome by UHPLC-HRMS. For this purpose, we exposed the oligodendroglial cell line Oli-neu to several BPA concentrations for 72 h of proliferation and another 72 h of differentiation. In unexposed cells, significant changes occurred in lipid distribution during Oli-neu differentiation, including an increase in characteristic myelin lipids, sulfatides, and ethanolamine plasmalogens, and a marked remodeling of phospholipid subclasses and fatty acid contents. Moreover, BPA induced a decrease in sulfatide and phosphatidylinositol plasmalogen contents and modified monounsaturated/polyunsaturated fatty acid relative contents in phospholipids. These effects counteracted the lipid remodeling accompanying differentiation and were confirmed by gene expression changes. Altogether, our results suggest that BPA disrupts lipid remodeling accompanying early oligodendrocyte differentiation.

HDL Structure.

HDL has various protein components, including enzymes, complement components, apolipoproteins, protease inhibitors, etc. In addition to proteins, lipids are also a significant component of HDL. These components and their structure determine the function of HDL. HDL is heavily involved in the acute response phase, complement regulation phase, hemostasis phase, immune response phase, and protease inhibition phase. Among the apolipoproteins, the predominant component is Apo A-I, which confers various atherogenic activities to HDL. Apo A-II, Apo-C, Apo-D, Apo-F, Apo-H, Apo-J, and Apo-O, which can bind free fatty acids, regulate the activity of many proteins involved in HDL metabolism, inhibit lipid transfer, and control the endogenous coagulation cascade. A major functional component is the enzyme LCAT, which helps catalyze the conversion of cholesterol to plasma-based lipoproteins and then to cholesteryl esters. Another enzyme associated with HDL is human paraoxonase, calcium-, PON1-, PON2-, and PON3-dependent lactone enzyme with catalytic activity, including reversible binding to substrates. PAF-AH is a phospholipase with lipoprotein properties, and HDL and LDL particles are commonly bound to plasma PAF-AH for circulation. As for lipid components, PC is an essential phospholipid subclass and may be a biomarker for constitutive inflammation. Sphingolipids, such as sphingomyelin and ceramide, also play an indispensable role in HDL function. In different physiological and pathological stages and plasma environments, HDL can exhibit different structural features, such as discoid HDL and spherical rHDL.

SEASONAL VARIATION OF FATTY ACID COMPOSITION OF PHOSPHOLIPID SUBCLASSES IN MUSCLE TISSUE IN MALE, ALBURNUS MUSSULENSIS

Fatty acids are quite important both as an energy source and in terms of functional tasks for living systems. In addition, these compounds are the structures that have the greatest change depending ecological factors in terms of biochemical. These biochemical compounds are located in the cell structure. So, Analysis of these fatty acids, which have very important membrane integrity and permeability in life, is very important for living things. Therefore, fatty acid analysis at the phospholipid level is quite important. In this study, it was aimed to determine the seasonal variation of the fatty acids of phospholipid subclasses in muscle tissue. In our study, sexes of the samples caught from Batman Dam Lake were determined in the laboratory. After the total lipid extraction of the muscle tissue belonging to the male one was made, it was separated into phospholipid subclasses by thin layer chromatography. After the methylation process, samples were analyzed qualitatively as % fatty acid with Gas Chromatography. As a result of analysis, a total of 16 fatty acids were determined. As a results of analyses, out of saturated fatty acids, 16:0 and 18:0; out of monosaturated ones, 16:1n-7 and 18:1n-9; out of polyunsaturated ones, 20:4n-6, 20:5n-3 22:5n-322:5n-3 and 22:6n-6 were identified as the major fatty acids. When the fatty acid distribution is examined, 16:0 in PC; 18:0 in PI and PS; 18:1n-9 in PC and PS; in 20:4n-6 PI; 20:5n-3 in PC and PI; 22:6n-3 and n-3 in PE and n-6 were found to be higher in PI than others. It is detected that in April, total PUFA and n-3 in PC, PE and PI; in November and January, total SFA in PSs are higher than the other months. In our study, the PI subclasses n-3/n-6 rate of the fish has been at the lowest level according to PC, PE and PS.

Lipid metabolism is a novel and practical source of potential targets for antiviral discovery against porcine parvovirus

How parvovirus manipulates host lipid metabolism to facilitate its propagation, pathogenicity and consequences for disease, is poorly characterized. Here, we addressed this question using porcine parvovirus (PPV) to understand the complex interactions of parvovirus with lipid metabolism networks contributing to the identification of novel and practical antiviral candidates. PPV significantly alters host lipid composition, characteristic of subclasses of phospholipids and sphingolipids, and induces lipid droplets (LDs) formation via regulating calcium-independent PLA2β (iPLA2β), phospholipase Cγ2 (PLCγ2), diacylglycerol kinase α (DKGα), phosphoinositide 3-kinase (PI3K), lysophosphatidic acid acyltransferase θ (LPAATθ), and sphingosine kinases (SphK1 and SphK2). PPV utilizes and exploits these enzymes as well as their metabolites and host factors including MAPKs (p38 and ERK1/2), protein kinase C (PKC) and Ca2+ to induce S phase arrest, apoptosis and incomplete autophagy, all benefit to PPV propagation. PPV also suppresses prostaglandin E2 (PGE2) synthesis via downregulating cyclooxygenase-1 (COX-1), indicating PPV hijacks COX-1-PGE2 axis to evade immune surveillance. Our data support a model where PPV to establishes an optimal environment for its propagation and pathogenicity via co-opting host lipid metabolism, being positioned as a source of potential targets.

A targeted knockdown of Agps in H9c2 cells lowered the level of plasmalogen lipids that disturbed mitochondrial function

Plasmalogens belong to a subclass of phospholipids called ether lipids. The peroxisome synthesize these lipids and involve the limiting AGPS enzyme. In addition, mutations in the Agps gene are associated with cardiac manifestations. We hypothesized that decreased plasmalogens in cells negatively affect mitochondrial function and cell survival. We aimed to evaluate the metabolic and functional consequences of plasmalogens deficiency in a cardiomyoblastic cell line (H9c2 cells) modified using a CRISPR-Cas9 strategy targeting the Agps gene. We characterized this cell line using qPCR and immunoblotting to explore the influence on markers related to mitochondrial function [biogenesis, fatty acid metabolism (FA)], endoplasmic reticulum (ER) stress and apoptosis. AGPS reduction was validated at the gene (−58%) and protein (−78%) level, and is associated with decreased plasmalogens (−76%) that we analysed using mass spectrometry. This deficiency leaded to mitochondrial perturbations as revealed by changes on the expression of genes involved in biogenesis: Pgc-1α and ß (−27%; −61%), dynamics: Opa1 and Mff (−15%) as well as in the use of FA: Cd36 and Cpt1 (−52%; −51%) and in the oxidation of FA: Vlcad and Lcad (−22%; −13%). Consistently, using mass spectrometry, we observed decreased acylcarnitines (̴75%) used as markers of mitochondrial FA metabolism. This is accompanied with signs of increased ER stress and apoptosis as suggested by the increase in Chop gene expression (+31%) and the decreased uncleaved form of the Caspase-3 protein (−32%), respectively. Finally, we were able to normalize the levels of plasmalogen in our cells using alkylglycerols. Collectively, these results demonstrate that lowering plasmalogens affects mitochondrial function and cell stress in H9c2 cells. The normalisation of plasmalogens using alkylglycerols is encouraging to further characterize their metabolic and functional benefits.

Comprehensive Identification of Glycosphingolipids in Human Plasma Using Hydrophilic Interaction Liquid Chromatography-Electrospray Ionization Mass Spectrometry.

Glycosphingolipids (GSL) represent a highly heterogeneous class of lipids with many cellular functions, implicated in a wide spectrum of human diseases. Their isolation, detection, and comprehensive structural analysis is a challenging task due to the structural diversity of GSL molecules. In this work, GSL subclasses are isolated from human plasma using an optimized monophasic ethanol–water solvent system capable to recover a broad range of GSL species. Obtained deproteinized plasma is subsequently purified and concentrated by C18-based solid-phase extraction (SPE). The hydrophilic interaction liquid chromatography coupled to electrospray ionization linear ion trap tandem mass spectrometry (HILIC-ESI-LIT-MS/MS) is used for GSL analysis in the human plasma extract. Our results provide an in-depth profiling and structural characterization of glycosphingolipid and some phospholipid subclasses identified in the human plasma based on their retention times and the interpretation of tandem mass spectra. The structural composition of particular lipid species is readily characterized based on the detailed interpretation of mass spectrometry (MS) and tandem mass spectrometry (MS/MS) spectra and further confirmed by specific fragmentation behavior following predictable patterns, which yields to the unambiguous identification of 154 GSL species within 7 lipid subclasses and 77 phospholipids representing the highest number of GSL species ever reported in the human plasma. The developed HILIC-ESI-MS/MS method can be used for further clinical and biological research of GSL in the human blood or other biological samples.

Deletion of lysophosphatidylcholine acyltransferase 3 in myeloid cells worsens hepatic steatosis after a high-fat diet

Recent studies have highlighted an important role for lysophosphatidylcholine acyltransferase 3 (LPCAT3) in controlling the PUFA composition of cell membranes in the liver and intestine. In these organs, LPCAT3 critically supports cell-membrane-associated processes such as lipid absorption or lipoprotein secretion. However, the role of LPCAT3 in macrophages remains controversial. Here, we investigated LPCAT3's role in macrophages both in vitro and in vivo in mice with atherosclerosis and obesity. To accomplish this, we used the LysMCre strategy to develop a mouse model with conditional Lpcat3 deficiency in myeloid cells (Lpcat3KOMac). We observed that partial Lpcat3 deficiency (approximately 75% reduction) in macrophages alters the PUFA composition of all phospholipid (PL) subclasses, including phosphatidylinositols and phosphatidylserines. A reduced incorporation of C20 PUFAs (mainly arachidonic acid [AA]) into PLs was associated with a redistribution of these FAs toward other cellular lipids such as cholesteryl esters. Lpcat3 deficiency had no obvious impact on macrophage inflammatory response or endoplasmic reticulum (ER) stress; however, Lpcat3KOMac macrophages exhibited a reduction in cholesterol efflux in vitro. In vivo, myeloid Lpcat3 deficiency did not affect atherosclerosis development in LDL receptor deficient mouse (Ldlr−/−) mice. Lpcat3KOMac mice on a high-fat diet displayed a mild increase in hepatic steatosis associated with alterations in several liver metabolic pathways and in liver eicosanoid composition. We conclude that alterations in AA metabolism along with myeloid Lpcat3 deficiency may secondarily affect AA homeostasis in the whole liver, leading to metabolic disorders and triglyceride accumulation.

The Changes in Composition of Phospholipid Subclasses Fatty Acids Prepared from Prediapausing and Postdiapausing Adults of Sunn Pest, Eurygaster integriceps Put. (Heteroptera: Scutelleridae)

Bu çalışmada, süne, Eurygaster integriceps’in diyapoz öncesi ergin ve diyapoz sonrası erginlerinin fosfatidilkolin (PC), fosfatidiletanolamin (PE), fosfatidilinositol (PI) ve fosfatidilserin (PS) gibi fosfolipit (PL) altsınıflarının yağ asidi kompozisyonundaki değişiklikler araştırılmıştır. Fosfolipit alt sınıflarının ayrılmasında İnce Tabaka Kromatoğrafisi tekniği, yağ asitlerinin analizinde ise Gaz kromatoğrafi cihazı kullanılmıştır. Eurygaster integriceps’in PL altsınıflarında gözlenen dominant yağ asitleri, doymuş yağ asitlerinden (SFA) palmitik asit (16:0), tekli doymamış yağ asitlerinden (MUFA) oleik asit (18:1n-9) ve çoklu doymamış yağ asitlerinden (PUFA) linoleik asit (18:2n-6) idi. Diyapoz öncesi ve diyapoz sonrası erginlerin PC, PE ve PS fraksiyonlarının yağ asidi içeriğindeki değişikliklerin benzer olduğu bulunmuştur. Diyapoz sonrası erginlerin bu fraksiyonlarında 16:0, 18:0 ve ∑SFA yüzdeleri diyapoz öncesi erginlere oranla daha düşük; ancak16:1n-7, ∑MUFA, 18:2n-6 ve ∑PUFA ise daha yüksek olarak bulunmuştur. Sünenin diyapoz sonrası bireylerin PE ve PC fraksiyonlarındaki 18:1n-9 düzeyi, diyapoz öncesi bireylerden önemli derecede daha yüksek olarak tespit edilmiştir. Diyapoz sonrası erginlerin tüm PL altsınıflarındaki doymamış yağ asitlerinin doymuş yağ asitlere oranı (UFA/SFA), diyapoz öncesi erginlerden daha yüksek bulunmuştur.

Surfactant Injury in the Early Phase of Severe Meconium Aspiration Syndrome.

No in vivo data are available regarding the effect of meconium on human surfactant in the early stages of severe meconium aspiration syndrome (MAS). In the present study, we sought to characterize the changes in surfactant composition, function, and structure during the early phase of meconium injury. We designed a translational prospective cohort study of nonbronchoscopic BAL of neonates with severe MAS (n = 14) or no lung disease (n = 18). Surfactant lipids were analyzed by liquid chromatography-high-resolution mass spectrometry. Secretory phospholipase A2 subtypes IB, V, and X and SP-A (surfactant protein A) were assayed by ELISA. SP-B and SP-C were analyzed by Western blotting under both nonreducing and reducing conditions. Surfactant function was assessed by adsorption test and captive bubble surfactometry, and lung aeration was evaluated by semiquantitative lung ultrasound. Surfactant nanostructure was studied using cryo-EM and atomic force microscopy. Several changes in phospholipid subclasses were detected during MAS. Lysophosphatidylcholine species released by phospholipase A2 hydrolysis were increased. SP-B and SP-C were significantly increased together with some shorter immature forms of SP-B. Surfactant function was impaired and correlated with poor lung aeration. Surfactant nanostructure was significantly damaged in terms of vesicle size, tridimensional complexity, and compactness. Various alterations of surfactant phospholipids and proteins were detected in the early phase of severe meconium aspiration and were due to hydrolysis and inflammation and a defensive response. This impairs both surfactant structure and function, finally resulting in reduced lung aeration. These findings support the development of new surfactant protection and antiinflammatory strategies for severe MAS.

Characterization of lipid composition in the muscle tissue of four shrimp species commonly consumed in China by UPLC−Triple TOF−MS/MS

In this study, comprehensive lipid composition in the muscle tissue of four popularly consumed shrimp species was determined using ultra-performance liquid chromatography-triple time-of-flight tandem mass spectrometry (UPLC−Triple TOF−MS/MS). About 600 molecules from 14 types of lipids were characterized and quantified. Phospholipids (PLs) were the main component in all four shrimp species (51.4–71.0% of total lipids). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were the major PL subclasses (49.3–53.2% and 42.3–48.4% of total PLs). Triacylglycerol (TAG) and diacylglycerol (DAG) contents were relatively low (8.6–32.5% and 11.5–14.1% of total lipids). Docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (AA, 20:4n-6) were dominant in free fatty acids (76.5–85.2%) and PL. Sphingolipid (SL) was detected in low content (<5% of total lipids). Using high throughput analytical method, detailed lipid composition in shrimp muscle were obtained, which could help to assess shrimp nutrition value and identify their species.