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Codium fragile (Suringar) Hariot, the green seaweed species belonging to the family Codiaceae, is one of the mass macrophyte species in the Pacific Region of the Russian Federation. The C. fragile total lipid content amounts 13.92 ± 0.22 mg per g of dry tissue, of which 44% are glycolipids, 40% come from neutral lipids, while phospholipids account for 16%. The content of polyunsaturated fatty acids (PUFAs) in C. fragile lipid extract is over 50% of the total fatty acids, of which ω-3 (36.2%) and ω-6 (17.8%) are predominant. Here, we studied the effects of the C. fragile lipid extract and Omega-3 reference drug on biochemical and physiological parameters of erythrocytes in mice exposed to stress (vertical fixation by the scruff skinfold). Under the impact of stress, erythrocytes underwent alterations in both their dimensional characteristics and membrane phospholipid profiles, leading to changes in their permeability and lability, as well as impeding their circulation through the capillary bed. The endogenous antioxidant defense system in stress-exposed mice experienced a considerable strain, as evidenced by an increase in the malonic dialdehyde level, with a simultaneous decrease in plasma superoxide dismutase and antiradical activities. The administration of the C. fragile lipid extract to stress-exposed mice entailed the restoration of the erythrocyte membrane lipid content, a decrease in the amount of lysophospholipids, and the normalization of the sphingomyelin/phosphatidylcholine ratio, which contributed to the recovery of erythrocyte dimensional characteristics and osmotic resistance, as well as blood antioxidant system parameters. The pronounced stress- and membrane-protective effect of the C. fragile lipid extract was due to the presence in its composition of a wide range of neutral and polar lipids containing ω-3 and ω-6 PUFAs, which ensured a higher anti-stress efficacy of the algal extract compared to the Omega-3 reference preparation. [ABSTRACT FROM AUTHOR]

Lipids of air-dried leaves of the hemi-halophyte plant Limonium gmelinii (Willd.) Kuntze (Plumbaginaceae) growing on the dry bed of the Aral Sea were studied. The leaves contained neutral lipids (NL, 0.84% of the mass), glycolipids (GL, 1.78), and phospholipids (PhL, 0.74). The compositions of the lipophilic constituents of the NL and hydrocarbons were determined. Fatty acids of NL were dominated by 18:2n6 (53.45%); of GL and PhL, 16:0 (40.14 and 53.98%, respectively). The lipophilic constituents exhibited weak antifungal and high growth-stimulating and stress-protective activity under salt stress conditions. [ABSTRACT FROM AUTHOR]

Pulmonary surfactant, which is a complex mixture of lipids and proteins, plays a key role in the functional properties of the respiratory system. Lipids form complexes with proteins to maintain low values of surface tension at continuous compression/expansion deformations. However, interactions that lead to the complexation still remain to be unknown thus significantly hampering the development of synthetic analogs of the natural pulmonary surfactant. In this work, the methods of surface rheology and ellipsometry have been employed to study the dynamic properties of model phospholipid monolayers applied onto the surfaces of synthetic polyelectrolyte solutions. It has been shown, that electrostatic or hydrophobic interactions between lipids and macromolecules are insufficient for the efficient complexation and maintenance of low surface tension values. [ABSTRACT FROM AUTHOR]

For the first time the qualitative and quantitative lipid profile (total lipids and polar and nonpolar lipids) of the muscle tissue of six mesopelagic fish species, which are representatives of two deep-sea families widespread in the World Ocean: Stomiidae and Myctophidae were studied. It was found the species specificity of lipid accumulation for the studied fishes, which indicates differences in the mechanisms of compensatory responses. Triacylglycerols are the main form of lipid storage in the studied species. However, an accumulation of cholesterol esters and waxes (lipid characteristic of vertical migrants) has also been recorded in Borostomias antarcticus. The revealed distinctive features of Myctophidae and Stomiatidae, related to the accumulation of cholesterol and variations in the content of different phospholipid fractions, indicate that the fishes of these families use different mechanisms for regulating and maintaining the physicochemical state (permeability and fluidity) of biological membranes under conditions of change in a set of environmental factors (temperature, salinity, hydrostatic pressure, and specific photoperiod) with increase in the habitat depth. [ABSTRACT FROM AUTHOR]

Background: Bees provide essential pollination services for many food crops and are critical in supporting wild plant diversity. However, the dietary landscape of pollen food sources for social and solitary bees has changed because of agricultural intensification and habitat loss. For this reason, understanding the basic nutrient metabolism and meeting the nutritional needs of bees is becoming an urgent requirement for agriculture and conservation. We know that pollen is the principal source of dietary fat and sterols for pollinators, but a precise understanding of what the essential nutrients are and how much is needed is not yet clear. Sterols are key for producing the hormones that control development and may be present in cell membranes, where fatty-acid-containing species are important structural and signalling molecules (phospholipids) or to supply, store and distribute energy (glycerides). Aim of the review: In this critical review, we examine the current general understanding of sterol and lipid metabolism of social and solitary bees from a variety of literature sources and discuss implications for bee health. Key scientific concepts of review: We found that while eusocial bees are resilient to some dietary variation in sterol supply the scope for this is limited. The evidence of both de novo lipogenesis and a dietary need for particular fatty acids (FAs) shows that FA metabolism in insects is analogous to mammals but with distinct features. Bees rely on their dietary intake for essential sterols and lipids in a way that is dependent upon pollen availability. [ABSTRACT FROM AUTHOR]

Tandem pore domain (K2P) potassium channels modulate resting membrane potentials and shape cellular excitability. For the mechanosensitive subfamily of K2Ps, the composition of phospholipids within the bilayer strongly influences channel activity. To examine the molecular details of K2P lipid modulation, we solved cryo-EM structures of the TREK1 K2P channel bound to either the anionic lipid phosphatidic acid (PA) or the zwitterionic lipid phosphatidylethanolamine (PE). At the extracellular face of TREK1, a PA lipid inserts its hydrocarbon tail into a pocket behind the selectivity filter, causing a structural rearrangement that recapitulates mutations and pharmacology known to activate TREK1. At the cytoplasmic face, PA and PE lipids compete to modulate the conformation of the TREK1 TM4 gating helix. Our findings demonstrate two distinct pathways by which anionic lipids enhance TREK1 activity and provide a framework for a model that integrates lipid gating with the effects of other mechanosensitive K2P modulators. Tandem pore (K2P) potassium channels set the cellular resting membrane potential in tissues throughout the body. Here, authors show how the composition of phospholipid within the bilayer may directly alter gating in this family of ion channels. [ABSTRACT FROM AUTHOR]

The composition of lipids isolated from the middle leaves and juice of 7-year-old Aloe arborescens Mill. and the inhibitory efficiency of lipids from the leaves of this aloe species were studied. The phospholipid fractions were divided by means of TLC method. The quantitative ratio of phospholipid fractions was analyzed spectrophotometrically. The most essential differences in the composition of phospholipids (PL) from aloe leaves and juice were revealed for the ratio of the more poorly oxidizable fractions. The more low relative content of PL in the total lipid composition from aloe leaves compared with than in lipids from juice result in 16% diminution in the molar ratio [sterols]/[PL] in the composition of lipids from aloe juice because shares of sterols are the same in lipids from aloe leaves and juice. Lipids from aloe leaves are shown to characterize the high inhibitory efficiency that is demonstrated by model of the low temperature methyl oleate autoxidation in a thin layer. Using UV spectroscopy and the mathematic processing of UV spectra by Gauss method the presence of biologically active substances contained in lipids was analyzed. There are only flavonoids in the chloroform solution of lipids from aloe juice, while in lipids from aloe leaves, in addition to flavonoids, carotenoids is also found at a low quantity. [ABSTRACT FROM AUTHOR]

TMEM16F is a Ca2+-activated phospholipid scramblase in the TMEM16 family of membrane proteins. Unlike other TMEM16s exhibiting a membrane-exposed hydrophilic groove that serves as a translocation pathway for lipids, the experimentally determined structures of TMEM16F shows the groove in a closed conformation even under conditions of maximal scramblase activity. It is currently unknown if/how TMEM16F groove can open for lipid scrambling. Here we describe the analysis of ~400 µs all-atom molecular dynamics (MD) simulations of the TMEM16F revealing an allosteric mechanism leading to an open-groove, lipid scrambling competent state of the protein. The groove opens into a continuous hydrophilic conduit that is highly similar in structure to that seen in other activated scramblases. The allosteric pathway connects this opening to an observed destabilization of the Ca2+ ion bound at the distal site near the dimer interface, to the dynamics of specific protein regions that produces the open-groove state to scramble phospholipids. Molecular dynamics simulations reveal the allosteric mechanism leading to an open, lipid scrambling competent state of a mammalian TMEM16F. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum (ER)-mitochondria contact site (ERMCS) is crucial for exchanging biological molecules such as phospholipids and Ca2+ ions between these organelles. Mitoguardin-2 (MIGA2), a mitochondrial outer membrane protein, forms the ERMCS in higher eukaryotic cells. Here, we report the crystal structures of the MIGA2 Lipid Droplet (LD) targeting domain and the ER membrane protein VAPB bound to the phosphorylated FFAT motif of MIGA2. These structures reveal that the MIGA2 LD targeting domain has a large internal hydrophobic pocket that accommodates phospholipids and that two phosphorylations of the FFAT motif are required for tight interaction of MIGA2 with VAPB, which enhances the rate of lipid transport. Further biochemical studies show that MIGA2 transports phospholipids between membranes with a strong preference for binding and trafficking phosphatidylserine (PS). These results provide a structural and molecular basis for understanding how MIGA2 mediates the formation of ERMCS and facilitates lipid trafficking at the ERMCS. The ER-mitochondria contact sites are crucial for exchanging phospholipids. Here, Kim et al. present crystal structures of mitoguardin-2 (MIGA2) which reveal that MIGA2 directly binds phospholipids and transfers them between the ER and mitochondria. [ABSTRACT FROM AUTHOR]

Metal ion-membrane interactions have gained appreciable attention over the years resulting in increasing investigations into the mode of action of toxic and essential metals. More work has focused on essential ions like Ca or Mg and toxic metals like Cd and Pb, whereas this study investigates the effects of the abundant essential trace metal manganese with model lipid systems by screening zwitterionic and anionic glycerophospholipids. Despite its essentiality, deleterious impact towards cell survival is known under Mn stress. The fluorescent dyes Laurdan and diphenylhexatriene were used to assess changes in membrane fluidity both in the head group and hydrophobic core region of the membrane, respectively. Mn-rigidified membranes composed of the anionic phospholipids, phosphatidic acid, phosphatidylglycerol, cardiolipin, and phosphatidylserine. Strong binding resulted in large shifts of the phase transition temperature. The increase was in the order phosphatidylserine > phosphatidylglycerol > cardiolipin, and in all cases, saturated analogues > mono-unsaturated forms. Dynamic light scattering measurements revealed that Mn caused extensive aggregation of liposomes composed of saturated analogues of phosphatidic acid and phosphatidylserine, whilst the mono-unsaturated analogue had significant membrane swelling. Increased membrane rigidity may interfere with permeability of ions and small molecules, possibly disrupting cellular homeostasis. Moreover, liposome size changes could indicate fusion, which could also be detrimental to cellular transport. Overall, this study provided further understanding into the effects of Mn with biomembranes, whereby the altered membrane properties are consequential to the proper structural and signalling functions of membrane lipids. [ABSTRACT FROM AUTHOR]

Ceramides and phosphatidylcholines (PCs) are bioactive lipids and lipid bilayer membrane components. Distinct ceramides/PCs (ratios) predict cardiovascular outcome in patients with coronary artery disease. Extracellular vesicles (EVs) are proposed biomarkers for cardiovascular disease and contain ceramides/PCs. Ceramides/PCs have not been studied in patients undergoing carotid endarterectomy (CEA) nor in EVs. We therefore investigated whether levels of ceramides/PCs in plasma and EVs are associated with postoperative risk of major adverse cardiovascular events (MACE) following CEA. In 873 patients undergoing CEA of the Athero-Express biobank, we quantitatively measured seven ceramides/PCs in preoperative blood samples: Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0), Cer(d18:1/24:1), PC(14:0/22:6), PC(16:0/16:0) and PC(16:0/22:5) in plasma and two plasma EV-subfractions (LDL and TEX). We analyzed the association of ceramides, PCs and their predefined ratios with the three-year postoperative risk of MACE (including stroke, myocardial infarction and cardiovascular death). A total of 138 patients (16%) developed MACE during the three-year follow-up. In the LDL-EV subfraction, higher levels of Cer(d18:1/24:1) and Cer(d18:1/16:0)/PC(16:0/22:5) ratio were significantly associated with an increased risk of MACE (adjusted HR per SD [95% CI] 1.24 [1.01–1.53] and 1.26 [1.04–1.52], respectively). In the TEX-EV subfraction, three ratios Cer(d18:1/16:0)/Cer(d18:1/24:0), Cer(d18:1/18:0)/Cer(d18:1/24:0) and Cer(d18:1/24:1)/Cer(d18:1/24:0) were positively associated with MACE (adjusted HR per SD 1.34 [1.06–1.70], 1.24 [1.01–1.51] and 1.31 [1.08–1.58], respectively). In conclusion, distinct ceramides and PCs in plasma EVs determined in preoperative blood were independently associated with an increased 3-year risk of MACE after CEA. These lipids are therefore potential markers to identify high-risk CEA patients qualifying for secondary preventive add-on therapy. [ABSTRACT FROM AUTHOR]

Membrane lipid remodeling contributes to the environmental acclimation of plants. In the green lineage, a betaine lipid, diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), is included exclusively among green algae and nonflowering plants. Here, we show that the green alga Chlorella kessleri synthesizes DGTS under phosphorus-deficient conditions through the eukaryotic pathway via the ER. Simultaneously, phosphatidylcholine and phosphatidylethanolamine, which are similar to DGTS in their zwitterionic properties, are almost completely degraded to release 18.1% cellular phosphorus, and to provide diacylglycerol moieties for a part of DGTS synthesis. This lipid remodeling system that substitutes DGTS for extrachloroplast phospholipids to lower the P-quota operates through the expression induction of the BTA1 gene. Investigation of this lipid remodeling system is necessary in a wide range of lower green plants for a comprehensive understanding of their phosphorus deficiency acclimation strategies. Oishi et al. report that the synthesis of a betaine lipid, diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) in a green alga Chlorella kessleri replaces phosphatidylcholine and phosphatidylethanolamine, the two most abundant phospholipids, during phosphate deprivation. This study provides insights into the understanding of the phosphorus-deficiency acclimation strategies via lipid remodeling in lower green plants. [ABSTRACT FROM AUTHOR]

A comparative study of lipid profile of the daubed shanny Leptoclinus maculatus postlarvae from fjords of different domains (arctic-boreal Kongsfjord and high-arctic Rjipfjord) of Svalbard Archipelago waters in summer was performed. A more efficient accumulation of lipids in the fishes from Kongsfjord compared to Rjipfjord due to triacylglycerols and wax esters was established. These differences may be related mainly to the trophic conditions of the habitat (species composition, abundance, and availability of food items). The higher level of cholesterol esters than wax esters at the L1 stage of development of the daubed shanny postlarvae compared to older fishes pointed to their active feeding mainly on phytoplankton. The differences in the content of certain classes of phospholipids may indicate adaptive changes at the level of biomembranes, contributing to the maintenance of cell homeostasis in response to abiotic environmental factors, and reflect their additional intake with food at the early stages of fish development. [ABSTRACT FROM AUTHOR]

A Gram-stain-positive, aerobic, nonmotile actinobacterium, designated strain YIM 93776T, was isolated from a saline sediment sample collected from Aiding Lake in Xinjiang Uygur Autonomous Region, Northwest China. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain YIM 93776T was affiliated to the genus Glycomyces and was closely related to Glycomyces albus TRM 49136T (97.6% sequence similarity), Glycomyces lacisalsi XHU 5089T (97.0%) and Glycomyces anabasis EGI 6500139T (96.2%). The cell wall contained meso-diaminopimelic acid and the whole-cell hydrolysates sugars were galactose, mannose, arabinase, glucose and ribose. The predominant menaquinones were MK-9 (H4) and MK-10 (H4). Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two phosphatidylglyceride, two unidentified phospholipids and two unidentified polar lipids were detected in the polar lipid extracts. Major fatty acids were anteiso-C17:0, iso-C15:0, iso-C16:0, anteiso-C15:0 and anteiso C17:1 A. The draft genome sequence of strain YIM 93776T was 5.37 Mbp in size with 69.5% DNA G + C content. The dDDH and ANI values between strain YIM 93776T and related neighbours were 25.0–34.3% and 77.3–79.8%, respectively. On the basis of morphological, chemotaxonomic and phylogenetic evidence, strain YIM 93776T; therefore, represents a novel species, for which the name Glycomyces salinus sp. nov. is proposed. The type strain is YIM 93776T (= KCTC 49430T = CGMCC 4.7685T). [ABSTRACT FROM AUTHOR]

Background: While no "gold-standard" pharmacotherapy for nonalcoholic fatty liver disease (NAFLD) is yet established, essential phospholipids (EPLs) are reported to decrease steatosis and improve laboratory parameters. Objective: This analysis evaluated adherence and satisfaction with EPL treatment as patient-reported outcomes and their relationship with changes in laboratory and ultrasound parameters among Russian patients with NAFLD. Methods: Data were pooled from three observational Russian studies—MANPOWER (2015–2016), LIDER 1 (2012–2013), and LIDER 2 (2013)—in which EPLs were used for at least 12 weeks in the treatment of liver diseases and which measured both subjective and objective endpoints. Only patients who had NAFLD were included in this analysis. The main endpoints were to determine treatment adherence and satisfaction with 12 weeks of EPL therapy, relationship between adherence/satisfaction and changes in the laboratory and ultrasound parameters. A secondary subgroup analysis was performed to identify patients with NAFLD who responded better (or worse) to 24 weeks of adjunctive EPL treatment. Results: Overall, 3384 patients were included. A total of 82.2% of patients were adherent to 12 weeks of EPL treatment; high/very high satisfaction was reported by 15.3%/65.9% of clinicians and 15.9%/64.4% of patients. There was positive correlation between patients' adherence and satisfaction and significant improvement in laboratory (transaminases, lipid profile; p < 0.001) and ultrasound (steatosis, p < 0.001) parameters, and improvement in symptoms (p < 0.001) after 24 weeks of EPL. Male patients, patients with unhealthy lifestyles, and those with more comorbidities showed a better response in laboratory and ultrasound parameters. Conclusions: Patients with NAFLD treated with adjunctive EPL therapy in real-world clinical practice in Russia showed good treatment adherence and treatment satisfaction. Improvements in laboratory and ultrasound parameters, as well as dynamics of patient symptoms, were positively correlated with adherence and satisfaction. Plain Language Summary: Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver disease, and patients have a risk of liver cancer and needing transplantation. Patients with advanced NAFLD are usually recommended to use medication. Clinical trials in patients with NAFLD showed that essential phospholipids (EPLs) comprising phosphatidylcholine improved liver fat accumulation (known as steatosis), so treatment guidelines in several countries recommend they be added to the usual therapy. EPLs have been associated with both objective and subjective improvements. This real-world study evaluated three observational studies to assess how patient adherence and satisfaction with EPL treatment were related to changes in clinical parameters in 3384 Russian patients with NAFLD. Overall, 82.2% of patients were adherent with 12 weeks of EPL therapy, and almost two-thirds of patients (64.4%) and clinicians (65.9%) reported very high satisfaction with treatment. Patients' adherence and satisfaction increased alongside significant improvements in liver enzymes, lipid levels, liver fat content (steatosis), and fewer symptoms after 24 weeks of EPL therapy. Male patients, those with an unhealthy lifestyle, and those with other comorbid conditions had the best response to EPL therapy. This study shows that Russian patients with NAFLD have good adherence and satisfaction with EPL therapy in routine clinical practice and highlights the importance of adherence to EPL therapy in these patients. [ABSTRACT FROM AUTHOR]

Cells can expand their plasma membrane laterally by unfolding membrane undulations and by exocytosis. Here, we describe a third mechanism involving invaginations held shut by the membrane adapter, dynamin. Compartments open when Ca activates the lipid scramblase, TMEM16F, anionic phospholipids escape from the cytoplasmic monolayer in exchange for neutral lipids, and dynamins relax. Deletion of TMEM16F or dynamins blocks expansion, with loss of dynamin expression generating a maximally expanded basal plasma membrane state. Re-expression of dynamin2 or its GTPase-inactivated mutant, but not a lipid binding mutant, regenerates reserve compartments and rescues expansion. Dynamin2-GFP fusion proteins form punctae that rapidly dissipate from these compartments during TMEM16F activation. Newly exposed compartments extend deeply into the cytoplasm, lack numerous organellar markers, and remain closure-competent for many seconds. Without Ca, compartments open slowly when dynamins are sequestered by cytoplasmic dynamin antibodies or when scrambling is mimicked by neutralizing anionic phospholipids and supplementing neutral lipids. Activation of Ca-permeable mechanosensitive channels via cell swelling or channel agonists opens the compartments in parallel with phospholipid scrambling. Thus, dynamins and TMEM16F control large plasma membrane reserves that open in response to lateral membrane stress and Ca influx. Cells locally expand and retract their surface in response to environmental factors such as changes in membrane tension. Here the authors show the membrane adapter, dynamin2, locally constricts surface membrane to form an isolated but contiguous membrane reservoir that can open upon phospholipid scrambling via TMEM16F. [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, non-motile, aerobic, rod-shaped and reddish-pigmented bacterium, designated 8A47T, was isolated from a marine solar saltern located in Wendeng, PR China. The novel strain 8A47T grows at 20–42 °C, pH 7.0–9.0, and in the presence of 2.0–14.0% (w/v) NaCl. Optimal growth was observed at 37–40 °C, pH 7.5–8.0, and with 4.0–6.0% (w/v) NaCl. The phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 8A47T formed an evolutionary lineage with members of the genus Rhodohalobacter. Strain 8A47T exhibited high level of similarity to Rhodohalobacter barlenses MCCC 1K03442T (94.7%) and Rhodohalobacter halophilus JZ3C29T (93.5%). The major fatty acids were summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16:0 and iso-C15:0. The sole respiratory quinone was MK-7. The polar lipids of the new isolate consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified lipid, two unidentified phospholipids and three unidentified glycolipids and. The genomic DNA G + C content of the strain 8A47T was 47.7 mol%. Based on its phenotypic, chemotaxonomic, genotypic and genomic characteristics presented in this study, strain 8A47T is considered to represent a novel species of the genus Rhodohalobacter, for which the name Rhodohalobacter mucosus sp. nov. is proposed. The type strain is 8A47T (= KCTC 62603T = MCCC 1H00329T). [ABSTRACT FROM AUTHOR]

The constituent and fatty-acid compositions of neutral lipids (NL), glyco-, and phospholipids and the squalene contents in seeds and the aerial part of Amaranthus retroflexus were studied for the first time. Elaidic acid was observed in all lipid groups. The squalene content was 4.3% of the NL mass in seeds and 3.15% in the aerial part. Preliminary wetting of wheat and cucumber seeds in unsaponified substances, fatty acids, and their methyl esters obtained from A. retroflexus seeds at concentrations 0.001 and 0.0001% was found to reduce the inhibiting action of salt stress. Neutral lipids did not exhibit a protective effect. [ABSTRACT FROM AUTHOR]

Here, we identify iPLA2β as a critical regulator for p53-driven ferroptosis upon reactive oxygen species (ROS)-induced stress. The calcium-independent phospholipase iPLA2β is known to cleave acyl tails from the glycerol backbone of lipids and release oxidized fatty acids from phospholipids. We found that iPLA2β-mediated detoxification of peroxidized lipids is sufficient to suppress p53-driven ferroptosis upon ROS-induced stress, even in GPX4-null cells. Moreover, iPLA2β is overexpressed in human cancers; inhibition of endogenous iPLA2β sensitizes tumor cells to p53-driven ferroptosis and promotes p53-dependent tumor suppression in xenograft mouse models. These results demonstrate that iPLA2β acts as a major ferroptosis repressor in a GPX4-independent manner. Notably, unlike GPX4, loss of iPLA2β has no obvious effect on normal development or cell viability in normal tissues but iPLA2β plays an essential role in regulating ferroptosis upon ROS-induced stress. Thus, our study suggests that iPLA2β is a promising therapeutic target for activating ferroptosis-mediated tumor suppression without serious toxicity concerns. p53 is able to induce ferroptosis in response to reactive oxygen species (ROS)-induced stress and suppresses tumour growth. Here, the authors show that iPLA2β suppresses p53-medated ferroptosis by cleaving and detoxifying peroxidized lipids and that this is independent of canonical ferroptosis regulator GPX4. [ABSTRACT FROM AUTHOR]

Lipids from seeds, leaves, and roots of Primula capitellata Boiss. (Primulaceae) were studied for the first time. The composition of volatile compounds and the fatty-acid composition of neutral lipids, glycolipids, and phospholipids from leaves were established. γ-Linolenic and stearidonic acids and oleic acid methyl ester were identified. [ABSTRACT FROM AUTHOR]

The content and composition of neutral lipids (NL), glycolipids (GL), phospholipids (PhL), and fatty acids (FA) from Chenopodium album seeds are established for the first time. NL contained 15 identified FA; PhL, 16; and GL, 19 constituents including trans-18:1n9. The stress-protective effects of NL, FA, methyl esters of FA, and unsaponifiable substances (US) on the growth and development of wheat and cotton sprouts were studied under salt stress conditions. NL at a concentration of 0.001% and US and FA at a concentration of 0.01% had the greatest effects on the growth of wheat roots. US at a concentration of 0.001% stimulated growth of roots and stems of cotton sprouts; FA, only growth of roots at a concentration of 0.0001%. [ABSTRACT FROM AUTHOR]

Yeast cells adapt to alkaline conditions by activating the Rim101 alkali-responsive pathway. Rim21 acts as a sensor in the Rim101 pathway and detects extracellular alkalization. Interestingly, Rim21 is also known to be activated by alterations involving the lipid asymmetry of the plasma membrane. In this study, we briefly summarize the mechanism of activation and the signal transduction cascade of the Rim101 pathway and propose a hypothesis on how Rim21 is able to detect distinct signals, particularly external alkalization, and altered lipid asymmetry. We found that external alkalization can suppress transbilayer movements of phospholipids between the two leaflets of the plasma membrane, which may lead to the disturbance of the lipid asymmetry of the plasma membrane. Therefore, we propose that external alteration is at least partly sensed by Rim21 through alterations in lipid asymmetry. Understanding this activation mechanism could greatly contribute to drug development against fungal infections. [ABSTRACT FROM AUTHOR]

New data on the effect of additional lighting on the lipid profile of Atlantic salmon 0+ fingerlings during growth and development under artificial cultivation in fish farming conditions were obtained. The influence of different lighting modes, such as standard farming lighting conditions (control), experimental modes of 16 h of light and 8 h of dark (16 : 8), and constant lighting (24 : 0), were studied. Specific modifications of the lipid profile—mainly in the content of structural lipids (phospholipids) as well as indexes of the ratios of structural and reserve lipids: the cholesterol/phospholipids (Chol/PL) and triacylglycerols/phospholipids (TAG/PL)—were found in the fingerlings whose development took place under the conditions of experimental photoperiod regimes. These changes were more pronounced in young salmons cultivated under round-the-clock lighting (24 : 0). [ABSTRACT FROM AUTHOR]

Purpose: Non-lamellar liquid crystal (NLLC)-forming lipids have gained attention as a novel component because of their ability to self-assemble upon contact with body fluids. In this study, a novel NLLC-forming lipid, mono-O-(5, 9, 13-trimethyl-4-tetradecenyl) glycerol ester (C17MGE), and a model drug with a middle molecule weight, leuprolide acetate (LA), were used to confirm the usefulness of C17MGE as an excipient for depot formulations with sustained release properties. Methods: A self-constructed depot formulation was prepared by mixing C17MGE and different types of phospholipids. The constructed NLLC structure was evaluated using small angle X-ray analysis and cryo-transmission electron microscopy. In vitro release and blood concentration profiles of LA were investigated. Results: The NLLC structure was confirmed by small angle X-ray analysis. LA release was able to be modified by adding different ratios of various phospholipids to C17MGE. Formulations containing 1, 2-dioleoyl-sn-glycero-3-phosphoglycerol sodium salt with a mixing ratio of 12% or 24% (MDOPG12 or MDOPG24, respectively) exhibited sustained release profiles of LA. In addition, the blood concentration of LA was detected over 21 days or more after administration of MDOPG12, and the absolute bioavailability was calculated to be about 100%. Conclusions: A depot formulation using C17MGE was useful to achieve sustained release of LA. [ABSTRACT FROM AUTHOR]

Neutral lipids and phospholipids from flowers of Juglans regia were investigated. The contents of saturated and unsaturated fatty acids in the lipids were 34.98 and 65.01%, respectively. Analysis of phospholipids by LC-MS detected six types of phospholipids. Antimicrobial activity of the lipids and phospholipids against bacterial cells of E. coli, C. albicans, and B. subtilis was found. The ac tivity of total phospholipids was greater than that of neutral lipids. The IC50 values for total phospholipids against DPPH, OH, and ABTS were less by 9, 20, and 4 times, respectively. [ABSTRACT FROM AUTHOR]

Lipids and essential oil from roots of licorice (Glycyrrhiza glabra L., Fabaceae) growing in Uzbekistan were investigated. Neutral, glyco-, and phospholipids and lipid-like constituents transferring into benzine (free lipids), CHCl3, and EtOH extracts were identified using CC, TLC, GC, and GC-MS. Total lipids from the roots were dominated (31.8%) by free fatty acids with high contents of linoleic, oleic, and palmitic acids (40.0, 22.7, and 18.3%, respectively). The major constituent of essential oil extracted by steam distillation was carvone (65.3%). [ABSTRACT FROM AUTHOR]

The objective of the present study was to prepare valencene (sesquiterpene) containing invasomes for itraconazole (ITZ) transungual delivery using central composite design. The phospholipid (X1) and valencene (X2) were selected as an independent variables, while vesicles size (Y1), entrapment efficiency (Y2) and in vitro drug release (Y3) were chosen as dependent variables. The antifungal activity of optimized formulation was screened against Trichophyton rubrum, a common causative onychomycosis pathogen, by cup plate method. The optimized ITZ-loaded invasomes formulation presented vesicles size of 176.8 ± 6.03 nm, entrapment efficiency of 83.21 ± 4.11% and in vitro drug release of 75.22 ± 5.03%. The ITZ-loaded invasomes gel formulation showed good homogeneity, pH 6.5 ± 0.23, viscosity 7.33 ± 0.67 Pa s and drug content 94.13 ± 1.13%. The spreadability and extrudability of developed ITZ-loaded invasomes gel were found to be 7.85 ± 0.24 gcm/s and 162 ± 2.74 g, respectively. The ITZ-loaded invasomes gel presented 71.11 ± 3.65% cumulative permeation of drug via goat hooves. The in vitro antifungal activity depicted that the ITZ-loaded invasomes gel and marketed preparation were presented zone of inhibition of 21.42 mm and 10.64 mm against T. rubrum respectively. Hence the prepared ITZ-loaded invasomes formulation could therefore be a promising topical dosage to mitigate the indications and hasten the cure for onychomycosis than conventional available therapies. [ABSTRACT FROM AUTHOR]

Among the living organisms, microscopic fungi are unique in their ability to occupy diverse ecological niches due to the evolutionarily formed mechanisms of adaptation to a broad range of climatic and technogenic factors. One approach to understanding the mechanisms of adaptation to changing environmental conditions is associated with lipid metabolism. The review provides a critical analysis of publications and our own experimental data on the variability of micromycete lipids under the influence of stress factors and of the possible related adaptive mechanisms. The functional, structural, and quantitative changes in fungal lipids were analyzed under the conditions of osmotic, thermal, and cold influences, as well as toxicity. Biochemical variations in the composition of phospholipids and other membrane lipids are characterized as diverse and ambiguous, depending on the degree of exposure, the initial lipid composition, genetic resistance of fungi, and their ability to adapt to extreme conditions. The role of lipid metabolism in the overall integral response of fungal cells to stress is discussed. [ABSTRACT FROM AUTHOR]

Biological membranes, especially the plasma membrane, are considered to be the most sensitive to altered gravity in regard to their properties and functions. We studied the composition and content of lipids, fatty acids and sterols in the plasma membrane fractions isolated from epicotyls and roots of Pisum sativum seedlings grown during 7 days under simulated microgravity by slow clinorotation. We demonstrate differences in the content of these membrane components of clinorotated and 1 g controls. The results indicate the high sensitivity of root plasma membrane to altered gravity conditions. [ABSTRACT FROM AUTHOR]

Objectives: To elucidate the role of FSH1 (family of serine hydrolase) in lipid homeostasis. Results: Proteins in various species containing alpha/beta hydrolase domain are known to be involved in lipid metabolism. In silico analysis of the FSH1 gene in Saccharomyces cerevisiae revealed the presence of alpha/beta hydrolase domain (ABHD) and a lipase motif (GXSXG), however its function in lipid metabolism remained elusive. The overexpression of FSH1 in WT and fsh1Δ cells showed a significant reduction in the cellular phospholipid levels and an increase in the triacylglycerol levels and lipid droplet (LD) number. Furthermore, the purified recombinant protein Fsh1p was identified as a lysophospholipase that specifically acts on lysophosphatidylserine (LPS) and impacts the lipid homeostasis in S. cerevisiae. Conclusions: These results depicted that Fsh1p has a role on lipid homeostasis and is a lysophospholipase that hydrolyzes lysophosphatidylserine (LPS). [ABSTRACT FROM AUTHOR]

A bacterial strain designated NYYP31T was isolated from the leaves of an annual halophytes, Suaeda corniculata Bunge, collected from the southern edge of the Gurbantunggut desert, north-west China. Strain NYYP31T was Gram-staining negative, strictly aerobic, rod-shaped, non-motile, and non-spore-forming. Growth was observed at 4–42 °C, at pH 5.0–10.0, in the presence of up to 8% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences and coding sequences of 92 protein clusters showed that strain NYYP31T should be assigned to the genus Sphingobacterium. 16S rRNA gene sequence similarity analysis showed that strain NYYP31T was most closely related to the type strain of Sphingobacterium daejeonense (97.9%) and Sphingobacterium lactis (97.7%). The predominant isoprenoid quinone was MK-7. The major fatty acids were identified as iso-C15:0, iso-C17:0 3-OH and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The polar lipids were phosphatidylethanolamine, two unidentified phospholipids, three unidentified lipids, three unidentified amino phospholipids, and two unidentified glycolipids. The genomic DNA G + C content was 36.4 mol%. The average nucleotide identity (ANI) values for strain NYYP31T to the type strains of S. daejeonense and S. lactis were 77.9 and 74.1%, respectively, which were below the cut-off level (95–96%) for species delineation. Based on the above results, strain NYYP31T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium endophyticum sp. nov. is proposed. The type strain is NYYP31T (= CGMCC 1.16979T = NBRC 114258T). [ABSTRACT FROM AUTHOR]

Phosphate plays a crucial role in phospholipid metabolism and it is transported by the phosphate (Pi) transporters. Phospholipids are building blocks of the cell membrane, and essential for cell growth; however, the role of phosphate transporters in lipid metabolism remains elusive. The present study shows that the deletion of Pi transporters exhibited an increase in both phospholipid and neutral lipid levels when compared to wild type. The mRNA expressions of genes involved in phospholipid synthesis (CKI1, EKI1, CHO2, and OPI3) were increased due to de-repression of the transcription factors (INO2 and INO4). Neutral lipid levels (triacylglycerol and sterol ester) and their synthesizing genes (LRO1, ARE2, ACC1, and FAS1) were also increased, resulting in lipid droplet accumulation in Pi transporter mutants. Interestingly, phospholipase (PLC1) and histone acetyltransferase genes (ESA1, EAF1, YNG1, YNG2, and GCN5) were also found to be significantly increased, leading to dysregulation of lipid levels in Pi transporter mutants. In summary, our results suggest that the Pi transporters are involved in lipid droplet and membrane lipid homeostasis. [ABSTRACT FROM AUTHOR]

Purpose: Several clinical studies suggested that light-to-moderate alcohol intake could alleviate nonalcoholic fatty liver disease (NAFLD), but the underlying mechanism is still poorly understood. Methods: Mice fed a high-fat diet (HFD) were submitted or not to moderate ethanol intake for 3 months (ca. 10 g/kg/day) via drinking water. Biochemical, analytical and transcriptomic analyses were performed in serum and liver. Results: Serum ethanol concentrations in ethanol-treated HFD mice comprised between 0.5 and 0.7 g/l throughout the experiment. NAFLD improvement was observed in ethanol-treated HFD mice as assessed by reduced serum transaminase activity. This was associated with less microvesicular and more macrovacuolar steatosis, the absence of apoptotic hepatocytes and a trend towards less fibrosis. Liver lipid analysis showed increased amounts of fatty acids incorporated in triglycerides and phospholipids, reduced proportion of palmitic acid in total lipids and higher desaturation index, thus suggesting enhanced stearoyl-coenzyme A desaturase activity. mRNA expression of several glycolytic and lipogenic enzymes was upregulated. Genome-wide expression profiling and gene set enrichment analysis revealed an overall downregulation of the expression of genes involved in collagen fibril organization and leukocyte chemotaxis and an overall upregulation of the expression of genes involved in oxidative phosphorylation and mitochondrial respiratory chain complex assembly. In addition, mRNA expression of several proteasome subunits was upregulated in ethanol-treated HFD mice. Conclusions: Moderate chronic ethanol consumption may alleviate NAFLD by several mechanisms including the generation of non-toxic lipid species, reduced expression of profibrotic and proinflammatory genes, restoration of mitochondrial function and possible stimulation of proteasome activity. [ABSTRACT FROM AUTHOR]

Absolute and relative content and composition of fatty acids, total lipids, and phospholipids, as principal constituents of cell membranes, were examined on vegetative buds of deciduous trees and shrubs throughout the summer and autumn–winter seasons under climatic conditions of the cryolithozone of Yakutia. Lipid metabolism was found to play an essential role in plants' adaptation to low autumnal and winter temperatures in the permafrost zone of Yakutia. The content of phosphatidylcholine in leaf buds of the birch Betula pendula Roth and the shrub Alnus alnobetula subsp. fruticosa (Rupr.) Raus increased throughout the observation period from 9.9 to 23.4 mg/g dry wt. In the autumn–winter period, the composition of fatty acids in the bud lipids of both species was characterized by a high content of unsaturated C18:2 and C18:3 acids. Biosynthesis of fatty acids in buds of deciduous trees and shrubs at a low temperature was apparently controlled by ω3-desaturase, whose activity elevated the content of α-linolenic acid from 2.9 to 5.7 mg/g in B. pendula and from 1.6 to 4.8 mg/g dry wt in A. alnobetula subsp. fruticosa. The seasonal decrease in air temperature was accompanied by an increase in the unsaturation coefficient (k) from 0.9 to 2.3 in B. pendula and from 1.4 to 1.8 in A. alnobetula subsp. fruticosa. It is proposed that the high content of polyunsaturated fatty acids in the autumn–winter period in vegetative buds of the examined woody plants is determined by a complex of climatic factors of the permafrost zone, such as a sharply contrasting day and night temperatures during plant dormancy, extremely low air temperature in winter (down to –60°С), and a short daylight period at this time of the year. [ABSTRACT FROM AUTHOR]

A final product of fish production, the skeletal muscle of fish, is a source of animal protein, phospholipids, and polyunsaturated fatty acids, which are essential for human consumption. The effects of rearing conditions (seasonal temperature and oxygen regimens) and physiological state (infectious status) on the lipid composition of the skeletal muscle of two-year-old rainbow trout Oncorhynchus mykiss grown in cages on a natural lake were studied. It was detected that the rate of body growth in trout juveniles decreased with increased water temperature, sporadic bacterial infection, and subsequent antimicrobial therapy. In addition, an excessive accumulation of reserve lipids (triacylglycerols) and increased saturation of the membrane lipids in fish muscle were shown. Dietary supplementation with an antioxidant additive including dihydroquercetin and arabinogalactan was used to mitigate the impact of exogenous factors and bacterial infection. It was shown that the lipid composition and unsaturated fatty-acid content were more stable with supplement-feeding of the fish tissue, which indicates better consumption characteristics and a balanced nutrient composition of the resulting fish product. [ABSTRACT FROM AUTHOR]

Bardoxolone methyl (CDDO-Me), a synthetic derivative of the naturally occurring triterpenoid oleanolic acid, displays strong antioxidant, anticancer and anti-inflammatory activities, according to different bibliographical sources. However, the understanding of its molecular mechanism is missing. Furthermore, CDDO-Me has displayed a significant cytotoxicity against various types of cancer cells. CDDO-Me has a noticeable hydrophobic character and several of its effects could be attributed to its ability to be incorporated inside the biological membrane and therefore modify its structure and specifically interact with its components. In this study, we have used full-atom molecular dynamics to determine the location, orientation and interactions of CDDO-Me in phospholipid model membranes. Our results support the location of CDDO-Me in the middle of the membrane, it specifically orients so that the cyano group lean towards the phospholipid interface and it specifically interacts with particular phospholipids. Significantly, in the membrane the CDDO-Me molecules specifically interact with POPE and POPS. Moreover, CDDO-Me does not aggregates in the membrane but it forms a complex conglomerate in solution. The formation of a complex aggregate in solution might hamper its biological activity and therefore it should be taken into account when intended to be used in clinical assays. This work should aid in the development of these molecules opening new avenues for future therapeutic developments. [ABSTRACT FROM AUTHOR]

Introduction of microfluidic mixing technique opens a new door for preparation of the liposomes and lipid-based nanoparticles by on-chip technologies that are applicable in a laboratory and industrial scale. This study demonstrates the role of phospholipid bilayer fragment as the key intermediate in the mechanism of liposome formation by microfluidic mixing in the channel with "herring-bone" geometry used with the instrument NanoAssemblr. The fluidity of the lipid bilayer expressed as fluorescence anisotropy of the probe N,N,N-Trimethyl-4-(6-phenyl-1,3,5-hexatrien-1-yl) was found to be the basic parameter affecting the final size of formed liposomes prepared by microfluidic mixing of an ethanol solution of lipids and water phase. Both saturated and unsaturated lipids together with various content of cholesterol were used for liposome preparation and it was demonstrated, that an increase in fluidity results in a decrease of liposome size as analyzed by DLS. Gadolinium chelating lipids were used to visualize the fine structure of liposomes and bilayer fragments by CryoTEM. Experimental data and theoretical calculations are in good accordance with the theory of lipid disc micelle vesiculation. [ABSTRACT FROM AUTHOR]

Objective: Choline and docosahexaenoic acid (DHA) are essential nutrients for preterm infant development. They are metabolically linked via phosphatidylcholine (PC), a constitutive plasma membrane lipid and the major transport form of DHA in plasma. Plasma choline and DHA-PC concentrations rapidly decline after preterm birth. To improve preterm infant nutrition, we evaluated combined compared to exclusive choline and DHA supplementation, and standard feeding. Design: Randomized partially blinded single-center trial. Setting: Neonatal tertiary referral center in Tübingen, Germany. Patients: 24 inborn preterm infants < 32 week postmenstrual age. Interventions: Standard nutrition (control) or, additionally, enteral choline (30 mg/kg/day), DHA (60 mg/kg/day), or both for 10 days. Single enteral administration of 3.6 mg/kg [methyl-D9-] choline chloride as a tracer at 7.5 days. Main outcome measures: Primary outcome variable was plasma choline following 7 days of supplementation. Deuterated and unlabeled choline metabolites, DHA-PC, and other PC species were secondary outcome variables. Results: Choline supplementation increased plasma choline to near-fetal concentrations [35.4 (32.8–41.7) µmol/L vs. 17.8 (16.1–22.4) µmol/L, p < 0.01] and decreased D9-choline enrichment of PC. Single DHA treatment decreased DHA in PC relative to total lipid [66 (60–68)% vs. 78 (74–80)%; p < 0.01], which was prevented by choline. DHA alone increased DHA-PC only by 35 (26–45)%, but combined treatment by 63 (49–74)% (p < 0.001). D9-choline enrichment showed preferential synthesis of PC containing linoleic acid. PC synthesis via phosphatidylethanolamine methylation resulted in preferential synthesis of DHA-containing D3-PC, which was increased by choline supplementation. Conclusions: 30 mg/kg/day additional choline supplementation increases plasma choline to near-fetal concentrations, dilutes the D9-choline tracer via increased precursor concentrations and improves DHA homeostasis in preterm infants. Trial registration: clinicaltrials.gov. Identifier: NCT02509728. [ABSTRACT FROM AUTHOR]

In this study, combined genome, transcriptome, and metabolome analysis was performed for eight Saccharomyces cerevisiae mitochondrial respiration-deficient mutants. Each mutant exhibited a unique nuclear genome mutation pattern; the nuclear genome mutations, and thus potentially affected genes and metabolic pathways, showed a co-occurrence frequency of ≤ 3 among the eight mutants. For example, only a lipid metabolism-related pathway was likely to be affected by the nuclear genome mutations in one of the mutants. However, large deletions in the mitochondrial genome were the shared characteristic among the eight mutants. At the transcriptomic level, lipid metabolism was the most significantly enriched Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway for differentially expressed genes (DEGs) co-occurring in both ≥ 4 and ≥ 5 mutants. Any identified DEG enriched in lipid metabolism showed the same up-/down-regulated pattern among nearly all eight mutants. Further, 126 differentially expressed lipid species (DELS) were identified, which also showed the same up-/down-regulated pattern among nearly all investigated mutants. It was conservatively demonstrated that the similar change pattern of lipid metabolism in the entire investigated mutant population was attributed to mitochondrial dysfunction. The change spectrum of lipid species was presented, suggesting that the number and change degree of up-regulated lipid species were higher than those of down-regulated lipid species. Additionally, energy storage lipids increased in content and plasma-membrane phospholipid compositions varied in the relative proposition. The results for the genome, transcriptome, and lipidome were mutually validated, which provides quantitative data revealing the roles of mitochondria from a global cellular perspective. [ABSTRACT FROM AUTHOR]

Aggregation of amyloid- β (Aβ) peptides, cleaved from the amyloid precursor protein, is known as a precursor of the Alzheimer's disease (AD). It is also known that Alzheimer's disease is characterized by a substantial decrease of the amount of polyunsaturated lipids in the neuronal membranes of the frontal gray matter. To get insight into possible interconnection of these phenomena, we have carried out molecular dynamics simulations of two fragments of A β peptide, A β 1 - 28 and A β 26 - 40 , in four different lipid bilayers: two monocomponent ones (14:0-14:0 PC, 18:0-22:6 PC), and two bilayers containing mixtures of 18:0-18:0 PE, 22:6-22:6 PE, 16:0-16:0 PC and 18:1-18:1 PC lipids of composition mimicking neuronal membranes in a "healthy" and "AD" brain. The simulations showed that the presence of lipids with highly unsaturated 22:6cis fatty acids chains strongly affects the interaction of amyloid- β peptides with lipid membranes. The polyunsaturated lipids cause stronger adsorption of A β -peptides by the membrane and lead to weaker binding between peptides when the latter form aggregates. This difference in the behaviour observed in monocomponent bilayers is propagated in a similar fashion to the mixed membranes mimicking composition of neuronal membranes in "healthy" and "AD" brains, with "healthy" membrane having higher fraction of polyunsaturated lipids. Our simulations give strong indication that it can be physical–chemical background of the interconnection between amyloid fibrillization causing Alzheimer's disease, and content of polyunsaturated lipids in the neuronal membranes. [ABSTRACT FROM AUTHOR]

The composition of lipids and fatty acids (FAs) and changes in their content in needles of summer- and autumn-vegetating conifer trees growing in the cryolithozone of Yakutia have been studied by thin-layer and gas-liquid chromatography–mass spectrometry. A comparative analysis of the content of total lipids (TL) and phospholipids (PL) has been carried out, and the FA composition of TL in needles of Pinus sylvestris L. and Picea obovata Ledeb. has been determined for summer and autumn periods. In the course of adaptation to low autumn temperatures of the Yakutian cryolithozone, the TL content in needles of P. sylvestris and P. obovata significantly (by 30%) increased compared to the summer season. During this period, the phosphatidylcholine content in needles of both species also increased from 13.8 to 31 mg/g dry wt. For both species, the FA lipid composition of needles included a high content of species-specific unsaturated polymethylene-interrupted fatty acids (Δ5-UPIFA). Increase in the content of TL, PL, total FA, and Δ5-UPIFA observed during a temperature drop significantly exceeds that in plants of these species growing in other parts of Siberia. This fact is probably caused by features of low-temperature adaptation of plants in permafrost ecosystems of Yakutia. [ABSTRACT FROM AUTHOR]

Summary: Our study focused on the associations of metabolites with BMD and osteoporosis, finding that several metabolites are associated with BMD, and metabolites combined with bone turnover markers tend to be more sensitive in distinguishing osteoporosis in both males and postmenopausal females, which might be meaningful for the early diagnosis of osteoporosis. Introduction: Our study aimed to evaluate the association of metabolites with bone, trying to find new metabolic markers that are distinguishing for low bone mineral density (BMD). Methods: Our study recruited 320 participants, including 138 males and 182 postmenopausal females from the Shanghai area. Bone turnover markers (BTMs), including osteocalcin, PINP and β-CTX, and other biochemical traits were tested. BMD values of the lumber spine (L1–4), femoral neck and total hip were determined using dual-energy X-ray absorptiometry and the serum metabolome profiles including 221 metabolites from five groups (acylcarnitines, amino acids, biogenic amines, glycerophospholipids, sphingolipids and hexose) were assessed by mass spectrometry. Results: No visual separation in the metabolic profiles between different BMD groups was observed in principal component analysis (PCA) or partial least squares discriminant analysis (PLS-DA) models. We compared metabolites in three groups with different BMD levels in males and postmenopausal females separately and further filtering these metabolites via random forest-based feature selection, a commonly applied machine learning algorithm which could select the features with the greatest impact on osteoporosis, then metabolites with the highest importance (≥ 5%) (5 in males and 9 in postmenopausal females) were selected to construct better models for osteoporosis classification. After adding these selected metabolites to the model, the area under the curve (AUC) of receiver operating characteristic (ROC) curves increased significantly (BTMs: AUC 0.729, 95% CI 0.647–0.802, p < 0.0001, model 1: AUC = 0.828, 95% CI 0.754–0.888, p < 0.0001; model 1 versus model of BTMs: p = 0.0158) compared to the AUC of the BTM-only model in males. Similar results were also observed in postmenopausal females (BTMs: AUC = 0.638, 95% CI 0.562–0.708, p = 0.0025; model 2: AUC = 0.741, 95% CI 0.669–0.803, p < 0.0001; model 1 versus model of BTMs: p = 0.0182). Conclusion: Metabolites combined with traditional BTMs tend to better markers for distinguishing osteoporosis in both males and postmenopausal females than BTMs alone. [ABSTRACT FROM AUTHOR]

An ultrahigh-pressure supercritical fluid extraction method was optimized and applied to extract seed oil lipids from two moringa species, namely Moringa oleifera (MO) and Moringa peregrina (MP). A full-factorial design was used to investigate the direct and interaction influence of pressure and temperature in the range of 40 to 80 MPa and 40 to 70 °C, respectively, on the extracted amount of oil from crushed seeds. The results revealed that pressure has a significant positive influence on the extracted amount of oil. The best extraction condition using neat CO2 was found at 80 MPa and 57 °C, yielding 396 ± 23 and 529 ± 26 mg oil per gram of seeds for MO and MP, respectively. An extraction kinetics study revealed a mainly solubility-controlled extraction of oil, and 28 g of CO2 was required to extract 400 mg of oil per gram of seeds of MO using the developed method. Addition of ethanol to the sample prior to the extraction increased the proportion of extractable polar lipids as well as the total amount of extracted oil. The developed method increased the extracted amount of oil twofold compared to a reference method based on solvent sonication. The obtained oil consisted mainly of glycerolipids, sterol esters, and phospholipids. Phospholipids, campesterol, and stigmasterol ester concentrations were found to be higher in MO while cholesterol ester was more abundant in MP. [ABSTRACT FROM AUTHOR]

Local anesthetics (LAs) are known to act on membrane level; however, the molecular mechanism of their activity is still not fully understood. One hypothesis holds that these drugs can incorporate into lipid membrane of nerve cells and in this way change conformation of channel proteins responsible for transport of sodium ions. However, the action of anesthetics is not limited to nerve cells. These drugs also affect other types of cells and organelles, causing severe side effects. In this paper, we applied Langmuir monolayers-as model of cellular membranes-and investigated interactions between selected amide-type local anesthetics (lidocaine prilocaine, mepivacaine and ropivacaine, in the form of hydrochlorides) and lipid components of natural membranes: cholesterol, POPC and cardiolipin (CL) and their mixtures (POPC/cholesterol and POPC/CL/cholesterol), which can serve as simplified models of nerve cell membranes, erythrocytes, and mitochondria. The influence of the drug was monitored by registering the surface pressure (π) as a function of surface area per molecule (A) in a monolayer in the presence of the drug in the subphase. The structure of lipid monolayers on subphases containing and devoid of the studied drugs were visualized with Brewster angle microscopy (BAM). Langmuir monolayer studies complemented with surface visualization technique reveal the expansion and fluidization of lipid monolayers, with the most pronounced effect observed for cardiolipin. In mixed systems, the effect of LAs was found to depend on cholesterol proportion. The observed fluidization of membranes by local anesthetics may negatively affect cells functioning and therefore can explain side effects of these drugs both on the cardiovascular and nervous systems. [ABSTRACT FROM AUTHOR]

The aim of the study was to increase knowledge regarding baseline biology of Arctic mussels (Mytilus spp.) in terms of lipid class content at different stages of reproductive development throughout the year. Lipid composition in the mantle and digestive glands were studied in mussels from the intertidal and subtidal zones of mussel beds located in the Norwegian Sea and the White Sea. Thin-layer chromatography was used to quantify phospholipids, triacylglycerols, sterols and their esters. The differences in climatic and hydrological conditions between the studied geographical locations of mussel beds were reflected not only in the timing and duration of the mussel’s reproductive stages, mainly active gametogenesis (stage II) and maturity (stage III), but also in the lipid composition of mussel mantle and digestive gland. The differences in environmental conditions between intertidal and subtidal zones of the studied mussel beds were also reflected in the lipid composition of mussels from both geographic locations, and determined the modifications of their lipid composition during the reproductive development. Although environmental conditions caused specificity in the distribution of the lipid composition in the mantle and digestive gland of Arctic Mytilus spp., the lipid composition variations that accompany the reproductive processes in bivalve mollusks were not affected. [ABSTRACT FROM AUTHOR]

Background: Docosahexaenoic (C22:6) and arachidonic (C20:4) acids are long-chain polyunsaturated fatty acids (LC-PUFA) essential to neonatal development, being present in the glycerophospholipids of all organs, particularly the brain. In plasma, LC-PUFAs are mainly present in lipoprotein lipids, which are neutral lipids (triglycerides and cholesterol esters) and glycerophospholipids, like choline containing phosphatidylcholine (PC).Purpose: To guide future supplementation strategies of C22:6 and C20:4 in combination with choline, we determined the distribution of C20:4 and C22:6 between PC and neutral lipid.Methods: Preterm infant plasma (N = 59, postmenstrual age [PMA] 33.9 wk (32.4-36.0)) and cord plasma (N = 34, PMA 34.0 wk (30.86-38.4)) were investigated. PC and neutral lipids were extracted and analyzed using tandem mass spectrometry and gas chromatography, respectively. Data are reported as medians and 25th/75th percentiles.Results: In cord blood, C20:4-PC and C22:6-PC comprised 36.1% (34.2-38.6) and 10.2% (8.8-12.8) of total PC, respectively. In preterm infant plasma, values were only 20.8% (19.2-23.1) and 5.7% (5.2-6.0), respectively (p < 0.001 each). Nevertheless, in preterm infant plasma, 80.6% (77.6-83.0) of C20:4 and 86.0% (83.0-88.9) of C22:6 were found in PC. These values exceeded the proportions of C20:4 and C22:6 in PC of cord plasma [71.3% (67.8-72.9) and 79.2% (75.2-85.4), respectively] (p < 0.0001 each).Conclusion: Irrespective of the low proportions of C20:4-PC and C22:6-PC in preterm infant plasma lipids, PC is the major transporter for C20:4 and C22:6. Our data support the hypotheses that choline deficiency may impair end-organ availability of these LC-PUFA in preterm infants. Therefore, supplementation of C20:4 and C22:6 might better be accompanied by choline supplementation. [ABSTRACT FROM AUTHOR]

A novel method for rapid screening of antimicrobial peptides (AMPs) was developed by using immobilized lipid affinity capture (ILAC) coupled with LC-MS. Phospholipid (PL) mixture containing phosphatidyl glycerol (PG): phosphatidyl ethanolamine (PE) (4:1), roughly mimic the PL composition of Gram-positive bacterial membrane, was covalently immobilized on magnetic particles (MPs). PL monolayer immobilized on MPs was used as a matrix for capturing of the membrane-disruptive AMPs. Hominicin, a new AMP against Gram-positive bacteria, was successfully captured by ILAC from the peptide pool of Staphylococcus hominis MBBL 2-9. The hominicin was identified by the comparative analysis of LC-MS 2Dprofiles of peptides captured by bare and PL-immobilized MPs. This is the first report for the development of rapid AMP screening method using lipid-immobilized MPs and LC-MS which will be a promising tool for discovery of various kinds of AMPs. [ABSTRACT FROM AUTHOR]

Lipid membrane interfaces are complex environments that host essential cellular processes such as binding of proteins or drug molecules. A key open question is how water molecules at the interface of membranes with anionic lipids participate in protein binding. To address this question, we studied the dynamics of water hydrogen bonding at the interface of membranes composed of phosphatidylcholine and phosphatidylglycerol, and implemented an algorithm to identify hydrogen-bonded networks at the interface of a lipid membrane, and to characterize their dynamics and linear connections. We find that the membrane interface is characterized by a rich network of hydrogen-bonded water chains that bridge lipid headgroups, some of which form transient lipid clusters. Water-mediated bridges between with lipid phosphate groups are dynamic, with residence lifetimes on the order of picoseconds. These clusters of water/lipid headgroup hydrogen bonds could provide a platform for the binding of proteins or of drug molecules with cationic groups. [ABSTRACT FROM AUTHOR]

How proteins are targeted to lipid droplets (LDs) and distinguish the LD surface from the surfaces of other organelles is poorly understood, but many contain predicted amphipathic helices (AHs) that are involved in targeting. We have focused on human perilipin 4 (Plin4), which contains an AH that is exceptional in terms of length and repetitiveness. Using model cellular systems, we show that AH length, hydrophobicity, and charge are important for AH targeting to LDs and that these properties can compensate for one another, albeit at a loss of targeting specificity. Using synthetic lipids, we show that purified Plin4 AH binds poorly to lipid bilayers but strongly interacts with pure triglycerides, acting as a coat and forming small oil droplets. Because Plin4 overexpression alleviates LD instability under conditions where their coverage by phospholipids is limiting, we propose that the Plin4 AH replaces the LD lipid monolayer, for example during LD growth. [ABSTRACT FROM AUTHOR]

Since 2003, molecular dynamics simulations of lipid bilayers have provided valuable insights into the mechanisms underlying electropermeabilization (electroporation)-an electric field-induced increase in the permeability of biological membranes. The convention in these studies has been to apply the electric field normal to the plane of the membrane. In a typical electroporation application, however, where the electric field is reasonably uniform and unidirectional, the field is perpendicular to the membrane only at a few locations-for spherical cells only at the poles of the cells along the axis defined by the direction of the electric field. Everywhere else on the cell surface the field is applied at an angle that is oblique to the plane of the membrane. On a microscopic level, the invaginations and protrusions that characterize a living cell membrane also present many angles to the applied electric field. Here we report the results of molecular dynamics simulations of lipid electropore formation when the electric field is not normal to the membrane surface, which show that the tangential component of the field has a small but non-zero effect. [ABSTRACT FROM AUTHOR]