Neutral Lipids (neutral + lipid)

Distribution by Scientific Domains


Selected Abstracts


The Structure of a Novel Neutral Lipid,A from the Lipopolysaccharide of Bradyrhizobium elkanii Containing Three Mannose Units in the Backbone

CHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2010
Iwona Komaniecka Dr.
Abstract The chemical structure of the lipid,A of the lipopolysaccharide (LPS) from Bradyrhizobium elkanii USDA 76 (a member of the group of slow-growing rhizobia) has been established. It differed considerably from lipids,A of other Gram-negative bacteria, in that it completely lacks negatively charged groups (phosphate or uronic acid residues); the glucosamine (GlcpN) disaccharide backbone is replaced by one consisting of 2,3-dideoxy-2,3-diamino- D -glucopyranose (GlcpN3N) and it contains two long-chain fatty acids, which is unusual among rhizobia. The GlcpN3N disaccharide was further substituted by three D -mannopyranose (D -Manp) residues, together forming a pentasaccharide. To establish the structural details of this molecule, 1D and 2D,NMR spectroscopy, chemical composition analyses and high-resolution mass spectrometry methods (electrospray ionisation Fourier-transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) and tandem mass spectrometry (MS/MS)) were applied. By using 1D and 2D,NMR spectroscopy experiments, it was confirmed that one D -Manp was linked to C-1 of the reducing GlcpN3N and an ,-(1,6)-linked D -Manp disaccharide was located at C-4, of the non-reducing GlcpN3N (,-linkage). Fatty acid analysis identified 12:0(3-OH) and 14:0(3-OH), which were amide-linked to GlcpN3N. Other lipid,A constituents were long (,-1)-hydroxylated fatty acids with 26,33 carbon atoms, as well as their oxo forms (28:0(27-oxo) and 30:0(29-oxo)). The 28:0(27-OH) was the most abundant acyl residue. As confirmed by high-resolution mass spectrometry techniques, these long-chain fatty acids created two acyloxyacyl residues with the 3-hydroxy fatty acids. Thus, lipid,A from B. elkanii comprised six acyl residues. It was also shown that one of the acyloxyacyl residues could be further acylated by 3-hydroxybutyric acid (linked to the (,-1)-hydroxy group). [source]


Lipid composition of retailed organic, free-range and conventional chicken breasts

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2007
Kishowar Jahan
Summary Lipid fractions of 20 retailed chicken breasts were correlated with production system: organic, corn-fed, free-range and conventional. Neutral lipid (NL), phospholipid (PL) and free fatty acids (FFA) were examined separately. Influence of production systems was found more pronounced in PL composition than NLs. Corn-fed and free-range NLs had higher contents of nutritionally beneficial eicosapentanoic acid (C20:5 n-3) and docosahexanoic acid (C22:6 n-3) than organic and conventional. Lower polyunsaturated fatty acids in organic and free-range PLs could be beneficial for tissue stability. Principal component product space for PLs showed clear clustering related to product category. In contrast, this was not observed with FFA except in the partial least square regression product space suggesting influences on NLs and PLs and FFA. PLs had lower contents of arachidonic acid than in earlier studies. Advantages were observed in lipid fractionation using advanced sorbent extraction matrices. [source]


NeoHepatocytes From Alcoholics and Controls Express Hepatocyte Markers and Display Reduced Fibrogenic TGF-,/Smad3 Signaling: Advantage for Cell Transplantation?

ALCOHOLISM, Issue 4 2010
Sabrina Ehnert
Background:, Liver transplantation is the only definitive treatment for end stage liver disease. Donor organ scarcity raises a growing interest in new therapeutic options. Recently, we have shown that injection of monocyte-derived NeoHepatocytes can increase survival in rats with extended liver resection. In order to apply this technology in humans with chronic liver diseases in an autologous setting, we generated NeoHepatocytes from patients with alcoholic liver disease and healthy controls and compared those to human hepatocytes. Methods:, We generated NeoHepatocytes from alcoholics with Child A and B cirrhosis and healthy controls. Hepatocytes marker expression and transforming growth factor (TGF)-, signaling was investigated by RT-PCR, Western blot, immunofluorescent staining, and adenoviral reporter assays. Glucose and urea was measured photometrically. Phase I and II enzyme activities were measured using fluorogenic substrates. Neutral lipids were visualized by Oil Red O staining. Results:, There was no significant difference in generation and yield of NeoHepatocytes from alcoholics and controls. Hepatocyte markers, e.g., cytokeratin18 and alcohol dehydrogenase 1, increased significantly throughout differentiation. Glucose and urea production did not differ between alcoholics and controls and was comparable to human hepatocytes. During differentiation, phase I and II enzyme activities increased, however remained significantly lower than in human hepatocytes. Fat accumulation was induced by treatment with insulin, TGF-, and ethanol only in differentiated cells and hepatocytes. TGF-, signaling, via Smad transcription factors, critically required for progression of chronic liver disease, was comparable among the investigated cell types, merely expression of Smad1 and -3 was reduced (,30 and ,60%) in monocytes, programmable cells of monocytic origin, and NeoHepatocytes. Subsequently, expression of TGF-, regulated pro-fibrogenic genes, e.g., connective tissue growth factor and fibronectin was reduced. Conclusions:, Generation of NeoHepatocytes from alcoholics, displaying several features of human hepatocytes, offers new perspectives for cell therapeutic approaches, as cells can be obtained repeatedly in a noninvasive manner. Furthermore, the autologous setting reduces the need for immunosuppressants, which may support recovery of patients which are declined for liver transplantation. [source]


Influence of environmental temperature on composition of lipids in edible flesh of rainbow trout (Oncorhynchus mykiss)

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2003
Antonella Calabretti
Abstract The adaptative changes in the fatty acid composition of the main lipid classes in rainbow trout (Oncorhynchus mykiss) edible flesh in response to environmental variation in water temperature were investigated. The research was carried out on intensively farmed trout sampled at different times of the year. Neutral lipids (NL), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were separated using flash chromatography. Compared with summer acclimatisation, a decrease in neutral lipids of about 19% was observed in winter, accompanied by increases in phosphatidylethanolamine and phosphatidylcholine of about 41 and 29%, respectively. The metabolic adjustment in cold adaptation caused an increase in the levels of unsaturated fatty acids and monoenes of the oleic acid ,9 family and an increase in the levels of unsaturated fatty acids of the linoleic acid ,3 family. At the same time a reduction in the levels of saturated and monounsaturated fatty acids of the oleic acid ,9 family was observed. This pattern turned out to be particularly evident in phosphatidylcholine. The net result of these changes in composition was a significant increase in the polyunsaturated/saturated and polyunsaturated/monoenic fatty acid ratios in the edible flesh. Copyright © 2003 Society of Chemical Industry [source]


Supplemental dietary flaxseed oil affects both neutral and phospholipid fatty acids in cultured tilapia

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2008
Nilson E. de Souza
Abstract This work aimed to evaluate the neutral lipid (NL) and phospholipid (PL) classes in tilapia (Oreochromis niloticus) muscle tissue. Tilapias were raised in captivity for a period of 5,months with increasing levels (0, 1.25, 2.50, 3.75, and 5.00%) of flaxseed oil [source of ,-linolenic acid (LNA), 18:3n -3] in substitution for sunflower oil (control). The NL/PL ratio was 1.9, and 45,fatty acids were determined for both classes of lipid. The class totals of n -3 acids always increased in all treatments, while the totals for n -6 acids always decreased (p,<0.05). For a given level of flaxseed oil, the LNA contents were consistently higher, including EPA (20:5n -3) and DHA (22:6n -3). Arachidonic acid (20:4n -6) remained high in the PL but was reduced as levels of dietary flaxseed oil were increased. The n -6/n -3 ratios decreased significantly with the rise in flaxseed oil content in all treatments, and highly unsaturated fatty acid contents increased with the levels of flaxseed oil. Overall, the influence of flaxseed oil on the fatty acid composition in the contributing NL and PL classes was to increase n -3 PUFA, thus raising the nutritional value of this freshwater fish meat and, consequently, contributing to the health of consumers. [source]


Comparison of dietary phospholipids and neutral lipids: effects on gut, liver and pancreas histology in Atlantic cod (Gadus morha L.) larvae

AQUACULTURE NUTRITION, Issue 1 2009
P.-A. WOLD
Abstract The aim of the present study was to compare effects of dietary n-3 highly unsaturated fatty acids (HUFA) being incorporated in the phospholipid (PL) or in the neutral lipid (NL) fraction of the larval feed, on larval growth and histology of digestive organs in Atlantic cod (Gadus morhua L.) larvae. Three isoproteic and isolipidic diets, labelled according to the percentage of n-3 docosahexaenoic acid and eicosapentaenoic acid contained in NL1 or in PL1 and PL3 of the diets, were fed to cod larvae from 17 days post hatching (dph) to 45 dph. In the liver, hepatocytes and their nuclei were smaller in NL1 larvae compared with the PL larvae; the mitochondrial membrane structures were less dense and the amount of lipids observed in the liver was significantly higher in NL1 larvae compared with the PL3 larvae. The liver and gut size was related to larval size, with no differences between the larval groups. The results demonstrated that the essential fatty acids were more beneficial for cod larvae when they were incorporated in the dietary polar PL rather than in the NL, and that the n-3 HUFA requirements in cod larvae is possibly higher than that in the PL1 diet. [source]


Short-term dietary supplementation with the microalga Parietochloris incisa enhances stress resistance in guppies Poecilia reticulata

AQUACULTURE RESEARCH, Issue 2 2010
Anurag Dagar
Abstract Two trials were conducted to determine the effects of dietary enrichments with the microalga Parietochloris incisa, rich in arachidonic acid (ARA), on stress resistance in guppies Poecilia reticulata. The microalga was added to commercial diets as a neutral lipid (NL) extract and its fractions or as broken cells. Experimental diets were applied for a period of 14 days. In trial 1, commercial diets were supplemented with NL (containing 25 mg ARA and 0.11 mg ,-carotene g,1 feed), its triacylglycerol (TAG) fraction (containing 25 mg ARA g,1 feed and no ,-carotene) and the ,-carotene fraction (containing 0.11 mg carotenoid g,1 feed and minute amounts of ARA). Neutral lipid-fed fish demonstrated the highest resistance (P<0.05) to osmotic stress (32-ppt NaCl), followed by fish fed with diets supplemented with TAG and ,-carotene alone, which were more resistant than control (P<0.05). In trial 2, fish fed diets supplemented with higher levels of broken alga (26.1 mg ARA g,1 feed) were more resistant (P<0.05) to stress as compared with fish fed lower ARA (16.3 mg g g,1) or an unsupplemented control diet. We suggest a dietary supplementation with broken P. incisa cells to enhance stress resistance in guppies before a stressful event. [source]


Inhibition of starch synthesis results in overproduction of lipids in Chlamydomonas reinhardtii

BIOTECHNOLOGY & BIOENGINEERING, Issue 2 2010
Yantao Li
Abstract Starch and neutral lipids are two major carbon storage compounds in many microalgae and plants. Lipids are more energy rich and have often been used as food and fuel feedstocks. Genetic engineering of the lipid biosynthesis pathway to overproduce lipid has achieved only limited success. We hypothesize that through blocking the competing pathway to produce starch, overproduction of neutral lipid may be achieved. This hypothesis was tested using the green microalga Chlamydomonas reinhardtii and its low starch and starchless mutants. We discovered that a dramatic increase in neutral lipid content and the neutral lipid/total lipid ratio occurred among the mutants under high light and nitrogen starvation. BAFJ5, one of the mutants defective in the small subunit of ADP-glucose pyrophosphorylase, accumulated neutral and total lipid of up to 32.6% and 46.4% of dry weight (DW) or 8- and 3.5-fold higher, respectively, than the wild-type. These results confirmed the feasibility of increasing lipid production through redirecting photosynthetically assimilated carbon away from starch synthesis to neutral lipid synthesis. However, some growth impairment was observed in the low starch and starchless mutants, possibly due to altered energy partitioning in PSII, with more excitation energy dissipated as heat and less to photochemical conversion. This study demonstrated that biomass and lipid production by the selected mutants can be improved by physiological manipulation. Biotechnol. Bioeng. 2010;107: 258,268. © 2010 Wiley Periodicals, Inc. [source]


Phospholipase stimulates lipogenesis in SZ95 sebocytes

EXPERIMENTAL DERMATOLOGY, Issue 7 2008
S. Schagen
Introduction:, With progressing ageing human sebocytes reduce lipid production. However, the influence of certain aging mechanisms on sebaceous lipid synthesis as well as ways to influence the latter is not fully identified. Certain lipids act as ligands of nuclear receptors such as PPAR. Phospholipase (PLA2) catalyzes the hydrolysis of the sn-2 fatty acyl bond of phospholipids to yield free fatty acid and lysophospholipid. It has been hypothesized that PPAR may be activated by hydrolysis products of phospholipids and also by eicosanoids obtained through PLA2 activity. Materials and Methods:, A method to quantify sebaceous lipid synthesis of SZ95 sebocytes in vitro was established and the cells were treated by snake venom Bothrops moojeni gel filtration fractions (Botmo GF). Botmo GF fractions were further purified by RP-HPLC, and a fraction with PLA2 activity (Botmo GF11-117) and a fraction without enzymatic activity (Botmo GF11-101) were identified and additionally tested. Results:, Botmo GF fractions increased lipogenesis in SZ95 sebocytes without inducing apparent toxic or apoptotic effects. Botmo GF11-101 (1 ,g/ml) enhanced neutral lipid synthesis by up to 170% and polar lipid synthesis by up to 120%. The enzymatically active PLA2 Botmo GF11-117 (1 ,g/ml) increased synthesis of neutral lipids by up to 200%, and polar lipids by up to 120% compared to untreated SZ95 sebocytes. Conclusion:, PLA2 activation or suppression could be important for human sebaceous lipogenesis. PLA2 modifiers may be attractive for skin lipid research and pharmacological/cosmetic products. [source]


Characterization of 1H NMR detectable mobile lipids in cells from human adenocarcinomas

FEBS JOURNAL, Issue 5 2009
Anna Maria Luciani
Magnetic resonance spectroscopy studies are often carried out to provide metabolic information on tumour cell metabolism, aiming for increased knowledge for use in anti-cancer treatments. Accordingly, the presence of intense lipid signals in tumour cells has been the subject of many studies aiming to obtain further insight on the reaction of cancer cells to external agents that eventually cause cell death. The present study explored the relationship between changes in neutral lipid signals during cell growth and after irradiation with gamma rays to provide arrest in cell cycle and cell death. Two cell lines from human tumours were used that were differently prone to apoptosis following irradiation. A sub-G1 peak was present only in the radiosensitive HeLa cells. Different patterns of neutral lipids changes were observed in spectra from intact cells, either during unperturbed cell growth in culture or after radiation-induced growth arrest. The intensities of triglyceride signals in the spectra from extracted total lipids changed concurrently. The increase in lipid peak intensities did not correlate with the apoptotic fate. Modelling to fit the experimental data revealed a dynamic equilibrium between the production and depletion of neutral lipids. This is observed for the first time in cells that are different from adipocytes. [source]


Peroxisome proliferator-activated receptor ,,retinoid X receptor agonists induce beta-cell protection against palmitate toxicity

FEBS JOURNAL, Issue 23 2007
Karine Hellemans
Fatty acids can stimulate the secretory activity of insulin-producing beta-cells. At elevated concentrations, they can also be toxic to isolated beta-cells. This toxicity varies inversely with the cellular ability to accumulate neutral lipids in the cytoplasm. To further examine whether cytoprotection can be achieved by decreasing cytoplasmic levels of free acyl moieties, we investigated whether palmitate toxicity is also lowered by stimulating its ,-oxidation. Lower rates of palmitate-induced beta-cell death were measured in the presence of l -carnitine as well as after addition of peroxisome proliferator-activated receptor , (PPAR,) agonists, conditions leading to increased palmitate oxidation. In contrast, inhibition of mitochondrial ,-oxidation by etomoxir increased palmitate toxicity. A combination of PPAR, and retinoid X receptor (RXR) agonists acted synergistically and led to complete protection; this was associated with enhanced expression levels of genes involved in mitochondrial and peroxisomal ,-oxidation, lipid metabolism, and peroxisome proliferation. PPAR,,RXR protection was abolished by the carnitine palmitoyl transferase 1 inhibitor etomoxir. These observations indicate that PPAR, and RXR regulate beta-cell susceptibility to long-chain fatty acid toxicity by increasing the rates of ,-oxidation and by involving peroxisomes in fatty acid metabolism. [source]


Heterologous expression of AtClo1, a plant oil body protein, induces lipid accumulation in yeast

FEMS YEAST RESEARCH, Issue 3 2009
Marine Froissard
Abstract Proteomic approaches on lipid bodies have led to the identification of proteins associated with this compartment, showing that, rather than the inert fat depot, lipid droplets appear as complex dynamic organelles with roles in metabolism control and cell signaling. We focused our investigations on caleosin [Arabidopsis thaliana caleosin 1 (AtClo1)], a minor protein of the Arabidopsis thaliana seed lipid body. AtClo1 shares an original triblock structure, which confers to the protein the capacity to insert at the lipid body surface. In addition, AtClo1 possesses a calcium-binding domain. The study of plants deficient in caleosin revealed its involvement in storage lipid degradation during seed germination. Using Saccharomyces cerevisiae as a heterologous expression system, we investigated the potential role of AtClo1 in lipid body biogenesis and filling. The green fluorescent protein-tagged protein was correctly targeted to lipid bodies. We observed an increase in the number and size of lipid bodies. Moreover, transformed yeasts accumulated more fatty acids (+46.6%). We confirmed that this excess of fatty acids was due to overaccumulation of lipid body neutral lipids, triacylglycerols and steryl esters. We showed that the original intrinsic properties of AtClo1 protein were sufficient to generate a functional lipid body membrane and to promote overaccumulation of storage lipids in yeast oil bodies. [source]


Molecular characterization of the role of orphan receptor small heterodimer partner in development of fatty liver,

HEPATOLOGY, Issue 1 2007
Jiansheng Huang
The orphan receptor Small Heterodimer Partner (SHP, NROB2) regulates metabolic pathways, including hepatic bile acid, lipid, and glucose homeostasis. We reported that SHP- deletion in leptin-deficient OB,/, mice increases insulin sensitivity, and prevents the development of fatty liver. The prevention of steatosis in OB,/,/SHP,/, double mutants is not due to decreased body weight but is associated with increased hepatic very-low-density lipoprotein (VLDL) secretion and elevated microsomal triglyceride transfer protein (MTP) mRNA and protein levels. SHP represses the transactivation of the MTP promoter and the induction of MTP mRNA by LRH-1 in hepatocytes. Adenoviral overexpression of SHP inhibits MTP activity as well as VLDL-apoB protein secretion, and RNAi knockdown of SHP exhibits opposite effects. The expression of SHP in induced in fatty livers of OB,/, mice and other genetic or dietary models of steatosis, and acute overexpression of SHP by adenovirus, result in rapid accumulation of neutral lipids in hepatocytes. In addition, the pathways for hepatic lipid uptake and lipogenic program are also downregulated in OB,/,/SHP,/, mice, which may contribute to the decreased hepatic lipid content. Conclusion: These studies demonstrate that SHP regulates the development of fatty liver by modulating hepatic lipid export, uptake, and synthesis, and that the improved peripheral insulin sensitivity in OB,/,/SHP,/, mice is associated with decreased hepatic steatosis. (HEPATOLOGY 2007.) [source]


6-O glucose linoleate supports in vitro human hair growth and lipid synthesis

INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2007
P. Vingler
Synopsis The hair follicle is a very active organ with a complex structure, which produces a hair fibre at a rate of 0.3 mm a day. Accordingly, the hair follicle is highly demanding in energy source, as the hair bulb matrix cells are endowed with one of the highest rates of proliferation in the human body. Moreover, recent data have shown the involvement of lipids in hair follicle function. As in vitro -grown hair follicle keeps producing a hair fibre that closely resembles the natural hair fibre, we decided to use this model to investigate the role of a new of glucose linoleate derivative (6-O-linoleyl- d -glucose: 6-O-GL) as a lipid precursor and energy provider. Our results demonstrated that 6-O-GL was (i) quite stable and surprisingly resistant to oxidative degradation, and (ii) readily taken up and metabolized by the hair follicle into various lipids, namely neutral lipids, ceramides and polar lipids. Moreover, it supported hair follicle growth and survival in a glucose- and linoleic-acid free medium. 6-O-GL thus appeared to be a bi-functional nutrient, ensuring both proper fibre quality and production by the hair follicle. Résumé Le follicule pileux est un organe très actif et d'une structure très complexe, qui produit la tige pilaire au rythme de 0.3 mm par jour. En conséquence, le follicule pileux est très demandeur en ressources énergétiques, les cellules de la matrice bulbaire ayant un des taux de prolifération les plus élevé de l'organisme. De plus des études récentes ont mis en évidence le rôle de lipides dans le fonctionnement du follicule pileux. Puisque le follicule pileux in vitro continue à produire une fibre de qualité identique à celle d'une fibre naturelle, nous avons décidé d'utiliser ce modèle pour étudier le rôle d'un nouveau linoléate de glucose (6-O-linoleyl- d -glucose: 6-O-GL) en tant que précurseur lipidique et source d'énergie. Nos résultats démontrent que le 6-O-GL est très stable et étonnamment résistant à l'auto oxydation, qu'il est capté et métabolisé par le follicule pileux en divers lipides, neutres, polaires et céramides. De plus, le 6-O-GL soutient la croissance et la survie du follicule dans un milieu dépourvu de glucose et d'acide linoléique. Le 6-O-GL apparaît donc comme un agent bi-fonctionnel, permettant au follicule pileux de maintenir in vitro la production de la tige pilaire. [source]


Character of long-chain branching in highly purified natural rubber

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010
Sureerut Amnuaypornsri
Abstract The nature of long-chain branching in natural rubber (NR) from Hevea brasiliensis was analyzed for NR purified by enzymatic deproteinization in the latex state followed by acetone extraction in the solid state to remove the proteins and neutral lipids, respectively. The treatment of purified NR in a toluene solution with a polar solvent, such as methanol or acetic acid, resulted in a clear decrease in the molecular weight, gel content, and Huggins' constant; this was caused by the decomposition of branch points in the purified rubber. This finding clearly showed that long-chain branching in the purified NR was mainly derived from the association of phospholipids linked with both terminal groups in the rubber chain via hydrogen bonds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]


Influence of plasma lipid changes in response to 17,-oestradiol stimulation on plasma growth hormone, somatostatin, and thyroid hormone levels in immature rainbow trout

JOURNAL OF FISH BIOLOGY, Issue 3 2001
F. Mercure
Plasma total lipids were significantly higher in 17,-oestradiol(E2)-treated immature rainbow trout Oncorhynchus mykiss at week 4 after implantation, due to increases in polar and neutral lipids. The lipid classes responding were phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, sterols and sterol esters, in a proportion that approximately reflected the increase in plasma vitellogenin (VtG) levels as measured by a non-competitive enzyme-linked immunosorbent assay (ELISA). Plasma non-esterified fatty acids and triacylglycerol were not affected by E2 treatment. Plasma growth hormone GH levels were increased, and plasma somatostatin-14 (SRIF) levels decreased in E2 -treated fish, responses which could be secondary to elevated plasma lipid (VtG) content, although a direct E2 action on somatotroph function is possible. Plasma T4 concentrations were not affected by E2 treatment, but plasma T3 concentrations were significantly lower than in controls 1 week after implantation when plasma E2 concentrations were the highest; this is in support of the hypothesis that E2 has a suppressive action on T3 production. [source]


Effects of Heat Pretreatment on Lipid and Pigments of Freeze-Dried Spinach

JOURNAL OF FOOD SCIENCE, Issue 8 2001
E. Cho
ABSTRACT: Heat pretreatment resulted in decreases in drying yield and glycolipids (GL) and an increase in neutral lipids (NL). Triacylglycerol and free sterols in NL and sterylglycosides and monogalactosyldiglycerides in GL were more stable during heat pretreatment. Phosphatidylglycerol, phosphatidylethanolamine, and phosphatidic acid among phospholipid subclasses were more susceptible. There was no large difference in fatty-acid composition of spinach lipids by heat pretreatment. However, a significant decrease in linolenic acid and increases in oleic and hexadecenoic acids were observed in NL. Contents of chlorophyll, lutein, and ,-carotene in spinach decreased by heat pretreatment, with the least decrease in lutein. [source]


CARS microscopy of lipid stores in yeast: the impact of nutritional state and genetic background

JOURNAL OF RAMAN SPECTROSCOPY, Issue 7 2009
Christian Brackmann
Abstract We have developed a protocol for sub-micrometer resolved and chemically specific imaging of lipid storage in vivo employing coherent anti-Stokes Raman scattering (CARS) microscopy of one of the most important model organisms Saccharomyces cerevisiae,the yeast cell. By probing the carbon,hydrogen vibration using the nonlinear process of CARS, lipid droplets in the yeast cells clearly appear, as confirmed by comparative studies on relevant labeled organelles using two-photon fluorescence microscopy. From the images, unique quantitative data can be deduced with high three-dimensional resolution, such as the volume, shape, number, and intracellular location of the neutral lipid stores. We exemplify the strength and usability of the method for two cases: the impact on lipid storage of the nutritional condition (starvation and type of carbon source available) as well as of genetic modification of two fundamental metabolic regulation pathways involving carbohydrate and lipid storage (BCY1 and DGA1, LRO1, ARE1/2 deletions), respectively. While the impact of carbon source on the total cellular lipid volume was minimal, long-term starvation induces a significant accumulation of lipid droplets. We also confirm that the lipid-storage-deficient mutant is indeed unable to synthesize lipid droplets, and that the inability of the bcy1 -mutant to store carbohydrates is compensated by a two-fold increase in stored neutral lipids. We note that there is a significant cell-to-cell variability in neutral lipid storage in general, i.e. that there is a correspondence to the noise found for gene expression also in lipidomics. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Ethanol Self-Administration and Alterations in the Livers of the Cynomolgus Monkey, Macaca fascicularis

ALCOHOLISM, Issue 1 2007
Priscilla Ivester
Background: Most of the studies of alcoholic liver disease use models in which animals undergo involuntary administration of high amounts of ethanol and consume diets that are often high in polyunsaturated fatty acids. The objectives of this study were (1) to evaluate whether cynomolgus monkeys (Macaca fascicularis) drinking ethanol voluntarily and consuming a diet with moderate amounts of lipid would demonstrate any indices of alcoholic liver disease past the fatty liver stage and (2) to determine whether these alterations were accompanied by oxidative stress. Methods: Six adult male and 6 adult female cynomolgus monkeys were allowed to consume ethanol voluntarily for 18 to 19 months. Additional monkeys were maintained on the same consumption protocol, but were not provided with ethanol. During the course of the study, liver biopsy samples were monitored for lipid deposition and inflammation, serum for levels of liver enzymes, and urine for concentrations of the isoprostane (IsoP) metabolite, 2,3-dinor-5,6-dihydro-15-F2t -IsoP, a biomarker for oxidative stress. Liver mitochondria were monitored for respiratory control and liver for concentrations of neutral lipids, adenine nucleotides, esterified F2 isoprostanes, oxidized proteins, 4-hydroxynonenal (HNE)-protein adducts, and protein levels of cytochrome P-450 2E1 and 3A4. Results: Ethanol consumption ranged from 0.9 to 4.05 g/kg/d over the period of the study. Serum levels of aspartate amino transferase were elevated in heavy-consuming animals compared with those in ethanol-naïve or moderate drinkers. Many of the ethanol consumers developed fatty liver and most showed loci of inflammation. Both hepatic energy charge and phosphorylation potential were decreased and NADH-linked respiration was slightly, but significantly depressed in coupled mitochondria as a result of heavy ethanol consumption. The urinary concentrations of 2,3-dinor-5,6-dihydro-15-F2t -IsoP increased as high as 33-fold over that observed in ethanol-abstinent animals. Liver cytochrome P-450 2E1 concentrations increased in ethanol consumers, but there were no ethanol-elicited increases in hepatic concentrations of the esterified F2 isoprostanes, oxidized proteins, or HNE-protein adducts. Conclusion: Our studies show that cynomolgus monkeys undergoing voluntary ethanol consumption for 1.5 years exhibit many of the features observed in the early stages of human alcoholic liver disease. Ethanol-elicited fatty liver, inflammation, and elevated serum aspartate amino transferase were evident with a diet that contained modest amounts of polyunsaturated lipids. The dramatic increases in urinary IsoP demonstrated that the animals were being subjected to significant oxidative stress that correlated with their level of ethanol consumption. [source]


Influence of environmental temperature on composition of lipids in edible flesh of rainbow trout (Oncorhynchus mykiss)

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2003
Antonella Calabretti
Abstract The adaptative changes in the fatty acid composition of the main lipid classes in rainbow trout (Oncorhynchus mykiss) edible flesh in response to environmental variation in water temperature were investigated. The research was carried out on intensively farmed trout sampled at different times of the year. Neutral lipids (NL), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were separated using flash chromatography. Compared with summer acclimatisation, a decrease in neutral lipids of about 19% was observed in winter, accompanied by increases in phosphatidylethanolamine and phosphatidylcholine of about 41 and 29%, respectively. The metabolic adjustment in cold adaptation caused an increase in the levels of unsaturated fatty acids and monoenes of the oleic acid ,9 family and an increase in the levels of unsaturated fatty acids of the linoleic acid ,3 family. At the same time a reduction in the levels of saturated and monounsaturated fatty acids of the oleic acid ,9 family was observed. This pattern turned out to be particularly evident in phosphatidylcholine. The net result of these changes in composition was a significant increase in the polyunsaturated/saturated and polyunsaturated/monoenic fatty acid ratios in the edible flesh. Copyright © 2003 Society of Chemical Industry [source]


Role of Lung Surfactant in Respiratory Disease: Current Knowledge in Large Animal Medicine

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2009
U. Christmann
Lung surfactant is produced by type II alveolar cells as a mixture of phospholipids, surfactant proteins, and neutral lipids. Surfactant lowers alveolar surface tension and is crucial for the prevention of alveolar collapse. In addition, surfactant contributes to smaller airway patency and improves mucociliary clearance. Surfactant-specific proteins are part of the innate immune defense mechanisms of the lung. Lung surfactant alterations have been described in a number of respiratory diseases. Surfactant deficiency (quantitative deficit of surfactant) in premature animals causes neonatal respiratory distress syndrome. Surfactant dysfunction (qualitative changes in surfactant) has been implicated in the pathophysiology of acute respiratory distress syndrome and asthma. Analysis of surfactant from amniotic fluid allows assessment of fetal lung maturity (FLM) in the human fetus and exogenous surfactant replacement therapy is part of the standard care in premature human infants. In contrast to human medicine, use and success of FLM testing or surfactant replacement therapy remain limited in veterinary medicine. Lung surfactant has been studied in large animal models of human disease. However, only a few reports exist on lung surfactant alterations in naturally occurring respiratory disease in large animals. This article gives a general review on the role of lung surfactant in respiratory disease followed by an overview of our current knowledge on surfactant in large animal veterinary medicine. [source]


Accumulation of cholesterol in the lesions of focal segmental glomerulosclerosis

NEPHROLOGY, Issue 5 2003
HYUN SOON LEE
SUMMARY: Intraglomerular deposition of low-density lipoprotein (LDL) and oxidized LDL has been described in various human glomerular diseases. Yet it is not clear whether esterified cholesterol (EC) and unesterified cholesterol (UC) carried in LDL are mobilized from deposited LDL particles or accumulate in the diseased human glomeruli, particularly in the segmentally sclerotic lesions. To address this issue, frozen sections of renal biopsies were first immunostained to localize apolipoprotein B (apo B) and then oil red O (ORO) stained to colocalize neutral lipids. By using 124 ORO-positive biopsies and nine ORO-negative ones, UC was visualized directly with filipin staining, and EC was visualized after its enzymatic hydrolysis and staining with filipin. Seventy-seven biopsies (58%) showed filipin staining of accumulated EC and/or UC in the glomeruli. Of these, 11 showed heavy filipin staining for both EC and UC in the segmentally sclerotic lesions. In a group with UC deposits in the sclerotic segments, the percentage of the glomeruli affected by sclerosis and the intensity of filipin fluorescence for UC were significantly higher than biopsies with only mesangial UC deposits. Most filipin-positive biopsies showed apo B staining mainly in the mesangium. Yet in the sclerotic segments, apo B staining was rarely noted. Accumulated apo B-stained lipoprotein was not coincident with ORO-stained lipid in the diseased glomeruli. These results suggest that both EC and UC accumulate in the sclerotic glomerular segments as the glomerular lesions are advanced, and that these EC and UC appear to be derived from altered LDL with progressive loss of apo B. [source]


Change in sugar, sterol and fatty acid composition in banana meristems caused by sucrose-induced acclimation and its effects on cryopreservation

PHYSIOLOGIA PLANTARUM, Issue 1 2006
Guo-Yu Zhu
To understand the mechanisms of sucrose-induced acclimation in relation to plant cryopreservation, sugars, sterols, fatty acids of different lipid fractions (neutral lipids, glycolipids and sphingolipids and phospholipids), as well as free fatty acids were analyzed in proliferating meristem cultures of different banana varieties. The four banana varieties that were selected show different post-thaw shoot regeneration rates (0,53.4%). All mentioned parameters were analyzed using (1) control meristems that were cultured on a normal sucrose concentration (0.09 M), which resulted in low survival after cryopreservation; and (2) 2-week sucrose precultured meristems (0.4 M). This sucrose preculture, essential for regeneration after cryopreservation, resulted in a significant increase of each of seven sugars detected. The ratio of stigmasterol/sitosterol (St/Si) in sucrose-pretreated meristems significantly increased. The sucrose pretreatment also resulted in a significant increase of total fatty acid content of the neutral lipid fraction and of the glycolipid and sphingolipid fraction, as well as the total free fatty acid content. The individual fatty acid content of the phospholipids was differently changed by the sucrose pretreatment for the given varieties studied. In most cases, sucrose pretreatment resulted in an increase of the double bond index (DBI) in the neutral lipids and a decrease of DBI in the glycolipids and sphingolipids, in phospholipids as well as in free fatty acids. Principal component analysis of all collected data revealed that (1) for the control material, sucrose and total sugar contents were closely linked to the post-thaw shoot regeneration, suggesting that sucrose and total sugar may be main limiting factors to survive cryopreservation; (2) accumulation of large quantities of sugars (glucose, fructose, sucrose and total sugar) in sucrose-pretreated material cannot explain the differences in survival after cryopreservation of the four banana varieties. We assume that a minimal amount of sugars is needed in meristem cultures to survive cryopreservation. Still, other limiting factors do influence the survival following the sucrose pretreatment. We observed that the parameters which are closely linked to the post-thaw shoot regeneration are a minimal change in the ratios of St/Si, the minimal change of the DBI of phospholipids and free fatty acids, as well as linoleic acid content (C18:2); and (3) inositol, raffinose, myristic acid (C14:0) and oleic acid (C18:1) were present in small quantities; however, they could be correlated to survival after cryopreservation, suggesting that they may be also involved in cryopreservation process. [source]


The synthesis and accumulation of stearidonic acid in transgenic plants: a novel source of ,heart-healthy' omega-3 fatty acids

PLANT BIOTECHNOLOGY JOURNAL, Issue 7 2009
Noemí Ruiz-López
Summary Dietary omega-3 polyunsaturated fatty acids have a proven role in reducing the risk of cardiovascular disease and precursor disease states such as metabolic syndrome. Although most studies have focussed on the predominant omega-3 fatty acids found in fish oils (eicosapentaenoic acid and docosahexaenoic acid), recent evidence suggests similar health benefits from their common precursor, stearidonic acid. Stearidonic acid is a ,6-unsaturated C18 omega-3 fatty acid present in a few plant species (mainly the Boraginaceae and Primulaceae) reflecting the general absence of ,6-desaturation from higher plants. Using a ,6-desaturase from Primula vialii, we generated transgenic Arabidopsis and linseed lines accumulating stearidonic acid in their seed lipids. Significantly, the P. vialii,6-desaturase specifically only utilises ,-linolenic acid as a substrate, resulting in the accumulation of stearidonic acid but not omega-6 ,-linolenic acid. Detailed lipid analysis revealed the accumulation of stearidonic acid in neutral lipids such as triacylglycerol but an absence from the acyl-CoA pool. In the case of linseed, the achieved levels of stearidonic acid (13.4% of triacylglycerols) are very similar to those found in the sole natural commercial plant source (Echium spp.) or transgenic soybean oil. However, both those latter oils contain ,-linolenic acid, which is not normally present in fish oils and considered undesirable for heart-healthy applications. By contrast, the stearidonic acid-enriched linseed oil is essentially devoid of this fatty acid. Moreover, the overall omega-3/omega-6 ratio for this modified linseed oil is also significantly higher. Thus, this nutritionally enhanced linseed oil may have superior health-beneficial properties. [source]


Phosphonium labeling for increasing metabolomic coverage of neutral lipids using electrospray ionization mass spectrometry,

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 12 2009
Hin-Koon Woo
Mass spectrometry has become an indispensable tool for the global study of metabolites (metabolomics), primarily using electrospray ionization mass spectrometry (ESI-MS). However, many important classes of molecules such as neutral lipids do not ionize well by ESI and go undetected. Chemical derivatization of metabolites can enhance ionization for increased sensitivity and metabolomic coverage. Here we describe the use of tris(2,4,6,-trimethoxyphenyl)phosphonium acetic acid (TMPP-AA) to improve liquid chromatography (LC)/ESI-MS detection of hydroxylated metabolites (i.e. lipids) from serum extracts. Cholesterol which is not normally detected from serum using ESI is observed with attomole sensitivity. This approach was applied to identify four endogenous lipids (hexadecanoyl-sn-glycerol, dihydrotachysterol, octadecanol, and alpha-tocopherol) from human serum. Overall, this approach extends the types of metabolites which can be detected using standard ESI-MS instrumentation and demonstrates the potential for targeted metabolomics analysis. Published in 2009 by John Wiley & Sons, Ltd. [source]


A simplified protein precipitation/mixed-mode cation-exchange solid-phase extraction, followed by high-speed liquid chromatography/mass spectrometry, for the determination of a basic drug in human plasma

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2006
Y.-J. Xue
A simplified protein precipitation/mixed-mode cation-exchange solid-phase extraction (PPT/SPE) procedure has been investigated. A mixture of acetonitrile and methanol along with formic acid was used to precipitate plasma proteins prior to selectively extracting the basic drug. After vortexing and centrifugation, the supernatants were directly loaded onto an unconditioned Oasis® MCX µElution 96-well extraction plate, where the protonated drug was retained on the negatively charged sorbent while interfering neutral lipids, steroids or other endogenous materials were washed away. Normal wash steps were deemed unnecessary and not used before sample elution. The sample extracts were analyzed under both conventional and high-speed liquid chromatography/tandem mass spectrometry (LC/MS/MS) conditions to examine the feasibility of the PPT/SPE procedure for human plasma sample clean-up. For the conventional LC/MS/MS method, chromatographic separation was achieved on a C18, 2.1,×,50,mm column with gradient elution (k,,=,5.5). The mobile phase contained 0.1% formic acid in water and 0.1% formic acid in acetonitrile. For the high-speed LC/MS/MS method, chromatographic separation was achieved on a C18, 2.1,×,10,mm guard column with gradient elution (k,,=,2.2, Rt,=,0.26,min). The mobile phase contained 0.1% formic acid in water and 0.001% trifluoroacetic acid in acetonitrile. Detection for both conventional and high-speed LC/MS/MS methods was by positive ion electrospray tandem mass spectrometry on a ThermoElectron Finnigan TSQ Quantum Ultra, where enhanced resolution (RP 2000; 0.2,amu) was used for high-speed LC/MS/MS. The standard curve, ranging from 0.5 to 100,ng/mL, was fitted to a 1/x weighted quadratic regression model. This combined PPT/SPE procedure effectively eliminated time-consuming sorbent conditioning and wash steps, which are essential for a conventional mixed-mode SPE procedure, but retained the advantages of both PPT (removal of plasma proteins) and mixed-mode SPE (analyte selectivity). The validation results demonstrated that this PPT/SPE procedure was well suited for both conventional and high-speed LC/MS/MS analyses. In comparison with a conventional mixed-mode SPE procedure, the simplified PPT/SPE process provided comparable sample extract purity. This simple sample clean-up procedure can be applied to other basic compounds with minor modifications of PPT solvents. Copyright © 2006 John Wiley & Sons, Ltd. [source]


The use of alternative diets to culture juvenile cuttlefish, Sepia officinalis: effects on growth and lipid composition

AQUACULTURE NUTRITION, Issue 3 2010
A. FERREIRA
Abstract The effects of feeding three natural frozen diets, grass shrimp (Palaemonetes sp.), crayfish (Procambarus clarkii) and fish (Sardina pilchardus) and two semi-humid artificial diets (based on fish or shrimp powder) to the cuttlefish, Sepia officinalis, were analysed. Growth rate and feeding rate [FR; % body weight (BW) day,1] and food conversions (FC, %) were determined. Cuttlefish fed shrimp grew larger (3.8% BW day,1) and had the highest FC, followed by those fed crayfish, and sardine. The highest FR was obtained for cuttlefish fed crayfish (10.5% BW day,1). Although both artificial diets were accepted, none produced growth. Digestive gland-to-body weight ratio (DG/BW ratio) was calculated for animals fed each diet. A positive correlation (r = 0.94) between cuttlefish ingestion FR and DG weight was obtained. Mortality occurred mainly during the last week, and some cannibalism occurred among cuttlefish fed artificial diets. Finally, lipid composition of diets, DG and mantle of each group were analysed. Sardine diet was characterized by high levels of triacylglycerol (TG), whereas the main difference between shrimp and crayfish was the higher n -3/n -6 ratio found in shrimp. Changes in the lipid composition of DG were related to diet, but did not correlate with growth data. A strong loss of TG in the DG of artificial diets groups was notable. No differences in mantle lipid composition among the natural diets were found, but artificial diet groups showed higher contents of neutral lipids in their mantle respect to natural diets. According to results obtained, crayfish (P. clarkii) could be used as an alternative prey for rearing S. officinalis compared with shrimp. Artificial diets showed the worst effects in growth and mortality as well as the stronger influence on DG and mantle lipid composition of cuttlefish. [source]


Influences of dietary fatty acid profile on growth, body composition and blood chemistry in juvenile fat cod (Hexagrammos otakii Jordan et Starks)

AQUACULTURE NUTRITION, Issue 1 2009
S.-M. LEE
Abstract This study was conducted to investigate the influence of dietary lipid source and n-3 highly unsaturated fatty acids (n-3 HUFA) level on growth, body composition and blood chemistry of juvenile fat cod. Triplicate groups of fish (13.2 ± 0.54 g) were fed the diets containing different n-3 HUFA levels (0,30 g kg,1) adjusted by either lauric acid or different proportions of corn oil, linseed oil and squid liver oil at 100 g kg,1 of total lipid level. Survival was not affected by dietary fatty acids composition. Weight gain, feed efficiency and protein efficiency ratio (PER) of fish fed the diets containing squid liver oil were significantly (P < 0.05) higher than those fed the diets containing lauric acid, corn oil or linseed oil as the sole lipid source. Weight gain, feed efficiency and PER of fish increased with increasing dietary n-3 HUFA level up to 12,16 g kg,1, but the values decreased in fish fed the diet containing 30 g kg,1 n-3 HUFA. The result of second-order polynomial regression showed that the maximum weight gain and feed efficiency could be attained at 17 g kg,1 n-3 HUFA. Plasma protein, glucose and cholesterol contents were not affected by dietary fatty acids composition. However, plasma triglyceride content in fish fed the diet containing lauric acid as the sole lipid source was significantly (P < 0.05) lower than that of fish fed the other diets. Lipid content of fish fed the diets containing each of lauric acid or corn oil was lower than that of fish fed the diets containing linseed oil or squid liver oil only. Fatty acid composition of polar and neutral lipid fractions in the whole body of fat cod fed the diets containing various levels of n-3 HUFA were reflected by dietary fatty acids compositions. The contents of n-3 HUFA in polar and neutral lipids of fish increased with an increase in dietary n-3 HUFA level. These results indicate that dietary n-3 HUFA are essential and the diet containing 12,17 g kg,1 n-3 HUFA is optimal for growth and efficient feed utilization of juvenile fat cod, however, excessive n-3 HUFA supplement may impair the growth of fish. [source]


Lipid characterization of both wild and cultured eggs of cuttlefish (Sepia officinalis L.) throughout the embryonic development

AQUACULTURE NUTRITION, Issue 1 2009
A.V. SYKES
Abstract The present work reports a characterization of mean wet weight and moisture, the lipid class and fatty acid (FA) composition from the total lipids (TL), of both culture and wild eggs of the cuttlefish, Sepia officinalis, throughout the embryonic development. Additionally, reproductive data, such as the number of spawnings, number and mean weight of eggs and duration of spawning period of cultured cuttlefish is provided. Both types of eggs were similar in mean wet weight, moisture content, TL content and lipid composition throughout embryonic development. Females from the cultured group spawned 13 times and laid 8654 eggs in 64 days, with a mean weight of 0.607 ± 0.179 g. A sex ratio of 1.57 (11, for 7,) promoted an individual fecundity of 787 eggs/, (the biggest until now on our culture facilities), which might be related to increased bottom areas. The TL increased with day/stage of embryonic development (P < 0.05) only in the cultured egg group. However, no differences were found on TL between culture and wild eggs at the same day/stage (P > 0.05). Eggs displayed predominant levels of phosphatidylcholine, phosphatidylethanolamine (PE), cholesterol and triacylglycerol at the end of embryonic development. Polar and neutral lipids of both eggs groups remained consistently proportional (,50% for each lipid fraction) and a significant increase (P < 0.05) was observed in phosphatidylserine, PE and free FA throughout the embryonic development. In either egg type and day, 16:0, 18:0, 20:5n-3 and 22:6n-3 accounted for approximately 70 g Kg,1 of all FA and saturated and n-3 totals seemed to have the same proportion in the cuttlefish eggs. The present results suggest that lipids are not used as energetic substrate but as structural components in cuttlefish egg. [source]


Comparison of dietary phospholipids and neutral lipids: effects on gut, liver and pancreas histology in Atlantic cod (Gadus morha L.) larvae

AQUACULTURE NUTRITION, Issue 1 2009
P.-A. WOLD
Abstract The aim of the present study was to compare effects of dietary n-3 highly unsaturated fatty acids (HUFA) being incorporated in the phospholipid (PL) or in the neutral lipid (NL) fraction of the larval feed, on larval growth and histology of digestive organs in Atlantic cod (Gadus morhua L.) larvae. Three isoproteic and isolipidic diets, labelled according to the percentage of n-3 docosahexaenoic acid and eicosapentaenoic acid contained in NL1 or in PL1 and PL3 of the diets, were fed to cod larvae from 17 days post hatching (dph) to 45 dph. In the liver, hepatocytes and their nuclei were smaller in NL1 larvae compared with the PL larvae; the mitochondrial membrane structures were less dense and the amount of lipids observed in the liver was significantly higher in NL1 larvae compared with the PL3 larvae. The liver and gut size was related to larval size, with no differences between the larval groups. The results demonstrated that the essential fatty acids were more beneficial for cod larvae when they were incorporated in the dietary polar PL rather than in the NL, and that the n-3 HUFA requirements in cod larvae is possibly higher than that in the PL1 diet. [source]