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Sample records for cholesterol constrains glycolipid

  1. A fluorescent glycolipid-binding peptide probe traces cholesterol dependent microdomain-derived trafficking pathways.

    Directory of Open Access Journals (Sweden)

    Steffen Steinert

    Full Text Available BACKGROUND: The uptake and intracellular trafficking of sphingolipids, which self-associate into plasma membrane microdomains, is associated with many pathological conditions, including viral and toxin infection, lipid storage disease, and neurodegenerative disease. However, the means available to label the trafficking pathways of sphingolipids in live cells are extremely limited. In order to address this problem, we have developed an exogenous, non-toxic probe consisting of a 25-amino acid sphingolipid binding domain, the SBD, derived from the amyloid peptide Abeta, and conjugated by a neutral linker with an organic fluorophore. The current work presents the characterization of the sphingolipid binding and live cell trafficking of this novel probe, the SBD peptide. SBD was the name given to a motif originally recognized by Fantini et al in a number of glycolipid-associated proteins, and was proposed to interact with sphingolipids in membrane microdomains. METHODOLOGY/PRINCIPAL FINDINGS: In accordance with Fantini's model, optimal SBD binding to membranes depends on the presence of sphingolipids and cholesterol. In synthetic membrane binding assays, SBD interacts preferentially with raft-like lipid mixtures containing sphingomyelin, cholesterol, and complex gangliosides in a pH-dependent manner, but is less glycolipid-specific than Cholera toxin B (CtxB. Using quantitative time-course colocalization in live cells, we show that the uptake and intracellular trafficking route of SBD is unlike that of either the non-raft marker Transferrin or the raft markers CtxB and Flotillin2-GFP. However, SBD traverses an endolysosomal route that partially intersects with raft-associated pathways, with a major portion being diverted at a late time point to rab11-positive recycling endosomes. Trafficking of SBD to acidified compartments is strongly disrupted by cholesterol perturbations, consistent with the regulation of sphingolipid trafficking by cholesterol

  2. Cholesterol, sphingolipids, and glycolipids: What do we know about their role in raft-like membranes?

    DEFF Research Database (Denmark)

    Rog, T.; Vattulainen, I.

    2014-01-01

    Lipids rafts are considered to be functional nanoscale membrane domains enriched in cholesterol and sphingolipids, characteristic in particular of the external leaflet of cell membranes. Lipids, together with membrane-associated proteins, are therefore considered to form nanoscale units with pote...

  3. Glycolipid binding preferences of Shiga toxin variants.

    Directory of Open Access Journals (Sweden)

    Sayali S Karve

    Full Text Available The major virulence factor of Shiga toxin producing E. coli, is Shiga toxin (Stx, an AB5 toxin that consists of a ribosomal RNA-cleaving A-subunit surrounded by a pentamer of receptor-binding B subunits. The two major isoforms, Stx1 and Stx2, and Stx2 variants (Stx2a-h significantly differ in toxicity. The exact reason for this toxicity difference is unknown, however different receptor binding preferences are speculated to play a role. Previous studies used enzyme linked immunosorbent assay (ELISA to study binding of Stx1 and Stx2a toxoids to glycolipid receptors. Here, we studied binding of holotoxin and B-subunits of Stx1, Stx2a, Stx2b, Stx2c and Stx2d to glycolipid receptors globotriaosylceramide (Gb3 and globotetraosylceramide (Gb4 in the presence of cell membrane components such as phosphatidylcholine (PC, cholesterol (Ch and other neutral glycolipids. In the absence of PC and Ch, holotoxins of Stx2 variants bound to mixtures of Gb3 with other glycolipids but not to Gb3 or Gb4 alone. Binding of all Stx holotoxins significantly increased in the presence of PC and Ch. Previously, Stx2a has been shown to form a less stable B-pentamer compared to Stx1. However, its effect on glycolipid receptor binding is unknown. In this study, we showed that even in the absence of the A-subunit, the B-subunits of both Stx1 and Stx2a were able to bind to the glycolipids and the more stable B-pentamer formed by Stx1 bound better than the less stable pentamer of Stx2a. B-subunit mutant of Stx1 L41Q, which shows similar stability as Stx2a B-subunits, lacked glycolipid binding, suggesting that pentamerization is more critical for binding of Stx1 than Stx2a.

  4. Stem cell glycolipids.

    Science.gov (United States)

    Yanagisawa, Makoto

    2011-09-01

    Glycolipids are compounds containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety. Because of their expression patterns and the intracellular localization patterns, glycolipids, including stage-specific embryonic antigens (SSEA-3, SSEA-4, and possibly SSEA-1) and gangliosides (e.g., GD3, GD2, and A2B5 antigens), have been used as marker molecules of stem cells. In this review, I will introduce glycolipids expressed in pluripotent stem cells (embryonic stem cells, induced pluripotent stem cells, very small embryonic-like stem cells, amniotic stem cells, and multilineage-differentiating stress enduring cells), multipotent stem cells (neural stem cells, mesenchymal stem cells, fetal liver multipotent progenitor cells, and hematopoietic stem cells), and cancer stem cells (brain cancer stem cells and breast cancer stem cells), and discuss their availability as biomarkers for identifying and isolating stem cells. PMID:21161592

  5. Glycolipids of Saccharomyces cerevisiae Cell

    Directory of Open Access Journals (Sweden)

    Renuka Malhotra

    2005-01-01

    Full Text Available Total lipids of Saccharomyces cerevisiae were isolated by chloroform and methanol (2:1. Glycolipids were separated from total lipids by silicic acid chromatography. Glycolipid’s constituent sugars and fatty acids were analyzed by using Gas Liquid Chromatography. Galactose was the prominent sugar followed by mannose. Relative concentrations of fucose, mannose, galactose and glucose in the glycolipid were 5.3, 35.2, 55.1 and 4.2%. 16:0, 18:0, 18:1, 18:2 and 18:3 were the major fatty acids of the total glycolipids. Oleic acid was the dominating fatty acid followed by linoliec acid. They were separated into different fractions by using DEAE-Sephadex ion exchange chromatography. Glycolipids were fractionated and identified as cerebrosides, ceramide polyhexosides, sulfatides, monoglucosyldiglycerides and diglucosyldiglycerides. Ceramide polyhexosides were present in higher concentration as compared to other fractions.

  6. Glycolipid biosynthesis in cyanobacteria

    International Nuclear Information System (INIS)

    The biosynthesis of monogalactosyldiacyl-glycerol (MGDG) was studied in five different cyanobacteria. Previous work has shown Anabaena variabilis to synthesize both MGDG and monoglucosyl-diacylglycerol (MG1cDG) with MG1cDG being the precursor of MGDG. They have examined four other cyanobacteria to determine if a similar relationship exists. The cyanobacteria studied were Anabaena variabilis, Chlorogloeopsis sp., Schizothrix calcicola, Anacystis nidulans, and Anacystis marina. Each were grown in liquid culture and lipids were labeled with 14C]CO2 for 20 min., 1.0 hr, 1.0 hr + 10 hr chase. Glycolipids were analyzed by initial separation of MGDG and MG1cDG by TLC followed by further analysis by HPLC. Complete separation of molecular species was obtained isocratically on an ODS column. All of the cyanobacteria labeled 16-C and 18-C fatty acids except for A. marina which labeled only 14-C and 16-C fatty acids. Desaturation of the fatty acids could be observed in the 1.0 hr and chase experiments. All were capable of labeling both MG1cDG and MGDG with the precursor-product relationship being observed. There does not appear to be a direct relationship between the epimerization of the sugar moiety and fatty acid desaturation

  7. Sterol-modulated glycolipid sorting occurs in niemann-pick C1 late endosomes.

    Science.gov (United States)

    Zhang, M; Dwyer, N K; Neufeld, E B; Love, D C; Cooney, A; Comly, M; Patel, S; Watari, H; Strauss, J F; Pentchev, P G; Hanover, J A; Blanchette-Mackie, E J

    2001-02-01

    The Niemann-Pick C1 (NPC1) protein and endocytosed low density lipoprotein (LDL)-derived cholesterol were shown to enrich separate subsets of vesicles containing lysosomal associated membrane protein 2. Localization of Rab7 in the NPC1-containing vesicles and enrichment of lysosomal hydrolases in the cholesterol-containing vesicles confirmed that these organelles were late endosomes and lysosomes, respectively. Lysobisphosphatidic acid, a lipid marker of the late endosomal pathway, was found in the cholesterol-enriched lysosomes. Recruitment of NPC1 to Rab7 compartments was stimulated by cellular uptake of cholesterol. The NPC1 compartment was shown to be enriched in glycolipids, and internalization of GalNAcbeta1-4[NeuAcalpha2-3]Galbeta1-4Glcbeta1-1'-ceramide (G(M2)) into endocytic vesicles depends on the presence of NPC1 protein. The glycolipid profiles of the NPC1 compartment could be modulated by LDL uptake and accumulation of lysosomal cholesterol. Expression in cells of biologically active NPC1 protein fused to green fluorescent protein revealed rapidly moving and flexible tubular extensions emanating from the NPC1-containing vesicles. We conclude that the NPC1 compartment is a dynamic, sterol-modulated sorting organelle involved in the trafficking of plasma membrane-derived glycolipids as well as plasma membrane and endocytosed LDL cholesterol. PMID:11032830

  8. What's Cholesterol?

    Science.gov (United States)

    ... Skiing, Snowboarding, Skating Crushes What's a Booger? What's Cholesterol? KidsHealth > For Kids > What's Cholesterol? Print A A ... thing for food to be low in it? Cholesterol and Your Body Cholesterol (say: kuh-LES-tuh- ...

  9. Dehydration resistance of liposomes containing trehalose glycolipids

    Science.gov (United States)

    Nyberg, Kendra; Goulding, Morgan; Parthasarathy, Raghuveer

    2010-03-01

    The pathogen, Mycobacterium tuberculosis, has an unusual outer membrane containing trehalose glycolipids that may contribute to its ability to survive freezing and dehydration. Based on our recent discovery that trehalose glycolipids confer dehydration resistance to supported lipid monolayers (Biophys. J. 94: 4718-4724 (2008); Langmuir 25: 5193-5198, (2009)), we hypothesized that liposomes containing synthetic trehalose glycolipids may be dehydration-resistant as well. To test this, we measured the leakage of encapsulated fluorophores and larger macromolecular cargo from such liposomes subject to freeze drying. Both leakage assays and size measurements show that the liposomes are dehydration-resistant. In addition to demonstrating a possibly technologically useful encapsulation platform, our results corroborate the view that encapsulation in a trehalose-glycolipid-rich membrane is a biophysically viable route to protection of mycobacteria from environmental stresses.

  10. About Cholesterol

    Science.gov (United States)

    ... High Blood Pressure Tools & Resources Stroke More About Cholesterol Updated:Aug 10,2016 It may surprise you ... our bodies to keep us healthy. What is cholesterol and where does it come from? Cholesterol is ...

  11. Natural surfactants used in cosmetics: glycolipids.

    Science.gov (United States)

    Lourith, N; Kanlayavattanakul, M

    2009-08-01

    Cosmetic surfactant performs detergency, wetting, emulsifying, solubilizing, dispersing and foaming effects. Adverse reactions of chemical synthesis surfactant have an effect on environment and humans, particularly severe in long term. Biodegradability, low toxicity and ecological acceptability which are the benefits of naturally derived surfactant that promises cosmetic safety are, therefore, highly on demand. Biosurfactant producible from microorganisms exhibiting potential surface properties suitable for cosmetic applications especially incorporate with their biological activities. Sophorolipids, rhamnolipids and mannosylerythritol lipids are the most widely used glycolipids biosurfactant in cosmetics. Literatures and patents relevant to these three glycolipids reviewed were emphasizing on the cosmetic applications including personal care products presenting the cosmetic efficiency, efficacy and economy benefits of glycolipids biosurfactant. PMID:19496839

  12. Cholesterol (image)

    Science.gov (United States)

    Cholesterol is a soft, waxy substance that is present in all parts of the body including the ... and obtained from animal products in the diet. Cholesterol is manufactured in the liver and is needed ...

  13. Production of glycolipid biosurfactants by basidiomycetous yeasts.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2009-05-01

    BSs (biosurfactants) produced by various micro-organisms show unique properties (e.g. mild production conditions, lower toxicity, higher biodegradability and environmental compatibility) compared with chemically synthesized surfactants. The numerous advantages of BSs have prompted applications not only in the food, cosmetic and pharmaceutical industries but also in environmental protection and energy-saving technology. Among BSs, glycolipid types are the most promising, owing to their high productivity from renewable resources and versatile biochemical properties. MELs (mannosylerythritol lipids), which are glycolipid BSs abundantly produced by basidiomycetous yeasts such as strains of Pseudozyma, exhibit not only excellent interfacial properties, but also remarkable differentiation-inducing activities against human leukaemia cells. MELs also show high binding affinity towards different immunoglobulins and lectins. Recently, a cationic liposome bearing MEL has been demonstrated to increase dramatically the efficiency of gene transfection into mammalian cells. These features of BSs should broaden their application in new advanced technologies. In the present review the current status of research and development on glycolipid BSs, especially their production by Pseudozyma yeasts, is described. PMID:19341364

  14. Good vs. Bad Cholesterol

    Science.gov (United States)

    ... Pressure Tools & Resources Stroke More Good vs. Bad Cholesterol Updated:Mar 23,2016 Cholesterol can't dissolve ... test . View an animation of cholesterol . LDL (Bad) Cholesterol LDL cholesterol is considered the “bad” cholesterol because ...

  15. [Advance in glycolipid biosurfactants--mannosylerythritol lipids].

    Science.gov (United States)

    Fan, Linlin; Zhang, Jun; Cai, Jin; Dong, Yachen; Xu, Tengyang; He, Guoqing; Chen, Qihe

    2013-09-01

    Mannosylerythritol lipids (MELs), mainly produced by Ustilago and Pseudozyma, are surface active compounds that belong to the glycolipid class of biosurfactants. MELs have potential application in food, pharmaceutical and cosmetics industries due to their excellent surface activities and other peculiar bioactivities. In recent years, the research field of MELs has regained much attention abroad. However, MELs are rarely studied in China. In this review, the producing microorganisms and production conditions, diverse structures, biochemical properties, structure-function relationship and biosynthetic pathways of MELs are described. Some research problems and prospects are summarized and discussed as well. PMID:24409686

  16. Nitrogen and hydrophosphate affects glycolipids composition in microalgae

    Science.gov (United States)

    Wang, Xin; Shen, Zhouyuan; Miao, Xiaoling

    2016-01-01

    Glycolipids had received increasing attention because of their uses in various industries like cosmetics, pharmaceuticals, food and machinery manufacture. Microalgae were competitive organisms to accumulate metabolic substance. However, using microalgae to produce glycolipid was rare at present. In this study, glycolipid content of Chlorella pyrenoidosa and Synechococcus sp. under different nitrate and hydrophosphate levels were investigated. The highest glycolipid contents of 24.61% for C. pyrenoidosa and 15.37% for Synechococcus sp. were obtained at nitrate absence, which were 17.19% for C. pyrenoidosa and 10.99% for Synechococcus sp. at 0.01 and 0 g L−1 hydrophosphate, respectively. Glycolipid productivities of two microalgae could reach at more than 10.59 mg L−1 d−1. Nitrate absence induced at least 8.5% increase in MGDG, DGDG and SQDG, while hydrophosphate absence resulted in over 21.2% increase in DGDG and over 48.4% increase in SQDG and more than 22.2% decrease in MGDG in two microalgae. Simultaneous nitrate and hydrophosphate limitation could make further improvement of glycolipid accumulation, which was more than 25% for C. pyrenoidosa and 21% for Synechococcus sp. These results suggest that nitrogen and phosphorus limitation or starvation should be an efficient way to improve microalgal glycolipid accumulation. PMID:27440670

  17. Nitrogen and hydrophosphate affects glycolipids composition in microalgae.

    Science.gov (United States)

    Wang, Xin; Shen, Zhouyuan; Miao, Xiaoling

    2016-01-01

    Glycolipids had received increasing attention because of their uses in various industries like cosmetics, pharmaceuticals, food and machinery manufacture. Microalgae were competitive organisms to accumulate metabolic substance. However, using microalgae to produce glycolipid was rare at present. In this study, glycolipid content of Chlorella pyrenoidosa and Synechococcus sp. under different nitrate and hydrophosphate levels were investigated. The highest glycolipid contents of 24.61% for C. pyrenoidosa and 15.37% for Synechococcus sp. were obtained at nitrate absence, which were 17.19% for C. pyrenoidosa and 10.99% for Synechococcus sp. at 0.01 and 0 g L(-1) hydrophosphate, respectively. Glycolipid productivities of two microalgae could reach at more than 10.59 mg L(-1) d(-1). Nitrate absence induced at least 8.5% increase in MGDG, DGDG and SQDG, while hydrophosphate absence resulted in over 21.2% increase in DGDG and over 48.4% increase in SQDG and more than 22.2% decrease in MGDG in two microalgae. Simultaneous nitrate and hydrophosphate limitation could make further improvement of glycolipid accumulation, which was more than 25% for C. pyrenoidosa and 21% for Synechococcus sp. These results suggest that nitrogen and phosphorus limitation or starvation should be an efficient way to improve microalgal glycolipid accumulation. PMID:27440670

  18. Gene therapy: prospects for glycolipid storage diseases.

    Science.gov (United States)

    Gieselmann, Volkmar; Matzner, Ulrich; Klein, Diana; Mansson, Jan Eric; D'Hooge, Rudi; DeDeyn, Peter D; Lüllmann Rauch, Renate; Hartmann, Dieter; Harzer, Klaus

    2003-05-29

    Lysosomal storage diseases comprise a group of about 40 disorders, which in most cases are due to the deficiency of a lysosomal enzyme. Since lysosomal enzymes are involved in the degradation of various compounds, the diseases can be further subdivided according to which pathway is affected. Thus, enzyme deficiencies in the degradation pathway of glycosaminoglycans cause mucopolysaccharidosis, and deficiencies affecting glycopeptides cause glycoproteinosis. In glycolipid storage diseases enzymes are deficient that are involved in the degradation of sphingolipids. Mouse models are available for most of these diseases, and some of these mouse models have been used to study the applicability of in vivo gene therapy. We review the rationale for gene therapy in lysosomal disorders and present data, in particular, about trials in an animal model of metachromatic leukodystrophy. The data of these trials are compared with those obtained with animal models of other lysosomal diseases. PMID:12803926

  19. Glycolipids from the red alga Chondria armata (Kutz.) Okamura

    Digital Repository Service at National Institute of Oceanography (India)

    Al-Fadhli, A.; Wahidullah, S.; DeSouza, L.

    Three distinct fractions containing polar glycolipids (PF1–3) were isolated from the chloroform soluble fraction of crude methanolic extract of red alga Chondria armata (Kütz.) Okamura on gel chromatography over Sephadex LH20. Their structure...

  20. Glycolipid biosurfactants: Potential related biomedical and biotechnological applications.

    Science.gov (United States)

    Inès, Mnif; Dhouha, Ghribi

    2015-10-30

    Glycolipids, consisting of a carbohydrate moiety linked to fatty acids, are microbial surface active compounds produced by various microorganisms. They are characterized by highly structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface respectively. Rhamnolipids, trehalolipids, mannosylerythritol-lipids and cellobiose lipids are among the most popular glycolipids. Moreover, their ability to form pores and destabilize biological membrane permits their use in biomedicine as antibacterial, antifungal and hemolytic agents. Their antiviral and antitumor effects enable their use in pharmaceutic as therapeutic agents. Also, glycolipids can inhibit the bioadhesion of pathogenic bacteria enabling their use as anti-adhesive agents and for disruption of biofilm formation and can be used in cosmetic industry. Moreover, they have great potential application in industry as detergents, wetting agents and for flotation. Furthermore, glycolipids can act at the surface and can modulate enzyme activity permitting the enhancement or the inhibition of the activity of certain enzymes. PMID:26359535

  1. Biosynthesis and skin health applications of antimicrobial glycolipids

    Science.gov (United States)

    Microbial-produced glycolipids (MGLs) such as sophorolipids (SLs), rhamnolipids (RLs), and mannosylerythritol lipids (MELs) are amphiphilic molecules, and thus have been widely explored for use as surfactants/detergents, emulsifiers, and lubricants. One major hindrance to their widespread commercia...

  2. Inhibition of human lymphoproliferative responses by mycobacterial phenolic glycolipids.

    OpenAIRE

    Fournie, J J; Adams, E; Mullins, R J; Basten, A

    1989-01-01

    The effect of mycobacterial phenolic glycolipids from Mycobacterium leprae, M. bovis BCG, and M. kansasii on in vitro proliferative responses by human blood mononuclear cells from healthy BCG vaccinees was investigated. All three phenolic glycolipids inhibited proliferation in a concentration-dependent manner. Inhibition was independent of the stimulus used and involved neither antigen-presenting cells nor antigen-specific CD8+ suppressor T cells. It was concluded that the phenomenon may be a...

  3. Cholesterol Test

    Science.gov (United States)

    ... seen when there is an existing problem like malnutrition , liver disease , or cancer . However there is no ... cholesterol levels include anabolic steroids, beta blockers , epinephrine, oral contraceptives, and vitamin D. ^ Back to top ... Health Professionals Get the Mobile App iTunes | Android | Kindle ...

  4. Cholesterol and Your Child

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth Cholesterol and Your Child KidsHealth > For Parents > Cholesterol and ... child's risk of developing heart disease later. About Cholesterol Cholesterol is a waxy substance produced by the ...

  5. Women and Cholesterol

    Science.gov (United States)

    ... Blood Pressure Tools & Resources Stroke More Women and Cholesterol Updated:Apr 1,2016 The female sex hormone ... Glossary Related Sites Nutrition Center My Life Check Cholesterol • Home • About Cholesterol • Why Cholesterol Matters • Understand Your ...

  6. HDL Cholesterol Test

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? HDL Cholesterol Share this page: Was this page helpful? Also ... HDL; HDL-C Formal name: High-density Lipoprotein Cholesterol Related tests: Cholesterol ; LDL Cholesterol ; Triglycerides ; Lipid Profile ; ...

  7. LDL Cholesterol Test

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? LDL Cholesterol Share this page: Was this page helpful? Also ... LDL; LDL-C Formal name: Low-Density Lipoprotein Cholesterol Related tests: Cholesterol ; HDL Cholesterol ; Triglycerides ; Lipid Profile ; ...

  8. Cholesterol IQ Quiz

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Cholesterol IQ Quiz Updated:Feb 2,2015 Begin the quiz Cholesterol • Home • About Cholesterol Introduction Good vs. Bad Cholesterol ...

  9. Oligosaccharides and glycolipids addition in charged lamellar phases

    International Nuclear Information System (INIS)

    The aim of this work is to study the addition of oligosaccharides and glycolipids in lamellar phases of the cationic surfactant DDAB (di-dodecyl-dimethyl-ammonium bromide). Two steps have been followed: the determination of phases prisms and the thermodynamic interpretation in terms of molecular interactions. In order to characterize these systems, two new experimental small angle scattering methods have been perfected: 1) a neutron scattering contrast variation method which allows to study the adsorption of aqueous solution in bilayers and 2) a capillary concentration gradient method to establish directly and quantitatively the phases diagrams of ternary systems by X rays scattering. It has been pointed out that the oligosaccharides induce a depletion attractive force on the lamellar-lamellar equilibrium of the DDAB when they are excluded of the most concentrated phase. For the two studied glycolipids: 2-O lauroyl-saccharose and N-lauroyl N-nonyl lactitol, the ternary phase diagrams water-DDAB-glycolipid have been established in terms of temperature. Critical points at ambient temperature have been given. The osmotic pressure in concentrated lamellar phases has been measured. It has been shown that glycolipids increase the hydration repulsion at short distance and that the electrostatic repulsion is outstanding and unchanged at high distance if there is at less 1 mole percent of ionic surfactant. In a dilute solution, glycolipids decrease the maximum swelling of lamellar phases, with a competition between the lamellar phase and the micellae dilute phase for water. (O.M.)

  10. Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d`oligosaccharides et de glycolipides dans des phases lamellaires chargees

    Energy Technology Data Exchange (ETDEWEB)

    Ricoul, F

    1997-09-26

    The aim of this work is to study the addition of oligosaccharides and glycolipids in lamellar phases of the cationic surfactant DDAB (di-dodecyl-dimethyl-ammonium bromide). Two steps have been followed: the determination of phases prisms and the thermodynamic interpretation in terms of molecular interactions. In order to characterize these systems, two new experimental small angle scattering methods have been perfected: 1) a neutron scattering contrast variation method which allows to study the adsorption of aqueous solution in bilayers and 2) a capillary concentration gradient method to establish directly and quantitatively the phases diagrams of ternary systems by X rays scattering. It has been pointed out that the oligosaccharides induce a depletion attractive force on the lamellar-lamellar equilibrium of the DDAB when they are excluded of the most concentrated phase. For the two studied glycolipids: 2-O lauroyl-saccharose and N-lauroyl N-nonyl lactitol, the ternary phase diagrams water-DDAB-glycolipid have been established in terms of temperature. Critical points at ambient temperature have been given. The osmotic pressure in concentrated lamellar phases has been measured. It has been shown that glycolipids increase the hydration repulsion at short distance and that the electrostatic repulsion is outstanding and unchanged at high distance if there is at less 1 mole percent of ionic surfactant. In a dilute solution, glycolipids decrease the maximum swelling of lamellar phases, with a competition between the lamellar phase and the micellae dilute phase for water. (O.M.). 165 refs.

  11. Controlled release of diclofenac sodium in glycolipid incorporated micro emulsions.

    Science.gov (United States)

    Premarathne, E P N; Karunaratne, D N; Perera, A D L Chandani

    2016-09-25

    The effect of the glycolipid, hexadecyl-β-d-glucopyranoside, incorporated in microemulsions (ME(1)) towards the enhancement of skin absorption and skin permeation of Diclofenac sodium (DS(2)) was evaluated. A Franz diffusion cell with a piece of pig's ear epidermis indicated that the optimized ME formulation with glycolipid (0.05wt%) exhibited significantly higher permeability than the conventional formulations. The releasing profiles of DS from ME formulations exhibited first order release kinetics resembling a diffusion controlled release model for the first 8h. Incorporating hexadecyl-β-D glucopyranoside in ME formulations shows significant potential as a delivery vehicle in the cosmetics and pharmaceutical industry. PMID:27477103

  12. What Is Cholesterol?

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Cholesterol KidsHealth > For Teens > Cholesterol Print A A A ... High Cholesterol? en español ¿Qué es el colesterol? Cholesterol Is a Fat in the Blood Cholesterol (kuh- ...

  13. Isolation and screening of glycolipid biosurfactant producers from sugarcane.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Hirose, Naoto; Kitamoto, Dai

    2012-01-01

    Forty-three fungal producers for glycolipid biosurfactants, mannosylerythritol lipids (MELs), were isolated from leaves and smuts of sugarcane plants. These isolates produced MELs with sugarcane juice as nutrient source. The strains were taxonomically categorized into the genera Pseudozyma and Ustilago on the basis of partial sequences of the ribosomal RNA gene. PMID:22972331

  14. Production of microbial glycolipid biosurfactants and their antimicrobial activity

    Science.gov (United States)

    Microbial glycolipids produced by bacteria or yeast as secondary metabolites, such as sophorolipids (SLs), rhamnolipids (RLs) and mannosylerythritol lipids (MELs) are “green” biosurfactants desirable in a bioeconomy. High cost of production is a major hurdle toward widespread commercial use of bios...

  15. Cholesterol and lifestyle

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000099.htm Cholesterol and lifestyle To use the sharing features on ... Stroke Serious heart or blood vessel disease Your Cholesterol Numbers All men should have their blood cholesterol ...

  16. Cholesterol testing and results

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000386.htm Cholesterol testing and results To use the sharing features ... can tell you what your goal should be. Cholesterol Tests Some cholesterol is considered good and some ...

  17. Cholesterol Facts and Statistics

    Science.gov (United States)

    ... Blood Pressure Salt Million Hearts® WISEWOMAN Program High Cholesterol Facts Recommend on Facebook Tweet Share Compartir As ... the facts about high cholesterol [PDF-281K] . High Cholesterol in the United States 73.5 million adults ( ...

  18. Optimization, production and characterization of glycolipid biosurfactant from the marine actinobacterium, Streptomyces sp. MAB36.

    Science.gov (United States)

    Manivasagan, Panchanathan; Sivasankar, Palaniappan; Venkatesan, Jayachandran; Sivakumar, Kannan; Kim, Se-Kwon

    2014-05-01

    A potential glycolipid biosurfactant producer Streptomyces sp. MAB36 was isolated from marine sediment samples. Medium composition and culture conditions for the glycolipid biosurfactant production by Streptomyces sp. MAB36 were optimized, using two statistical methods: Plackett-Burman design was applied to find out the key ingredients and conditions for the best yield of glycolipid biosurfactant production and central composite design was used to optimize the concentration of the four significant variables, starch, casein, crude oil and incubation time. Fructose and yeast extract were the best carbon and nitrogen sources for the production of the glycolipid biosurfactant. Biochemical characterizations including FTIR and MS studies suggested the glycolipid nature of the biosurfactant. The isolated glycolipid biosurfactant reduced the surface tension of water from 73.2 to 32.4 mN/m. The purified glycolipid biosurfactant showed critical micelle concentrations of 36 mg/l. The glycolipid biosurfactant was effective at very low concentrations over a wide range of temperature, pH, and NaCl concentration. The purified glycolipid biosurfactant showed strong antimicrobial activity. Thus, the strain Streptomyces sp. MAB36 has proved to be a potential source of glycolipid biosurfactant that could be used for the bioremediation processes in the marine environment. PMID:24061563

  19. Reverse cholesterol transport revisited

    Institute of Scientific and Technical Information of China (English)

    Astrid; E; van; der; Velde

    2010-01-01

    Reverse cholesterol transport was originally described as the high-density lipoprotein-mediated cholesterol flux from the periphery via the hepatobiliary tract to the intestinal lumen, leading to fecal excretion. Since the introduction of reverse cholesterol transport in the 1970s, this pathway has been intensively investigated. In this topic highlight, the classical reverse cholesterol transport concepts are discussed and the subject reverse cholesterol transport is revisited.

  20. Novel phenolic glycolipids: antioxidant activity and effect on membrane models

    OpenAIRE

    Sainvitu, Pauline; Nasir, Mehmet Nail; Draguet, Florian; Nott, Katherine; Lins, Laurence; Crowet, Jean-Marc; Willems, Luc; Cosse, Jean-Philippe; Jérôme, Christine; Deleu, Magali

    2013-01-01

    Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit co...

  1. Glycolipids from a colloid chemical point of view.

    Science.gov (United States)

    Thiesen, P H; Rosenfeld, H; Konidala, P; Garamus, V M; He, L; Prange, A; Niemeyer, B

    2006-06-25

    Glycolipids are a group of compounds with a broad range of applications. Two types of glycolipids (alkylpolyglycosides and gangliosides) were examined with regard to their physicochemical properties. Despite their structural differences, they have in common that they are amphiphilic molecules and able to aggregate to form monolayers, bilayers, micelles, lyothropic mesophases or vesicles. The structures of glycolipid micelles were investigated by different experimental techniques in addition to molecular dynamic simulations. The knowledge of the physicochemical properties of gangliosides enables a better understanding of their biological functions. Structural features were obtained for the monosialogangliosides GM1, GM2 and GT1b from bovine brain by means of mass spectrometry. Further the aggregation behaviour was determined by small-angle neutron and dynamic light scattering experiments. Interaction studies of these compounds were carried out by means of surface plasmon resonance using gangliosides incorporated liposomes. They were used as model membranes that interact with the lectins WGA, RCA and HPA. The interaction of lectins immobilized to a modified silicon surface was investigated by in-situ ellipsometry. PMID:16707183

  2. Peroxisomes contribute to biosynthesis of extracellular glycolipids in fungi.

    Science.gov (United States)

    Freitag, Johannes; Ast, Julia; Linne, Uwe; Stehlik, Thorsten; Martorana, Domenica; Bölker, Michael; Sandrock, Björn

    2014-07-01

    Many microorganisms secrete surface-active glycolipids. The basidiomycetous fungus Ustilago maydis produces two different classes of glycolipids, mannosylerythritol lipids (MEL) and ustilagic acids (UAs). Here we report that biosynthesis of MELs is partially localized in peroxisomes and coupled to peroxisomal fatty acid degradation. The acyltransferases, Mac1 and Mac2, which acylate mannosylerythritol with fatty acids of different length, contain a type 1 peroxisomal targeting signal (PTS1). We demonstrate that Mac1 and Mac2 are targeted to peroxisomes, while other enzymes involved in MEL production reside in different compartments. Mis-targeting of Mac1 and Mac2 to the cytosol did not block MEL synthesis but promoted production of MEL species with altered acylation pattern. This is in contrast to peroxisome deficient mutants that produced MELs similar to the wild type. We could show that cytosolic targeting of Mac1 and Mac2 reduces the amount of UA presumably due to competition for overlapping substrates. Interestingly, hydroxylated fatty acids characteristic for UAs appear in MELs corroborating cross-talk between both biosynthesis pathways. Therefore, peroxisomal localization of MEL biosynthesis is not only prerequisite for generation of the natural spectrum of MELs, but also facilitates simultaneous assembly of different glycolipids in a single cell. PMID:24835306

  3. Constrained wormholes

    International Nuclear Information System (INIS)

    The large wormhole problem in Coleman's theory of the cosmological constant is presented in the framework of constrained wormholes. We use semi-classical methods, similar to those used to study constrained instantons in quantum field theory. A scalar field theory serves as a toy model to analyze the problems associated with large constrained instantons. In particular, these large instantons are found to suffer from large quantum fluctuations. In gravity we find the same situation: large quantum fluctuations around large wormholes. In both cases we expect that these large fluctuations are a signal that large constrained solutions are not important in the path integral. Thus, we argue that only small wormholes are important in Coleman's theory. (orig.)

  4. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    OpenAIRE

    Ikegami Toru; Yanagishita Hiroshi; Nakane Takashi; Im Jae Hong; Kitamoto Dai

    2001-01-01

    Abstract Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand...

  5. Two-enzyme systems for glycolipid and polyglycerolphosphate lipoteichoic acid synthesis in Listeria monocytogenes

    OpenAIRE

    Webb, Alexander J; Karatsa-Dodgson, Maria; Gründling, Angelika

    2009-01-01

    Lipoteichoic acid (LTA) is an important cell wall polymer in Gram-positive bacteria and often consists a polyglycerolphosphate backbone chain that is linked to the membrane by a glycolipid. In Listeria monocytogenes this glycolipid is Gal-Glc-DAG or Gal-Ptd-6Glc-DAG. Using a bioinformatics approach, we have identified L. monocytogenes genes predicted to be involved in glycolipid (lmo2555 and lmo2554) and LTA backbone (lmo0644 and lmo0927) synthesis. LTA and glycolipid analysis of wild-type an...

  6. A basidiomycetous yeast, Pseudozyma crassa, produces novel diastereomers of conventional mannosylerythritol lipids as glycolipid biosurfactants.

    Science.gov (United States)

    Fukuoka, Tokuma; Kawamura, Mayo; Morita, Tomotake; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2008-11-24

    Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by the yeast strains of the genus Pseudozyma. These compounds show not only excellent surface-active properties, but also versatile biochemical actions. During a survey of new MEL producers, we found that a basidiomycetous yeast, Pseudozyma crassa, extracellularly produces three glycolipids. When glucose and oleic acid were used as the carbon source, the total amount of glycolipids reached approximately 4.6g/L in the culture medium. The structures of these glycolipids were similar to those of well-known MEL-A, -B, and -C, respectively. Very interestingly, in all the present glycolipids, the configuration of the erythritol moiety was entirely opposite to that of conventional MELs. The present glycolipids were identified to have the carbohydrate structure of 4-O-beta-D-mannopyranosyl-(2R,3S)-erythritol, stereochemically different from 4-O-beta-D-mannopyranosyl-(2S,3R)-erythritol of conventional MELs. Furthermore, these new glycolipids possessed both short-chain acids (C(2) or C(4)) and long-chain acids (C(14), C(16), or C(18)) on the mannose moiety. The major component of the present glycolipids clearly showed different interfacial and biological properties, compared to conventional MELs comprising two medium-chain acids on the mannose moiety. Accordingly, the novel MEL diastereomers produced by P. crassa should provide us with different glycolipid functions, and facilitate a broad range of applications of MELs. PMID:18805521

  7. Cholesterol - drug treatment

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000314.htm Cholesterol - drug treatment To use the sharing features on ... treatment; Hardening of the arteries - statin Statins for Cholesterol Statins reduce your risk of heart disease, stroke, ...

  8. Get Your Cholesterol Checked

    Science.gov (United States)

    ... You also get cholesterol by eating foods like egg yolks, fatty meats, and regular cheese. If you have too much cholesterol in your body, it can build up inside your blood vessels and make it hard for blood to ...

  9. Common Misconceptions about Cholesterol

    Science.gov (United States)

    ... your doctor recommends. Learn more about eating a healthy diet. Thin people don't have to worry about high cholesterol. A person with any body type can have high cholesterol. Overweight people are more likely to have ... heart-healthy. Have your cholesterol checked regularly regardless of your ...

  10. Home-Use Tests - Cholesterol

    Science.gov (United States)

    ... Medical Procedures In Vitro Diagnostics Home Use Tests Cholesterol Share Tweet Linkedin Pin it More sharing options ... a home-use test kit to measure total cholesterol. What cholesterol is: Cholesterol is a fat (lipid) ...

  11. Recognition of microbial glycolipids by Natural Killer T cells

    Directory of Open Access Journals (Sweden)

    Dirk Michael Zajonc

    2015-08-01

    Full Text Available T cells can recognize microbial antigens when presented by dedicated antigen-presenting molecules. While peptides are presented by classical members of the Major Histocompatibility (MHC family (MHC I and II, lipids, glycolipids and lipopeptides can be presented by the non-classical MHC member CD1. The best studied subset of lipid-reactive T cells are Type I Natural killer T (iNKT cells that recognize a variety of different antigens when presented by the non-classical MHCI homolog CD1d. iNKT cells have been shown to be important for the protection against various microbial pathogens, including B. burgdorferi the causative agents of Lyme disease and S. pneumoniae, which causes pneumococcal meningitis and community-acquired pneumonia. Both pathogens carry microbial glycolipids that can trigger the T cell antigen receptor (TCR, leading to iNKT cell activation. iNKT cells have an evolutionary conserved TCR alpha chain, yet retain the ability to recognize structurally diverse glycolipids. They do so using a conserved recognition mode, in which the TCR enforces a conserved binding orientation on CD1d. TCR binding is accompanied by structural changes within the TCR binding site of CD1d, as well as the glycolipid antigen itself. In addition to direct recognition of microbial antigens, iNKT cells can also be activated by a combination of cytokines (IL-12/IL-18 and TCR stimulation. Many microbes carry TLR antigens and microbial infections can lead to TLR activation. The subsequent cytokine response in turn lower the threshold of TCR mediated iNKT cell activation, especially when weak microbial or even self-antigens are presented during the cause of the infection. In summary, iNKT cells can be directly activated through TCR triggering of strong antigens, while cytokines produced by the innate immune response may be necessary for TCR triggering and iNKT cell activation in the presence of weak antigens. Here we will review the molecular basis of iNKT cell

  12. Trehalose Polyphleates Are Produced by a Glycolipid Biosynthetic Pathway Conserved across Phylogenetically Distant Mycobacteria.

    Science.gov (United States)

    Burbaud, Sophie; Laval, Françoise; Lemassu, Anne; Daffé, Mamadou; Guilhot, Christophe; Chalut, Christian

    2016-02-18

    Mycobacteria synthesize a variety of structurally related glycolipids with major biological functions. Common themes have emerged for the biosynthesis of these glycolipids, including several families of proteins. Genes encoding these proteins are usually clustered on bacterial chromosomal islets dedicated to the synthesis of one glycolipid family. Here, we investigated the function of a cluster of five genes widely distributed across non-tuberculous mycobacteria. Using defined mutant analysis and in-depth structural characterization of glycolipids from wild-type or mutant strains of Mycobacterium smegmatis and Mycobacterium abscessus, we established that they are involved in the formation of trehalose polyphleates (TPP), a family of compounds originally described in Mycobacterium phlei. Comparative genomics and lipid analysis of strains distributed along the mycobacterial phylogenetic tree revealed that TPP is synthesized by a large number of non-tuberculous mycobacteria. This work unravels a novel glycolipid biosynthetic pathway in mycobacteria and extends the spectrum of bacteria that produce TPP. PMID:27028886

  13. Thiolactosides: Scaffolds for the Synthesis of Glycolipids in Animal Cells

    Directory of Open Access Journals (Sweden)

    Masako Mori

    2011-01-01

    Full Text Available Various glycolipids were synthesized using thiolactosides as scaffolds for glycosylation in animal cells. The basic building blocks, n-dodecyl β-D-thiolactoside (β-LacSC12 and n-dodecyl α-D-thiolactoside (α-LacSC12, were chemically synthesized in 2 steps: glycosylation followed by deacylation. The thiolactosides were administered to animal cells in culture and served as substrates for cellular enzyme-catalyzed glycosylation. Incubation of mouse melanoma B16 cells in the presence of β-LacSC12 or α-LacSC12 resulted in sialylation of the terminal galactose residue and gave a GM3-type ganglioside. Administration of β-Lac SC12 in Madin-Darby canine kidney (MDCK cells likewise gave a GM3-type ganglioside. On the other hand, introduction of β-LacSC12 in African green monkey kidney (Vero cells gave Gb3- and Gb4-type glycolipids aside from GM3-type ganglioside. In the course of the study, significant changes in B16 cell morphology and elevated secretion of melanin were also observed.

  14. Characterization of glycolipids synthesized in an identified neuron of Aplysia californica

    International Nuclear Information System (INIS)

    Because radioactive precursors can be injected directly into the cell body or axon of R2, a giant, identified neuron of the Aplysia abdominal ganglion, it was possible to show that glycolipid is synthesized in the cell body, inserted into membranes along with glycoprotein, and then exported into the axon within organelles that are moved by fast axonal transport. After intrasomatic injection of N-[3H]-acetyl-D-galactosamine, five major 3H-glycolipids were identified using thin layer polysilicic acid glass fiber chromatography. At least two of the lipids are negatively charged. Analysis of 32P-labeled lipid from the abdominal ganglion revealed the presence of 2-aminoethylphosphonate, indicating that these polar substances are sphingophosphonoglycolipids. The major 3H-glycolipids synthesized in R2 are similar to a family of phospholipids isolated from the skin of A. kurodai. Since sialic acid is absent in Aplysia as in other invertebrates, these polar glycolipids may function like gangliosides in vertebrates. The polar 3H-glycolipids are synthesized and incorporated into intracytoplasmic membranes solely in the cell body. Direct injection of the labeled sugar into the axon revealed no local synthesis or exchange of glycolipid. Moreover, there was no indication for transfer from glial cells into axoplasm. Although the incorporation of N-[3H]-acetyl-D-galactosamine into glycolipid is not affected by anisomycin, an effective inhibitor of protein synthesis, the export into the axon of membranes containing the newly synthesized lipid is completely blocked by the drug

  15. Glycolipid biosurfactants: main properties and potential applications in agriculture and food industry.

    Science.gov (United States)

    Mnif, Inès; Ghribi, Dhouha

    2016-10-01

    Glycolipids, consisting of a carbohydrate moiety linked to fatty acids, are microbial surface active compounds produced by various microorganisms. They are characterized by high structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface, respectively. Rhamnolipids, trehalolipids, mannosylerythritol lipids and cellobiose lipids are among the most popular glycolipids. They have received much practical attention as biopesticides for controlling plant diseases and protecting stored products. As a result of their antifungal activity towards phytopathogenic fungi and larvicidal and mosquitocidal potencies, glycolipid biosurfactants permit the preservation of plants and plant crops from pest invasion. Also, as a result of their emulsifying and antibacterial activities, glycolipids have great potential as food additives and food preservatives. Furthermore, the valorization of food byproducts via the production of glycolipid biosurfactant has received much attention because it permits the bioconversion of byproducts on valuable compounds and decreases the cost of production. Generally, the use of glycolipids in many fields requires their retention from fermentation media. Accordingly, different strategies have been developed to extract and purify glycolipids. © 2016 Society of Chemical Industry. PMID:27098847

  16. Tangled evolutionary processes with commonality and diversity in plastidial glycolipid synthesis in photosynthetic organisms.

    Science.gov (United States)

    Hori, Koichi; Nobusawa, Takashi; Watanabe, Tei; Madoka, Yuka; Suzuki, Hideyuki; Shibata, Daisuke; Shimojima, Mie; Ohta, Hiroyuki

    2016-09-01

    In photosynthetic organisms, the photosynthetic membrane constitutes a scaffold for light-harvesting complexes and photosynthetic reaction centers. Three kinds of glycolipids, namely monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol, constitute approximately 80-90% of photosynthetic membrane lipids and are well conserved from tiny cyanobacteria to the leaves of huge trees. These glycolipids perform a wide variety of functions beyond biological membrane formation. In particular, the capability of adaptation to harsh environments through regulation of membrane glycolipid composition is essential for healthy growth and development of photosynthetic organisms. The genome analysis and functional genetics of the model seed plant Arabidopsis thaliana have yielded many new findings concerning the biosynthesis, regulation, and functions of glycolipids. Nevertheless, it remains to be clarified how the complex biosynthetic pathways and well-organized functions of glycolipids evolved in early and primitive photosynthetic organisms, such as cyanobacteria, to yield modern photosynthetic organisms like land plants. Recently, genome data for many photosynthetic organisms have been made available as the fruit of the rapid development of sequencing technology. We also have reported the draft genome sequence of the charophyte alga Klebsormidium flaccidum, which is an intermediate organism between green algae and land plants. Here, we performed a comprehensive phylogenic analysis of glycolipid biosynthesis genes in oxygenic photosynthetic organisms including K. flaccidum. Based on the results together with membrane lipid analysis of this alga, we discuss the evolution of glycolipid synthesis in photosynthetic organisms. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:27108062

  17. National Cholesterol Education Month

    Centers for Disease Control (CDC) Podcasts

    2009-09-01

    Do you know your cholesterol numbers? Your doctor can do a simple test to check your cholesterol levels and help you make choices that lower your risk for heart disease and stroke.  Created: 9/1/2009 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 9/9/2009.

  18. Bile acid sequestrants for cholesterol

    Science.gov (United States)

    ... ency/patientinstructions/000787.htm Bile acid sequestrants for cholesterol To use the sharing features on this page, ... are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can stick ...

  19. What Causes High Blood Cholesterol?

    Science.gov (United States)

    ... the NHLBI on Twitter. What Causes High Blood Cholesterol? Many factors can affect the cholesterol levels in your blood. You can control some ... but not others. Factors You Can Control Diet Cholesterol is found in foods that come from animal ...

  20. Stimulation of adult neural stem cells with a novel glycolipid biosurfactant

    OpenAIRE

    Stipcevic, Tamara; Knight, Christopher P.; Kippin, Tod E.

    2013-01-01

    Glycolipids are amphipatic molecules which are highly expressed on cell membranes in skin and brain where they mediate several key cellular processes. Neural stem cells are defined as undifferentiated, proliferative, multipotential cells with extensive self-renewal and are responsive to brain injury. Di-rhamnolipid: α-L-rhamnopyranosyl-(1-2)α-L-rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoic acid, also referred to as di-rhamnolipid BAC-3, is a glycolipid isolated from bacteria Pseudomonas...

  1. Ethanolamine-phosphate modified glycolipids in Clostridium acetobutylicum that respond to membrane stress

    OpenAIRE

    Tian, Bing; Guan, Ziqiang; Goldfine, Howard

    2013-01-01

    Two phosphorus-containing glycolipids have previously been observed in Clostridium acetobutylicum. We had shown that the concentration of one of them increases in response to increased unsaturation of the membrane lipid hydrocarbon chains, suggesting a potential role in the regulation of lipid polymorphism in this organism. Mass spectrometry shows that these glycolipids are ethanolamine phosphate (Etn-P)-containing derivatives of a mono- and diglycosyldiradylglycerol. The content of both digl...

  2. In Vitro Biosynthesis of Ether-Type Glycolipids in the Methanoarchaeon Methanothermobacter thermautotrophicus▿

    OpenAIRE

    Morii, Hiroyuki; Eguchi, Tadashi; Koga, Yosuke

    2007-01-01

    The biosynthesis of archaeal ether-type glycolipids was investigated in vitro using Methanothermobacter thermautotrophicus cell-free homogenates. The sole sugar moiety of glycolipids and phosphoglycolipids of the organism is the β-d-glucosyl-(1→6)-d-glucosyl (gentiobiosyl) unit. The enzyme activities of archaeol:UDP-glucose β-glucosyltransferase (monoglucosylarchaeol [MGA] synthase) and MGA:UDP-glucose β-1,6-glucosyltransferase (diglucosylarchaeol [DGA] synthase) were found in the methanoarch...

  3. Glycolipid Transfer Protein Interaction with Bilayer Vesicles: Modulation by Changing Lipid Composition

    OpenAIRE

    Rao, Chetan S; Chung, Taeowan; Pike, Helen M.; Brown, Rhoderick E.

    2005-01-01

    Glycosphingolipids (GSLs) are important constituents of lipid rafts and caveolae, are essential for the normal development of cells, and are adhesion sites for various infectious agents. One strategy for modulating GSL composition in lipid rafts is to selectively transfer GSL to or from these putative membrane microdomains. Glycolipid transfer protein (GLTP) catalyzes selective intermembrane transfer of GSLs. To enable effective use of GLTP as a tool to modify the glycolipid content of membra...

  4. Hopanoids as functional analogues of cholesterol in bacterial membranes.

    Science.gov (United States)

    Sáenz, James P; Grosser, Daniel; Bradley, Alexander S; Lagny, Thibaut J; Lavrynenko, Oksana; Broda, Martyna; Simons, Kai

    2015-09-22

    The functionality of cellular membranes relies on the molecular order imparted by lipids. In eukaryotes, sterols such as cholesterol modulate membrane order, yet they are not typically found in prokaryotes. The structurally similar bacterial hopanoids exhibit similar ordering properties as sterols in vitro, but their exact physiological role in living bacteria is relatively uncharted. We present evidence that hopanoids interact with glycolipids in bacterial outer membranes to form a highly ordered bilayer in a manner analogous to the interaction of sterols with sphingolipids in eukaryotic plasma membranes. Furthermore, multidrug transport is impaired in a hopanoid-deficient mutant of the gram-negative Methylobacterium extorquens, which introduces a link between membrane order and an energy-dependent, membrane-associated function in prokaryotes. Thus, we reveal a convergence in the architecture of bacterial and eukaryotic membranes and implicate the biosynthetic pathways of hopanoids and other order-modulating lipids as potential targets to fight pathogenic multidrug resistance. PMID:26351677

  5. Glycosylation of Glycolipids in Cancer: Basis for Development of Novel Therapeutic Approaches

    Directory of Open Access Journals (Sweden)

    JoseLuisDaniotti

    2013-12-01

    Full Text Available Altered networks of gene regulation underlie many pathologies, including cancer. There are several proteins in cancer cells that are turned either on or off, which dramatically alters the metabolism and the overall activity of the cell, with the complex machinery of enzymes involved in the metabolism of glycolipids not being an exception. The aberrant glycosylation of glycolipids on the surface of the majority of cancer cells, associated with increasing evidence about the functional role of these molecules in a number of cellular physiological pathways, has received considerable attention as a convenient immunotherapeutic target for cancer treatment. This has resulted in the development of a substantial number of passive and active immunotherapies, which have shown promising results in clinical trials. More recently, antibodies to glycolipids have also emerged as an attractive tool for the targeted delivery of cytotoxic agents, thereby providing a rationale for future therapeutic interventions in cancer. This review first summarizes the cellular and molecular bases involved in the metabolic pathway and expression of glycolipids, both in normal and tumor cells, paying particular attention to sialosylated glycolipids (gangliosides. The current strategies in the battle against cancer in which glycolipids are key players are then described.

  6. D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol alters cellular cholesterol homeostasis by modulating the endosome lipid domains.

    Science.gov (United States)

    Makino, Asami; Ishii, Kumiko; Murate, Motohide; Hayakawa, Tomohiro; Suzuki, Yusuke; Suzuki, Minoru; Ito, Kazuki; Fujisawa, Tetsuro; Matsuo, Hirotami; Ishitsuka, Reiko; Kobayashi, Toshihide

    2006-04-11

    D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP) is a frequently used inhibitor of glycosphingolipid biosynthesis. However, some interesting characteristics of D-PDMP cannot be explained by the inhibition of glycolipid synthesis alone. In the present study, we showed that d-PDMP inhibits the activation of lysosomal acid lipase by late endosome/lysosome specific lipid, bis(monoacylglycero)phosphate (also called as lysobisphosphatidic acid), through alteration of membrane structure of the lipid. When added to cultured fibroblasts, D-PDMP inhibits the degradation of low-density lipoprotein (LDL) and thus accumulates both cholesterol ester and free cholesterol in late endosomes/lysosomes. This accumulation results in the inhibition of LDL-derived cholesterol esterification and the decrease of cell surface cholesterol. We showed that D-PDMP alters cellular cholesterol homeostasis in a glycosphingolipid-independent manner using L-PDMP, a stereoisomer of D-PDMP, which does not inhibit glycosphingolipid synthesis, and mutant melanoma cell which is defective in glycolipid synthesis. Altering cholesterol homeostasis by D-PDMP explains the unique characteristics of sensitizing multidrug resistant cells by this drug. PMID:16584188

  7. Lifestyle Changes and Cholesterol

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Lifestyle Changes and Cholesterol Updated:Oct 26,2015 As ... disease and stroke, your doctor may suggest some lifestyle changes. Regardless of whether your plan includes drug ...

  8. HDL cholesterol: atherosclerosis and beyond

    OpenAIRE

    Stroes, E. S. G.; Hovingh, G. K.; Kuivenhoven, J. A.; Bochem, A.E.

    2013-01-01

    Cardiovascular disease (CVD) is the leading cause of death in the Western world. Myocardial infarction and stroke are the result of a compromised blood flow which may result from cholesterol accumulation in the vessel wall due to high plasma levels of LDL cholesterol. High plasma levels of HDL cholesterol, however, are inversely associated with CVD. This is commonly ascribed to a concept called "reverse cholesterol transport" a mechanism by which the HDL particle takes up cholesterol from the...

  9. Pachymoside A - a novel glycolipid isolated from the marine sponge Pachymatisma johnstonia

    Energy Technology Data Exchange (ETDEWEB)

    Warabi, K.; Zimmerman, W.T.; Shen, J. [Univ. of British Columbia, Departments of Chemistry, Earth and Ocean Sciences, Vancouver, British Columbia (Canada); Gauthier, A.; Robertson, M.; Finlay, B.B. [Univ. of British Columbia, Departments of Biochemistry and Microbiology, Vancouver, British Columbia (Canada); Van Soest, R. [Univ. of Amsterdam, Dept. of Coelenterates and Porifera, Zoologisch Museum, Amsterdam (Netherlands); Andersen, R.J. [Univ. of British Columbia, Departments of Chemistry, Earth and Ocean Sciences, Vancouver, British Columbia (Canada)]. E-mail: randersn@interchange.ubc.ca

    2004-02-01

    Crude extracts of the North Sea marine sponge Pachymatisma johnstonia showed promising activity in a new assay for inhibitors of bacterial type III secretion. Bioassay-guided fractionation resulted in the isolation of the pachymosides, a new family of sponge glycolipids. A major part of the structural diversity in this family of glycolipids involves increasing degrees of acetylation and differing positions of acetylation on a common pachymoside glycolipid template. All of the metabolites with these variations in acetylation pattern were converted into the same peracetyl-pachymoside methyl ester (2) for purification and spectroscopic analysis. Pachymoside A (1) is the component of the mixture that has natural acetylation at the eight galactose hydroxyls and at the C-6 hydroxyls of glucose-B and glucose-D. Chemical degradation and transformation in conjunction with extensive analysis of 800 MHz NMR data was used to elucidate the structure of pachymoside A (1). (author)

  10. Pachymoside A - a novel glycolipid isolated from the marine sponge Pachymatisma johnstonia

    International Nuclear Information System (INIS)

    Crude extracts of the North Sea marine sponge Pachymatisma johnstonia showed promising activity in a new assay for inhibitors of bacterial type III secretion. Bioassay-guided fractionation resulted in the isolation of the pachymosides, a new family of sponge glycolipids. A major part of the structural diversity in this family of glycolipids involves increasing degrees of acetylation and differing positions of acetylation on a common pachymoside glycolipid template. All of the metabolites with these variations in acetylation pattern were converted into the same peracetyl-pachymoside methyl ester (2) for purification and spectroscopic analysis. Pachymoside A (1) is the component of the mixture that has natural acetylation at the eight galactose hydroxyls and at the C-6 hydroxyls of glucose-B and glucose-D. Chemical degradation and transformation in conjunction with extensive analysis of 800 MHz NMR data was used to elucidate the structure of pachymoside A (1). (author)

  11. Characterization of new glycolipid biosurfactants, tri-acylated mannosylerythritol lipids, produced by Pseudozyma yeasts.

    Science.gov (United States)

    Fukuoka, Tokuma; Morita, Tomotake; Konishi, Masaaki; Imura, Tomohiro; Kitamoto, Dai

    2007-07-01

    Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by Pseudozyma yeasts. They show not only the excellent interfacial properties but also versatile biochemical actions. In the course of MEL production from soybean oil by P. antarctica and P. rugulosa, some new extracellular glycolipids (more hydrophobic than the previously reported di-acylated MELs) were found in the culture medium. The most hydrophobic one was identified as 1-O-alka(e)noyl-4-O-[(4',6'-di-O-acetyl-2',3'-di-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol, namely tri-acylated MEL. Others were tri-acylated MELs bearing only one acetyl group. The tri-acylated MEL could be prepared by the lipase-catalyzed esterification of a di-acylated MEL with oleic acid implying that the new glycolipids are synthesized from di-acylated MELs in the culture medium containing the residual fatty acids. PMID:17417694

  12. Production of a novel glycolipid biosurfactant, mannosylmannitol lipid, by Pseudozyma parantarctica and its interfacial properties.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Konishi, Masaaki; Imura, Tomohiro; Yamamoto, Shuhei; Kitagawa, Masaru; Sogabe, Atsushi; Kitamoto, Dai

    2009-07-01

    The development of a novel glycolipid biosurfactant was undertaken using the high-level producers of mannosylerythritol lipids (MELs) such as Pseudozyma parantarctica, Pseudozyma antarctica, and Pseudozyma rugulosa. Besides the conventional MELs (MEL-A, MEL-B, and MEL-C), these yeasts produced an unknown glycolipid when they were cultivated in a medium containing 4% (w/v) olive oil and 4% (w/w) mannitol as the carbon source. The unknown glycolipid extracted from the culture medium of P. parantarctica JCM 11752(T) displayed the spot with lower mobility than that of known MELs on TLC and provided mainly two peaks identical to mannose and mannitol on high-performance liquid chromatography after acid hydrolysis. Based on structural analysis by (1)H and (13)C nuclear magnetic resonance, the novel glycolipid was composed of mannose and mannitol as the hydrophilic sugar moiety and was identified as mannosylmannitol lipid (MML). Of the strains tested, P. parantarctica JCM 11752(T) gave the best yield of MML (18.2 g/L), which comprised approximately 35% of all glycolipids produced. We further investigated the interfacial properties of the MML, considering the unique hydrophilic structure. The observed critical micelle concentration (CMC) and the surface tension at CMC of the MML were 2.6 x 10(-6) M and 24.2 mN/m, respectively. In addition, on a water-penetration scan, the MML efficiently formed not only the lamella phase (Lalpha) but also the myelins at a wide range of concentrations, indicating its excellent self-assembling properties and high hydrophilicity. The present glycolipid should thus facilitate the application of biosurfactants as new functional materials. PMID:19296097

  13. Regulation of cholesterol homeostasis

    NARCIS (Netherlands)

    van der Wulp, Mariette Y. M.; Verkade, Henkjan J.; Groen, Albert K.

    2013-01-01

    Hypercholesterolemia is an important risk factor for cardiovascular disease. It is caused by a disturbed balance between cholesterol secretion into the blood versus uptake. The pathways involved are regulated via a complex interplay of enzymes, transport proteins, transcription factors and non-codin

  14. The neurite-initiating effect of microbial extracellular glycolipids in PC12 cells

    OpenAIRE

    Isoda, Hiroko; Shinmoto, Hiroshi; Matsumura, Masatoshi; Nakahara, Tadaatsu

    1999-01-01

    The effects of several kinds of microbial extracellular glycolipids on neurite initiation in PC12 cells were examined. Addition of mannosylerythritol lipid-A (MEL-A), MEL-B, and sophorose lipid (SL) to PC12 cells caused significant neurite outgrowth. Other glycolipids, such as polyol lipid (PL), rhamnose lipid (RL), succinoyl trehalose lipid-A (STL-A) and STL-B caused no neurite-initiation. MEL-A increased acetylcholine esterase (AChE) activity to an extent similar to nerve growth factor (NGF...

  15. Characterization of placental cholesterol transport

    DEFF Research Database (Denmark)

    Lindegaard, Marie L; Wassif, Christopher A; Vaisman, Boris;

    2008-01-01

    cholesterol, in utero treatment with TO901317 resulted in increased cholesterol content in Dhcr7(-/-) embryos. Our data support the hypothesis that Abca1, and possibly Sr-b1, contributes to transport maternal cholesterol to the developing fetus. Furthermore, we show, as a proof of principle, that modulating......Patients with Smith-Lemli-Opitz syndrome (SLOS) are born with multiple congenital abnormalities. Postnatal cholesterol supplementation is provided; however, it cannot correct developmental malformations due to in utero cholesterol deficit. Increased transport of cholesterol from maternal to fetal...... embryonic days 13.5 and 18.5 in placental tissue; whereas, Sr-b1 expression decreased. To examine the functional role of Abca1, Abcg1 and Sr-b1 we measured the maternal-fetal transfer of (14)C-cholesterol in corresponding mutant embryos. Disruption of either Abca1 or Sr-b1 decreased cholesterol transfer by...

  16. What Your Cholesterol Levels Mean

    Science.gov (United States)

    ... Blood Pressure Tools & Resources Stroke More What Your Cholesterol Levels Mean Updated:Aug 9,2016 How’s your ... the Terms and Conditions and Privacy Policy Interactive Cholesterol Guide Find videos, trackers and more with our ...

  17. Effects of dietary cholesterol on cholesterol and bile acid homeostasis in patients with cholesterol gallstones.

    OpenAIRE

    Kern, F

    1994-01-01

    We examined changes in cholesterol and bile acid metabolism produced by dietary cholesterol in gallstone subjects and matched controls. Healthy women were recruited and, after confirming the presence or absence of radiolucent gallstones, they were studied on regular diets and again on the same diet supplemented with five eggs daily for 15-18 d. Studies included plasma lipids, lipoproteins and apolipoproteins, dietary records, cholesterol absorption, cholesterol synthesis, plasma clearance of ...

  18. Influence of Working Stress on Glycolipid Metabolism of Military Pilots%飞行人员工作应激对糖脂代谢的影响

    Institute of Scientific and Technical Information of China (English)

    翁庐英; 赵璧; 吴思英

    2012-01-01

    Objective To investigate the status of military pilots' working stress and its influence on glycolipid metabolism,so as to provide theoretical evidence for psychological and physical health of military pilots. Methods By convenience sampling,500 military pilots in Shanghai and Hangzhou were surveyed on their working stress. Simultaneously,the physiological and biochemical indicators (cholesterol,triglycer-ides,high density lipoprotein,and glycated hemoglobin) were measured. The influence of working stress of military pilots' on the glycolipid metabolism were analyzed accordingly. Results For the military pilots,the total score of working stress and the scores of physical condition stress and working interest were higher than those of the national norm(P0. 05). After the adjustment for age factors,the levels of triglyceride,high-density lipoprotein and systolic and diastolic pressures were significantly higher in the high working stress group than in the normal working stress group(P0.05).在调整了年龄因素后,高工作应激组的三酰甘油水平、高密度脂蛋白水平、收缩压和舒张压水平均高于正常工作应激组(P<0.05或P<0.01).结论 工作应激是飞行人员糖脂代谢异常的危险因素,应做好相关的预防及保健工作,以提高飞行人员群体的身心健康水平.

  19. Lysosomes, cholesterol and atherosclerosis

    OpenAIRE

    Jerome, W. Gray

    2010-01-01

    Cholesterol-engorged macrophage foam cells are a critical component of the atherosclerotic lesion. Reducing the sterol deposits in lesions reduces clinical events. Sterol accumulations within lysosomes have proven to be particularly hard to mobilize out of foam cells. Moreover, excess sterol accumulation in lysosomes has untoward effects, including a complete disruption of lysosome function. Recently, we demonstrated that treatment of sterol-engorged macrophages in culture with triglyceride-c...

  20. The challenges of understanding glycolipid functions: An open outlook based on molecular simulations

    DEFF Research Database (Denmark)

    Manna, M.; Rog, T.; Vattulainen, I.

    2014-01-01

    Glycolipids are the most complex lipid type in cell membranes, characterized by a great diversity of different structures and functions. The underlying atomistic/molecular interactions and mechanisms associated with these functions are not well understood. Here we discuss how atomistic and molecu...

  1. Endosymbiotic heterocystous cyanobacteria synthesize different heterocyst glycolipids than free-living heterocystous cyanobacteria

    NARCIS (Netherlands)

    Schouten, S.; Villareal, T.A.; Hopmans, E.C.; Mets, A.; Swanson, K.M.; Sinninghe Damsté, J.S.

    2013-01-01

    The heterocysts of limnetic nitrogen-fixing filamentous cyanobacteria contain unique glycolipids in their cell wall that create the distinctive gas impermeability of the heterocyst cell wall as well as serve as biomarker lipids for these microbes. It has been assumed that marine free-living and endo

  2. Long chain glycolipids with pentose head groups as biomarkers for marine endosymbiotic heterocystous cyanobacteria

    NARCIS (Netherlands)

    Bale, N.; Hopmans, E.C.; Zell, C.; Sobrinho, R.; Kim, J.H.; Sinninghe Damsté, J.S.; Villareal, T.A.; Schouten, S.

    2015-01-01

    Marine endosymbiotic heterocystous cyanobacteria make unique heterocyst glycolipids (HGs) containing pentose (C5) moieties. Functionally similar HGs with hexose (C6) moieties found in free-living cyanobacteria occur in the sedimentary record, but C5 HGs have not been documented in the natural enviro

  3. Antifungal Activity of Flocculosin, a Novel Glycolipid Isolated from Pseudozyma flocculosa

    OpenAIRE

    Mimee, Benjamin; Labbé, Caroline; Pelletier, René; Bélanger, Richard R.

    2005-01-01

    Flocculosin, a glycolipid isolated from the yeast-like fungus Pseudozyma flocculosa, was investigated for in vitro antifungal activity. The compound displayed antifungal properties against several pathogenic yeasts. Synergistic activity was observed between flocculosin and amphotericin B, and no significant cytotoxicity was demonstrated when tested against human cell lines.

  4. Self-glycolipids modulate dendritic cells changing the cytokine profiles of committed autoreactive T cells.

    Directory of Open Access Journals (Sweden)

    Karsten Buschard

    Full Text Available The impact of glycolipids of non-mammalian origin on autoimmune inflammation has become widely recognized. Here we report that the naturally occurring mammalian glycolipids, sulfatide and β-GalCer, affect the differentiation and the quality of antigen presentation by monocyte-derived dendritic cells (DCs. In response to sulfatide and β-GalCer, monocytes develop into immature DCs with higher expression of HLA-DR and CD86 but lower expression of CD80, CD40 and CD1a and lower production of IL-12 compared to non-modulated DCs. Self-glycolipid-modulated DCs responded to lipopolysaccharide (LPS by changing phenotype but preserved low IL-12 production. Sulfatide, in particular, reduced the capacity of DCs to stimulate autoreactive Glutamic Acid Decarboxylase (GAD65 - specific T cell response and promoted IL-10 production by the GAD65-specific clone. Since sulfatide and β-GalCer induced toll-like receptor (TLR-mediated signaling, we hypothesize that self-glycolipids deliver a (tolerogenic polarizing signal to differentiating DCs, facilitating the maintenance of self-tolerance under proinflammatory conditions.

  5. Iminosugars Inhibit Dengue Virus Production via Inhibition of ER Alpha-Glucosidases-Not Glycolipid Processing Enzymes.

    Science.gov (United States)

    Sayce, Andrew C; Alonzi, Dominic S; Killingbeck, Sarah S; Tyrrell, Beatrice E; Hill, Michelle L; Caputo, Alessandro T; Iwaki, Ren; Kinami, Kyoko; Ide, Daisuke; Kiappes, J L; Beatty, P Robert; Kato, Atsushi; Harris, Eva; Dwek, Raymond A; Miller, Joanna L; Zitzmann, Nicole

    2016-03-01

    It has long been thought that iminosugar antiviral activity is a function of inhibition of endoplasmic reticulum-resident α-glucosidases, and on this basis, many iminosugars have been investigated as therapeutic agents for treatment of infection by a diverse spectrum of viruses, including dengue virus (DENV). However, iminosugars are glycomimetics possessing a nitrogen atom in place of the endocyclic oxygen atom, and the ubiquity of glycans in host metabolism suggests that multiple pathways can be targeted via iminosugar treatment. Successful treatment of patients with glycolipid processing defects using iminosugars highlights the clinical exploitation of iminosugar inhibition of enzymes other than ER α-glucosidases. Evidence correlating antiviral activity with successful inhibition of ER glucosidases together with the exclusion of alternative mechanisms of action of iminosugars in the context of DENV infection is limited. Celgosivir, a bicyclic iminosugar evaluated in phase Ib clinical trials as a therapeutic for the treatment of DENV infection, was confirmed to be antiviral in a lethal mouse model of antibody-enhanced DENV infection. In this study we provide the first evidence of the antiviral activity of celgosivir in primary human macrophages in vitro, in which it inhibits DENV secretion with an EC50 of 5 μM. We further demonstrate that monocyclic glucose-mimicking iminosugars inhibit isolated glycoprotein and glycolipid processing enzymes and that this inhibition also occurs in primary cells treated with these drugs. By comparison to bicyclic glucose-mimicking iminosugars which inhibit glycoprotein processing but do not inhibit glycolipid processing and galactose-mimicking iminosugars which do not inhibit glycoprotein processing but do inhibit glycolipid processing, we demonstrate that inhibition of endoplasmic reticulum-resident α-glucosidases, not glycolipid processing, is responsible for iminosugar antiviral activity against DENV. Our data suggest that

  6. Importance of macrophage cholesterol content on the flux of cholesterol mass

    OpenAIRE

    Sankaranarayanan, Sandhya; de la Llera-Moya, Margarita; Drazul-Schrader, Denise; Asztalos, Bela F.; Weibel, Ginny L.; Rothblat, George H.

    2010-01-01

    Net flux of cholesterol represents the difference between efflux and influx and can result in net cell-cholesterol accumulation, net cell-cholesterol depletion, or no change in cellular cholesterol content. We measured radiolabeled cell-cholesterol efflux and cell-cholesterol mass using cholesterol-normal and -enriched J774 and elicited mouse peritoneal macrophage cells. Net cell-cholesterol effluxes were observed when cholesterol-enriched J774 cells were incubated with 3.5% apolipoprotein (a...

  7. Cholesterol Embolism: An Overlooked Diagnosis

    Directory of Open Access Journals (Sweden)

    Sinem Nihal ESATOĞLU

    2012-01-01

    Full Text Available Acute renal failure following angiography is usually due to radiocontrast nephropathy; however, cholesterol embolism should be kept in mind when making the differential diagnosis. Cholesterol embolism is a multisystem disease, usually seen in elderly men who have severe atherosclerosis. In this case report, we describe a patient with cholesterol embolism who had a typical clinical history of progressive renal failure. We hope that this case report will emphasize the importance of this overlooked syndrome.

  8. Formation of the two novel glycolipid biosurfactants, mannosylribitol lipid and mannosylarabitol lipid, by Pseudozyma parantarctica JCM 11752T.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2012-11-01

    In order to develop novel glycolipid biosurfactants, Pseudozyma parantarctica JCM 11752(T), which is known as a producer of mannosylerythritol lipids (MEL), was cultivated using different sugar alcohols with the presence of vegetable oil. When cultivated in a medium containing 4 % (w/v) olive oil and 4 % D-ribitol or D-arabitol, the yeast strain provided different glycolipids, compared to the case of no sugar alcohol. On TLC, both of the extracted glycolipid fractions gave two major spots corresponding to MEL-A (di-acetylated MEL) and MEL-B (mono-acetylated MEL). Based on (1)H NMR analysis, one glycolipid was identified as MEL-A, but the other was not MEL-B. On high-performance liquid chromatography after acid hydrolysis, the unknown glycolipid from the D-ribitol culture provided mainly two peaks identical to D-mannose and D-ribitol, and the other unknown glycolipid from the D-arabitol culture did two peaks identical to D-mannose and D-arabitol. Accordingly, the two unknown glycolipids were identified as mannosylribitol lipid (MRL) and mannosylarabitol lipid (MAL), respectively. The observed critical micelle concentration (CMC) and surface tension at CMC of MRL were 1.6 × 10(-6) M and 23.7 mN/m, and those of MAL were 1.5 × 10(-6) M and 24.2 mN/m, respectively. These surface-tension-lowering activities were significantly higher compared to conventional MEL. Furthermore, on a water-penetration scan, MRL and MAL efficiently formed not only the lamella phase (L(α)) but also the myelins at a wide range of concentrations, indicating their excellent self-assembling properties and high hydrophilicity. The present two glycolipids should thus facilitate the application of biosurfactants as new functional materials. PMID:22722912

  9. Genome Sequence of the Basidiomycetous Yeast Pseudozyma antarctica T-34, a Producer of the Glycolipid Biosurfactants Mannosylerythritol Lipids.

    Science.gov (United States)

    Morita, Tomotake; Koike, Hideaki; Koyama, Yoshinori; Hagiwara, Hiroko; Ito, Emi; Fukuoka, Tokuma; Imura, Tomohiro; Machida, Masayuki; Kitamoto, Dai

    2013-01-01

    The basidiomycetous yeast Pseudozyma antarctica T-34 is an excellent producer of mannosylerythritol lipids (MELs), members of the multifunctional extracellular glycolipids, from various feedstocks. Here, the genome sequence of P. antarctica T-34 was determined and annotated. Analysis of the sequence might provide insights into the properties of this yeast that make it superior for use in the production of functional glycolipids, leading to the further development of P. antarctica for industrial applications. PMID:23558529

  10. Reducing Cholesterol Intake: Are the recommendations valid?

    OpenAIRE

    Chan, Joanna K.; McDonald, Bruce E.

    1991-01-01

    The authors question dietary recommendations for the general public calling for reduced cholesterol intake. Metabolic studies have shown that dietary cholesterol normally induces only small increases in blood cholesterol level. There is evidence that only a portion of the population responds to a change in cholesterol intake; hence lowering dietary cholesterol will be effective for only some.

  11. Antimycobacterial action of a new glycolipid-peptide complex obtained from extracellular metabolites of Raoultella ornithinolytica.

    Science.gov (United States)

    Fiołka, Marta J; Grzywnowicz, Krzysztof; Mendyk, Ewaryst; Zagaja, Mirosław; Szewczyk, Rafał; Rawski, Michał; Keller, Radosław; Rzymowska, Jolanta; Wydrych, Jerzy

    2015-12-01

    In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microscopic techniques. The cells lost their shape, stuck together and formed clusters. Surface-enhanced Raman spectroscopy analysis showed that, after incubation, the complex was attached to the cell walls of the Mycobacterium. Analyses of the component performed with Fourier transform infrared spectroscopy demonstrated high similarity to a bacteriocin nisin, but energy dispersive X-ray spectroscopy analysis revealed differences in the elemental composition of this antimicrobial peptide. The component with antimycobacterial activity was identified using mass spectrometry techniques as a glycolipid-peptide complex. As it exhibits no cytotoxicity on normal human fibroblasts, the glycolipid-peptide complex appears to be a promising compound for investigations of its activity against pathogenic mycobacteria. PMID:26547373

  12. Formation of W/O microemulsion based on natural glycolipid biosurfactant, mannosylerythritol lipid-a.

    Science.gov (United States)

    Worakitkanchanakul, Wannasiri; Imura, Tomohiro; Morita, Tomotake; Fukuoka, Tokuma; Sakai, Hideki; Abe, Masahiko; Rujiravanit, Ratana; Chavadej, Sumaeth; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipid-A (MEL-A) is a glycolipid biosurfactant abundantly produced from soybean oil by microorganisms at a yield of up to 100 g/L. In this study, the formation of water-in-oil (W/O) microemulsion based on the single component of MEL-A was confirmed using dynamic light scattering (DLS) and freeze fracture electron microscopy (FF-EM). DLS and FF-EM measurements revealed that the diameter of the microemulsion increases with an increase in water-to-surfactant mole ratio (W(0)) ranging from 20 to 60 nm, and the maximum W(0) value was found to be 20, which is as high as that of soybean lecithin. Glycolipid biosurfactant has a great potential for the formation of W/O microemulsion without using any cosurfactants. PMID:18075224

  13. Production of glycolipid biosurfactants, mannosylerythritol lipids, by a smut fungus, Ustilago scitaminea NBRC 32730.

    Science.gov (United States)

    Morita, Tomotake; Ishibashi, Yuko; Fukuoka, Tokuma; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2009-03-23

    A smut fungus Ustilago scitaminea NBRC 32730 on sugar cane (Saccharum) was found to accumulate a large amount of glycolipids in the culture medium. As a result of structural characterization, the main glycolipid was identified as MEL-B, 4-O-beta-(2',3'-di-O-alka(e)noyl-6'-O-acetyl-D-mannopyranosyl)-erythritol. The MEL-B was sufficiently produced from a variety of sugars such as sucrose, glucose, fructose, and mannose. Olive oil and methyl oleate were also available as carbon sources to produce MEL-B. However, these residual oils made product recovery very complicated. Under optimal conditions, a maximum MEL yield of 12.8 g/l was achieved by feeding of sucrose. PMID:19270362

  14. Inhibition of pancreatic cholesterol esterase reduces cholesterol absorption in the hamster

    OpenAIRE

    Heidrich, John E.; Contos, Linda M; Hunsaker, Lucy A; Deck, Lorraine M.; Vander Jagt, David L.

    2004-01-01

    Background Pancreatic cholesterol esterase has three proposed functions in the intestine: 1) to control the bioavailability of cholesterol from dietary cholesterol esters; 2) to contribute to incorporation of cholesterol into mixed micelles; and 3) to aid in transport of free cholesterol to the enterocyte. Inhibitors of cholesterol esterase are anticipated to limit the absorption of dietary cholesterol. Results The selective and potent cholesterol esterase inhibitor 6-chloro-3-(1-ethyl-2-cycl...

  15. Extension of the GLYCAM06 Biomolecular Force Field to Lipids, Lipid Bilayers and Glycolipids

    OpenAIRE

    Tessier, Matthew B; DeMarco, Mari L.; Yongye, Austin B.; Woods, Robert J.

    2008-01-01

    GLYCAM06 is a generalisable biomolecular force field that is extendible to diverse molecular classes in the spirit of a small-molecule force field. Here we report parameters for lipids, lipid bilayers and glycolipids for use with GLYCAM06. Only three lipid-specific atom types have been introduced, in keeping with the general philosophy of transferable parameter development. Bond stretching, angle bending, and torsional force constants were derived by fitting to quantum mechanical data for a c...

  16. Decay accelerating factor (DAF) is anchored to membranes by a C-terminal glycolipid

    International Nuclear Information System (INIS)

    Purified 70 kDa membrane (m) DAF incorporates into cells when added in vitro. A 2 kDa smaller DAF form which functions extrinsically like C4bp but is unable to incorporate can be isolated from urine (u). Because of common deficits of mDAF and acetylcholinesterase (AChE) in erythrocytes (E) of patients with paroxysmal nocturnal hemoglobinuria (PNH), mDAF was analyzed for a O-terminal glycolipid membrane anchor similar to that in E AChE. Incubation of E with phosphatidylinositol-specific phospholipase C, an enzyme which cleaves a similar glycolipid anchor in trypanosome variant surface glycoproteins (mfVSGs), released 20% of the DAF antigen. The released DAF species resembled uDAF in size, extrinsic model of C4b2a decay, and lack of hydrophobicity. Reductive radiomethylation of mDAF with [14C]HCHO and NaCNBH3 revealed ethanolamine and glucosamine in proportions similar to those in the E AChE glycolipid anchor. Papain cleavage of radiomethylated mDAF released the labeled ethanolamine and glucosamine in small O-terminal fragments from the residual DAF that retained N-terminal Asp. Following labeling of the anchors of mDAF and E AChE with the lipophilic photoreagent 3-trifluoromethyl-3-(m-[125I]iodophenyl)diazirine, cleavage at the glucosamine residue by deamination quantitatively released the label from both proteins. Biosynthetic labeling of Hela cells with [3H]ethanolamine resulted in rapid 3H incorporation into both 48 kDa proDAF and 70 kDa mDAF. These data indicate that mDAF is anchored by a glycolipid similar to that in E AChE, mfVSGs and Thy-1 antigen and raise the possibility that a defect in the assembly or attachment of this structure could account for the deficits of mDAF and E AChE in PNH

  17. Anchors away: contribution of a glycolipid anchor to bacterial invasion of host cells

    OpenAIRE

    Baron, Miriam J.; Kasper, Dennis L.

    2005-01-01

    Group B Streptococcus (GBS) is an important cause of infections, including meningitis. The molecular events underlying its pathogenesis are poorly understood. A study in this issue of the JCI reports that the GBS invasion-associated gene (iagA) contributes to meningeal infection and virulence by facilitating invasion of the cells that compose the blood-brain barrier and of other host cells. The mechanism involved most likely relates to the gene product’s role in synthesis of a glycolipid anch...

  18. A glycolipid-anchored prion protein is endocytosed via clathrin-coated pits

    OpenAIRE

    1994-01-01

    The cellular prion protein (PrPc) is a glycolipid-anchored, cell surface protein of unknown function, a posttranslationally modified isoform of which PrPSc is involved in the pathogenesis of Creutzfeldt- Jakob disease, scrapie, and other spongiform encephalopathies. We have shown previously that chPrP, a chicken homologue of mammalian PrPC, constitutively cycles between the cell surface and an endocytic compartment, with a transit time of approximately 60 min in cultured neuroblastoma cells. ...

  19. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    Science.gov (United States)

    Im, Jae Hong; Nakane, Takashi; Yanagishita, Hiroshi; Ikegami, Toru; Kitamoto, Dai

    2001-01-01

    Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand for immunoglobulins, and undertook the investigation on the binding between mannosylerythritol lipid A (MEL-A) and human immunoglobulin G (HIgG). Results In ELISA assay, MEL-A showed nearly the same binding affinity towards HIgG as that of bovine ganglioside GM1. Fab of human IgG was considered to play a more important role than Fc in the binding of HIgG by MEL-A. The bound amount of HIgG increased depending on the attached amount of MEL-A onto poly (2-hydroxyethyl methacrylate) (polyHEMA) beads, whereas the amount of human serum albumin slightly decreased. Binding-amount and -selectivity of HIgG towards MEL-A were influenced by salt species, salt concentration and pH in the buffer solution. The composite of MEL-A and polyHEMA, exhibited a significant binding constant of 1.43 × 106 (M-1) for HIgG, which is approximately 4-fold greater than that of protein A reported. Conclusions MEL-A shows high binding-affinity towards HIgG, and this is considered to be due to "multivalent effect" based on the binding molar ratio. This is the first report on the binding of a natural human antibody towards a yeast glycolipid. PMID:11604104

  20. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    Directory of Open Access Journals (Sweden)

    Ikegami Toru

    2001-09-01

    Full Text Available Abstract Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand for immunoglobulins, and undertook the investigation on the binding between mannosylerythritol lipid A (MEL-A and human immunoglobulin G (HIgG. Results In ELISA assay, MEL-A showed nearly the same binding affinity towards HIgG as that of bovine ganglioside GM1. Fab of human IgG was considered to play a more important role than Fc in the binding of HIgG by MEL-A. The bound amount of HIgG increased depending on the attached amount of MEL-A onto poly (2-hydroxyethyl methacrylate (polyHEMA beads, whereas the amount of human serum albumin slightly decreased. Binding-amount and -selectivity of HIgG towards MEL-A were influenced by salt species, salt concentration and pH in the buffer solution. The composite of MEL-A and polyHEMA, exhibited a significant binding constant of 1.43 × 106 (M-1 for HIgG, which is approximately 4-fold greater than that of protein A reported. Conclusions MEL-A shows high binding-affinity towards HIgG, and this is considered to be due to "multivalent effect" based on the binding molar ratio. This is the first report on the binding of a natural human antibody towards a yeast glycolipid.

  1. Epigenetic Regulation of Cholesterol Homeostasis

    Directory of Open Access Journals (Sweden)

    Steve eMeaney

    2014-09-01

    Full Text Available Although best known as a risk factor for cardiovascular disease, cholesterol is a vital component of all mammalian cells. In addition to key structural roles, cholesterol is a vital biochemical precursor for numerous biologically important compounds including oxysterols and bile acids, as well as acting as an activator of critical morphogenic systems (e.g. the Hedgehog system. A variety of sophisticated regulatory mechanisms interact to coordinate the overall level of cholesterol in cells, tissues and the entire organism. Accumulating evidence indicates that in additional to the more ‘traditional’ regulatory schemes, cholesterol homeostasis is also under the control of epigenetic mechanisms such as histone acetylation and DNA methylation. The available evidence supporting a role for these mechanisms in the control of cholesterol synthesis, elimination, transport and storage are the focus of this review.

  2. Isolation of two glycolipid transfer proteins from bovine brain: reactivity toward gangliosides and neutral glycosphingolipids

    International Nuclear Information System (INIS)

    Two glycolipid transfer proteins that catalyze the transfer of gangliosides and neutral glycosphingolipids from phosphatidylcholine vesicles to erythrocyte ghosts have been isolated from calf brain. Purification procedures included differential centrifugation, precipitation at pH 5.1, ammonium sulfate precipitation, and gel filtration on Sephadex G-50 and G-75. The final stage employed fast protein liquid chromatography (Mono S), producing two peaks of activity. Apparent purity of the major peak (TP I) was approximately 85-90%, as judged by sodium dodecyl sulfate/urea-polyacrylamide gel electrophoresis. Radiolabeled glycolipids were used in the analysis. That of the minor fraction (TP II) was less. The major band of both fractions had a molecular mass of approximately 20,000 daltons. Both proteins catalyzed the transfer of ganglioside GM1 as well as asialo-GM1, but transfer protein I was more effective with di- and trisialogangliosides. Transfer protein II appeared to be somewhat more specific for neutral glycolipids in that GA1 was transferred more rapidly than any of the gangliosides; however, lactosylceramide transfer was relatively slow. Neither protein catalyzed transfer of phosphatidylcholine

  3. Fossilized glycolipids reveal past oceanic N2 fixation by heterocystous cyanobacteria.

    Science.gov (United States)

    Bauersachs, Thorsten; Speelman, Eveline N; Hopmans, Ellen C; Reichart, Gert-Jan; Schouten, Stefan; Damsté, Jaap S Sinninghe

    2010-11-01

    N(2)-fixing cyanobacteria play an essential role in sustaining primary productivity in contemporary oceans and freshwater systems. However, the significance of N(2)-fixing cyanobacteria in past nitrogen cycling is difficult to establish as their preservation potential is relatively poor and specific biological markers are presently lacking. Heterocystous N(2)-fixing cyanobacteria synthesize unique long-chain glycolipids in the cell envelope covering the heterocyst cell to protect the oxygen-sensitive nitrogenase enzyme. We found that these heterocyst glycolipids are remarkably well preserved in (ancient) lacustrine and marine sediments, unambiguously indicating the (past) presence of N(2)-fixing heterocystous cyanobacteria. Analysis of Pleistocene sediments of the eastern Mediterranean Sea showed that heterocystous cyanobacteria, likely as epiphytes in symbiosis with planktonic diatoms, were particularly abundant during deposition of sapropels. Eocene Arctic Ocean sediments deposited at a time of large Azolla blooms contained glycolipids typical for heterocystous cyanobacteria presently living in symbiosis with the freshwater fern Azolla, indicating that this symbiosis already existed in that time. Our study thus suggests that heterocystous cyanobacteria played a major role in adding "new" fixed nitrogen to surface waters in past stratified oceans. PMID:20966349

  4. Effects of metformin and sitagliptin on glycolipid metabolism in type 2 diabetic rats on different diets

    Science.gov (United States)

    Yang, Juhong; Ba, Tu; Chen, Liming; Shan, Chunyan; Zheng, Miaoyan; Wang, Ying; Ren, Huizhu; Chen, Jingli; Xu, Jie; Han, Fei; Zhang, Yi; Yang, Xiaoyun

    2016-01-01

    Introduction The aim of the study was to investigate the effects of metformin and sitagliptin on glycolipid metabolism in type 2 diabetes after different diets. Material and methods Seventy Male Sprague Dawley rats were fed with a high fat diet followed by streptozotocin treatment to induce type 2 diabetes. Then all rats were randomly divided into a control group, a metformin group (200 mg/kg), and a sitagliptin group (10 mg/kg). Each group was further divided into 4 groups receiving one load of high carbohydrate diet (45% glucose, 4.5 ml/kg), high fat diet (20% lipid emulsion, 4.5 ml/kg), high protein diet (20% whey protein, 10 ml/kg) or mixed meal, respectively. The caloric densities were all 33 kJ/kg. Postprandial blood glucose (P2BG), triglyceride (TG), glucagon-like peptide-1 (GLP-1), glucagon and insulin levels were measured. Results In the high carbohydrate group, sitagliptin was more efficient in lowering P2BG compared with metformin (p 0.05), although it did reduce the TG level (p 0.05) compared with sitagliptin. Conclusions In the type 2 diabetic model, metformin and sitagliptin have different effects on glycolipid metabolism after different diets. If it is proved in type 2 diabetic patients, then different medicines may be recommended according to different diets in order to improve glycolipid metabolism.

  5. Understand Your Risk for High Cholesterol

    Science.gov (United States)

    ... Resources Stroke More Understand Your Risk for High Cholesterol Updated:Apr 1,2016 LDL (bad) cholesterol is ... content was last reviewed on 04/21/2014. Cholesterol Guidelines: Putting the pieces together Myth vs. Truth – ...

  6. Overview of Cholesterol and Lipid Disorders

    Science.gov (United States)

    ... Medical Dictionary Additional Content Medical News Overview of Cholesterol and Lipid Disorders By Anne Carol Goldberg, MD ... Version. DOCTORS: Click here for the Professional Version Cholesterol Disorders Overview of Cholesterol and Lipid Disorders Dyslipidemia ...

  7. Cholesterol - what to ask your doctor

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000211.htm Cholesterol - what to ask your doctor To use the ... this page, please enable JavaScript. Your body needs cholesterol to work properly. When you have extra cholesterol ...

  8. Production of glycolipid biosurfactants, mannosylerythritol lipids, by Pseudozyma siamensis CBS 9960 and their interfacial properties.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2008-05-01

    The search for a novel producer of glycolipid biosurfactants, mannosylerythritol lipids (MELs), was undertaken on the basis of the analysis of ribosomal DNA sequences of yeast strains of the genus Pseudozyma. In the course of the investigation, Pseudozyma siamensis CBS 9960, which is closely related to Pseudozyma shanxiensis, a known MEL-C producer but with a different morphology, was found to accumulate a large amount of glycolipids. On thin layer chromatography, the extracellular glycolipids showed nearly the same spots as those of the MELs produced by P. shanxiensis. However, the result of high-performance liquid chromatography analysis revealed that the present strain has a much higher glycolipid production yield than P. shanxiensis. From the structural characterization by (1)H and (13)C NMR, the major glycolipid (more than 84% of the total) was identified as a mixture of 4-O-[(2',4'-di-O-acetyl-3'-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol and 4-O-[(4'-O-acetyl-3'-O-alka(e)noyl-2'-O-butanoyl)-beta-D-mannopyranosyl]-D-erythritol, both of which are types of MEL-C. The present MEL-C possessed a short-chain acid (C(2) or C(4)) at the C-2' position and a long-chain acid (C(16)) at the C-3' position of the mannose moiety, and thus, the hydrophobic part was considerably different from that of conventional MELs, which mainly possess two medium-chain acids (C(10)) at the C-2' and C-3' positions. Under optimal growth conditions with safflower oil in a shake culture, the total amount of MELs reached approximately 19 g/l after 9 d at 25 degrees C. We further investigated the interfacial properties of the present MEL-C, considering its unique hydrophobic structure. The observed critical micelle concentration (CMC) and the surface tension at the CMC of the MEL were 4.5 x 10(-6) M and 30.7 mN/m, respectively. In addition, on a water penetration scan, the MEL efficiently formed the liquid crystal phases such as hexagonal (H) and lamella (L(a)) at a wide range of

  9. A relation between high-density-lipoprotein cholesterol and bile cholesterol saturation.

    OpenAIRE

    Thornton, J R; Heaton, K. W.; Macfarlane, D G

    1981-01-01

    The association of cholesterol gall stones with coronary artery disease is controversial. To investigate this possible relation at the biochemical level, bile cholesterol saturation and the plasma concentrations of triglycerides, total cholesterol, and high-density-lipoprotein cholesterol (HDL cholesterol) were measured in 25 healthy, middle-aged women. Bile cholesterol saturation index was negatively correlated with HDL cholesterol. It was positively correlated with plasma triglycerides and ...

  10. Imaging appearances of cholesterol pneumonia

    International Nuclear Information System (INIS)

    Objection: To analyze the imaging appearances of cholesterol pneumonia. Methods We retrospectively analyzed the X-ray and CT findings of 3 patients with cholesterol pneumonia confirmed pathologically and reviewed correlative literature. Results: Lesions similar to mass were found in X-ray and CT imaging of three cases. Two of them appeared cavity with fluid-level and one showed multiple ring enhancement after CT contrast. The course of disease was very. long and it had no respond to antibiotic therapy. Amounts of foam cells rich in cholesterol crystal were detected in pathological examination. Conclusions: Cholesterol pneumonia is a rare chronic pulmonary idiopathic disease, and the radiological findings can do some help to its diagnosis. (authors)

  11. Cholesterol's location in lipid bilayers.

    Science.gov (United States)

    Marquardt, Drew; Kučerka, Norbert; Wassall, Stephen R; Harroun, Thad A; Katsaras, John

    2016-09-01

    It is well known that cholesterol modifies the physical properties of lipid bilayers. For example, the much studied liquid-ordered Lo phase contains rapidly diffusing lipids with their acyl chains in the all trans configuration, similar to gel phase bilayers. Moreover, the Lo phase is commonly associated with cholesterol-enriched lipid rafts, which are thought to serve as platforms for signaling proteins in the plasma membrane. Cholesterol's location in lipid bilayers has been studied extensively, and it has been shown - at least in some bilayers - to align differently from its canonical upright orientation, where its hydroxyl group is in the vicinity of the lipid-water interface. In this article we review recent works describing cholesterol's location in different model membrane systems with emphasis on results obtained from scattering, spectroscopic and molecular dynamics studies. PMID:27056099

  12. Cholesterol confusion and statin controversy.

    Science.gov (United States)

    DuBroff, Robert; de Lorgeril, Michel

    2015-07-26

    The role of blood cholesterol levels in coronary heart disease (CHD) and the true effect of cholesterol-lowering statin drugs are debatable. In particular, whether statins actually decrease cardiac mortality and increase life expectancy is controversial. Concurrently, the Mediterranean diet model has been shown to prolong life and reduce the risk of diabetes, cancer, and CHD. We herein review current data related to both statins and the Mediterranean diet. We conclude that the expectation that CHD could be prevented or eliminated by simply reducing cholesterol appears unfounded. On the contrary, we should acknowledge the inconsistencies of the cholesterol theory and recognize the proven benefits of a healthy lifestyle incorporating a Mediterranean diet to prevent CHD. PMID:26225201

  13. Evolutionary constrained optimization

    CERN Document Server

    Deb, Kalyanmoy

    2015-01-01

    This book makes available a self-contained collection of modern research addressing the general constrained optimization problems using evolutionary algorithms. Broadly the topics covered include constraint handling for single and multi-objective optimizations; penalty function based methodology; multi-objective based methodology; new constraint handling mechanism; hybrid methodology; scaling issues in constrained optimization; design of scalable test problems; parameter adaptation in constrained optimization; handling of integer, discrete and mix variables in addition to continuous variables; application of constraint handling techniques to real-world problems; and constrained optimization in dynamic environment. There is also a separate chapter on hybrid optimization, which is gaining lots of popularity nowadays due to its capability of bridging the gap between evolutionary and classical optimization. The material in the book is useful to researchers, novice, and experts alike. The book will also be useful...

  14. to HDL-cholesterol functionality

    Directory of Open Access Journals (Sweden)

    Malara Marzena

    2016-05-01

    Full Text Available The purpose of this study was to analyse the scientific evidence concerning the effects of two enzymes – paraoxonase 1 and myeloperoxidase – on the functions of HDL-cholesterol. It is well documented that disturbed circulating lipoproteins (a high total and high LDL-cholesterol, and low HDL-cholesterol bring about atherosclerosis and an increased risk of cardiovascular disease (CVD which is recognised as the main cause of death all around the world. In consequence, numerous studies have focused on procedures which will improve the plasma lipoproteins profile by decreasing the total cholesterol and the LDL-cholesterol (LDL-C and increasing the HDL-cholesterol (HDL-C. However, the anti-atherogenic role of HDL-C has been challenged in studies showing that genetically elevated HDL-cholesterol does not offer protection against CVD. Moreover, it has been found that raising the circulating HDL-cholesterol fails to reduce atherosclerosis. The doubts concerning the protective role of HDL-C have been supported by in vitro studies which indicate that the HDL-C from patients with atherosclerosis does not have a protective action, but does stimulate inflammation and free radical synthesis. The above data suggests that HDL-C, commonly recognised as protective against atherosclerosis, in some circumstances becomes pro-atherogenic, and is thus dysfunctional. Our review focuses on two enzymes – paraoxonase 1 (PON1 and myeloperoxidase (MPO – which markedly affect the properties of HDL-C and contribute to its anti – or pro-atherogenic activity. Moreover, the effects of the diet and physical activity on PON1 and MPO are summarised with respect to the HDL-C functionality.

  15. Cholesterol Worships a New Idol

    Institute of Scientific and Technical Information of China (English)

    Ira G. Schulman

    2009-01-01

    The growing worldwide epidemic of cardiovascular disease suggests that new therapeutic strategies are needed to complement statins in the lowering of cholesterol levels. In a recent paper in Science, Tontonoz and colleagues have identified Idol as a protein that can control cholesterol levels by regulating the stability of the low-density lipoprotein receptor; inhibiting the activity of Idol could provide novel approaches for the treatment of cardiovascular disease.

  16. Identification of Ustilago cynodontis as a new producer of glycolipid biosurfactants, mannosylerythritol lipids, based on ribosomal DNA sequences.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipids (MELs) are one of the most promising glycolipid biosurfactants known because of their multifunctionality and biocompatibility. The search for novel producers of MELs was undertaken based on the analysis of ribosomal DNA sequences on basidiomycetous yeasts. The bermuda grass smut fungus Ustilago cynodontis NBRC 7530, which taxonomically relates to Pseudozyma shanxiensis known as a MEL-C producer, was found to accumulate glycolipids in the cultured medium. Under a shake flask culture with soybean oil, the amount of the glycolipids was 1.4 g/L for 7 days at 25 degrees C. As a result of the structural characterization, the main glycolipids was identified as 4-O-[(4'-O-acetyl-3'-O-alka(e)noyl-2'-O-butanoyl)-beta-D-mannopyranosyl]-D-erythritol, and the major fatty acids were C(14) and C(16) ones. The glycolipid was highly hydrophilic MEL-C, and very similar to those produced by P. shanxiensis. The fungi of the genus Ustilago are thus likely to be potential producers of MELs as well as the yeasts of the genus Pseudozyma. PMID:18781055

  17. Glycolipid precursors for the membrane anchor of Trypanosoma brucei variant surface glycoproteins. II. Lipid structures of phosphatidylinositol-specific phospholipase C sensitive and resistant glycolipids

    International Nuclear Information System (INIS)

    A common diagnostic feature of glycosylinositol phospholipid (GPI)-anchored proteins is their release from the membrane by a phosphatidylinositol-specific phospholipase C (PI-PLC). However, some GPI-anchored proteins are resistant to this enzyme. The best characterized example of this subclass is the human erythrocyte acetylcholinesterase, where the structural basis of PI-PLC resistance has been shown to be the acylation of an inositol hydroxyl group(s). Both PI-PLC-sensitive and resistant GPI-anchor precursors (P2 and P3, respectively) have been found in Trypanosoma brucei, where the major surface glycoprotein is anchored by a PI-PLC-sensitive glycolipid anchor. The accompanying paper shows that P2 and P3 have identical glycans, indistinguishable from the common core glycan found on all the characterized GPI protein anchors. This paper shows that the single difference between P2 and P3, and the basis for the PI-PLC insusceptibility of P3, is a fatty acid, ester-linked to the inositol residue in P3. The inositol-linked fatty acid can be removed by treatment with mild base to restore PI-PLC sensitivity. Biosynthetic labeling experiments with [3H]palmitic acid and [3H]myristic acid show that [3H]palmitic acid specifically labels the inositol residue in P3 while [3H]myristic acid labels the diacylglycerol portion. Possible models to account for the simultaneous presence of PI-PLC-resistant and sensitive glycolipids are discussed in the context of available information on the biosynthesis of GPI-anchors

  18. Constraining Galileon inflation

    Energy Technology Data Exchange (ETDEWEB)

    Regan, Donough; Anderson, Gemma J.; Hull, Matthew; Seery, David, E-mail: D.Regan@sussex.ac.uk, E-mail: G.Anderson@sussex.ac.uk, E-mail: Matthew.Hull@port.ac.uk, E-mail: D.Seery@sussex.ac.uk [Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom)

    2015-02-01

    In this short paper, we present constraints on the Galileon inflationary model from the CMB bispectrum. We employ a principal-component analysis of the independent degrees of freedom constrained by data and apply this to the WMAP 9-year data to constrain the free parameters of the model. A simple Bayesian comparison establishes that support for the Galileon model from bispectrum data is at best weak.

  19. Cholesterol and benign prostate disease.

    Science.gov (United States)

    Freeman, Michael R; Solomon, Keith R

    2011-01-01

    The origins of benign prostatic diseases, such as benign prostatic hyperplasia (BPH) and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), are poorly understood. Patients suffering from benign prostatic symptoms report a substantially reduced quality of life, and the relationship between benign prostate conditions and prostate cancer is uncertain. Epidemiologic data for BPH and CP/CPPS are limited, however an apparent association between BPH symptoms and cardiovascular disease (CVD) has been consistently reported. The prostate synthesizes and stores large amounts of cholesterol and prostate tissues may be particularly sensitive to perturbations in cholesterol metabolism. Hypercholesterolemia, a major risk factor for CVD, is also a risk factor for BPH. Animal model and clinical trial findings suggest that agents that inhibit cholesterol absorption from the intestine, such as the class of compounds known as polyene macrolides, can reduce prostate gland size and improve lower urinary tract symptoms (LUTS). Observational studies indicate that cholesterol-lowering drugs reduce the risk of aggressive prostate cancer, while prostate cancer cell growth and survival pathways depend in part on cholesterol-sensitive biochemical mechanisms. Here we review the evidence that cholesterol metabolism plays a role in the incidence of benign prostate disease and we highlight possible therapeutic approaches based on this concept. PMID:21862201

  20. Formation of Cholesterol Bilayer Domains Precedes Formation of Cholesterol Crystals in Cholesterol/Dimyristoylphosphatidylcholine Membranes: EPR and DSC Studies

    OpenAIRE

    Mainali, Laxman; Raguz, Marija; Subczynski, Witold K.

    2013-01-01

    Saturation-recovery EPR along with DSC were used to determine the cholesterol content at which pure cholesterol bilayer domains (CBDs) and cholesterol crystals begin to form in dimyristoylphosphatidylcholine (DMPC) membranes. To preserve compositional homogeneity throughout the membrane suspension, lipid multilamellar dispersions were prepared using a rapid solvent exchange method. The cholesterol content increased from 0 to 75 mol%. With spin-labeled cholesterol analogs it was shown that the...

  1. Phosphatidylcholine: Greasing the Cholesterol Transport Machinery

    Science.gov (United States)

    Lagace, Thomas A.

    2015-01-01

    Negative feedback regulation of cholesterol metabolism in mammalian cells ensures a proper balance of cholesterol with other membrane lipids, principal among these being the major phospholipid phosphatidylcholine (PC). Processes such as cholesterol biosynthesis and efflux, cholesteryl ester storage in lipid droplets, and uptake of plasma lipoproteins are tuned to the cholesterol/PC ratio. Cholesterol-loaded macrophages in atherosclerotic lesions display increased PC biosynthesis that buffers against elevated cholesterol levels and may also facilitate cholesterol trafficking to enhance cholesterol sensing and efflux. These same mechanisms could play a generic role in homeostatic responses to acute changes in membrane free cholesterol levels. Here, I discuss the established and emerging roles of PC metabolism in promoting intracellular cholesterol trafficking and membrane lipid homeostasis. PMID:27081313

  2. Effect of glycolipids of Leishmania parasites on human monocyte activity. Inhibition by lipophosphoglycan.

    Science.gov (United States)

    Frankenburg, S; Leibovici, V; Mansbach, N; Turco, S J; Rosen, G

    1990-12-15

    Lipophosphoglycan (LPG) and glycosyl phosphatidylinositol Ag (GPI), are glycolipids present on the membrane of Leishmania parasites. Both glycolipids have been chemically characterized. LPG is a polysaccharide of repeating phosphorylated units linked to a phosphocarbohydrate core that is anchored to the membrane by lysoalkyl phosphatidylinositol (PI). The GPI are smaller glycolipids with a structure resembling the phosphocarbohydrate core of the LPG. They are anchored to the membrane by alkyl acyl PI. Their relative abundance, uniqueness of structure, and cellular location suggest a role in interactions of the parasites with host cells. In the present study we examined the effect of LPG and GPI on the activation of human peripheral blood monocytes. Three parameters were studied: the production of IL-1, chemotactic locomotion, and oxidative burst. We found that whereas neither GPI nor LPG directly affected monocyte activity, preincubation of the monocytes with LPG strongly inhibited further activation: The production of IL-1, after stimulation with LPS, was decreased in a dose-dependent manner. Previous incubation with LPG also inhibited chemotactic locomotion of monocytes and neutrophils in response to diacylglycerol, zymosan-activated serum, FMLP and LTB4. Luminol-dependent chemiluminiscence caused by stimulation of the monocytes with streptococci and histone was also inhibited. After fragmentation of the LPG into phosphoglycan and 1-O-alkylglycerol by phosphatidylinositol-phospholipase C, only the phosphoglycan retained inhibitory activity. No difference in inhibitory activity was found between LPG prepared from Leishmania major or Leishmania donovani promastigotes. These results show that the phosphoglycan of LPG inhibits the immunologic response of normal human monocytes and neutrophils, and suggest that LPG may influence the nature of the inflammatory response surrounding infected cells. PMID:2147940

  3. EVALUATION OF GLYCOLIPIDS OF SOME EGYPTIAN MARINE ALGAE AS A SOURCE OF BIOACTIVE SUBSTANCES

    Directory of Open Access Journals (Sweden)

    El Baroty Gamal S

    2011-03-01

    Full Text Available Glycolipids in five species of marine algae: two species of Rhodophyta (Laurencia popillose, Galaxoura cylindriea; and one species of Chlorophyta (Ulva fasciata, and two species of Phaeophyta (Dilophys fasciola, Taonia atomaria collected from Red and Mediterranean sea, respectively were extracted, purified on silica gel column chromatography and identified by liquid chromatography MS/MS. Total glycolipid contents (GL (as % of total lipid were found to be in ranges 10.9 to 28.7%. T. atomaria had the highest level (28.7% followed by L. popillose (22.5 %. GL groups were analyzed for their sugars and fatty acids composition, and the result showed that the highest carbohydrate content of GLs were found in U. fasciata (6.05% and L. popillose (5.8%, and characterized by high content of monosaccharide: mannouronic acid, galactose and rhamnose. Amongst of the glycolipids of algal species, the most predominate fatty acid identified by GC were palmatic (C16:0 19.20 - 65.89% of total fatty acid, ecosatrienoic (C20:3 7.52 - 54.41%. GL analyzed by LC/MS/MS, revealed the peak at m/z 956 corresponding to the molecular formula of C51H104O17 was the most abundant molecular ion among all GLs of algal species and its fragments peaks at m/z 617(C37H58O4 and m/z 337 (C21H58O3, were tentatively identified as digalactosyldiacylglycerol (DGDG. The in vitro anticancer, antimicrobial, and antiviral activities of algal glycolipids were evaluated. GL of all algae species showed a remarkable antiviral activity in dose dependent manner. GL from D. fasciola has shown the most potent effect against HSV1 (IC50 of 10 µg/ml, comparable to that of the current antiviral drug acyclovir (IC50 55 µg/ml. On the other hand, GL of all algal species possessed a moderate antimicrobial activity. GL of T. atomaria exhibited a high inhibition effects against all test microorganisms, with MIC value ranged from 60 to 80 µg/ml. Moreover, all algal GL exhibited remarkable anticancer activities

  4. Alteration of glycolipids in ras-transfected NIH 3T3 cells

    International Nuclear Information System (INIS)

    Glycosphingolipid alterations upon viral transformation are well documented. Transformation of mouse 3T3 cells with murine sarcoma viruses results in marked decreases in the levels of gangliosides GM1 and GD1a and an increase in gangliotriaosylceramide. The transforming oncogenes of these viruses have been identified as members of the ras gene family. The authors analyzed NIH 3T3 cells transfected with human H-, K- and N-ras oncogenes for their glycolipid composition and expression of cell surface gangliosides. Using conventional thin-layer chromatographic analysis, they found that the level of GM3 was increased and that of GD1a was slightly decreased or unchanged, and GM1 was present but not in quantifiable levels. Cell surface levels of GM1 were determined by 125I-labeled cholera toxin binding to intact cells. GD1a was determined by cholera toxin binding to cells treated with sialidase prior to toxin binding. All ras-transfected cells had decreased levels of surface GM1 and GD1 as compared to logarithmically growing normal NIH 3T3 cells. Levels of GM1 and, to a lesser extent, GD1a increased as the latter cells became confluent. Using a monoclonal antibody assay, they found that gangliotriaosylceramide was present in all ras-transfected cells studied but not in logarithmically growing untransfected cells. These results indicated that ras oncogenes derived form human tumors are capable of inducing alterations in glycolipid composition

  5. Isolation of two glycolipid transfer proteins from bovine brain: reactivity toward gangliosides and neutral glycosphingolipids.

    Science.gov (United States)

    Gammon, C M; Vaswani, K K; Ledeen, R W

    1987-09-22

    Two glycolipid transfer proteins that catalyze the transfer of gangliosides and neutral glycosphingolipids from phosphatidylcholine vesicles to erythrocyte ghosts have been isolated from calf brain. Purification procedures included differential centrifugation, precipitation at pH 5.1, ammonium sulfate precipitation, and gel filtration on Sephadex G-50 and G-75. The final stage employed fast protein liquid chromatography (Mono S), producing two peaks of activity. Apparent purity of the major peak (TP I) was approximately 85-90%, as judged by sodium dodecyl sulfate/urea-polyacrylamide gel electrophoresis. That of the minor fraction (TP II) was less. The major band of both fractions had a molecular mass of approximately 20,000 daltons. Both proteins catalyzed the transfer of ganglioside GM1 as well as asialo-GM1, but transfer protein I was more effective with di- and trisialogangliosides. Transfer protein II appeared to be somewhat more specific for neutral glycolipids in that GA1 was transferred more rapidly than any of the gangliosides; however, lactosylceramide transfer was relatively slow. Neither protein catalyzed transfer of phosphatidylcholine. PMID:3689771

  6. Extension of the GLYCAM06 Biomolecular Force Field to Lipids, Lipid Bilayers and Glycolipids.

    Science.gov (United States)

    Tessier, Matthew B; Demarco, Mari L; Yongye, Austin B; Woods, Robert J

    2008-01-01

    GLYCAM06 is a generalisable biomolecular force field that is extendible to diverse molecular classes in the spirit of a small-molecule force field. Here we report parameters for lipids, lipid bilayers and glycolipids for use with GLYCAM06. Only three lipid-specific atom types have been introduced, in keeping with the general philosophy of transferable parameter development. Bond stretching, angle bending, and torsional force constants were derived by fitting to quantum mechanical data for a collection of minimal molecular fragments and related small molecules. Partial atomic charges were computed by fitting to ensemble-averaged quantum-computed molecular electrostatic potentials.In addition to reproducing quantum mechanical internal rotational energies and experimental valence geometries for an array of small molecules, condensed-phase simulations employing the new parameters are shown to reproduce the bulk physical properties of a DMPC lipid bilayer. The new parameters allow for molecular dynamics simulations of complex systems containing lipids, lipid bilayers, glycolipids, and carbohydrates, using an internally consistent force field. By combining the AMBER parameters for proteins with the GLYCAM06 parameters, it is also possible to simulate protein-lipid complexes and proteins in biologically relevant membrane-like environments. PMID:22247593

  7. Estrogen influences dolichyl phosphate distribution among glycolipid pools in mouse uteri

    International Nuclear Information System (INIS)

    To determine the role that dolichyl phosphate availability plays in this induction, the authors studied the effects of estrogen priming on the content of dolichyl phosphate and the distribution of dolichyl phosphate among various glycolipids in uteri. Dolichol-linked saccharides were metabolically labeled to equilibrium with either [3H]glucosamine or [3H]mannose and extracted from primary explants of uterine tissue. The amount of dolichol-linked saccharide was calculated from the specific radioactivity determined for the corresponding sugar nucleotides extracted from the tissues. The major dolichol-linked saccharides identified were mannosylphosphoryldolichol (MPD), oligosaccharylpyrophosphorydolichol (OSL), and N,N'-diacetylchitobiosylpyrophosphoryldolichol (CBL). Estrogen increased the levels of MPD and OSL 4-fold; however, CBL levels did not change. After 3 days of treatment, the levels of these glycolipids were very similar to those in uteri from pregnant mice. The specific activity of GPD synthase was similar under all conditions studied. These studies provide the first determination of the levels of dolichol-linked saccharides in tissues and how these levels change during hormonal induction of glycoprotein assembly. Coupled with earlier studies, the present work demonstrates that among a number of key points of N-linked oligosaccharide assembly and transfer only synthesis of MPD increases coordinately with the increase observed in lipid- and protein-linked oligosaccharide assembly that occurs in vivo in response to estrogen. They suggest that control of MPD levels is an important regulatory aspect of N-linked glycoprotein assembly in this system

  8. Major surface antigen, P30, of Toxoplasma gondii is anchored by a glycolipid

    International Nuclear Information System (INIS)

    P30, the major surface antigen of the parasitic protozoan Toxoplasma gondii, can be specifically labeled with [3H]palmitic acid and with myo-[2-3H]inositol. The fatty acid label can be released by treatment of P30 with phosphatidylinositol-specific phospholipase C (PI-PLC). Such treatment exposes an immunological cross-reacting determinant first described on Trypanosoma brucei variant surface glycoprotein. PI-PLC cleavage of intact parasites metabolically labeled with [35S]methionine results in the release of intact P30 polypeptide in a form which migrates faster in polyacrylamide gel electrophoresis. These results argue that P30 is anchored by a glycolipid. Results from thin layer chromatography analysis of purified [3H] palmitate-labeled P30 treated with PI-PLC, together with susceptibility to mild alkali hydrolysis and to cleavage with phospholipase A2, suggest that the glycolipid anchor of T. gondii P30 includes a 1,2-diacylglycerol moiety

  9. The neurite-initiating effect of microbial extracellular glycolipids in PC12 cells.

    Science.gov (United States)

    Isoda, H; Shinmoto, H; Matsumura, M; Nakahara, T

    1999-09-01

    The effects of several kinds of microbial extracellular glycolipids on neurite initiation in PC12 cells were examined. Addition of mannosylerythritol lipid-A (MEL-A), MEL-B, and sophorose lipid (SL) to PC12 cells caused significant neurite outgrowth. Other glycolipids, such as polyol lipid (PL), rhamnose lipid (RL), succinoyl trehalose lipid-A (STL-A) and STL-B caused no neurite-initiation. MEL-A increased acetylcholine esterase (AChE) activity to an extent similar to nerve growth factor (NGF). However, MEL-A induced one or two long neurites from the cell body, while NGF induced many neurites. In addition, MEL-A-induced differentiation was transient, and after 48 h, percentage of cells with neurites started to decrease in contrast to neurons induced by NGF, which occurred in a time-dependent manner. MEL-A could induce neurite outgrowth after treatment of PC12 cells with an anti-NGF receptor antibody that obstructed NGF action. These results indicate that MEL-A and NGF induce differentiation of PC12 cells through different mechanisms. PMID:19003137

  10. Aqueous-phase behavior of natural glycolipid biosurfactant mannosylerythritol lipid A: sponge, cubic, and lamellar phases.

    Science.gov (United States)

    Imura, Tomohiro; Hikosaka, Yusuke; Worakitkanchanakul, Wannasiri; Sakai, Hideki; Abe, Masahiko; Konishi, Masaaki; Minamikawa, Hiroyuki; Kitamoto, Dai

    2007-02-13

    The aqueous-phase behavior of mannosylerythritol lipid A (MEL-A), which is a glycolipid biosurfactant produced from vegetable oils by yeast strains of the genus Pseudozyma, was investigated using polarized optical microscopy, small-angle X-ray scattering (SAXS), and differential scanning calorimetry (DSC). MEL-A was found to self-assemble into a variety of distinctive lyotropic liquid crystals including sponge (L3), bicontinuous cubic (V2), and lamella (Lalpha) phases. On the basis of SAXS measurements, we determined the structure of the liquid crystals. The estimated lattice constant for Lalpha was 3.58 nm. DSC measurement revealed that the phase transition enthalpies from the liquid crystal to the fluid isotropic phase were in the range of 0.22-0.44 kJ/mol. Although the present MEL-A phase diagram closely resembled that obtained from relatively hydrophobic poly(oxyethylene) or fluorinated surfactants, the MEL-A L3 region was spread considerably over a wide temperature range (20-65 degrees C) compared to L3 of those surfactants: this is probably due to the unique structure which is molecularly engineered by microorganisms. In this paper, we clarify the aqueous phase diagram of the natural glycolipid biosurfactant MEL-A, and we suggest that the obtained lyotropic crystals are potentially useful as novel nanostructured biomaterials. PMID:17279642

  11. The moisturizing effects of glycolipid biosurfactants, mannosylerythritol lipids, on human skin.

    Science.gov (United States)

    Yamamoto, Shuhei; Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Yanagidani, Shusaku; Sogabe, Atsushi; Kitamoto, Dai; Kitagawa, Masaru

    2012-01-01

    Glycolipid biosurfactants, such as mannosylerythritol lipids (MELs), are produced by different yeasts belonging to the genus Pseudozyma and have been attracting much attention as new cosmetic ingredients owing to their unique liquid-crystal-forming and moisturizing properties. In this study, the effects of different MEL derivatives on the skin were evaluated in detail using a three-dimensional cultured human skin model and an in vivo human study. The skin cells were cultured and treated with sodium dodecyl sulfate (SDS), and the effects of different lipids on the SDS-damaged cells were evaluated on the basis of cell viability. Most MEL derivatives efficiently recovered the viability of the cells and showed high recovery rates (over 80%) comparable with that of natural ceramide. It is interesting that the recovery rate with MEL-A prepared from olive oil was significantly higher than that of MEL-A prepared from soybean oil. The water retention properties of MEL-B were further investigated on human forearm skin in a preliminary study. Compared with the control, the aqueous solution of MEL-B (5 wt%) was estimated to considerably increase the stratum corneum water content in the skin. Moreover, perspiration on the skin surface was clearly suppressed by treatment with the MEL-B solution. These results suggest that MELs are likely to exhibit a high moisturizing action, by assisting the barrier function of the skin. Accordingly, the yeast glycolipids have a strong potential as a new ingredient for skin care products. PMID:22790172

  12. Enzymatic synthesis of a novel glycolipid biosurfactant, mannosylerythritol lipid-D and its aqueous phase behavior.

    Science.gov (United States)

    Fukuoka, Tokuma; Yanagihara, Takashi; Imura, Tomohiro; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2011-02-01

    Mannosylerythritol lipids (MELs) produced by yeasts are one of the most promising glycolipid biosurfactants. In this study, we succeeded in the preparation of a novel MEL homolog having no acetyl groups, namely MEL-D. MEL-D was synthesized by lipase-catalyzed hydrolysis of acetyl groups from a known MEL, and identified as 4-O-[2',3'-di-O-alka(e)noyl-β-d-mannopyranosyl]-(2R,3S)-erythritol. The obtained MEL-D showed a higher critical aggregation concentration (CAC=1.2 × 10(-5)M) and hydrophilicity compared to known MELs, retaining an excellent surface tension lowering activity (the surface tension at the CAC was 24.5mN/m). In addition, we estimated the binary phase diagram of the MEL-D-water system based on a combination of visual inspection, polarized optical microscopy, and SAXS measurement. From these results, MEL-D was found to self-assemble into a lamellar (L(α)) structure over all ranges of concentration. Meanwhile, the one-phase L(α) region of MEL-D was extended wider than those of known MELs. MEL-D might keep more water between the polar layers in accordance with the extension of the interlayer spacing (d). These results suggest that the newly obtained MEL-D would facilitate the application of MELs in various fields as a lamellar-forming glycolipid with higher hydrate ability. PMID:21163471

  13. Mycobacteria glycolipids as potential pathogenicity effectors: alteration of model and natural membranes.

    Science.gov (United States)

    Sut, A; Sirugue, S; Sixou, S; Lakhdar-Ghazal, F; Tocanne, J F; Lanéelle, G

    1990-09-11

    Four mycobacterial wall glycolipids were tested for their effects on phospholipidic liposome organization and passive permeability and on oxidative phosphorylation of isolated mitochondria. From fluorescence polarization of diphenylhexatriene performed on liposomes it was concluded that the two trehalose derivatives (dimycoloyltrehalose and polyphthienoyltrehalose) rigidified the fluid state of liposomes, the triglycosyl phenolphthiocerol slightly fluidized the gel state, while the peptidoglycolipid ("apolar" mycoside C) just shifted the phase transition temperature upward. Dimycoloyltrehalose was without effect on liposome passive permeability, as estimated from dicarboxyfluorescein leak rates, and polyphthienoyltrehalose and triglycosyl phenolphthiocerol slightly decreased leaks, while mycoside C dramatically increased leaks. Activity of these lipids on mitochondrial oxidative phosphorylation was examined. The two trehalose derivatives have been tested previously: both had the same type of inhibitory activity, dimycoloyltrehalose being the most active. Triglycosyl phenolphthiocerol was inactive. Mycoside C was very active, with effects resembling those of classical uncouplers: this suggested that its activity on mitochondria was related to its effect on permeability. All these membrane alterations were called nonspecific because it is likely that they result from nonspecific lipid-lipid interactions, and not from recognition between specific molecular structures. Such nonspecific interactions could be at the origin of some of the effects of mycobacteria glycolipids on cells of the immune system observed in the last few years. PMID:2123718

  14. Cholesterol confusion and statin controversy

    Institute of Scientific and Technical Information of China (English)

    Robert; Du; Broff; Michel; de; Lorgeril

    2015-01-01

    The role of blood cholesterol levels in coronary heart disease(CHD) and the true effect of cholesterollowering statin drugs are debatable. In particular,whether statins actually decrease cardiac mortality and increase life expectancy is controversial. Concurrently,the Mediterranean diet model has been shown to prolong life and reduce the risk of diabetes,cancer,and CHD. We herein review current data related to both statins and the Mediterranean diet. We conclude that the expectation that CHD could be prevented or eliminated by simply reducing cholesterol appears unfounded. On the contrary,we should acknowledge the inconsistencies of the cholesterol theory and recognize the proven benefits of a healthy lifestyle incorporating a Mediterranean diet to prevent CHD.

  15. Effect of cholesterol oxidation products on cholesterol metabolism in the laying hen.

    Science.gov (United States)

    Naber, E C; Allred, J B; Winget, C J; Stock, A E

    1985-04-01

    Two experiments were conducted to determine the effect of purified cholesterol and oxidized cholesterol in the diet of the laying hen on egg production characteristics, in vitro - in ovo utilization of acetate for cholesterol biosynthesis, and the activity of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme in biosynthesis of cholesterol. Previous work has demonstrated inhibition of cholesterol synthesis by cholesterol oxides in tissue culture cells but not in hepatic tissues of animals through dietary administration. Feeding .5% of either purified or oxidized cholesterol had no effect on egg production, egg weight, body weight, or diet consumption. In both experiments egg yolk cholesterol was significantly increased by both cholesterol sources, but eggs from hens fed oxidized cholesterol had lower cholesterol contents than those from hens fed purified cholesterol. Relative utilization of acetate for cholesterol biosynthesis was significantly reduced by feeding both cholesterol sources. Hepatic enzyme activity measured by production of mevalonic acid was significantly inhibited by feeding purified cholesterol. A further significant reduction in enzyme activity was observed when oxidized cholesterol was fed, indicating that dietary cholesterol oxides are much more potent than purified cholesterol in limiting the activity of the enzyme. PMID:4001052

  16. Polarizable multipolar electrostatics for cholesterol

    Science.gov (United States)

    Fletcher, Timothy L.; Popelier, Paul L. A.

    2016-08-01

    FFLUX is a novel force field under development for biomolecular modelling, and is based on topological atoms and the machine learning method kriging. Successful kriging models have been obtained for realistic electrostatics of amino acids, small peptides, and some carbohydrates but here, for the first time, we construct kriging models for a sizeable ligand of great importance, which is cholesterol. Cholesterol's mean total (internal) electrostatic energy prediction error amounts to 3.9 kJ mol-1, which pleasingly falls below the threshold of 1 kcal mol-1 often cited for accurate biomolecular modelling. We present a detailed analysis of the error distributions.

  17. Constrained Jastrow calculations

    International Nuclear Information System (INIS)

    An alternative to Pandharipande's lowest order constrained variational prescription for dense Fermi fluids is presented which is justified on both physical and strict variational grounds. Excellent results are obtained when applied to the 'homework problem' of Bethe, in sharp contrast to those obtained from the Pandharipande prescription. (Auth.)

  18. Constrained Canonical Correlation.

    Science.gov (United States)

    DeSarbo, Wayne S.; And Others

    1982-01-01

    A variety of problems associated with the interpretation of traditional canonical correlation are discussed. A response surface approach is developed which allows for investigation of changes in the coefficients while maintaining an optimum canonical correlation value. Also, a discrete or constrained canonical correlation method is presented. (JKS)

  19. Constrained superfields in Supergravity

    CERN Document Server

    Dall'Agata, Gianguido

    2015-01-01

    We analyze constrained superfields in supergravity. We investigate the consistency and solve all known constraints, presenting a new class that may have interesting applications in the construction of inflationary models. We provide the superspace Lagrangians for minimal supergravity models based on them and write the corresponding theories in component form using a simplifying gauge for the goldstino couplings.

  20. [Attitude of blood donors towards cholesterol measurement].

    Science.gov (United States)

    Flesland, O; Botten, G; Solheim, B G; Orjasaeter, H

    1992-05-20

    In analyses of cost-effectiveness it is customary to count knowledge of having a high serum cholesterol level as a negative factor. There is little support for this practice in the literature. We have studied the attitude of 305 Norwegian blood donors towards cholesterol testing. 63% stated that they were interested in their serum cholesterol level, and 40% said they knew their own serum cholesterol level. The attitude towards cholesterol testing was clearly positive, both among men and among women, regardless of age. Only one donor stated that she did not want to have her serum cholesterol tested in conjunction with blood donation. PMID:1509430

  1. In Situ Conversion of Melanoma Lesions into Autologous Vaccine by Intratumoral Injections of α-gal Glycolipids

    International Nuclear Information System (INIS)

    Autologous melanoma associated antigens (MAA) on murine melanoma cells can elicit a protective anti-tumor immune response following a variety of vaccine strategies. Most require effective uptake by antigen presenting cells (APC). APC transport and process internalized MAA for activation of anti-tumor T cells. One potential problem with clinical melanoma vaccines against autologous tumors may be that often tumor cells do not express surface markers that label them for uptake by APC. Effective uptake of melanoma cells by APC might be achieved by exploiting the natural anti-Gal antibody which constitutes ~1% of immunoglobulins in humans. This approach has been developed in a syngeneic mouse model using mice capable of producing anti-Gal. Anti-Gal binds specifically to α-gal epitopes (Galα1-3Galβ1-4GlcNAc-R). Injection of glycolipids carrying α-gal epitopes (α-gal glycolipids) into melanoma lesions results in glycolipid insertion into melanoma cell membranes, expression of α-gal epitopes on the tumor cells and binding of anti-Gal to these epitopes. Interaction between the Fc portions of bound anti-Gal and Fcγ receptors on APC induces effective uptake of tumor cells by APC. The resulting anti-MAA immune response can be potent enough to destroy distant micrometastases. A clinical trial is now open testing effects of intratumoral α-gal glycolipid injections in melanoma patients

  2. Strain variations in the murine cellular immune response to the phenolic glycolipid I antigen of Mycobacterium leprae.

    Science.gov (United States)

    Koster, F T; Teuscher, C; Matzner, P; Umland, E; Yanagihara, D; Brennan, P J; Tung, K S

    1986-01-01

    The cellular immune response to the Mycobacterium leprae-specific phenolic glycolipid I was examined in inbred mice immunized with M. leprae by in vivo delayed cutaneous hypersensitivity and in vitro lymphocyte proliferation. Whereas all mouse strains responded to M.leprae-induced delayed-type hypersensitivity and lymphocyte proliferation, only BALB.K was responsive in both assays to the glycolipid. Responsiveness was determined in part by non-H-2 genes, while the influence of H-2 genes was not apparent. Among congenic BALB/c mice differing only at Igh-C allotype loci, variations in responsiveness were found in both delayed-type hypersensitivity and lymphocytes proliferation assays, indicating a possible role for Igh-C loci-linked genes. Unresponsiveness in the lymphocyte proliferation assay to the glycolipid was inherited as a dominant trait in one set of responder X nonresponder F1 progeny. We conclude that after immunization with M. leprae organisms, the cell-mediated responses to the glycolipid, endowed with a single carbohydrate epitope, are under polygenic control, predominantly non-H-2-linked genes. PMID:3510979

  3. Microbial conversion of glycerol into glycolipid biosurfactants, mannosylerythritol lipids, by a basidiomycete yeast, Pseudozyma antarctica JCM 10317(T).

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2007-07-01

    Microbial conversion of glycerol into functional bio-based materials was investigated, aiming to facilitate the utilization of waste glycerol. A basidiomycete yeast, Pseudozyma antarctica JCM 10317, efficiently produced mannosylerythritol lipids (MELs) as glycolipid biosurfactants from glycerol. The amount of MEL yield reached 16.3 g l(-1) by intermittent feeding of glycerol. PMID:17697987

  4. Draft Genome Sequence of the Yeast Pseudozyma antarctica Type Strain JCM10317, a Producer of the Glycolipid Biosurfactants, Mannosylerythritol Lipids.

    Science.gov (United States)

    Saika, Azusa; Koike, Hideaki; Hori, Tomoyuki; Fukuoka, Tokuma; Sato, Shun; Habe, Hiroshi; Kitamoto, Dai; Morita, Tomotake

    2014-01-01

    The basidiomycetous yeast Pseudozyma antarctica is known as a producer of industrial enzymes and the extracellular glycolipids, mannosylerythritol lipids. Here, we report the draft genome sequence of the type strain JCM10317. The draft genome assembly has a size of 18.1 Mb and a G+C content of 60.9%, and it consists of 197 scaffolds. PMID:25291760

  5. The ABC of cholesterol transport

    NARCIS (Netherlands)

    Plösch, Torsten

    2004-01-01

    Cholesterol fulfills an indispensable role in mammalian physiology. It is an important constituent of all cell membranes. Furthermore, it is the precursor of steroid hormones, which regulate a variety of physiological functions, and of bile salts, which are necessary for the generation of bile flow

  6. Membrane Cholesterol Modulates Superwarfarin Toxicity.

    Science.gov (United States)

    Marangoni, M Natalia; Martynowycz, Michael W; Kuzmenko, Ivan; Braun, David; Polak, Paul E; Weinberg, Guy; Rubinstein, Israel; Gidalevitz, David; Feinstein, Douglas L

    2016-04-26

    Superwarfarins are modified analogs of warfarin with additional lipophilic aromatic rings, up to 100-fold greater potency, and longer biological half-lives. We hypothesized that increased hydrophobicity allowed interactions with amphiphilic membranes and modulation of biological responses. We find that superwarfarins brodifacoum and difenacoum increase lactate production and cell death in neuroblastoma cells. In contrast, neither causes changes in glioma cells that have higher cholesterol content. After choleterol depletion, lactate production was increased and cell viability was reduced. Drug-membrane interactions were examined by surface X-ray scattering using Langmuir monolayers of dipalmitoylphosphatidylcholine and/or cholesterol. Specular X-ray reflectivity data revealed that superwarfarins, but not warfarin, intercalate between dipalmitoylphosphatidylcholine molecules, whereas grazing incidence X-ray diffraction demonstrated changes in lateral crystalline order of the film. Neither agent showed significant interactions with monolayers containing >20% cholesterol. These findings demonstrate an affinity of superwarfarins to biomembranes and suggest that cellular responses to these agents are regulated by cholesterol content. PMID:27119638

  7. Membrane Cholesterol Modulates Superwarfarin Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Marangoni, M. Natalia; Martynowycz, Michael W.; Kuzmenko, Ivan; Braun, David; Polak, Paul E.; Weinberg, Guy; Rubinstein, Israel; Gidalevitz, David; Feinstein, Douglas L.

    2016-04-26

    Superwarfarins are modified analogs of warfarin with additional lipophilic aromatic rings, up to 100-fold greater potency, and longer biological half-lives. We hypothesized that increased hydrophobicity allowed interactions with amphiphilic membranes and modulation of biological responses. We find that superwarfarins brodifacoum and difenacoum increase lactate production and cell death in neuroblastoma cells. In contrast, neither causes changes in glioma cells that have higher cholesterol content. After choleterol depletion, lactate production was increased and cell viability was reduced. Drug-membrane interactions were examined by surface X-ray scattering using Langmuir monolayers of dipalmitoylphosphatidylcholine and/or cholesterol. Specular X-ray reflectivity data revealed that superwarfarins, but not warfarin, intercalate between dipalmitoylphosphatidylcholine molecules, whereas grazing incidence X-ray diffraction demonstrated changes in lateral crystalline order of the film. Neither agent showed significant interactions with monolayers containing >20% cholesterol. These findings demonstrate an affinity of superwarfarins to biomembranes and suggest that cellular responses to these agents are regulated by cholesterol content.

  8. Active membrane cholesterol as a physiological effector.

    Science.gov (United States)

    Lange, Yvonne; Steck, Theodore L

    2016-09-01

    Sterols associate preferentially with plasma membrane sphingolipids and saturated phospholipids to form stoichiometric complexes. Cholesterol in molar excess of the capacity of these polar bilayer lipids has a high accessibility and fugacity; we call this fraction active cholesterol. This review first considers how active cholesterol serves as an upstream regulator of cellular sterol homeostasis. The mechanism appears to utilize the redistribution of active cholesterol down its diffusional gradient to the endoplasmic reticulum and mitochondria, where it binds multiple effectors and directs their feedback activity. We have also reviewed a broad literature in search of a role for active cholesterol (as opposed to bulk cholesterol or lipid domains such as rafts) in the activity of diverse membrane proteins. Several systems provide such evidence, implicating, in particular, caveolin-1, various kinds of ABC-type cholesterol transporters, solute transporters, receptors and ion channels. We suggest that this larger role for active cholesterol warrants close attention and can be tested easily. PMID:26874289

  9. Do You Know Your Cholesterol Levels?

    Science.gov (United States)

    ... The Health Information Center Do You Know Your Cholesterol Levels? Print-friendly Version (PDF, 6.1 MB) ... Eat Smart Did you know that high blood cholesterol is a serious problem among Latinos? About one ...

  10. Sharp spatially constrained inversion

    DEFF Research Database (Denmark)

    Vignoli, Giulio G.; Fiandaca, Gianluca G.; Christiansen, Anders Vest C A.V.C.; Kirkegaard, Casper C.; Auken, Esben

    We present sharp reconstruction of multi-layer models using a spatially constrained inversion with minimum gradient support regularization. In particular, its application to airborne electromagnetic data is discussed. Airborne surveys produce extremely large datasets, traditionally inverted by...... using smoothly varying 1D models. Smoothness is a result of the regularization constraints applied to address the inversion ill-posedness. The standard Occam-type regularized multi-layer inversion produces results where boundaries between layers are smeared. The sharp regularization overcomes this by......, the results are compatible with the data and, at the same time, favor sharp transitions. The focusing strategy can also be used to constrain the 1D solutions laterally, guaranteeing that lateral sharp transitions are retrieved without losing resolution. By means of real and synthetic datasets, sharp...

  11. Cerebral cholesterol granuloma in homozygous familial hypercholesterolemia

    OpenAIRE

    Francis, Gordon A; Johnson, Royce L.; Findlay, J. Max; Wang, Jian; Hegele, Robert A.

    2005-01-01

    Familial hypercholesterolemia (FH) is characterized by the accumulation of excess cholesterol in tissues including the artery wall and tendons. We describe a patient with homozygous FH who presented with asymptomatic cholesterol granuloma of the brain. The patient's plasma low-density lipoprotein cholesterol level was remarkably responsive to combination hypolipidemic therapy with statin plus ezetimibe. This case illustrates another potential complication of whole-body cholesterol excess and ...

  12. Constrained noninformative priors

    International Nuclear Information System (INIS)

    The Jeffreys noninformative prior distribution for a single unknown parameter is the distribution corresponding to a uniform distribution in the transformed model where the unknown parameter is approximately a location parameter. To obtain a prior distribution with a specified mean but with diffusion reflecting great uncertainty, a natural generalization of the noninformative prior is the distribution corresponding to the constrained maximum entropy distribution in the transformed model. Examples are given

  13. Quercetin regulates hepatic cholesterol metabolism by promoting cholesterol-to-bile acid conversion and cholesterol efflux in rats.

    Science.gov (United States)

    Zhang, Min; Xie, Zongkai; Gao, Weina; Pu, Lingling; Wei, Jingyu; Guo, Changjiang

    2016-03-01

    Quercetin, a common member of the flavonoid family, is widely present in plant kingdom. Despite that quercetin is implicated in regulating cholesterol metabolism, the molecular mechanism is poorly understood. We hypothesized that quercetin regulates cholesterol homeostasis through regulating the key enzymes involved in hepatic cholesterol metabolism. To test this hypothesis, we compared the profile of key enzymes and transcription factors involved in the hepatic cholesterol metabolism in rats with or without quercetin supplementation. Twenty male Wistar rats were randomly divided into control and quercetin-supplemented groups. Serum total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total bile acids in feces and bile were measured. Hepatic enzymatic activities were determined by activity assay kit and high-performance liquid chromatography-based analyses. The messenger RNA (mRNA) and protein expressions were determined by reverse transcriptase polymerase chain reaction and Western blot analyses, respectively. The results showed that the activity of hepatic cholesterol 7α-hydroxylase, a critical enzyme in the conversion of cholesterol to bile acids, was significantly elevated by quercetin. The expression of cholesterol 7α-hydroxylase, as well as liver X receptor α, an important transcription factor, was also increased at both mRNA and protein levels by quercetin. However, quercetin exposure had no impact on the activity of hepatic HMG-CoA reductase, a rate-limiting enzyme in the biosynthesis of cholesterol. We also found that quercetin treatment significantly increased ATP binding cassette transporter G1 mRNA and protein expression in the liver, suggesting that quercetin may increase hepatic cholesterol efflux. Collectively, the results presented here indicate that quercetin regulates hepatic cholesterol metabolism mainly through the pathways that promote cholesterol-to-bile acid conversion and

  14. High Cholesterol: Medicines to Help You

    Science.gov (United States)

    ... risks of taking these medicines. Talk to your doctor or pharmacist about all of the risks of taking your ... 20 should have their cholesterol checked by a doctor. Most people do not show ... Good vs. Bad Cholesterol Not all cholesterol in your blood ...

  15. Isolation of Cholesterol from an Egg Yolk

    Science.gov (United States)

    Taber, Douglass F.; Li, Rui; Anson, Cory M.

    2011-01-01

    A simple procedure for the isolation of the cholesterol, by hydrolysis and extraction followed by column chromatography, is described. The cholesterol can be further purified by complexation with oxalic acid. It can also be oxidized and conjugated to cholestenone. The source of the cholesterol is one egg yolk, which contains about 200 mg of…

  16. Intestinal cholesterol secretion : future clinical implications

    NARCIS (Netherlands)

    Jakulj, L.; Besseling, J.; Stroes, E. S. G.; Groen, A. K.

    2013-01-01

    Together with the liver, the intestine serves as a homeostatic organ in cholesterol metabolism. Recent evidence has substantiated the pivotal role of the intestine in reverse cholesterol transport (RCT). RCT is a fundamental antiatherogenic pathway, mediating the removal of cholesterol from tissues

  17. Remnant cholesterol and ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G

    2014-01-01

    PURPOSE OF REVIEW: To review recent advances in the field of remnant cholesterol as a contributor to the development of ischemic heart disease (IHD). RECENT FINDINGS: Epidemiologic, mechanistic, and genetic studies all support a role for elevated remnant cholesterol (=cholesterol in triglyceride...

  18. Expression of α2,6-sialic acid-containing and Lewis-active glycolipids in several types of human ovarian carcinomas

    OpenAIRE

    Tanaka, Kyoko; Mikami, Mikio; Aoki, Daisuke; Kiguchi, Kazushige; Ishiwata, Isamu; IWAMORI, MASAO

    2010-01-01

    To identify glycolipid antigens associated with histologically defined types of ovarian carcinomas, we determined the amounts of α2,6-sialyl and Lewis-active glycolipids, the specific activities of the α2,3- and α2,6-sialyltransferases, and the gene expression of sugar transferases in mucinous and serous cystadenocarcinoma, clear cell adenocarcinoma and endometrioid carcinoma tissues and cell lines derived from them. α2,6-sialyl glycolipid IV6NeuAcα-nLc4Cer detected with a newly developed mon...

  19. Study on Cholesterol Renewal of Fatty Livers by Means of Tritiated Cholesterol

    International Nuclear Information System (INIS)

    It is known that ingestion by rats of a diet rich in cholesterol (2%) results in the formation of cholesterol-fatty liver. In the experiment, animals so fed for periods of one to three months were made to ingest the same diet in which the cholesterol had been replaced by tritiated cholesterol of known specific radioactivity. The rats were sacrificed after various ingestion periods up to a maximum of 51 d. Examination of the specific radioactivities of liver and serum cholesterol, free and esterified, gave the same values. Hence, the cholesterol of cholesterol-fatty livers is entirely renewed and does not represent an inert mass in the liver. (author)

  20. Urokinase-catalysed cleavage of the urokinase receptor requires an intact glycolipid anchor

    DEFF Research Database (Denmark)

    Høyer-Hansen, G; Pessara, U; Holm, A;

    2001-01-01

    reaction, even though the actual cleavage occurs between the first and second domains. Purified full-length GPI-anchored uPAR (GPI-uPAR) proved much more susceptible to uPA-mediated cleavage than recombinant truncated soluble uPAR (suPAR), which lacks the glycolipid anchor. This was not a general...... difference in proteolytic susceptibility since GPI-uPAR and suPAR were cleaved with equal efficiency by plasmin. Since the amino acid sequences of GPI-uPAR and suPAR are identical except for the C-terminal truncation, the different cleavage patterns suggest that the two uPAR variants differ in the......PAR, purified from plasma, was found to have a similar resistance to uPA cleavage as phospholipase C-treated GPI-uPAR and recombinant suPAR....

  1. Reverse vesicle formation from the yeast glycolipid biosurfactant mannosylerythritol lipid-D.

    Science.gov (United States)

    Fukuoka, Tokuma; Yanagihara, Takashi; Ito, Seya; Imura, Tomohiro; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2012-01-01

    Mannosylerythritol lipids (MELs) are secreted by yeasts and are promising glycolipid biosurfactants. In our study on the non-aqueous phase behaviors of MEL homologues, we found that MEL-D (4-O-[2',3'-di-O-alka(e)noyl-β-D-mannopyranosyl]-(2R,3S)-erythritol) forms aggregates in decane. The microscopic observation and the X-ray scattering measurement of these aggregates revealed that they are reverse vesicles that consist of bilayers whose hydrophilic domains are located in the interior of the bilayers. In addition, MEL-D formed reverse vesicles without co-surfactants and co-solvents in various oily solutions, such as n-alkanes, cyclohexane, squalane, squalene, and silicone oils at a concentration below 10 mM. This is the first report on the reverse vesicle formation from biosurfactants. PMID:22531056

  2. Non-cholesterol sterols and cholesterol metabolism in sitosterolemia.

    Science.gov (United States)

    Othman, Rgia A; Myrie, Semone B; Jones, Peter J H

    2013-12-01

    Sitosterolemia (STSL) is a rare autosomal recessive disease, manifested by extremely elevated plant sterols (PS) in plasma and tissue, leading to xanthoma and premature atherosclerotic disease. Therapeutic approaches include limiting PS intake, interrupting enterohepatic circulation of bile acid using bile acid binding resins such as cholestyramine, and/or ileal bypass, and inhibiting intestinal sterol absorption by ezetimibe (EZE). The objective of this review is to evaluate sterol metabolism in STSL and the impact of the currently available treatments on sterol trafficking in this disease. The role of PS in initiation of xanthomas and premature atherosclerosis is also discussed. Blocking sterols absorption with EZE has revolutionized STSL patient treatment as it reduces circulating levels of non-cholesterol sterols in STSL. However, none of the available treatments including EZE have normalized plasma PS concentrations. Future studies are needed to: (i) explore where cholesterol and non-cholesterol sterols accumulate, (ii) assess to what extent these sterols in tissues can be mobilized after blocking their absorption, and (iii) define the factors governing sterol flux. PMID:24267242

  3. Cholesterol Depletion from a Ceramide/Cholesterol Mixed Monolayer: A Brewster Angle Microscope Study

    KAUST Repository

    Mandal, Pritam

    2016-06-01

    Cholesterol is crucial to the mechanical properties of cell membranes that are important to cells’ behavior. Its depletion from the cell membranes could be dramatic. Among cyclodextrins (CDs), methyl beta cyclodextrin (MβCD) is the most efficient to deplete cholesterol (Chol) from biomembranes. Here, we focus on the depletion of cholesterol from a C16 ceramide/cholesterol (C16-Cer/Chol) mixed monolayer using MβCD. While the removal of cholesterol by MβCD depends on the cholesterol concentration in most mixed lipid monolayers, it does not depend very much on the concentration of cholesterol in C16-Cer/Chol monolayers. The surface pressure decay during depletion were described by a stretched exponential that suggested that the cholesterol molecules are unable to diffuse laterally and behave like static traps for the MβCD molecules. Cholesterol depletion causes morphology changes of domains but these disrupted monolayers domains seem to reform even when cholesterol level was low.

  4. Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques

    International Nuclear Information System (INIS)

    Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6′-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-γ, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection

  5. Decay accelerating factor of complement is anchored to cells by a C-terminal glycolipid

    International Nuclear Information System (INIS)

    Membrane-associated decay accelerating factor (DAF) of human erythrocytes (E/sup hu/) was analyzed for a C-terminal glycolipid anchoring structure. Automated amino acid analysis of DAF following reductive radiomethylation revealed ethanolamine and glucosamine residues in proportions identical with those present in the E/sup hu/ acetylcholinesterase (AChE) anchor. Cleavage of radiomethylated 70-kilodalton (kDa) DAF with papain released the labeled ethanolamine and glucosamine and generated 61- and 55-kDa DAF products that retained all labeled Lys and labeled N-terminal Asp. Incubation of intact E/sup hu/ with phosphatidylinositol-specific phospholipase C (PI-PLC), which cleaves the anchors in trypanosome membrane form variant surface glycoproteins (mfVSGs) and murine thymocyte Thy-1 antigen, released 15% of the cell-associated DAF antigen. The released 67-kDa PI-PLC DAF derivative retained its ability to decay the classical C3 convertase C4b2a but was unable to membrane-incorporate and displayed physicochemical properties similar to urine DAF, a hydrophilic DAF form that can be isolated for urine. Nitrous acid deamination cleavage of E/sup hu/ DAF at glucosamine following labeling with the lipophilic photoreagent 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine ([125I]TID) released the [125I]TID label in a parallel fashion as from [125I]TID-labeled AChE. Biosynthetic labeling of HeLa cells with [3H] ethanolamine resulted in rapid 3H incorporation into both 48-kDa pro-DAF and 72-kDa mature epithelial cell DAF. The findings indicate that DAF and AChE are anchored in E/sup hu/ by the same or a similar glycolipid structure and that, like VSGs, this structure is incorporated into DAF early in DAF biosynthesis prior to processing of pro-DAF in the Golgi

  6. Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Daisuke; Miyamoto, Ayumi; Hattori, Yuki; Komori, Takaya [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Nakamura, Takashi [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Igarashi, Tatsuhiko, E-mail: tigarash@virus.kyoto-u.ac.jp [Laboratory of Primate Model, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Harashima, Hideyoshi, E-mail: harasima@pharm.hokudai.ac.jp [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Sugita, Masahiko, E-mail: msugita@virus.kyoto-u.ac.jp [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)

    2013-11-08

    Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6′-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-γ, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection.

  7. Aqueous-phase behavior and vesicle formation of natural glycolipid biosurfactant, mannosylerythritol lipid-B.

    Science.gov (United States)

    Worakitkanchanakul, Wannasiri; Imura, Tomohiro; Fukuoka, Tokuma; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Rujiravanit, Ratana; Chavadej, Sumaeth; Minamikawa, Hiroyuki; Kitamoto, Dai

    2008-08-01

    Mannosylerythritol lipids (MELs) are one of the most promising glycolipid biosurfactants produced by yeast strains of the genus Pseudozyma. In this study, the aqueous-phase behavior of a new monoacetyl MEL derivative, 1-O-beta-(2',3'-di-O-alka(e)noyl-6'-O-acetyl-d-mannopyranosyl)-d-erythritol (MEL-B), was investigated using polarized optical microscopy, small-angle X-ray scattering (SAXS), confocal laser scanning microscopy (CLSM), and differential scanning calorimetry (DSC). The present MEL-B was found to self-assemble into a lamellar (L(alpha)) phase over remarkably wide concentration and temperature ranges. According to SAXS measurement, the interlayer spacing (d) was estimated to be almost constant (about 4.7 nm) at the low MEL-B concentration (60 wt.%) region, the d-spacing gradually decreased to 3.1 nm with an increase in the MEL-B concentration. The thermal stability of the liquid crystalline phase was investigated by DSC measurement. The obtained L(alpha) phase was found to be stable up to 95 degrees C below a MEL-B concentration of 85 wt.%; then, the melting temperature of the liquid crystalline phase dramatically decreased with an increase in MEL-B concentration (above 85 wt.%). Furthermore, we found relatively large vesicles (1-5 microm) at the low MEL-B concentration using CLSM observation. The trapped volume of the obtained MEL-B vesicle was estimated to be about 0.42 microL/mumol by glucose dialysis method. These results suggest that the natural glycolipid biosurfactant, the newly found MEL-B, would be useful in various fields of applications as an L(alpha) phase- and/or vesicle-forming lipid. PMID:18456469

  8. How cholesterol homeostasis is regulated by plasma membrane cholesterol in excess of phospholipids

    OpenAIRE

    Lange, Yvonne; Ye, Jin; Steck, Theodore L.

    2004-01-01

    How do cells sense and control their cholesterol levels? Whereas most of the cell cholesterol is located in the plasma membrane, the effectors of its abundance are regulated by a small pool of cholesterol in the endoplasmic reticulum (ER). The size of the ER compartment responds rapidly and dramatically to small changes in plasma membrane cholesterol around the normal level. Consequently, increasing plasma membrane cholesterol in vivo from just below to just above the basal level evoked an ac...

  9. Endogenous cholesterol synthesis, fecal steroid excretion and serum lanosterol in subjects with high or low response of serum cholesterol to dietary cholesterol

    OpenAIRE

    A. C. Beynen; Katan, M B; Gent, van, H.

    1986-01-01

    In this study we addressed the question whether hypo- and hyper-responders to dietary cholesterol differ with regard to the flexibility of endogenous cholesterol synthesis after changes in cholesterol intake. Whole-body cholesterol synthesis was measured as faecal excretion of neutral steroids and bile acids minus cholesterol intake. In addition, we determined serum concentrations of lanosterol, a precursor of cholesterol and a possible indicator of cholesterol biosynthetic activity. The stud...

  10. Epididymis cholesterol homeostasis and sperm fertilizing ability

    Institute of Scientific and Technical Information of China (English)

    Fabrice Saez; Aurélia Ouvrier; Jo(e)l R Drevet

    2011-01-01

    Cholesterol, being the starting point of steroid hormone synthesis, is a long known modulator of both female and male reproductive physiology especially at the level of the gonads and the impact cholesterol has on gametogenesis. Less is known about the effects cholesterol homeostasis may have on postgonadic reproductive functions. Lately, several data have been reported showing how imbalanced cholesterol levels may particularly affect the post-testicular events of sperm maturation that lead to fully fertile male gametes. This review will focus on that aspect and essentially centers on how cholesterol is important for the physiology of the mammalian epididymis and spermatozoa.

  11. Peptide mediators of cholesterol efflux

    Science.gov (United States)

    Bielicki, John K.; Johansson, Jan

    2013-04-09

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  12. Trapping crystal nucleation of cholesterol monohydrate

    DEFF Research Database (Denmark)

    Solomonov, I.; Weygand, M.J.; Kjær, K.; Rapaport, H.; Leiserowitz, L.

    2005-01-01

    Crystalline nucleation of cholesterol at the air-water interface has been studied via grazing incidence x-ray diffraction using synchrotron radiation. The various stages of cholesterol molecular assembly from monolayer to three bilayers incorporating interleaving hydrogen-bonded water layers in a...... least initially, an intralayer cholesterol rearrangement in a single-crystal-to-single-crystal transition. The preferred nucleation of the monoclinic phase of cholesterol . H2O followed by transformation to the stable monohydrate phase may be associated with an energetically more stable cholesterol...... bilayer arrangement of the former and a more favorable hydrogen-bonding arrangement of the latter. The relevance of this nucleation process of cholesterol monohydrate to pathological crystallization of cholesterol from cell biomembranes is discussed....

  13. The Role of Cholesterol in Cancer.

    Science.gov (United States)

    Kuzu, Omer F; Noory, Mohammad A; Robertson, Gavin P

    2016-04-15

    The roles played by cholesterol in cancer development and the potential of therapeutically targeting cholesterol homeostasis is a controversial area in the cancer community. Several epidemiologic studies report an association between cancer and serum cholesterol levels or statin use, while others suggest that there is not one. Furthermore, the Cancer Genome Atlas (TCGA) project using next-generation sequencing has profiled the mutational status and expression levels of all the genes in diverse cancers, including those involved in cholesterol metabolism, providing correlative support for a role of the cholesterol pathway in cancer development. Finally, preclinical studies tend to more consistently support the role of cholesterol in cancer, with several demonstrating that cholesterol homeostasis genes can modulate development. Because of space limitations, this review provides selected examples of the epidemiologic, TCGA, and preclinical data, focusing on alterations in cholesterol homeostasis and its consequent effect on patient survival. In melanoma, this focused analysis demonstrated that enhanced expression of cholesterol synthesis genes was associated with decreased patient survival. Collectively, the studies in melanoma and other cancer types suggested a potential role of disrupted cholesterol homeostasis in cancer development but additional studies are needed to link population-based epidemiological data, the TCGA database results, and preclinical mechanistic evidence to concretely resolve this controversy. Cancer Res; 76(8); 2063-70. ©2016 AACR. PMID:27197250

  14. The phase behavior of hydrated cholesterol.

    Science.gov (United States)

    Loomis, C R; Shipley, G G; Small, D M

    1979-05-01

    The thermotropic phase behavior of cholesterol monohydrate in water was investigated by differential scanning calorimetry, polarizing light microscopy, and x-ray diffraction. In contrast to anhydrous cholesterol which undergoes a polymorphic crystalline transition at 39 degrees C and a crystalline to liquid transition at 151 degrees C, the closed system of cholesterol monohydrate and water exhibited three reversible endothermic transitions at 86, 123, and 157 degrees C. At 86 degrees C, cholesterol monohydrate loses its water of hydration, forming the high temperature polymorph of anhydrous cholesterol. At least 24 hours were required for re-hydration of cholesterol and the rate of hydration was dependent on the polymorphic crystalline form of anhydrous cholesterol. At 123 degrees C, anhydrous crystalline cholesterol in the presence of excess water undergoes a sharp transition to a birefringent liquid crystalline phase of smectic texture. The x-ray diffraction pattern obtained from this phase contained two sharp low-angle reflections at 37.4 and 18.7 A and a diffuse wide-angle reflection centered at 5.7 A, indicating a layered smectic type of liquid crystalline structure with each layer being two cholesterol molecules thick. The liquid crystalline phase is stable over the temperature range of 123 to 157 degrees C before melting to a liquid dispersed in water. The observation of a smectic liquid crystalline phase for hydrated cholesterol correlates with its high surface activity and helps to explain its ability to exist in high concentrations in biological membranes. PMID:458269

  15. Phenolic glycolipid-1 of Mycobacterium leprae binds complement component C3 in serum and mediates phagocytosis by human monocytes

    OpenAIRE

    1991-01-01

    Previous studies from this laboratory have demonstrated that Mycobacterium leprae, an obligate intracellular bacterial parasite, enters human mononuclear phagocytes via complement receptors on these host cells and bacterium-bound C3. The present study investigates the role of M. leprae surface molecules in C3 fixation and phagocytosis. By enzyme-linked immunosorbent assay, C3 binds selectively to phenolic glycolipid-1 (PGL-1), a major surface molecule of the leprosy bacillus. C3 fixation to P...

  16. Production of glycolipid biosurfactants, mannosylerythritol lipids, using sucrose by fungal and yeast strains, and their interfacial properties.

    Science.gov (United States)

    Morita, Tomotake; Ishibashi, Yuko; Fukuoka, Tokuma; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2009-10-01

    Glycolipid biosurfactants, mannosylerythritol lipids (MELs), were produced from glucose and sucrose without vegetable oils. Pseudozyma antarctica JCM 10317, Ustilago maydis NBRC 5346, U. scitaminea NBRC 32730, and P. siamensis CBS 9960 produced mainly MEL-A, MEL-A, MEL-B, and MEL-C respectively. The sucrose-derived MELs showed excellent interfacial properties: low critical micelle concentration as well as that of oil-derived MELs. PMID:19809166

  17. Specific tumor delivery of paclitaxel using glycolipid-like polymer micelles containing gold nanospheres.

    Science.gov (United States)

    You, Jian; Wang, Zuhua; Du, Yongzhong; Yuan, Hong; Zhang, Peizun; Zhou, Jialin; Liu, Fei; Li, Chun; Hu, Fuqiang

    2013-06-01

    It is difficult for most of the drug delivery systems to really display a temporal and spatial release of entrapped drug once the systems are iv administrated. We hypothesized that the photothermal effect, mediated by a near-infrared (NIR) laser and hollow gold nanospheres (HAuNS), can modulate paclitaxel (PTX) release from polymer micelles, and further result in the enhanced antitumor activity of the micelles. We loaded PTX and HAuNS, which display strong plasmon absorption in the NIR region, into glycolipid-like polymer micelles with an excellent cell internalization capability. The surface of the micelles was conjugated successfully with a peptide, which has the specific-binding with EphB4, a member of the Eph family of receptor tyrosine kinases overexpressed on cell membrane of numerous tumors, to increase the delivery of PTX into tumor cells. Rapid and repetitive drug release from our polymer (HP-TCS) micelles could be readily achieved upon NIR laser irradiation. Our data demonstrated the specific delivery of HP-TCS micelles into positive-EphB4 tumors using a duel-tumor model after iv administration during the whole experiment process (1-48 h). Interestingly, significantly higher uptake of the micelles by SKOV3 tumors (positive-EphB4) than A549 tumors (negtive-EphB4) was observed, with increased ratio on experiment time. However, the specific cell uptake was observed only during the short incubation time (1-4 h) in vitro. Our data also indicated the treatment of tumor cells with the micelles followed by NIR laser irradiation showed significantly greater toxicity activity than the treatment with the micelles alone, free PTX and the micelles (without PTX loading) plus NIR laser irradiation. The enhanced toxicity activity to tumor cells should be attributed to the enhanced drug cellular uptake mediated by the glycolipid-like micelles, chemical toxicity of the released drug from the micelles due to the trigger of NIR laser, and the photothermal ablation under NIR

  18. Identification of Pseudozyma graminicola CBS 10092 as a producer of glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Yamamoto, Shuhei; Kitagawa, Masaru; Sogabe, Atsushi; Kitamoto, Dai

    2008-01-01

    A basidiomycetous yeast, Pseudozyma graminicola CBS 10092, was found to accumulate a large amount of glycolipids in the cultured medium when grown on soybean oil as the sole carbon source. Based on thin layer chromatography, the extracellular glycolipids gave spots corresponding to those of mannosylerythritol lipids (MELs), which are highly functional and promising biosurfactants. From the structural characterization by 1H and 13C NMR, the main product was identified as 4-O-[(4'-mono-O-acetyl-2', 3'-di-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol, which is a highly hydrophilic derivative of MELs known as MEL-C. According to high-performance liquid chromatography analysis, the main product, MEL-C, comprised approximately 85% of all the MELs, and the total amount reached approximately 10 g/L for 7 days. The fatty acids of the present MEL-C consisted of mainly C6, C8 and C14 acids, considerably different from those of MEL-C produced by other Pseudozyma strains such as P. antarctica and P. shanxiensis. The observed critical micelle concentration (CMC) and the surface-tension at CMC of the MEL-C were 4.0 x 10(-6) M and 24.2 mN/m, respectively, while those of MEL-A, the most intensively studied MEL, were 2.7 x 10(-6) M and 28.4 mN/m, respectively. This implied that the MEL-C has higher hydrophilicity than conventional MELs hitherto reported. In addition, on a water-penetration scan, the MEL-C efficiently formed the lamella phase (Lalpha) at a wide range of concentrations, indicating its excellent self-assembling properties. From these results, the newly identified MELs produced by P. graminicola are likely to have great potential for use in oil-in-water type emulsifiers and/or washing detergents, and would thus facilitate a broad range of applications for the promising yeast biosurfactants. PMID:18198469

  19. Biliary cholesterol secretion: More than a simple ABC

    Institute of Scientific and Technical Information of China (English)

    Arne; Dikkers; Uwe; JF; Tietge

    2010-01-01

    Biliary cholesterol secretion is a process important for 2 major disease complexes, atherosclerotic cardiovascular disease and cholesterol gallstone disease. With respect to cardiovascular disease, biliary cholesterol secretion is regarded as the f inal step for the elimination of cholesterol originating from cholesterol-laden macrophage foam cells in the vessel wall in a pathway named reverse cholesterol transport. On the other hand, cholesterol hypersecretion into the bile is considered the main pathophys...

  20. Human sperm motility stimulating activity of a sulfono glycolipid isolated from Sri Lankan marine red alga Gelidiella acerosa

    Institute of Scientific and Technical Information of China (English)

    G. A.S. Premakumara; W.D. Ratnasooriya; L.M.V. Tillekeratne; A. S. Amarasekare; Atta-Ur-Rahman

    2001-01-01

    To evaluate the sperm motility stimulating activity of a sulfono glycolipid (S-ACT-l) isolated from Gelidiella acerosa, a Sri Lankan marine red algae. Methods: S-ACT-l, a white amorphous powder was separated from more polar fractions of the hexane soluble of 1:1 CH2Cl2/MeOH extract and subjected to 1H, 1 3C NMR and IR Spectroscopy after reverse phase HPLC for identification. Effects of S-ACT-1 on human sperm motility was assessed in vitro at 10,100 and 1000μg/Ml concentrations at 37℃ for 0, 5, 15, 30 and 60 min. Results: S-ACT-1 was identified as a glycolipid sulfate. The lower dose increased the sperm motility slightly, whilst the medium dose significantly increased the motility ( P < 0.05) from 5 min of incubation reaching a peak at 15 min and the stimulant effect was sustained throughout the experimental period. Furthermore, the medium dose rendered 80% of the immotile viable sperm motile.In contrast, the highest dose impaired the sperm motility. The sperm stimulating activity of S-ACT-1 was dose-depen dent and had a bell-shaped dose response curve for all the 5 incubation periods. Conclusion: S-ACT-1 of Gelidiella acerosa is a Sulfono glycolipid. S-ACT-1 has a potent sperm motility stimulating activity in vitro and has the potential to be developed into a sperm stimulant.

  1. Correlation of bacterial viability with uptake of (14C) acetate into phenolic glycolipid-1 of Mycobacterium leprae within Schwannoma cells

    International Nuclear Information System (INIS)

    The viability of Mycobacterium leprae, maintained within 33B Schwannoma cells, was estimated in terms of incorporation of (14C) acetate into its specific phenolic glycolipid-1. This measure of viability was correlated with two other assays, viz., fluorescein diacetate/ethidium bromide staining and mouse footpad growth. Observation of a 2-fold increase in the number of intracellular Mycobacterium leprae over an experimental period of 12 days also corroborated this contention. Furthermore, on addition of anti-leprosy drugs to these intracellular Mycobacterium leprae there was significant decrease in phenolic glycolipid-1 synthesis indicative of loss of viability of the organisms. This study also established the importance of the host cell for active bacillary metabolism, as Mycobacterium leprae maintained in cell-free conditions showed no incorporation into phenolic glycolipid-1. Moreover, compromising the host's protein synthesis capacity with cycloheximide, also led to reduction in bacillary metabolism. As this system measures the metabolic synthesis of a unique Mycobacterium leprae component, it would be useful for development and screening of compounds acting against specific bacillary targets. (author). 19 refs., 5 tabs

  2. Functions and potential applications of glycolipid biosurfactants--from energy-saving materials to gene delivery carriers.

    Science.gov (United States)

    Kitamoto, Dai; Isoda, Hiroko; Nakahara, Tadaatsu

    2002-01-01

    Biosurfactants (BS) produced by various microorganisms show unique properties (e.g., mild production conditions, lower toxicity, higher biodegradability and environmental compatibility) compared to their chemical counterparts. The numerous advantages of BS have prompted applications not only in the food, cosmetic, and pharmaceutical industries but in environmental protection and energy-saving technology as well. Glycolipid BS are the most promising, due to high productivity from renewable resources and versatile biochemical properties. Mannosylerythritol lipids (MEL), which are glycolipid BS produced by a yeast Candida antarctrica, exhibit not only excellent interfacial properties but also remarkable differentiation-inducing activities against human leukemia cells. MEL also show a potential anti-agglomeration effect on ice particles in ice slurry used for cold thermal storage. Recently, the cationic liposome bearing MEL has been demonstrated to increase dramatically the efficiency of gene transfection into mammalian cells. These features of BS should broaden its applications in new advanced technologies. The current status of research and development on glycolipid BS, especially their function and potential applications, is discussed. PMID:16233292

  3. CHOLESTEROL ASSIMILATION BY COMMERCIAL YOGHURT STARTER CULTURES

    OpenAIRE

    Małgorzata Ziarno; Ewa Sękul; Alvaro Aguado Lafraya

    2007-01-01

    The ability to in vitro cholesterol level reduction in laboratory media has been shown for numerous strains of lactic acid bacteria, but not for all strains of lactic bacteria used in the dairy industry. The aim of this work was the determination of the ability of selected thermophilic lactic acid bacteria to cholesterol assimilation during 24 h culture in MRS broth. Commercial starter cultures showed various ability to cholesterol assimilation from laboratory medium. In case of starter cultu...

  4. Structure of cholesterol/ceramide monolayer mixtures

    DEFF Research Database (Denmark)

    Scheffer, L.; Solomonov, I.; Weygand, M.J.; Kjær, K.; Leiserowitz, L.; Addadi, L.

    2005-01-01

    The structure of monolayers of cholesterol/ ceramide mixtures was investigated using grazing incidence x-ray diffraction, immunofluorescence, and atomic force microscopy techniques. Grazing incidence x-ray diffraction measurements showed the existence of a crystalline mixed phase of the two...... was determined and modeled. Immunolabeling was performed with an antibody specific to the cholesterol monohydrate crystalline arrangement. The antibody recognizes crystalline cholesterol monolayers, but does not interact with crystalline ceramide. Immunofluorescence and atomic force microscopy data...

  5. Structure of Cholesterol in Lipid Rafts

    Science.gov (United States)

    Toppozini, Laura; Meinhardt, Sebastian; Armstrong, Clare L.; Yamani, Zahra; Kučerka, Norbert; Schmid, Friederike; Rheinstädter, Maikel C.

    2014-11-01

    Rafts, or functional domains, are transient nano-or mesoscopic structures in the plasma membrane and are thought to be essential for many cellular processes such as signal transduction, adhesion, trafficking, and lipid or protein sorting. Observations of these membrane heterogeneities have proven challenging, as they are thought to be both small and short lived. With a combination of coarse-grained molecular dynamics simulations and neutron diffraction using deuterium labeled cholesterol molecules, we observe raftlike structures and determine the ordering of the cholesterol molecules in binary cholesterol-containing lipid membranes. From coarse-grained computer simulations, heterogenous membranes structures were observed and characterized as small, ordered domains. Neutron diffraction was used to study the lateral structure of the cholesterol molecules. We find pairs of strongly bound cholesterol molecules in the liquid-disordered phase, in accordance with the umbrella model. Bragg peaks corresponding to ordering of the cholesterol molecules in the raftlike structures were observed and indexed by two different structures: a monoclinic structure of ordered cholesterol pairs of alternating direction in equilibrium with cholesterol plaques, i.e., triclinic cholesterol bilayers.

  6. Lysobisphosphatidic acid controls endosomal cholesterol levels.

    Science.gov (United States)

    Chevallier, Julien; Chamoun, Zeina; Jiang, Guowei; Prestwich, Glenn; Sakai, Naomi; Matile, Stefan; Parton, Robert G; Gruenberg, Jean

    2008-10-10

    Most cell types acquire cholesterol by endocytosis of circulating low density lipoprotein, but little is known about the mechanisms of intra-endosomal cholesterol transport and about the primary cause of its aberrant accumulation in the cholesterol storage disorder Niemann-Pick type C (NPC). Here we report that lysobisphosphatidic acid (LBPA), an unconventional phospholipid that is only detected in late endosomes, regulates endosomal cholesterol levels under the control of Alix/AlP1, which is an LBPA-interacting protein involved in sorting into multivesicular endosomes. We find that Alix down-expression decreases both LBPA levels and the lumenal vesicle content of late endosomes. Cellular cholesterol levels are also decreased, presumably because the storage capacity of endosomes is affected and thus cholesterol clearance accelerated. Both lumenal membranes and cholesterol can be restored in Alix knockdown cells by exogenously added LBPA. Conversely, we also find that LBPA becomes limiting upon pathological cholesterol accumulation in NPC cells, because the addition of exogenous LBPA, but not of LBPA isoforms or analogues, partially reverts the NPC phenotype. We conclude that LBPA controls the cholesterol capacity of endosomes. PMID:18644787

  7. Potential of BODIPY-cholesterol for analysis of cholesterol transport and diffusion in living cells

    DEFF Research Database (Denmark)

    Wüstner, Daniel; Lund, Frederik Wendelboe; Röhrl, Clemens;

    2016-01-01

    Cholesterol is an abundant and important lipid component of cellular membranes. Analysis of cholesterol transport and diffusion in living cells is hampered by the technical challenge of designing suitable cholesterol probes which can be detected for example by optical microscopy. One strategy is to...... use intrinsically fluorescent sterols, as dehydroergosterol (DHE), having minimal chemical alteration compared to cholesterol but giving low fluorescence signals in the UV region of the spectrum. Alternatively, one can use dye-tagged cholesterol analogs and in particular BODIPY-cholesterol (BChol......), whose synthesis and initial characterization was pioneered by Robert Bittman. Here, we give a general overview of the properties and applications but also limitations of BODIPY-tagged cholesterol probes for analyzing intracellular cholesterol trafficking. We describe our own experiences and...

  8. Oxidised LDL, HDL cholesterol, LDL cholesterol levels in patients of coronary artery disease

    OpenAIRE

    Ghosh, Joya; T K Mishra; Rao, Y. N.; Aggarwal, S. K.

    2006-01-01

    Coronary artery disease is a major cause of morbidity and has various risk factors. Lipid profile i.e. low HDL-cholesterol, high LDL cholesterol, high total cholesterol, high triglycerides playing important role in its causation. Recently interest has been shown in the oxidized fraction of LDL as one of the risk factors. In the present study 60 age and sex matched normal healthy individuals were taken as controls and 60 patients of CAD were taken. Cholesterol was measured by enzymatic method,...

  9. Mast Cells and HDL Studies on Cholesterol Efflux and Reverse Cholesterol Transport

    OpenAIRE

    Kareinen, Ilona

    2015-01-01

    Atherosclerosis is an inflammatory disease characterized by the accumulation of cholesterol in the arterial intima and consequently the formation of atherosclerotic plaques. Formation of these plaques is initiated by the appearance of macrophage foam cell in the arterial intima. Foam cells are formed as excessive cholesterol accumulates in the cytosol of macrophages and finally the net influx exceeds the efflux of cholesterol. Excessive accumulation of chemically modified cholesterol in foam ...

  10. Intracellular cholesterol-binding proteins enhance HDL-mediated cholesterol uptake in cultured primary mouse hepatocytes

    OpenAIRE

    Storey, Stephen M.; McIntosh, Avery L.; Huang, Huan; Landrock, Kerstin K.; Martin, Gregory G.; Landrock, Danilo; Payne, H. Ross; Atshaves, Barbara P.; Kier, Ann B.; Schroeder, Friedhelm

    2012-01-01

    A major gap in our knowledge of rapid hepatic HDL cholesterol clearance is the role of key intracellular factors that influence this process. Although the reverse cholesterol transport pathway targets HDL to the liver for net elimination of free cholesterol from the body, molecular details governing cholesterol uptake into hepatocytes are not completely understood. Therefore, the effects of sterol carrier protein (SCP)-2 and liver fatty acid-binding protein (L-FABP), high-af...

  11. Lipidomic Approaches towards Deciphering Glycolipids from Microalgae as a Reservoir of Bioactive Lipids.

    Science.gov (United States)

    da Costa, Elisabete; Silva, Joana; Mendonça, Sofia Hoffman; Abreu, Maria Helena; Domingues, Maria Rosário

    2016-05-01

    In recent years, noteworthy research has been performed around lipids from microalgae. Among lipids, glycolipids (GLs) are quite abundant in microalgae and are considered an important source of fatty acids (FAs). GLs are rich in 16- and 18-carbon saturated and unsaturated fatty acids and often contain polyunsaturated fatty acids (PUFAs) like n-3 α-linolenic (ALA 18:3), eicosapentaenoic (EPA, 20:5) and docosahexaenoic (DHA, 22:6). GLs comprise three major classes: monogalactosyldiacyl glycerolipids (MGDGs), digalactosyl diacylglycerolipids (DGDGs) and sulfoquinovosyl diacylglycerolipids (SQDGs), whose composition in FA directly depends on the growth conditions. Some of these lipids are high value-added compounds with antitumoral, antimicrobial and anti-inflammatory activities and also with important nutritional significance. To fully explore GLs' bioactive properties it is necessary to fully characterize their structure and to understand the relation between the structure and their biological properties, which can be addressed using modern mass spectrometry (MS)-based lipidomic approaches. This review will focus on the up-to-date FA composition of GLs identified by MS-based lipidomics and their potential as phytochemicals. PMID:27213410

  12. Evidence that a glycolipid tail anchors antigen 117 to the plasma membrane of Dictyostelium discoideum cells

    International Nuclear Information System (INIS)

    The authors describe the biochemical features of the putative cell cohesion molecule antigen 117, indicating that it is anchored to the plasma membrane by a glycolipid tail. Antigen 117 can be radiolabeled with [3H]myristate, [3H]palmitate, and [14C]ethanolamine. The fatty acid label is removed by periodate oxidation and nitrous acid deamination, indicating that the fatty acid is attached to the protein by a structure containing carbohydrate and an unsubstituted glucosamine. As cells develop aggregation competence, the antigen is released from the cell surface in a soluble form that can still be radiolabeled with [14C]ethanolamine but not with [3H]myristate of [3H]-palmitate. The molecular weight of the released antigen is similar to that found in the plasma membrane, but it preferentially partitions in Triton X-114 as a hydrophilic, as opposed to a hydrophobic, protein. Plasma membranes contain the enzyme activity responsible for the release of the antigen in a soluble form

  13. Mycoplasma fermentans glycolipid-antigen as a pathogen of rheumatoid arthritis

    International Nuclear Information System (INIS)

    Mycoplasma fermentans has been suspected as one of the causative pathogenic microorganisms of rheumatoid arthritis (RA) however, the pathogenic mechanism is still unclear. We, previously, reported that glycolipid-antigens (GGPL-I and III) are the major antigens of M. fermentans. Monoclonal antibody against the GGPL-III could detect the existence of the GGPL-III antigens in synovial tissues from RA patients. GGPL-III antigens were detected in 38.1% (32/84) of RA patient's tissues, but not in osteoarthritis (OA) and normal synovial tissues. Immunoelectron microscopy revealed that a part of GGPL-III antigens are located at endoplasmic reticulum. GGPL-III significantly induced TNF-α and IL-6 production from peripheral blood mononulear cells, and also proliferation of synovial fibroblasts. Further study is necessary to prove that M. fermentans is a causative microorganism of RA; however, the new mechanisms of disease pathogenesis provides hope for the development of effective and safe immunotherapeutic strategies based on the lipid-antigen, GGPL-III, in the near future

  14. Lipidomic Approaches towards Deciphering Glycolipids from Microalgae as a Reservoir of Bioactive Lipids

    Science.gov (United States)

    da Costa, Elisabete; Silva, Joana; Mendonça, Sofia Hoffman; Abreu, Maria Helena; Domingues, Maria Rosário

    2016-01-01

    In recent years, noteworthy research has been performed around lipids from microalgae. Among lipids, glycolipids (GLs) are quite abundant in microalgae and are considered an important source of fatty acids (FAs). GLs are rich in 16- and 18-carbon saturated and unsaturated fatty acids and often contain polyunsaturated fatty acids (PUFAs) like n-3 α-linolenic (ALA 18:3), eicosapentaenoic (EPA, 20:5) and docosahexaenoic (DHA, 22:6). GLs comprise three major classes: monogalactosyldiacyl glycerolipids (MGDGs), digalactosyl diacylglycerolipids (DGDGs) and sulfoquinovosyl diacylglycerolipids (SQDGs), whose composition in FA directly depends on the growth conditions. Some of these lipids are high value-added compounds with antitumoral, antimicrobial and anti-inflammatory activities and also with important nutritional significance. To fully explore GLs’ bioactive properties it is necessary to fully characterize their structure and to understand the relation between the structure and their biological properties, which can be addressed using modern mass spectrometry (MS)-based lipidomic approaches. This review will focus on the up-to-date FA composition of GLs identified by MS-based lipidomics and their potential as phytochemicals. PMID:27213410

  15. Lipidomic Approaches towards Deciphering Glycolipids from Microalgae as a Reservoir of Bioactive Lipids

    Directory of Open Access Journals (Sweden)

    Elisabete da Costa

    2016-05-01

    Full Text Available In recent years, noteworthy research has been performed around lipids from microalgae. Among lipids, glycolipids (GLs are quite abundant in microalgae and are considered an important source of fatty acids (FAs. GLs are rich in 16- and 18-carbon saturated and unsaturated fatty acids and often contain polyunsaturated fatty acids (PUFAs like n-3 α-linolenic (ALA 18:3, eicosapentaenoic (EPA, 20:5 and docosahexaenoic (DHA, 22:6. GLs comprise three major classes: monogalactosyldiacyl glycerolipids (MGDGs, digalactosyl diacylglycerolipids (DGDGs and sulfoquinovosyl diacylglycerolipids (SQDGs, whose composition in FA directly depends on the growth conditions. Some of these lipids are high value-added compounds with antitumoral, antimicrobial and anti-inflammatory activities and also with important nutritional significance. To fully explore GLs’ bioactive properties it is necessary to fully characterize their structure and to understand the relation between the structure and their biological properties, which can be addressed using modern mass spectrometry (MS-based lipidomic approaches. This review will focus on the up-to-date FA composition of GLs identified by MS-based lipidomics and their potential as phytochemicals.

  16. Characterization of the genus Pseudozyma by the formation of glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Hiroko K; Kitamoto, Dai

    2007-03-01

    Pseudozyma antarctica is one of the best producers of the glycolipid biosurfactants known as mannosylerythritol lipids (MELs), which show not only excellent surface-active properties but also versatile biochemical actions. In order to obtain a variety of producers, all the species of the genus were examined for their production of MELs from soybean oil. Pseudozyma fusiformata, P. parantarctica and P. tsukubaensis were newly identified to be MEL producers. Of the strains tested, P. parantarctica gave the best yield of MELs (30 g L(-1)). The obtained yield corresponded to those of P. antarctica, P. aphidis and P. rugulosa, which are known high-level MEL producers. Interestingly, P. parantarctica and P. fusiformata produced mainly 4-O-[(4',6'-di-O-acetyl-2',3'-di-O-alkanoyl)-beta-d-mannopyranosyl]-meso-erythritol (MEL-A), whereas P. tsukubaensis produced mainly 4-O-[(6'-mono-O-acetyl-2',3'-di-O-alkanoyl)-beta-d-mannopyranosyl]-meso-erythritol (MEL-B). Consequently, six of the nine species clearly produced MELs. Based on the MEL production pattern, the nine species seemed to fall into four groups: the first group produces large amounts of MELs; the second produces both MELs and other biosurfactants; the third mainly produces MEL-B; and the fourth is non-MEL-producing. Thus, MEL production may be an important taxonomic index for the Pseudozyma yeasts. PMID:17328742

  17. Activation of fibroblast and papilla cells by glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Kitagawa, Masaru; Yamamoto, Shuhei; Suzuki, Michiko; Sogabe, Atsushi; Imura, Tomohiro; Fukuoka, Tokuma; Kitamoto, Dai

    2010-01-01

    Mannosylerythritol lipids (MELs), the extracellular glycolipids produced from feedstock by yeasts belonging to the genus Pseudozyma, are the most promising biosurfactants known due to its versatile interfacial and biochemical actions. In order to broaden the application in cosmetics, the cell activating property of MELs was investigated using cultured fibroblast and papilla cells, and a three-dimensional cultured human skin model. The di-acetylated MEL (MEL-A) produced from soybean oil significantly increased the viability of the fibroblast cells over 150% compared with that of control cells. On the other hand, no cell activation was observed by the treatment with MEL-A produced from olive oil. The mono-acetylated MEL (MEL-B) hardly increased the cell viability. The viability of the fibroblast cells decreased with the addition of more than 1 microg/L of MELs, whereas the cultured human skin cells showed high viability with 5 microg/L of MELs. Interestingly, the papilla cells were dramatically activated with 0.001 microg/L of MEL-A produced from soybean oil: the cell viability reached at 150% compared with that of control cells. Consequently, the present MEL-A produced from soybean oil should have a potential as a new hair growth agent stimulating the papilla cells. PMID:20625237

  18. Dietary cholesterol and fats at a young age : do they influence cholesterol metabolism in adult life?

    NARCIS (Netherlands)

    Temmerman, A M; Vonk, R J; Niezen-Koning, K; Berger, R.; Fernandes, J

    1989-01-01

    The effects of dietary cholesterol and fats on cholesterol metabolism later in life were studied in Mongolian gerbils. Three groups were given a basic diet with soybean oil, palm kernel oil amounting to 8.75% (w/w), or the basic diet only. In three other groups, cholesterol (0.05%) was added to the

  19. From blood to gut : Direct secretion of cholesterol via transintestinal cholesterol efflux

    NARCIS (Netherlands)

    Vrins, Carlos L. J.

    2010-01-01

    The reverse cholesterol transport pathway (RCT) is the focus of many cholesterol lowering therapies By way of this pathway, excess cholesterol is collected from peripheral tissues and delivered back to the liver and gastrointestinal tract for excretion from the body For a long time this removal via

  20. Statins increase hepatic cholesterol synthesis and stimulate fecal cholesterol elimination in mice

    NARCIS (Netherlands)

    Schonewille, Marleen; de Boer, Jan Freark; Mele, Laura; Wolters, Henk; Bloks, Vincent W; Wolters, Justina C; Kuivenhoven, Jan Albert; Tietge, Uwe J.F.; Brufau Dones, Gemma; Groen, Albert K

    2016-01-01

    Statins are competitive inhibitors of HMG-CoA reductase, the rate-limiting enzyme of cholesterol synthesis. Statins reduce plasma cholesterol levels, but whether this is actually caused by inhibition of de novo cholesterol synthesis has not been clearly established. Using three different statins we

  1. Toxin A from Clostridium difficile binds to rabbit erythrocyte glycolipids with terminal Gal alpha 1-3Gal beta 1-4GlcNAc sequences

    International Nuclear Information System (INIS)

    The binding of Toxin A isolated from Clostridium difficile to rabbit erythrocyte glycolipids has been studied. Total lipid extracts from rabbit erythrocytes were subjected to thin-layer chromatography and toxin-binding glycolipids detected by using 125I-labeled Toxin A in a direct binding overlay technique. Two major and several minor toxin-binding glycolipids were detected in rabbit erythrocytes by this method. The results of structural analyses of the major toxin-binding glycolipids were consistent with a pentasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) and a branched decasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3[Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-6]Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) previously identified as the two most abundant glycolipids in rabbit erythrocytes. 125I-Toxin A binding to these glycolipids could be inhibited by bovine thyroglobulin, monospecific antiserum to the toxin, or by treatment of the glycolipids with alpha-galactosidase. The absence of toxin interaction with isoglobotriaosylceramide (Gal alpha 1-3Gal beta 1-4Glc-Cer) isolated from canine intestine suggested that the GlcNAc residue present in the terminal Gal alpha 1-3Gal beta 1-4GLcNAc sequence common to all known toxin binding glycoconjugates is required for carbohydrate-specific recognition by Toxin A. These observations are consistent with the proposed carbohydrate binding specificity of Toxin A for the nonreducing terminal sequence, Gal alpha 1-3Gal beta 1-4GlcNAc

  2. Toxin A from Clostridium difficile binds to rabbit erythrocyte glycolipids with terminal Gal alpha 1-3Gal beta 1-4GlcNAc sequences

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.F.; Krivan, H.C.; Wilkins, T.D.; Smith, D.F.

    1987-08-15

    The binding of Toxin A isolated from Clostridium difficile to rabbit erythrocyte glycolipids has been studied. Total lipid extracts from rabbit erythrocytes were subjected to thin-layer chromatography and toxin-binding glycolipids detected by using /sup 125/I-labeled Toxin A in a direct binding overlay technique. Two major and several minor toxin-binding glycolipids were detected in rabbit erythrocytes by this method. The results of structural analyses of the major toxin-binding glycolipids were consistent with a pentasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) and a branched decasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3(Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-6)Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) previously identified as the two most abundant glycolipids in rabbit erythrocytes. /sup 125/I-Toxin A binding to these glycolipids could be inhibited by bovine thyroglobulin, monospecific antiserum to the toxin, or by treatment of the glycolipids with alpha-galactosidase. The absence of toxin interaction with isoglobotriaosylceramide (Gal alpha 1-3Gal beta 1-4Glc-Cer) isolated from canine intestine suggested that the GlcNAc residue present in the terminal Gal alpha 1-3Gal beta 1-4GLcNAc sequence common to all known toxin binding glycoconjugates is required for carbohydrate-specific recognition by Toxin A. These observations are consistent with the proposed carbohydrate binding specificity of Toxin A for the nonreducing terminal sequence, Gal alpha 1-3Gal beta 1-4GlcNAc.

  3. Phase I study to evaluate toxicity and feasibility of intratumoral injection of α-gal glycolipids in patients with advanced melanoma.

    Science.gov (United States)

    Albertini, Mark R; Ranheim, Erik A; Zuleger, Cindy L; Sondel, Paul M; Hank, Jacquelyn A; Bridges, Alan; Newton, Michael A; McFarland, Thomas; Collins, Jennifer; Clements, Erin; Henry, Mary Beth; Neuman, Heather B; Weber, Sharon; Whalen, Giles; Galili, Uri

    2016-08-01

    Effective uptake of tumor cell-derived antigens by antigen-presenting cells is achieved pre-clinically by in situ labeling of tumor with α-gal glycolipids that bind the naturally occurring anti-Gal antibody. We evaluated toxicity and feasibility of intratumoral injections of α-gal glycolipids as an autologous tumor antigen-targeted immunotherapy in melanoma patients (pts). Pts with unresectable metastatic melanoma, at least one cutaneous, subcutaneous, or palpable lymph node metastasis, and serum anti-Gal titer ≥1:50 were eligible for two intratumoral α-gal glycolipid injections given 4 weeks apart (cohort I: 0.1 mg/injection; cohort II: 1.0 mg/injection; cohort III: 10 mg/injection). Monitoring included blood for clinical, autoimmune, and immunological analyses and core tumor biopsies. Treatment outcome was determined 8 weeks after the first α-gal glycolipid injection. Nine pts received two intratumoral injections of α-gal glycolipids (3 pts/cohort). Injection-site toxicity was mild, and no systemic toxicity or autoimmunity could be attributed to the therapy. Two pts had stable disease by RECIST lasting 8 and 7 months. Tumor nodule biopsies revealed minimal to no change in inflammatory infiltrate between pre- and post-treatment biopsies except for 1 pt (cohort III) with a post-treatment inflammatory infiltrate. Two and four weeks post-injection, treated nodules in 5 of 9 pts exhibited tumor cell necrosis without neutrophilic or lymphocytic inflammatory response. Non-treated tumor nodules in 2 of 4 evaluable pts also showed necrosis. Repeated intratumoral injections of α-gal glycolipids are well tolerated, and tumor necrosis was seen in some tumor nodule biopsies after tumor injection with α-gal glycolipids. PMID:27207605

  4. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  5. Power-constrained supercomputing

    Science.gov (United States)

    Bailey, Peter E.

    As we approach exascale systems, power is turning from an optimization goal to a critical operating constraint. With power bounds imposed by both stakeholders and the limitations of existing infrastructure, achieving practical exascale computing will therefore rely on optimizing performance subject to a power constraint. However, this requirement should not add to the burden of application developers; optimizing the runtime environment given restricted power will primarily be the job of high-performance system software. In this dissertation, we explore this area and develop new techniques that extract maximum performance subject to a particular power constraint. These techniques include a method to find theoretical optimal performance, a runtime system that shifts power in real time to improve performance, and a node-level prediction model for selecting power-efficient operating points. We use a linear programming (LP) formulation to optimize application schedules under various power constraints, where a schedule consists of a DVFS state and number of OpenMP threads for each section of computation between consecutive message passing events. We also provide a more flexible mixed integer-linear (ILP) formulation and show that the resulting schedules closely match schedules from the LP formulation. Across four applications, we use our LP-derived upper bounds to show that current approaches trail optimal, power-constrained performance by up to 41%. This demonstrates limitations of current systems, and our LP formulation provides future optimization approaches with a quantitative optimization target. We also introduce Conductor, a run-time system that intelligently distributes available power to nodes and cores to improve performance. The key techniques used are configuration space exploration and adaptive power balancing. Configuration exploration dynamically selects the optimal thread concurrency level and DVFS state subject to a hardware-enforced power bound

  6. Inherited Cholesterol Disorder Significantly Boosts Heart Risks

    Science.gov (United States)

    ... leaves her cholesterol untreated, her risk of coronary heart disease death or nonfatal heart attack would be comparable to ... Recent Health News Related MedlinePlus Health Topics Cholesterol Heart Diseases--Prevention ... Us Get email updates Subscribe to RSS Follow us ...

  7. Computational model for monitoring cholesterol metabolism.

    Science.gov (United States)

    Selvakumar, R; Rashith Muhammad, M; Poornima Devi, G

    2014-12-01

    A non-deterministic finite automaton is designed to observe the cholesterol metabolism with the states of acceptance and rejection. The acceptance state of the automaton depicts the normal level of metabolism and production of good cholesterol as an end product. The rejection state of this machine shows the inhibition of enzymatic activity in cholesterol synthesis and removal of free fatty acids. The deficiency in human cholesterol metabolism pathway results in abnormal accumulation of cholesterol in plasma, arterial tissues leading to diseases such as hypercholesterolemia, atherosclerosis respectively and formation of gallstones. The designed machine can be used to monitor the cholesterol metabolism at molecular level through regulation of enzymes involved in the biosynthesis and metabolism of cholesterol for the treatment of diseases incident due to the respective metabolic disorder. In addition, an algorithm for this machine has been developed to compare the programmed string with the given string. This study demonstrates the construction of a machine that is used for the development of molecular targeted therapy for the disorders in cholesterol metabolism. PMID:26396654

  8. Cholesterol modulates bitter taste receptor function.

    Science.gov (United States)

    Pydi, Sai Prasad; Jafurulla, Md; Wai, Lisa; Bhullar, Rajinder P; Chelikani, Prashen; Chattopadhyay, Amitabha

    2016-09-01

    Bitter taste perception in humans is believed to act as a defense mechanism against ingestion of potential toxic substances. Bitter taste is perceived by 25 distinct bitter taste receptors (T2Rs) which belong to the family of G protein-coupled receptors (GPCRs). In the overall context of the role of membrane lipids in GPCR function, we show here that T2R4, a representative member of the bitter taste receptor family, displays cholesterol sensitivity in its signaling function. In order to gain further insight into cholesterol sensitivity of T2R4, we mutated two residues Tyr114(3.59) and Lys117(3.62) present in the cholesterol recognition amino acid consensus (CRAC) motif in T2R4 with alanines. We carried out functional characterization of the mutants by calcium mobilization, followed by cholesterol depletion and replenishment. CRAC motifs in GPCRs have previously been implicated in preferential cholesterol association. Our analysis shows that the CRAC motif represents an intrinsic feature of bitter taste receptors and is conserved in 22 out of 25 human T2Rs. We further demonstrate that Lys117, an important CRAC residue, is crucial in the reported cholesterol sensitivity of T2R4. Interestingly, cholesterol sensitivity of T2R4 was observed at quinine concentrations in the lower mM range. To the best of our knowledge, our results represent the first report addressing the molecular basis of cholesterol sensitivity in the function of taste receptors. PMID:27288892

  9. Biliary cholesterol excretion: A novel mechanism that regulates dietary cholesterol absorption

    OpenAIRE

    Sehayek, Ephraim; Ono, Jennie G.; Shefer, Sarah; Nguyen, Lien B.; Wang, Nan; Batta, Ashok K.; Salen, Gerald; Smith, Jonathan D.; Tall, Alan R.; Breslow, Jan L.

    1998-01-01

    The regulation of dietary cholesterol absorption was examined in C57BL/6 and transgenic mice with liver overexpression of the scavenger receptor BI (SR-BI Tg). In C57BL/6 animals, feeding 0.02 to 1% (wt/wt) dietary cholesterol resulted in a dose-dependent decrease in the percentage of dietary cholesterol absorbed. A plot of total daily mass of dietary cholesterol absorbed versus the percentage by weight of cholesterol in the diet yielded a curve suggesting a saturable process with a Km of 0.4...

  10. The Structure of Cholesterol in Lipid Rafts

    CERN Document Server

    Toppozini, Laura; Armstrong, Clare L; Yamani, Zahra; Kucerka, Norbert; Schmid, Friederike; Rheinstaedter, Maikel C

    2014-01-01

    Rafts, or functional domains, are transient nano- or mesoscopic structures in the plasma membrane and are thought to be essential for many cellular processes such as signal transduction, adhesion, trafficking and lipid/protein sorting. Observations of these membrane heterogeneities have proven challenging, as they are thought to be both small and short-lived. With a combination of coarse-grained molecular dynamics simulations and neutron diffraction using deuterium labeled cholesterol molecules we observe raft-like structures and determine the ordering of the cholesterol molecules in binary cholesterol-containing lipid membranes. From coarse-grained computer simulations, heterogenous membranes structures were observed and characterized as small, ordered domains. Neutron diffraction was used to study the lateral structure of the cholesterol molecules. We find pairs of strongly bound cholesterol molecules in the liquid-disordered phase, in accordance with the umbrella model. Bragg peaks corresponding to orderin...

  11. Trapping crystal nucleation of cholesterol monohydrate

    DEFF Research Database (Denmark)

    Solomonov, I.; Weygand, M.J.; Kjær, K.;

    2005-01-01

    Crystalline nucleation of cholesterol at the air-water interface has been studied via grazing incidence x-ray diffraction using synchrotron radiation. The various stages of cholesterol molecular assembly from monolayer to three bilayers incorporating interleaving hydrogen-bonded water layers in a...... monoclinic cholesterol . H2O phase, has been monitored and their structures characterized to near atomic resolution. Crystallographic evidence is presented that this multilayer phase is similar to that of a reported metastable cholesterol phase of undetermined structure obtained from bile before...... transformation to the triclinic phase of cholesterol . H2O, the thermodynamically stable macroscopic form. According to grazing incidence x-ray diffraction measurements and crystallographic data, a transformation from the monoclinic film structure to a multilayer of the stable monohydrate phase involves, at...

  12. Major Risk Factors for Heart Disease: High Blood Cholesterol

    Science.gov (United States)

    ... Major Risk Factors for Heart Disease High Blood Cholesterol High blood cholesterol is another major risk factor for heart disease ... can do something about. The higher your blood cholesterol level, the greater your risk for developing heart ...

  13. High Blood Cholesterol: What You Need to Know

    Science.gov (United States)

    ... Audiences Contact The Health Information Center High Blood Cholesterol: What You Need To Know Table of Contents ... Lifestyle Changes (TLC) Drug Treatment Resources Why Is Cholesterol Important? Your blood cholesterol level has a lot ...

  14. Endogenous cholesterol synthesis, fecal steroid excretion and serum lanosterol in subjects with high or low response of serum cholesterol to dietary cholesterol

    NARCIS (Netherlands)

    Beynen, A.C.; Katan, M.B.; Gent, van C.M.

    1986-01-01

    In this study we addressed the question whether hypo- and hyper-responders to dietary cholesterol differ with regard to the flexibility of endogenous cholesterol synthesis after changes in cholesterol intake. Whole-body cholesterol synthesis was measured as faecal excretion of neutral steroids and b

  15. Production of glycolipidic bio surfactants by environment bacteria: diversity and physiological part; Production de biosurfactants glycolipidiques par les bacteries de l`environnement: diversite et role physiologique

    Energy Technology Data Exchange (ETDEWEB)

    Arino, S.

    1996-10-09

    About a hundred bacterial strains, isolated from soils, polluted or not by hydrocarbons, were tested for their capacity to excrete glycosides. The biggest productions were obtained for a soluble carbon source (glycerol) in a culture medium limited in the nitrogen source. In these conditions, 18 g/l of rhamnose lipids were produced by train Pseudomonas aeruginosa GL1 in a 200 h culture. Pseudomonas aeruginosa GL1, Cellulomonas celulans SA43 and Rhodococcus erythropolis DSM 43060 were studied in detail. The bio-surfactants produced were identified respectively as rhamnose lipids, oligosaccharide lipids and trehalose lipids, using various original analytical methods. Sugars and fatty acids composing these glycolipids had been shown to be usual components of the outer part of the cell wall in these microbial species. Moreover, cell hydrophobicity of the producing bacteria varied in time during culture. These results showed that both the cell wall and the extracellular glycolipids take part in the process of hydrocarbon uptake in the polluted environments. As other bacteria of the same species from different origins present the same characteristics, it may be concluded that glycolipid excretion does not constitute a specific response for hydrocarbon assimilation. In fact, a more general physiological role of glycolipids, concerning modifications of hydrophobic interfaces between the producing bacteria and their surrounding environment, could explain the production of glycolipids, and could also be utilized in hydrocarbon uptake. (author)

  16. Current relevance of fungal and trypanosomatid glycolipids and sphingolipids: studies defining structures conspicuously absent in mammals

    Directory of Open Access Journals (Sweden)

    Helio K. Takahashi

    2009-09-01

    Full Text Available Recently, glycosphingolipids have been attracting attention due to their role on biological systems as second messengers or modulators of signal transduction, affecting several events, which range from apoptosis to regulation of the cell cycle. In pathogenic fungi, glycolipids are expressed in two classes: neutral monohexosylceramides (glucosyl-or galactosylceramide and acidic glycosylinositol phosphorylceramides (the latter class carries longer glycan chains. It is worth to mention that monohexosylceramides exhibit significant structural differences in their lipid moieties compared to their mammalian counterparts, whereas the glycosylinositol phosphorylceramides exhibit remarkable structural differences in their carbohydrate moieties in comparison to mammal glycosphingolipids counterpart. We observed that glycosylinositol phosphorylceramides are capable of promoting immune response in infected humans. In addition, inhibiting fungal glycosphingolipid biosynthetic pathways leads to an inhibition of colony formation, spore germination, cell cycle, dimorphism and hyphal growth. Other pathogens, such as trypanosomatids, also present unique glycolipids, which may have an important role for the parasite development and/or disease establishment. Regarding host-pathogen interaction, cell membrane rafts, which are enriched in sphingolipids and sterols, participate in parasite/fungal infection. In this review, it is discussed the different biological roles of (glyco (sphingolipids of pathogenic/opportunistic fungi and trypanosomatids.Recentemente, glicoesfingolipídeos têm atraído atenção devido ao seu papel na biologia celular como segundo-mensageiro ou moduladores da transdução de sinal, afetando vários eventos, desde apoptose até a regulação do ciclo celular. Em fungos patogênicos, existem duas classes de glicolipídeos: monohexosil ceramidas neutras (glucosil-ou galactosilceramida e glicosilinositol fosforilceramidas (os quais apresentam

  17. The Structural Basis of Cholesterol Accessibility in Membranes

    OpenAIRE

    Olsen, Brett N.; Bielska, Agata A.; Lee, Tiffany; Daily, Michael D.; Covey, Douglas F.; Schlesinger, Paul H.; Baker, Nathan A.; Ory, Daniel S.

    2013-01-01

    Although the majority of free cellular cholesterol is present in the plasma membrane, cholesterol homeostasis is principally regulated through sterol-sensing proteins that reside in the cholesterol-poor endoplasmic reticulum (ER). In response to acute cholesterol loading or depletion, there is rapid equilibration between the ER and plasma membrane cholesterol pools, suggesting a biophysical model in which the availability of plasma membrane cholesterol for trafficking to internal membranes mo...

  18. Antibodies to the neutral glycolipid asialo ganglio-N-tetraosylceramide: association with gynecologic cancers.

    Science.gov (United States)

    Witkin, S S; Bongiovanni, A M; Birnbaum, S; Caputo, T; Ledger, W J

    1985-03-01

    As part of our efforts to define subpopulations at increased risk for gynecologic malignancies, sera from 145 women were obtained prior to diagnosis and analyzed for antibody to asialo ganglio-N-tetraosylceramide. This neutral glycolipid is present on the surface of thymocytes and natural killer cells, and asialo ganglio-N-tetraosylceramide antibody has been shown in animals to block natural killer cell activity and promote tumor cell proliferation. With the use of an enzyme-linked immunosorbent assay and with a value of 2 SD above the mean for healthy women designated as the boundary for a positive response, antibody to asialo ganglio-N-tetraosylceramide was detected in only one of 30 (3%) healthy women, none of 16 pregnant women, none of 18 women with benign masses, and two of 24 (8%) women with microbial infections. All of the above samples that contained antibodies were barely over the 2 SD limit. In marked contrast, 19 of 35 (54%) women with gynecologic malignancies had asialo ganglio-N-tetraosylceramide antibodies, with positive values ranging to greater than 10 SD above the control mean. Asialo ganglio-N-tetraosylceramide antibody was found in six of eight (75%) patients with cervical cancer, five of eight (63%) with endometrial cancer, and seven of 15 (47%) with ovarian cancer. Of the eight patients with Stage I gynecologic cancer at any site, five (62%) had asialo ganglio-N-tetraosylceramide antibodies. Four of 22 (18%) women with Hodgkin's disease also had antibodies, with values just exceeding 2 SD above control levels. The presence of these antibodies may contribute to an impaired immune surveillance system in these women and so increase their susceptibility to malignancy. PMID:3976767

  19. Genome and transcriptome analysis of the basidiomycetous yeast Pseudozyma antarctica producing extracellular glycolipids, mannosylerythritol lipids.

    Directory of Open Access Journals (Sweden)

    Tomotake Morita

    Full Text Available Pseudozyma antarctica is a non-pathogenic phyllosphere yeast known as an excellent producer of mannosylerythritol lipids (MELs, multi-functional extracellular glycolipids, from vegetable oils. To clarify the genetic characteristics of P. antarctica, we analyzed the 18 Mb genome of P. antarctica T-34. On the basis of KOG analysis, the number of genes (219 genes categorized into lipid transport and metabolism classification in P. antarctica was one and a half times larger than that of yeast Saccharomyces cerevisiae (140 genes. The gene encoding an ATP/citrate lyase (ACL related to acetyl-CoA synthesis conserved in oleaginous strains was found in P. antarctica genome: the single ACL gene possesses the four domains identical to that of the human gene, whereas the other oleaginous ascomycetous species have the two genes covering the four domains. P. antarctica genome exhibited a remarkable degree of synteny to U. maydis genome, however, the comparison of the gene expression profiles under the culture on the two carbon sources, glucose and soybean oil, by the DNA microarray method revealed that transcriptomes between the two species were significantly different. In P. antarctica, expression of the gene sets relating fatty acid metabolism were markedly up-regulated under the oily conditions compared with glucose. Additionally, MEL biosynthesis cluster of P. antarctica was highly expressed regardless of the carbon source as compared to U. maydis. These results strongly indicate that P. antarctica has an oleaginous nature which is relevant to its non-pathogenic and MEL-overproducing characteristics. The analysis and dataset contribute to stimulate the development of improved strains with customized properties for high yield production of functional bio-based materials.

  20. Genome and transcriptome analysis of the basidiomycetous yeast Pseudozyma antarctica producing extracellular glycolipids, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Koike, Hideaki; Hagiwara, Hiroko; Ito, Emi; Machida, Masayuki; Sato, Shun; Habe, Hiroshi; Kitamoto, Dai

    2014-01-01

    Pseudozyma antarctica is a non-pathogenic phyllosphere yeast known as an excellent producer of mannosylerythritol lipids (MELs), multi-functional extracellular glycolipids, from vegetable oils. To clarify the genetic characteristics of P. antarctica, we analyzed the 18 Mb genome of P. antarctica T-34. On the basis of KOG analysis, the number of genes (219 genes) categorized into lipid transport and metabolism classification in P. antarctica was one and a half times larger than that of yeast Saccharomyces cerevisiae (140 genes). The gene encoding an ATP/citrate lyase (ACL) related to acetyl-CoA synthesis conserved in oleaginous strains was found in P. antarctica genome: the single ACL gene possesses the four domains identical to that of the human gene, whereas the other oleaginous ascomycetous species have the two genes covering the four domains. P. antarctica genome exhibited a remarkable degree of synteny to U. maydis genome, however, the comparison of the gene expression profiles under the culture on the two carbon sources, glucose and soybean oil, by the DNA microarray method revealed that transcriptomes between the two species were significantly different. In P. antarctica, expression of the gene sets relating fatty acid metabolism were markedly up-regulated under the oily conditions compared with glucose. Additionally, MEL biosynthesis cluster of P. antarctica was highly expressed regardless of the carbon source as compared to U. maydis. These results strongly indicate that P. antarctica has an oleaginous nature which is relevant to its non-pathogenic and MEL-overproducing characteristics. The analysis and dataset contribute to stimulate the development of improved strains with customized properties for high yield production of functional bio-based materials. PMID:24586250

  1. Direct xylan conversion into glycolipid biosurfactants, mannosylerythritol lipids, by Pseudozyma antarctica PYCC 5048(T).

    Science.gov (United States)

    Faria, Nuno Torres; Marques, Susana; Fonseca, César; Ferreira, Frederico Castelo

    2015-04-01

    Mannosylerythritol lipids (MEL) are glycolipid biosurfactants, produced by Pseudozyma spp., with increasing commercial interest. While MEL can be produced from d-glucose and d-xylose, the direct conversion of the respective lignocellulosic polysaccharides, cellulose and xylan, was not reported yet. The ability of Pseudozyma antarctica PYCC 5048(T) and Pseudozyma aphidis PYCC 5535(T) to use cellulose (Avicel(®)) and xylan (beechwood) as carbon and energy source has been assessed along with their capacity of producing cellulolytic and hemicellulolytic enzymes, toward a consolidated bioprocess (CBP) for MEL production. The yeasts assessed were neither able to grow in medium containing Avicel(®) nor produce cellulolytic enzymes under the conditions tested. On contrary, both yeasts were able to efficiently grow in xylan, but MEL production was only detected in P. antarctica PYCC 5048(T) cultures. MEL titers reached 1.3g/l after 10 days in batch cultures with 40g/l xylan, and 2.0g/l in fed-batch cultures with xylan feeding (additional 40g/l) at day 4. High levels of xylanase activities were detected in xylan cultures, reaching 47-62U/ml (31-32U/mg) at 50°C, and still exhibiting more than 10U/ml under physiological temperature (28°C). Total β-xylosidase activities, displayed mainly as wall-bounded and extracellular activity, accounted for 0.154 and 0.176U/ml in P. antarctica PYCC 5048(T) and P. aphidis PYCC 5535(T) cultures, respectively. The present results demonstrate the potential of Pseudozyma spp. for using directly a fraction of lignocellulosic biomass, xylan, and combining in the same bioprocess the production of xylanolytic enzymes with MEL production. PMID:25765311

  2. Perturbed cholesterol homeostasis in aging spinal cord.

    Science.gov (United States)

    Parkinson, Gemma M; Dayas, Christopher V; Smith, Doug W

    2016-09-01

    The spinal cord is vital for the processing of sensorimotor information and for its propagation to and from both the brain and the periphery. Spinal cord function is affected by aging, however, the mechanisms involved are not well-understood. To characterize molecular mechanisms of spinal cord aging, microarray analyses of gene expression were performed on cervical spinal cords of aging rats. Of the metabolic and signaling pathways affected, cholesterol-associated pathways were the most comprehensively altered, including significant downregulation of cholesterol synthesis-related genes and upregulation of cholesterol transport and metabolism genes. Paradoxically, a significant increase in total cholesterol content was observed-likely associated with cholesterol ester accumulation. To investigate potential mechanisms for the perturbed cholesterol homeostasis, we quantified the expression of myelin and neuroinflammation-associated genes and proteins. Although there was minimal change in myelin-related expression, there was an increase in phagocytic microglial and astrogliosis markers, particularly in the white matter. Together, these results suggest that perturbed cholesterol homeostasis, possibly as a result of increased inflammatory activation in spinal cord white matter, may contribute to impaired spinal cord function with aging. PMID:27459933

  3. Brain cholesterol in normal and pathological aging

    Directory of Open Access Journals (Sweden)

    Vanmierlo Tim

    2011-07-01

    Full Text Available Aberrations in cerebral cholesterol homeostasis can lead to severe neurological diseases. Recent findings strengthen the link between brain cholesterol metabolism and factors involved in synaptic plasticity, a process essential for learning and memory functions, as well as regeneration, which are affected in Alzheimer’s Disease (AD. Cholesterol homeostasis within the brain is independent of that in the rest of the body and needs to be strictly regulated for optimal brain functioning. In contrast with what was initially assumed brain cholesterol homeostasis can be modulated by extra-cerebral factors. We have found that enhancement of the cholesterol-turnover in the brain by administration of the synthetic activator of liver x receptos (LXRs, T0901317, leads to restoration of memory functions in an AD mouse-model.Memory in C57Bl6NCrl mice was not further improved by the same treatment. Moreover, it was found that in contrast with cholesterol, the structurally very similar dietary derived plant sterols can enter the brain. Plant sterols may be natural activators of LXRs. Evidence is provided suggesting that brassicasterol may be a novel additional biomarker in cerebrospinal fluid of AD patients. Insight into the regulation of cerebral cholesterol homeostasis will provide possibilities to modulate the key steps involved and may lead to the development of therapies for the prevention as well as treatment of neurodegenerative diseases such as AD.

  4. Cholesterol esterase activity of human intestinal mucosa

    International Nuclear Information System (INIS)

    It has been suggested that cholesterol absorption in humans is dependent on bile acid pool composition and that expansion of the cholic acid pool size is followed by an increase of the absorption values. Similar observations were reported in rats. In the present study, therefore, the authors investigated some general properties of human intestinal cholesterol esterase, with particular emphasis on the effect of bile acids on this enzymatic activity. Twenty-nine segments of small intestine were taken during operations; the enzymatic activity was studied by using mucosal homogenate as a source of enzyme and oleic acid, cholesterol, and 14C-labeled cholesterol as substrates. The time-activity relationship was linear within the first two hours; optimal pH for esterification ranged between 5 and 6.2. There was little difference between the esterifying activity of the jejunal and ileal mucosa. Esterification of cholesterol was observed with all the investigated fatty acids but was maximal with oleic acid. Bile acids did not affect cholesterol esterase activity when present in the incubation mixture at 0.1 and 1.0 mM; the enzymatic activity, however, was significantly inhibited when bile acids were added at 20 mM. In conclusion, this study has shown that the human intestinal mucosa possesses a cholesterol esterase activity; at variance with the rat, however, the human enzyme does not seem to be stimulated by trihydroxy bile acids

  5. A Novel Glycolipid Biosurfactant Confers Grazing Resistance upon Pantoea ananatis BRT175 against the Social Amoeba Dictyostelium discoideum.

    Science.gov (United States)

    Smith, Derek D N; Nickzad, Arvin; Déziel, Eric; Stavrinides, John

    2016-01-01

    Pantoea is a versatile genus of bacteria with both plant- and animal-pathogenic strains, some of which have been suggested to cause human infections. There is, however, limited knowledge on the potential determinants used for host association and pathogenesis in animal systems. In this study, we used the model host Dictyostelium discoideum to show that isolates of Pantoea ananatis exhibit differential grazing susceptibility, with some being resistant to grazing by the amoebae. We carried out a high-throughput genetic screen of one grazing-resistant isolate, P. ananatis BRT175, using the D. discoideum pathosystem to identify genes responsible for the resistance phenotype. Among the 26 candidate genes involved in grazing resistance, we identified rhlA and rhlB, which we show are involved in the biosynthesis of a biosurfactant that enables swarming motility in P. ananatis BRT175. Using liquid chromatography-mass spectrometry (LC-MS), the biosurfactant was shown to be a glycolipid with monohexose-C10-C10 as the primary congener. We show that this novel glycolipid biosurfactant is cytotoxic to the amoebae and is capable of compromising cellular integrity, leading to cell lysis. The production of this biosurfactant may be important for bacterial survival in the environment and could contribute to the establishment of opportunistic infections. IMPORTANCE The genetic factors used for host interaction by the opportunistic human pathogen Pantoea ananatis are largely unknown. We identified two genes that are important for the production of a biosurfactant that confers grazing resistance against the social amoeba Dictyostelium discoideum. We show that the biosurfactant, which exhibits cytotoxicity toward the amoebae, is a glycolipid that incorporates a hexose rather than rhamnose. The production of this biosurfactant may confer a competitive advantage in the environment and could potentially contribute to the establishment of opportunistic infections. PMID:27303689

  6. Tissue storage and control of cholesterol metabolism in man on high cholesterol diets.

    Science.gov (United States)

    Quintão, E C; Brumer, S; Stechhahn, K

    1977-03-01

    The possibility of accumulation of tissue cholesterol in human beings submitted to high cholesterol feeding was investigated in liver biopsies and through fecal sterol balance studies. Feeding to 10 individuals 3.1 to 3.4 g/day of cholesterol for 3 weeks raised the mean serum level from 293 to 349 mg/100 ml, namely 19%, whereas the liver cholesterol content was 417 mg/100 g of wet weight. In 10 control cases eating 0.1--0.4 g/day of cholesterol serum cholesterol remained stable throughout the experimental period and the liver cholesterol content was 256 mg/100 g. Difference of liver colesterol level between the two groups was 62%. In 7 patients submitted to two periods of balance investigation on a cholesterol-free synthetic formula diet respectively prior to (PI) and after (PIII) eating the high cholesterol solid food from 4 to 15 weeks (PII), fecal steroid excretion in PIII exceeded PI in 3 patients. Such data are a direct evidence for the existence of an efficient system to release acutely stored cholesterol. In one patient bile acid excretion accounted for the difference between PIII and PI. PMID:849375

  7. Analysis of NMR spectra of sugar chains of glycolipids by 1D homonuclear Hartmann-Hahn and NOE experiments

    International Nuclear Information System (INIS)

    The authors applied 1D homonuclear Hartmann-Hahn (1D-HOHAHA) and difference NOE experiments to determine the chemical structure of Forssman's antigen, a glycolipid purified from sheep red blood cells. The subspectra corresponding to the individual sugar components were extracted from overlapping proton resonances by selective excitation of the anomeric proton resonances, so that unambiguous assignments of the sugar proton resonances were accomplished. Then, difference NOE experiments were performed to determine the linkage of the sugar units. The present procedure was found to be useful for the structure determination of glycoconjugates and also reduces the amount of samples and machine time. 8 refs.; 3 figs

  8. Decay accelerating factor (DAF) is anchored to membranes by a C-terminal glycolipid. [Decay accelerating factor

    Energy Technology Data Exchange (ETDEWEB)

    Medof, M.E.; Haas, R.; Walter, E.I.; Rosenberry, T.L.

    1986-03-01

    Purified 70 kDa membrane (m) DAF incorporates into cells when added in vitro. A 2 kDa smaller DAF form which functions extrinsically like C4bp but is unable to incorporate can be isolated from urine (u). Because of common deficits of mDAF and acetylcholinesterase (AChE) in erythrocytes (E) of patients with paroxysmal nocturnal hemoglobinuria (PNH), mDAF was analyzed for a O-terminal glycolipid membrane anchor similar to that in E AChE. Incubation of E with phosphatidylinositol-specific phospholipase C, an enzyme which cleaves a similar glycolipid anchor in trypanosome variant surface glycoproteins (mfVSGs), released 20% of the DAF antigen. The released DAF species resembled uDAF in size, extrinsic model of C4b2a decay, and lack of hydrophobicity. Reductive radiomethylation of mDAF with (/sup 14/C)HCHO and NaCNBH/sub 3/ revealed ethanolamine and glucosamine in proportions similar to those in the E AChE glycolipid anchor. Papain cleavage of radiomethylated mDAF released the labeled ethanolamine and glucosamine in small O-terminal fragments from the residual DAF that retained N-terminal Asp. Following labeling of the anchors of mDAF and E AChE with the lipophilic photoreagent 3-trifluoromethyl-3-(m-(/sup 125/I)iodophenyl)diazirine, cleavage at the glucosamine residue by deamination quantitatively released the label from both proteins. Biosynthetic labeling of Hela cells with (/sup 3/H)ethanolamine resulted in rapid /sup 3/H incorporation into both 48 kDa proDAF and 70 kDa mDAF. These data indicate that mDAF is anchored by a glycolipid similar to that in E AChE, mfVSGs and Thy-1 antigen and raise the possibility that a defect in the assembly or attachment of this structure could account for the deficits of mDAF and E AChE in PNH.

  9. Diet serum cholesterol and coronary diseases

    Directory of Open Access Journals (Sweden)

    Narindar Nath

    1961-07-01

    Full Text Available The probable sequence of events leading to atherosclerotic disease of the coronary artery and heart attack are briefly described. Blood cholesterol as a casual agent in atherosclerosis and how blood cholesterol can be modified are discussed. The effects of various dietary components particularly quality and quantity of fat and protein on the blood cholesterol concentration are discussed and it is emphasized that more work needs to be done to ascertain the role of individual components of the diet and their relative importance in atherogenesis.

  10. The role of cholesterol in membrane fusion.

    Science.gov (United States)

    Yang, Sung-Tae; Kreutzberger, Alex J B; Lee, Jinwoo; Kiessling, Volker; Tamm, Lukas K

    2016-09-01

    Cholesterol modulates the bilayer structure of biological membranes in multiple ways. It changes the fluidity, thickness, compressibility, water penetration and intrinsic curvature of lipid bilayers. In multi-component lipid mixtures, cholesterol induces phase separations, partitions selectively between different coexisting lipid phases, and causes integral membrane proteins to respond by changing conformation or redistribution in the membrane. But, which of these often overlapping properties are important for membrane fusion?-Here we review a range of recent experiments that elucidate the multiple roles that cholesterol plays in SNARE-mediated and viral envelope glycoprotein-mediated membrane fusion. PMID:27179407

  11. Lightweight cryptography for constrained devices

    DEFF Research Database (Denmark)

    Alippi, Cesare; Bogdanov, Andrey; Regazzoni, Francesco

    2014-01-01

    Lightweight cryptography is a rapidly evolving research field that responds to the request for security in resource constrained devices. This need arises from crucial pervasive IT applications, such as those based on RFID tags where cost and energy constraints drastically limit the solution...... complexity, with the consequence that traditional cryptography solutions become too costly to be implemented. In this paper, we survey design strategies and techniques suitable for implementing security primitives in constrained devices....

  12. Triglycerides, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol in rats exposed to premium motor spirit fumes

    Directory of Open Access Journals (Sweden)

    Ogbevire L Aberare

    2011-01-01

    Full Text Available Background: Deliberate and regular exposure to premium motor spirit fumes is common and could be a risk factor for liver disease in those who are occupationally exposed. A possible association between premium motor spirit fumes and plasma levels of triglyceride, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol using a rodent model could provide new insights in the pathology of diseases where cellular dysfunction is an established risk factor. Aim: The aim of this study was to evaluate the possible effect of premium motor spirit fumes on lipids and lipoproteins in workers occupationally exposed to premium motor spirit fumes using rodent model. Materials and Methods: Twenty-five Wister albino rats (of both sexes were used for this study between the 4 th of August and 7 th of September, 2010. The rats were divided into five groups of five rats each. Group 1 rats were not exposed to premium motor spirit fumes (control group, group 2 rats were exposed for 1 hour daily, group 3 for 3 hours daily, group 4 for 5 hours daily and group 5 for 7 hours daily. The experiment lasted for a period of 4 weeks. Blood samples obtained from all the groups after 4 weeks of exposure were used for the estimation of plasma levels of triglyceride, total cholesterol, high density lipoprotein- cholesterol and low density lipoprotein- cholesterol. Result: Results showed significant increase in means of plasma total cholesterol and low density lipoprotein levels (P<0.05. The mean triglyceride and total body weight were significantly lower (P<0.05 in the exposed group when compared with the unexposed. The plasma level of high density lipoprotein, the ratio of low density lipoprotein to high density lipoprotein and the ratio of total cholesterol to high density lipoprotein did not differ significantly in exposed subjects when compared with the control group. Conclusion: These results showed that frequent exposure to petrol fumes

  13. HDL: More Than Just Cholesterol

    Directory of Open Access Journals (Sweden)

    Anna Meilina

    2010-12-01

    Full Text Available BACKGROUND: Plasma concentration of high density lipoprotein cholesterol (HDL-C are strongly, consistenly, and independently inversely associated with risk of atheroschlerotic cardiovascular disease (CVD. However, the last decade has seen several observations that do not follow this simple script. CONTENT: A proteomic analysis of HDL has given us an intriguing glimpse into novel components of HDL. HDL isolated from normal humans contains several classes of proteins, including not only apolipoproteins, but also complement regulatory proteins, endopeptidase inhibitors, hemopexin, and acute phase response proteins. These observations raise the possibility of unsuspected roles for HDL. HDL delivery of complement proteins would implicate HDL in innate immunity. Serine proteinase inhibitors would enable HDL to modulate proteolysis of the vessel wall. HDL from patients with coronary artery disease was enriched in apoE, apoC-IV, apoA-IV, Paraoxonase (PON, and complement factor C3. Highlighted additional mechanisms through which HDL protects the vessel wall are: HDL improves vascular function, decreases vascular inflammation, detoxifies radicals, and limits thrombosis. SUMMARY: Both inter- and intra-organ desynchrony may be involved in the pathogenesis of cardiometabolic disease attributable to effects in brain and multiple metabolic tissues including heart, liver, fat, muscle, pancreas, and gut. Efforts to dissect the molecular mediators that coordinate circadian, metabolic, and cardiovascular systems may ultimately lead to both improved therapeutics and preventive interventions. KEYWORDS: HDL, Apo–A1, RCT, inflammation, HDL dysfunction, HDL proteome, HDL & Apo-A1 mimetics.

  14. What Do My Cholesterol Levels Mean?

    Science.gov (United States)

    ... goes beyond cholesterol levels alone and considers overall risk assessment and reduction. It's still important to know your numbers, but work with your healthcare provider to treat your risk. What numbers do ...

  15. How to Get Your Cholesterol Tested

    Science.gov (United States)

    ... six years as part of a cardiovascular risk assessment. You may need to have your cholesterol and other risk factors assessed more often if your risk is elevated. Your healthcare provider will talk with you about what your ...

  16. Cholesterol oxidation products and their biological importance.

    Science.gov (United States)

    Kulig, Waldemar; Cwiklik, Lukasz; Jurkiewicz, Piotr; Rog, Tomasz; Vattulainen, Ilpo

    2016-09-01

    The main biological cause of oxysterols is the oxidation of cholesterol. They differ from cholesterol by the presence of additional polar groups that are typically hydroxyl, keto, hydroperoxy, epoxy, or carboxyl moieties. Under typical conditions, oxysterol concentration is maintained at a very low and precisely regulated level, with an excess of cholesterol. Like cholesterol, many oxysterols are hydrophobic and hence confined to cell membranes. However, small chemical differences between the sterols can significantly affect how they interact with other membrane components, and this in turn can have a substantial effect on membrane properties. In this spirit, this review describes the biological importance and the roles of oxysterols in the human body. We focus primarily on the effect of oxysterols on lipid membranes, but we also consider other issues such as enzymatic and nonenzymatic synthesis processes of oxysterols as well as pathological conditions induced by oxysterols. PMID:26956952

  17. Structure of cholesterol/ceramide monolayer mixtures

    DEFF Research Database (Denmark)

    Scheffer, L.; Solomonov, I.; Weygand, M.J.;

    2005-01-01

    The structure of monolayers of cholesterol/ ceramide mixtures was investigated using grazing incidence x-ray diffraction, immunofluorescence, and atomic force microscopy techniques. Grazing incidence x-ray diffraction measurements showed the existence of a crystalline mixed phase of the two...... components within a range of compositions of cholesterol/ ceramide between 100: 0 and 67: 33. The mixed phase coexists with the ceramide crystalline phase in the range of compositions between 50: 50 and 30: 70; between 30: 70 and 0: 100 only the highly crystalline phase of ceramide was detected. The latter...... was determined and modeled. Immunolabeling was performed with an antibody specific to the cholesterol monohydrate crystalline arrangement. The antibody recognizes crystalline cholesterol monolayers, but does not interact with crystalline ceramide. Immunofluorescence and atomic force microscopy data...

  18. Evaluation of LDL-Cholesterol / HDL-Cholesterol Ratio as Predictor of Dyslipidemia in Subclinical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Smita S. Kottagi

    2014-01-01

    Full Text Available Background: Subclinical hypothyroidism is defined as a serum TSH concentration above the upper limit of the reference range when serum T3 and T4 concentrations are within reference ranges. Subclinical thyroid disease is a laboratory diagnosis. Patients with subclinical disease have few or no definitive clinical signs or symptoms of thyroid dysfunction. It has been associated with higher levels of some cardiovascular risk factors. Despite some conflicting results, many studies have found that subjects with subclinical hypothyroidism have total cholesterol and low density lipoprotein cholesterol levels higher than euthyroid subjects. The association between subclinical hypothyroidism and dyslipidemia is well known. Aims and Objectives: This study is an attempt to find the importance of Low Density Lipoprotein – Cholesterol / Higher Density Lipoprotein - Cholesterol (LDL-C/HDL-C ratio rather than measurement of individual lipid profile parameters in bringing to light the dyslipidemic state associated with subclinical hypothyroidism. Materials and Methods: We studied 30 subclinical hypothyroid cases with age above 35 yrs and 30 age matched euthyroid controls. Serum T3, T4, TSH were estimated by ELISA method, serum total cholesterol, HDL Cholesterol by enzymatic CHOD-PAP method, and LDL cholesterol using Friedewald formula. Results: We found the significant increase in the serum levels of TSH (p < 0.001, Total cholesterol (p<0.001, LDL cholesterol (p<0.001, and LDL-C/HDL-C (p<0.001, Systolic blood pressure and diastolic blood pressure (p<0.001. There was no significant change in the levels of serum T3, T4, HDL- cholesterol. Conclusion: Increased levels of total cholesterol, LDL cholesterol and increased LDL-C/HDL-C ratio are seen in patients with subclinical hypothyroidism. LDL-C/HDLC ratio is a better indicator for dyslipidemia in subclinical hypothyroid cases.

  19. From blood to gut: Direct secretion of cholesterol via transintestinal cholesterol efflux

    Institute of Scientific and Technical Information of China (English)

    Carlos; LJ; Vrins

    2010-01-01

    The reverse cholesterol transport pathway (RCT) is the focus of many cholesterol-lowering therapies. By way of this pathway, excess cholesterol is collected from peripheral tissues and delivered back to the liver and gastrointestinal tract for excretion from the body. For a long time this removal via the hepatobiliary secretion was considered to be the sole route involved in the RCT. However, observations from early studies in animals and humans already pointed towards the possibility of another route. In t...

  20. A new framework for reverse cholesterol transport: Non-biliary contributions to reverse cholesterol transport

    Institute of Scientific and Technical Information of China (English)

    Ryan; E; Temel; J; Mark; Brown

    2010-01-01

    Reduction of low-density lipoprotein-cholesterol through statin therapy has only modestly decreased coronary heart disease (CHD)-associated mortality in developed countries, which has prompted the search for alternative therapeutic strategies for CHD. Major efforts are now focused on therapies that augment high-density lipoprotein (HDL)-mediated reverse cholesterol transport (RCT), and ultimately increase the fecal disposal of cholesterol. The process of RCT has long been thought to simply involve HDL-media...

  1. Dietary Phospholipids and Intestinal Cholesterol Absorption

    OpenAIRE

    Sally Tandy; Chung, Rosanna W. S.; Elaine Wat; Alvin Kamili; Cohn, Jeffrey S.

    2010-01-01

    Experiments carried out with cultured cells and in experimental animals have consistently shown that phospholipids (PLs) can inhibit intestinal cholesterol absorption. Limited evidence from clinical studies suggests that dietary PL supplementation has a similar effect in man. A number of biological mechanisms have been proposed in order to explain how PL in the gut lumen is able to affect cholesterol uptake by the gut mucosa. Further research is however required to establish whether the abili...

  2. Statin-induced chronic cholesterol depletion inhibits Leishmania donovani infection: Relevance of optimum host membrane cholesterol.

    Science.gov (United States)

    Kumar, G Aditya; Roy, Saptarshi; Jafurulla, Md; Mandal, Chitra; Chattopadhyay, Amitabha

    2016-09-01

    Leishmania are obligate intracellular protozoan parasites that invade and survive within host macrophages leading to leishmaniasis, a major cause of mortality and morbidity worldwide, particularly among economically weaker sections in tropical and subtropical regions. Visceral leishmaniasis is a potent disease caused by Leishmania donovani. The detailed mechanism of internalization of Leishmania is poorly understood. A basic step in the entry of Leishmania involves interaction of the parasite with the host plasma membrane. In this work, we have explored the effect of chronic metabolic cholesterol depletion using lovastatin on the entry and survival of Leishmania donovani in host macrophages. We show here that chronic cholesterol depletion of host macrophages results in reduction in the attachment of Leishmania promastigotes, along with a concomitant reduction in the intracellular amastigote load. These results assume further relevance since chronic cholesterol depletion is believed to mimic physiological cholesterol modulation. Interestingly, the reduction in the ability of Leishmania to enter host macrophages could be reversed upon metabolic replenishment of cholesterol. Importantly, enrichment of host membrane cholesterol resulted in reduction in the entry and survival of Leishmania in host macrophages. As a control, the binding of Escherichia coli to host macrophages remained invariant under these conditions, thereby implying specificity of cholesterol requirement for effective leishmanial infection. To the best of our knowledge, these results constitute the first comprehensive demonstration that an optimum content of host membrane cholesterol is necessary for leishmanial infection. Our results assume relevance in the context of developing novel therapeutic strategies targeting cholesterol-mediated leishmanial infection. PMID:27319380

  3. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid-based molecular thermometers

    Science.gov (United States)

    Bauersachs, T.; Rochelmeier, J.; Schwark, L.

    2015-06-01

    It has been demonstrated that the relative distribution of heterocyst glycolipids (HGs) in cultures of N2-fixing heterocystous cyanobacteria is largely controlled by growth temperature, suggesting a potential use of these components in paleoenvironmental studies. Here, we investigated the effect of environmental parameters (e.g., surface water temperatures, oxygen concentrations and pH) on the distribution of HGs in a natural system using water column filtrates collected from Lake Schreventeich (Kiel, Germany) from late July to the end of October 2013. HPLC-ESI/MS (high-performance liquid chromatography coupled to electrospray ionization-mass spectrometry) analysis revealed a dominance of 1-(O-hexose)-3,25-hexacosanediols (HG26 diols) and 1-(O-hexose)-3-keto-25-hexacosanol (HG26 keto-ol) in the solvent-extracted water column filtrates, which were accompanied by minor abundances of 1-(O-hexose)-3,27-octacosanediol (HG28 diol) and 1-(O-hexose)-3-keto-27-octacosanol (HG28 keto-ol) as well as 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol) and 1-(O-hexose)-3-keto-25,27-octacosanediol (HG28 keto-diol). Fractional abundances of alcoholic and ketonic HGs generally showed strong linear correlations with surface water temperatures and no or only weak linear correlations with both oxygen concentrations and pH. Changes in the distribution of the most abundant diol and keto-ol (e.g., HG26 diol and HG26 keto-ol) were quantitatively expressed as the HDI26 (heterocyst diol index of 26 carbon atoms) with values of this index ranging from 0.89 in mid-August to 0.66 in mid-October. An average HDI26 value of 0.79, which translates into a calculated surface water temperature of 15.8 ± 0.3 °C, was obtained from surface sediments collected from Lake Schreventeich. This temperature - and temperatures obtained from other HG indices (e.g., HDI28 and HTI28) - is similar to the one measured during maximum cyanobacterial productivity in early to mid-September and suggests that HGs

  4. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid based molecular thermometers

    Science.gov (United States)

    Bauersachs, T.; Rochelmeier, J.; Schwark, L.

    2015-01-01

    It has been demonstrated that the relative distribution of heterocyst glycolipids (HGs) in cultures of N2-fixing heterocystous cyanobacteria is largely controlled by growth temperature, suggesting a potential use of these components in paleoenvironmental studies. Here, we investigated the effect of environmental parameters (e.g. surface water temperatures, oxygen concentrations and pH) on the distribution of HGs in a natural system using water column filtrates collected from Lake Schreventeich (Kiel, Germany) from late July to the end of October 2013. HPLC-ESI/MS analysis revealed a dominance of 1-(O-hexose)-3,25-hexacosanediols (HG26 diols) and 1-(O-hexose)-3-keto-25-hexacosanol (HG26 keto-ol) in the solvent extracted water column filtrates, which were accompanied by minor abundances of 1-(O-hexose)-3,27-octacosanediol (HG28 diol) and 1-(O-hexose)-3-keto-27-octacosanol (HG28 keto-ol) as well as 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol) and 1-(O-hexose)-3-keto-25,27-octacosanediol (HG28 keto-diol). Fractional abundances of alcoholic and ketonic HGs generally showed strong linear correlations with surface water temperatures and no or only weak linear correlations with both oxygen concentrations and pH. Changes in the distribution of the most abundant diol and keto-ol (e.g., HG26 diol and HG26 keto-ol) were quantitatively expressed as the HDI26 (heterocyst diol index of 26carbon atoms) with values of this index ranging from 0.89 in mid-August to 0.66 in mid-October. An average HDI26 value of 0.79, which translates into a calculated surface water temperature of 15.8 ± 0.3 °C, was obtained from surface sediments collected from Lake Schreventeich. This temperature - and temperatures obtained from other HG indices (e.g., HDI28 and HTI28) - is similar to the one measured during maximum cyanobacterial productivity in early to mid-September and suggests that HGs preserved in Lake Schreventeich sediments record summer surface water temperatures. As N2-fixing

  5. Cholesterol content in meat of some Cyprinidae

    Directory of Open Access Journals (Sweden)

    Živković Dragić L.

    2002-01-01

    Full Text Available The aim of this paper was to examine cholesterol content in meat of five Cyprinidae species: white bream (Bllica bjoerkna L, carp bream (Abramis brama L, baltic vimba (Vimba vimba carinata Pallas, zope (Abramis balerus L and crucian carp (Carassius carassius gibelio Bloch from the river Danube. Cholesterol content was examined in the function of season factor and individual weight. Cholesterol concentration in meat of white bream carp bream, baltic vimba, zope and crucian carp is on average level below 20 mg/100 g of meat, which makes meat of these fish species nutritively very valuable. Cholesterol content is variable during the season. Its concentration in meat and in lipids is lowest during spring, during summer it increases and during autumn decreases, except in meat of white bream. Body weight has influence on cholesterol content when its concentration is expressed as % of cholesterol in lipids. Its content in lipids decreases with increasing of individual weight, except in meat of carp bream.

  6. CHOLESTEROL ASSIMILATION BY COMMERCIAL YOGHURT STARTER CULTURES

    Directory of Open Access Journals (Sweden)

    Małgorzata Ziarno

    2007-03-01

    Full Text Available The ability to in vitro cholesterol level reduction in laboratory media has been shown for numerous strains of lactic acid bacteria, but not for all strains of lactic bacteria used in the dairy industry. The aim of this work was the determination of the ability of selected thermophilic lactic acid bacteria to cholesterol assimilation during 24 h culture in MRS broth. Commercial starter cultures showed various ability to cholesterol assimilation from laboratory medium. In case of starter cultures used for production of traditional yoghurt, consisting of Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, the quantity of assimilated cholesterol did not exceed 27% of its initial contents (0.7 g in 1 dm3. Starter cultures used for bioyoghurt production, containing also probiotic strains (came from Lactobacillus acidophilus species or Bifidobacterium genus assimilated from almost 18% to over 38% of cholesterol. For one monoculture of Lb. acidophilus, cholesterol assimilation ability of 49-55% was observed, despite that the number of bacterial cells in this culture was not different from number of bacteria in other cultures.

  7. Cholesterol suppresses antimicrobial effect of statins

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Haeri

    2015-12-01

    Full Text Available Objective(s:Isoprenoid biosynthesis is a key metabolic pathway to produce a wide variety of biomolecules such as cholesterol and carotenoids, which target cell membranes. On the other hand, it has been reported that statins known as inhibitors of isoprenoid biosynthesis and cholesterol lowering agents, may have a direct antimicrobial effect on the some bacteria. The exact action of statins in microbial metabolism is not clearly understood. It is possible that statins inhibit synthesis or utilization of some sterol precursor necessary for bacterial membrane integrity. Accordingly, this study was designed in order to examine if statins inhibit the production of a compound, which can be used in the membrane, and whether cholesterol would replace it and rescue bacteria from toxic effects of statins. Materials and Methods: To examine the possibility we assessed antibacterial effect of statins with different classes; lovastatin, simvastatin, and atorvastatin, alone and in combination with cholesterol on two Gram-positive (Staphylococcus aureus and Enterococcus faecalis and two Gram-negative (Pseudomonas aeruginosa and Escherichia coli bacteria using gel diffusion assay. Results: Our results showed that all of the statins except for lovastatin had significant antibacterial property in S. aureus, E. coli, and Enter. faecalis. Surprisingly, cholesterol nullified the antimicrobial action of effective statins in statin-sensitive bacteria. Conclusion: It is concluded that statins may deprive bacteria from a metabolite responsible for membrane stability, which is effectively substituted by cholesterol.

  8. Dietary cholesterol modulates pathogen blocking by Wolbachia.

    Directory of Open Access Journals (Sweden)

    Eric P Caragata

    Full Text Available The bacterial endosymbiont Wolbachia pipientis protects its hosts from a range of pathogens by limiting their ability to form infections inside the insect. This "pathogen blocking" could be explained by innate immune priming by the symbiont, competition for host-derived resources between pathogens and Wolbachia, or the direct modification of the cell or cellular environment by Wolbachia. Recent comparative work in Drosophila and the mosquito Aedes aegypti has shown that an immune response is not required for pathogen blocking, implying that there must be an additional component to the mechanism. Here we have examined the involvement of cholesterol in pathogen blocking using a system of dietary manipulation in Drosophila melanogaster in combination with challenge by Drosophila C virus (DCV, a common fly pathogen. We observed that flies reared on cholesterol-enriched diets infected with the Wolbachia strains wMelPop and wMelCS exhibited reduced pathogen blocking, with viral-induced mortality occurring 2-5 days earlier than flies reared on Standard diet. This shift toward greater virulence in the presence of cholesterol also corresponded to higher viral copy numbers in the host. Interestingly, an increase in dietary cholesterol did not have an effect on Wolbachia density except in one case, but this did not directly affect the strength of pathogen blocking. Our results indicate that host cholesterol levels are involved with the ability of Wolbachia-infected flies to resist DCV infections, suggesting that cholesterol contributes to the underlying mechanism of pathogen blocking.

  9. Antibody to endotoxin core glycolipid reverses reticuloendothelial system depression in an animal model of severe sepsis and surgical injury

    International Nuclear Information System (INIS)

    To study the effect of severe sepsis on the function of the reticuloendothelial system (RES) we have measured the clearance kinetics and organ distribution of both low-dose technetium tin colloid (TTC) and 75selenomethionine-labelled E. coli in rabbits 24 hours after either sham laparotomy or appendix devascularization. Sepsis resulted in similar delayed blood clearance and reduced liver (Kupffer cell) uptake of both TTC and E. coli. To investigate the ability of polyclonal antibody to E. coli-J-5 (core glycolipid) to improve RES function in the same model of sepsis, further animals were pretreated with either core glycolipid antibody or control serum (10 ml IV) 2 hours before induction of sepsis. TTC clearance kinetics were determined 24 hours later. Antibody pretreated animals showed: a reduced incidence of bacteremia; normalization of the rate of blood clearance and liver uptake of TTC; and a 'rebound' increase in splenic uptake of TTC. We conclude that antibody to E. coli-J-5 enhances bacterial clearance by the RES

  10. Isolation of Pseudozyma churashimaensis sp. nov., a novel ustilaginomycetous yeast species as a producer of glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Ogura, Yuki; Takashima, Masako; Hirose, Naoto; Fukuoka, Tokuma; Imura, Tomohiro; Kondo, Yukishige; Kitamoto, Dai

    2011-08-01

    An ustilaginomycetous anamorphic yeast species isolated from the leaves of Saccharum officinarum (sugarcane) in Okinawa, Japan, was identified as a novel Pseudozyma species based on morphological and physiological aspects and molecular taxonomic analysis using the D1/D2 domains of the large subunit (26S) rRNA gene and the internal transcribed spacer 1 (ITS1)-5.8S-ITS2 regions. The name Pseudozyma churashimaensis sp. nov. was proposed for the novel species, with JCM 16988(T) as the type strain. Interestingly, P. churashimaensis was found to produce glycolipid biosurfactants, a mixture of mannosylerythritol lipids (MELs), including a novel tri-acetylated derivative (MEL-A2), from glucose. The observed critical micelle concentration (CMC) and the surface tension at CMC of MEL-A2 were 1.7 × 10⁻⁶ M and 29.2 mN/m, respectively. Moreover, on a water-penetration scan, MEL-A2 efficiently formed different lyotropic liquid crystalline phases, including the lamella phase at a wide range of concentrations, indicating its excellent surface-active and self-assembling properties. The novel strain of the genus Pseudozyma should thus facilitate the application of glycolipid biosurfactants in combination with other MEL producers. PMID:21606002

  11. Dairy products and plasma cholesterol levels

    Directory of Open Access Journals (Sweden)

    Lena Ohlsson

    2010-08-01

    Full Text Available Cholesterol synthesized in the body or ingested is an essential lipid component for human survival from our earliest life. Newborns ingest about 3–4 times the amount per body weight through mother's milk compared to the dietary intake of adults. A birth level of 1.7 mmol/L plasma total cholesterol will increase to 4–4.5 mmol/L during the nursing period and continue to increase from adulthood around 40% throughout life. Coronary artery disease and other metabolic disorders are strongly associated with low-density lipoprotein (LDL and high-density lipoprotein (HDL cholesterol as well as triacylglycerol concentration. Milk fat contains a broad range of fatty acids and some have a negative impact on the cholesterol rich lipoproteins. The saturated fatty acids (SFAs, such as palmitic acid (C16:0, myristic acid (C14:0, and lauric acid (C12:0, increase total plasma cholesterol, especially LDL, and constitute 11.3 g/L of bovine milk, which is 44.8% of total fatty acid in milk fat. Replacement of dairy SFA and trans-fatty acids with polyunsaturated fatty acids decreases plasma cholesterol, especially LDL cholesterol, and is associated with a reduced risk of cardiovascular disease. Available data shows different effects on lipoproteins for different dairy products and there is uncertainty as to the impact a reasonable intake amount of dairy items has on cardiovascular risk. The aim of this review is to elucidate the effect of milk components and dairy products on total cholesterol, LDL, HDL, and the LDL/HDL quotients. Based on eight recent randomized controlled trials of parallel or cross-over design and recent reviews it can be concluded that replacement of saturated fat mainly (but not exclusively derived from high-fat dairy products with low-fat dairy products lowers LDL/HDL cholesterol and total/HDL cholesterol ratios. Whey, dairy fractions enriched in polar lipids, and techniques such as fermentation, or fortification of cows feeding can be used

  12. Chromatographic separation of cholesterol in foods.

    Science.gov (United States)

    Fenton, M

    1992-10-30

    Based on the current literature and on experience gained in the laboratory, a simplified procedure using direct saponification (0.4 M potassium hydroxide in ethanol and heating at 60 degrees C for 1 h) is the most appropriate method for the determination of total cholesterol in foods. Extraction of the unsaponifiable matter with hexane is efficient and no extra clean-up is required before quantification. An internal standard, 5 alpha-cholestane or epicoprostanol, should be added to the sample prior to saponification and, together with reference standards, carried through the entire procedure to ensure accurate results. A significant improvement in cholesterol methodology has been achieved by decreasing the sample size and performing all the sample preparation steps in a single tube. The method has the advantages of elimination of an initial solvent extraction for total lipids and errors resulting from multiple extractions, transfers, filtration and wash steps after saponification. The resulting hexane extract, which contains a variety of sterols and fat soluble vitamins, requires an efficient capillary column for complete resolution of cholesterol from the other compounds present. The development of fused-silica capillary columns using cross-linked and bonded liquid phases has provided high thermal stability, inertness and separation efficiency and, together with automated cold on-column gas chromatographic injection systems, has resulted in reproducible cholesterol determinations in either underivatized or derivatized form. If free cholesterol and its esters need to be determined separately, they are initially extracted with other lipids with chloroform-methanol followed by their separation by column or thin-layer chromatography and subsequently analysed by gas or liquid chromatography. Although capillary gas chromatography offers superior efficiency in separation, the inherent benefits of liquid chromatography makes it a potential alternative. Isotope dilution

  13. Taurine ameliorates cholesterol metabolism by stimulating bile acid production in high-cholesterol-fed rats.

    Science.gov (United States)

    Murakami, Shigeru; Fujita, Michiko; Nakamura, Masakazu; Sakono, Masanobu; Nishizono, Shoko; Sato, Masao; Imaizumi, Katsumi; Mori, Mari; Fukuda, Nobuhiro

    2016-03-01

    This study was designed to investigate the effects of dietary taurine on cholesterol metabolism in high-cholesterol-fed rats. Male Sprague-Dawley rats were randomly divided into two dietary groups (n = 6 in each group): a high-cholesterol diet containing 0.5% cholesterol and 0.15% sodium cholate, and a high-cholesterol diet with 5% (w/w) taurine. The experimental diets were given for 2 weeks. Taurine supplementation reduced the serum and hepatic cholesterol levels by 37% and 32%, respectively. Faecal excretion of bile acids was significantly increased in taurine-treated rats, compared with untreated rats. Biliary bile acid concentrations were also increased by taurine. Taurine supplementation increased taurine-conjugated bile acids by 61% and decreased glycine-conjugated bile acids by 53%, resulting in a significant decrease in the glycine/taurine (G/T) ratio. Among the taurine-conjugated bile acids, cholic acid and deoxycholic acid were significantly increased. In the liver, taurine supplementation increased the mRNA expression and enzymatic activity of hepatic cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme for bile acid synthesis, by three- and two-fold, respectively. Taurine also decreased the enzymatic activity of acyl-CoA:cholesterol acyltransferase (ACAT) and microsomal triglyceride transfer protein (MTP). These observations suggest that taurine supplementation increases the synthesis and excretion of taurine-conjugated bile acids and stimulates the catabolism of cholesterol to bile acid by elevating the expression and activity of CYP7A1. This may reduce cholesterol esterification and lipoprotein assembly for very low density lipoprotein (VLDL) secretion, leading to reductions in the serum and hepatic cholesterol levels. PMID:26710098

  14. Numerical PDE-constrained optimization

    CERN Document Server

    De los Reyes, Juan Carlos

    2015-01-01

    This book introduces, in an accessible way, the basic elements of Numerical PDE-Constrained Optimization, from the derivation of optimality conditions to the design of solution algorithms. Numerical optimization methods in function-spaces and their application to PDE-constrained problems are carefully presented. The developed results are illustrated with several examples, including linear and nonlinear ones. In addition, MATLAB codes, for representative problems, are included. Furthermore, recent results in the emerging field of nonsmooth numerical PDE constrained optimization are also covered. The book provides an overview on the derivation of optimality conditions and on some solution algorithms for problems involving bound constraints, state-constraints, sparse cost functionals and variational inequality constraints.

  15. Cholesterol efflux analyses using stable isotopes and mass spectrometry

    OpenAIRE

    Robert J Brown; Shao, Fei; Baldán, Ángel; Albert, Carolyn J.; Ford, David A.

    2012-01-01

    Cholesterol efflux from macrophages and the vascular wall is the initial step of the cardiovascular protective reverse cholesterol transport process. This study demonstrates a mass spectrometry based assay to measure the cellular and media content of [d7]-cholesterol and unlabeled cholesterol that can be used to measure cholesterol efflux from cell lines. Using a triple quadrupole ESI-MS instrument in direct infusion mode, product ion scanning for m/z 83, neutral loss (NL) 375.5 scanning and ...

  16. Cholesterol and ocular pathologies: focus on the role of cholesterol-24S-hydroxylase in cholesterol homeostasis

    Directory of Open Access Journals (Sweden)

    Fourgeux Cynthia

    2015-03-01

    Full Text Available The retina is responsible for coding the light stimulus into a nervous signal that is transferred to the brain via the optic nerve. The retina is formed by the association of the neurosensory retina and the retinal pigment epithelium that is supported by Bruch’s membrane. Both the physical and metabolic associations between these partners are crucial for the functioning of the retina, by means of nutrient intake and removal of the cell and metabolic debris from the retina. Dysequilibrium are involved in the aging processes and pathologies such as age-related macular degeneration, the leading cause of visual loss after the age of 50 years in Western countries. The retina is composed of several populations of cells including glia that is involved in cholesterol biosynthesis. Cholesterol is the main sterol in the retina. It is present as free form in cells and as esters in Bruch’s membrane. Accumulation of cholesteryl esters has been associated with aging of the retina and impairment of the retinal function. Under dietary influence and in situ synthesized, the metabolism of cholesterol is regulated by cell interactions, including neurons and glia via cholesterol-24S-hydroxylase. Several pathophysiological associations with cholesterol and its metabolism can be suggested, especially in relation to glaucoma and age-related macular degeneration.

  17. Emerging roles of the intestine in control of cholesterol metabolism

    Institute of Scientific and Technical Information of China (English)

    Janine K Kruit; Albert K Groen; Theo J van Berkel; Folkert Kuipers

    2006-01-01

    The liver is considered the major "control center" for maintenance of whole body cholesterol homeostasis. This organ is the main site for de novo cholesterol synthesis,clears cholesterol-containing chylomicron remnants and low density lipoprotein particles from plasma and is the major contributor to high density lipoprotein (HDL; good cholesterol) formation. The liver has a central position in the classical definition of the reverse cholesterol transport pathway by taking up peripheryderived cholesterol from lipoprotein particles followed by conversion into bile acids or its direct secretion into bile for eventual removal via the feces. During the past couple of years, however, an additional important role of the intestine in maintenance of cholesterol homeostasis and regulation of plasma cholesterol levels has become apparent. Firstly, molecular mechanisms of cholesterol absorption have been elucidated and novel pharmacological compounds have been identified that interfere with the process and positively impact plasma cholesterol levels. Secondly, it is now evident that the intestine itself contributes to fecal neutral sterol loss as a cholesterol-secreting organ. Finally, very recent work has unequivocally demonstrated that the intestine contributes significantly to plasma HDL cholesterol levels.Thus, the intestine is a potential target for novel antiatherosclerotic treatment strategies that, in addition to interference with cholesterol absorption, modulate direct cholesterol excretion and plasma HDL cholesterol levels.

  18. A novel alkyne cholesterol to trace cellular cholesterol metabolism and localization.

    Science.gov (United States)

    Hofmann, Kristina; Thiele, Christoph; Schött, Hans-Frieder; Gaebler, Anne; Schoene, Mario; Kiver, Yuriy; Friedrichs, Silvia; Lütjohann, Dieter; Kuerschner, Lars

    2014-03-01

    Cholesterol is an important lipid of mammalian cells and plays a fundamental role in many biological processes. Its concentration in the various cellular membranes differs and is tightly regulated. Here, we present a novel alkyne cholesterol analog suitable for tracing both cholesterol metabolism and localization. This probe can be detected by click chemistry employing various reporter azides. Alkyne cholesterol is accepted by cellular enzymes from different biological species (Brevibacterium, yeast, rat, human) and these enzymes include cholesterol oxidases, hydroxylases, and acyl transferases that generate the expected metabolites in in vitro and in vivo assays. Using fluorescence microscopy, we studied the distribution of cholesterol at subcellular resolution, detecting the lipid in the Golgi and at the plasma membrane, but also in the endoplasmic reticulum and mitochondria. In summary, alkyne cholesterol represents a versatile, sensitive, and easy-to-use tool for tracking cellular cholesterol metabolism and localization as it allows for manifold detection methods including mass spectrometry, thin-layer chromatography/fluorography, and fluorescence microscopy. PMID:24334219

  19. Hyperreactive malarial splenomegaly is associated with low levels of antibodies against red blood cell and Plasmodium falciparum derived glycolipids in Yanomami Amerindians from Venezuela.

    Science.gov (United States)

    Vivas, Livia; O'Dea, Kieran P; Noya, Oscar; Pabon, Rosalba; Magris, Magda; Botto, Carlos; Holder, Anthony A; Brown, K Neil

    2008-03-01

    The immunological basis of the aberrant immune response in hyperreactive malarial splenomegaly (HMS) is poorly understood, but believed to be associated with polyclonal B cell activation by an unidentified malaria mitogen, leading to unregulated immunoglobulin and autoantibody production. HMS has been previously reported in Yanomami communities in the Upper Orinoco region of the Venezuelan Amazon. To investigate a possible association between antibody responses against Plasmodium falciparum and uninfected red blood cell (URBC) glycolipids and splenomegaly, a direct comparison of the parasite versus host anti-glycolipid antibody responses was made in an isolated community of this area. The anti-P. falciparum glycolipid (Pfglp) response was IgG3 dominated, whereas the uninfected red blood cell glycolipid (URBCglp) response showed a predominance of IgG1. The levels of IgG1 against Pfglp, and of IgG4 and IgM against URBCglp were significantly higher in women, while the anti-Pfglp or URBCglp IgM levels were inversely correlated with the degree of splenomegaly. Overall, these results suggest differential regulation of anti-parasite and autoreactive responses and that these responses may be linked to the development and evolution of HMS in this population exposed to endemic malaria. The high mortality rates associated with HMS point out that its early diagnosis together with the implementation of malaria control measures in these isolated Amerindian communities are a priority. PMID:18243148

  20. Toxin a from Clostridium difficile binds to rabbit erythrocyte glycolipids with therminal Gal. cap alpha. 1-3Gal. beta. 1-4GlcNaC sequences

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.F.; Krivan, H.; Wilkins, T.; Smith, D.F.

    1987-05-01

    Toxin A is one of two clostridial toxins implicated as the causative agent of pseudomembranous colitis in patients undergoing postoperative antibiotic therapy. Evidence that the carbohydrate binding determinant for this toxin is a glycoconjugate(s) with non-reducing Gal..cap alpha..1-3Gal..beta..1-4GlcNAc has recently been reported. Specific agglutination of rabbit erythrocytes by Toxin A is inhibited by bovine thyroglobulin and prevented by pretreatment of cells with ..cap alpha..-galactosidase. Total lipid extracts from rabbit erythrocytes were subjected to thin layer chromatography and the chromatogram overlaid with purified /sup 125/I-labeled Toxin A. Two major and several minor toxin-binding glycolipids were detected following autoradiography. The major toxin-binding glycolipids were identified as pentasaccharide- and decasaccharide-ceramides expressing terminal Gal..cap alpha..1-3Gal..beta..1-4GlcNAc sequences. Treatment of the toxin-binding glycolipids with ..cap alpha..-galactosidase abolished binding. Forsmann glycolipid, globoside, Gal..cap alpha..1-4 Gal..beta..1-4Glc-cer, and Gal..cap alpha..1-3Gal..beta..1-4Glc-cer did not bind the toxin. These observations are consistent with the proposed carbohydrate specificity of the toxin for the non-reducing terminal sequence, Gal..cap alpha..1-3Gal..beta..1-4GlcNAc.

  1. Increased plasma membrane cholesterol in cystic fibrosis cells correlates with CFTR genotype and depends on de novo cholesterol synthesis

    OpenAIRE

    Sonawane Nitin D; Previs Stephen F; Jiang Dechen; Ruddy Jennifer; Manson Mary E; West Richard H; Fang Danjun; Burgess James D; Kelley Thomas J

    2010-01-01

    Abstract Background Previous observations demonstrate that Cftr-null cells and tissues exhibit alterations in cholesterol processing including perinuclear cholesterol accumulation, increased de novo synthesis, and an increase in plasma membrane cholesterol accessibility compared to wild type controls. The hypothesis of this study is that membrane cholesterol accessibility correlates with CFTR genotype and is in part influenced by de novo cholesterol synthesis. Methods Electrochemical detectio...

  2. Elevated Remnant Cholesterol Causes Both Low-Grade Inflammation and Ischemic Heart Disease, Whereas Elevated Low-Density Lipoprotein Cholesterol Causes Ischemic Heart Disease Without Inflammation

    DEFF Research Database (Denmark)

    Varbo, Anette; Tybjærg-Hansen, Anne; Nordestgaard, Børge G;

    2013-01-01

    Elevated nonfasting remnant cholesterol and low-density lipoprotein (LDL) cholesterol are causally associated with ischemic heart disease (IHD), but whether elevated nonfasting remnant cholesterol and LDL cholesterol both cause low-grade inflammation is currently unknown....

  3. Lipoproteins, cholesterol homeostasis and cardiac health

    Directory of Open Access Journals (Sweden)

    Tyler F. Daniels, Karen M. Killinger, Jennifer J. Michal, Raymond W. Wright Jr., Zhihua Jiang

    2009-01-01

    Full Text Available Cholesterol is an essential substance involved in many functions, such as maintaining cell membranes, manufacturing vitamin D on surface of the skin, producing hormones, and possibly helping cell connections in the brain. When cholesterol levels rise in the blood, they can, however, have dangerous consequences. In particular, cholesterol has generated considerable notoriety for its causative role in atherosclerosis, the leading cause of death in developed countries around the world. Homeostasis of cholesterol is centered on the metabolism of lipoproteins, which mediate transport of the lipid to and from tissues. As a synopsis of the major events and proteins that manage lipoprotein homeostasis, this review contributes to the substantial attention that has recently been directed to this area. Despite intense scrutiny, the majority of phenotypic variation in total cholesterol and related traits eludes explanation by current genetic knowledge. This is somewhat disappointing considering heritability estimates have established these traits as highly genetic. Thus, the continued search for candidate genes, mutations, and mechanisms is vital to our understanding of heart disease at the molecular level. Furthermore, as marker development continues to predict risk of vascular illness, this knowledge has the potential to revolutionize treatment of this leading human disease.

  4. Bagging constrained equity premium predictors

    DEFF Research Database (Denmark)

    Hillebrand, Eric; Lee, Tae-Hwy; Medeiros, Marcelo

    2014-01-01

    regression coefficient and positivity of the forecast. Bagging constrained estimators can have smaller asymptotic mean-squared prediction errors than forecasts from a restricted model without bagging. Monte Carlo simulations show that forecast gains can be achieved in realistic sample sizes for the stock...

  5. The Constrained Bottleneck Transportation Problem

    OpenAIRE

    Peerayuth Charnsethikul; Saeree Svetasreni

    2007-01-01

    Two classes of the bottleneck transportation problem with an additional budget constraint are introduced. An exact approach was proposed to solve both problem classes with proofs of correctness and complexity. Moreover, the approach was extended to solve a class of multi-commodity transportation network with a special case of the multi-period constrained bottleneck assignment problem.

  6. Constrained Clustering With Imperfect Oracles.

    Science.gov (United States)

    Zhu, Xiatian; Loy, Chen Change; Gong, Shaogang

    2016-06-01

    While clustering is usually an unsupervised operation, there are circumstances where we have access to prior belief that pairs of samples should (or should not) be assigned with the same cluster. Constrained clustering aims to exploit this prior belief as constraint (or weak supervision) to influence the cluster formation so as to obtain a data structure more closely resembling human perception. Two important issues remain open: 1) how to exploit sparse constraints effectively and 2) how to handle ill-conditioned/noisy constraints generated by imperfect oracles. In this paper, we present a novel pairwise similarity measure framework to address the above issues. Specifically, in contrast to existing constrained clustering approaches that blindly rely on all features for constraint propagation, our approach searches for neighborhoods driven by discriminative feature selection for more effective constraint diffusion. Crucially, we formulate a novel approach to handling the noisy constraint problem, which has been unrealistically ignored in the constrained clustering literature. Extensive comparative results show that our method is superior to the state-of-the-art constrained clustering approaches and can generally benefit existing pairwise similarity-based data clustering algorithms, such as spectral clustering and affinity propagation. PMID:25622327

  7. The glycoinositol phospholipids of Leishmania mexicana promastigotes. Evidence for the presence of three distinct pathways of glycolipid biosynthesis.

    Science.gov (United States)

    McConville, M J; Collidge, T A; Ferguson, M A; Schneider, P

    1993-07-25

    Most macromolecules at the cell surface of parasitic protozoa of the genus Leishmania, including the major surface glycoproteins and a complex lipophosphoglycan (LPG), are attached to the plasma membrane via glycosyl-phosphatidylinositol (GPI) anchors. Free glycoinositol phospholipids (GIPLs) which are not linked to protein or phosphoglycan have also been found. In this study, we show that L. mexicana promastigotes synthesize two distinct GIPL lineages, comprising at least 10 glycolipid species. These structures were characterized using a combination of gas-liquid chromatography-mass spectrometry, methylation linkage analysis, and chemical and exoglycosidase sequencing. The major lineage contains GIPLs with the glycan structures Man alpha 1-3Man alpha 1-4GlcN (iM2), Man alpha 1-6(Man alpha 1-3)Man alpha 1-4GlcN (iM3), and Man alpha 1-2Man alpha 1-6(Man alpha 1-3)Man alpha 1-4GlcN (iM4), which are linked to alkylacyl-PI containing predominantly C16:0 and C18:0 fatty acids and C18:0 alkyl chains (referred to as the hybrid type GIPLs). A proportion of the iM3 and iM4 species (32 and 4%, respectively) are substituted with an ethanolamine-phosphate residue. The location of this residue on the core glucosamine residue was inferred from the results of methylation analyses and alpha-mannosidase digestion. The minor GIPL lineage contains GIPLs with the same glycan sequences as the glycolipid anchor of LPG (referred to as the type-2 GIPLs). The alkylacyl-PI or lyso-alkyl-PI lipid moieties of these GIPLs differ from those of the hybrid type GIPLs and from the main pool of alkylacyl-PI in containing significant levels of C24:0 and C26:0 alkyl chains. The most polar of these GIPLs, LPGp, has the properties expected of a biosynthetic precursor to the LPG, having the structure, [formula: see text] Finally, the GPI anchors of the major promastigote proteins were found to contain the glycan sequence Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN, and an alkylacyl-PI lipid moiety which

  8. Aspirin Increases the Solubility of Cholesterol in Lipid Membranes

    Science.gov (United States)

    Alsop, Richard; Barrett, Matthew; Zheng, Sonbo; Dies, Hannah; Rheinstadter, Maikel

    2014-03-01

    Aspirin (ASA) is often prescribed for patients with high levels of cholesterol for the secondary prevention of myocardial events, a regimen known as the Low-Dose Aspirin Therapy. We have recently shown that Aspirin partitions in lipid bilayers. However, a direct interplay between ASA and cholesterol has not been investigated. Cholesterol is known to insert itself into the membrane in a dispersed state at moderate concentrations (under ~37.5%) and decrease fluidity of membranes. We prepared model lipid membranes containing varying amounts of both ASA and cholesterol molecules. The structure of the bilayers as a function of ASA and cholesterol concentration was determined using high-resolution X-ray diffraction. At cholesterol levels of more than 40mol%, immiscible cholesterol plaques formed. Adding ASA to the membranes was found to dissolve the cholesterol plaques, leading to a fluid lipid bilayer structure. We present first direct evidence for an interaction between ASA and cholesterol on the level of the cell membrane.

  9. Ordering effects of cholesterol and its analogues

    DEFF Research Database (Denmark)

    Róg, Tomasz; Pasenkiewicz-Gierula, Marta; Vattulainen, Ilpo;

    2009-01-01

    Without any exaggeration, cholesterol is one of the most important lipid species in eukaryotic cells. Its effects on cellular membranes and functions range from purely mechanistic to complex metabolic ones, besides which it is also a precursor of the sex hormones (steroids) and several vitamins. In...... this review, we discuss the biophysical effects of cholesterol on the lipid bilayer, in particular the ordering and condensing effects, concentrating on the molecular level or inter-atomic interactions perspective, starting from two-component systems and proceeding to many-component ones e.g., modeling...... lipid rafts. Particular attention is paid to the roles of the methyl groups in the cholesterol ring system, and their possible biological function. Although our main research methodology is computer modeling, in this review we make extensive comparisons between experiments and different modeling...

  10. CHOBIMALT: A Cholesterol-Based Detergent†

    Science.gov (United States)

    Howell, Stanley C.; Mittal, Ritesh; Huang, Lijun; Travis, Benjamin; Breyer, Richard M.; Sanders, Charles R.

    2010-01-01

    Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins, but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address these problems a cholesterol-based detergent, CHOBIMALT, has been synthesized and characterized. At concentrations above 3–4μM, CHOBIMALT forms micelles without the need for elevated temperatures or sonic disruption. Diffusion and fluorescence measurements indicated that CHOBIMALT micelles are large (210 ± 30 kDa). The ability to solubilize a functional membrane protein was explored using a G-protein coupled receptor, the human kappa opioid receptor type 1 (hKOR1). While CHOBIMALT alone was not found to be effective as a surfactant for membrane extraction, when added to classical detergent micelles CHOBIMALT was observed to dramatically enhance the thermal stability of solubilized hKOR1. PMID:20919740

  11. Increased plasma membrane cholesterol in cystic fibrosis cells correlates with CFTR genotype and depends on de novo cholesterol synthesis

    Directory of Open Access Journals (Sweden)

    Sonawane Nitin D

    2010-05-01

    Full Text Available Abstract Background Previous observations demonstrate that Cftr-null cells and tissues exhibit alterations in cholesterol processing including perinuclear cholesterol accumulation, increased de novo synthesis, and an increase in plasma membrane cholesterol accessibility compared to wild type controls. The hypothesis of this study is that membrane cholesterol accessibility correlates with CFTR genotype and is in part influenced by de novo cholesterol synthesis. Methods Electrochemical detection of cholesterol at the plasma membrane is achieved with capillary microelectrodes with a modified platinum coil that accepts covalent attachment of cholesterol oxidase. Modified electrodes absent cholesterol oxidase serves as a baseline control. Cholesterol synthesis is determined by deuterium incorporation into lipids over time. Incorporation into cholesterol specifically is determined by mass spectrometry analysis. All mice used in the study are on a C57Bl/6 background and are between 6 and 8 weeks of age. Results Membrane cholesterol measurements are elevated in both R117H and ΔF508 mouse nasal epithelium compared to age-matched sibling wt controls demonstrating a genotype correlation to membrane cholesterol detection. Expression of wt CFTR in CF epithelial cells reverts membrane cholesterol to WT levels further demonstrating the impact of CFTR on these processes. In wt epithelial cell, the addition of the CFTR inhibitors, Gly H101 or CFTRinh-172, for 24 h surprisingly results in an initial drop in membrane cholesterol measurement followed by a rebound at 72 h suggesting a feedback mechanism may be driving the increase in membrane cholesterol. De novo cholesterol synthesis contributes to membrane cholesterol accessibility. Conclusions The data in this study suggest that CFTR influences cholesterol trafficking to the plasma membrane, which when depleted, leads to an increase in de novo cholesterol synthesis to restore membrane content.

  12. Anti-phenolic glycolipid-I (PGL-I determination using blood collection on filter paper in leprosy patients

    Directory of Open Access Journals (Sweden)

    TOMIMORI-YAMASHITA Jane

    1999-01-01

    Full Text Available The authors studied 70 leprosy patients and 20 normal individuals, comparing the traditional sera collection method and the finger prick blood with the conservation on filter paper for specific antibodies against the native phenolic glycolipid-I (PGL-I from Mycobacterium leprae. The finger prick blood dried on filter paper was eluated in phosphate buffer saline (PBS containing 0.5% gelatin. The classical method for native PGL-I was performed for these eluates, and compared with the antibody determination for sera. It was observed that there is a straight correlation comparing these two methods; although the titles found for the eluates were lower than those obtained for serology. This blood collection method could be useful for investigation of new leprosy cases in field, specially in contacts individuals.

  13. The cholesterol system of the swine

    International Nuclear Information System (INIS)

    The purpose of this work was to characterize the dynamic system of adult female Large White swine. The content of this system and its relationships with both the external environment and between the different parts of the system were explained. The analysis of these results in terms of compared physiology showed that the structure of the cholesterol system was the same in man and in the swine. Consequently, the swine constitutes a good biological tool to study human cholesterol indirectly and to foresee the changes that might be induced in various physio-pathological cases. (author)

  14. Electron Transfer Pathways in Cholesterol Synthesis.

    Science.gov (United States)

    Porter, Todd D

    2015-10-01

    Cholesterol synthesis in the endoplasmic reticulum requires electron input at multiple steps and utilizes both NADH and NADPH as the electron source. Four enzymes catalyzing five steps in the pathway require electron input: squalene monooxygenase, lanosterol demethylase, sterol 4α-methyl oxidase, and sterol C5-desaturase. The electron-donor proteins for these enzymes include cytochrome P450 reductase and the cytochrome b5 pathway. Here I review the evidence for electron donor protein requirements with these enzymes, the evidence for additional electron donor pathways, and the effect of deletion of these redox enzymes on cholesterol and lipid metabolism. PMID:26344922

  15. Analysis of Cholesterol Trafficking with Fluorescent Probes

    DEFF Research Database (Denmark)

    Maxfield, Frederick R.; Wustner, Daniel

    2012-01-01

    processes are not well understood. Fluorescence microscopy is a valuable tool for studying intracellular transport processes, but this method can be challenging for lipid molecules because addition of a fluorophore may alter the properties of the molecule greatly. We discuss the use of fluorescent molecules...... that can bind to cholesterol to reveal its distribution in cells. We also discuss the use of intrinsically fluorescent sterols that closely mimic cholesterol, as well as some minimally modified fluorophore-labeled sterols. Methods for imaging these sterols by conventional fluorescence microscopy and by...

  16. From blood to gut: Direct secretion of cholesterol via transintestinal cholesterol efflux

    Directory of Open Access Journals (Sweden)

    Carlos LJ Vrins

    2010-12-01

    Full Text Available The reverse cholesterol transport pathway (RCT is the focus of many cholesterol-lowering therapies. By way of this pathway, excess cholesterol is collected from peripheral tissues and delivered back to the liver and gastrointestinal tract for excretion from the body. For a long time this removal via the hepatobiliary secretion was considered to be the sole route involved in the RCT. However, observations from early studies in animals and humans already pointed towards the possibility of another route. In the last few years it has become evident that a non-biliary cholesterol secretion pathway exists in which the intestine plays a central role. This transintestinal cholesterol efflux (TICE pathway contributes significantly to the total fecal neutral sterol excretion. Moreover, recent studies have shown that TICE is also sensitive to stimulation. As a consequence, the direct role of cholesterol secretion from blood via TICE makes the intestine a suitable and approachable target for cholesterol removal from the body and possibly reduction of atherosclerosis. In this review, the discovery and recent findings contributing to understanding the mechanism of TICE will be discussed.

  17. Effect of Processing Methods on Cholesterol Contents and Cholesterol Oxides Formation in Some Dairy Products

    International Nuclear Information System (INIS)

    The effects of pasteurization, boiling, microwaving, processing and storage of milk and some locally produced dairy products on cholesterol contents and cholesterol oxides formation were studied and evaluated. The 7-ketocholesterol were not detected (ND) in all raw milk samples. On the contrary, heating of milk led to formation of cholesterol oxidation products (COPs), mostly, 7- ketocholesterol in different quantities. No significant effect of heating of milk on cholesterol level was observed with the exception of the ultra-high temperature (UHT) milk prepared from milk powder heated at 140 + - 1.0 degree C for 4 sec showed the highest value of 7-ketocholesterol (80.97 mgg-1), followed by microwave heated milk for 5 min (31.29 mgg-1), whereas the lowest value was in milk pasteurized at 85 + - 1.0 degree C for 16 sec (3.125 mgg-1). Commercial storage showed no significant effect on cholesterol and 7-ketocholestrol but lowered cholesterol concentration and increased 7-ketocholestrol level of UHT reconstituted milk. Cholesterol content of both yogurt and labaneh strained by centrifugal separator showed significant decrease while 7-ketochostrol level was increased significantly with refrigerated storage. The findings are discussed in the context with the results of previous similar studies. (author)

  18. Cholesterol homeostasis: How do cells sense sterol excess?

    Science.gov (United States)

    Howe, Vicky; Sharpe, Laura J; Alexopoulos, Stephanie J; Kunze, Sarah V; Chua, Ngee Kiat; Li, Dianfan; Brown, Andrew J

    2016-09-01

    Cholesterol is vital in mammals, but toxic in excess. Consequently, elaborate molecular mechanisms have evolved to maintain this sterol within narrow limits. How cells sense excess cholesterol is an intriguing area of research. Cells sense cholesterol, and other related sterols such as oxysterols or cholesterol synthesis intermediates, and respond to changing levels through several elegant mechanisms of feedback regulation. Cholesterol sensing involves both direct binding of sterols to the homeostatic machinery located in the endoplasmic reticulum (ER), and indirect effects elicited by sterol-dependent alteration of the physical properties of membranes. Here, we examine the mechanisms employed by cells to maintain cholesterol homeostasis. PMID:26993747

  19. Dynamic micelles of mannoside glycolipids are more efficient than polymers for inhibiting HIV-1 trans-infection.

    Science.gov (United States)

    Schaeffer, Evelyne; Dehuyser, Laure; Sigwalt, David; Flacher, Vincent; Bernacchi, Serena; Chaloin, Olivier; Remy, Jean-Serge; Mueller, Christopher G; Baati, Rachid; Wagner, Alain

    2013-11-20

    Mannoside glycolipid conjugates are able to inhibit human immunodeficiency virus type 1 (HIV-1) trans-infection mediated by human dendritic cells (DCs). The conjugates are formed by three building blocks: a linear or branched mannose head, a hydrophilic linker, and a 24-carbon lipid chain. We have shown that, even as single molecules, these compounds efficiently target mannose-binding lectins, such as DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN) important for HIV-1 transmission. With the goal to optimize their inhibitory activity by supramolecular structure formation, we have compared saturated and unsaturated conjugates, as single molecules, self-assemblies of dynamic micelles, and photopolymerized cross-linked polymers. Surface plasmon resonance showed that, unexpectedly, polymers of trivalent conjugates did not display a higher binding affinity for DC-SIGN than single molecules. Interactions on a chip or in solution were independent of calcium; however, binding to DCs was inhibited by a calcium chelator. Moreover, HIV-1 trans-infection was mostly inhibited by dynamic micelles and not by rigid polymers. The inhibition data revealed a clear correlation between the structure and molecular assembly of a conjugate and its biological antiviral activity. We present an interaction model between DC-SIGN and conjugates-either single molecules, micelles, or polymers-that highlights that the most effective interactions by dynamic micelles involve both mannose heads and lipid chains. Our data reveal that trivalent glycolipid conjugates display the highest microbicide potential for HIV prophylaxis, as dynamic micelles conjugates and not as rigid polymers. PMID:24134734

  20. Production and characterization of a glycolipid biosurfactant, mannosylerythritol lipid B, from sugarcane juice by Ustilago scitaminea NBRC 32730.

    Science.gov (United States)

    Morita, Tomotake; Ishibashi, Yuko; Hirose, Naoto; Wada, Koji; Takahashi, Makoto; Fukuoka, Tokuma; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2011-01-01

    Mannosylerythritol lipids (MELs) are glycolipid biosurfactants excreted by fungal strains. They show not only excellent surface-active properties but also versatile biochemical actions. Ustilago scitaminea NBRC 32730 has been reported mainly to produce a mono-acetylated and di-acylated MEL, MEL-B, from sucrose as sole carbon source. In order to make biosurfactant production more efficient, we focused our attention on the use of sugarcane juice, one of the most economical resources. The fungal strain produced MEL-B at the yield of 12.7 g/L from only sugarcane juice containing 22.4% w/w sugars. Supplementation with organic (yeast extract, peptone, and urea) and inorganic (sodium nitrate and ammonium nitrate) nitrogen sources markedly enhanced the production yield. Of the nitrogen sources, urea gave the best yield. Under optimum conditions, the strain produced 25.1 g/L of MEL-B from the juice (19.3% sugars) supplemented with 1 g/L of urea in a jar fermenter at 25 °C over 7 d. The critical micelle concentration (CMC) and the surface-tension at the CMC for the present MEL-B were 3.7×10(-6) M and 25.2 mN/m respectively. On water-penetration scan, the biosurfactant efficiently formed the lamella phase (L(α)) and myelins over a wide range of concentrations, indicating excellent surface-active and self-assembling properties. More significantly, the biosurfactant showed a ceramide-like skin-care property in a three-dimensional cultured human skin model. Thus, sugarcane juice is likely to be effective in glycolipid production by U. scitaminea NBRC 32730, and should facilitate the application of MELs. PMID:21737925

  1. IDENTIFICATION OF PSEUDOZYMA HUBEIENSIS Y10BS025 AS A POTENT PRODUCER OF GLYCOLIPID BIOSURFACTANT MANNOSYLERYTHRITOL LIPIDS

    Directory of Open Access Journals (Sweden)

    Martha Sari

    2013-01-01

    Full Text Available Mannosylerythritol Lipids (MEL’s are glycolipid biosurfactants that contain 4-O-β-D-mannopyranosyl-meso-erythritol as a hydrophilic moiety and fatty acids as a hydrophobic moiety. MEL’s are abundantly produced by several kinds of microorganism and are one of the most promising biosurfactants currently known. The search for a novel endogenous producer of MEL’s was undertaken based on the available collection of the yeast strains from the genus Pseudozyma. Using thin layer chromatography and based on morphological and molecular taxonomic analysis using the D1/D2 domains of the large subunit 26S rRNA gene, Pseudozyma hubeiensis Y10BS025 was found to be a potential producer of MEL’s from soybean oil. The structure of the major glycolipid produced by the strain was analyzed by 1H and 13C nuclear magnetic resonance and was found to be similar to those of well known MEL-A, -B and -C respectively. Under improved shaking culture conditions, using yeast extract as nitrogen source and soybean oil as substrate, a maximum yield of 115±3.2 g.L-1 of MEL’s for 8 days of fermentation was achieved. The major fatty acids of MEL’s produced by P. hubeiensis Y10BS025 were C-18 acids, considerably different from those of MEL-C produced by other Pseudozyma strains such as P. antarctica and P. shanxiensis. The main product, MEL-C produced by P. hubeiensis Y10BS025 exhibited surface-tension-lowering activity. The results demonstrated that the newly isolated P. hubeiensis Y10BS025 provided high efficiency in MEL’s production and would thus be highly advantageous in commercial production of promising biosurfactants.

  2. Cholesterol versus cholesterol sulfate: effects on properties of phospholipid bilayers containing docosahexaenoic acid.

    Science.gov (United States)

    Schofield, M; Jenski, L J; Dumaual, A C; Stillwell, W

    1998-09-01

    The important omega-3 fatty acid docosahexaenoic acid (DHA) is present at high concentration in some membranes that also contain the unusual sterol cholesterol sulfate (CS). The association between these lipids and their effect on membrane structure is presented here. Differential scanning calorimetry (DSC), MC540 fluorescence, erythritol permeability, pressure/area isotherms on lipid monolayers and molecular modeling are used to compare the effect of CS and cholesterol on model phospholipid membranes. By DSC, CS decreases the main phase transition temperature and broadens the transitions of dipalmitolyphosphatidylcholine (DPPC), 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (18:0,18:1 PC) and 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (18:0,22:6 PC) to a much larger extent than does cholesterol. In addition CS produces a three-component transition in 18:0,18:1 PC bilayers that is not seen with cholesterol. In a mixed phospholipid bilayer composed of 18:0,18:1 PC/18:0,22:6 PC (1:1, mol/mol), CS at 2.5 membrane mol% or more induces lateral phase separation while cholesterol does not. CS decreases lipid packing density and increases permeability of 18:0,18:1 PC and 18:0,22:6 PC bilayers to a much larger extent than cholesterol. CS disrupts oleic acid-containing bilayers more than those containing DHA. Molecular modeling confirms that the anionic sulfate moiety on CS renders this sterol more polar than cholesterol with the consequence that CS likely resides higher (extends further into the aqueous environment) in the bilayer. CS can therefore be preferentially accommodated into DHA-enriched bilayers where its tetracyclic ring system may fit into the delta 4 pocket of DHA, a location excluded to cholesterol. It is proposed that CS may in part replace the membrane function of cholesterol in DHA-rich membranes. PMID:9807808

  3. Potential of BODIPY-cholesterol for analysis of cholesterol transport and diffusion in living cells

    DEFF Research Database (Denmark)

    Wüstner, Daniel; Lund, Frederik Wendelboe; Röhrl, Clemens; Stangl, Herbert

    2016-01-01

    Cholesterol is an abundant and important lipid component of cellular membranes. Analysis of cholesterol transport and diffusion in living cells is hampered by the technical challenge of designing suitable cholesterol probes which can be detected for example by optical microscopy. One strategy is to...... collaborative efforts with Bob Bittman for studying diffusion in the plasma membrane (PM) and uptake of BChol in a quantitative manner. For that purpose, we used a variety of fluorescence approaches including fluorescence correlation spectroscopy and its imaging variants, fluorescence recovery after...

  4. Constrained Multiobjective Biogeography Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Hongwei Mo

    2014-01-01

    Full Text Available Multiobjective optimization involves minimizing or maximizing multiple objective functions subject to a set of constraints. In this study, a novel constrained multiobjective biogeography optimization algorithm (CMBOA is proposed. It is the first biogeography optimization algorithm for constrained multiobjective optimization. In CMBOA, a disturbance migration operator is designed to generate diverse feasible individuals in order to promote the diversity of individuals on Pareto front. Infeasible individuals nearby feasible region are evolved to feasibility by recombining with their nearest nondominated feasible individuals. The convergence of CMBOA is proved by using probability theory. The performance of CMBOA is evaluated on a set of 6 benchmark problems and experimental results show that the CMBOA performs better than or similar to the classical NSGA-II and IS-MOEA.

  5. Trends in PDE constrained optimization

    CERN Document Server

    Benner, Peter; Engell, Sebastian; Griewank, Andreas; Harbrecht, Helmut; Hinze, Michael; Rannacher, Rolf; Ulbrich, Stefan

    2014-01-01

    Optimization problems subject to constraints governed by partial differential equations (PDEs) are among the most challenging problems in the context of industrial, economical and medical applications. Almost the entire range of problems in this field of research was studied and further explored as part of the Deutsche Forschungsgemeinschaft (DFG) priority program 1253 on “Optimization with Partial Differential Equations” from 2006 to 2013. The investigations were motivated by the fascinating potential applications and challenging mathematical problems that arise in the field of PDE constrained optimization. New analytic and algorithmic paradigms have been developed, implemented and validated in the context of real-world applications. In this special volume, contributions from more than fifteen German universities combine the results of this interdisciplinary program with a focus on applied mathematics.   The book is divided into five sections on “Constrained Optimization, Identification and Control”...

  6. Constrained ballistics and geometrical optics

    OpenAIRE

    Epstein, Marcelo

    2014-01-01

    The problem of constant-speed ballistics is studied under the umbrella of non-linear non-holonomic constrained systems. The Newtonian approach is shown to be equivalent to the use of Chetaev's rule to incorporate the constraint within the initially unconstrained formulation. Although the resulting equations are not, in principle, obtained from a variational statement, it is shown that the trajectories coincide with those of geometrical optics in a medium with a suitably chosen refractive inde...

  7. Bagging Constrained Equity Premium Predictors

    OpenAIRE

    Tae-Hwy Lee; Eric Hillebrand; Marcelo Medeiros

    2013-01-01

    The literature on excess return prediction has considered a wide array of estimation schemes, among them unrestricted and restricted regression coefficients. We consider bootstrap aggregation (bagging) to smooth parameter restrictions. Two types of restrictions are considered: positivity of the regression coefficient and positivity of the forecast. Bagging constrained estimators can have smaller asymptotic mean-squared prediction errors than forecasts from a restricted model without bagging. ...

  8. Biliary cholesterol secretion: More than a simple ABC

    Directory of Open Access Journals (Sweden)

    Arne Dikkers, Uwe JF Tietge

    2010-12-01

    Full Text Available Biliary cholesterol secretion is a process important for 2 major disease complexes, atherosclerotic cardiovascular disease and cholesterol gallstone disease. With respect to cardiovascular disease, biliary cholesterol secretion is regarded as the final step for the elimination of cholesterol originating from cholesterol-laden macrophage foam cells in the vessel wall in a pathway named reverse cholesterol transport. On the other hand, cholesterol hypersecretion into the bile is considered the main pathophysiological determinant of cholesterol gallstone formation. This review summarizes current knowledge on the origins of cholesterol secreted into the bile as well as the relevant processes and transporters involved. Next to the established ATP-binding cassette (ABC transporters mediating the biliary secretion of bile acids (ABCB11, phospholipids (ABCB4 and cholesterol (ABCG5/G8, special attention is given to emerging proteins that modulate or mediate biliary cholesterol secretion. In this regard, the potential impact of the phosphatidylserine flippase ATPase class I type 8B member 1, the Niemann Pick C1-like protein 1 that mediates cholesterol absorption and the high density lipoprotein cholesterol uptake receptor, scavenger receptor class B type I, is discussed.

  9. Effects of apolipoproteins on the kinetics of cholesterol exchange

    Energy Technology Data Exchange (ETDEWEB)

    Letizia, J.Y.; Phillips, M.C. (Medical College of Pennsylvania, Philadelphia (USA))

    1991-01-22

    The effects of apolipoproteins on the kinetics of cholesterol exchange have been investigated by monitoring the transfer of ({sup 14}C)cholesterol from donor phospholipid/cholesterol complexes containing human apolipoproteins A, B, or C. Negatively charged discoidal and vesicular particles containing purified apolipoproteins complexed with lipid and a trace of ({sup 14}C)cholesterol were incubated with a 10-fold excess of neutral, acceptor, small unilamellar vesicles. The donor and acceptor particles were separated by chromatogrphy of DEAE-Sepharose, and the rate of movement of labeled cholesterol was analyzed as a first-order exchange process. The kinetics of exchange of cholesterol from both vesicular and discoidal complexes that contain apoproteins are consistent with an aqueous diffusion mechanism, as has been established previously for PC/cholesterol SUV. Apolipoproteins A-I, A-II, reduced and carboxymethylated A-11, and B-100 present in SUV at the same lipid/protein (w/w) ratio all enhance the rate of cholesterol exchange to about the same degree. Cholesterol molecules exchange more rapidly from discoidal complexes. Generally, as the diameter of apoprotein/phospholipid/cholesterol discs decreases, t{sub 1/2} for cholesterol exchange decreases. Since small bilayer discs have a relatively high ratio of boundary to face surface area, cholesterol molecules desorb more rapidly than from larger discs. The modulation of lipid packing by the apoprotein molecules present at the surface of lipoprotein particles affects the rate of cholesterol exchange from such particles.

  10. The Success Story of LDL Cholesterol Lowering.

    Science.gov (United States)

    Pedersen, Terje R

    2016-02-19

    We can look back at >100 years of cholesterol research that has brought medicine to a stage where people at risk of severe or fatal coronary heart disease have a much better prognosis than before. This progress has not come about without resistance. Perhaps one of the most debated topics in medicine, the cholesterol controversy, could only be brought to rest through the development of new clinical research methods that were capable of taking advantage of the amazing achievements in basic and pharmacological science after the second World War. It was only after understanding the biochemistry and physiology of cholesterol synthesis, transport and clearance from the blood that medicine could take advantage of drugs and diets to reduce the risk of atherosclerotic diseases. This review points to the highlights of the history of low-density lipoprotein-cholesterol lowering, with the discovery of the low-density lipoprotein receptor and its physiology and not only the development of statins as the stellar moments but also the development of clinical trial methodology as an effective tool to provide scientifically convincing evidence. PMID:26892969

  11. [Giant cholesterol cysts of the petrous apex].

    Science.gov (United States)

    Pellet, W; Valenzuela, S; Malca, S; Cannoni, M; Perez-Castillo, A M

    1992-01-01

    In connection with their two own cases, the authors deal about the giant cholesterol cysts of the petrous apex. The lesions which are to be differentiated from epidermoid cysts are cholesterol granulomas. Their petrous apex location explains their characteristic large appearance. As each cholesterol granuloma, they occur when a bony cell is obstructed. This chronic obstruction induces mucosal edema then bleedings which lead to the formation and, by the lack of drainage, to the accumulation of cholesterol crystals. These crystals initiate a non specific reaction to foreign bodies, a granuloma, which also can bleed. Thus, a continuous cycle perpetuates the growth of the lesion. This lesion, when it is localized in the petrous apex, can reach a big size before the appearance of some signs. Usually, these are otologic (sensorineural hearing loss, tinnitus, vertigo) and/or cranial nerve palsies (V, VI, VII). C.T. scan (well defined, sharply marginated bony expansible lesion with isodense to the brain central part) and M.R.I. (central region of increased intensity on both T1 and T2 weighted images and peripheral rim of markedly decreased signal intensity in all instances) features are characteristic enough to allow diagnose with other petrous apex lesions (cholesteatoma, mucocele, epithelial cyst, histiocytosis X, ...). Surgical treatment must try to evacuate and to aerate the cavity or perhaps to obliterate it with fatty pieces in order to prevent the recurrence. PMID:1299772

  12. Mitochondria, cholesterol and cancer cell metabolism.

    Science.gov (United States)

    Ribas, Vicent; García-Ruiz, Carmen; Fernández-Checa, José C

    2016-12-01

    Given the role of mitochondria in oxygen consumption, metabolism and cell death regulation, alterations in mitochondrial function or dysregulation of cell death pathways contribute to the genesis and progression of cancer. Cancer cells exhibit an array of metabolic transformations induced by mutations leading to gain-of-function of oncogenes and loss-of-function of tumor suppressor genes that include increased glucose consumption, reduced mitochondrial respiration, increased reactive oxygen species generation and cell death resistance, all of which ensure cancer progression. Cholesterol metabolism is disturbed in cancer cells and supports uncontrolled cell growth. In particular, the accumulation of cholesterol in mitochondria emerges as a molecular component that orchestrates some of these metabolic alterations in cancer cells by impairing mitochondrial function. As a consequence, mitochondrial cholesterol loading in cancer cells may contribute, in part, to the Warburg effect stimulating aerobic glycolysis to meet the energetic demand of proliferating cells, while protecting cancer cells against mitochondrial apoptosis due to changes in mitochondrial membrane dynamics. Further understanding the complexity in the metabolic alterations of cancer cells, mediated largely through alterations in mitochondrial function, may pave the way to identify more efficient strategies for cancer treatment involving the use of small molecules targeting mitochondria, cholesterol homeostasis/trafficking and specific metabolic pathways. PMID:27455839

  13. Practical radiochromatographic assay for cholesterol epoxide hydrase

    International Nuclear Information System (INIS)

    A method for the assay of cholesterol epoxide hydrase activity is described. The assay involves the thin-layer chromatographic separation and quantitation of radiolabeled cholestan-3β,5α,6α-epoxide and its major hydration product, cholestan-3β,5α,6β-triol. Radiochromatographic scanning is employed to quantitate the reaction. The procedure is sensitive, rapid, and nondestructive

  14. Weight Loss Surgery May Boost Good Cholesterol in Obese Boys

    Science.gov (United States)

    ... or federal policy. More Health News on: Cholesterol Obesity in Children Weight Loss Surgery Recent Health News Related MedlinePlus Health Topics Cholesterol Obesity in Children Weight Loss Surgery About MedlinePlus Site Map FAQs ...

  15. Cholesterol-induced protein sorting: an analysis of energetic feasibility

    DEFF Research Database (Denmark)

    Lundbaek, J A; Andersen, O S; Werge, T;

    2003-01-01

    thickness. In this model, Golgi proteins with short TMDs would be excluded from cholesterol-enriched domains (lipid rafts) that are incorporated into transport vesicles destined for the plasma membrane. Although attractive, this model remains unproven. We therefore evaluated the energetic feasibility of a...... cholesterol-dependent sorting process using the theory of elastic liquid crystal deformations. We show that the distribution of proteins between cholesterol-enriched and cholesterol-poor bilayer domains can be regulated by cholesterol-induced changes in the bilayer physical properties. Changes in bilayer...... thickness per se, however, have only a modest effect on sorting; the major effect arises because cholesterol changes also the bilayer material properties, which augments the energetic penalty for incorporating short TMDs into cholesterol-enriched domains. We conclude that cholesterol-induced changes in the...

  16. Plasma Ubiquinone, Alpha-Tocopherol and Cholesterol in Man

    DEFF Research Database (Denmark)

    Karlsson, Jan; Diamant, Bertil; Edlund, Per Olof;

    1992-01-01

    Farmakologi, Coenzyme Q10, free cholesterol, vitamin E, antioxidants, Alpha-Tocopherol, vitamin Q, plasma, LDL-particle......Farmakologi, Coenzyme Q10, free cholesterol, vitamin E, antioxidants, Alpha-Tocopherol, vitamin Q, plasma, LDL-particle...

  17. Trans Fat Now Listed With Saturated Fat and Cholesterol

    Science.gov (United States)

    ... Trans Fat Now Listed With Saturated Fat and Cholesterol Share Tweet Linkedin Pin it More sharing options ... I Do About Saturated Fat, Trans Fat, and Cholesterol? When comparing foods, look at the Nutrition Facts ...

  18. Nonfasting triglycerides, cholesterol, and ischemic stroke in the general population

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G; Tybjaerg-Hansen, Anne;

    2011-01-01

    Current guidelines on stroke prevention have recommendations on desirable cholesterol levels, but not on nonfasting triglycerides. We compared stepwise increasing levels of nonfasting triglycerides and cholesterol for their association with risk of ischemic stroke in the general population....

  19. Talk with Your Health Care Provider about High Cholesterol

    Science.gov (United States)

    ... you do? Always ask your provider what your cholesterol numbers are and write them down. Discuss these ... provider may prescribe medicine to help lower your cholesterol. y y Take your medicine every day, or ...

  20. Hearing Outcomes after Surgical Drainage of Petrous Apex Cholesterol Granuloma

    OpenAIRE

    Rihani, Jordan; Kutz, J. Walter; Isaacson, Brandon

    2014-01-01

    Objective This study aims to assess the hearing outcomes of patients undergoing surgical management of petrous apex cholesterol granuloma and to discuss the role of otic capsule–sparing approaches in drainage of petrous apex cholesterol granulomas.

  1. Enzymatic Quantification of Cholesterol and Cholesterol Esters from Silicone Hydrogel Contact Lenses

    OpenAIRE

    Pucker, Andrew D.; Thangavelu, Mirunalni; Nichols, Jason J.

    2010-01-01

    There is significant interest in lipid deposition associated with current silicone hydrogel contact lens materials. This work describes the application of a cholesterol assay used to examine this question.

  2. Fluorimetric determination of cholesterol in hypercholesterolemia serum

    Science.gov (United States)

    Lan, Xiufeng; Liu, Jiangang; Liu, Ying; Luo, Xiaosen; Lu, Jian; Ni, Xiaowu

    2005-01-01

    With the increase of people"s living standard and the changes of living form, the number of people who suffer from hypercholesterolemia is increasing. It is not only harmful to heart and blood vessel, but also leading to obstruction of cognition. The conventional blood detection technology has weakness such as complex operation, long detecting period, and bad visibility. In order to develop a new detection method that can checkout hypercholesterolemia conveniently, spectroscopy of cholesterol in hypercholesterolemia serum is obtained by the multifunctional grating spectrograph. The experiment results indicate that, under the excitation of light-emitting diode (LED) with the wavelength at 407 nm, the serum from normal human and the hypercholesterolemia serum emit different fluorescence spectra. The former can emit one fluorescence region with the peak locating at 516 nm while the latter can emit two more regions with peaks locating at 560 nm and 588 nm. Moreover, the fluorescence intensity of serum is non-linear increasing with the concentration of cholesterol increases when the concentration of cholesterol is lower than 13.8 mmol/L, and then, with the concentration of cholesterol increase, the fluorescence intensity decreases. However, the fluorescence intensity is still much higher than that of serum from normal human. Conclusions can be educed from the experiments: the intensity and the shape of fluorescence spectra of hypercholesterolemia serum are different of those of normal serum, from which the cholesterol abnormal in blood can be judged. The consequences in this paper may offer an experimental reference for the diagnosis of the hypercholesterolemia.

  3. Effect of dietary cholesterol on plasma cholesterol concentration in subjects following reduced fat, high fibre diet.

    OpenAIRE

    Edington, J.; Geekie, M; Carter, R.; Benfield, L; Fisher, K; Ball, M.; J. Mann

    1987-01-01

    One hundred and sixty eight subjects participated in a randomised crossover study to determine whether halving or doubling the present dietary cholesterol intake from eggs had any influence on blood cholesterol concentration in people following current dietary recommendations. During the first eight weeks all participants were advised to follow a reduced fat diet (26% total energy for hyperlipidaemic patients, 35% total energy for normolipidaemic volunteers) with an increased ratio of polyuns...

  4. Electron Microscopic Localization of Cholesterol in Bovine Milk Fat Globules

    OpenAIRE

    Martin, Robert W.

    1989-01-01

    An electron microscopic method designed for the detection of cholesterol in milk fat was evaluated for reliability. This method is based on the incubation of cream from raw milk with fillipin (a polyene antibiotic) which has a specific affinity for cholesterol followed by freeze fracturing and electron microscopic examination of fat globules. Cholesterol was localized within the membrane and the triglyceride core of milk fat globules. Cholesterol was highly organized within membrane portio...

  5. Remnant cholesterol as a cause of ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Nordestgaard, Børge G

    2014-01-01

    This review focuses on remnant cholesterol as a causal risk factor for ischemic heart disease (IHD), on its definition, measurement, atherogenicity, and levels in high risk patient groups; in addition, present and future pharmacological approaches to lowering remnant cholesterol levels...... are considered. Observational studies show association between elevated levels of remnant cholesterol and increased risk of cardiovascular disease, even when remnant cholesterol levels are defined, measured, or calculated in different ways. In-vitro and animal studies also support the contention that elevated...

  6. Cholesterol esterification during differentiation of mouse erythroleukemia (Friend) cells

    OpenAIRE

    Maria Franca Mulas; Antonella Mandas; Claudia Abete; Sandra Dessì; Alessandra Mocali; Francesco Paoletti

    2011-01-01

    Cholesterol is an essential constituent of all mammalian cell membranes, and its availability is therefore a prerequisite for cellular growth and other functions. Several lines of evidence are now indicating an association between alterations of cholesterol homeostasis and cell cycle progression. However, the role of cholesterol in cell differentiation is still largely unknown. To begin to address this issue, in this study we examined changes in cholesterol metabolism and in the mRNA levels o...

  7. Polymer sorbent with the properties of an artificial cholesterol receptor

    Science.gov (United States)

    Polyakova, I. V.; Ezhova, N. M.; Osipenko, A. A.; Pisarev, O. A.

    2015-02-01

    A cholesterol-imprinted polymer sorbent and the corresponding reticular control copolymer were synthesized from hydroxyethyl methacrylate and ethyleneglycol dimethacrylate. The sorption isotherms of cholesterol were analyzed using the generalized Langmuir and Freundlich equations. In the case of the imprinted reticular polymer, cholesterol sorption occurred on the energetically homogeneous binding centers, forming one monolayer, while the nonspecific sorption of cholesterol on the control copolymer occurred with energetically nonhomogeneous binding of the sorbate and depended on the physicochemical conditions of sorption.

  8. Ezetimibe and Simvastatin Reduce Cholesterol Levels in Zebrafish Larvae Fed a High-Cholesterol Diet

    Directory of Open Access Journals (Sweden)

    Ji Sun Baek

    2012-01-01

    Full Text Available Cholesterol-fed zebrafish is an emerging animal model to study metabolic, oxidative, and inflammatory vascular processes relevant to pathogenesis of human atherosclerosis. Zebrafish fed a high-cholesterol diet (HCD develop hypercholesterolemia and are characterized by profound lipoprotein oxidation and vascular lipid accumulation. Using optically translucent zebrafish larvae has the advantage of monitoring vascular pathology and assessing the efficacy of drug candidates in live animals. Thus, we investigated whether simvastatin and ezetimibe, the principal drugs used in management of hypercholesterolemia in humans, would also reduce cholesterol levels in HCD-fed zebrafish larvae. We found that ezetimibe was well tolerated by zebrafish and effectively reduced cholesterol levels in HCD-fed larvae. In contrast, simvastatin added to water was poorly tolerated by zebrafish larvae and, when added to food, had little effect on cholesterol levels in HCD-fed larvae. Combination of low doses of ezetimibe and simvastatin had an additive effect in reducing cholesterol levels in zebrafish. These results suggest that ezetimibe exerts in zebrafish a therapeutic effect similar to that in humans and that the hypercholesterolemic zebrafish can be used as a low-cost and informative model for testing new drug candidates and for investigating mechanisms of action for existing drugs targeting dyslipidemia.

  9. Cholesterol Assimilation by Lactobacillus Probiotic Bacteria: An In Vitro Investigation

    OpenAIRE

    Catherine Tomaro-Duchesneau; Mitchell L. Jones; Divya Shah; Poonam Jain; Shyamali Saha; Satya Prakash

    2014-01-01

    Excess cholesterol is associated with cardiovascular diseases (CVD), an important cause of mortality worldwide. Current CVD therapeutic measures, lifestyle and dietary interventions, and pharmaceutical agents for regulating cholesterol levels are inadequate. Probiotic bacteria have demonstrated potential to lower cholesterol levels by different mechanisms, including bile salt hydrolase activity, production of compounds that inhibit enzymes such as 3-hydroxy-3-methylglutaryl coenzyme A, and ch...

  10. CHROMATOGRAPHIC METHODS IN THE ANALYSIS OF CHOLESTEROL AND RELATED LIPIDS

    NARCIS (Netherlands)

    HOVING, EB

    1995-01-01

    Methods using thin-layer chromatography, solid-phase extraction, gas chromatography, high-performance liquid chromatography and supercritical fluid chromatography are described for the analysis of single cholesterol, esterified and sulfated cholesterol, and for cholesterol in the context of other li

  11. Hypercholesterolemia: The Role of Schools in Cholesterol Screening.

    Science.gov (United States)

    Price, James H.; Casler, Suzanne M.

    1997-01-01

    Examines the prevalence of cardiovascular disease risk factors among children and adolescents, the pros and cons of cholesterol screening among youth, cholesterol assessments of at-risk youth, and the role of schools in cholesterol education and screening (focusing on comprehensive school health education and services). (SM)

  12. Porcine artery elastin preparation reduces serum cholesterol level in rats

    OpenAIRE

    Liyanage, Ruvini; Nakamura, Yumi; Shimada, Ken-ichiro; SEKIKAWA, Mitsuo; Jayawardana, Barana Chaminda; HAN, Kyu-Ho; Tomoko, Okada; Ohba, Kiyoshi; Takahata, Yoshihisa; Morimatsu, Fumiki; FUKUSHIMA, Michihiro; 福島, 道広; 島田, 謙一郎; 関川, 三男; 韓, 圭鎬

    2009-01-01

    The effect of porcine artery elastin on serum cholesterol level was investigated in rats fed a cholesterol-free diet. Rats were fed for 4 weeks, with a diet (ED) containing 15% casein and 5% of porcine artery elastin in comparison with a diet (CD) containing 20% casein. The total serum and non-HDL-cholesterol concentrations were lower (P

  13. Emerging roles of the intestine in control of cholesterol metabolism

    NARCIS (Netherlands)

    J.K. Kruit; A.K. Groen; T.J. van Berkel; F. Kuipers

    2006-01-01

    The liver is considered the major "control center" for maintenance of whole body cholesterol homeostasis. This organ is the main site for de novo cholesterol synthesis, clears cholesterol-containing chylomicron remnants and low density lipoprotein particles from plasma and is the major contributor t

  14. On the puzzling distribution of cholesterol in the plasma membrane.

    Science.gov (United States)

    Giang, H; Schick, M

    2016-09-01

    The distribution of cholesterol between the two leaves of the plasma membrane in mammalian cells presents a conundrum; given cholesterol's known affinity for sphingomyelin, which resides predominantly in the exoplasmic leaf, why is it that experiment finds a majority of the cholesterol in the cytoplasmic leaf? This article reviews a recently proposed solution to this puzzle. PMID:26724709

  15. Alcohol consumption stimulates early steps in reverse cholesterol transport

    NARCIS (Netherlands)

    Gaag, M.S. van der; Tol, A. van; Vermunt, S.H.F.; Scheek, L.M.; Schaafsma, G.; Hendriks, H.F.J.

    2001-01-01

    Alcohol consumption is associated with increased HDL cholesterol levels, which may indicate stimulated reverse cholesterol transport. The mechanism is, however, not known. The aim of this study was to evaluate the effects of alcohol consumption on the first two steps of the reverse cholesterol pathw

  16. Effects of Cholesterol-altering Pharmaceuticals on Cholesterol Metabolism, Steroidogenesis, and Gene Expression in the Fathead Minnow (Pimephales promelas)

    Science.gov (United States)

    Pharmaceuticals that target cholesterol biosynthesis and uptake are among the most widely prescribed drugs and have been detected in the aquatic environment. Fibrates are a class of pharmaceuticals that indirectly modulate cholesterol biosynthesis through effects on peroxisome pr...

  17. Immobilization of cholesterol esterase and cholesterol oxidase onto sol-gel films for application to cholesterol biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Suman [Central Mechanical Engineering Research Institute, G. Avenue, Durgapur 713209, West Bengal (India); Singhal, Rahul [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Malhotra, B.D. [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India)]. E-mail: bansi.malhotra@gmail.com

    2007-01-23

    Cholesterol oxidase (ChOx) and cholesterol esterase (ChEt) have been covalently immobilized onto tetraethylorthosilicate (TEOS) sol-gel films. The tetraethylorthosilicate sol-gel/ChEt/ChOx enzyme films thus prepared have been characterized using scanning electron microscopic (SEM), UV-vis spectroscopic, Fourier-transform-infrared (FTIR) spectroscopic and amperometric techniques, respectively. The results of photometric measurements carried out on tetraethylorthosilicate sol-gel/ChEt/ChOx reveal thermal stability up to 55 deg. C, response time as 180 s, linearity up to 780 mg dL{sup -1} (12 mM), shelf life of 1 month, detection limit of 12 mg dL{sup -1} and sensitivity as 5.4 x 10{sup -5} Abs. mg{sup -1} dL{sup -1}.

  18. Understanding Cholesterol and Heart Health | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: High Cholesterol Understanding Cholesterol and Heart Health Past Issues / Summer 2012 Table ... both types of lipoproteins is important. High Blood Cholesterol and Triglycerides High blood cholesterol is a condition ...

  19. Effect of testosterone deficiency on cholesterol metabolism in pigs fed a high-fat and high-cholesterol diet

    OpenAIRE

    Cai, Zhaowei; Xi, Haitao; Pan, Yongming; Jiang, Xiaoling; Chen, Liang; Cai, Yueqin; Zhu, Keyan; Chen, Cheng; XU, XIAOPING; Chen, Minli

    2015-01-01

    Background Testosterone deficiency is associated with increased serum cholesterol levels. However, how testosterone deficiency precisely affects cholesterol metabolism remains unclear. Therefore, in the current study, we examined the effect of testosterone deficiency on cholesterol metabolism and liver gene expression in pigs fed a high-fat and high-cholesterol (HFC) diet. Methods Sexually mature male miniature pigs (6–7 months old) were randomly divided into 3 groups as follows: intact male ...

  20. Accessibility of Cholesterol in Endoplasmic Reticulum Membranes and Activation of SREBP-2 Switch Abruptly at a Common Cholesterol Threshold

    OpenAIRE

    Sokolov, Anna; Radhakrishnan, Arun

    2010-01-01

    Recent studies have shown that cooperative interactions in endoplasmic reticulum (ER) membranes between Scap, cholesterol, and Insig result in switch-like control over activation of SREBP-2 transcription factors. This allows cells to rapidly adjust rates of cholesterol synthesis and uptake in response to even slight deviations from physiological set-point levels, thereby ensuring cholesterol homeostasis. In the present study we directly probe for the accessibility of cholesterol in purified E...

  1. Image compression using constrained relaxation

    Science.gov (United States)

    He, Zhihai

    2007-01-01

    In this work, we develop a new data representation framework, called constrained relaxation for image compression. Our basic observation is that an image is not a random 2-D array of pixels. They have to satisfy a set of imaging constraints so as to form a natural image. Therefore, one of the major tasks in image representation and coding is to efficiently encode these imaging constraints. The proposed data representation and image compression method not only achieves more efficient data compression than the state-of-the-art H.264 Intra frame coding, but also provides much more resilience to wireless transmission errors with an internal error-correction capability.

  2. Constraining Lorentz violation with cosmology.

    Science.gov (United States)

    Zuntz, J A; Ferreira, P G; Zlosnik, T G

    2008-12-31

    The Einstein-aether theory provides a simple, dynamical mechanism for breaking Lorentz invariance. It does so within a generally covariant context and may emerge from quantum effects in more fundamental theories. The theory leads to a preferred frame and can have distinct experimental signatures. In this Letter, we perform a comprehensive study of the cosmological effects of the Einstein-aether theory and use observational data to constrain it. Allied to previously determined consistency and experimental constraints, we find that an Einstein-aether universe can fit experimental data over a wide range of its parameter space, but requires a specific rescaling of the other cosmological densities. PMID:19113765

  3. Fibroblast cholesterol efflux to plasma from metabolic syndrome subjects is not defective despite low high-density lipoprotein cholesterol

    NARCIS (Netherlands)

    R.P.F. Dullaart (Robin); A. Groen (Albert); G.M. Dallinga-Thie (Geesje); R. de Vries (Rindert); W. Sluiter (Wim); A. van Tol (Arie)

    2008-01-01

    textabstractObjective: We tested whether in metabolic syndrome (MetS) subjects the ability of plasma to stimulate cellular cholesterol efflux, an early step in the anti-atherogenic reverse cholesterol transport pathway, is maintained despite low high-density lipoprotein (HDL) cholesterol. Design: In

  4. Compositions constrained by graph Laplacian minors

    CERN Document Server

    Braun, Benjamin; Harrison, Ashley; McKim, Jessica; Noll, Jenna; Taylor, Clifford

    2012-01-01

    Motivated by examples of symmetrically constrained compositions, super convex partitions, and super convex compositions, we initiate the study of partitions and compositions constrained by graph Laplacian minors. We provide a complete description of the multivariate generating functions for such compositions in the case of trees. We answer a question due to Corteel, Savage, and Wilf regarding super convex compositions, which we describe as compositions constrained by Laplacian minors for cycles; we extend this solution to the study of compositions constrained by Laplacian minors of leafed cycles. Connections are established and conjectured between compositions constrained by Laplacian minors of leafed cycles of prime length and algebraic/combinatorial properties of reflexive simplices.

  5. Increased Synthesis of Anti-Tuberculous Glycolipid Immunoglobulin G (IgG) and IgA with Cavity Formation in Patients with Pulmonary Tuberculosis▿

    OpenAIRE

    Mizusawa, Masako; Kawamura, Mizuoho; Takamori, Mikio; Kashiyama, Tetsuya; Fujita, Akira; Usuzawa, Motoki; Saitoh, Hiroki; Ashino, Yugo; Yano, Ikuya; Hattori, Toshio

    2008-01-01

    Tuberculous glycolipid (TBGL) antigen is a cell wall component of Mycobacterium tuberculosis and has been used for the serodiagnosis of tuberculosis. We investigated correlations between the levels of anti-TBGL antibodies and a variety of laboratory markers that are potentially influenced by tuberculous infection. Comparisons between patients with cavitary lesions and those without cavitary lesions were also made in order to determine the mechanism underlying the immune response to TBGL. Bloo...

  6. Analysis of NMR spectra of sugar chains of glycolipids by multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy

    International Nuclear Information System (INIS)

    The authors applied multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy to globoside, a glycolipid purified from human red blood cells. The subspectra corresponding to individual sugar components were extracted even from overlapping proton resonances by taking the cross sections of 2D spectra parallel to the F2 axis at anomeric proton resonances, so that unambiguous assignments of sugar proton resonances were accomplished. (Auth.)

  7. Quantum Annealing for Constrained Optimization

    Science.gov (United States)

    Hen, Itay; Spedalieri, Federico M.

    2016-03-01

    Recent advances in quantum technology have led to the development and manufacturing of experimental programmable quantum annealers that promise to solve certain combinatorial optimization problems of practical relevance faster than their classical analogues. The applicability of such devices for many theoretical and real-world optimization problems, which are often constrained, is severely limited by the sparse, rigid layout of the devices' quantum bits. Traditionally, constraints are addressed by the addition of penalty terms to the Hamiltonian of the problem, which, in turn, requires prohibitively increasing physical resources while also restricting the dynamical range of the interactions. Here, we propose a method for encoding constrained optimization problems on quantum annealers that eliminates the need for penalty terms and thereby reduces the number of required couplers and removes the need for minor embedding, greatly reducing the number of required physical qubits. We argue the advantages of the proposed technique and illustrate its effectiveness. We conclude by discussing the experimental feasibility of the suggested method as well as its potential to appreciably reduce the resource requirements for implementing optimization problems on quantum annealers and its significance in the field of quantum computing.

  8. Is the FXR the fix for cholesterol gallstone disease?

    Science.gov (United States)

    Juran, Brian D; Lazaridis, Konstantinos N

    2005-07-01

    Cholesterol gallstone disease is characterized by several events, including cholesterol precipitation in bile, increased bile salt hydrophobicity and gallbladder inflammation. Here, we describe the same phenotype in mice lacking the bile acid receptor, FXR. Furthermore, in susceptible wild-type mice that recapitulate human cholesterol gallstone disease, treatment with a synthetic FXR agonist prevented sequelae of the disease. These effects were mediated by FXR-dependent increases in biliary bile salt and phospholipid concentrations, which restored cholesterol solubility and thereby prevented gallstone formation. Taken together, these results indicate that FXR is a promising therapeutic target for treating or preventing cholesterol gallstone disease. PMID:15962294

  9. [HDL cholesterol as a sensitive diagnostic parameter in malaria].

    Science.gov (United States)

    Kittl, E M; Diridl, G; Lenhart, V; Neuwald, C; Tomasits, J; Pichler, H; Bauer, K

    1992-01-01

    In patients with malaria the lipid parameters triglycerides, cholesterol, and HDL-cholesterol were determined routinely. At the time of admission hypertriglyceridemia, hypocholesterolemia, and an extreme decrease in HDL-cholesterol were found. This dyslipoproteinemia was present in cases of falciparum malaria, as well as in cases of benign tertian malaria. The extent of HDL-cholesterol decrease showed no correlation to the severity of the clinical course of disease. HDL-cholesterol has proven to be an independent diagnostic laboratory finding in cases of suspected malarial infection. This parameter displays high diagnostic sensitivity, but no specificity for malaria. PMID:1546481

  10. Biochemical and Bioimaging Evidence of Cholesterol in Acquired Cholesteatoma

    DEFF Research Database (Denmark)

    Thorsted, Bjarne; Bloksgaard, Maria; Groza, Alexandra;

    2016-01-01

    results show that the total lipid content of the cholesteatoma matrix is similar to that of stratum corneum from skin and that the cholesteatoma matrix unquestionably contains cholesterol. The cholesterol content in the cholesteatoma matrix is increased by over 30% (w/w dry weight) compared to the control....... The cholesterol sulfate content is below 1% of the total lipids in both the cholesteatoma and the control. Cholesterol ester was reduced by over 30% when compared to the control. CONCLUSIONS: The content of cholesterol in the cholesteatoma matrix is significantly different from that in stratum corneum...

  11. Common Force Field Thermodynamics of Cholesterol

    OpenAIRE

    Francesco Giangreco; Eiji Yamamoto; Yoshinori Hirano; Milan Hodoscek; Volker Knecht; Matteo di Giosia; Matteo Calvaresi; Francesco Zerbetto; Kenji Yasuoka; Tetsu Narumi; Masato Yasui; Siegfried Höfinger

    2013-01-01

    Four different force fields are examined for dynamic characteristics using cholesterol as a case study. The extent to which various types of internal degrees of freedom become thermodynamically relevant is evaluated by means of principal component analysis. More complex degrees of freedom (angle bending, dihedral rotations) show a trend towards force field independence. Moreover, charge assignments for membrane-embedded compounds are revealed to be critical with significant impact on biologic...

  12. Cholesterol crystal embolisation to the alimentary tract.

    OpenAIRE

    Moolenaar, W; Lamers, C B

    1996-01-01

    The features of cholesterol crystal embolisation (CCE) to the alimentary tract were studied by retrospective analysis of the clinical and pathological data of 96 patients (70 men, 26 women, mean age 73.8 (58-95) years) with this diagnosis in the Dutch national pathology information system (Pathologisch Anatomisch Landelijk Geautomatiseerd Archief (PALGA)) from 1973-92. In the 96 patients, 130 CCE sites were found throughout the alimentary tract, mostly in the colon (42.3%). Most patients had ...

  13. Potent and selective mediators of cholesterol efflux

    Energy Technology Data Exchange (ETDEWEB)

    Bielicki, John K; Johansson, Jan

    2015-03-24

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  14. Individual variation in serum cholesterol levels.

    OpenAIRE

    Hegsted, D. M.; Nicolosi, R J

    1987-01-01

    The intraindividual variances in serum/plasma cholesterol levels from a variety of sources have been examined. It is apparent that these are very substantial with mean coefficients of variation usually between 5% and 10%, even when the diet is controlled in metabolic studies. Some subjects show extreme variability from one blood sample to the next. Thus, it is very difficult to assess the degree of risk of individuals according to the guidelines provided by the Consensus Conference on lowerin...

  15. The Triglyceride-to-HDL Cholesterol Ratio

    OpenAIRE

    Giannini, Cosimo; Santoro, Nicola; Caprio, Sonia; Kim, Grace; Lartaud, Derek; Shaw, Melissa; Pierpont, Bridget; Weiss, Ram

    2011-01-01

    OBJECTIVE We evaluated whether the triglyceride-to-HDL cholesterol (TG/HDL-C) ratio is associated with insulin resistance (IR) in a large multiethnic cohort of obese youths. RESEARCH DESIGN AND METHODS Obese youths (1,452) had an oral glucose tolerance test and a fasting lipid profile. Insulin sensitivity was estimated using the whole body insulin sensitivity index (WBISI) and homeostasis model assessment (HOMA)-IR and evaluated, in a subgroup of 146 obese youths, by the hyperinsulinemic-eugl...

  16. HDL Cholesterol and Risk of Type 2 Diabetes

    DEFF Research Database (Denmark)

    Haase, Christiane L; Tybjærg-Hansen, Anne; Nordestgaard, Børge G;

    2015-01-01

    Observationally, low levels of HDL cholesterol are consistently associated with increased risk of type 2 diabetes. Therefore, plasma HDL cholesterol increasing has been suggested as a novel therapeutic option to reduce the risk of type 2 diabetes. Whether levels of HDL cholesterol are causally...... associated with type 2 diabetes is unknown. In a prospective study of the general population (n = 47,627), we tested whether HDL cholesterol-related genetic variants were associated with low HDL cholesterol levels and, in turn, with an increased risk of type 2 diabetes. HDL cholesterol-decreasing gene scores...... and allele numbers associated with up to -13 and -20% reductions in HDL cholesterol levels. The corresponding theoretically predicted hazard ratios for type 2 diabetes were 1.44 (95% CI 1.38-1.52) and 1.77 (1.61-1.95), whereas the genetic estimates were nonsignificant. Genetic risk ratios for type 2...

  17. Adrenal scanning with 131I-19-cholesterol

    International Nuclear Information System (INIS)

    The purpose of this paper is to describe our clinical experience of adrenal scanning with 131I-19-cholesterol and discuss its clinical usefulness. Adrenal scanning was performed for 21 patients with hypertension. One millicurie of 131I-19-cholesterol was injected intravenously and adrenal scannings were taken 6 to 11 days after injection with a rectilinear scanner or a gamma camera. No patient had an untoward reaction to the radiopharmaceutical. Confirmed diagnosis was obtained in 7 of 21 patients, i.e., 3 cases of primary aldosteronism, 1 idiopathic aldosteronism, 1 Cushing's syndrome and 2 cases of the essential hypertension. Among all of the primary aldosteronism and Cushing's syndrome, adrenal scanning gave clear evidence of concentration of radioactivity at the site of tumor. In the idiopathic aldosteronism of our study, uptake of radioactivity was brightly visible on the right, while uptake by the left gland was inhibited, so this case was diagnosed incorrectly as primary aldosteronism. The kidney scan with 203Hg-chlormerodrin obtained without moving the patient after an adrenal scan was very useful for getting information of anatomical site of the activity. The effective half-life was calculated as 1.83 days by means of sequential profile whole-body scannings, and the total-body absorbed radiation dose was estimated as 0.65 rad/mCi by using MIRD pamphlets. Our conclusion is that the adrenal scanning with 131I-19-cholesterol is very useful for localization of the functional adrenal cortical tumor. (author)

  18. Mitochondrial cholesterol: mechanisms of import and effects on mitochondrial function.

    Science.gov (United States)

    Martin, Laura A; Kennedy, Barry E; Karten, Barbara

    2016-04-01

    Mitochondria require cholesterol for biogenesis and membrane maintenance, and for the synthesis of steroids, oxysterols and hepatic bile acids. Multiple pathways mediate the transport of cholesterol from different subcellular pools to mitochondria. In steroidogenic cells, the steroidogenic acute regulatory protein (StAR) interacts with a mitochondrial protein complex to mediate cholesterol delivery to the inner mitochondrial membrane for conversion to pregnenolone. In non-steroidogenic cells, several members of a protein family defined by the presence of a StAR-related lipid transfer (START) domain play key roles in the delivery of cholesterol to mitochondrial membranes. Subdomains of the endoplasmic reticulum (ER), termed mitochondria-associated ER membranes (MAM), form membrane contact sites with mitochondria and may contribute to the transport of ER cholesterol to mitochondria, either independently or in conjunction with lipid-transfer proteins. Model systems of mitochondria enriched with cholesterol in vitro and mitochondria isolated from cells with (patho)physiological mitochondrial cholesterol accumulation clearly demonstrate that mitochondrial cholesterol levels affect mitochondrial function. Increased mitochondrial cholesterol levels have been observed in several diseases, including cancer, ischemia, steatohepatitis and neurodegenerative diseases, and influence disease pathology. Hence, a deeper understanding of the mechanisms maintaining mitochondrial cholesterol homeostasis may reveal additional targets for therapeutic intervention. Here we give a brief overview of mitochondrial cholesterol import in steroidogenic cells, and then focus on cholesterol trafficking pathways that deliver cholesterol to mitochondrial membranes in non-steroidogenic cells. We also briefly discuss the consequences of increased mitochondrial cholesterol levels on mitochondrial function and their potential role in disease pathology. PMID:25425472

  19. Preparation of cholesterol oxidase nanoparticles and their application in amperometric determination of cholesterol

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Sheetal; Rawal, Rachna; Sonia; Ramrati; Pundir, C. S., E-mail: pundircs@rediffmail.com [M. D. University, Department of Biochemistry (India)

    2013-09-15

    The nanoparticle (NP) aggregates of commercial cholesterol oxidase (ChOx) were prepared by desolvation method. The formation and characterization of ChOxNP aggregates were studied by transmission electron microscopy and scanning electron microscopy. NP aggregates were more stable, active and had a higher shelf life than that of free enzyme. An amperometric cholesterol biosensor was constructed by immobilizing ChOxNPs onto Au electrode. The biosensor showed optimum response within 8 s at pH 6.0 and 35 Degree-Sign C, when polarized at +0.27 V versus Ag/AgCl. The biosensor possesses high sensitivity and measures cholesterol concentrations as low as 1.56 mg/dl. The working linear range was 12.5-700 mg/dl for cholesterol. The biosensor was evaluated and employed for measurement of total cholesterol in human serum. The enzyme electrode lost 50 % of its initial activity during its regular use for 180 times over a period of 90 days when stored in 0.1 M sodium phosphate buffer, pH 7.0 at 4 Degree-Sign C.

  20. When cholesterol is not cholesterol: a note on the enzymatic determination of its concentration in model systems containing vegetable extracts

    Directory of Open Access Journals (Sweden)

    Pamplona Reinald

    2010-06-01

    Full Text Available Abstract Background Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts. Results By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on cholesterol partition. Evidenced interferences were analyzed by studying specific and unspecific inhibitors of cholesterol oxidase-peroxidase coupled reaction. Cholesterol was also quantified by LC/MS. We found a significant interference of diverse (cocoa and tea-derived extracts over this method. The interference was strongly dependent on model matrix: while as in phosphate buffered saline, the development of unspecific fluorescence was inhibitable by catalase (but not by heat denaturation, suggesting vegetable extract derived H2O2 production, in bile-containing model systems, this interference also comprised cholesterol-oxidase inhibition. Several strategies, such as cholesterol standard addition and use of suitable blanks containing vegetable extracts were tested. When those failed, the use of a mass-spectrometry based chromatographic assay allowed quantification of cholesterol in models of duodenal contents in the presence of vegetable extracts. Conclusions We propose that the use of cholesterol-oxidase and/or peroxidase based systems for cholesterol analyses in foodstuffs should be accurately monitored, as important interferences in all the components of the enzymatic chain were evident. The use of adequate controls, standard addition and finally, chromatographic analyses solve these issues.

  1. Constrained correlation dynamics of QCD

    International Nuclear Information System (INIS)

    The complete version of constrained correlation dynamics of SU(N) gauge theories in temporal gauge and canonical form has been formulated in three steps. (1) With the aid of generating-functional technique and in the framework of correlation dynamics, a closed set of equations of motion for correlation Green's functions have been established. (2) Gauge constraint conditions are analysed by means of Dirac theory. The algebraic representations of Gauss law and Ward identities are given. In accordance with the truncation approximations of correlation dynamics, the conserved Gauss law and Ward identities due to residual gauge invariance are shifted to initial value problems. (3) The equations of motion for multi-time correlation Green's functions have been transformed into those for equal-time correlation Green's functions. In two-body truncation approximation, a tractable set of equations of motion, Gauss law, and Ward identities are given explicitly

  2. Constrained Allocation Flux Balance Analysis

    CERN Document Server

    Mori, Matteo; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferr...

  3. Formal language constrained path problems

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.; Jacob, R.; Marathe, M.

    1997-07-08

    In many path finding problems arising in practice, certain patterns of edge/vertex labels in the labeled graph being traversed are allowed/preferred, while others are disallowed. Motivated by such applications as intermodal transportation planning, the authors investigate the complexity of finding feasible paths in a labeled network, where the mode choice for each traveler is specified by a formal language. The main contributions of this paper include the following: (1) the authors show that the problem of finding a shortest path between a source and destination for a traveler whose mode choice is specified as a context free language is solvable efficiently in polynomial time, when the mode choice is specified as a regular language they provide algorithms with improved space and time bounds; (2) in contrast, they show that the problem of finding simple paths between a source and a given destination is NP-hard, even when restricted to very simple regular expressions and/or very simple graphs; (3) for the class of treewidth bounded graphs, they show that (i) the problem of finding a regular language constrained simple path between source and a destination is solvable in polynomial time and (ii) the extension to finding context free language constrained simple paths is NP-complete. Several extensions of these results are presented in the context of finding shortest paths with additional constraints. These results significantly extend the results in [MW95]. As a corollary of the results, they obtain a polynomial time algorithm for the BEST k-SIMILAR PATH problem studied in [SJB97]. The previous best algorithm was given by [SJB97] and takes exponential time in the worst case.

  4. Isolation of basidiomycetous yeast Pseudozyma tsukubaensis and production of glycolipid biosurfactant, a diastereomer type of mannosylerythritol lipid-B.

    Science.gov (United States)

    Morita, Tomotake; Takashima, Masako; Fukuoka, Tokuma; Konishi, Masaaki; Imura, Tomohiro; Kitamoto, Dai

    2010-10-01

    The producers of glycolipid biosurfactant, mannosylerythritol lipid-B (MEL-B), were isolated from leaves of Perilla frutescens on Ibaraki in Japan. Four isolates, 1D9, 1D10, 1D11, and 1E5, were identified as basidiomycetous yeast Pseudozyma tsukubaensis by rDNA sequence and biochemical properties. The structure of MEL-B produced by these strains was analyzed by (1)H nuclear magnetic resonance and gas chromatography-mass spectrometry methods, and was determined to be the same as the diastereomer MEL-B produced by P. tsukubaensis NBRC 1940. Of these isolates, P. tsukubaensis 1E5 (JCM 16987) is capable of producing the largest amount of the diastereomer MEL-B from vegetable oils. In order to progress the diastereomer MEL-B production by strain 1E5, factors affecting the production, such as carbon and organic nutrient sources, were further examined. Olive oil and yeast extract were the best carbon and nutrient sources, respectively. Under the optimal conditions, a maximum yield, productivity, and yield coefficient of 73.1 g/L, 10.4 g L(-1) day(-1), and 43.5 g/g were achieved by feeding of olive oil in a 5-L jar-fermenter culture using strain 1E5. PMID:20652239

  5. A yeast glycolipid biosurfactant, mannosylerythritol lipid, shows high binding affinity towards lectins on a self-assembled monolayer system.

    Science.gov (United States)

    Konishi, Masaaki; Imura, Tomohiro; Fukuoka, Tokuma; Morita, Tomotake; Kitamoto, Dai

    2007-03-01

    Mannosylerythritol lipids (MEL), which are glycolipid biosurfactants secreted by the Pseudozyma yeasts, show not only excellent surface-active properties but also versatile biochemical actions including antitumor and cell-differentiation activities. In order to address the biochemical actions, interactions between MEL-A, the major component of MEL, and different lectins were investigated using the surface plasmon resonance spectroscopy. The monolayer of MEL-A showed high binding affinity to concanavalin A (ConA) and Maackia amurensis lectin-I (MAL-I). The observed affinity constants for ConA and MAL-I were estimated to be 9.48 +/- 1.31 x 10(6) and 3.13 +/- 0.274 x 10(6) M(-1), respectively; the value was comparable to that of Manalpha1-6(Manalpha1-3)Man, which is one of the most specific probe to ConA. Significantly, alpha-methyl-D-mannopyranoside (1 mM) exhibited no binding inhibition between MEL-A and ConA. MEL-A is thus likely to self-assemble to give a high affinity surface, where ConA binds to the hydrophilic headgroup in a different manner from that generally observed in lectin-saccharide interactions. The binding manner should be related with the biochemical actions of MEL toward mammalian cells via protein-carbohydrate interactions. PMID:17205206

  6. Ieodoglucomide C and Ieodoglycolipid, New Glycolipids from a Marine-Derived Bacterium Bacillus licheniformis 09IDYM23.

    Science.gov (United States)

    Tareq, Fakir Shahidullah; Lee, Hyi-Seung; Lee, Yeon-Ju; Lee, Jong Seok; Shin, Hee Jae

    2015-05-01

    Chemical examination of the ethyl acetate extract from the fermentation broth of the marine-derived bacterium Bacillus licheniformis resulted in the isolation of two new glycolipids, ieodoglucomide C (1) and ieodoglycolipid (2). The structural characterization of 1 and 2 was achieved by extensive spectroscopic evidence, including 2D NMR experiments. A combination of chemical derivatization techniques followed by NMR studies, LC-MS data analysis and a literature review was deployed for the establishment of the stereo-configurations of 1 and 2. Compounds 1 and 2 exhibited good antibiotic properties against Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa with MICs ranging from 0.01 to 0.05 μM. Furthermore, the antifungal activity of 1 and 2 was evaluated against plant pathogenic fungi Aspergillus niger, Rhizoctonia solani, Botrytis cinerea and Colletotrichum acutatum as well as the human pathogen Candida albicans. Compounds 1 and 2 inhibited the mycelial growth of these pathogens with MIC values of 0.03-0.05 μM, revealing that these compounds are good candidates for the development of new fungicides. PMID:25893812

  7. In vitro cholesterol uptake by Lactobacillus delbrueckii subsp. bulgaricus isolates

    Directory of Open Access Journals (Sweden)

    Małgorzata Ziarno

    2009-06-01

    Full Text Available Background. Some researchers have indicated that Lactobacillus delbrueckii subsp. bulgaricus may provide additional health benefits, reduce serum cholesterol level, for example. The aim of this study was to determine cholesterol uptake by Lb. delbrueckii subsp. bulgaricus commercial yoghurt starter isolates in artificial GIT fluids. Material and methods. Lb. delbrueckii subsp. bulgaricus isolates were cultured in MRS broth and in artificial GIT fluids contained cholesterol at initial concentration ca. 560 µg/mL, as well as in MRS broth with cholesterol addition. Results. All Lb. delbrueckii subsp. bulgaricus showed ability to uptake of cholesterol from MRS broth and artificial GIT fluids. The isolates incubated in artificial gastric fluid removed the minimal amounts of cholesterol in comparison to the same isolates incubated in MRS broth. Only two isolates removed significantly more cholesterol from MRS broth that from duodenal fluid. The amount of removed cholesterol from artificial duodenal fluid ranged from 20 µg/mL to 78 µg/mL. All Lb. delbrueckii subsp. bulgaricus isolates survived worse in artificial GIT fluids than in MRS broth. The viability of Lb. delbrueckii subsp. bulgaricus in GIT fluids depended on isolate. Conclusions. These results proved that Lb. delbrueckii subsp. bulgaricus shows ability to uptake cholesterol from MRS broth and artificial GIT fluids, and the degree of cholesterol uptake depends on isolate and incubation environment. The ability of Lb. delbrueckii subsp. bulgaricus to survive in GIT varies according to the isolates and incubation environment.

  8. Cholesterol: Its Regulation and Role in Central Nervous System Disorders

    Directory of Open Access Journals (Sweden)

    Matthias Orth

    2012-01-01

    Full Text Available Cholesterol is a major constituent of the human brain, and the brain is the most cholesterol-rich organ. Numerous lipoprotein receptors and apolipoproteins are expressed in the brain. Cholesterol is tightly regulated between the major brain cells and is essential for normal brain development. The metabolism of brain cholesterol differs markedly from that of other tissues. Brain cholesterol is primarily derived by de novo synthesis and the blood brain barrier prevents the uptake of lipoprotein cholesterol from the circulation. Defects in cholesterol metabolism lead to structural and functional central nervous system diseases such as Smith-Lemli-Opitz syndrome, Niemann-Pick type C disease, and Alzheimer’s disease. These diseases affect different metabolic pathways (cholesterol biosynthesis, lipid transport and lipoprotein assembly, apolipoproteins, lipoprotein receptors, and signaling molecules. We review the metabolic pathways of cholesterol in the CNS and its cell-specific and microdomain-specific interaction with other pathways such as the amyloid precursor protein and discuss potential treatment strategies as well as the effects of the widespread use of LDL cholesterol-lowering drugs on brain functions.

  9. Constraining Modified Gravity Theories With Cosmology

    OpenAIRE

    Martinelli, Matteo

    2012-01-01

    We study and constrain the Hu and Sawicki f(R) model using CMB and weak lensing forecasted data. We also use the same data to constrain extended theories of gravity and the subclass of f(R) theories using a general parameterization describing departures from General Relativity. Moreover we study and constrain also a Dark Coupling model where Dark Energy and Dark Matter are coupled toghether.

  10. Potassium-doped carbon nanotubes toward the direct electrochemistry of cholesterol oxidase and its application in highly sensitive cholesterol biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaorong [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Xu Jingjuan, E-mail: xujj@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Chen Hongyuan [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)

    2011-10-30

    We demonstrate herein a newly developed serum total cholesterol biosensor by using the direct electron transfer of cholesterol oxidase (ChOx), which is based on the immobilization of cholesterol oxidase and cholesterol esterase (ChEt) on potassium-doped multi-walled carbon nanotubes (KMWNTs) modified electrodes. The KMWNTs accelerate the electron transfer from electrode surface to the immobilized ChOx, achieving the direct electrochemistry of ChOx and maintaining its bioactivity. As a new platform in cholesterol analysis, the resulting electrode (ChOx/KMWNTs/GCE) exhibits a sensitive response to free cholesterol, with a linear range of 0.050-16.0 {mu}mol L{sup -1} and a detection limit of 5.0 nmol L{sup -1} (S/N = 3). Coimmobilization of ChEt and ChOx (ChEt/ChOx/KMWNTs/GCE) allows the determination of both free cholesterol and esterified cholesterol. The resulting biosensor shows the same linear range of 0.050-16.0 {mu}mol L{sup -1} for free cholesterol and cholesteryl oleate, with the detection limit of 10.0 and 12.0 nmol L{sup -1} (S/N = 3), respectively. The concentrations of total (free and esterified) cholesterol in human serum samples, determined by using the techniques developed in the present study, are in good agreement with those determined by the well-established techniques using the spectrophotometry.

  11. Effect of dietary Maitake (Grifola frondosa) mushrooms on plasma cholesterol and hepatic gene expression in cholesterol-fed mice.

    Science.gov (United States)

    Sato, Mayumi; Tokuji, Yoshihiko; Yoneyama, Shozo; Fujii-Akiyama, Kyoko; Kinoshita, Mikio; Chiji, Hideyuki; Ohnishi, Masao

    2013-01-01

    To investigate the effects of dietary Grifola frondosa on cholesterol, normal mice were fed a diet containing 1% cholesterol (HC group) or 1% cholesterol and 10% freeze-dried G. frondosa powder (HC+G group) for 4 weeks and hepatic and plasma lipid levels were compared with those of a cholesterol-free diet-fed mice (N group). Hepatic total cholesterol (TC), triacylglycerol contents were considerably increased and plasma TC / phospholipid (PL) was also increased significantly in the HC group compared with the N group. However, plasma TC content decreased in the HC+G group compared with the HC group. To characterize the mechanisms responsible for lowered plasma cholesterol in G. frondosa-supplemented mice, hepatic gene expression was profiled using DNA microarray and gene ontology. Genome analyses revealed that de novo cholesterol synthesis genes were suppressed following cholesterol intake. However, expression of bile acid biosynthesis and low-density lipoprotein receptor genes showed little change. Scarb1, Abcg5, and Abcg8, involved in cholesterol transport and excretion, were slightly upregulated in the HC+G group compared with the HC group. These data indicate the plasma cholesterol-lowering effect of G. frondosa. Moreover, fatty acid (FA) β-oxidation was promoted via adipocytokine signaling pathways, and Saa, encodes serum amyloid A related to arteriosclerosis, was suppressed in the HC+G group. PMID:24292357

  12. Preparation of intravenous cholesterol tracer using current good manufacturing practices.

    Science.gov (United States)

    Lin, Xiaobo; Ma, Lina; Racette, Susan B; Swaney, William P; Ostlund, Richard E

    2015-12-01

    Studies of human reverse cholesterol transport require intravenous infusion of cholesterol tracers. Because insoluble lipids may pose risk and because it is desirable to have consistent doses of defined composition available over many months, we investigated the manufacture of cholesterol tracer under current good manufacturing practice (CGMP) conditions appropriate for phase 1 investigation. Cholesterol tracer was prepared by sterile admixture of unlabeled cholesterol or cholesterol-d7 in ethanol with 20% Intralipid(®). The resulting material was filtered through a 1.2 micron particulate filter, stored at 4°C, and tested at time 0, 1.5, 3, 6, and 9 months for sterility, pyrogenicity, autoxidation, and particle size and aggregation. The limiting factor for stability was a rise in thiobarbituric acid-reacting substances of 9.6-fold over 9 months (P manufacturing methods can be achieved in the academic setting and need to be considered for critical components of future metabolic studies. PMID:26416797

  13. Transport of circulating serum cholesterol by human renal cell carcinoma

    International Nuclear Information System (INIS)

    Clear cell renal cancer contains a large quantity of cholesterol ester (300-mg./gm. protein). To determine whether abnormalities in cholesterol transport could account for this sterol accumulation, the uptake, release, and imaging capabilities of intravenously injected 131I-6-iodomethyl-29-norcholesterol, a cholesterol analogue, were studied preoperatively in five patients with clear cell renal cancer. At surgery, samples of the liver, tumor, adrenal, and non-tumor kidney were obtained for analysis. 131I-sterol uptake by the tumor, when normalized for cholesterol content, was less than for adrenal, liver or kidney. In contrast, release of preloaded 131I-sterol from the human tumors was consistently slower than for normal kidney. The reduced release of free cholesterol from renal cancer cells may, in part, be responsible for the accumulation of cholesterol in human renal cancer

  14. Cholesterol monohydrate nucleation in ultrathin films on water

    DEFF Research Database (Denmark)

    Rapaport, H.; Kuzmenko, I.; Lafont, S.;

    2001-01-01

    The growth of a cholesterol crystalline phase, three molecular layers thick at the air-water interface, was monitored by grazing incidence x-ray diffraction and x-ray reflectivity. Upon compression, a cholesterol film transforms from a monolayer of trigonal symmetry and low crystallinity to a...... trilayer, composed of a highly crystalline bilayer in a rectangular lattice and a disordered top cholesterol layer. This system undergoes a phase transition into a crystalline trilayer incorporating ordered water between the hydroxyl groups of the top and middle sterol layers in an arrangement akin to the...... triclinic 3-D crystal structure of cholesterol . H(2)O. By comparison, the cholesterol derivative stigmasterol transforms, upon compression, directly into a crystalline trilayer in the rectangular lattice. These results may contribute to an understanding of the onset of cholesterol crystallization in...

  15. Pairing of cholesterol with oxidized phospholipid species in lipid bilayers

    DEFF Research Database (Denmark)

    Khandelia, Himanshu; Loubet, Bastien; Olzynska, Agnieszka;

    2014-01-01

    We claim that (1) cholesterol protects bilayers from disruption caused by lipid oxidation by sequestering conical shaped oxidized lipid species such as 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PZPC) away from phospholipid, because cholesterol and the oxidized lipid have complementary...... shapes and (2) mixtures of cholesterol and oxidized lipids can self-assemble into bilayers much like lysolipid–cholesterol mixtures. The evidence for bilayer protection comes from molecular dynamics (MD) simulations and dynamic light scattering (DLS) measurements. Unimodal size distributions of extruded...... vesicles (LUVETs) made up of a mixture of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and PZPC containing high amounts of PZPC are only obtained when cholesterol is present in high concentrations. In simulations, bilayers containing high amounts of PZPC become porous, unless cholesterol is also present...

  16. Alterations of serum cholesterol and serum lipoprotein in breast cancer of women

    OpenAIRE

    Hasija, Kiran; Bagga, Hardeep K.

    2005-01-01

    Fasting blood sample of 50 normal subjects (control) and 100 patients of breast cancer were investigated for serum total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, very low density lipoprotein, high density lipoprotein cholesterol:low density lipoprotein cholesterol ratio and total cholesterol:high density lipoprotein cholesterol ratio during breast cancer of women. Five cancer stages, types, age groups, parity and menopausal status were undertaken...

  17. Constrained Allocation Flux Balance Analysis

    Science.gov (United States)

    Mori, Matteo; Hwa, Terence; Martin, Olivier C.

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  18. Gyrification from constrained cortical expansion

    CERN Document Server

    Tallinen, Tuomas; Biggins, John S; Mahadevan, L

    2015-01-01

    The exterior of the mammalian brain - the cerebral cortex - has a conserved layered structure whose thickness varies little across species. However, selection pressures over evolutionary time scales have led to cortices that have a large surface area to volume ratio in some organisms, with the result that the brain is strongly convoluted into sulci and gyri. Here we show that the gyrification can arise as a nonlinear consequence of a simple mechanical instability driven by tangential expansion of the gray matter constrained by the white matter. A physical mimic of the process using a layered swelling gel captures the essence of the mechanism, and numerical simulations of the brain treated as a soft solid lead to the formation of cusped sulci and smooth gyri similar to those in the brain. The resulting gyrification patterns are a function of relative cortical expansion and relative thickness (compared with brain size), and are consistent with observations of a wide range of brains, ranging from smooth to highl...

  19. Percentage of Adults with High Cholesterol Whose LDL Cholesterol Levels Are Adequately Controlled

    Science.gov (United States)

    ... non-missing response to cholesterol questionnaire. Exclusion Criteria: Pregnant women. Estimates for 18-39 year olds were not ... for only one type of service, such as dental or vision care. Persons covered by ... and Prevention, National Center for Health Statistics from the National ...

  20. Melittin-Lipid Bilayer Interactions and the Role of Cholesterol

    OpenAIRE

    Wessman, Per; Strömstedt, Adam A; Malmsten, Martin; Edwards, Katarina

    2008-01-01

    The membrane-destabilizing effect of the peptide melittin on phosphatidylcholine membranes is modulated by the presence of cholesterol. This investigation shows that inclusion of 40 mol % cholesterol in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine or 1,2-dioleoyl-sn-glycero-3-phosphocholine liposomes reduces melittin's affinity for the membrane. It is significant that the presence of cholesterol does not increase the amount of membrane-associated melittin needed to cause maximum leakage f...

  1. Interaction of Melittin with Membrane Cholesterol: A Fluorescence Approach

    OpenAIRE

    Raghuraman, H.; Chattopadhyay, Amitabha

    2004-01-01

    We have monitored the organization and dynamics of the hemolytic peptide melittin in membranes containing cholesterol by utilizing the intrinsic fluorescence properties of its functionally important sole tryptophan residue and circular dichroism spectroscopy. The significance of this study is based on the fact that the natural target for melittin is the erythrocyte membrane, which contains high amounts of cholesterol. Our results show that the presence of cholesterol inhibits melittin-induced...

  2. In vitro cholesterol uptake by Lactobacillus delbrueckii subsp. bulgaricus isolates

    OpenAIRE

    Małgorzata Ziarno

    2009-01-01

    Background. Some researchers have indicated that Lactobacillus delbrueckii subsp. bulgaricus may provide additional health benefits, reduce serum cholesterol level, for example. The aim of this study was to determine cholesterol uptake by Lb. delbrueckii subsp. bulgaricus commercial yoghurt starter isolates in artificial GIT fluids. Material and methods. Lb. delbrueckii subsp. bulgaricus isolates were cultured in MRS broth and in artificial GIT fluids contained cholesterol at initial con...

  3. Reverse cholesterol transport: From classical view to new insights

    OpenAIRE

    Astrid E van der Velde

    2010-01-01

    Cholesterol is of vital importance for the human body. It is a constituent for most biological membranes, it is needed for the formation of bile salts, and it is the precursor for steroid hormones and vitamin D. However, the presence of excess cholesterol in cells, and in particular in macrophages in the arterial vessel wall, might be harmful. The accumulation of cholesterol in arteries can lead to atherosclerosis, and in turn, to other cardiovascular diseases. The route that is primarily tho...

  4. Studies on PCSK9 in the regulation of cholesterol metabolism

    OpenAIRE

    Persson, Lena

    2011-01-01

    Elevated levels of plasma cholesterol, mainly in low density lipoproteins (LDL), are a major risk factor for coronary heart disease. The level of plasma LDL cholesterol (LDL-C) is largely dependent on the number of hepatic LDL receptors (LDLRs). Increased number of LDLRs leads to higher uptake of LDL particles and lower concentration of plasma LDL-C. Proprotein convertase subtilisin Kexin Type 9 (PCSK9) is a novel key regulator in cholesterol metabolism. PCSK9 reduces the numbe...

  5. Cholesterol esterification during differentiation of mouse erythroleukemia (Friend) cells.

    Science.gov (United States)

    Mulas, Maria Franca; Mandas, Antonella; Abete, Claudia; Dessì, Sandra; Mocali, Alessandra; Paoletti, Francesco

    2011-08-31

    Cholesterol is an essential constituent of all mammalian cell membranes and its availability is therefore a prerequisite for cellular growth and other functions. Several lines of evidence are now indicating an association between alterations of cholesterol homeostasis and cell cycle progression. However, the role of cholesterol in cell differentiation is still largely unknown. To begin to address this issue, in this study we examined changes in cholesterol metabolism and in the mRNA levels of proteins involved in cholesterol import and esterification (multi-drug resistance, MDR-3) and acylCoA: cholesterol acyltransferase (ACAT) and cholesterol export (caveolin-1) in Friend virus-induced erythroleukemia cells (MELC), in the absence or in the presence of the chemical inducer of differentiation, hexamethylene bisacetamide (HMBA). FBS-stimulated growth of MELC was accompanied by an immediate elevation of cholesterol synthesis and cholesterol esterification, and by an increase in the levels of MDR-3 and ACAT mRNAs. A decrease in caveolin-1 expression was also observed. However, when MELC were treated with HMBA, the inhibition of DNA synthesis caused by HMBA treatment, was associated with a decrease in cholesterol esterification and in ACAT and MDR-3 mRNA levels and an increase in caveolin-1 mRNA. Detection of cytoplasmic neutral lipids by staining MELC with oil red O, a dye able to evidence CE but not FC, revealed that HMBA-treatment also reduced growth-stimulated accumulation of cholesterol ester to approximately the same extent as the ACAT inhibitor, SaH. Overall, these results indicate for the first time a role of cholesterol esterification and of some related genes in differentiation of erythroid cells. PMID:22184540

  6. A review on lecithin:cholesterol acyltransferase deficiency.

    Science.gov (United States)

    Saeedi, Ramesh; Li, Min; Frohlich, Jiri

    2015-05-01

    Lecithin cholesterol acyl transferase (LCAT) is a plasma enzyme which esterifies cholesterol, and plays a key role in the metabolism of high-density lipoprotein cholesterol (HDL-C). Genetic disorders of LCAT are associated with lipoprotein abnormalities including low levels of HDL-C and presence of lipoprotein X, and clinical features mainly corneal opacities, changes in erythrocyte morphology and renal failure. Recombinant LCAT is being developed for the treatment of patients with LCAT deficiency. PMID:25172171

  7. Cholesterol esterification during differentiation of mouse erythroleukemia (Friend) cells

    Science.gov (United States)

    Mulas, Maria Franca; Mandas, Antonella; Abete, Claudia; Dessì, Sandra; Mocali, Alessandra; Paoletti, Francesco

    2011-01-01

    Cholesterol is an essential constituent of all mammalian cell membranes and its availability is therefore a prerequisite for cellular growth and other functions. Several lines of evidence are now indicating an association between alterations of cholesterol homeostasis and cell cycle progression. However, the role of cholesterol in cell differentiation is still largely unknown. To begin to address this issue, in this study we examined changes in cholesterol metabolism and in the mRNA levels of proteins involved in cholesterol import and esterification (multi-drug resistance, MDR-3) and acylCoA: cholesterol acyltransferase (ACAT) and cholesterol export (caveolin-1) in Friend virus-induced erythroleukemia cells (MELC), in the absence or in the presence of the chemical inducer of differentiation, hexamethylene bisacetamide (HMBA). FBS-stimulated growth of MELC was accompanied by an immediate elevation of cholesterol synthesis and cholesterol esterification, and by an increase in the levels of MDR-3 and ACAT mRNAs. A decrease in caveolin-1 expression was also observed. However, when MELC were treated with HMBA, the inhibition of DNA synthesis caused by HMBA treatment, was associated with a decrease in cholesterol esterification and in ACAT and MDR-3 mRNA levels and an increase in caveolin-1 mRNA. Detection of cytoplasmic neutral lipids by staining MELC with oil red O, a dye able to evidence CE but not FC, revealed that HMBA-treatment also reduced growth-stimulated accumulation of cholesterol ester to approximately the same extent as the ACAT inhibitor, SaH. Overall, these results indicate for the first time a role of cholesterol esterification and of some related genes in differentiation of erythroid cells. PMID:22184540

  8. Cholesterol esterification during differentiation of mouse erythroleukemia (Friend cells

    Directory of Open Access Journals (Sweden)

    Maria Franca Mulas

    2011-10-01

    Full Text Available Cholesterol is an essential constituent of all mammalian cell membranes, and its availability is therefore a prerequisite for cellular growth and other functions. Several lines of evidence are now indicating an association between alterations of cholesterol homeostasis and cell cycle progression. However, the role of cholesterol in cell differentiation is still largely unknown. To begin to address this issue, in this study we examined changes in cholesterol metabolism and in the mRNA levels of proteins involved in cholesterol import and esterification (multi-drug resistance, MDR-3 and acylCoA:cholesterol acyltransferase (ACAT and cholesterol export (caveolin-1 in Friend virus-induced erythroleukemia cells (MELC, in the absence or in the presence of the chemical inducer of differentiation, hexamethylene bisacetamide (HMBA. FBS-stimulated growth of MELC was accompanied by an immediate elevation of cholesterol synthesis and cholesterol esterification, and by an increase in the levels of MDR-3 and ACAT mRNAs. A decrease in caveolin-1 expression was also observed. However, when MELC were treated with HMBA, the inhibition of DNA synthesis caused by HMBA treatment, was associated with a decrease in cholesterol esterification and in ACAT and MDR-3 mRNA levels and an increase in caveolin-1 mRNA. Detection of cytoplasmic neutral lipids by staining MELC with oil red O, a dye able to evidence CE but not FC, revealed that HMBA-treatment also reduced growth-stimulated accumulation of cholesterol ester to approximately the same extent as the ACAT inhibitor, SaH. Overall, these results indicate for the first time a role of cholesterol esterification and of some related genes in differentiation of erythroid cells.

  9. Interaction of G protein coupled receptors and cholesterol.

    Science.gov (United States)

    Gimpl, Gerald

    2016-09-01

    G protein coupled receptors (GPCRs) form the largest receptor superfamily in eukaryotic cells. Owing to their seven transmembrane helices, large parts of these proteins are embedded in the cholesterol-rich plasma membrane bilayer. Thus, GPCRs are always in proximity to cholesterol. Some of them are functionally dependent on the specific presence of cholesterol. Over the last years, enormous progress on receptor structures has been achieved. While lipophilic ligands other than cholesterol have been shown to bind either inside the helix bundle or at the receptor-lipid interface, the binding site of cholesterol was either a single transmembrane helix or a groove between two or more transmembrane helices. A clear preference for one of the two membrane leaflets has not been observed. Not surprisingly, many hydrophobic residues (primarily leucine and isoleucine) were found to be involved in cholesterol binding. In most cases, the rough β-face of cholesterol contacted the transmembrane helix bundle rather than the surrounding lipid matrix. The polar hydroxy group of cholesterol was localized near the water-membrane interface with potential hydrogen bonding to residues in receptor loop regions. Although a canonical motif, designated as CCM site, was detected as a specific cholesterol binding site in case of the β2AR, this site was not found to be occupied by cholesterol in other GPCRs possessing the same motif. Cholesterol-receptor interactions can increase the compactness of the receptor structure and are able to enhance the conformational stability towards active or inactive receptor states. Overall, all current data suggest a high plasticity of cholesterol interaction sites in GPCRs. PMID:27108066

  10. CHOLESTEROL OXIDATION PRODUCTS IN MILK AND MILK PRODUCTS

    Directory of Open Access Journals (Sweden)

    A. Kemal SEÇKİN

    2004-02-01

    Full Text Available Cholesterol oxidation products (COPs are occurred by heat and light factors during processing, improper packaging and storage conditions. COPs are mutagenic, carcinogenity, cytotoxic, angiotoxic and damage to cell membrane and effect biosynthesis cholesterol in the metabolism . So, COPs have potential risk for public health. Also, in milk and milk products that have high cholesterol COPs can be also formed during processing and storage. Therefore it is necessary that measurements must be taken and standards must be in dairy about COPs.

  11. Cholesterol assimilation by Lactobacillus probiotic bacteria: an in vitro investigation.

    Science.gov (United States)

    Tomaro-Duchesneau, Catherine; Jones, Mitchell L; Shah, Divya; Jain, Poonam; Saha, Shyamali; Prakash, Satya

    2014-01-01

    Excess cholesterol is associated with cardiovascular diseases (CVD), an important cause of mortality worldwide. Current CVD therapeutic measures, lifestyle and dietary interventions, and pharmaceutical agents for regulating cholesterol levels are inadequate. Probiotic bacteria have demonstrated potential to lower cholesterol levels by different mechanisms, including bile salt hydrolase activity, production of compounds that inhibit enzymes such as 3-hydroxy-3-methylglutaryl coenzyme A, and cholesterol assimilation. This work investigates 11 Lactobacillus strains for cholesterol assimilation. Probiotic strains for investigation were selected from the literature: Lactobacillus reuteri NCIMB 11951, L. reuteri NCIMB 701359, L. reuteri NCIMB 702655, L. reuteri NCIMB 701089, L. reuteri NCIMB 702656, Lactobacillus fermentum NCIMB 5221, L. fermentum NCIMB 8829, L. fermentum NCIMB 2797, Lactobacillus rhamnosus ATCC 53103 GG, Lactobacillus acidophilus ATCC 314, and Lactobacillus plantarum ATCC 14917. Cholesterol assimilation was investigated in culture media and under simulated intestinal conditions. The best cholesterol assimilator was L. plantarum ATCC 14917 (15.18±0.55 mg/10(10) cfu) in MRS broth. L. reuteri NCIMB 701089 assimilated over 67% (2254.70±63.33 mg/10(10) cfu) of cholesterol, the most of all the strains, under intestinal conditions. This work demonstrates that probiotic bacteria can assimilate cholesterol under intestinal conditions, with L. reuteri NCIMB 701089 showing great potential as a CVD therapeutic. PMID:25295259

  12. Cholesterol Assimilation by Lactobacillus Probiotic Bacteria: An In Vitro Investigation

    Directory of Open Access Journals (Sweden)

    Catherine Tomaro-Duchesneau

    2014-01-01

    Full Text Available Excess cholesterol is associated with cardiovascular diseases (CVD, an important cause of mortality worldwide. Current CVD therapeutic measures, lifestyle and dietary interventions, and pharmaceutical agents for regulating cholesterol levels are inadequate. Probiotic bacteria have demonstrated potential to lower cholesterol levels by different mechanisms, including bile salt hydrolase activity, production of compounds that inhibit enzymes such as 3-hydroxy-3-methylglutaryl coenzyme A, and cholesterol assimilation. This work investigates 11 Lactobacillus strains for cholesterol assimilation. Probiotic strains for investigation were selected from the literature: Lactobacillus reuteri NCIMB 11951, L. reuteri NCIMB 701359, L. reuteri NCIMB 702655, L. reuteri NCIMB 701089, L. reuteri NCIMB 702656, Lactobacillus fermentum NCIMB 5221, L. fermentum NCIMB 8829, L. fermentum NCIMB 2797, Lactobacillus rhamnosus ATCC 53103 GG, Lactobacillus acidophilus ATCC 314, and Lactobacillus plantarum ATCC 14917. Cholesterol assimilation was investigated in culture media and under simulated intestinal conditions. The best cholesterol assimilator was L. plantarum ATCC 14917 (15.18 ± 0.55 mg/1010 cfu in MRS broth. L. reuteri NCIMB 701089 assimilated over 67% (2254.70 ± 63.33 mg/1010 cfu of cholesterol, the most of all the strains, under intestinal conditions. This work demonstrates that probiotic bacteria can assimilate cholesterol under intestinal conditions, with L. reuteri NCIMB 701089 showing great potential as a CVD therapeutic.

  13. New horizons for cholesterol ester transfer protein inhibitors.

    Science.gov (United States)

    Schwartz, Gregory G

    2012-02-01

    High-density lipoprotein (HDL) cholesterol levels bear an inverse relationship to cardiovascular risk. To date, however, no intervention specifically targeting HDL has been demonstrated to reduce cardiovascular risk. Cholesterol ester transfer protein (CETP) mediates transfer of cholesterol ester from HDL to apolipoprotein B-containing particles. Most, but not all observational cohort studies indicate that genetic polymorphisms of CETP associated with reduced activity and higher HDL cholesterol levels are also associated with reduced cardiovascular risk. Some, but not all studies indicate that CETP inhibition in rabbits retards atherosclerosis, whereas transgenic CETP expression in mice promotes atherosclerosis. Torcetrapib, the first CETP inhibitor to reach phase III clinical development, was abandoned due to excess mortality associated with increases in aldosterone and blood pressure. Two other CETP inhibitors have entered phase III clinical development. Anacetrapib is a potent inhibitor of CETP that produces very large increases in HDL cholesterol and large reductions in low-density lipoprotein (LDL) cholesterol, beyond those achieved with statins. Dalcetrapib is a less potent CETP inhibitor that produces smaller increases in HDL cholesterol with minimal effect on LDL cholesterol. Both agents appear to allow efflux of cholesterol from macrophages to HDL in vitro, and neither agent affects blood pressure or aldosterone in vivo. Two large cardiovascular outcomes trials, one with anacetrapib and one with dalcetrapib, should provide a conclusive test of the hypothesis that inhibition of CETP decreases cardiovascular risk. PMID:22083134

  14. Reconstitution of Cholesterol-Dependent Vaginolysin into Tethered Phospholipid Bilayers

    DEFF Research Database (Denmark)

    Budvytyte, Rima; Pleckaityte, M.; Zvirbliene, A.;

    2013-01-01

    Functional reconstitution of the cholesterol-dependent cytolysin vaginolysin (VLY) from Gardnerella vaginalis into artificial tethered bilayer membranes (tBLMs) has been accomplished. The reconstitution of VLY was followed in real-time by electrochemical impedance spectroscopy (EIS). Changes of the...... EIS parameters of the tBLMs upon exposure to VLY solutions were consistent with the formation of water-filled pores in the membranes. It was found that reconstitution of VLY is a strictly cholesterol-dependent, irreversible process. At a constant cholesterol concentration reconstitution of VLY...... platform for the detection of the activity of VLY and possibly other cholesterol-dependent cytolysins....

  15. Determination of cholesterol in human biliary calculus by TLC scanning

    Institute of Scientific and Technical Information of China (English)

    Yin Kang Yang; Kai Xiong Qiu; Yu Zhu Zhan; Er Yi Zhan; Hai Ming Yang; Ping Zheng

    2000-01-01

    AIM To study the physico-chemical properties of biliary calculus and the relationship between the calculusformation and the phase change of liquid crystal, providing the best evidence for the biliary calculusprevention and treatment.METHODS The cholesterol contents in thirty one cases of biliary calculus in Kunming were determined bydouble-wave-length TLC scanning with high efficiency silica gel films.RESULTS Under magnifiers, the granular biliary calculus from 31 patients were classified according totheir section structures and colours, as cholesterol cholelith, 25 cases; bilirubin cholelith, 4 cases andcompound cholelith, 2 cases. By TLC scanning, it was found that the content of cholesterol in human biliarycalculus was 71%- 100%, about 80% cholesterol bilestones whose cholesterol content was more than 90%being pure cholesterol bilestones.CONCLUSION Cholesterol bilestone is the main human biliary calculus in Kunming, which was inaccordance with X-ray analysis. Compared with the related reports, it is proved that the proportion ofcholesterol bilestones to biliary calculus is increasing because of the improved life standard and the decreaseof bilirubin bilestones resulted from bile duct ascariasis or bacteria infection in China since 90s, and that theincrease of cholesterol in-take leads to the increase of cholesterol metabolism disorder

  16. Cholesterol granuloma of the petrous apex: CT diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Lo, W.W.M.; Solti-Bohman, L.G.; Brackmann, D.E.; Gruskin, P.

    1984-12-01

    Cholesterol granuloma of the petrous apex is a readily recognizable and treatable entity that is more common than previously realized. Cholesterol granuloma grows slowly in the petrous apex as a mass lesion until it produces hearing loss, tinnitus, vertigo, and facial twitching. Twelve cases of cholesterol granuloma of the petrous apex are illustrated; ten of these analyzed in detail, especially with respect to CT findings. A sharply and smoothly marginated expansile lesion in the petrous apex, isodense with plain and nonenhancing on CT, is in all probability a cholesterol granuloma. Preoperative recognition by CT is important for planning proper treatment.

  17. Late endosomal membranes rich in lysobisphosphatidic acid regulate cholesterol transport.

    Science.gov (United States)

    Kobayashi, T; Beuchat, M H; Lindsay, M; Frias, S; Palmiter, R D; Sakuraba, H; Parton, R G; Gruenberg, J

    1999-06-01

    The fate of free cholesterol released after endocytosis of low-density lipoproteins remains obscure. Here we report that late endosomes have a pivotal role in intracellular cholesterol transport. We find that in the genetic disease Niemann-Pick type C (NPC), and in drug-treated cells that mimic NPC, cholesterol accumulates in late endosomes and sorting of the lysosomal enzyme receptor is impaired. Our results show that the characteristic network of lysobisphosphatidic acid-rich membranes contained within multivesicular late endosomes regulates cholesterol transport, presumably by acting as a collection and distribution device. The results also suggest that similar endosomal defects accompany the anti-phospholipid syndrome and NPC. PMID:10559883

  18. Cholesterol epoxide is a direct-acting mutagen.

    OpenAIRE

    A. Sevanian; Peterson, A R

    1984-01-01

    A 24-hr treatment of V79 Chinese hamster lung fibroblasts with 12.4 microM cholesterol 5 alpha, 6 alpha-epoxide induced 8-azaguanine-resistant mutants at frequencies 4.6- to 11.8-fold higher than the spontaneous mutation rate. We show that cholesterol epoxide, which is produced by in vivo cholesterol oxidation, is a weak direct-acting mutagen. Cholesterol epoxide was found to be accumulated by cells and transformed to cholestane-3 beta, 5 alpha, 6 beta-triol, which was more toxic and a more p...

  19. High-density lipoprotein cholesterol: How High

    Directory of Open Access Journals (Sweden)

    G Rajagopal

    2012-01-01

    Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

  20. Specific Ion Effects in Cholesterol Monolayers

    Directory of Open Access Journals (Sweden)

    Teresa Del Castillo-Santaella

    2016-05-01

    Full Text Available The interaction of ions with interfaces and, in particular, the high specificity of these interactions to the particular ions considered, are central questions in the field of surface forces. Here we study the effect of different salts (NaI, NaCl, CaCl2 and MgCl2 on monolayers made of cholesterol molecules, both experimentally (surface area vs. lateral pressure isotherms measured by a Langmuir Film Balance and theoretically (molecular dynamics (MD all-atomic simulations. We found that surface isotherms depend, both quantitatively and qualitatively, on the nature of the ions by altering the shape and features of the isotherm. In line with the experiments, MD simulations show clear evidences of specific ionic effects and also provide molecular level details on ion specific interactions with cholesterol. More importantly, MD simulations show that the interaction of a particular ion with the surface depends strongly on its counterion, a feature ignored so far in most theories of specific ionic effects in surface forces.

  1. Crystallogeny fundamentals of the cholesterol gallstone

    Institute of Scientific and Technical Information of China (English)

    Wu Jie; Zhou Jianli; He Lijun; Qu Xingang; Gu Lin; Yang Haimin

    2007-01-01

    The nucleation mechanism and crystal growth process of the cholesterol gallstone are studied and a systematic theory expounded by crystallogeny is proposed. Normal feed and stone-forming feed were used to raise guinea pigs in the control and stone-causing groups respectively. The state and transformation of liquid crystal vesicles, the appearance of crystal nuclei, and the formation of microcrystal grains were observed under a polarizing microscope during the experimental period. It was found that the liquid crystal vesicles in the bile of the control group were small, scattered, and always existed as single forms, and no shaped gallstone crystals were formed.While in the stone-causing group, liquid crystal vesicles grew to larger ones, and then aggregated to form large liquid crystal cells. Solid crystal growth along the edge of these liquid crystal cells formed microcrystal grains. These demonstrated that bile liquid crystal vesicles form the basic nuclei of cholesterol gallstone. Heterogeneous nucleation is the common process in the formation of crystal nuclei and crystal growth.

  2. Screening Glycolipids Against Proteins in Vitro Using Picodiscs and Catch-and-Release Electrospray Ionization-Mass Spectrometry.

    Science.gov (United States)

    Li, Jun; Fan, Xuxin; Kitova, Elena N; Zou, Chunxia; Cairo, Christopher W; Eugenio, Luiz; Ng, Kenneth K S; Xiong, Zi Jian; Privé, Gilbert G; Klassen, John S

    2016-05-01

    This work describes the application of the catch-and-release electrospray ionization-mass spectrometry (CaR-ESI-MS) assay, implemented using picodiscs (complexes comprised of saposin A and lipids, PDs), to screen mixtures of glycolipids (GLs) against water-soluble proteins to detect specific interactions. To demonstrate the reliability of the method, seven gangliosides (GM1, GM2, GM3, GD1a, GD1b, GD2, and GT1b) were incorporated, either individually or as a mixture, into PDs and screened against two lectins: the B subunit homopentamer of cholera toxin (CTB5) and a subfragment of toxin A from Clostridium difficile (TcdA-A2). The CaR-ESI-MS results revealed that CTB5 binds to six of the gangliosides (GM1, GM2, GM3, GD1a, GD1b, and GT1b), while TcdA-A2 binds to five of them (GM1, GM2, GM3, GD1a, and GT1b). These findings are consistent with the measured binding specificities of these proteins for ganglioside oligosaccharides. Screening mixtures of lipids extracted from porcine brain and a human epithelial cell line against CTB5 revealed binding to multiple GM1 isoforms as well as to fucosyl-GM1, which is a known ligand. Finally, a comparison of the present results with data obtained with the CaR-ESI-MS assay implemented using nanodiscs (NDs) revealed that the PDs exhibited similar or superior performance to NDs for protein-GL binding measurements. PMID:27049760

  3. Novel glycolipid TLR2 ligands of the type Pam2Cys-α-Gal: synthesis and biological properties.

    Science.gov (United States)

    Thomann, Jean-Sébastien; Monneaux, Fanny; Creusat, Gaëlle; Spanedda, Maria Vittoria; Heurtault, Béatrice; Habermacher, Chloé; Schuber, Francis; Bourel-Bonnet, Line; Frisch, Benoît

    2012-05-01

    A more complete understanding of the mechanism of action of TLR agonists has fueled the investigation of new synthetic immunoadjuvants. In this context, we designed and synthesized glycolipids of the type Pam(2)Cys-α-Galactose as novel immunoadjuvants. Their synthesis required modifying a hydrophobic tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety, i.e. the minimal structure required for TLR2 agonist activity, by addition of a hydrophilic head, either an α-Galactosylpyranose or an α-Galactosylfuranose to gain respectively Pam(2)CGalp and Pam(2)CGalf. While preparing a carbohydrate building block, an unexpected stereoselectivity was observed during a halide ion-catalytic process on a protected galactofuranose: the alpha anomer was obtained with surprisingly high selectivity (α/β ratio>9) and with good isolated yield (51%). The TLR2 binding properties of Pam(2)CGalp and Pam(2)CGalf were then fully evaluated. Their efficiency in triggering the proliferation of BALB/c mouse splenocytes was also compared to that of Pam(2)CAG and Pam(3)CAG, two well-established ligands of TLRs. Moreover, the maturation state of murine dendritic cells previously incubated with either Pam(2)CGalp or Pam(2)CGalf was monitored by flow cytometry and compared to that induced by lipopolysaccharide. Pam(2)CGalp and Pam(2)CGalf were found to be equivalent TLR2 agonists, and induced splenocyte proliferation and DC maturation. With very similar activity, Pam(2)CGalp and Pam(2)CGalf were also 10-fold to 100-fold better than Pam(2)CAG and Pam(3)CAG at inducing B cell proliferation. This represents the first time a glucidic head has been added to the tBoc-[2,3-bispalmitoyloxy-(2R)-propyl]-R-cysteinyl moiety whilst maintaining the immunomodulating activity. This should greatly enrich the data available on Pam(2)C structure/activity relationships. PMID:22483966

  4. Kinetic studies on the interactions between glycolipid biosurfactant assembled monolayers and various classes of immunoglobulins using surface plasmon resonance.

    Science.gov (United States)

    Ito, Seya; Imura, Tomohiro; Fukuoka, Tokuma; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2007-08-01

    Kinetic studies on the interactions between self-assembled monolayers of mannosylerythritol lipids (MELs), which are glycolipid biosurfactants abundantly produced by microorganisms, and various classes of immunoglobulins including human IgG, IgA, and IgM were performed using surface plasmon resonance (SPR). The effect of the MEL structure on the binding behavior of HIgG was examined. Assembled monolayers of MEL-A having two acetyl groups on the headgroup gave a high affinity (K(d)=1.7x10(-6)M) toward HIgG, while those of MEL-B or MEL-C having only one acetyl group at C-6' or C-4' position gave little affinity. Our kinetic analysis revealed that the binding manner of HIgG, HIgA (K(d)=2.4x10(-7)M), and HIgM (K(d)=2.2x10(-7)M) to the assembled monolayers of MEL-A is not the monovalent mode but the bivalent mode, and both the first and second rate association constants (k(a1), k(a2)) increase with an increase in the number of antibody binding sites, while those for dissociation (k(d1), k(d2)) changed little. Moreover, we succeeded in directly observing great amounts of HIgG, HIgA, and HIgM bound to MEL-A monolayers using atomic force microscopy (AFM). Finally, we found that MEL-A assembled monolayer binds toward various IgG derived from mouse, pig, rabbit, horse, goat, rat, and bovine as well as human IgG (HIgG), and the only exception was sheep IgG. These results clearly demonstrate that MEL-A assembled monolayers would be useful as noble affinity ligand system for various immunoglobulins. PMID:17428643

  5. Packing density of glycolipid biosurfactant monolayers give a significant effect on their binding affinity toward immunoglobulin G.

    Science.gov (United States)

    Imura, Tomohiro; Masuda, Yuma; Ito, Seya; Worakitkanchanakul, Wannasiri; Morita, Tomotake; Fukuoka, Tokuma; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipid-A (MEL-A) is one of the most promising glycolipid biosurfactants, and abundantly produced by Pseudozyma yeasts. MEL-A gives not only excellent self-assembling properties but also a high binding affinity toward human immunoglobulin G (HIgG). In this study, three kinds of MEL-A were prepared from methyl myristate [MEL-A (m)], olive oil [MEL-A (o)], and soybean oil [MEL-A (s)], and the effect of interfacial properties of each MEL-A monolayer on the binding affinity toward HIgG was investigated using surface plasmon resonance (SPR) and the measurement of surface pressure (pi)-area (A) isotherms. Based on GC-MS analysis, the main fatty acids were C(8) and C(10) acids in all MEL-A, and the content of unsaturated fatty acids was 0% for MEL-A (m), 9.1% for MEL-A (o), 46.3% for MEL-A (s), respectively. Interestingly, the acid content significantly influenced on their binding affinity, and the monolayer of MEL-A (o) gave a higher binding affinity than that of MEL-A (m) and MEL-A (s). Moreover, the mixed MEL-A (o)/ MEL-A (s) monolayer prepared from 1/1 molar ratio, which comprised of 27.8% of unsaturated fatty acids, indicated the highest binding affinity. At the air/water interface, MEL-A (o) monolayer exhibited a phase transition at 13 degrees C from a liquid condensed monolayer to a liquid expanded monolayer, and the area per molecule significantly expanded above 13 degrees C, while the amount of HIgG bound to the liquid expanded monolayer was much higher than that bound to liquid condensed monolayer. The binding affinity of MEL-A toward HIgG is thus likely to closely relate to the monolayer packing density, and may be partly controlled by temperature. PMID:18622124

  6. Extracellular production of a glycolipid biosurfactant, mannosylerythritol lipid, by Candida sp. SY16 using fed-batch fermentation.

    Science.gov (United States)

    Kim, Hee-Sik; Jeon, Jong-Woon; Kim, Byung-Hyuk; Ahn, Chi-Yong; Oh, Hee-Mock; Yoon, Byung-Dae

    2006-04-01

    Candida sp. strain SY16 produces a glycolipid-type biosurfactant, mannosylerythritol lipid (MEL-SY16), which can reduce the surface tension of a culture broth from 72 to 30 dyne cm(-1) and highly emulsify hydrocarbons when cultured in soybean-oil-containing media. As such, laboratory-scale fermentation for MEL-SY16 production was performed using optimized conditions. In batch fermentation, MEL-SY16 was mainly produced during the stationary phase of growth, and the concentration of MEL-SY16 reached 37 g l(-1) after 200 h. The effect of pH control on the production of MEL-SY16 was also examined in batch fermentation. The highest production yield of MEL-SY16 was when the pH was controlled at 4.0, and the production was significantly improved compared to batch fermentation without pH control. In fed-batch fermentation, glucose and soybean oil (1:1, w/w) were used in combination as the initial carbon sources for cell growth, and soybean oil was used as the feeding carbon source during the MEL production phase. The feeding of soybean oil resulted in the disappearance of any foam and a sharp increase in the MEL production until 200 h, at which point the concentration of MEL-SY16 was 95 g l(-1). Among the investigated culture systems, the highest MEL-SY16 production and volumetric production rate were achieved with fed-batch fermentation. PMID:16133323

  7. Assessment of modes of action and efficacy of plasma cholesterol-lowering drugs : measurement of cholesterol absorption, cholesterol synthesis and bile acid synthesis and turnover using novel stable isotope techniques

    NARCIS (Netherlands)

    Stellaard, Frans; Kuipers, Folkert

    2005-01-01

    Several processes are involved in control of plasma cholesterol levels, e.g., intestinal cholesterol absorption, endogenous cholesterol synthesis and transport and bile acid synthesis. Adaptation of either of these processes allows the body to adapt to changes in dietary cholesterol intake. Disturba

  8. Cholesterol efflux via ATP-binding cassette transporter A1 (ABCA1) and cholesterol uptake via the LDL receptor influences cholesterol-induced impairment of beta cell function in mice

    NARCIS (Netherlands)

    Kruit, J. K.; Kremer, P. H. C.; Dai, L.; Tang, R.; Ruddle, P.; de Haan, W.; Brunham, L. R.; Verchere, C. B.; Hayden, M. R.

    2010-01-01

    Cellular cholesterol accumulation is an emerging mechanism for beta cell dysfunction in type 2 diabetes. Absence of the cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) results in increased islet cholesterol and impaired insulin secretion, indicating that impaired cholesterol effl

  9. Discovery of Pseudozyma rugulosa NBRC 10877 as a novel producer of the glycolipid biosurfactants, mannosylerythritol lipids, based on rDNA sequence.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2006-11-01

    The search for a novel producer of glycolipid biosurfactants, mannosylerythritol lipids (MEL) was undertaken based on the analysis of ribosomal DNA sequences on the yeast strains of the genus Pseudozyma. Pseudozyma rugulosa NBRC 10877 was found to produce a large amount of glycolipids from soybean oil. Fluorescence microscopic observation also demonstrated that the strain significantly accumulates polar lipids in the cells. The structure of the glycolipids produced by the strain was analyzed by (1)H and (13)C nuclear magnetic resonance and gas chromatography-mass spectrometry methods, and was determined to be the same as MEL produced by Pseudozyma antarctica, a well-known MEL producer. The major fatty acids of the present MEL consisted of C8 and C10 acids. Based on high performance liquid chromatography, the composition of the produced MEL was as follows: MEL-A (68%), MEL-B (12%), and MEL-C (20%). To enhance the production of MEL by the novel strain, factors affecting the production, such as carbon and nitrogen sources, were further examined. Soybean oil and sodium nitrate were the best carbon and nitrogen sources, respectively. The supplementation of a MEL precursor, such as erythritol, drastically enhanced the production yield from soybean oil at a rate of 70 to 90%. Under the optimal conditions in a shake culture, a maximum yield, productivity, and yield coefficient (on a weight basis to soybean oil supplied) of 142 g l(-1), 5.0 g l(-1) day(-1), and 0.5 g g(-1) were achieved by intermittent feeding of soybean oil and erythritol using the yeast. PMID:16733733

  10. The hedgehog receptor patched is involved in cholesterol transport.

    Directory of Open Access Journals (Sweden)

    Michel Bidet

    Full Text Available BACKGROUND: Sonic hedgehog (Shh signaling plays a crucial role in growth and patterning during embryonic development, and also in stem cell maintenance and tissue regeneration in adults. Aberrant Shh pathway activation is involved in the development of many tumors, and one of the most affected Shh signaling steps found in these tumors is the regulation of the signaling receptor Smoothened by the Shh receptor Patched. In the present work, we investigated Patched activity and the mechanism by which Patched inhibits Smoothened. METHODOLOGY/PRINCIPAL FINDINGS: Using the well-known Shh-responding cell line of mouse fibroblasts NIH 3T3, we first observed that enhancement of the intracellular cholesterol concentration induces Smoothened enrichment in the plasma membrane, which is a crucial step for the signaling activation. We found that binding of Shh protein to its receptor Patched, which involves Patched internalization, increases the intracellular concentration of cholesterol and decreases the efflux of a fluorescent cholesterol derivative (BODIPY-cholesterol from these cells. Treatment of fibroblasts with cyclopamine, an antagonist of Shh signaling, inhibits Patched expression and reduces BODIPY-cholesterol efflux, while treatment with the Shh pathway agonist SAG enhances Patched protein expression and BODIPY-cholesterol efflux. We also show that over-expression of human Patched in the yeast S. cerevisiae results in a significant boost of BODIPY-cholesterol efflux. Furthermore, we demonstrate that purified Patched binds to cholesterol, and that the interaction of Shh with Patched inhibits the binding of Patched to cholesterol. CONCLUSION/SIGNIFICANCE: Our results suggest that Patched may contribute to cholesterol efflux from cells, and to modulation of the intracellular cholesterol concentration. This activity is likely responsible for the inhibition of the enrichment of Smoothened in the plasma membrane, which is an important step in Shh pathway

  11. Direct observations of transition dynamics from macro- to micro-phase separation in asymmetric lipid bilayers induced by externally added glycolipids

    Science.gov (United States)

    Shimobayashi, Shunsuke F.; Ichikawa, Masatoshi; Taniguchi, Takashi

    2016-03-01

    We present the first direct observations of morphological transitions from macro- to micro-phase separation using micrometer-sized asymmetric lipid vesicles exposed to externally added glycolipids (GM1:monosialotetrahexosylganglioside). The transition occurs via an intermediate stripe morphology state. During the transition, monodisperse micro-domains emerge through repeated scission events of the stripe domains. Moreover, we numerically confirmed such transitions using a time-dependent Ginzburg-Landau model, which describes both the intramembrane phase separation and the bending elastic membrane. The experimental and simulation results are in quantitative agreement.

  12. Activation of human antigen-presenting cells by the mycobacterial cord factor and its glycolipid adjuvant analogue trehalose-6,6’-dibehenate

    OpenAIRE

    Ostrop, Jenny

    2015-01-01

    The mycobacterial cord factor trehalose-6,6’-dimycolate (TDM) is an abundant cell wall glycolipid of Mycobacterium tuberculosis and other mycobacteria. It causes inflammation and adjuvanticity, but it is also a major virulence factor of M. tuberculosis. Its synthetic analogue trehalose-6,6’-dibehenate (TDB) has robust adjuvant activity and induces a Th1/Th17 T cell response in animal models. The TDB-containing liposomal adjuvant formulation Caf01 has entered phase I clinical studies in humans...

  13. Constrained Deformable-Layer Tomography

    Science.gov (United States)

    Zhou, H.

    2006-12-01

    The improvement on traveltime tomography depends on improving data coverage and tomographic methodology. The data coverage depends on the spatial distribution of sources and stations, as well as the extent of lateral velocity variation that may alter the raypaths locally. A reliable tomographic image requires large enough ray hit count and wide enough angular range between traversing rays over the targeted anomalies. Recent years have witnessed the advancement of traveltime tomography in two aspects. One is the use of finite frequency kernels, and the other is the improvement on model parameterization, particularly that allows the use of a priori constraints. A new way of model parameterization is the deformable-layer tomography (DLT), which directly inverts for the geometry of velocity interfaces by varying the depths of grid points to achieve a best traveltime fit. In contrast, conventional grid or cell tomography seeks to determine velocity values of a mesh of fixed-in-space grids or cells. In this study, the DLT is used to map crustal P-wave velocities with first arrival data from local earthquakes and two LARSE active surveys in southern California. The DLT solutions along three profiles are constrained using known depth ranges of the Moho discontinuity at 21 sites from a previous receiver function study. The DLT solutions are generally well resolved according to restoration resolution tests. The patterns of 2D DLT models of different profiles match well at their intersection locations. In comparison with existing 3D cell tomography models in southern California, the new DLT models significantly improve the data fitness. In comparison with the multi-scale cell tomography conducted for the same data, while the data fitting levels of the DLT and the multi-scale cell tomography models are compatible, the DLT provides much higher vertical resolution and more realistic description of the undulation of velocity discontinuities. The constraints on the Moho depth

  14. Cholesterol Check (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-09-10

    High blood cholesterol is a risk factor for cardiovascular disease. This podcast discusses the importance of a healthy diet and regular cholesterol screening.  Created: 9/10/2015 by MMWR.   Date Released: 9/10/2015.

  15. CDC Vital Signs: High Blood Pressure and Cholesterol

    Science.gov (United States)

    ... 1.36 MB] Read the MMWR Science Clips High Blood Pressure and Cholesterol Out of Control Recommend on Facebook ... by County http://apps.nccd.cdc.gov/GISCVH2/ High Blood Pressure and High Cholesterol Among US Adults SOURCES: National ...

  16. Transport of cholesterol autoxidation products in rabbit lipoproteins

    International Nuclear Information System (INIS)

    Radiolabeled pure [4-14C] cholesterol was kept at 600C under air to autoxidize for 5 weeks, after which approximately 12% cholesterol oxidation products were formed. The mixture, suspended in gelatin, was given to rabbits by gastric gavage. Rabbits were killed 4, 24 and 48 h after treatment. Cholesterol and its autoxidation products were separated by thin-layer chromatography into 5 fractions and radioactivities of each fraction were measured. Percentages of each fraction of cholesterol oxidation products and cholesterol in the original mixture before administration and in the rabbit sera after administration were similar, suggesting that the rates of absorption of cholesterol oxidation products are not significantly different from that of cholesterol. Lipoproteins were fractioned by ultracentrifugation into VLDL, LDL and HDL. Radioactivities of each fraction in lipoproteins separated by thin layer chromatography showed that fractions containing cholestane-3β, 5α, 6β-triol, 7α- and 7β-hydroxycholesterol and 7-ketocholesterol were more selectively transported in VLDL, whereas most of the 25-hydroxycholesterol was present in LDL. HDL contained only minute amounts of cholesterol oxidation products. 22 refs

  17. Effect of honey on serum cholesterol and lipid values.

    Science.gov (United States)

    Münstedt, Karsten; Hoffmann, Sven; Hauenschild, Annette; Bülte, Michael; von Georgi, Richard; Hackethal, Andreas

    2009-06-01

    Small studies have suggested that honey benefits patients with high cholesterol concentrations. The present study aimed to confirm this finding in a larger group of subjects. Sixty volunteers with high cholesterol, stratified according to gender and hydroxymethylglutaryl-coenzyme A reductase inhibitor (statin) treatment (yes/no), were randomized to receive 75 g of honey solution or a honey-comparable sugar solution once daily over a period of 14 days. Baseline measurements, including body mass index (BMI) and lipid profile, were obtained, and subjects also completed dietary questionnaires and the Inventory for the Assessment of Negative Bodily Affect-Trait form (INKA-h) questionnaire. Measurements were repeated 2 weeks later. BMI and high-density lipoprotein (HDL) cholesterol values were significantly correlated (r = -0.487; P INKA-h scores and LDL cholesterol values were also significantly correlated (r = 0.273, P = .042). Neither solution influenced significantly cholesterol or triglyceride values in the total group; in women, however, the LDL cholesterol value increased in the sugar solution subgroup but not in the women taking honey. Although ingesting honey did not reduce LDL cholesterol values in general, women may benefit from substituting honey for sugar in their diet. Reducing the BMI lowers the LDL cholesterol value, and psychological interventions also seem important and merit further investigation. PMID:19627212

  18. Composition of and cholesterol in Araucana and commercial eggs.

    Science.gov (United States)

    Peterson, D W; Lilyblade, A; Clifford, C K; Ernst, R; Clifford, A J; Dunn, P

    1978-01-01

    Araucana eggs from six sources and commercial-type white eggs of two major supermarket brands and from the University of California flock were collected and analyzed for cholesterol content of the yolk. The yolks of Araucana eggs were significantly higher in cholesterol than those of commercial white eggs. PMID:563887

  19. Cholesterol Balance in Prion Diseases and Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Samia Hannaoui

    2014-11-01

    Full Text Available Prion diseases are transmissible and fatal neurodegenerative disorders of humans and animals. They are characterized by the accumulation of PrPSc, an aberrantly folded isoform of the cellular prion protein PrPC, in the brains of affected individuals. PrPC is a cell surface glycoprotein attached to the outer leaflet of the plasma membrane by a glycosyl-phosphatidyl-inositol (GPI anchor. Specifically, it is associated with lipid rafts, membrane microdomains enriched in cholesterol and sphinoglipids. It has been established that inhibition of endogenous cholesterol synthesis disturbs lipid raft association of PrPC and prevents PrPSc accumulation in neuronal cells. Additionally, prion conversion is reduced upon interference with cellular cholesterol uptake, endosomal export, or complexation at the plasma membrane. Altogether, these results demonstrate on the one hand the importance of cholesterol for prion propagation. On the other hand, growing evidence suggests that prion infection modulates neuronal cholesterol metabolism. Similar results were reported in Alzheimer’s disease (AD: whereas amyloid β peptide formation is influenced by cellular cholesterol, levels of cholesterol in the brains of affected individuals increase during the clinical course of the disease. In this review, we summarize commonalities of alterations in cholesterol homeostasis and discuss consequences for neuronal function and therapy of prion diseases and AD.

  20. Cholesterol and Sphingomyelin-Containing Model Condensed Lipid Monolayers: Heterogeneities Involving Ordered Microdomains Assessed by Two Cholesterol Derivatives.

    Science.gov (United States)

    Lecompte, Marie-France; Gaibelet, Gérald; Lebrun, Chantal; Tercé, François; Collet, Xavier; Orlowski, Stéphane

    2015-11-01

    Lipid monolayers are often considered as model membranes, but they are also the physiologic lipid part of the peripheral envelope of lipoproteins and cytosolic lipid bodies. However, their structural organization is still rather elusive, in particular when both cholesterol and sphingomyelin are present. To investigate such structural organization of hemimembranes, we measured, using alternative current voltammetry, the differential capacitance of condensed phosphatidylcholine-based monolayers as a function of applied potential, which is sensitive to their lipid composition and molecular arrangement. Especially, monolayers containing both sphingomyelin and cholesterol, at 15% w/w, presented specific characteristics of the differential capacitance versus potential curves recorded, which was indicative of specific interactions between these two lipid components. We then compared the behavior of two cholesterol derivatives (at 15% w/w), 21-methylpyrenyl-cholesterol (Pyr-met-Chol) and 22-nitrobenzoxadiazole-cholesterol (NBD-Chol), with that of cholesterol when present in model monolayers. Indeed, these two probes were chosen because of previous findings reporting opposite behaviors within bilayer membranes regarding their interaction with ordered lipids, with only Pyr-met-Chol mimicking cholesterol well. Remarkably, in monolayers containing sphingomyelin or not, Pyr-met-Chol and NBD-Chol presented contrasting behaviors, and Pyr-met-Chol mimicked cholesterol only in the presence of sphingomyelin. These two observations (i.e., optimal amounts of sphingomyelin and cholesterol, and the ability to discriminate between Pyr-met-Chol and NBD-Chol) can be interpreted by the existence of heterogeneities including ordered patches in sphingomyelin- and cholesterol-containing monolayers. Since such monolayer lipid arrangement shares some properties with the raft-type lipid microdomains well-described in sphingomyelin- and cholesterol-containing bilayer membranes, our data thus

  1. Cholesterol interactions with ceramide and sphingomyelin.

    Science.gov (United States)

    García-Arribas, Aritz B; Alonso, Alicia; Goñi, Felix M

    2016-09-01

    Sphingolipids contain in their polar heads chemical groups allowing them to establish a complex network of H-bonds (through different OH and NHgroups) with other lipids in the bilayer. In the recent years the specific interaction of sphingomyelin (SM) with cholesterol (Chol) has been examined, largely in the context of the "lipid raft" hypothesis. Formation of SM-Ceramide (Cer) complexes, proposed to exist in cell membranes in response to stress, has also been described. More recently, a delicate balance of phase formation and transformation in ternary mixtures of SM, Chol and Cer, with mutual displacement of Chol and Cer from their interaction with SM is considered to exist. In addition, data demonstrating direct Chol-Cer interaction are becoming available. PMID:27132117

  2. Ursodeoxycholic Acid for the Treatment of Cholesterol Gallstones

    International Nuclear Information System (INIS)

    Cholesterol is the principal constituent of more than three quarters of gallstones. Pure cholesterol crystals are quite soft, and protein contributes importantly to the strength of cholesterol stones. The risk of gallstones does not correlate with total serum cholesterol levels, but it does correlate with decreased high-density lipoprotein cholesterol and increased triglyceride levels. At least 10 percent of adults have gallstones where female: male ratio of about 2:1 in the younger age groups with increasing prevalence with age. Nine patients with gallstones (6 females and 3 males) were included in the study. Patients were treated with ursodeoxycholic acids tablets in two oral doses, one after breakfast, and the other after dinner for 9 months. Ultrasound examination was repeated every 3 months. Re-examination by abdominal ultrasonography revealed that gallstone 1 cm or less in diameter disappeared within 6 months, and the largest stone 3.06 cm in diameter disappeared within 9 months.

  3. Reverse cholesterol transport: From classical view to new insights

    Directory of Open Access Journals (Sweden)

    Astrid E van der Velde

    2010-12-01

    Full Text Available Cholesterol is of vital importance for the human body. It is a constituent for most biological membranes, it is needed for the formation of bile salts, and it is the precursor for steroid hormones and vitamin D. However, the presence of excess cholesterol in cells, and in particular in macrophages in the arterial vessel wall, might be harmful. The accumulation of cholesterol in arteries can lead to atherosclerosis, and in turn, to other cardiovascular diseases. The route that is primarily thought to be responsible for the disposal of cholesterol is called reverse cholesterol transport (RCT. Therefore, RCT is seen as an interesting target for the development of drugs aimed at the prevention of atherosclerosis. Research on RCT has taken off in recent years. In this review, the classical concepts about RCT are discussed, together with new insights about this topic.

  4. SND1 overexpression deregulates cholesterol homeostasis in hepatocellular carcinoma.

    Science.gov (United States)

    Navarro-Imaz, Hiart; Rueda, Yuri; Fresnedo, Olatz

    2016-09-01

    SND1 is a multifunctional protein participating, among others, in gene transcription and mRNA metabolism. SND1 is overexpressed in cancer cells and promotes viability and tumourigenicity of hepatocellular carcinoma cells. This study shows that cholesterol synthesis is increased in SND1-overexpressing hepatoma cells. Neither newly synthesised nor extracellularly supplied cholesterol are able to suppress this increase; however, inhibition of cholesterol esterification reverted the activated state of sterol-regulatory element-binding protein 2 (SREBP2) and cholesterogenesis. These results highlight SND1 as a potential regulator of cellular cholesterol distribution and homeostasis in hepatoma cells, and support the rationale for the therapeutic use of molecules that influence cholesterol management when SND1 is overexpressed. PMID:27238764

  5. Enzymatic-fluorometric quantification of cholesterol in bovine milk

    DEFF Research Database (Denmark)

    Larsen, Torben

    2012-01-01

    The present paper describes an enzymatic–fluorometric method for the determination of cholesterol in milk and other opaque matrices. The initial step of the method is to liberate chemically and physically bound cholesterol from the milk fat globule membrane by enzymatic action. The method is able...... to discriminate between esterified and free cholesterol in milk. The analysis is cost effective and is developed to work directly on whole, fresh milk thereby eliminating time consuming and tedious pre-treatment procedures of the sample. More than 1000 milk samples were analysed on the day of...... sampling. The total concentration of milk cholesterol ranged from 80 to 756 μM (n = 1068; mean 351 μM). Milk cholesterol was significantly correlated to milk fat concentration as analysed by mid-infra red spectrometry (r = 0.630; n = 853) and by an enzymatic–fluorometric method (triacylglycerol) (r = 0...

  6. Cholesterol-induced protein sorting: an analysis of energetic feasibility

    DEFF Research Database (Denmark)

    Lundbaek, J A; Andersen, O S; Werge, T;

    2003-01-01

    transmembrane domain (TMD). M. S. Bretscher and S. Munro (SCIENCE: 261:1280-1281, 1993) therefore proposed a physical sorting mechanism based on the hydrophobic match between the proteins' TMD and the bilayer thickness, in which cholesterol would regulate protein sorting by increasing the lipid bilayer...... thickness. In this model, Golgi proteins with short TMDs would be excluded from cholesterol-enriched domains (lipid rafts) that are incorporated into transport vesicles destined for the plasma membrane. Although attractive, this model remains unproven. We therefore evaluated the energetic feasibility...... thickness per se, however, have only a modest effect on sorting; the major effect arises because cholesterol changes also the bilayer material properties, which augments the energetic penalty for incorporating short TMDs into cholesterol-enriched domains. We conclude that cholesterol-induced changes...

  7. Cholesterol-binding viral proteins in virus entry and morphogenesis.

    Science.gov (United States)

    Schroeder, Cornelia

    2010-01-01

    Up to now less than a handful of viral cholesterol-binding proteins have been characterized, in HIV, influenza virus and Semliki Forest virus. These are proteins with roles in virus entry or morphogenesis. In the case of the HIV fusion protein gp41 cholesterol binding is attributed to a cholesterol recognition consensus (CRAC) motif in a flexible domain of the ectodomain preceding the trans-membrane segment. This specific CRAC sequence mediates gp41 binding to a cholesterol affinity column. Mutations in this motif arrest virus fusion at the hemifusion stage and modify the ability of the isolated CRAC peptide to induce segregation of cholesterol in artificial membranes.Influenza A virus M2 protein co-purifies with cholesterol. Its proton translocation activity, responsible for virus uncoating, is not cholesterol-dependent, and the transmembrane channel appears too short for integral raft insertion. Cholesterol binding may be mediated by CRAC motifs in the flexible post-TM domain, which harbours three determinants of binding to membrane rafts. Mutation of the CRAC motif of the WSN strain attenuates virulence for mice. Its affinity to the raft-non-raft interface is predicted to target M2 protein to the periphery of lipid raft microdomains, the sites of virus assembly. Its influence on the morphology of budding virus implicates M2 as factor in virus fission at the raft boundary. Moreover, M2 is an essential factor in sorting the segmented genome into virus particles, indicating that M2 also has a role in priming the outgrowth of virus buds.SFV E1 protein is the first viral type-II fusion protein demonstrated to directly bind cholesterol when the fusion peptide loop locks into the target membrane. Cholesterol binding is modulated by another, proximal loop, which is also important during virus budding and as a host range determinant, as shown by mutational studies. PMID:20213541

  8. Correction of enhanced endothelial permeability by cessation of cholesterol feeding

    International Nuclear Information System (INIS)

    Changes in endothelial permeability and the transport of macromolecules may be important in the initiation and/or progression of atherosclerosis. We have previously shown, with a carotid artery preparation isolated in situ with intact adventitia, that long-term cholesterol feeding in rabbits will result in a seven- to tenfold increase in 125I albumin transport across the artery into the systemic circulation. The current studies were undertaken to determine whether this abnormality of enhanced permeability could be reversed by cessation of cholesterol feeding and correction of the hyperlipidemia. Two groups of rabbits were fed either a standard Rabbit Chow or a diet containing 1.5% cholesterol and 5.2% corn oil for 12 to 15 weeks. Another group of rabbits was given cholesterol for 12 to 15 weeks with change to standard rabbit chow for an additional 22 to 24 weeks after which albumin transport studies were then performed. Mean plasma cholesterol level after 12 to 15 weeks of cholesterol feeding was 2052 +/- 395 mg/dl. After the animals were withdrawn from the cholesterol diet for 22 to 24 weeks, the mean plasma cholesterol level decreased to 80 +/- 21 mg/dl. The mean plasma cholesterol value in chow-fed animals was 39 +/- 6 mg/dl. Perfusion studies were done with 125I-labeled albumin and plasma radioactivity served as a measure of transport across the carotid artery. The average level of albumin transport across the artery into venous blood in the cholesterol-fed animals (13,911 dpm/ml of plasma) was significantly greater than that of control animals (2049 dpm/ml of plasma)

  9. Resveratrol Protects Rabbits Against Cholesterol Diet-Induced Hyperlipidaemia.

    Science.gov (United States)

    Tanko, Y; Jimoh, A; Ahmed, A; Mohammed, A; Ayo, J O

    2016-01-01

    The excessive consumption of high cholesterol diet has been associated with an increased incidence oflipidaemia. Lipidaemia is enhanced by formation of oxidative stress, lipid peroxidation and hyperglycaemia. The aim ofthese experiments was to investigate the protective effect of resveratrol co-administered with cholesterol diet inducedhyperlipidaemia in rabbits. Thirty rabbits divided into six groups of five animal (group= 5) each: group 1 = normal control,group 2 = cholesterol diet/high fat diet group only (HFD), group 3 = resveratrol 200 mg/kg (R200), group 4 = resveratrol400 mg/kg (R400), group 5 = HFD + R200 and group 6 = HFD + R400. The normal group was fed with standard animalfeeds only; while the HFD groups were fed with standard animal feeds + cholesterol diet (10% Groundnut oil, 20%Groundnut mill and 2% cholesterol). Resveratrol-treated rabbits received resveratrol suspended in 10 g/Lcarboxymethylcellulose (CMC) and the control group received the vehicle only, CMC. The preparations were administeredfor 8 weeks of experimental protocol. At the end of the study period, the animals were sacrificed. Blood and plasma sampleswere collected. Serum evaluation of lipid profile such as total cholesterol (TC), triacylglycerol (Tg), low density lipoproteincholesterol (LDP-c) and high density lipoprotein cholesterol (HDL-c) were also assessed. The results obtained showsignificant (P < 0.05) decrease in total cholesterol (TC), Low density lipoprotein cholesterol (LDP-c), total triacylglyceroland an increase in high density lipoprotein cholesterol (HDL-c) in resveratrol treated groups compared to HFD group only.In conclusion, the findings indicated that Resveratrol may contain polar products able to lower plasma lipid concentrationsand might be beneficial in treatment of hyperlipidemia and atherosclerosis. PMID:27574767

  10. Bacterial colonization of host cells in the absence of cholesterol.

    Directory of Open Access Journals (Sweden)

    Stacey D Gilk

    2013-01-01

    Full Text Available Reports implicating important roles for cholesterol and cholesterol-rich lipid rafts in host-pathogen interactions have largely employed sterol sequestering agents and biosynthesis inhibitors. Because the pleiotropic effects of these compounds can complicate experimental interpretation, we developed a new model system to investigate cholesterol requirements in pathogen infection utilizing DHCR24(-/- mouse embryonic fibroblasts (MEFs. DHCR24(-/- MEFs lack the Δ24 sterol reductase required for the final enzymatic step in cholesterol biosynthesis, and consequently accumulate desmosterol into cellular membranes. Defective lipid raft function by DHCR24(-/- MEFs adapted to growth in cholesterol-free medium was confirmed by showing deficient uptake of cholera-toxin B and impaired signaling by epidermal growth factor. Infection in the absence of cholesterol was then investigated for three intracellular bacterial pathogens: Coxiella burnetii, Salmonella enterica serovar Typhimurium, and Chlamydia trachomatis. Invasion by S. Typhimurium and C. trachomatis was unaltered in DHCR24(-/- MEFs. In contrast, C. burnetii entry was significantly decreased in -cholesterol MEFs, and also in +cholesterol MEFs when lipid raft-associated α(Vβ(3 integrin was blocked, suggesting a role for lipid rafts in C. burnetii uptake. Once internalized, all three pathogens established their respective vacuolar niches and replicated normally. However, the C. burnetii-occupied vacuole within DHCR24(-/- MEFs lacked the CD63-positive material and multilamellar membranes typical of vacuoles formed in wild type cells, indicating cholesterol functions in trafficking of multivesicular bodies to the pathogen vacuole. These data demonstrate that cholesterol is not essential for invasion and intracellular replication by S. Typhimurium and C. trachomatis, but plays a role in C. burnetii-host cell interactions.

  11. Cholesterol Levels: What You Need to Know | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: High Cholesterol Cholesterol Levels: What You Need to Know Past Issues / Summer 2012 Table of Contents Measuring Cholesterol Levels Learn more at MedlinePlus: https://medlineplus.gov/ ...

  12. High Blood Cholesterol Q&A Dr. Michael Lauer | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: High Cholesterol High Blood Cholesterol Q&A with Dr. Michael Lauer Past Issues / ... heavier and older, what does recent research on cholesterol and heart health tell us that Americans need ...

  13. Dose effects of dietary phytosterols on cholesterol metabolism: a controlled feeding study123

    OpenAIRE

    Racette, Susan B.; Lin, Xiaobo; Lefevre, Michael; Spearie, Catherine Anderson; MOST, MARLENE M.; Ma, Lina; Ostlund, Richard E

    2009-01-01

    Background: Phytosterol supplementation of 2 g/d is recommended by the National Cholesterol Education Program to reduce LDL cholesterol. However, the effects of different intakes of phytosterol on cholesterol metabolism are uncertain.

  14. The influence of cholesterol and biomass concentration on the uptake of cholesterol by Lactobacillus from MRS broth

    Directory of Open Access Journals (Sweden)

    Małgorzata Ziarno

    2007-06-01

    Full Text Available The aim of this study was the determination of some factors influence (i.e. the vitality of bacteria cells and the cholesterol concentration on the ability of selected Lactobacillus sp. to cholesterol uptake during culture in MRS broth. Three Lactobacillus strains (Lb. delbrueckii subsp. bulgaricus, Lb. acidophilus, Lb. casei isolated from commercial single species lyophilized dairy starter cultures and three Lactobacillus strains (Lb. plantarum, Lb. delbrueckii subsp. bulgaricus, Lb. acidophilus originated from commercial pharmaceuticals were used in this study. The uptake of cholesterol from MRS broth during the growth of Lactobacillus sp., expressed as the difference between the final and the initial concentrations of cholesterol, ranged from 0.053 to 0.153 g/dm³, apart from the initial cholesterol content and the origin of Lactobacillus sp. The results confirmed that biomass concentration have a statistically significant effect on uptake of cholesterol. The ten-fold increase of the amount of intact cells biomass caused about 1.5-2-fold increase of the amount of cholesterol removed. The influence of the concentration of biomass of alive cells on the removal of cholesterol was bigger than in case of the heat-sterilized cells.

  15. How cholesterol interacts with membrane proteins: an exploration of cholesterol-binding sites including CRAC, CARC and tilted domains

    Directory of Open Access Journals (Sweden)

    FranciscoJBarrantes

    2013-02-01

    Full Text Available The plasma membrane of eukaryotic cells contains several types of lipids displaying high biochemical variability in both their apolar moiety (e.g. the acyl chain of glycerolipids and their polar head (e.g. the sugar structure of glycosphingolipids. Among these lipids, cholesterol is unique because its biochemical variability is almost exclusively restricted to the oxidation of its polar -OH group. Although generally considered the most rigid membrane lipid, cholesterol can adopt a broad range of conformations due to the flexibility of its isooctyl chain linked to the polycyclic sterane backbone. Moreover, cholesterol is an asymmetric molecule displaying a planar face and a rough  face. Overall, these structural features open up a number of possible interactions between cholesterol and membrane lipids and proteins, consistent with the prominent regulatory functions that this unique lipid exerts on membrane components. The aim of this review is to describe how cholesterol interacts with membrane lipids and proteins at the molecular/atomic scale, with special emphasis on transmembrane domains of proteins containing either the consensus cholesterol-binding motifs CRAC and CARC or a tilted peptide. Despite their broad structural diversity, all these domains bind cholesterol through common molecular mechanisms, leading to the identification of a subset of amino acid residues that are overrepresented in both linear and three-dimensional membrane cholesterol-binding sites.

  16. Asymptotic Likelihood Distribution for Correlated & Constrained Systems

    CERN Document Server

    Agarwal, Ujjwal

    2016-01-01

    It describes my work as summer student at CERN. The report discusses the asymptotic distribution of the likelihood ratio for total no. of parameters being h and 2 out of these being are constrained and correlated.

  17. Incorporation of 4-14C labeled cholesterol into the cholesterol ester fractions of plasma lipoproteins in patients with cirrhosis of the liver

    International Nuclear Information System (INIS)

    In vivo incorporation studies with 4-14C-cholesterol were performed in five patients cirrhosis of the liver. All patients showed low concentrations of total cholesterol, esterified cholesterol, and a low activity of the lecithin:cholesterol acyltransferase activity (LCAT). The pattern of incorporation corresponded to the results known from hypercholesterolemic, normocholesterolemic and hypertriglyceridemic patients. Low cholesterol ester concentrations and low LCAT activity do not modify the pattern of incorporation into the lipoprotein ester fractions. (orig.)

  18. Cholesterol organization in membranes at low concentrations: effects of curvature stress and membrane thickness.

    OpenAIRE

    Rukmini, R; Rawat, S S; Biswas, S. C.; Chattopadhyay, A

    2001-01-01

    Cholesterol is often found distributed nonrandomly in domains in biological and model membranes and has been reported to be distributed heterogeneously among various intracellular membranes. Although a large body of literature exists on the organization of cholesterol in plasma membranes or membranes with high cholesterol content, very little is known about organization of cholesterol in membranes containing low amounts of cholesterol. Using a fluorescent cholesterol analog (25-[N-[(7-nitrobe...

  19. Serum albumin acts as a shuttle to enhance cholesterol efflux from cells[S

    OpenAIRE

    Sankaranarayanan, Sandhya; de la Llera-Moya, Margarita; Drazul-Schrader, Denise; Phillips, Michael C.; Kellner-Weibel, Ginny; Rothblat, George H.

    2013-01-01

    An important mechanism contributing to cell cholesterol efflux is aqueous transfer in which cholesterol diffuses from cells into the aqueous phase and becomes incorporated into an acceptor particle. Some compounds can enhance diffusion by acting as shuttles transferring cholesterol to cholesterol acceptors, which act as cholesterol sinks. We have examined whether particles in serum can enhance cholesterol efflux by acting as shuttles. This task was accomplished by incubating radiolabeled J774...

  20. Binding of fluorescently labeled cholera toxin subunit B to glycolipids in the human submandibular gland and inhibition of binding by periodate oxidation and by galactose.

    Science.gov (United States)

    Kirkeby, S

    2016-01-01

    FITC-labeled cholera toxin subunit B (CTB) stained the surfaces of cells of mucous acini in the submandibular gland. CTB, also called choleragenoid, binds to the GM1 glycolipid in the cell membrane. The binding in most acini was inhibited by periodic acid oxidation of the sections, while some acini remained unaffected even after increased oxidation. Staining with the subunit was also reduced significantly by adding galactose to the incubation medium. Binding of CTB to cell surfaces apparently requires intact sialic groups on most, but not all, cell surfaces. Oxidation of the sialic acid residues may influence the structure of the sialylated GM1 molecules on the cell surface in different ways. It is possible that both the sialic acid residue and the terminal galactose are oxidized. Alternatively, the sialic acid may be resistant to acid hydrolysis in gangliosides in which the sialic acid is attached to the internal galactose residue linked to GalNAc, as in the GM1 glycolipid. Inhibition of the GM1 receptor binding to cholera toxin has potential for protection of humans against cholera. Galactose and agents that modify sialic acid inhibit the accessibility of the toxin to the GM1 carbohydrate receptor. Human milk contains high levels of sialic acid glycoconjugates that may provide defense mechanisms. PMID:26472148

  1. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Akihisa, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de; Tanaka, Motomu, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501 (Japan); Abuillan, Wasim; Körner, Alexander [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Burk, Alexandra S. [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Ries, Annika [Institute of Organic and Biomolecular Chemistry, University of Göttingen, 37077 Göttingen (Germany); Werz, Daniel B. [Institute of Organic Chemistry, Technische Universität Braunschweig, 38106 Braunschweig (Germany); Demé, Bruno [Institut Laue-Langevin, 38042 Grenoble Cedex 9, Grenoble (France)

    2015-04-21

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier “bent” Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter “bent” disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  2. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    International Nuclear Information System (INIS)

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier “bent” Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter “bent” disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3

  3. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    Science.gov (United States)

    Yamamoto, Akihisa; Abuillan, Wasim; Burk, Alexandra S.; Körner, Alexander; Ries, Annika; Werz, Daniel B.; Demé, Bruno; Tanaka, Motomu

    2015-04-01

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier "bent" Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter "bent" disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  4. Constrained Bimatrix Games in Wireless Communications

    OpenAIRE

    Firouzbakht, Koorosh; Noubir, Guevara; Salehi, Masoud

    2015-01-01

    We develop a constrained bimatrix game framework that can be used to model many practical problems in many disciplines, including jamming in packetized wireless networks. In contrast to the widely used zero-sum framework, in bimatrix games it is no longer required that the sum of the players' utilities to be zero or constant, thus, can be used to model a much larger class of jamming problems. Additionally, in contrast to the standard bimatrix games, in constrained bimatrix games the players' ...

  5. Constrained school choice : an experimental study

    OpenAIRE

    Calsamiglia, Caterina; Haeringer, Guillaume; Klijn, Flip

    2008-01-01

    The literature on school choice assumes that families can submit a preference list over all the schools they want to be assigned to. However, in many real-life instances families are only allowed to submit a list containing a limited number of schools. Subjects' incentives are drastically affected, as more individuals manipulate their preferences. Including a safety school in the constrained list explains most manipulations. Competitiveness across schools plays an important role. Constraining...

  6. Dietary Cholesterol Affects Plasma Lipid Levels, the Intravascular Processing of Lipoproteins and Reverse Cholesterol Transport without Increasing the Risk for Heart Disease

    Directory of Open Access Journals (Sweden)

    Jacqueline Barona

    2012-08-01

    Full Text Available The associations between dietary cholesterol and heart disease are highly controversial. While epidemiological studies and clinical interventions have shown the lack of correlation between cholesterol intake and cardiovascular disease (CVD risk, there is still concern among health practitioners and the general population regarding dietary cholesterol. In this review, several clinical studies utilizing cholesterol challenges are analyzed in terms of changes that occur in lipoprotein metabolism resulting from excess consumption of cholesterol. Dietary cholesterol has been shown to increase both LDL and HDL in those individuals who respond to a cholesterol challenge without altering the LDL cholesterol/HDL cholesterol ratio, a key marker of CVD risk. Further, dietary cholesterol has been shown to increase only HDL with no changes in LDL with average cholesterol consumption and during weight loss interventions. Ingestion of cholesterol has also been shown to increase the size of both LDL and HDL particles with the associated implications of a less atherogenic LDL particle as well as more functional HDL in reverse cholesterol transport. Other changes observed in lipoprotein metabolism are a greater number of large LDL and decreases in small LDL subfractions. All this information put together points to specific roles of dietary cholesterol in substantially altering intravascular processing of lipoproteins as well as reverse cholesterol transport.

  7. CHOLESTEROL LEVELS AND SUICIDAL BEHAVIOR: A CASE CONTROL STUDY

    Directory of Open Access Journals (Sweden)

    Nikhil

    2014-06-01

    Full Text Available BACKGROUND: In modern psychiatry, there is a movement to understand mental health, not solely based on behaviors and subjective report, but also based on objective markers of illness. Several studies have focused on a relationship between serum cholesterol levels and aggressive behaviors including suicide. AIM: To identify a potential link between cholesterol and suicidal behavior. MATERIAL AND METHODS: 150 patients with psychiatry diagnosis were divided into three equal groups (50 each: those who had a recent suicidal attempt, those who had suicidal ideations but no attempts and those with psychiatry diagnosis but no suicidal ideations and attempts. Blood sample for total cholesterol level was on IPD or OPD basis. The study was started after taking approval from institute ethical committee. Analysis was done using Chi square test. OBSERVATIONS AND RESULTS: It was found that maximum patients who attempted suicide belonged to major depression and schizophrenia followed by substance dependence and bipolar affective disorder (BPAD with major depression and there was statistical difference in cholesterol levels of patients with suicide attempt, with suicidal ideations and control group. 42% and 44% of major depression and schizophrenia cases respectively had low total serum cholesterol levels (below 160 mg%. CONCLUSION: There is a potential link between serum total cholesterol levels and suicidal behavior. Taking the literature as a whole there is substantial evidence that low cholesterol levels are found in suicidal behaviors of various psychiatric illnesses especially major depressive disorder, schizophrenia, substance dependence and bipolar depressive disorder

  8. Quantitation of cholesterol oxidation products in unirradiated and irradiated meats

    International Nuclear Information System (INIS)

    A method to detect 7-ketocholesterol, cholesterol-5β,6β-epoxide, cholesterol-5α,6α-epoxide, 4-cholesten-3-one, 4,6-cholestadien-3-one and 4-cholestene-3,6-dione in unirradiated and irradiated beef, pork and veal was developed by use of chloroform-methanol-water extraction, solid-phase extraction, column separation, thin-layer chromatography and gas chromatography. This method recovered 78–88% of the cholesterol oxidation products and detected the cholesterol oxidation products at 10 ppb or higher. Irradiation of the meats to a dose of 10 kGy increased these compounds, except 4,6-cholestadien-3-one for all three types of meat, over unirradiated, and except cholesterol-5α,6α-epoxide and 4-cholesten-3-one for the pork. All the cholesterol oxidation products in the unirradiated meats increased during storage at 0–4°C for 2 wk with some exceptions for the pork. The increases of cholesterol oxidation products in stored irradiated meats were greater than those in the unirradiated

  9. Cholesterol induces fetal rat enterocyte death in culture

    Directory of Open Access Journals (Sweden)

    Gazzola J.

    2004-01-01

    Full Text Available The effect of cholesterol on fetal rat enterocytes and IEC-6 cells (line originated from normal rat small intestine was examined. Both cells were cultured in the presence of 20 to 80 µM cholesterol for up to 72 h. Apoptosis was determined by flow cytometric analysis and fluorescence microscopy. The expression of HMG-CoA reductase and peroxisome proliferator-activated receptor gamma (PPARgamma was measured by RT-PCR. The addition of 20 µM cholesterol reduced enterocyte proliferation as early as 6 h of culture. Reduction of enterocyte proliferation by 28 and 41% was observed after 24 h of culture in the presence and absence of 10% fetal calf serum, respectively, with the effect lasting up to 72 h. Treatment of IEC-6 cells with cholesterol for 24 h raised the proportion of cells with fragmented DNA by 9.7% at 40 µM and by 20.8% at 80 µM. When the culture period was extended to 48 h, the effect of cholesterol was still more pronounced, with the percent of cells with fragmented DNA reaching 53.5% for 40 µM and 84.3% for 80 µM. Chromatin condensation of IEC-6 cells was observed after treatment with cholesterol even at 20 µM. Cholesterol did not affect HMG-CoA reductase expression. A dose-dependent increase in PPARgamma expression in fetal rat enterocytes was observed. The expression of PPAR-gamma was raised by 7- and 40-fold, in the presence and absence of fetal calf serum, respectively, with cholesterol at 80 mM. The apoptotic effect of cholesterol on enterocytes was possibly due to an increase in PPARgamma expression.

  10. Cholesterol and fat lowering with hydrophobic polysaccharide derivatives.

    Science.gov (United States)

    Čopíková, Jana; Taubner, Tomáš; Tůma, Jan; Synytsya, Andriy; Dušková, Dagmar; Marounek, Milan

    2015-02-13

    Hydrophobic derivatives of highly methylated citrus pectin, chitosan and cellulose were prepared and tested as potential cholesterol lowering agents. Elemental analysis and spectroscopic methods confirmed high substitution degree for all of them. Substitution with long alkyl/acyl groups led to significant changes in physical and thermal properties of modified polysaccharides. Sorption of cholate and cholesterol by these polysaccharide-based sorbents was estimated in comparison with the synthetic drug cholestyramine. It was found that modified polysaccharides have high affinity to cholesterol. By contrast, cholestyramine was effective only in cholate sorption. PMID:25458291

  11. Lipid-based transfection reagents can interfere with cholesterol biosynthesis.

    Science.gov (United States)

    Danielli, Mauro; Marinelli, Raúl A

    2016-02-15

    Lipid-based transfection reagents are widely used for delivery of small interfering RNA into cells. We examined whether the commonly used commercial transfection reagents DharmaFECT-4 and Lipofectamine 2000 can interfere with lipid metabolism by studying cholesterogenesis. Cholesterol de novo synthesis from [(14)C]acetate was assessed in human hepatocyte-derived Huh-7 cells. The results revealed that DharmaFECT, but not Lipofectamine, markedly inhibited cholesterol biosynthesis by approximately 70%. Cell viability was not significantly altered. These findings suggest that caution is required in the choice of certain lipid-based transfection reagents for gene silencing experiments, particularly when assessing cholesterol metabolism. PMID:26656923

  12. Reverse cholesterol transport: From classical view to new insights

    Institute of Scientific and Technical Information of China (English)

    Astrid; E; van; der; Velde

    2010-01-01

    Cholesterol is of vital importance for the human body. It is a constituent for most biological membranes, it is needed for the formation of bile salts, and it is the pre- cursor for steroid hormones and vitamin D. However, the presence of excess cholesterol in cells, and in particular in macrophages in the arterial vessel wall, might be harmful. The accumulation of cholesterol in arteries can lead to atherosclerosis, and in turn, to other cardiovascular diseases. The route that is primarily thought to be re...

  13. Does fat in milk, butter and and cholesterol differently?

    DEFF Research Database (Denmark)

    Tholstrup, T,; Høy, Carl-Erik; Andersen, L.N.;

    2004-01-01

    8 hours following intake of the meals. Results: Fasting LDL cholesterol concentration was significantly higher after butter than cheese diet (p 0.037), with a borderline significant difference in total cholesterol (p = 0.054) after the experimental periods of three weeks. Postprandial glucose showed...... a higher response after cheese diet than after milk diet (p = 0.010, diet X time interaction). Conclusions: A different effect of fat in milk and butter could not be confirmed in this study. The moderately lower LDL cholesterol after cheese diet compared to butter diet should be investigated further....

  14. Statins: Cholesterol guidelines and Indian perspective

    Directory of Open Access Journals (Sweden)

    Anil S Menon

    2015-01-01

    Full Text Available Statins have become an important drug in preventing the occurrence of atherosclerotic cardiovascular disease (ASCVD. The effectiveness of statins in reducing ASCVD has been established in large-scale clinical trials. The lipid management guidelines have been periodically modified due to accumulating evidence about the proportionate benefit achieved with a progressive reduction in cholesterol levels with higher doses of statins and even in those at low risk of development of ASCVD. The current American College of Cardiology/American Heart Association guidelines have based its recommendations from data gathered exclusively from randomized controlled trials. It has simplified the use of statins, but also raised questions regarding the validity of its cardiovascular event risk prediction tool. Epidemiology of cardiovascular disease in India differs from the western population; there is an increased the prevalence of metabolic syndrome and atherogenic dyslipidemia phenotype a group not addressed in the current guidelines. The guidelines are based on trials, which do not have a representative South Asian population. This article reviews the relevant literature, and examines the issues involved in adopting the guidelines to the Indian population.

  15. Assessing Cholesterol Storage in Live Cells and C. elegans by Stimulated Raman Scattering Imaging of Phenyl-Diyne Cholesterol

    Science.gov (United States)

    Lee, Hyeon Jeong; Zhang, Wandi; Zhang, Delong; Yang, Yang; Liu, Bin; Barker, Eric L.; Buhman, Kimberly K.; Slipchenko, Lyudmila V.; Dai, Mingji; Cheng, Ji-Xin

    2015-01-01

    We report a cholesterol imaging method using rationally synthesized phenyl-diyne cholesterol (PhDY-Chol) and stimulated Raman scattering (SRS) microscope. The phenyl-diyne group is biologically inert and provides a Raman scattering cross section that is 88 times larger than the endogenous C = O stretching mode. SRS microscopy offers an imaging speed that is faster than spontaneous Raman microscopy by three orders of magnitude, and a detection sensitivity of 31 μM PhDY-Chol (~1,800 molecules in the excitation volume). Inside living CHO cells, PhDY-Chol mimics the behavior of cholesterol, including membrane incorporation and esterification. In a cellular model of Niemann-Pick type C disease, PhDY-Chol reflects the lysosomal accumulation of cholesterol, and shows relocation to lipid droplets after HPβCD treatment. In live C. elegans, PhDY-Chol mimics cholesterol uptake by intestinal cells and reflects cholesterol storage. Together, our work demonstrates an enabling platform for study of cholesterol storage and trafficking in living cells and vital organisms.

  16. The origin of cholesterol in chyle demonstrated by nuclear indicator methods; Origines du cholesterol du chyle mises en evidence par la methode des indicateurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, M

    1962-07-01

    In order to obtain information about the mechanism of the intestinal absorption of cholesterol, rats having a lymphatic abdominal fistula are used. The animals receive either 4-{sup 14}C- cholesterol subcutaneously or orally, or the 1-{sup 14}C acetate. The study of the specific radio-activities of the cholesterol in chyle, in serum, in the lining, and in the intestinal contents makes it possible to define the roles played by the transfer cholesterol from the serum, by the cholesterol synthesised intestinally, and by the absorption cholesterol, in the formations of the lymph and of the chylomicrons. A new theory is proposed for the mechanism of cholesterol absorption. (author) [French] Pour obtenir des renseignements concernant le mecanisme de l'absorption intestinale du cholesterol, on utilise des rats porteurs d'une fistule lymphatique abdominale. Les animaux recoivent soit du cholesterol 4-{sup 14}C par voie sous-cutanee ou par voie orale, soit de l'acetate 1-{sup 14}C. L'etude des radioactivites specifiques du cholesterol du chyle, du serum, de la paroi et du contenu intestinal permet de preciser les roles joues par le cholesterol de transfert d'origine serique, par le cholesterol de synthese intestinale et par le cholesterol d'absorption, dans la formation de la lymphe et des chylomicrons. Une theorie nouvelle concernant le mecanisme de l'absorption du cholesterol est proposee. (auteur)

  17. Comparison of biosensors based on entrapment of cholesterol oxidase and cholesterol esterase in electropolymerized films of polypyrrole and diaminonaphthalene derivatives for amperometric determination of cholesterol.

    Science.gov (United States)

    Vidal, J C; Garcia-Ruiz, E; Espuelas, J; Aramendia, T; Castillo, J R

    2003-09-01

    Cholesterol amperometric biosensors constructed with enzymes entrapped in electropolymerized layers of polypyrrole and poly-naphthalene derivative polymers are compared. The biosensors are based on entrapment of cholesterol oxidase and/or cholesterol esterase in monolayer or multilayer films electrochemically synthesised from pyrrole, 1,8-diaminonaphthalene (1,8-DAN), and 1,5-diaminonaphthalene (1,5-DAN) monomers. Seven configurations were assayed and compared, and different analytical properties were obtained depending on the kind of polymer and the arrangement of the layers. The selectivity properties were evaluated for the different monolayer and bilayer configurations proposed as a function of the film permeation factor. All the steps involved in the preparation of the biosensors and determination of cholesterol were carried out in a flow system. Sensitivity and selectivity depend greatly on hydrophobicity, permeability, compactness, thickness, and the kind of the polymer used. In some cases a protective outer layer of non-conducting poly( o-phenylenediamine) polymer improves the analytical characteristics of the biosensor. A comparative study was made of the analytical performance of each of the configurations developed. The biosensors were also applied to the flow-injection determination of cholesterol in a synthetic serum. PMID:12923606

  18. Toxin a from Clostridium difficile binds to rabbit erythrocyte glycolipids with therminal Galα1-3Galβ1-4GlcNaC sequences

    International Nuclear Information System (INIS)

    Toxin A is one of two clostridial toxins implicated as the causative agent of pseudomembranous colitis in patients undergoing postoperative antibiotic therapy. Evidence that the carbohydrate binding determinant for this toxin is a glycoconjugate(s) with non-reducing Galα1-3Galβ1-4GlcNAc has recently been reported. Specific agglutination of rabbit erythrocytes by Toxin A is inhibited by bovine thyroglobulin and prevented by pretreatment of cells with α-galactosidase. Total lipid extracts from rabbit erythrocytes were subjected to thin layer chromatography and the chromatogram overlaid with purified 125I-labeled Toxin A. Two major and several minor toxin-binding glycolipids were detected following autoradiography. The major toxin-binding glycolipids were identified as pentasaccharide- and decasaccharide-ceramides expressing terminal Galα1-3Galβ1-4GlcNAc sequences. Treatment of the toxin-binding glycolipids with α-galactosidase abolished binding. Forsmann glycolipid, globoside, Galα1-4 Galβ1-4Glc-cer, and Galα1-3Galβ1-4Glc-cer did not bind the toxin. These observations are consistent with the proposed carbohydrate specificity of the toxin for the non-reducing terminal sequence, Galα1-3Galβ1-4GlcNAc

  19. Adrenal scanning with {sup 131}I-cholesterol; Diagnostik von Nebennierenrindenerkrankungen mit {sup 131}I-Cholesterol

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, K. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany)

    2009-03-15

    Adrenal scanning with {sup 131}I-19-cholesterol is used in patients with various forms of adrenal malfunction (adreno-cortical carcinoma or adenoma, hypothalamic-hypophyseal form of Cushing's syndrome, adrenal hirsutism, primary or secondary adrenocortical insufficiency). Adrenal scanning is optimal between the fourth and tenth day after intravenous injection of {sup 131}I-19-cholesterol. This method makes it possible to estimate the size and functional status of the adrenals. Limitation of the method is the relatively high radiation dose of {sup 131}I-19-cholesterol. (orig.)

  20. Cholesterol granuloma of the orbit: An atypical presentation

    Directory of Open Access Journals (Sweden)

    Syed A R Rizvi

    2014-01-01

    Full Text Available Cholesterol granuloma is a rare, well-defined lesion of the orbit. In the orbit, diploe of the frontal bone is involved almost exclusively. We report an atypical case of cholesterol granuloma involving superomedial quadrant of orbit. A 42-year-old male presented with progressive, painless, proptosis with infero-temporal displacement of left eye. A large mass was felt beneath the bony orbital margin in the superomedial quadrant of the left orbit. Computerized tomography (CT scan revealed an extraconal superomedial, heterogeneous enhancing mass which was isodense with brain and pushing the globe inferolaterally and anteriorly. Excision biopsy of the tumor revealed the typical features of a cholesterol granuloma without any epithelial elements. Cholesterol granuloma of the orbit is a rare entity, but it can be diagnosed and differentiated from other lesions of the superior orbit by its characteristic clinical, radiological and histopathological features. An appropriate intervention in time carries a good prognosis with almost no recurrence.

  1. Alternative to decrease cholesterol in sheep milk cheeses.

    Science.gov (United States)

    Gómez-Cortés, P; Viturro, E; Juárez, M; de la Fuente, M A

    2015-12-01

    The presence of cholesterol in foods is of nutritional interest because high levels of this molecule in human plasma are associated with an increasing risk of cardiovascular disease and nowadays consumers are demanding healthier products. The goal of this experiment was to diminish the cholesterol content of Manchego, the most popular Spanish cheese manufactured from ewes milk. For this purpose three bulk milks coming from dairy ewe fed with 0 (Control), 3 and 6% of linseed supplement on their diet were used. Nine cheeses (3 per bulk milk) were manufactured and ripened for 3 months. Cholesterol of ewes milk cheese from 6% to 12% linseed supplemented diets decreased by 9.6% and 16.1% respectively, therefore supplying a healthier profile. In a second experiment, different sources of unsaturated fatty acids (rich in oleic, linoleic and α-linolenic acids) were supplemented to dairy ewes and no significant differences were found on cheese cholesterol levels. PMID:26041199

  2. Three cases of cholesterol granuloma in the mandible

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Min Jung; Huh, Kyung Hoe; Yi, Won Jin; Moon, Je Woon; Choi, Soon Chul [Seoul National Univ. School of Dentitry, Seoul (Korea, Republic of); Shin, Jae Myung [Inje Univ. College of Medicine, Kimhae (Korea, Republic of)

    2007-12-15

    Cholesterol granuloma is an unusual clinical entity described as an inflammatory granulation in response to the deposit of cholesterol crystals. It can develop in any portion of air cells within the temporal bone as a result of a lack of aeration and inadequate drainage, especially in the middle ear cavity. Here, we report very unusual three cases of cholesterol granuloma developed in mandible. In the first case a 68-year-old male with a large mass arising from the mandible was observed. Panoramic radiograph and computed tomography scans revealed a huge expanding lesion in the mandible. In the second case a 47-years-old female with a cystic lesion in the mandible was observed. And in the third case a 19-year-old male complaining atypical facial pain had a large lesion in the mandibular ramous. The histopathologic examinations of the cases showed numerous cholesterol crystal surrounded by multinucleated foreign body giant cells.

  3. Helical synthetic peptides that stimulate cellular cholesterol efflux

    Science.gov (United States)

    Bielicki, John K.; Natarajan, Pradeep

    2010-04-06

    The present invention provides peptides comprising at least one amphipathic alpha helix and having an cholesterol mediating activity and a ABCA stabilization activity. The invention further provides methods of using such peptides.

  4. Preterm delivery and low maternal serum cholesterol level: any correlation?

    Directory of Open Access Journals (Sweden)

    Ayodeji A. Oluwole

    2014-04-01

    Results: The study showed an incidence of 5.0% for preterm delivery in the low risk study patients. Preterm birth was 4.83-times more common with low total maternal cholesterol than with midrange total cholesterol (11.8% versus 2.2%, P = 0.024. Conclusions: We can infer from the study that the low maternal serum cholesterol (hypocholesterolaemia is associated with preterm delivery. We can therefore recommend on this basis that the concept of an optimal range for maternal serum cholesterol during pregnancy may have merit and pregnant women should be encouraged to follow a healthy, balanced diet and ensure regular antenatal visit to their healthcare provider. [Int J Reprod Contracept Obstet Gynecol 2014; 3(2.000: 442-446

  5. Interaction between cholesterol and chitosan in Langmuir monolayers

    Directory of Open Access Journals (Sweden)

    Felippe J. Pavinatto

    2005-06-01

    Full Text Available Chitosan incorporated in the aqueous subphase is found to affect the Langmuir monolayers of cholesterol, causing the surface pressure and the surface potential isotherms to become more expanded. The mean molecular area per cholesterol molecule in the condensed monolayer increases from 53 Ų in the absence of chitosan to 61 Ų for a concentration of 0.100 mg/mL of chitosan in the subphase. If additional chitosan is incorporated in the subphase, no change is noted, which points to saturation in the effects from chitosan. The interaction between chitosan and cholesterol probably occurs via hydrogen bonding. The monolayer expansion is also manifested in the monolayer morphology, as indicated by Brewster angle microscopy measurements, where larger cholesterol domains are visualized when chitosan is present in the subphase.

  6. Genetic High-Cholesterol Condition More Common Than Thought

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_157755.html Genetic High-Cholesterol Condition More Common Than Thought Researchers ... the United States, she said. Rates of the genetic disorder vary based on racial/ethnic background, but ...

  7. Cholesterol-Lowering Probiotics as Potential Biotherapeutics for Metabolic Diseases

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2012-01-01

    Full Text Available Cardiovascular diseases are one of the major causes of deaths in adults in the western world. Elevated levels of certain blood lipids have been reported to be the principal cause of cardiovascular disease and other disabilities in developed countries. Several animal and clinical trials have shown a positive association between cholesterol levels and the risks of coronary heart disease. Current dietary strategies for the prevention of cardiovascular disease advocate adherence to low-fat/low-saturated-fat diets. Although there is no doubt that, in experimental conditions, low-fat diets offer an effective means of reducing blood cholesterol concentrations on a population basis, these appear to be less effective, largely due to poor compliance, attributed to low palatability and acceptability of these diets to the consumers. Due to the low consumer compliance, attempts have been made to identify other dietary components that can reduce blood cholesterol levels. Supplementation of diet with fermented dairy products or lactic acid bacteria containing dairy products has shown the potential to reduce serum cholesterol levels. Various approaches have been used to alleviate this issue, including the use of probiotics, especially Bifidobacterium spp. and Lactobacillus spp.. Probiotics, the living microorganisms that confer health benefits on the host when administered in adequate amounts, have received much attention on their proclaimed health benefits which include improvement in lactose intolerance, increase in natural resistance to infectious disease in gastrointestinal tract, suppression of cancer, antidiabetic, reduction in serum cholesterol level, and improved digestion. In addition, there are numerous reports on cholesterol removal ability of probiotics and their hypocholesterolemic effects. Several possible mechanisms for cholesterol removal by probiotics are assimilation of cholesterol by growing cells, binding of cholesterol to cellular surface

  8. Cholesterol Check (A Minute of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-09-10

    Heart disease and stroke are among the leading causes of death in the U.S. One of the main risk factors is high blood cholesterol. In this podcast, Dr. Carla Mercado discusses the importance of a healthy diet and regular screening to prevent high blood cholesterol.  Created: 9/10/2015 by MMWR.   Date Released: 9/10/2015.

  9. Dietary fat, cholesterol and colorectal cancer in a prospective study

    OpenAIRE

    Järvinen, R.; Knekt, P; Hakulinen, T; Rissanen, H; Heliövaara, M

    2001-01-01

    The relationships between consumption of total fat, major dietary fatty acids, cholesterol, consumption of meat and eggs, and the incidence of colorectal cancers were studied in a cohort based on the Finnish Mobile Clinic Health Examination Survey. Baseline (1967–1972) information on habitual food consumption over the preceding year was collected from 9959 men and women free of diagnosed cancer. A total of 109 new colorectal cancer cases were ascertained late 1999. High cholesterol intake was...

  10. Reverse cholesterol transport: a potential therapeutic target for atherosclerosis

    OpenAIRE

    Ying ZHAO

    2011-01-01

    Atherosclerosis is the major cause of death in the Western society due to the development of acute clinical events such as myocardial infarction and cerebral stroke. Currently, lowering plasma LDL cholesterol (LDL-C) levels using statins, inhibitors of de-novo cholesterol synthesis, is the main therapeutic strategy to prevent the progression of atherosclerosis. The remaining high incidence of cardiovascular disease indicates a clear need for new therapies. Numerous epidemiological studies hav...

  11. Tissue cholesterol content alterations in streptozotocin-induced diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Xin-ting WANG; Jia LI; Li LIU; Nan HU; Shi JIN; Can LIU; Dan MEI; Xiao-dong LIU

    2012-01-01

    Aim:Diabetes is associated with elevated serum total cholesterol level and disrupted lipoprotein subfractions.The aim of this study was to examine alterations in the tissue cholesterol contents closely related to diabetic complications.Methods:Intraperitoneal injection of streptozotocin was used to induce type 1 diabetes in adult male Sprague-Dawley rats.On d 35 after the injection,liver,heart,intestine,kidney,pancreas,cerebral cortex and hippocampus were isolated from the rats.The content of total and free cholesterol in the tissues was determined using HPLC.The ATP-binding cassette protein A1 (ABCA1) protein and ApoE mRNA were measured using Western blot and QT-PCR analyses,respectively.Results:In diabetic rats,the level of free cholesterol was significantly decreased in the peripheral tissues,but significantly elevated in hippocampus,as compared with those in the control rats.Diabetic rats showed a trend of decreasing the total cholesterol level in the peripheral tissues,but significant change was only found in kidney and liver.In diabetic rats,the level of the ABCA1 protein was significantly increased in the peripheral tissues and cerebral cortex; the expression of ApoE mRNA was slightly decreased in hippocampus and cerebral cortex,but the change had no statistical significance.Conclusion:Type 1 diabetes decreases the free cholesterol content in the peripheral tissues and increases the free cholesterol content in hippocampus.The decreased free cholesterol level in the peripheral tissues may be partly due to the increased expression of the ABCA1 protein.

  12. Cholesterol oxidase: sources, physical properties and analytical applications.

    Science.gov (United States)

    MacLachlan, J; Wotherspoon, A T; Ansell, R O; Brooks, C J

    2000-04-01

    Since Flegg (H.M. Flegg, An investigation of the determination of serum cholesterol by an enzymatic method, Ann. Clin. Biochem. 10 (1973) 79-84) and Richmond (W. Richmond, The development of an enzymatic technique for the assay of cholesterol in biological fluids, Scand. J. clin. Lab. Invest. 29 (1972) 25; W. Richmond, Preparation and properties of a bacterial cholesterol oxidase from Nocardia sp. and its application to enzyme assay of total cholesterol in serum, Clinical Chemistry 19 (1973) 1350-1356) first illustrated the suitability of cholesterol oxidase (COD) for the analysis of serum cholesterol, COD has risen to become the most widely used enzyme in clinical laboratories with the exception of glucose oxidase (GOD). The use is widespread because assays incorporating the enzyme are extremely simple, specific, and highly sensitive and thus offer distinct advantages over the Liebermann-Burchard analytical methodologies which employ corrosive reagents and can be prone to unreliable results due to interfering substances such as bilirubin. Individuals can now readily determine their own serum cholesterol levels with a simple disposable test kit. This review discusses COD in some detail and includes the topics: (1) The variety of bacterial sources available; (2) The various extraction/purification protocols utilised in order to obtain protein of sufficient clarification (purity) for use in food/clinical analysis; (3) Significant differences in the properties of the individual enzymes; (4) Substrate specificities of the various enzymes; (5) Examples of biological assays which have employed cholesterol oxidase as an integral part of the analysis, and the various assay protocols; (6) New steroidal products of COD. This review is not a comprehensive description of published work, but is intended to provide an account of recent and current research, and should promote further interest in the application of enzymes to analytical selectivity. PMID:10822008

  13. Optimizing Conditions to Cholesterol Adsorbed with Carboxymethyl Chitosan

    OpenAIRE

    Mardiyah Kurniasih; Dwi Kartika; Riyanti Riyanti

    2016-01-01

    A research on optimizing conditions to cholesterol adsorbed have been performed. Optimization was performed by varying: contact time, adsorbent weight and temperature of the system's. A full factorial experimental design was used in this study. Characterization performed on the synthesized chitosan and carboxymethyl chitosan including FTIR, water content, ash content, solubility, porosity, and swelling effect. The results showed that carboxymethyl chitosan able to adsorb cholesterol under con...

  14. Cholesterol depletion disorganizes oocyte membrane rafts altering mouse fertilization.

    Directory of Open Access Journals (Sweden)

    Jorgelina Buschiazzo

    Full Text Available Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-β-cyclodextrin. Cholesterol removal induced: (1 a decrease of the fertilization rate and index; and (2 a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol.

  15. HIV-Cholesterol Connection Suggests a New Antiretroviral Strategy

    OpenAIRE

    Zahedi Mujawar; Honor Rose; Morrow, Matthew P.; Tatiana Pushkarsky; Larisa Dubrovsky; Nigora Mukhamedova; Ying Fu; Anthony Dart; Orenstein, Jan M.; Bobryshev, Yuri V.; Michael Bukrinsky; Dmitri Sviridov

    2006-01-01

    Several steps of HIV-1 replication critically depend on cholesterol. HIV infection is associated with profound changes in lipid and lipoprotein metabolism and an increased risk of coronary artery disease. Whereas numerous studies have investigated the role of anti-HIV drugs in lipodystrophy and dyslipidemia, the effects of HIV infection on cellular cholesterol metabolism remain uncharacterized. Here, we demonstrate that HIV-1 impairs ATP-binding cassette transporter A1 (ABCA1)-dependent chole...

  16. Apolipoprotein M promotes mobilization of cellular cholesterol in vivo

    DEFF Research Database (Denmark)

    Elsøe, Sara; Christoffersen, Christina; Luchoomun, Jayraz;

    2013-01-01

    The HDL associated apolipoprotein M (apoM) protects against experimental atherosclerosis but the mechanism is unknown. ApoM increases prebeta-HDL formation. We explored whether plasma apoM affects mobilization of cholesterol from peripheral cells in mice.......The HDL associated apolipoprotein M (apoM) protects against experimental atherosclerosis but the mechanism is unknown. ApoM increases prebeta-HDL formation. We explored whether plasma apoM affects mobilization of cholesterol from peripheral cells in mice....

  17. Cholesterol granuloma of the right epididymis mimicking an acute scrotum

    Institute of Scientific and Technical Information of China (English)

    Borislav Spajic; Hrvoje Cupic; Goran Stimac; Ivica Brigic; Bozo Kruslin; Ognjen Kraus

    2006-01-01

    @@ Dear Sir, I am B. Spajic, the urologist from Clinical Department of Urology, Sestre Milosrdnice University Hospital,Zagreb, Croatia. Recently, we had a rare case of a cholesterol granuloma of the right epididymis at our department, showing clinical signs of acute scrotum. The case described here appears to be the second reporting cholesterol granuloma in the epididymis and the first one presenting with clinical signs of acute scrotum.

  18. Elastic deformation and failure of lipid bilayer membranes containing cholesterol.

    OpenAIRE

    Needham, D; Nunn, R. S.

    1990-01-01

    Giant bilayer vesicles were reconstituted from several lipids and lipid/cholesterol (CHOL) mixtures: stearolyloleoylphosphatidylcholine (SOPC), bovine sphingomyelin (BSM), diarachidonylphosphatidylcholine (DAPC), SOPC/CHOL, BSM/CHOL, DAPC/CHOL, and extracted red blood cell (RBC) lipids with native cholesterol. Single-walled vesicles were manipulated by micropipette suction and several membrane material properties were determined. The properties measured were the elastic area compressibility m...

  19. Emerging Roles for Cholesterol and Lipoproteins in Lung Disease

    OpenAIRE

    Gowdy, Kymberly M; Fessler, Michael B.

    2012-01-01

    Dyslipidemia, the condition of elevated serum triglycerides, elevated low-density lipoprotein cholesterol, and/or low high-density lipoprotein cholesterol, is a public health problem of growing concern. Dyslipidemia clusters with other disorders of the metabolic syndrome that together influence, and may derive from, chronic inflammation. While best recognized as a risk factor for atherosclerotic cardiovascular disease, lipid dysregulation has recently been shown to influence a variety of dise...

  20. Constraining Ceres' interior from its Rotational Motion

    CERN Document Server

    Rambaux, Nicolas; Dehant, Véronique; Kuchynka, Petr

    2011-01-01

    Context. Ceres is the most massive body of the asteroid belt and contains about 25 wt.% (weight percent) of water. Understanding its thermal evolution and assessing its current state are major goals of the Dawn Mission. Constraints on internal structure can be inferred from various observations. Especially, detailed knowledge of the rotational motion can help constrain the mass distribution inside the body, which in turn can lead to information on its geophysical history. Aims. We investigate the signature of the interior on the rotational motion of Ceres and discuss possible future measurements performed by the spacecraft Dawn that will help to constrain Ceres' internal structure. Methods. We compute the polar motion, precession-nutation, and length-of-day variations. We estimate the amplitudes of the rigid and non-rigid response for these various motions for models of Ceres interior constrained by recent shape data and surface properties. Results. As a general result, the amplitudes of oscillations in the r...

  1. Towards weakly constrained double field theory

    Science.gov (United States)

    Lee, Kanghoon

    2016-08-01

    We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon) transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  2. Towards Weakly Constrained Double Field Theory

    CERN Document Server

    Lee, Kanghoon

    2015-01-01

    We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon) transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X- ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  3. Towards weakly constrained double field theory

    Directory of Open Access Journals (Sweden)

    Kanghoon Lee

    2016-08-01

    Full Text Available We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  4. Continuation of Sets of Constrained Orbit Segments

    DEFF Research Database (Denmark)

    Schilder, Frank; Brøns, Morten; Chamoun, George Chaouki;

    Sets of constrained orbit segments of time continuous flows are collections of trajectories that represent a whole or parts of an invariant set. A non-trivial but simple example is a homoclinic orbit. A typical representation of this set consists of an equilibrium point of the flow and a trajectory...... that starts close and returns close to this fixed point within finite time. More complicated examples are hybrid periodic orbits of piecewise smooth systems or quasi-periodic invariant tori. Even though it is possible to define generalised two-point boundary value problems for computing sets of...... constrained orbit segments, this is very disadvantageous in practice. In this talk we will present an algorithm that allows the efficient continuation of sets of constrained orbit segments together with the solution of the full variational problem....

  5. The Role of Cholesterol in Driving IAPP-Membrane Interactions.

    Science.gov (United States)

    Sciacca, Michele F M; Lolicato, Fabio; Di Mauro, Giacomo; Milardi, Danilo; D'Urso, Luisa; Satriano, Cristina; Ramamoorthy, Ayyalusamy; La Rosa, Carmelo

    2016-07-12

    Our knowledge of the molecular events underlying type 2 diabetes mellitus-a protein conformational disease characterized by the aggregation of islet amyloid polypeptide (IAPP) in pancreatic β cells-is limited. However, amyloid-mediated membrane damage is known to play a key role in IAPP cytotoxicity, and therefore the effects of lipid composition on modulating IAPP-membrane interactions have been the focus of intense research. In particular, membrane cholesterol content varies with aging and consequently with adverse environmental factors such as diet and lifestyle, but its role in the development of the disease is controversial. In this study, we employ a combination of experimental techniques and in silico molecular simulations to shed light on the role of cholesterol in IAPP aggregation and the related membrane disruption. We show that if anionic POPC/POPS vesicles are used as model membranes, cholesterol has a negligible effect on the kinetics of IAPP fibril growth on the surface of the bilayer. In addition, cholesterol inhibits membrane damage by amyloid-induced poration on membranes, but enhances leakage through fiber growth on the membrane surface. Conversely, if 1:2 DOPC/DPPC raft-like model membranes are used, cholesterol accelerates fiber growth. Next, it enhances pore formation and suppresses fiber growth on the membrane surface, leading to leakage. Our results highlight a twofold effect of cholesterol on the amyloidogenicity of IAPP and help explain its debated role in type 2 diabetes mellitus. PMID:27410742

  6. Anaerobic oxidation of cholesterol by a denitrifying enrichment.

    Science.gov (United States)

    Barrandeguy, E; Tarlera, S

    2001-01-01

    Sterols (e.g. cholesterol) present in wool scouring effluent represent the most recalcitrant fraction in anaerobic treatment. This study was conducted to examine the feasibility of removal of this organic load through a denitrifying post-treatment stage. A stable cholesterol-denitrifying enrichment (CHOL-1) was obtained from sludge of a bench-scale upflow sludge bed (USB) denitrifying reactor integrated to a carbon and nitrogen removal system for sanitary landfill leachate. According to the amounts of cholesterol degraded and of nitrite and nitrogen gas formed, the capacity for complete cholesterol oxidation under anaerobic conditions by CHOL-1 can be assumed. Nitrite accumulation observed at a low C/N ratio outlines the importance of determining the optimal C/N ratio for adequate denitrifying reactor performance. The enrichment was partly identified with molecular analysis of cloned 16S rDNA sequences revealing the presence of two groups of bacteria belonging to the beta subclass of the Proteobacteria. According to analysis of sequences, it can be inferred that a yet uncultivated new bacterium is the one responsible for cholesterol oxidation. Results of this study suggest that sludge from a denitrifying reactor treating leachate is potentially useful in a combined anaerobic-anoxic system for degradation of cholesterol that remains after methanogenic treatment. PMID:11575077

  7. Cholesterol-dependent hemolytic activity of Passiflora quadrangularis leaves

    Directory of Open Access Journals (Sweden)

    L.N. Yuldasheva

    2005-07-01

    Full Text Available Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.

  8. Constrained instanton and black hole creation

    Institute of Scientific and Technical Information of China (English)

    WU; Zhongchao; XU; Donghui

    2004-01-01

    A gravitational instanton is considered as the seed for the creation of a universe. However, there exist too few instantons. To include many interesting phenomena in the framework of quantum cosmology, the concept of constrained gravitational instanton is inevitable. In this paper we show how a primordial black hole is created from a constrained instanton. The quantum creation of a generic black hole in the closed or open background is completely resolved. The relation of the creation scenario with gravitational thermodynamics and topology is discussed.

  9. Weighted Constrained Egalitarianism in TU-Games

    OpenAIRE

    Koster, M.A.L.

    1999-01-01

    The constrained egalitarian solution of Dutta and Ray (1989) for TU-games is extended to asymmetric cases, using the notion of weight systems as in Kalai and Samet (1987,1988). This weighted constrained egalitarian solution is based on the weighted Lorenz-criterion as an inequality measure. It is shown that in general there is at most one such weighted egalitarian solution for TU-games. Existence is proved for the class of convex games. Furthermore, the core of a postive valued convex game is...

  10. Constraining Initial Vacuum by CMB Data

    CERN Document Server

    Chandra, Debabrata

    2016-01-01

    We demonstrate how one can possibly constrain the initial vacuum using CMB data. Using a generic vacuum without any particular choice a priori, thereby keeping both the Bogolyubov coefficients in the analysis, we compute observable parameters from two- and three-point correlation functions. We are thus left with constraining four model parameters from the two complex Bogolyubov coefficients. We also demonstrate a method of finding out the constraint relations between the Bogolyubov coefficients using the theoretical normalization condition and observational data of power spectrum and bispectrum from CMB. We also discuss the possible pros and cons of the analysis.

  11. Murder and Self-constrained Modernity

    DEFF Research Database (Denmark)

    Hansen, Kim Toft

    Fracture”, 1999) deals with an unexplainable metaphysical horror. This short story employs a certain tragic sensibility to the narrative which no longer is a stranger to crime fiction. Arne Dahl utilizes Aeschylus’ The Oresteia which goes for two episodes of the Danish TV-series Rejseholdet (Unit One, 2002...... this paper I will approach an explanation from the point of view of what the Danish philosopher Hans Jørgen Schanz calls the self-constrained modernity: Modernity has come to realize – he explicates – that it cannot provide complete explanations of reality and, thus, it becomes self-constrained. This...

  12. Ensemble and constrained clustering with applications

    OpenAIRE

    Abdala, D.D. (Daniel)

    2011-01-01

    Diese Arbeit stellt neue Entwicklungen in Ensemble und Constrained Clustering vor und enthält die folgenden wesentlichen Beiträge: 1) Eine Vereinigung von Constrained und Ensemble Clustering in einem einheitlichen Framework. 2) Eine neue Methode zur Messung und Visualisierung der Variabilität von Ensembles. 3) Ein neues, Random Walker basiertes Verfahren für Ensemble Clustering. 4) Anwendung von Ensemble Clustering für Bildsegmentierung. 5) Eine neue Consensus-Funktion für das Ensemble Cluste...

  13. Effect of Moderate Alcohol Consumption on Parameters of Reverse Cholesterol Transport in Postmenopausal Women

    NARCIS (Netherlands)

    Sierksma, A.; Vermunt, S.H.F.; Lankhuizen, I.M.; Gaag, M.S. van der; Scheek, L.M.; Grobbee, D.E.; Tol, A. van; Hendriks, H.F.J.

    2004-01-01

    Background: Alcohol consumption is associated with increased high-density lipoprotein (HDL) cholesterol levels. One of the main antiatherogenic functions of HDL is reverse cholesterol transport. Three early steps of reverse cholesterol transport are (1) cellular cholesterol efflux, (2) plasma choles

  14. Trans-intestinal cholesterol effl ux is not mediated through high density lipoprotein

    NARCIS (Netherlands)

    Vrins, C.L.; Ottenhoff, R.; Oever, K. van den; Waart, D.R. de; Kruyt, J.K.; Zhao, Y.; Berkel, T.J. van; Havekes, L.M.; Aerts, J.M.; Eck, M. van; Rensen, P.C.; Groen, A.K.

    2012-01-01

    Transintestinal cholesterol efflux (TICE) provides an attractive target to increase body cholesterol excretion. At present, the cholesterol donor responsible for direct delivery of plasma cholesterol to the intestine is unknown. In this study, we investigated the role of HDL in TICE. ATP-binding cas

  15. LCAT, HDL Cholesterol and Ischemic Cardiovascular Disease: A Mendelian Randomization Study of HDL Cholesterol in 54,500 Individuals

    DEFF Research Database (Denmark)

    Haase, Christiane L; Tybjærg-Hansen, Anne; Ali Qayyum, Abbas;

    2012-01-01

    Background:Epidemiologically, high-density lipoprotein (HDL) cholesterol levels associate inversely with risk of ischemic cardiovascular disease. Whether this is a causal relation is unclear.Methods:We studied 10,281 participants in the Copenhagen City Heart Study (CCHS) and 50,523 participants in...... the Copenhagen General Population Study (CGPS), of which 991 and 1,693 participants, respectively, had developed myocardial infarction (MI) by August 2010. Participants in the CCHS were genotyped for all six variants identified by resequencing lecithin-cholesterol acyltransferase in 380 individuals....... One variant, S208T (rs4986970, allele frequency 4%), associated with HDL cholesterol levels in both the CCHS and the CGPS was used to study causality of HDL cholesterol using instrumental variable analysis.Results:Epidemiologically, in the CCHS, a 13% (0.21 mmol/liter) decrease in plasma HDL...

  16. Atorvastatin treatment lowers fasting remnant-like particle cholesterol and LDL subfraction cholesterol without affecting LDL size in type 2 diabetes mellitus : Relevance for non-HDL cholesterol and apolipoprotein B guideline targets

    NARCIS (Netherlands)

    Kappelle, Paul J. W. H.; Dallinga-Thie, Geesje M.; Dullaart, Robin P. F.

    2010-01-01

    The extent to which atorvastatin treatment affects LDL size, LDL subfraction levels and remnant-like particle cholesterol (RLP-C) was determined in type 2 diabetes. We also compared LDL size and RLP-C in relation to guideline cut-off values for LDL cholesterol, non-HDL cholesterol and apolipoprotein

  17. Effects of lovastatin and dietary cholesterol on sterol homeostasis in healthy human subjects.

    OpenAIRE

    Duane, W C

    1993-01-01

    We measured biliary and fecal sterol outputs in 12 human subjects on a metabolic ward in four randomly allocated, 6-7 wk periods: (a) lovastatin (40 mg b.i.d.) + low cholesterol diet (mean 246 mg/d), (b) lovastatin + high cholesterol diet (mean 1,071 mg/d), (c) low cholesterol diet alone, (d) high cholesterol diet alone. In addition to lowering serum LDL cholesterol, lovastatin significantly lowered biliary secretion of cholesterol, fecal output of endogenous neutral sterols, cholesterol bala...

  18. The origin of cholesterol in chyle demonstrated by nuclear indicator methods

    International Nuclear Information System (INIS)

    In order to obtain information about the mechanism of the intestinal absorption of cholesterol, rats having a lymphatic abdominal fistula are used. The animals receive either 4-14C- cholesterol subcutaneously or orally, or the 1-14C acetate. The study of the specific radio-activities of the cholesterol in chyle, in serum, in the lining, and in the intestinal contents makes it possible to define the roles played by the transfer cholesterol from the serum, by the cholesterol synthesised intestinally, and by the absorption cholesterol, in the formations of the lymph and of the chylomicrons. A new theory is proposed for the mechanism of cholesterol absorption. (author)

  19. How cholesterol interacts with membrane proteins: an exploration of cholesterol-binding sites including CRAC, CARC, and tilted domains

    OpenAIRE

    Fantini, Jacques; Barrantes, Francisco J.

    2013-01-01

    The plasma membrane of eukaryotic cells contains several types of lipids displaying high biochemical variability in both their apolar moiety (e.g., the acyl chain of glycerolipids) and their polar head (e.g., the sugar structure of glycosphingolipids). Among these lipids, cholesterol is unique because its biochemical variability is almost exclusively restricted to the oxidation of its polar −OH group. Although generally considered the most rigid membrane lipid, cholesterol can adopt a broad r...

  20. Lecithin:Cholesterol Acyltransferase (LCAT) Deficiency Promotes Differentiation of Satellite Cells to Brown Adipocytes in a Cholesterol-dependent Manner.

    Science.gov (United States)

    Nesan, Dinushan; Tavallaee, Ghazaleh; Koh, Deborah; Bashiri, Amir; Abdin, Rawand; Ng, Dominic S

    2015-12-18

    Our laboratory previously reported that lecithin:cholesterol acyltransferase (LCAT) and LDL receptor double knock-out mice (Ldlr(-/-)xLcat(-/-) or DKO) spontaneously develop functioning ectopic brown adipose tissue (BAT) in skeletal muscle, putatively contributing to protection from the diet-induced obesity phenotype. Here we further investigated their developmental origin and the mechanistic role of LCAT deficiency. Gene profiling of skeletal muscle in DKO newborns and adults revealed a classical lineage. Primary quiescent satellite cells (SC) from chow-fed DKO mice, not in Ldlr(-/-)xLcat(+/+) single-knock-out (SKO) or C57BL/6 wild type, were found to (i) express exclusively classical BAT-selective genes, (ii) be primed to express key functional BAT genes, and (iii) exhibit markedly increased ex vivo adipogenic differentiation into brown adipocytes. This gene priming effect was abrogated upon feeding the mice a 2% high cholesterol diet in association with accumulation of excess intracellular cholesterol. Ex vivo cholesterol loading of chow-fed DKO SC recapitulated the effect, indicating that cellular cholesterol is a key regulator of SC-to-BAT differentiation. Comparing adipogenicity of Ldlr(+/+)xLcat(-/-) (LCAT-KO) SC with DKO SC identified a role for LCAT deficiency in priming SC to express BAT genes. Additionally, we found that reduced cellular cholesterol is important for adipogenic differentiation, evidenced by increased induction of adipogenesis in cholesterol-depleted SC from both LCAT-KO and SKO mice. Taken together, we conclude that ectopic BAT in DKO mice is classical in origin, and its development begins in utero. We further showed complementary roles of LCAT deficiency and cellular cholesterol reduction in the SC-to-BAT adipogenesis. PMID:26494623

  1. Binding of fluorescently labeled cholera toxin subunit B to glycolipids in the human submandibular gland and inhibition of binding by periodate oxidation and by galactose

    DEFF Research Database (Denmark)

    Kirkeby, S

    2016-01-01

    remained unaffected even after increased oxidation. Staining with the subunit was also reduced significantly by adding galactose to the incubation medium. Binding of CTB to cell surfaces apparently requires intact sialic groups on most, but not all, cell surfaces. Oxidation of the sialic acid residues may...... influence the structure of the sialylated GM1 molecules on the cell surface in different ways. It is possible that both the sialic acid residue and the terminal galactose are oxidized. Alternatively, the sialic acid may be resistant to acid hydrolysis in gangliosides in which the sialic acid is attached to...... the internal galactose residue linked to GalNAc, as in the GM1 glycolipid. Inhibition of the GM1 receptor binding to cholera toxin has potential for protection of humans against cholera. Galactose and agents that modify sialic acid inhibit the accessibility of the toxin to the GM1 carbohydrate...

  2. Structure-function analysis of the ATP-driven glycolipid efflux pump DevBCA reveals complex organization with TolC/HgdD.

    Science.gov (United States)

    Staron, Peter; Forchhammer, Karl; Maldener, Iris

    2014-01-31

    In Gram-negative bacteria, trans-envelope efflux pumps have periplasmic membrane fusion proteins (MFPs) as essential components. MFPs act as mediators between outer membrane factors (OMFs) and inner membrane factors (IMFs). In this study, structure-function relations of the ATP-driven glycolipid efflux pump DevBCA-TolC/HgdD from the cyanobacterium Anabaena sp. PCC 7120 were analyzed. The binding of the MFP DevB to the OMF TolC absolutely required the respective tip-regions. The interaction of DevB with the IMF DevAC mainly involved the β-barrel and the lipoyl domain. Efficient binding to DevAC and TolC, substrate recognition and export activity by DevAC were dependent on stable DevB hexamers. PMID:24361095

  3. Hydrophobic ionic liquid immoblizing cholesterol oxidase on the electrodeposited Prussian blue on glassy carbon electrode for detection of cholesterol

    International Nuclear Information System (INIS)

    A novel cholesterol biosensor was fabricated on hydrophobic ionic liquid (IL)/aqueous solution interface. The hydrophobic IL thin film played a signal amplification role because it not only enriched the cholesterol from the aqueous solution, but also immobilized matrix for cholesterol oxidase (ChOx). Prussian blue (PB) as advanced sensing materials was used as effective low-potential electron transfer mediation toward hydrogen peroxide (H2O2). The fabricated IL-ChOx/PB/Glassy carbon electrode (GCE) was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammogram (CV), respectively. And it exhibited a linear response to cholesterol in the range of 0.01–0.40 mM with a detection limit of 4.4 μM. In addition, the kinetics behavior of cholesterol at IL-Chox/PB/GCE electrode was examined, and the electrocatalytic mechanism was proposed as shown in first scheme. ChOx immobilized in hydrophobic IL thin film was used as the first electrocatalyst for the cholesterol into H2O2, and the PB film onto the GCE was used as the second electrocatalyst for the 2e− reduction of the produced H2O2 into H2O

  4. Structural characterization and surface-active properties of a new glycolipid biosurfactant, mono-acylated mannosylerythritol lipid, produced from glucose by Pseudozyma antarctica.

    Science.gov (United States)

    Fukuoka, Tokuma; Morita, Tomotake; Konishi, Masaaki; Imura, Tomohiro; Sakai, Hideki; Kitamoto, Dai

    2007-09-01

    Mannosylerythritol lipids (MELs), which are glycolipid biosurfactants produced by Pseudozyma yeasts, show not only excellent interfacial properties but also versatile biochemical actions. In the course of MEL production from glucose as the sole carbon source, P. antarctica was found to produce unknown glycolipids more hydrophilic than conventional "di-acylated MELs," which have two fatty acyl esters on the mannose moiety. Based on a detailed characterization, the most hydrophilic one was identified as 4-O-(3'-O-alka(e)noyl-beta-D: -mannopyranosyl)-D: -erythritol namely, "mono-acylated MEL." The mono-acylated MEL reduced the surface tension of water to 33.8 mN/m at a critical micelle concentration (CMC) of 3.6 x 10(-4) M, and its hydrophilic-lipophilic balance was tentatively calculated to be 12.15. The observed CMC was 100-fold higher than that of the MELs hitherto reported. Interestingly, of the yeast strains of the genus Pseudozyma, only P. antarctica and P. parantarctica gave the mono-acylated MEL from glucose, despite a great diversity of di-acylated MEL producers in the genus. These strains produced MELs including the mono-acylated one at a rate of 20-25%. From these results, the new MEL is likely to have great potential for use in oil-in-water-type emulsifiers and washing detergents because of its higher water solubility compared to conventional MELs and will thus contribute to facilitating a broad range of applications for the environmentally advanced surfactants. PMID:17607573

  5. General Relativity as a constrained Gauge Theory

    OpenAIRE

    Cianci, R.; Vignolo, S.; Bruno, D

    2006-01-01

    The formulation of General Relativity presented in math-ph/0506077 and the Hamiltonian formulation of Gauge theories described in math-ph/0507001 are made to interact. The resulting scheme allows to see General Relativity as a constrained Gauge theory.

  6. Integrating job scheduling and constrained network routing

    DEFF Research Database (Denmark)

    Gamst, Mette

    2010-01-01

    This paper examines the NP-hard problem of scheduling jobs on resources such that the overall profit of executed jobs is maximized. Job demand must be sent through a constrained network to the resource before execution can begin. The problem has application in grid computing, where a number of...

  7. INSTRUMENT CHOICE AND BUDGET-CONSTRAINED TARGETING

    OpenAIRE

    Horan, Richard D.; Claassen, Roger; Agapoff, Jean; Zhang, Wei

    2004-01-01

    We analyze how choosing to use a particular type of instrument for agri-environmental payments, when these payments are constrained by the regulatory authority's budget, implies an underlying targeting criterion with respect to costs, benefits, participation, and income, and the tradeoffs among these targeting criteria. The results provide insight into current policy debates.

  8. Neutron Powder Diffraction and Constrained Refinement

    DEFF Research Database (Denmark)

    Pawley, G. S.; Mackenzie, Gordon A.; Dietrich, O. W.

    1977-01-01

    The first use of a new program, EDINP, is reported. This program allows the constrained refinement of molecules in a crystal structure with neutron diffraction powder data. The structures of p-C6F4Br2 and p-C6F4I2 are determined by packing considerations and then refined with EDINP. Refinement...

  9. Nonlinear wave equations and constrained harmonic motion

    OpenAIRE

    Deift, Percy; Lund, Fernando; Trubowitz, Eugene

    1980-01-01

    The study of the Korteweg-deVries, nonlinear Schrödinger, Sine-Gordon, and Toda lattice equations is simply the study of constrained oscillators. This is likely to be true for any nonlinear wave equation associated with a second-order linear problem.

  10. Selective delipidation of plasma HDL enhances reverse cholesterol transport in vivo

    OpenAIRE

    Sacks, Frank M.; Rudel, Lawrence L.; Conner, Adam; Akeefe, Hassibullah; Kostner, Gerhard; Baki, Talal; Rothblat, George; de la Llera-Moya, Margarita; Asztalos, Bela; Perlman, Timothy; Zheng, Chunyu; Alaupovic, Petar; Maltais, Jo-Ann B.; Brewer, H. Bryan

    2009-01-01

    Uptake of cholesterol from peripheral cells by nascent small HDL circulating in plasma is necessary to prevent atherosclerosis. This process, termed reverse cholesterol transport, produces larger cholesterol-rich HDL that transfers its cholesterol to the liver facilitating excretion. Most HDL in plasma is cholesterol-rich. We demonstrate that treating plasma with a novel selective delipidation procedure converts large to small HDL [HDL-selectively delipidated (HDL-sdl)]. HDL-sdl contains seve...

  11. Lack of Cholesterol Awareness among Physicians Who Smoke

    Directory of Open Access Journals (Sweden)

    Richard E. Scranton

    2009-02-01

    Full Text Available Cigarette use is a known risk factor for the development of coronary artery disease (CAD as it adversely affects HDL cholesterol levels and promotes thrombogenesis. Smoking may also be associated with behavioral characteristics that potentiate the risk of CAD. A lack of cholesterol knowledge would indicate an aversion to a prevention-oriented lifestyle. Thus, our goal was to determine the association between tobacco use and knowledge of self-reported cholesterol among male physicians. Using the 1982 and follow-up questionnaires from the physician health study, we report the changes in the frequencies of awareness of self-reported total cholesterol and cardiovascular risk factors among the 22,067 participants. We classified physicians as being aware of their cholesterol if they reported a cholesterol level and unaware if the question was left unanswered. In 1997, 207 physicians were excluded, as the recorded cholesterol was not interpretable, leaving 21,860 for our follow up analyses. Using unadjusted logistic models, we determined the odds ratios (OR and 95% confidence intervals (CI of not reporting a cholesterol level in either 1982 or 1997 for each specified risk factor. We then evaluated whether the lack of cholesterol awareness at both time points was associated with the use of tobacco throughout the study. After 14-years of follow up, cholesterol awareness increased from 35.9 to 58.6 percent. During this period, the frequency of hypertension and hyperlipidemia treatment increased (13.5 to 40.5% and 0.57% to 19.6% respectively, as did the diagnosis of diabetes (2.40 to 7.79%. Behavioral characteristics such as a sedentary lifestyle and obesity also increased (27.8 to 42% and 43.5 to 53.5%, respectively, however the proportion of current smokers deceased from 11.1 to 4.05%. The percentages of individuals being unaware of their cholesterol decreased in all risk factor groups. However, individuals were likely to be unaware of their cholesterol

  12. Monomethylarsonous acid inhibited endogenous cholesterol biosynthesis in human skin fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Lei [Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521-0403 (United States); Xiao, Yongsheng [Department of Chemistry, University of California, Riverside, CA 92521-0403 (United States); Wang, Yinsheng, E-mail: yinsheng.wang@ucr.edu [Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521-0403 (United States); Department of Chemistry, University of California, Riverside, CA 92521-0403 (United States)

    2014-05-15

    Human exposure to arsenic in drinking water is a widespread public health concern, and such exposure is known to be associated with many human diseases. The detailed molecular mechanisms about how arsenic species contribute to the adverse human health effects, however, remain incompletely understood. Monomethylarsonous acid [MMA(III)] is a highly toxic and stable metabolite of inorganic arsenic. To exploit the mechanisms through which MMA(III) exerts its cytotoxic effect, we adopted a quantitative proteomic approach, by coupling stable isotope labeling by amino acids in cell culture (SILAC) with LC-MS/MS analysis, to examine the variation in the entire proteome of GM00637 human skin fibroblasts following acute MMA(III) exposure. Among the ∼ 6500 unique proteins quantified, ∼ 300 displayed significant changes in expression after exposure with 2 μM MMA(III) for 24 h. Subsequent analysis revealed the perturbation of de novo cholesterol biosynthesis, selenoprotein synthesis and Nrf2 pathways evoked by MMA(III) exposure. Particularly, MMA(III) treatment resulted in considerable down-regulation of several enzymes involved in cholesterol biosynthesis. In addition, real-time PCR analysis showed reduced mRNA levels of select genes in this pathway. Furthermore, MMA(III) exposure contributed to a distinct decline in cellular cholesterol content and significant growth inhibition of multiple cell lines, both of which could be restored by supplementation of cholesterol to the culture media. Collectively, the present study demonstrated that the cytotoxicity of MMA(III) may arise, at least in part, from the down-regulation of cholesterol biosynthesis enzymes and the resultant decrease of cellular cholesterol content. - Highlights: • MMA(III)-induced perturbation of the entire proteome of GM00637 cells is studied. • Quantitative proteomic approach revealed alterations of multiple cellular pathways. • MMA(III) inhibits de novo cholesterol biosynthesis. • MMA

  13. Ionic channels and nerve membrane lipids. Cholesterol-tetrodotoxin interaction.

    Science.gov (United States)

    Villegas, R; Barnola, F V; Camejo, G

    1970-04-01

    Experiments were carried out to investigate possible interactions of tetrodotoxin (TTX) with lipid molecules isolated from nerve fiber plasma membranes of the squid Dosidicus gigas. TTX has a highly selective ability to block the channel normally used by Na(+) to cross the axolemma during nervous impulse conduction. In order to investigate the interaction each lipid sample was spread on 5 x 10(-7)M TTX and TTX-free 0.15 M NaCl solutions adjusted to pH 7.4 with 7 x 10(-3)M phosphate buffer. The surface pressure-area diagrams of the lipid monolayers revealed that TTX interacts only with cholesterol. The expansion of the cholesterol monolayers at 5 x 10(-7)M TTX was 2 A(2)/molecule at zero pressure for the experiments at 20 degrees C and 2.5 A(2)/molecule for those at 25 degrees C. Similar results were obtained in KCl subphases. The apparent dissociation constant of the cholesterol-TTX complex calculated from dose-response experiments is 2.6 x 10(-7)M. Experiments at pH 10.1 revealed that the zwitter ionic form of TTX is less active. Experiments with cholesterol derivatives (cholesteryl acetate, cholesterol methyl ether, cholestanol, and cholestanyl acetate) indicate that for the interaction with TTX a partial negatively charged group at C-3 and a double bond between C-5 and C-6 on the steroid nucleus are required. Tetrodonic acid, a biologically inactive derivative of TTX, does not interact with cholesterol. The results lead us to propose that cholesterol is part of the Na(+) channel. PMID:5435784

  14. Measurement of rates of cholesterol synthesis using tritiated water

    International Nuclear Information System (INIS)

    Rates of sterol synthesis in various tissues commonly are assessed by assaying levels of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase on isolated microsomes or by measuring the rates of incorporation of various 14C-labeled substrates or [3H]water into cholesterol by whole cell preparations in vitro or by the tissues of the whole animal in vivo. While measurement of activities of HMG-CoA reductase or rates of incorporation of 14C-labeled substrates into cholesterol give useful relative rates of sterol production, neither method yields absolute rates of cholesterol synthesis. The use of [3H]water circumvents the problem of variable and unknown dilution of the specific activity of the precursor pool encountered when 14C-labeled substrates are used and does yield absolute rates of cholesterol synthesis provided that the 3H/C incorporation ratio is known for a particular tissue. In 12 different experimental situations it has been found that from 21 to 27 micrograms atoms of 3H are incorporated into cholesterol from [3H]water in different tissues of several animal species, so that the 3H/C incorporation ratio is similar under nearly all experimental conditions and varies from 0.78 to 1.00. When administered in vivo, [3H]water rapidly equilibrates with intracellular water and is incorporated into sterols within the various organs at rates that are linear with respect to time. From such data it is possible to obtain absolute rates of cholesterol synthesis in the whole animal and in the various organs of the animal. Current data suggest, therefore, that use of [3H]water yields the most accurate rates of cholesterol synthesis both in vitro and in vivo

  15. Monomethylarsonous acid inhibited endogenous cholesterol biosynthesis in human skin fibroblasts

    International Nuclear Information System (INIS)

    Human exposure to arsenic in drinking water is a widespread public health concern, and such exposure is known to be associated with many human diseases. The detailed molecular mechanisms about how arsenic species contribute to the adverse human health effects, however, remain incompletely understood. Monomethylarsonous acid [MMA(III)] is a highly toxic and stable metabolite of inorganic arsenic. To exploit the mechanisms through which MMA(III) exerts its cytotoxic effect, we adopted a quantitative proteomic approach, by coupling stable isotope labeling by amino acids in cell culture (SILAC) with LC-MS/MS analysis, to examine the variation in the entire proteome of GM00637 human skin fibroblasts following acute MMA(III) exposure. Among the ∼ 6500 unique proteins quantified, ∼ 300 displayed significant changes in expression after exposure with 2 μM MMA(III) for 24 h. Subsequent analysis revealed the perturbation of de novo cholesterol biosynthesis, selenoprotein synthesis and Nrf2 pathways evoked by MMA(III) exposure. Particularly, MMA(III) treatment resulted in considerable down-regulation of several enzymes involved in cholesterol biosynthesis. In addition, real-time PCR analysis showed reduced mRNA levels of select genes in this pathway. Furthermore, MMA(III) exposure contributed to a distinct decline in cellular cholesterol content and significant growth inhibition of multiple cell lines, both of which could be restored by supplementation of cholesterol to the culture media. Collectively, the present study demonstrated that the cytotoxicity of MMA(III) may arise, at least in part, from the down-regulation of cholesterol biosynthesis enzymes and the resultant decrease of cellular cholesterol content. - Highlights: • MMA(III)-induced perturbation of the entire proteome of GM00637 cells is studied. • Quantitative proteomic approach revealed alterations of multiple cellular pathways. • MMA(III) inhibits de novo cholesterol biosynthesis. • MMA

  16. Prenatal Ethanol Exposure Up-Regulates the Cholesterol Transporters ATP-Binding Cassette A1 and G1 and Reduces Cholesterol Levels in the Developing Rat Brain

    OpenAIRE

    Zhou, Chunyan; Chen, Jing; Zhang, Xiaolu; Costa, Lucio G.; Guizzetti, Marina

    2014-01-01

    Aims: Cholesterol plays a pivotal role in many aspects of brain development; reduced cholesterol levels during brain development, as a consequence of genetic defects in cholesterol biosynthesis, leads to severe brain damage, including microcephaly and mental retardation, both of which are also hallmarks of the fetal alcohol syndrome. We had previously shown that ethanol up-regulates the levels of two cholesterol transporters, ABCA1 (ATP binding cassette-A1) and ABCG1, leading to increased cho...

  17. Cholesterol metabolism changes under long-term dietary restrictions while the cholesterol homeostasis remains unaffected in the cortex and hippocampus of aging rats

    OpenAIRE

    Smiljanic, Kosara; Vanmierlo, Tim; Djordjevic, Aleksandra Mladenovic; Perovic, Milka; Ivkovic, Sanja; Luetjohann, Dieter; Kanazir, Selma

    2014-01-01

    Maintaining cholesterol homeostasis in the brain is vital for its proper functioning. While it is well documented that dietary restriction modulates the metabolism of cholesterol peripherally, little is known as to how it can affect cholesterol metabolism in the brain. The present study was designed to elucidate the impact of long-term dietary restriction on brain cholesterol metabolism. Three-month-old male Wistar rats were exposed to long-term dietary restriction until 12 and 24 months of a...

  18. Dietary Cholesterol Affects Plasma Lipid Levels, the Intravascular Processing of Lipoproteins and Reverse Cholesterol Transport without Increasing the Risk for Heart Disease

    OpenAIRE

    Jacqueline Barona; Maria Luz Fernandez

    2012-01-01

    The associations between dietary cholesterol and heart disease are highly controversial. While epidemiological studies and clinical interventions have shown the lack of correlation between cholesterol intake and cardiovascular disease (CVD) risk, there is still concern among health practitioners and the general population regarding dietary cholesterol. In this review, several clinical studies utilizing cholesterol challenges are analyzed in terms of changes that occur in lipoprotein metabolis...

  19. Chylomicron remnant model emulsions induce intracellular cholesterol accumulation and cell death due to lysosomal destabilization.

    Science.gov (United States)

    Wakita, Kyoko; Morita, Shin-ya; Okamoto, Naoko; Takata, Eriko; Handa, Tetsurou; Nakano, Minoru

    2015-05-01

    Chylomicron remnants, which carry dietary fats and cholesterol, play a role in promoting atherosclerosis. Chylomicron remnants are characterized by high cholesterol content at the surface, different from low-density lipoproteins (LDLs) containing high amounts of esterified cholesterol (CE) in the core. We prepared cholesterol-rich emulsions (TO-PC/cholesterol emulsions) as models for chylomicron remnants and compared their effects on J774 macrophages with acetylated-LDL (ac-LDL). Internalization of TO-PC/cholesterol emulsions into macrophages reduced cell viability, whereas ac-LDL did not. Surprisingly, there was no difference in intracellular free cholesterol content between cells incubated with TO-PC/cholesterol emulsions and with ac-LDL. Furthermore, cholesterol in TO-PC/cholesterol emulsions and ac-LDL both were internalized into J774 macrophages; however, incubation with TO-PC/cholesterol emulsions induced leakage of lysosomal protease, cathepsin-L, to cytosol, which was not observed for incubation with ac-LDL. Inhibition of the activity of cathepsin-L recovered the viability of macrophages that ingested TO-PC/cholesterol emulsions. We suggest an alternative fate of cholesterol-rich emulsions taken up by macrophages, which is different from other atherogenic lipoproteins rich in CE; internalization of TO-PC/cholesterol emulsions into macrophages induces rapid free cholesterol accumulation in lysosomes and cell death due to lysosomal destabilization. PMID:25661161

  20. The mechanism of dietary cholesterol effects on lipids metabolism in rats

    Directory of Open Access Journals (Sweden)

    Wang Jing-Feng

    2010-01-01

    Full Text Available Abstract Background Cholesterol administration has been reported to influence hepatic lipid metabolism in rats. In the present study, the effect of dietary cholesterol on hepatic activity and mRNA expression of the enzymes involved in lipid metabolism were investigated. Fourteen male Wistar rats were randomly divided into 2 groups and fed 1% cholesterol or cholesterol free AIN76 diets for 4 weeks. Results The serum triglyceride and high density lipoprotein cholesterol levels were significantly decreased but the total cholesterol and non high density lipoprotein cholesterol levels were significantly increased in the cholesterol-fed rats compared with the control rats. And the concentrations of the hepatic total cholesterol and triglyceride increased about 4-fold and 20-fold separately by dietary cholesterol. The activities of hepatic malic enzyme, glucose-6-phosphate dehydrogenase, fatty acid synthase, phosphatidate phophatase and carnitine palmitoyl transferase were depressed by the cholesterol feeding (40%, 70%, 50%, 15% and 25% respectively. The results of mRNA expression showed that fatty acid synthase, carnitine palmitoyl transferase 1, carnitine palmitoyl transferase 2, and HMG-CoA reductase were down-regulated (35%, 30%, 50% and 25% respectively and acyl-CoA: cholesterol acyltransferase and cholesterol 7α-hydroxylase were up regulated (1.6 and 6.5 folds in liver by the cholesterol administration. Conclusions The dietary cholesterol increased the triglyceride accumulation in liver, but did not stimulate the activity and the gene expression of hepatic enzymes related to triglyceride and fatty acid biosynthesis.