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Sample records for acyl-coenzyme a-dependent lysophosphatidic

  1. Acyl-coenzyme A binding protein (ACBP)

    DEFF Research Database (Denmark)

    Kragelund, B B; Knudsen, J; Poulsen, F M

    1999-01-01

    Acyl-coenzyme A binding proteins are known from a large group of eukaryote species and to bind a long chain length acyl-CoA ester with very high affinity. Detailed biochemical mapping of ligand binding properties has been obtained as well as in-depth structural studies on the bovine apo-protein a...

  2. Acyl-coenzyme A organizes laterally in membranes and is recognized specifically by acyl-coenzyme A binding protein

    DEFF Research Database (Denmark)

    Cohen Simonsen, A; Bernchou Jensen, U; Færgeman, Nils J.

    2003-01-01

    Long chain acyl-coenzyme A (acyl-CoA) is a biochemically important amphiphilic molecule that is known to partition strongly into membranes by insertion of the acyl chain. At present, microscopically resolved evidence is lacking on how acyl-CoA influences and organizes laterally in membranes. By a...

  3. Acyl coenzyme A carboxylase of Propionibacterium shermanii: detection and properties.

    Science.gov (United States)

    Stirling, L A; Ahmad, P M; Ahmad, F

    1981-01-01

    An acyl coenzyme A (CoA) carboxylase, which catalyzes the adenosine triphosphate-dependent fixation of CO2 into acetyl-, propionyl-, and butyryl-CoA, was detected in fractionated cell extracts of Propionibacterium shermanii. Catalytic activity was inhibited by avidin but was unaffected by avidin pretreated with excess biotin. The carboxylase levels detected were relatively small and were related to cellular growth. Maximal carboxylase activity was detected in cells grown for about 96 h. Thereafter, the activity declined rapidly. Optimal CO2 fixation occurred at pH 7.5. Other parameters of the assay system were optimized, and the apparent Km values for substrates were determined. The end product of the reaction (with acetyl-CoA as the substrate) was identified as malonyl-CoA. The stoichiometry of the reaction was such that, for every mole of acetyl-CoA and adenosine triphosphate consumed, 1 mol each of malonyl-CoA, adenosine diphosphate, and orthophosphate was formed. These data provide the first evidence for the presence of another biotin-containing enzyme, an acyl-CoA carboxylase, in these bacteria in addition to the well-characterized methylmalonyl-CoA carboxyltransferase. PMID:6796564

  4. Continuous recording of long-chain acyl-coenzyme A synthetase activity using fluorescently labeled bovine serum albumin

    DEFF Research Database (Denmark)

    Demant, Erland J.F.; Nystrøm, Birthe T.

    2001-01-01

    acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes......acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes...

  5. Adult peroxisomal acyl-coenzyme A oxidase deficiency with cerebellar and brainstem atrophy

    NARCIS (Netherlands)

    Ferdinandusse, S.; Barker, S.; Lachlan, K.; Duran, M.; Waterham, H.R.; Wanders, R.J.A.; Hammans, S.

    2010-01-01

    Peroxisomal acyl-coenzyme A oxidase deficiency ( formerly also called pseudoneonatal adrenoleucodystrophy) is a disorder of peroxisomal fatty acid oxidation with a severe presentation. Most patients present at birth or in early infancy, and the mean age of death was 5 years in a recently published

  6. Clinical, biochemical, and genetic heterogeneity in short-chain acyl-coenzyme A dehydrogenase deficiency

    NARCIS (Netherlands)

    van Maldegem, Bianca T.; Duran, Marinus; Wanders, Ronald J. A.; Niezen-Koning, Klary E.; Hogeveen, Marije; Ijlst, Lodewijk; Waterham, Hans R.; Wijburg, Frits A.

    2006-01-01

    Context Short-chain acyl-coenzyme A (CoA) dehydrogenase (SCAD) deficiency (SCADD) is an autosomal recessive, clinically heterogeneous disorder with only 22 case reports published so far. Screening for SCADD is included in expanded newborn screening programs in most US and Australian states.

  7. Clinical, biochemical, and genetic heterogeneity in short-chain acyl-coenzyme A dehydrogenase deficiency

    NARCIS (Netherlands)

    van Maldegem, Bianca T.; Duran, Marinus; Wanders, Ronald J. A.; Niezen-Koning, Klary E.; Hogeveen, Marije; Ijlst, Lodewijk; Waterham, Hans R.; Wijburg, Frits A.

    2006-01-01

    CONTEXT: Short-chain acyl-coenzyme A (CoA) dehydrogenase (SCAD) deficiency (SCADD) is an autosomal recessive, clinically heterogeneous disorder with only 22 case reports published so far. Screening for SCADD is included in expanded newborn screening programs in most US and Australian states.

  8. Recurrent Ventricular Tachycardia in Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency

    NARCIS (Netherlands)

    Bala, P.; Ferdinandusse, S.; Olpin, S. E.; Chetcuti, P.; Morris, A. A. M.

    2016-01-01

    We report a baby with medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency who presented on day 2 with poor feeding and lethargy. She was floppy with hypoglycaemia (1.8 mmol/l) and hyperammonaemia (182 μmol/l). Despite correction of these and a continuous intravenous infusion of glucose at

  9. Very long chain acyl-coenzyme A dehydrogenase deficiency with adult onset

    DEFF Research Database (Denmark)

    Smelt, A H; Poorthuis, B J; Onkenhout, W

    1998-01-01

    Very long chain acyl-coenzyme A (acyl-CoA) dehydrogenase (VLCAD) deficiency is a severe disorder of mitochondrial beta-oxidation in infants. We report adult onset of attacks of painful rhabdomyolysis. Gas chromatography identified strongly elevated levels of tetradecenoic acid, 14:1(n-9), tetrade......Very long chain acyl-coenzyme A (acyl-CoA) dehydrogenase (VLCAD) deficiency is a severe disorder of mitochondrial beta-oxidation in infants. We report adult onset of attacks of painful rhabdomyolysis. Gas chromatography identified strongly elevated levels of tetradecenoic acid, 14:1(n-9...... be due to residual enzyme activity as a consequence of the two missense mutations. Treatment with L-carnitine and medium chain triglycerides in the diet did not reduce the attacks of rhabdomyolysis....

  10. Engineered Production of Short-Chain Acyl-Coenzyme A Esters in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Krink-Koutsoubelis, Nicolas; Loechner, Anne C.; Lechner, Anna

    2018-01-01

    Short-chain acyl-coenzyme A esters serve as intermediate compounds in fatty acid biosynthesis, and the production of polyketides, biopolymers and other value-added chemicals. S. cerevisiae is a model organism that has been utilized for the biosynthesis of such biologically and economically valuable...... compounds. However, its limited repertoire of short-chain acyl-CoAs effectively prevents its application as a production host for a plethora of natural products. Therefore, we introduced biosynthetic metabolic pathways to five different acyl-CoA esters into S. cerevisiae. Our engineered strains provide...

  11. Prolonged QTc interval in association with medium-chain acyl-coenzyme A dehydrogenase deficiency.

    Science.gov (United States)

    Wiles, Jason R; Leslie, Nancy; Knilans, Timothy K; Akinbi, Henry

    2014-06-01

    Medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency is the most common disorder of mitochondrial fatty acid oxidation. We report a term male infant who presented at 3 days of age with hypoglycemia, compensated metabolic acidosis, hypocalcemia, and prolonged QTc interval. Pregnancy was complicated by maternal premature atrial contractions and premature ventricular contractions. Prolongation of the QTc interval resolved after correction of metabolic derangements. The newborn screen was suggestive for MCAD deficiency, a diagnosis that was confirmed on genetic analysis that showed homozygosity for the disease-associated missense A985G mutation in the ACADM gene. This is the first report of acquired prolonged QTc in a neonate with MCAD deficiency, and it suggests that MCAD deficiency should be considered in the differential diagnoses of acute neonatal illnesses associated with electrocardiographic abnormality. We review the clinical presentation and diagnosis of MCAD deficiency in neonates. Copyright © 2014 by the American Academy of Pediatrics.

  12. Fulminant lipid storage myopathy due to multiple acyl-coenzyme a dehydrogenase deficiency.

    Science.gov (United States)

    Whitaker, Charles H; Felice, Kevin J; Silvers, David; Wu, Qian

    2015-08-01

    The lipid storage myopathies, primary carnitine deficiency, neutral lipid storage disease, and multiple acyl coenzyme A dehydrogenase deficiency (MADD), are progressive disorders that cause permanent weakness. These disorders of fatty acid metabolism and intracellular triglyceride degradation cause marked fat deposition and damage to muscle cells. We describe a rapidly progressive myopathy in a previously healthy 33-year-old woman. Over 4 months, she developed a proximal and axial myopathy associated with diffuse myalgia and dysphagia, ultimately leading to respiratory failure and death. Muscle biopsy showed massive accumulation of lipid. Plasma acylcarnitine and urine organic acid analysis was consistent with MADD. This was confirmed by molecular genetic testing, which revealed 2 pathogenic mutations in the ETFDH gene. This report illustrates a late-onset case of MADD and reviews the differential diagnosis and evaluation of patients with proximal myopathy and excessive accumulation of lipid on muscle biopsy. © 2014 Wiley Periodicals, Inc.

  13. How chain length and charge affect surfactant denaturation of acyl coenzyme a binding protein (ACBP)

    DEFF Research Database (Denmark)

    Andersen, Kell; Otzen, Daniel

    2009-01-01

    Using intrinsic tryptophan fluorescence, equilibria and kinetics of unfolding of acyl coenzyme A binding protein (ACBP) have been investigated in sodium alkyl sulfate surfactants of different chain length (8-16 carbon atoms) and with different proportions of the nonionic surfactant dodecyl...... maltoside (DDM). The aim has been to determine how surfactant chain length and micellar charge affect the denaturation mechanism. ACBP denatures in two steps irrespective of surfactant chain length, but with increasing chain length, the potency of the denaturant rises more rapidly than the critical micelle...... constants increases linearly with denaturant concentration below the cmc but declines at higher concentrations. Both shortening chain length and decreasing micellar charge reduce the overall kinetics of unfolding and makes the dependence of unfolding rate constants on surfactant concentration more complex...

  14. Thermodynamics of aminoglycoside and acyl-coenzyme A binding to the Salmonella enterica AAC(6')-Iy aminoglycoside N-acetyltransferase.

    Science.gov (United States)

    Hegde, Subray S; Dam, Tarun K; Brewer, C Fred; Blanchard, John S

    2002-06-11

    Kinetic and mechanistic studies on the chromosomally encoded aminoglycoside 6'-N-acetyltransferase, AAC(6')-Iy, of Salmonella enterica that confers resistance toward aminoglycosides have been previously reported [Magnet et al. (2001) Biochemistry 40, 3700-3709]. In the present study, equilibrium binding and the thermodynamic parameters of binding of aminoglycosides and acyl-coenzyme A derivatives to AAC(6')-Iy and of two mutants, C109A and the C109A/C70A double mutant, have been studied using fluorescence spectroscopy and isothermal titration calorimetry (ITC). Association constants for different aminoglycosides varied greatly (4 x 10(4)-150 x 10(4)) while the association constants of several acyl-coenzyme A derivatives were similar (3.2 x 10(4)-4.5 x 10(4)). The association constants and van't Hoff enthalpy changes derived from intrinsic protein fluorescence changes were in agreement with independently measured values from isothermal titration calorimetry studies. Binding of both aminoglycosides and acyl-coenzyme A derivatives is strongly enthalpically driven and revealed opposing negative entropy changes, resulting in enthalpy-entropy compensation. The acetyltransferase exhibited a temperature-dependent binding of tobramycin with a negative heat capacity value of 410 cal mol(-1) K(-1). Isothermal titration studies of acetyl-coenzyme A and tobramycin binding to mutant forms of the enzyme indicated that completely conserved C109 does not play any direct role in the binding of either of the substrates, while C70 is directly involved in aminoglycoside binding. These results are discussed and compared with previous steady-state kinetic studies of the enzyme.

  15. Patients with medium-chain acyl-coenzyme a dehydrogenase deficiency have impaired oxidation of fat during exercise but no effect of L-carnitine supplementation

    DEFF Research Database (Denmark)

    Madsen, K L; Preisler, N; Orngreen, M C

    2013-01-01

    It is not clear to what extent skeletal muscle is affected in patients with medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD). l-Carnitine is commonly used as a supplement in patients with MCADD, although its beneficial effect has not been verified.......It is not clear to what extent skeletal muscle is affected in patients with medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD). l-Carnitine is commonly used as a supplement in patients with MCADD, although its beneficial effect has not been verified....

  16. Genetic basis for correction of very-long-chain acyl-coenzyme A dehydrogenase deficiency by bezafibrate in patient fibroblasts

    DEFF Research Database (Denmark)

    Gobin-Limballe, S; Djouadi, F; Aubey, F

    2007-01-01

    Very-long-chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency is an inborn mitochondrial fatty-acid beta-oxidation (FAO) defect associated with a broad mutational spectrum, with phenotypes ranging from fatal cardiopathy in infancy to adolescent-onset myopathy, and for which there is no establi......Very-long-chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency is an inborn mitochondrial fatty-acid beta-oxidation (FAO) defect associated with a broad mutational spectrum, with phenotypes ranging from fatal cardiopathy in infancy to adolescent-onset myopathy, and for which...... values, for 21 genotypes that mainly corresponded to patients with the myopathic phenotype. In contrast, bezafibrate induced no changes in FAO for 11 genotypes corresponding to severe neonatal or infantile phenotypes. This pattern of response was not due to differential inductions of VLCAD messenger RNA...... for analysis of genetic heterogeneity. Finally, this study emphasizes the potential of bezafibrate, a widely prescribed hypolipidemic drug, for the correction of VLCAD deficiency and exemplifies the integration of molecular information in a therapeutic strategy....

  17. An approach to prevent aggregation during the purification and crystallization of wild type acyl coenzyme A : Isopenicillin N acyltransferase from Penicillium chrysogenum

    NARCIS (Netherlands)

    Yoshida, Hiromi; Hensgens, Charles M.H.; Laan, Jan Metske van der; Sutherland, John D.; Hart, Darren J.; Dijkstra, Bauke W.

    2005-01-01

    Acyl coenzyme A: isopenicillin N acyltransferase (AT) from Penicillium chrysogenum is an enzyme of interest for the biosynthesis of β-lactam antibiotics. Severe aggregation problems with wild type AT have, however, prevented significant progress in the structure–function analysis of this enzyme for

  18. Genetic Basis for Correction of Very‐Long‐Chain Acyl-Coenzyme A Dehydrogenase Deficiency by Bezafibrate in Patient Fibroblasts: Toward a Genotype‐Based Therapy

    DEFF Research Database (Denmark)

    Gobin‐Limballe, S.; Djouadi, F.; Aubey, F.

    2007-01-01

    Very‐long‐chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency is an inborn mitochondrial fatty‐acid β‐oxidation (FAO) defect associated with a broad mutational spectrum, with phenotypes ranging from fatal cardiopathy in infancy to adolescent‐onset myopathy, and for which there is no established...

  19. Anesthetic agents in patients with very long-chain acyl-coenzyme A dehydrogenase deficiency: a literature review.

    Science.gov (United States)

    Redshaw, Charlotte; Stewart, Catherine

    2014-11-01

    Very long-chain acyl-coenzyme A dehydrongenase deficiency (VLCADD) is a rare disorder of fatty acid metabolism that renders sufferers susceptible to hypoglycemia, liver failure, cardiomyopathy, and rhabdomyolysis. The literature about the management of these patients is hugely conflicting, suggesting that both propofol and volatile anesthesia should be avoided. We have reviewed the literature and have concluded that the source papers do not support the statements that volatile anesthetic agents are unsafe. The reports on rhabdomyolysis secondary to anesthesia appear to be due to inadequate supply of carbohydrate not volatile agents. Catabolism must be avoided with minimal fasting, glucose infusions based on age and weight, and attenuation of emotional and physical stress. General anesthesia appears to be protective of stress-induced catabolism and may offer benefits in children and anxious patients over regional anesthesia. Propofol has not been demonstrated to be harmful in VLCADD but is presented in an emulsion containing very long-chain fatty acids which can cause organ lipidosis and itself can inhibit mitochondrial fatty acid metabolism. It is therefore not recommended. Suxamethonium-induced myalgia may mimic symptoms of rhabdomyolysis and cause raised CK therefore should be avoided. Opioids, NSAIDS, regional anesthesia, and local anesthetic techniques have all been used without complication. © 2014 John Wiley & Sons Ltd.

  20. Structure of YciA from Haemophilus influenzae (HI0827), a Hexameric Broad Specificity Acyl-Coenzyme A Thioesterase

    Energy Technology Data Exchange (ETDEWEB)

    Willis, Mark A.; Zhuang, Zhihao; Song, Feng; Howard, Andrew; Dunaway-Mariano, Debra; Herzberg, Osnat (UNM); (IIT); (UMBI)

    2008-04-02

    The crystal structure of HI0827 from Haemophilus influenzae Rd KW20, initially annotated 'hypothetical protein' in sequence databases, exhibits an acyl-coenzyme A (acyl-CoA) thioesterase 'hot dog' fold with a trimer of dimers oligomeric association, a novel assembly for this enzyme family. In studies described in the preceding paper [Zhuang, Z., Song, F., Zhao, H., Li, L., Cao, J., Eisenstein, E., Herzberg, O., and Dunaway-Mariano, D. (2008) Biochemistry 47, 2789-2796], HI0827 is shown to be an acyl-CoA thioesterase that acts on a wide range of acyl-CoA compounds. Two substrate binding sites are located across the dimer interface. The binding sites are occupied by two CoA molecules, one with full occupancy and the second only partially occupied. The CoA molecules, acquired from HI0827-expressing Escherichia coli cells, remained tightly bound to the enzyme through the protein purification steps. The difference in CoA occupancies indicates a different substrate affinity for each of the binding sites, which in turn implies that the enzyme might be subject to allosteric regulation. Mutagenesis studies have shown that the replacement of the putative catalytic carboxylate Asp44 with an alanine residue abolishes activity. The impact of this mutation is seen in the crystal structure of D44A HI0827. Whereas the overall fold and assembly of the mutant protein are the same as those of the wild-type enzyme, the CoA ligands are absent. The dimer interface is perturbed, and the channel that accommodates the thioester acyl chain is more open and wider than that observed in the wild-type enzyme. A model of intact substrate bound to wild-type HI0827 provides a structural rationale for the broad substrate range.

  1. Five Fatty Acyl-Coenzyme A Reductases Are Involved in the Biosynthesis of Primary Alcohols in Aegilops tauschii Leaves

    Directory of Open Access Journals (Sweden)

    Meiling Wang

    2017-06-01

    Full Text Available The diploid Aegilops tauschii is the D-genome donor to hexaploid wheat (Triticum aestivum and represents a potential source for genetic study in common wheat. The ubiquitous wax covering the aerial parts of plants plays an important role in protecting plants against non-stomatal water loss. Cuticular waxes are complex mixtures of very-long-chain fatty acids, alkanes, primary and/or secondary alcohols, aldehydes, ketones, esters, triterpenes, sterols, and flavonoids. In the present work, primary alcohols were identified as the major components of leaf cuticular wax in Ae. tauschii, with C26:0-OH being the dominant primary alcohol. Analysis by scanning electron microscope revealed that dense platelet-shaped wax crystals were deposited on leaf surfaces of Ae. tauschii. Ten putative wax biosynthetic genes encoding fatty acyl-coenzyme A reductase (FAR were identified in the genome of Ae. tauschii. Five of these genes, Ae.tFAR1, Ae.tFAR2, Ae.tFAR3, Ae.tFAR4, and Ae.tFAR6, were found expressed in the leaf blades. Heterologous expression of the five Ae.tFARs in yeast (Saccharomyces cerevisiae showed that Ae.tFAR1, Ae.tFAR2, Ae.tFAR3, Ae.tFAR4, and Ae.tFAR6 were predominantly responsible for the accumulation of C16:0, C18:0, C26:0, C24:0, and C28:0 primary alcohols, respectively. In addition, nine Ae.tFAR paralogous genes were located on D chromosome of wheat and the wheat nullisomic–tetrasomic lines with the loss of Ae.tFAR3 and Ae.tFAR4 paralogous genes had significantly reduced levels of primary alcohols in the leaf blades. Collectively, these data suggest that Ae.tFAR1, Ae.tFAR2, Ae.tFAR3, Ae.tFAR4, and Ae.tFAR6 encode alcohol-forming FARs involved in the biosynthesis of primary alcohols in the leaf blades of Ae. tauschii. The information obtained in Ae. tauschii enables us to better understand wax biosynthesis in common wheat.

  2. Purification of a jojoba embryo fatty acyl-coenzyme A reductase and expression of its cDNA in high erucic acid rapeseed.

    Science.gov (United States)

    Metz, J G; Pollard, M R; Anderson, L; Hayes, T R; Lassner, M W

    2000-03-01

    The jojoba (Simmondsia chinensis) plant produces esters of long-chain alcohols and fatty acids (waxes) as a seed lipid energy reserve. This is in contrast to the triglycerides found in seeds of other plants. We purified an alcohol-forming fatty acyl-coenzyme A reductase (FAR) from developing embryos and cloned the cDNA encoding the enzyme. Expression of a cDNA in Escherichia coli confers FAR activity upon those cells and results in the accumulation of fatty alcohols. The FAR sequence shows significant homology to an Arabidopsis protein of unknown function that is essential for pollen development. When the jojoba FAR cDNA is expressed in embryos of Brassica napus, long-chain alcohols can be detected in transmethylated seed oils. Resynthesis of the gene to reduce its A plus T content resulted in increased levels of alcohol production. In addition to free alcohols, novel wax esters were detected in the transgenic seed oils. In vitro assays revealed that B. napus embryos have an endogenous fatty acyl-coenzyme A: fatty alcohol acyl-transferase activity that could account for this wax synthesis. Thus, introduction of a single cDNA into B. napus results in a redirection of a portion of seed oil synthesis from triglycerides to waxes.

  3. Acyl coenzyme A synthetase long-chain 1 (ACSL1 gene polymorphism (rs6552828 and elite endurance athletic status: a replication study.

    Directory of Open Access Journals (Sweden)

    Thomas Yvert

    Full Text Available The aim of this study was to determine the association between the rs6552828 polymorphism in acyl coenzyme A synthetase (ACSL1 and elite endurance athletic status. We studied 82 Caucasian (Spanish World/Olympic-class endurance male athletes, and a group of sex and ethnically matched healthy young adults (controls, n=197. The analyses were replicated in a cohort of a different ethnic origin (Chinese of the Han ethnic group, composed of elite endurance athletes (runners [cases, n=241 (128 male] and healthy sedentary adults [controls, n=504 (267 male]. In the Spanish cohort, genotype (P=0.591 and minor allele (A frequencies were similar in cases and controls (P=0.978. In the Chinese cohort, genotype (P=0.973 and minor allele (G frequencies were comparable in female endurance athletes and sedentary controls (P=0.881, whereas in males the frequency of the G allele was higher in endurance athletes (0.40 compared with their controls (0.32, P=0.040. The odds ratio (95%CI for an elite endurance Chinese athlete to carry the G allele compared with ethnically matched controls was 1.381 (1.015-1.880 (P-value=0.04. Our findings suggest that the ACSL1 gene polymorphism rs6552828 is not associated with elite endurance athletic status in Caucasians, yet a marginal association seems to exist for the Chinese (Han male population.

  4. Recombinant adeno-associated virus-mediated gene delivery of long chain acyl coenzyme A dehydrogenase (LCAD) into LCAD-deficient mice.

    Science.gov (United States)

    Beattie, Stuart G; Goetzman, Eric; Tang, Qiuishi; Conlon, Thomas; Campbell-Thompson, Martha; Matern, Dietrich; Vockley, Jerry; Flotte, Terence R

    2008-10-01

    Very long chain acyl coenzyme A (CoA) dehydrogenase (VLCAD) deficiency is a relatively common mitochondrial beta-oxidation disorder. The most severe form of VLCAD deficiency presents with neonatal cardiomyopathy and hepatic failure and is generally fatal within the first year of life. Mice deficient for long chain acyl CoA dehydrogenase (LCAD) closely resemble the clinical syndrome observed in VLCAD-deficient humans. Recombinant adeno-associated viral (rAAV) vectors with pseudotype capsids were investigated for their potential towards correcting the phenotype observed in mice heterozygous (+/-) for LCAD (i.e. liver and muscle steatosis). rAAV containing the mouse LCAD cDNA (mLCAD) under the transcriptional control of the CMV/chicken beta-actin hybrid promoter were injected intramuscularly into the tibialis anterior (TA) muscle of LCAD(+/-) mice or injected into the portal vein to transduce hepatocytes. Ten weeks post-injection of rAAV1-mLCAD into the TA muscle, significantly increased levels of mLCAD within mitochondria were demonstrated by immunostaining of TA sections, immunoblotting of mitochondrial isolates and by the electron transfer flavoprotein (ETF) fluorescence reduction enzyme activity assay. Magnetic resonance spectroscopy of vector-injected TA muscle demonstrated a reduction in the lipid content compared to phosphate-buffered saline-injected mice, whereas a systemic effect was observed as a reduction in liver macrosteatosis. Eight weeks after portal vein injection of rAAV8-mLCAD into LCAD(+/-) mice, increased levels of mLCAD within hepatocyte mitochondria were demonstrated by immunostaining and also by the ETF assay. Scoring of the hepatosteatosis observed in partially deficient LCAD mice indicated a reduction in the lipid content within livers of vector-treated mice. These studies show that rAAV-mediated delivery of mLCAD was efficient and led to an amelioration of local and systemic pathologies observed in partially deficient LCAD mice. Copyright (c

  5. OleA Glu117 is key to condensation of two fatty-acyl coenzyme A substrates in long-chain olefin biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Matthew R.; Goblirsch, Brandon R.; Christenson, James K.; Esler, Morgan A.; Mohamed, Fatuma A.; Wackett, Lawrence P.; Wilmot, Carrie M. (UMM)

    2017-10-12

    In the interest of decreasing dependence on fossil fuels, microbial hydrocarbon biosynthesis pathways are being studied for renewable, tailored production of specialty chemicals and biofuels. One candidate is long-chain olefin biosynthesis, a widespread bacterial pathway that produces waxy hydrocarbons. Found in three- and four-gene clusters, oleABCD encodes the enzymes necessary to produce cis-olefins that differ by alkyl chain length, degree of unsaturation, and alkyl chain branching. The first enzyme in the pathway, OleA, catalyzes the Claisen condensation of two fatty acyl-coenzyme A (CoA) molecules to form a β-keto acid. In this report, the mechanistic role of Xanthomonas campestris OleA Glu117 is investigated through mutant enzymes. Crystal structures were determined for each mutant as well as their complex with the inhibitor cerulenin. Complemented by substrate modeling, these structures suggest that Glu117 aids in substrate positioning for productive carbon–carbon bond formation. Analysis of acyl-CoA substrate hydrolysis shows diminished activity in all mutants. When the active site lacks an acidic residue in the 117 position, OleA cannot form condensed product, demonstrating that Glu117 has a critical role upstream of the essential condensation reaction. Profiling of pH dependence shows that the apparent pKa for Glu117 is affected by mutagenesis. Taken together, we propose that Glu117 is the general base needed to prime condensation via deprotonation of the second, non-covalently bound substrate during turnover. This is the first example of a member of the thiolase superfamily of condensing enzymes to contain an active site base originating from the second monomer of the dimer.

  6. Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Xiaomang; Li, Danyang; Chen, Dilong; Zhou, Liang [Faculty of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016 China (China); Chonan, Ritsu [Koei Kogyo Co., Ltd., Tokyo, 101-0063 Japan (Japan); Yamahara, Johji [Pharmafood Institute, Kyoto, 602-8136 Japan (Japan); Wang, Jianwei, E-mail: wangjianwei1968@gmail.com [Department of Traditional Chinese Medicine, Chongqing Medical University, Chongqing 400016 China (China); Li, Yuhao, E-mail: yuhao@sitcm.edu.au [Endocrinology and Metabolism Group, Sydney Institute of Health Sciences/Sydney Institute of Traditional Chinese Medicine, NSW 2000 Australia (Australia)

    2014-10-15

    Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation. - Highlights: • We investigated the anti-steatotic effect of mangiferin (MA) in fructose-fed SHR. • MA (15 mg/kg/day for 7 weeks) ameliorated fructose-induced fatty liver in

  7. Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver

    International Nuclear Information System (INIS)

    Xing, Xiaomang; Li, Danyang; Chen, Dilong; Zhou, Liang; Chonan, Ritsu; Yamahara, Johji; Wang, Jianwei; Li, Yuhao

    2014-01-01

    Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation. - Highlights: • We investigated the anti-steatotic effect of mangiferin (MA) in fructose-fed SHR. • MA (15 mg/kg/day for 7 weeks) ameliorated fructose-induced fatty liver in

  8. SLC1 and SLC4 encode partially redundant acyl-coenzyme A 1-acylglycerol-3-phosphate O-acyltransferases of budding yeast

    DEFF Research Database (Denmark)

    Benghezal, Mohammed; Roubaty, Carole; Veepuri, Vijayanath

    2007-01-01

    that in vivo Slc1p and Slc4p generate almost the same glycerophospholipid profile. Microsomes from slc1Delta and slc4Delta cells incubated with [14C]oleoyl-coenzyme A in the absence of lysophosphatidic acid and without CTP still incorporate the label into glycerophospholipids, indicating that Slc1p and Slc4p...... can also use endogenous lysoglycerophospholipids as substrates. However, the lipid profiles generated by microsomes from slc1Delta and slc4Delta cells are different, and this suggests that Slc1p and Slc4p have a different substrate specificity or have access to different lyso......-glycerophospholipid substrates because of a different subcellular location. Indeed, affinity-purified Slc1p displays Mg2+-dependent acyltransferase activity not only toward lysophosphatidic acid but also lyso forms of phosphatidylserine and phosphatidylinositol. Thus, Slc1p and Slc4p may not only be active as 1-acylglycerol-3...

  9. Bioconversion of α-linolenic acid to n-3 LCPUFA and expression of PPAR-alpha, acyl Coenzyme A oxidase 1 and carnitine acyl transferase I are incremented after feeding rats with α-linolenic acid-rich oils.

    Science.gov (United States)

    González-Mañán, Daniel; Tapia, Gladys; Gormaz, Juan Guillermo; D'Espessailles, Amanda; Espinosa, Alejandra; Masson, Lilia; Varela, Patricia; Valenzuela, Alfonso; Valenzuela, Rodrigo

    2012-07-01

    High dietary intake of n-6 fatty acids in relation to n-3 fatty acids may generate health disorders, such as cardiovascular and other chronic diseases. Fish consumption rich in n-3 fatty acids is low in Latin America, it being necessary to seek other alternatives to provide α-linolenic acid (ALA), precursor of n-3 LCPUFA (EPA and DHA). Two innovative oils were assayed, chia (Salvia hispanica) and rosa mosqueta (Rosa rubiginosa). This study evaluated hepatic bioconversion of ALA to EPA and DHA, expression of PPAR-α, acyl-Coenzyme A oxidase 1 (ACOX1) and carnitine acyltransferase I (CAT-I), and accumulation of EPA and DHA in plasma and adipose tissue in Sprague-Dawley rats. Three experimental groups were fed 21 days: sunflower oil (SFO, control); chia oil (CO); rosa mosqueta oil (RMO). Fatty acid composition of total lipids and phospholipids from plasma, hepatic and adipose tissue was assessed by gas-liquid chromatography and TLC. Expression of PPAR-α (RT-PCR) and ACOX1 and CAT-I (Western blot). CO and RMO increased plasma, hepatic and adipose tissue levels of ALA, EPA and DHA and decreased n-6:n-3 ratio compared to SFO (p oil.

  10. Signalling properties of lysophosphatidic acid.

    Science.gov (United States)

    Durieux, M E; Lynch, K R

    1993-06-01

    Lysophosphatidic acid (LPA) is the simplest natural phospholipid, primarily known as a membrane component and metabolic intermediate. However, a remarkable variety of biological effects of this compound have come to light, seemingly pointing to an additional role for LPA as a signalling molecule. In this review, Marcel Durieux and Kevin Lynch integrate the recent information that indicates that LPA could be an intercellular messenger, possibly acting through a G protein-coupled receptor, and with a role in cell growth and motility.

  11. Pro-lipogenic Action of Lysophosphatidic Acid in Ovarian Cancer

    Science.gov (United States)

    2014-04-01

    synthetic progestins used in oral contraceptives enhances fatty acid synthase-dependent breast cancer cell proliferation and survival. Int. J. Oncol. 26...acid in ovarian cancer PRINCIPAL INVESTIGATOR: Xianjun Fang CONTRACTING ORGANIZATION: Virginia Commonwealth University Richmond...2011-30 December 2013 4. TITLE AND SUBTITLE Pro-lipogenic action of lysophosphatidic acid in ovarian cancer 5a. CONTRACT NUMBER 5b. GRANT

  12. In vitro effect of lysophosphatidic acid on proliferation, invasion and ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of lysophosphatidic acid (LPA) on the proliferation, invasion and migration ability of 3AO, SKOV3 and CAOV3 human ovarian cancer cell lines. Methods: SKOV3, 3AO and CAOV3 cell lines were respectively treated with LPA. Changes in the proliferation rate of these cell lines were observed ...

  13. In vitro effect of lysophosphatidic acid on proliferation, invasion and ...

    African Journals Online (AJOL)

    Tsujino M, Fujii M, Okabe K, Mori T, Fukushima N,. Tsujiuchi T. Differential expressions and DNA methylation patterns of lysophosphatidic acid receptor genes in human colon cancer cells. Virchows Arch. 2010; 457: 669-676. 11. Pennington KP, Wickramanayake A, Norquist BM, Pennil. CC, Garcia RL, Agnew KJ, Taniguchi ...

  14. Plant Lysophosphatidic Acids: A Rich Source for Bioactive Lysophosphatidic Acids and Their Pharmacological Applications.

    Science.gov (United States)

    Lee, Byung-Hwan; Choi, Sun-Hye; Kim, Hyeon-Joong; Jung, Seok-Won; Kim, Ho-Kyoung; Nah, Seung-Yeol

    2016-01-01

    Lysophosphatidic acid (1-acyl-2-lyso-sn-glycero-3-phosphatidic acid; LPA) is a simple and minor phospholipid in plants. Plant LPAs are merely metabolic intermediates in de novo lipid synthesis in plant cell membranes or for glycerophospholipid storage. The production and metabolisms of LPAs in animals are also well characterized and LPAs have diverse cellular effects in animal systems; i.e., from brain development to wound healing through the activation of G protein-coupled LPA receptors. Recent studies show that various foodstuffs such as soybean, cabbage and seeds such as sesame and sunflower contain bioactive LPAs. Some LPAs are produced from phosphatidic acid during the digestion of foodstuff. In addition, herbal medicines such as corydalis tuber, and especially ginseng, contain large amounts of LPAs compared to foodstuffs. Herbal LPAs bind to cell surface LPA receptors in animal cells and exert their biological effects. Herbal LPAs elicit [Ca(2+)]i transient and are coupled to various Ca(2+)-dependent ion channels and receptor regulations via the activation of LPA receptors. They also showed beneficial effects of in vitro wound healing, in vivo anti-gastric ulcer, anti-Alzheimer's disease, autotaxin inhibition and anti-metastasis activity. Thus, herbal LPAs can be useful agents for human health. Humans can utilize exogenous plant-derived LPAs for preventive or therapeutic purposes if plant-derived LPAs are developed as functional foods or natural medicine targeting LPA receptors. This brief review article introduces the known rich sources of herbal LPAs and herbal LPA binding protein, describes their biological effects, and further addresses possible clinical applications.

  15. Steroid binding to Autotaxin links bile salts and lysophosphatidic acid signalling

    NARCIS (Netherlands)

    Keune, Willem-Jan; Hausmann, Jens; Bolier, Ruth; Tolenaars, Dagmar; Kremer, Andreas; Heidebrecht, Tatjana; Joosten, Robbie P.; Sunkara, Manjula; Morris, Andrew J.; Matas-Rico, Elisa; Moolenaar, Wouter H.; Oude Elferink, Ronald P.; Perrakis, Anastassis

    2016-01-01

    Autotaxin (ATX) generates the lipid mediator lysophosphatidic acid (LPA). ATX-LPA signalling is involved in multiple biological and pathophysiological processes, including vasculogenesis, fibrosis, cholestatic pruritus and tumour progression. ATX has a tripartite active site, combining a hydrophilic

  16. Lysophosphatidic acid triggers mast cell-driven atherosclerotic plaque destabilization by increasing vascular inflammation.

    NARCIS (Netherlands)

    Bot, M.; , van, Berkel T.J.C.

    2013-01-01

    Lysophosphatidic acid (LPA), a bioactive lysophospholipid, accumulates in the atherosclerotic plaque. It has the capacity to activate mast cells, which potentially exacerbates plaque progression. In this study, we thus aimed to investigate whether LPA contributes to plaque destabilization by

  17. Lysophosphatidic Acid (LPA Signaling in Human and Ruminant Reproductive Tract

    Directory of Open Access Journals (Sweden)

    Izabela Wocławek-Potocka

    2014-01-01

    Full Text Available Lysophosphatidic acid (LPA through activating its G protein-coupled receptors (LPAR 1–6 exerts diverse cellular effects that in turn influence several physiological processes including reproductive function of the female. Studies in various species of animals and also in humans have identified important roles for the receptor-mediated LPA signaling in multiple aspects of human and animal reproductive tract function. These aspects range from ovarian and uterine function, estrous cycle regulation, early embryo development, embryo implantation, decidualization to pregnancy maintenance and parturition. LPA signaling can also have pathological consequences, influencing aspects of endometriosis and reproductive tissue associated tumors. The review describes recent progress in LPA signaling research relevant to human and ruminant reproduction, pointing at the cow as a relevant model to study LPA influence on the human reproductive performance.

  18. Lysophosphatidic Acid (LPA) Signaling in Human and Ruminant Reproductive Tract

    Science.gov (United States)

    Wocławek-Potocka, Izabela; Rawińska, Paulina; Kowalczyk-Zieba, Ilona; Boruszewska, Dorota; Sinderewicz, Emilia; Waśniewski, Tomasz; Skarzynski, Dariusz Jan

    2014-01-01

    Lysophosphatidic acid (LPA) through activating its G protein-coupled receptors (LPAR 1–6) exerts diverse cellular effects that in turn influence several physiological processes including reproductive function of the female. Studies in various species of animals and also in humans have identified important roles for the receptor-mediated LPA signaling in multiple aspects of human and animal reproductive tract function. These aspects range from ovarian and uterine function, estrous cycle regulation, early embryo development, embryo implantation, decidualization to pregnancy maintenance and parturition. LPA signaling can also have pathological consequences, influencing aspects of endometriosis and reproductive tissue associated tumors. The review describes recent progress in LPA signaling research relevant to human and ruminant reproduction, pointing at the cow as a relevant model to study LPA influence on the human reproductive performance. PMID:24744506

  19. Functional lysophosphatidic acid receptors expressed in Oryzias latipes.

    Science.gov (United States)

    Morimoto, Yuji; Ishii, Shoichi; Ishibashi, Jun-Ichi; Katoh, Kazutaka; Tsujiuchi, Toshifumi; Kagawa, Nao; Fukushima, Nobuyuki

    2014-11-10

    Lysophosphatidic acid (LPA) signaling is known to play biological and pathophysiological roles in many types of animals. Medaka (Oryzias latipes) is an experimental fish that can be easily maintained, propagated, and analyzed, and whose genome has been completely sequenced. However, there is limited information available regarding medaka LPA receptors. Here, using information from the medaka genome database, we examine the genomic structures, expression, and functions of six LPA receptor genes, Lpar1-Lpar6. Our analyses reveal that the genomic structures of Lpar1 and Lpar4 are different from those deduced from the database. Functional analyses using a heterologous expression system demonstrate that all medaka LPA receptors except for LPA5b respond to LPA treatment with cytoskeletal changes. These findings provide useful information on the structure and function of medaka LPA receptor genes, and identify medaka as a useful experimental model for exploration of the biological significance of LPA signaling. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Autotaxin-Lysophosphatidic Acid: From Inflammation to Cancer Development

    Directory of Open Access Journals (Sweden)

    Silvia Anahi Valdés-Rives

    2017-01-01

    Full Text Available Lysophosphatidic acid (LPA is a ubiquitous lysophospholipid and one of the main membrane-derived lipid signaling molecules. LPA acts as an autocrine/paracrine messenger through at least six G protein-coupled receptors (GPCRs, known as LPA1–6, to induce various cellular processes including wound healing, differentiation, proliferation, migration, and survival. LPA receptors and autotaxin (ATX, a secreted phosphodiesterase that produces this phospholipid, are overexpressed in many cancers and impact several features of the disease, including cancer-related inflammation, development, and progression. Many ongoing studies aim to understand ATX-LPA axis signaling in cancer and its potential as a therapeutic target. In this review, we discuss the evidence linking LPA signaling to cancer-related inflammation and its impact on cancer progression.

  1. Lysophosphatidic acid metabolism and elimination in cardiovascular disease

    Science.gov (United States)

    Salous, Abdelghaffar Kamal

    The bioactive lipids lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are present in human and mouse plasma at a concentration of ~0.1-1 microM and regulate physiological and pathophysiological processes in the cardiovascular system including atherothrombosis, intimal hyperplasia, and immune function, edema formation, and permeability. PPAP2B, the gene encoding LPP3, a broad activity integral membrane enzyme that terminates LPA actions in the vasculature, has a single nucleotide polymorphism that been recently associated with coronary artery disease risk. The synthesis and signaling of LPA and S1P in the cardiovascular system have been extensively studied but the mechanisms responsible for their elimination are less well understood. The broad goal of this research was to examine the role of LPP3 in the termination of LPA signaling in models of cardiovascular disease involving vascular wall cells, investigate the role of LPP3 in the elimination of plasma LPA, and further characterize the elimination of plasma LPA. The central hypothesis is that LPP3 plays an important role in attenuating the pathological responses to LPA signaling and that it mediates the elimination of exogenously applied bioactive lipids from the plasma. These hypotheses were tested using molecular biological approaches, in vitro studies, synthetic lysophospholipid mimetics, modified surgical procedures, and mass spectrometry assays. My results indicated that LPP3 played a critical role in attenuating LPA signaling mediating the pathological processes of intimal hyperplasia and vascular leak in mouse models of disease. Additionally, enzymatic inactivation of lysophospholipids by LPP and PLA enzymes in the plasma was not a primary mechanism for the rapid elimination of plasma LPA and S1P. Instead, evidence strongly suggested a transcellular uptake mechanism by hepatic non-parenchymal cells as the predominant mechanism for elimination of these molecules. These results support a model in

  2. Lysophosphatidic acid targets vascular and oncogenic pathways via RAGE signaling

    Science.gov (United States)

    Touré, Fatouma; Chitayat, Seth; Pei, Renjun; Song, Fei; Li, Qing; Zhang, Jinghua; Rosario, Rosa; Ramasamy, Ravichandran; Chazin, Walter J.

    2012-01-01

    The endogenous phospholipid lysophosphatidic acid (LPA) regulates fundamental cellular processes such as proliferation, survival, motility, and invasion implicated in homeostatic and pathological conditions. Hence, delineation of the full range of molecular mechanisms by which LPA exerts its broad effects is essential. We report avid binding of LPA to the receptor for advanced glycation end products (RAGE), a member of the immunoglobulin superfamily, and mapping of the LPA binding site on this receptor. In vitro, RAGE was required for LPA-mediated signal transduction in vascular smooth muscle cells and C6 glioma cells, as well as proliferation and migration. In vivo, the administration of soluble RAGE or genetic deletion of RAGE mitigated LPA-stimulated vascular Akt signaling, autotaxin/LPA-driven phosphorylation of Akt and cyclin D1 in the mammary tissue of transgenic mice vulnerable to carcinogenesis, and ovarian tumor implantation and development. These findings identify novel roles for RAGE as a conduit for LPA signaling and suggest targeting LPA–RAGE interaction as a therapeutic strategy to modify the pathological actions of LPA. PMID:23209312

  3. Biosynthesis of Alkyl Lysophosphatidic Acid by Diacylglycerol Kinases

    Science.gov (United States)

    Gellett, Amanda M.; Kharel, Yugesh; Sunkara, Manjula; Morris, Andrew J.; Lynch, Kevin R.

    2012-01-01

    Lysophosphatidic acid (LPA) designates a family of bioactive phosphoglycerides that differ in the length and degree of saturation of their radyl chain. Additional diversity is provided by the linkage of the radyl chain to glycerol: acyl, alkyl, or alk-1-enyl. Acyl-LPAs are the predominate species in tissues and biological fluids. Alkyl-LPAs exhibit distinct pharmacodynamics at LPA receptors, potently drive platelet aggregation, and contribute to ovarian cancer aggressiveness. Multiple biosynthetic pathways exist for alkyl-LPA production. Herein we report that diacylglycerol kinases (DGKs) contribute to cell-associated alkyl-LPA production involving phosphorylation of 1-alkyl-2-acetyl glycerol and document the biosynthesis of alkyl-LPA by DGKs in SKOV-3 ovarian cancer cells, specifically identifying the contribution of DGKα. Concurrently, we discovered that treating SKOV-3 ovarian cancer cell with a sphingosine analog stimulates conversion of exogenous 1-alkyl-2-acetyl glycerol to alkyl-LPA, indicating that DGKα contributes significantly to the production of alkyl-LPA in SKOV-3 cells and identifying cross-talk between the sphingolipid and glycerol lipid pathways. PMID:22627129

  4. Lysophosphatidic acid mediates pleiotropic responses in skeletal muscle cells

    International Nuclear Information System (INIS)

    Jean-Baptiste, Gael; Yang Zhao; Khoury, Chamel; Greenwood, Michael T.

    2005-01-01

    Lysophosphatidic acid (LPA) is a potent modulator of growth, cell survival, and apoptosis. Although all four LPA receptors are expressed in skeletal muscle, very little is known regarding the role they play in this tissue. We used RT-PCR to demonstrate that cultured skeletal muscle C2C12 cells endogenously express multiple LPA receptor subtypes. The demonstration that LPA mediates the activation of ERK1/2 MAP kinase and Akt/PKB in C2C12 cells is consistent with the widely observed mitogenic properties of LPA. In spite of these observations, LPA did not induce proliferation in C2C12 cells. Paradoxically, we found that prolonged treatment of C2C12 cells with LPA led to caspase 3 and PARP cleavage as well as the activation of stress-associated MAP kinases JNK and p38. In spite of these typically pro-apoptotic responses, LPA did not induce cell death. Blocking ERK1/2 and Akt/PKB activation with specific pharmacological inhibitors, nevertheless, stimulated LPA-mediated apoptosis. Taken together, these results suggest that both mitogenic and apoptotic responses serve to counterbalance the effects of LPA in cultured C2C12 cells

  5. Lysophosphatidate induces chemo-resistance by releasing breast cancer cells from taxol-induced mitotic arrest.

    Directory of Open Access Journals (Sweden)

    Nasser Samadi

    Full Text Available Taxol is a microtubule stabilizing agent that arrests cells in mitosis leading to cell death. Taxol is widely used to treat breast cancer, but resistance occurs in 25-69% of patients and it is vital to understand how Taxol resistance develops to improve chemotherapy. The effects of chemotherapeutic agents are overcome by survival signals that cancer cells receive. We focused our studies on autotaxin, which is a secreted protein that increases tumor growth, aggressiveness, angiogenesis and metastasis. We discovered that autotaxin strongly antagonizes the Taxol-induced killing of breast cancer and melanoma cells by converting the abundant extra-cellular lipid, lysophosphatidylcholine, into lysophosphatidate. This lipid stimulates specific G-protein coupled receptors that activate survival signals.In this study we determined the basis of these antagonistic actions of lysophosphatidate towards Taxol-induced G2/M arrest and cell death using cultured breast cancer cells. Lysophosphatidate does not antagonize Taxol action in MCF-7 cells by increasing Taxol metabolism or its expulsion through multi-drug resistance transporters. Lysophosphatidate does not lower the percentage of cells accumulating in G2/M by decreasing exit from S-phase or selective stimulation of cell death in G2/M. Instead, LPA had an unexpected and remarkable action in enabling MCF-7 and MDA-MB-468 cells, which had been arrested in G2/M by Taxol, to normalize spindle structure and divide, thus avoiding cell death. This action involves displacement of Taxol from the tubulin polymer fraction, which based on inhibitor studies, depends on activation of LPA receptors and phosphatidylinositol 3-kinase.This work demonstrates a previously unknown consequence of lysophosphatidate action that explains why autotaxin and lysophosphatidate protect against Taxol-induced cell death and promote resistance to the action of this important therapeutic agent.

  6. Thermodynamics of Ligand Binding to Acyl-Coenzyme A Binding Protein Studied by Titration Calorimetry

    DEFF Research Database (Denmark)

    Færgeman, Nils Joakim; Sigurskjold, Bent Walther; Kragelund, Birthe B.

    1996-01-01

    Ligand binding to recombinant bovine acyl-CoA binding protein (ACBP) was examined using isothermal microcalorimetry. Microcalorimetric measurements confirm that the binding affinity of acyl-CoA esters for ACBP is strongly dependent on the length of the acyl chain with a clear preference for acyl-...

  7. Regulation of lipolytic activity by long-chain acyl-coenzyme A in islets and adipocytes

    DEFF Research Database (Denmark)

    Hu, Liping; Deeney, Jude T; Nolan, Christopher J

    2005-01-01

    -cells. The mechanisms by which lipolysis is regulated in different tissues is, therefore, of considerable interest. Here, the effects of long-chain acyl-CoA esters (LC-CoA) on lipase activity in islets and adipocytes were compared. Palmitoyl-CoA (Pal-CoA, 1-10 microM) stimulated lipase activity in islets from both....... The inhibitory effect of LC-CoA on adipocyte HSL was dependent on phosphorylation and enhanced by acyl-CoA-binding protein (ACBP). In contrast, the stimulatory effect on islet lipase activity was blocked by ACBP, presumably due to binding and sequestration of LC-CoA. These data suggest the following intertissue...

  8. STRUCTURAL AND FUNCTIONAL ASPECTS OF ACYL-COENZYME A BINDING PROTEINS (ACBPs: A COMPREHENSIVE REVIEW

    Directory of Open Access Journals (Sweden)

    Richa Arya

    2012-06-01

    Full Text Available ACBP was originally identified as a mammalian diazepam binding inhibitor – a neuropeptide that has the ability to inhibit diazepam binding to the �-aminobutyric acid (GABA receptor (Guidotti et al., 1983. Typically, ACBPs are small (~10 kDa cytosolic proteins (Burton et al., 2005. However, a number of hybrid ACBPs are reported that are fused with ankyrin repeats, such as ACBP1 and ACBP2 in Arabidopsis thaliana (Chye et al., 1999; Li and Chye, 2003. Other functional domains, such as the human peroxisomal �3/ �2-enoyl-CoA isomerase (Geisbrecht et al., 1999, or any non-functional/ uncharacterized domain are also cited. ACBP predominantly functions as an intracellular acyl-CoA transporter and pool former, and is critical to lipid metabolism in cells (Gossett et al., 1996; Knudsen et al., 2000; Schroeder et al., 1998. Impaired lipid metabolism and other cellular functions in humans arising out of ACBP defects thus need to be explored. ACBP has only been reported in eukaryotes, not in prokaryotes, except for a few pathogenic eubacteria that might have acquired ACBP from eukaryotic hosts via lateral gene transfer (Burton et al., 2005. Whole genome sequences of several prokaryotes and pathogens being available currently, it is worthwhile to extend search for ACBPs beyond eukaryotes as well, to explore their potential as drug targets, given their essential role in lipid metabolism. As a prelude to such investigations, the current review summarizes available knowledge of ACBPs and outlines the scope of future research.

  9. Thermodynamics of ligand binding to acyl-coenzyme A binding protein studied by titration calorimetry

    DEFF Research Database (Denmark)

    Færgeman, Nils J.; Sigurskjold, B W; Kragelund, B B

    1996-01-01

    Ligand binding to recombinant bovine acyl-CoA binding protein (ACBP) was examined using isothermal microcalorimetry. Microcalorimetric measurements confirm that the binding affinity of acyl-CoA esters for ACBP is strongly dependent on the length of the acyl chain with a clear preference for acyl-...

  10. Polyunsaturated fatty acyl-coenzyme As are inhibitors of cholesterol biosynthesis in zebrafish and mice

    Directory of Open Access Journals (Sweden)

    Santhosh Karanth

    2013-11-01

    Lipid disorders pose therapeutic challenges. Previously we discovered that mutation of the hepatocyte β-hydroxybutyrate transporter Slc16a6a in zebrafish causes hepatic steatosis during fasting, marked by increased hepatic triacylglycerol, but not cholesterol. This selective diversion of trapped ketogenic carbon atoms is surprising because acetate and acetoacetate can exit mitochondria and can be incorporated into both fatty acids and cholesterol in normal hepatocytes. To elucidate the mechanism of this selective diversion of carbon atoms to fatty acids, we fed wild-type and slc16a6a mutant animals high-protein ketogenic diets. We find that slc16a6a mutants have decreased activity of the rate-limiting enzyme of cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr, despite increased Hmgcr protein abundance and relative incorporation of mevalonate into cholesterol. These observations suggest the presence of an endogenous Hmgcr inhibitor. We took a candidate approach to identify such inhibitors. First, we found that mutant livers accumulate multiple polyunsaturated fatty acids (PUFAs and PUFA-CoAs, and we showed that human HMGCR is inhibited by PUFA-CoAs in vitro. Second, we injected mice with an ethyl ester of the PUFA eicosapentaenoic acid and observed an acute decrease in hepatic Hmgcr activity, without alteration in Hmgcr protein abundance. These results elucidate a mechanism for PUFA-mediated cholesterol lowering through direct inhibition of Hmgcr.

  11. Autotaxin, a lysophosphatidic acid-producing ectoenzyme, promotes lymphocyte entry into secondary lymphoid organs

    OpenAIRE

    Kanda, Hidenobu; Newton, Rebecca; Klein, Russell; Morita, Yuka; Gunn, Michael D.; Rosen, Steven D.

    2008-01-01

    The extracellular lysophospholipase D, autotaxin (ATX), and its product lysophosphatidic acid (LPA) have diverse roles in development and cancer, but little is known about functions in the immune system. We found that ATX was highly expressed in high endothelial venules (HEVs) of lymphoid organs and was secreted. Chemokine-activated lymphocytes expressed enhanced receptors for ATX, providing a mechanism to target the secreted ATX onto lymphocytes undergoing recruitment. LPA induced chemokines...

  12. Crystal Structure of Autotaxin, a Lysophospholipase D that Produces Lipid Mediator Lysophosphatidic Acids

    Science.gov (United States)

    Nishimasu, Hiroshi; Takagi, Junichi; Aoki, Junken; Nureki, Osamu

    Autotaxin (ATX), also known as Enpp2, is a secreted lysophospholipase D that hydrolyzes lysophosphatidylcholine to generate lysophosphatidic acid (LPA), a lipid mediator that activates G-protein coupled receptors to evoke various cellular responses. We solved the crystal structures of mouse ATX alone and in complex with LPAs with different acyl-chain lengths and saturations. The structures reveal a multidomain architecture that may maintain the structure of the hydrophobic pocket, in which the respective LPA molecules are accommodated in distinct conformations. Moreover, our data suggest that the produced LPAs are transferred from the catalytic pocket to cognate receptors through a hydrophobic channel.

  13. Deficiency or inhibition of lysophosphatidic acid receptor 1 protects against hyperoxia-induced lung injury in neonatal rats

    NARCIS (Netherlands)

    Chen, X.; Walther, F. J.; van Boxtel, R.|info:eu-repo/dai/nl/344456110; Laghmani, E. H.; Sengers, R. M. A.; Folkerts, G.; DeRuiter, M. C.; Cuppen, E.|info:eu-repo/dai/nl/183050487; Wagenaar, G. T. M.

    Aim Blocking of lysophosphatidic acid (LPA) receptor (LPAR) 1 may be a novel therapeutic option for bronchopulmonary dysplasia (BPD) by preventing the LPAR1-mediated adverse effects of its ligand (LPA), consisting of lung inflammation, pulmonary arterial hypertension (PAH) and fibrosis. Methods In

  14. Lysophosphatidic acid generation by pulmonary NKT cell ENPP-2/autotaxin exacerbates hyperoxic lung injury.

    Science.gov (United States)

    Nowak-Machen, Martina; Lange, Martin; Exley, Mark; Wu, Sherry; Usheva, Anny; Robson, Simon C

    2015-12-01

    Hyperoxia is still broadly used in clinical practice in order to assure organ oxygenation in critically ill patients, albeit known toxic effects. In this present study, we hypothesize that lysophosphatidic acid (LPA) mediates NKT cell activation in a mouse model of hyperoxic lung injury. In vitro, pulmonary NKT cells were exposed to hyperoxia for 72 h, and the induction of the ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP-2) was examined and production of lysophosphatidic acid (LPA) was measured. In vivo, animals were exposed to 100 % oxygen for 72 h and lungs and serum were harvested. Pulmonary NKT cells were then incubated with the LPA antagonist Brp-LPA. Animals received BrP-LPA prior to oxygen exposure. Autotaxin (ATX, ENPP-2) was significantly up-regulated on pulmonary NKT cells after hyperoxia (p NKT cells. LPA levels were significantly reduced by incubating NKT cells with LPA-BrP during oxygen exposure (p NKT cell numbers in vivo. BrP-LPA injection significantly improved survival as well as significantly decreased lung injury and lowered pulmonary NKT cell numbers. We conclude that NKT cell-induced hyperoxic lung injury is mediated by pro-inflammatory LPA generation, at least in part, secondary to ENPP-2 up-regulation on pulmonary NKT cells. Being a potent LPA antagonist, BrP-LPA prevents hyperoxia-induced lung injury in vitro and in vivo.

  15. Lysophosphatidic acid-3 receptor-mediated feed-forward production of lysophosphatidic acid: an initiator of nerve injury-induced neuropathic pain

    Directory of Open Access Journals (Sweden)

    Aoki Junken

    2009-11-01

    Full Text Available Abstract Background We previously reported that intrathecal injection of lysophosphatidylcholine (LPC induced neuropathic pain through activation of the lysophosphatidic acid (LPA-1 receptor, possibly via conversion to LPA by autotaxin (ATX. Results We examined in vivo LPA-induced LPA production using a biological titration assay with B103 cells expressing LPA1 receptors. Intrathecal administration of LPC caused time-related production of LPA in the spinal dorsal horn and dorsal roots, but not in the dorsal root ganglion, spinal nerve or sciatic nerve. LPC-induced LPA production was markedly diminished in ATX heterozygotes, and was abolished in mice that were deficient in LPA3, but not LPA1 or LPA2 receptors. Similar time-related and LPA3 receptor-mediated production of LPA was observed following intrathecal administration of LPA. In an in vitro study using spinal cord slices, LPA-induced LPA production was also mediated by ATX and the LPA3 receptor. Intrathecal administration of LPA, in contrast, induced neuropathic pain, which was abolished in mice deficient in LPA1 or LPA3 receptors. Conclusion These findings suggest that feed-forward LPA production is involved in LPA-induced neuropathic pain.

  16. Cell Shrinkage is Essential in Lysophosphatidic Acid Signaling in Ehrlich Ascites

    DEFF Research Database (Denmark)

    Pedersen, Susanne; Hoffmann, Else Kay; Hougaard, Charlotte

    2000-01-01

    The present study aimed at elucidating the initial intracellular lysophosphatidic acid (LPA)-induced signaling events, in order to investigate the sequence in which LPA affects the intracellular concentration of free, cytosolic Ca(2+), [Ca(2+)](i), ion channels, the F-actin cytoskeleton, cell...... volume and the Na(+)/H(+) exchanger. We found that stimulation of Ehrlich cells with LPA induced a transient, concentration-dependent increase in [Ca(2+)](i), which is due to Ca(2+) release from intracellular Ins(1,4,5)P(3)-sensitive stores as well as an influx of Ca(2+). The EC(50) values for LPA......; (ii) a subsequent cell shrinkage and increased polymerization of F-actin, and (iii) activation of a Na(+)/H(+) exchange, resulting in a concentration-dependent intracellular alkalinization. The EC(50) value for the LPA-induced rate of alkalinization was estimated at 0. 37 nm LPA. When cell shrinkage...

  17. Phosphorylation and Internalization of Lysophosphatidic Acid Receptors LPA1, LPA2, and LPA3.

    Directory of Open Access Journals (Sweden)

    Rocío Alcántara-Hernández

    Full Text Available The lysophosphatidic acid receptors LPA1, LPA2, and LPA3 were individually expressed in C9 cells and their signaling and regulation were studied. Agonist-activation increases intracellular calcium concentration in a concentration-dependent fashion. Phorbol myristate acetate markedly inhibited LPA1- and LPA3-mediated effect, whereas that mediated by LPA2 was only partially diminished; the actions of the phorbol ester were inhibited by bisindolylmaleimide I and by overnight incubation with the protein kinase C activator, which leads to down regulation of this protein kinase. Homologous desensitization was also observed for the three LPA receptors studied, with that of LPA2 receptors being consistently of lesser magnitude; neither inhibition nor down-regulation of protein kinase C exerted any effect on homologous desensitization. Activation of LPA1-3 receptors induced ERK 1/2 phosphorylation; this effect was markedly attenuated by inhibition of epidermal growth factor receptor tyrosine kinase activity, suggesting growth factor receptor transactivation in this effect. Lysophosphatidic acid and phorbol myristate acetate were able to induce LPA1-3 phosphorylation, in time- and concentration-dependent fashions. It was also clearly observed that agonists and protein kinase C activation induced internalization of these receptors. Phosphorylation of the LPA2 subtype required larger concentrations of these agents and its internalization was less intense than that of the other subtypes.Our data show that these three LPA receptors are phosphoproteins whose phosphorylation state is modulated by agonist-stimulation and protein kinase C-activation and that differences in regulation and cellular localization exist, among the subtypes.

  18. Lysophosphatidic Acid signals through specific lysophosphatidic Acid receptor subtypes to control key regenerative responses of human gingival and periodontal ligament fibroblasts.

    Science.gov (United States)

    George, Joju; Headen, Karmel V; Ogunleye, Afolabi O; Perry, Greg A; Wilwerding, Terrence M; Parrish, Lawrence C; McVaney, Timothy P; Mattson, John S; Cerutis, D Roselyn

    2009-08-01

    We showed that the pluripotent platelet growth factor and mediator lysophosphatidic acid (LPA) controls key regenerative responses of human gingival fibroblasts (GFs) and periodontal ligament fibroblasts (PDLFs) and positively modulates their responses to platelet-derived growth factor (PDGF). This study determined which LPA receptor (LPAR) subtype(s) LPA signals through to stimulate mitogenic extracellular signal-regulated kinase (ERK) 1/2 signaling and chemotaxis and to elicit intracellular Ca(2+) increases in GFs and PDLFs because many healing responses are calcium-dependent. Activation of mitogen-activated protein kinase was determined using Western blotting with an antibody to phosphorylated ERK1/2. Migration responses were measured using a microchemotaxis chamber. GF and PDLF intracellular Ca(2+) mobilization responses to multiple LPA species and LPAR subtype-specific agonists were measured by using a cell-permeable fluorescent Ca(2+) indicator dye. LPA stimulated ERK1/2 phosphorylation via LPA(1)(-3). For GFs, LPA(1) preferentially elicited chemotaxis, and LPA(1-3) for PDLFs, as confirmed using subtype-specific agonists. Elevation of intracellular calcium seems to be mediated through LPA(1) and LPA(3), with little, if any, contribution from LPA(2). To the best of our knowledge, this study provides the first evidence that LPA signals through specific LPAR subtypes to stimulate human oral fibroblast regenerative responses. These data, in conjunction with our previous findings showing that LPA modulates GF and PDLF responses to PDGF, suggest that LPA is a factor of emerging importance to oral wound healing.

  19. A novel highly potent autotaxin/ENPP2 inhibitor produces prolonged decreases in plasma lysophosphatidic acid formation in vivo and regulates urethral tension.

    Directory of Open Access Journals (Sweden)

    Hiroshi Saga

    Full Text Available Autotaxin, also known as ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2, is a secreted enzyme that has lysophospholipase D activity, which converts lysophosphatidylcholine to bioactive lysophosphatidic acid. Lysophosphatidic acid activates at least six G-protein coupled recpetors, which promote cell proliferation, survival, migration and muscle contraction. These physiological effects become dysfunctional in the pathology of cancer, fibrosis, and pain. To date, several autotaxin/ENPP2 inhibitors have been reported; however, none were able to completely and continuously inhibit autotaxin/ENPP2 in vivo. In this study, we report the discovery of a highly potent autotaxin/ENPP2 inhibitor, ONO-8430506, which decreased plasma lysophosphatidic acid formation. The IC50 values of ONO-8540506 for lysophospholipase D activity were 6.4-19 nM for recombinant autotaxin/ENPP2 proteins and 4.7-11.6 nM for plasma from various animal species. Plasma lysophosphatidic acid formation during 1-h incubation was almost completely inhibited by the addition of >300 nM of the compound to human plasma. In addition, when administered orally to rats at a dose of 30 mg/kg, the compound demonstrated good pharmacokinetics in rats and persistently inhibited plasma lysophosphatidic acid formation even at 24 h after administration. Smooth muscle contraction is a known to be promoted by lysophosphatidic acid. In this study, we showed that dosing rats with ONO-8430506 decreased intraurethral pressure accompanied by urethral relaxation. These findings demonstrate the potential of this autotaxin/ENPP2 inhibitor for the treatment of various diseases caused by lysophosphatidic acid, including urethral obstructive disease such as benign prostatic hyperplasia.

  20. Cloning, Characterization, and Expression Analysis of a Gene Encoding a Putative Lysophosphatidic Acid Acyltransferase from Seeds of Paeonia rockii.

    Science.gov (United States)

    Zhang, Qing-Yu; Niu, Li-Xin; Yu, Rui; Zhang, Xiao-Xiao; Bai, Zhang-Zhen; Duan, Ke; Gao, Qing-Hua; Zhang, Yan-Long

    2017-06-01

    Tree peony (Paeonia section Moutan DC.) is an excellent woody oil crop, and the cloning and functional analysis of genes related to fatty acid (FA) metabolism from this organism has not been reported. Lysophosphatidic acid acyltransferase (LPAAT), which converts lysophosphatidic acid (LPA) to phosphatidic acid (PA), catalyzes the addition of fatty acyl moieties to the sn-2 position of the LPA glycerol backbone in triacylglycerol (TAG) biosynthesis. This project reports a putative lysophosphatidic acid acyltransferase gene PrLPAAT1 isolated from Paeonia rockii. Our data indicated that PrLPAAT1 has 1047 nucleotides and encodes a putative 38.8 kDa protein with 348 amino acid residues. Bioinformatic analysis demonstrated that PrLPAAT1 contains two transmembrane domains (TMDs). Subcellular localization analysis confirmed that PrLPAAT1 is a plasma membrane protein. Phylogenetic analysis revealed that PrLPAAT1 shared 74.3 and 65.5% amino acid sequence identities with the LPAAT1 sequences from columbine and grape, respectively. PrLPAAT1 belongs to AGPAT family, and may have acyltransferase activity. PrLPAAT1 was ubiquitously expressed in diverse tissues, and PrLPAAT1 expression was higher in the flower and developing seed. PrLPAAT1 is probably an important component in the FA accumulation process, especially during the early stages of seed development. PrLPAAT1 overexpression using a seed-specific promoter increased total FA content and the main FA accumulation in Arabidopsis transgenic plants.

  1. The Autotaxin–Lysophosphatidic Acid Axis Modulates Histone Acetylation and Gene Expression during Oligodendrocyte Differentiation

    Science.gov (United States)

    Wheeler, Natalie A.; Lister, James A.

    2015-01-01

    During development, oligodendrocytes (OLGs), the myelinating cells of the CNS, undergo a stepwise progression during which OLG progenitors, specified from neural stem/progenitor cells, differentiate into fully mature myelinating OLGs. This progression along the OLG lineage is characterized by well synchronized changes in morphology and gene expression patterns. The latter have been found to be particularly critical during the early stages of the lineage, and they have been well described to be regulated by epigenetic mechanisms, especially by the activity of the histone deacetylases HDAC1 and HDAC2. The data presented here identify the extracellular factor autotaxin (ATX) as a novel upstream signal modulating HDAC1/2 activity and gene expression in cells of the OLG lineage. Using the zebrafish as an in vivo model system as well as rodent primary OLG cultures, this functional property of ATX was found to be mediated by its lysophospholipase D (lysoPLD) activity, which has been well characterized to generate the lipid signaling molecule lysophosphatidic acid (LPA). More specifically, the lysoPLD activity of ATX was found to modulate HDAC1/2 regulated gene expression during a time window coinciding with the transition from OLG progenitor to early differentiating OLG. In contrast, HDAC1/2 regulated gene expression during the transition from neural stem/progenitor to OLG progenitor appeared unaffected by ATX and its lysoPLD activity. Thus, together, our data suggest that an ATX–LPA–HDAC1/2 axis regulates OLG differentiation specifically during the transition from OLG progenitor to early differentiating OLG and via a molecular mechanism that is evolutionarily conserved from at least zebrafish to rodent. SIGNIFICANCE STATEMENT The formation of the axon insulating and supporting myelin sheath by differentiating oligodendrocytes (OLGs) in the CNS is considered an essential step during vertebrate development. In addition, loss and/or dysfunction of the myelin sheath has

  2. Toluene diisocyanate: Induction of the autotaxin-lysophosphatidic acid axis and its association with airways symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Broström, Julia M. [Division of Occupational and Environmental Medicine, Lund University, SE 221 85 Lund (Sweden); Ye, Zhi-wei [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77 Stockholm (Sweden); Axmon, Anna; Littorin, Margareta; Tinnerberg, Håkan; Lindh, Christian H. [Division of Occupational and Environmental Medicine, Lund University, SE 221 85 Lund (Sweden); Zheng, Huiyuan; Ghalali, Aram; Stenius, Ulla [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77 Stockholm (Sweden); Jönsson, Bo A.G. [Division of Occupational and Environmental Medicine, Lund University, SE 221 85 Lund (Sweden); Högberg, Johan, E-mail: johan.hogberg@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77 Stockholm (Sweden)

    2015-09-15

    Diisocyanates are industrial chemicals which have a wide range of applications in developed and developing countries. They are notorious lung toxicants and respiratory sensitizers. However, the mechanisms behind their adverse effects are not adequately characterized. Autotaxin (ATX) is an enzyme producing lysophosphatidic acid (LPA), and the ATX-LPA axis has been implicated in lung related inflammatory conditions and diseases, including allergic asthma, but not to toxicity of environmental low-molecular-weight chemicals. We investigated effects of toluene diisocyanate (TDI) on ATX induction in human lung epithelial cell models, and we correlated LPA-levels in plasma to biomarkers of TDI exposure in urine collected from workers exposed to < 5 ppb (parts per billion). Information on workers' symptoms was collected through interviews. One nanomolar TDI robustly induced ATX release within 10 min in vitro. A P2X7- and P2X4-dependent microvesicle formation was implicated in a rapid ATX release and a subsequent protein synthesis. Co-localization between purinergic receptors and ATX was documented by immunofluorescence and confocal microscopy. The release was modulated by monocyte chemoattractant protein-1 (MCP-1) and by extracellular ATP. In workers, we found a dose–response relationship between TDI exposure biomarkers in urine and LPA levels in plasma. Among symptomatic workers reporting “sneezing”, the LPA levels were higher than among non-symptomatic workers. This is the first report indicating induction of the ATX-LPA axis by an environmental low-molecular-weight chemical, and our data suggest a role for the ATX-LPA axis in TDI toxicity. - Highlights: • Human epithelial cells release autotaxin in response to 1 nM toluene diisocyanate (TDI). • The release involves P2X4 and P2X7 receptors and is modulated by ATP and MCP-1. • Lysophosphatidic acid (LPA) was measured in workers exposed to < 5 ppb TDI. • LPA in plasma correlated to TDI exposure

  3. Conserved residues and their role in the structure, function, and stability of acyl-coenzyme A binding protein

    DEFF Research Database (Denmark)

    Kragelund, B B; Poulsen, K; Andersen, K V

    1999-01-01

    for stability of the structure have likewise been identified and are Phe5, Ala9, Val12, Leu15, Leu25, Tyr28, Lys32, Gln33, Tyr73, Val77, and Leu80. Essentially, all of the conserved residues that maintain the stability are hydrophobic residues at the interface of the helices. Only one conserved polar residue...

  4. Transient structure formation in unfolded acyl-coenzyme A-binding protein observed by site-directed spin labelling

    DEFF Research Database (Denmark)

    Teilum, Kaare; Kragelund, Birthe B; Poulsen, Flemming M

    2002-01-01

    cysteine residue introduced into five different positions in the amino acid sequence. It was shown that the formation of structure in the folding peptide chain at conditions where 95% of the sample is unfolded brings the relaxation probe close to a wide range of residues in the peptide chain, which...... are not affected in the native folded structure. It is suggested that the experiment is recording the formation of many discrete and transient structures in the polypeptide chain in the preface of protein folding. Analysis of secondary chemical shifts shows a high propensity for alpha-helix formation in the C...

  5. Determination of an ensemble of structures representing the denatured state of the bovine acyl-coenzyme a binding protein

    DEFF Research Database (Denmark)

    Lindorff-Larsen, Kresten; Kristjansdottir, Sigridur; Teilum, Kaare

    2004-01-01

    The denatured state of a protein contains important information about the determinants of the folding process. By combining site-directed spin-labeling NMR experiments and restrained computer simulations, we have determined ensembles of conformations that represent the denatured state of the bovi...

  6. Metabolism of propionic acid to a novel acyl-coenzyme A thioester by mammalian cell lines and platelets.

    Science.gov (United States)

    Snyder, Nathaniel W; Basu, Sankha S; Worth, Andrew J; Mesaros, Clementina; Blair, Ian A

    2015-01-01

    Metabolism of propionate involves the activated acyl-thioester propionyl-CoA intermediate. We employed LC-MS/MS, LC-selected reaction monitoring/MS, and LC-high-resolution MS to investigate metabolism of propionate to acyl-CoA intermediates. We discovered that propionyl-CoA can serve as a precursor to the direct formation of a new six-carbon mono-unsaturated acyl-CoA. Time course and dose-response studies in human hepatocellular carcinoma HepG2 cells demonstrated that the six-carbon mono-unsaturated acyl-CoA was propionate-dependent and underwent further metabolism over time. Studies utilizing [(13)C1]propionate and [(13)C3]propionate suggested a mechanism of fatty acid synthesis, which maintained all six-carbon atoms from two propionate molecules. Metabolism of 2,2-[(2)H2]propionate to the new six-carbon mono-unsaturated acyl-CoA resulted in the complete loss of two deuterium atoms, indicating modification at C2 of the propionyl moiety. Coelution experiments and isotopic tracer studies confirmed that the new acyl-CoA was trans-2-methyl-2-pentenoyl-CoA. Acyl-CoA profiles following treatment of HepG2 cells with mono-unsaturated six-carbon fatty acids also supported this conclusion. Similar results were obtained with human platelets, mouse hepatocellular carcinoma Hepa1c1c7 cells, human bronchoalveolar carcinoma H358 cells, and human colon adenocarcinoma LoVo cells. Interestingly, trans-2-methyl-2-pentenoyl-CoA corresponds to a previously described acylcarnitine tentatively described in patients with propionic and methylmalonic acidemia. We have proposed a mechanism for this metabolic route consistent with all of the above findings. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  7. Metabolism of propionic acid to a novel acyl-coenzyme A thioester by mammalian cell lines and platelets[S

    Science.gov (United States)

    Snyder, Nathaniel W.; Basu, Sankha S.; Worth, Andrew J.; Mesaros, Clementina; Blair, Ian A.

    2015-01-01

    Metabolism of propionate involves the activated acyl-thioester propionyl-CoA intermediate. We employed LC-MS/MS, LC-selected reaction monitoring/MS, and LC-high-resolution MS to investigate metabolism of propionate to acyl-CoA intermediates. We discovered that propionyl-CoA can serve as a precursor to the direct formation of a new six-carbon mono-unsaturated acyl-CoA. Time course and dose-response studies in human hepatocellular carcinoma HepG2 cells demonstrated that the six-carbon mono-unsaturated acyl-CoA was propionate-dependent and underwent further metabolism over time. Studies utilizing [13C1]propionate and [13C3]propionate suggested a mechanism of fatty acid synthesis, which maintained all six-carbon atoms from two propionate molecules. Metabolism of 2,2-[2H2]propionate to the new six-carbon mono-unsaturated acyl-CoA resulted in the complete loss of two deuterium atoms, indicating modification at C2 of the propionyl moiety. Coelution experiments and isotopic tracer studies confirmed that the new acyl-CoA was trans-2-methyl-2-pentenoyl-CoA. Acyl-CoA profiles following treatment of HepG2 cells with mono-unsaturated six-carbon fatty acids also supported this conclusion. Similar results were obtained with human platelets, mouse hepatocellular carcinoma Hepa1c1c7 cells, human bronchoalveolar carcinoma H358 cells, and human colon adenocarcinoma LoVo cells. Interestingly, trans-2-methyl-2-pentenoyl-CoA corresponds to a previously described acylcarnitine tentatively described in patients with propionic and methylmalonic acidemia. We have proposed a mechanism for this metabolic route consistent with all of the above findings. PMID:25424005

  8. Ethylmalonic aciduria is associated with an amino acid variant of short chain acyl-coenzyme A dehydrogenase

    DEFF Research Database (Denmark)

    Corydon, M J; Gregersen, N; Lehnert, W

    1996-01-01

    metabolized by propionyl-CoA carboxylase to EMA. We have recently detected a guanine to adenine polymorphism in the SCAD gene at position 625 in the SCAD cDNA, which changes glycine 209 to serine (G209S). The variant allele (A625) is present in homozygous and in heterozygous form in 7 and 34.8% of the general...... found a significant overrepresentation of the variant allele. Eighty-one patients (60%) were homozygous for the A625 allele, 40 (30%) were heterozygous, and only 14 (10%) harbored the wild-type allele (G625) in homozygous form. By overexpressing the wild-type and variant protein (G209S) in Escherichia...

  9. Sunflower (Helianthus annuus) long-chain acyl-coenzyme A synthetases expressed at high levels in developing seeds.

    Science.gov (United States)

    Aznar-Moreno, Jose A; Venegas Calerón, Mónica; Martínez-Force, Enrique; Garcés, Rafael; Mullen, Robert; Gidda, Satinder K; Salas, Joaquín J

    2014-03-01

    Long chain fatty acid synthetases (LACSs) activate the fatty acid chains produced by plastidial de novo biosynthesis to generate acyl-CoA derivatives, important intermediates in lipid metabolism. Oilseeds, like sunflower, accumulate high levels of triacylglycerols (TAGs) in their seeds to nourish the embryo during germination. This requires that sunflower seed endosperm supports very active glycerolipid synthesis during development. Sunflower seed plastids produce large amounts of fatty acids, which must be activated through the action of LACSs, in order to be incorporated into TAGs. We cloned two different LACS genes from developing sunflower endosperm, HaLACS1 and HaLACS2, which displayed sequence homology with Arabidopsis LACS9 and LACS8 genes, respectively. These genes were expressed at high levels in developing seeds and exhibited distinct subcellular distributions. We generated constructs in which these proteins were fused to green fluorescent protein and performed transient expression experiments in tobacco cells. The HaLACS1 protein associated with the external envelope of tobacco chloroplasts, whereas HaLACS2 was strongly bound to the endoplasmic reticulum. Finally, both proteins were overexpressed in Escherichia coli and recovered as active enzymes in the bacterial membranes. Both enzymes displayed similar substrate specificities, with a very high preference for oleic acid and weaker activity toward stearic acid. On the basis of our findings, we discuss the role of these enzymes in sunflower oil synthesis. © 2013 Scandinavian Plant Physiology Society.

  10. Increased urinary lysophosphatidic acid in mouse with subtotal nephrectomy: potential involvement in chronic kidney disease.

    Science.gov (United States)

    Mirzoyan, Koryun; Baïotto, Anna; Dupuy, Aude; Marsal, Dimitri; Denis, Colette; Vinel, Claire; Sicard, Pierre; Bertrand-Michel, Justine; Bascands, Jean-Loup; Schanstra, Joost P; Klein, Julie; Saulnier-Blache, Jean-Sébastien

    2016-12-01

    Increased incidence of chronic kidney disease (CKD) with consecutive progression to end-stage renal disease represents a significant burden to healthcare systems. Renal tubulointerstitial fibrosis (TIF) is a classical hallmark of CKD and is well correlated with the loss of renal function. The bioactive lysophospholipid lysophosphatidic acid (LPA), acting through specific G-protein-coupled receptors, was previously shown to be involved in TIF development in a mouse model of unilateral ureteral obstruction. Here, we study the role of LPA in a mouse subjected to subtotal nephrectomy (SNx), a more chronic and progressive model of CKD. Five months after surgical nephron reduction, SNx mice showed massive albuminuria, extensive TIF, and glomerular hypertrophy when compared to sham-operated animals. Urinary and plasma levels of LPA were analyzed using liquid chromatography tandem mass spectrometry. LPA was significantly increased in SNx urine, not in plasma, and was significantly correlated with albuminuria and TIF. Moreover, SNx mice showed significant downregulation in the renal expression of lipid phosphate phosphohydrolases (LPP1, 2, and 3) that might be involved in reduced LPA bioavailability through dephosphorylation. We concluded that SNx increases urinary LPA through a mechanism that could involve co-excretion of plasma LPA with albumin associated with a reduction of its catabolism in the kidney. Because of the previously demonstrated profibrotic activity of LPA, the association of urinary LPA with TIF suggests the potential involvement of LPA in the development of advanced CKD in the SNx mouse model. Targeting LPA metabolism might represent an interesting approach in CKD treatment.

  11. 1-Oleoyl lysophosphatidic acid: a new mediator of emotional behavior in rats.

    Directory of Open Access Journals (Sweden)

    Estela Castilla-Ortega

    Full Text Available The role of lysophosphatidic acid (LPA in the control of emotional behavior remains to be determined. We analyzed the effects of the central administration of 1-oleoyl-LPA (LPA 18∶1 in rats tested for food consumption and anxiety-like and depression-like behaviors. For this purpose, the elevated plus-maze, open field, Y maze, forced swimming and food intake tests were performed. In addition, c-Fos expression in the dorsal periaqueductal gray matter (DPAG was also determined. The results revealed that the administration of LPA 18∶1 reduced the time in the open arms of the elevated plus-maze and induced hypolocomotion in the open field, suggesting an anxiogenic-like phenotype. Interestingly, these effects were present following LPA 18∶1 infusion under conditions of novelty but not under habituation conditions. In the forced swimming test, the administration of LPA 18∶1 dose-dependently increased depression-like behavior, as evaluated according to immobility time. LPA treatment induced no effects on feeding. However, the immunohistochemical analysis revealed that LPA 18∶1 increased c-Fos expression in the DPAG. The abundant expression of the LPA1 receptor, one of the main targets for LPA 18∶1, was detected in this brain area, which participates in the control of emotional behavior, using immunocytochemistry. These findings indicate that LPA is a relevant transmitter potentially involved in normal and pathological emotional responses, including anxiety and depression.

  12. Regulation of autotaxin expression and secretion by lysophosphatidate and sphingosine 1-phosphate[S

    Science.gov (United States)

    Benesch, Matthew G. K.; Zhao, Yuan Y.; Curtis, Jonathan M.; McMullen, Todd P. W.; Brindley, David N.

    2015-01-01

    Autotaxin (ATX) is a secreted enzyme, which produces extracellular lysophosphatidate (LPA) from lysophosphatidylcholine (LPC). LPA activates six G protein-coupled receptors and this is essential for vasculogenesis during embryonic development. ATX is also involved in wound healing and inflammation, and in tumor growth, metastasis, and chemo-resistance. It is, therefore, important to understand how ATX is regulated. It was proposed that ATX activity is inhibited by its product LPA, or a related lipid called sphingosine 1-phosphate (S1P). We now show that this apparent inhibition is ineffective at the high concentrations of LPC that occur in vivo. Instead, feedback regulation by LPA and S1P is mediated by inhibition of ATX expression resulting from phosphatidylinositol-3-kinase activation. Inhibiting ATX activity in mice with ONO-8430506 severely decreased plasma LPA concentrations and increased ATX mRNA in adipose tissue, which is a major site of ATX production. Consequently, the amount of inhibitor-bound ATX protein in the plasma increased. We, therefore, demonstrate the concept that accumulation of LPA in the circulation decreases ATX production. However, this feedback regulation can be overcome by the inflammatory cytokines, TNF-α or interleukin 1β. This enables high LPA and ATX levels to coexist in inflammatory conditions. The results are discussed in terms of ATX regulation in wound healing and cancer. PMID:25896349

  13. Autotaxin-Lysophosphatidic Acid Pathway in Intraocular Pressure Regulation and Glaucoma Subtypes.

    Science.gov (United States)

    Honjo, Megumi; Igarashi, Nozomi; Kurano, Makoto; Yatomi, Yutaka; Igarashi, Koji; Kano, Kuniyuki; Aoki, Junken; Weinreb, Robert N; Aihara, Makoto

    2018-02-01

    To compare the levels of autotaxin (ATX), lysophosphatidic acid (LPA), and lysophosphatidylcholine (LPC) in the aqueous humor (AH) of healthy control subjects with those of patients with different subtypes of glaucoma, and also to investigate the relationship of the ATX-LPA pathway with IOP and subtype of glaucoma. This study included 164 eyes of 164 consecutive cases of cataract and glaucoma surgery (37 healthy, 31 normal tension glaucoma, 49 primary open angle glaucoma, 28 secondary open angle glaucoma, and 19 exfoliation glaucoma). Aqueous levels of LPA, LPC, and ATX were quantified using liquid chromatography-tandem mass spectrometry and a two-site immunoenzymetric assay. The association between aqueous levels of ATX/LPA/LPC and IOP elevation in different glaucoma subtypes was investigated. The diagnostic values of indices of the ATX-LPA pathway were compared using receiver operating characteristic curve analysis. Notable increases in ATX/LPA/LPC levels in glaucoma patients were observed. The ATX-LPA pathway was significantly related to IOP elevation and the subtype of glaucoma, especially in SOAG and XFG patients, and the area under the curve was significant for discriminating glaucoma eyes from healthy eyes. Bioactive ATX/LPA/LPC concentrations were present in aqueous humor, and higher ATX and LPA concentrations were significantly correlated with IOP in all study subjects. Furthermore, the ATX-LPA pathway was significantly related to glaucoma subtype. These results reveal the potentially important role of the ATX-LPA pathway for IOP regulation in healthy subjects and glaucoma patients.

  14. A metabolically-stabilized phosphonate analog of lysophosphatidic acid attenuates collagen-induced arthritis.

    Directory of Open Access Journals (Sweden)

    Ioanna Nikitopoulou

    Full Text Available Rheumatoid arthritis (RA is a destructive arthropathy with systemic manifestations, characterized by chronic synovial inflammation. Under the influence of the pro-inflammatory milieu synovial fibroblasts (SFs, the main effector cells in disease pathogenesis become activated and hyperplastic while releasing a number of signals that include pro-inflammatory factors and tissue remodeling enzymes. Activated RA SFs in mouse or human arthritic joints express significant quantities of autotaxin (ATX, a lysophospholipase D responsible for the majority of lysophosphatidic acid (LPA production in the serum and inflamed sites. Conditional genetic ablation of ATX from SFs resulted in attenuation of disease symptoms in animal models, an effect attributed to diminished LPA signaling in the synovium, shown to activate SF effector functions. Here we show that administration of 1-bromo-3(S-hydroxy-4-(palmitoyloxybutyl-phosphonate (BrP-LPA, a metabolically stabilized analog of LPA and a dual function inhibitor of ATX and pan-antagonist of LPA receptors, attenuates collagen induced arthritis (CIA development, thus validating the ATX/LPA axis as a novel therapeutic target in RA.

  15. A Metabolically-Stabilized Phosphonate Analog of Lysophosphatidic Acid Attenuates Collagen-Induced Arthritis

    Science.gov (United States)

    Sevastou, Ioanna; Sirioti, Ivi; Samiotaki, Martina; Madan, Damian; Prestwich, Glenn D.; Aidinis, Vassilis

    2013-01-01

    Rheumatoid arthritis (RA) is a destructive arthropathy with systemic manifestations, characterized by chronic synovial inflammation. Under the influence of the pro-inflammatory milieu synovial fibroblasts (SFs), the main effector cells in disease pathogenesis become activated and hyperplastic while releasing a number of signals that include pro-inflammatory factors and tissue remodeling enzymes. Activated RA SFs in mouse or human arthritic joints express significant quantities of autotaxin (ATX), a lysophospholipase D responsible for the majority of lysophosphatidic acid (LPA) production in the serum and inflamed sites. Conditional genetic ablation of ATX from SFs resulted in attenuation of disease symptoms in animal models, an effect attributed to diminished LPA signaling in the synovium, shown to activate SF effector functions. Here we show that administration of 1-bromo-3(S)-hydroxy-4-(palmitoyloxy)butyl-phosphonate (BrP-LPA), a metabolically stabilized analog of LPA and a dual function inhibitor of ATX and pan-antagonist of LPA receptors, attenuates collagen induced arthritis (CIA) development, thus validating the ATX/LPA axis as a novel therapeutic target in RA. PMID:23923032

  16. LIPID PHOSPHATE PHOSPHOHYDROLASE TYPE 1 (LPP1) DEGRADES EXTRACELLULAR LYSOPHOSPHATIDIC ACID IN VIVO

    Science.gov (United States)

    Tomsig, Jose L.; Snyder, Ashley H.; Berdyshev, Evgeny V.; Skobeleva, Anastasia; Mataya, Chifundo; Natarajan, Viswanathan; Brindley, David N.; Lynch, Kevin R.

    2009-01-01

    Lysophosphatidic acid (LPA) is a lipid mediator that stimulates cell proliferation and growth and is involved in physiological and pathological processes such as wound healing, platelet activation, angiogenesis and the growth of tumors. Therefore, defining the mechanisms of LPA production and degradation are of interest in understanding the regulation of these processes. Extracellular LPA synthesis is relatively well understood whereas the mechanisms of its degradation are not. One route of LPA degradation is de-phosphorylation. A candidate enzyme is the integral membrane exophosphatase lipid phosphate phosphohydrolase type 1 (LPP1). We report here the development of a mouse wherein the LPP1 gene (Ppap2a) was disrupted. The homozygous mice, which are phenotypically unremarkable, generally lack LPP1 mRNA and multiple tissues exhibit a substantial (35–95%) reduction in LPA phosphatase activity. Compared to wild type littermates, Ppap2atr/tr animals have increased levels of plasma LPA and LPA injected intravenously is metabolized at a four-fold slower rate. Our results demonstrate that LPA is rapidly metabolized in the bloodstream and that LPP1 is an important determinant of this turnover. These results indicate that LPP1 is a catabolic enzyme for LPA in vivo. PMID:19215222

  17. Lysophosphatidic acid mediates myeloid differentiation within the human bone marrow microenvironment.

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    Denis Evseenko

    Full Text Available Lysophosphatidic acid (LPA is a pleiotropic phospholipid present in the blood and certain tissues at high concentrations; its diverse effects are mediated through differential, tissue specific expression of LPA receptors. Our goal was to determine if LPA exerts lineage-specific effects during normal human hematopoiesis. In vitro stimulation of CD34+ human hematopoietic progenitors by LPA induced myeloid differentiation but had no effect on lymphoid differentiation. LPA receptors were expressed at significantly higher levels on Common Myeloid Progenitors (CMP than either multipotent Hematopoietic Stem/Progenitor Cells (HSPC or Common Lymphoid Progenitors (CLP suggesting that LPA acts on committed myeloid progenitors. Functional studies demonstrated that LPA enhanced migration, induced cell proliferation and reduced apoptosis of isolated CMP, but had no effect on either HSPC or CLP. Analysis of adult and fetal human bone marrow sections showed that PPAP2A, (the enzyme which degrades LPA was highly expressed in the osteoblastic niche but not in the perivascular regions, whereas Autotaxin (the enzyme that synthesizes LPA was expressed in perivascular regions of the marrow. We propose that a gradient of LPA with the highest levels in peri-sinusoidal regions and lowest near the endosteal zone, regulates the localization, proliferation and differentiation of myeloid progenitors within the bone marrow marrow.

  18. Frequent mutations of lysophosphatidic acid receptor-1 gene in rat liver tumors

    International Nuclear Information System (INIS)

    Obo, Yumi; Yamada, Takanori; Furukawa, Mami; Hotta, Mayuko; Honoki, Kanya; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2009-01-01

    Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation, migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors, including LPA1 to LPA5. In the present study, to clarify an involvement of LPA1 gene alterations in the development of hepatocellular carcinomas (HCCs) we investigated the LPA1 mutations in rat HCCs induced by exogenous and endogenous liver carcinogenesis models. We induced HCCs in rats with N-nitrosodiethylamine (DEN) and a choline-deficient L-amino acid-defined (CDAA) diet. RNAs were extracted from 15 HCCs induced by DEN and 12 HCCs induced by the CDAA diet. To identify LPA1 mutations, reverse transcription (RT) - polymerase chain reaction (PCR) - single strand conformation polymorphism (SSCP) analysis, followed by nucleotide sequencing, was performed. Missense mutations were detected in 7 out of 15 HCCs (46.7%) induced by DEN. Five out of 12 HCCs (41.7%) induced by the CDAA diet also showed missense mutations. These results demonstrated that mutations in LPA1 gene occur in rat HCCs induced by DEN and the CDAA diet, suggesting that LPA1 mutations may be essentially involved in rat liver carcinogenesis

  19. Differently localized lysophosphatidic acid acyltransferases crucial for triacylglycerol biosynthesis in the oleaginous alga Nannochloropsis.

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    Nobusawa, Takashi; Hori, Koichi; Mori, Hiroshi; Kurokawa, Ken; Ohta, Hiroyuki

    2017-05-01

    The production of renewable bioenergy will be necessary to meet rising global fossil fuel demands. Members of the marine microalgae genus Nannochloropsis produce large quantities of oils (triacylglycerols; TAGs), and this genus is regarded as one of the most promising for biodiesel production. Recent genome sequencing and transcriptomic studies on Nannochloropsis have provided a foundation for understanding its oleaginous trait, but the mechanism underlying oil accumulation remains to be clarified. Here we report Nannochloropsis knock-out strains of four extraplastidic lysophosphatidic acid acyltransferases (LPAT1-LPAT4) that catalyze a major de novo biosynthetic step of TAGs and membrane lipids. We found that the four LPATs are differently involved in lipid metabolic flow in Nannochloropsis. Double knock-outs among the LPATs revealed the pivotal LPATs for TAG biosynthesis, and localization analysis indicated that the stramenopile-specific LPATs (LPAT3 and LPAT4) associated with TAG synthesis reside at the perimeter of lipid droplets. No homologous region has been found with other lipid droplet-associated proteins, however. Lipid droplets are an organelle found in nearly all organisms, and recently they were shown to play important roles in cellular metabolism and signaling. Our results provide direct evidence for the importance of the perimeter of lipid droplet in TAG synthesis in addition to its known role in maintaining TAG stability, and these findings suggest that the oleaginous trait of Nannochloropsis is enabled by the acquisition of LPATs at the perimeter of lipid droplets. © 2017 The Authors. The Plant Journal published by John Wiley & Sons Ltd and Society for Experimental Biology.

  20. Binding of Autotaxin to Integrins Localizes Lysophosphatidic Acid Production to Platelets and Mammalian Cells*

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    Fulkerson, Zachary; Wu, Tao; Sunkara, Manjula; Kooi, Craig Vander; Morris, Andrew J.; Smyth, Susan S.

    2011-01-01

    Autotaxin (ATX) is a secreted lysophospholipase D that generates the bioactive lipid mediator lysophosphatidic acid (LPA). We and others have reported that ATX binds to integrins, but the function of ATX-integrin interactions is unknown. The recently reported crystal structure of ATX suggests a role for the solvent-exposed surface of the N-terminal tandem somatomedin B-like domains in binding to platelet integrin αIIbβ3. The opposite face of the somatomedin B-like domain interacts with the catalytic phosphodiesterase (PDE) domain to form a hydrophobic channel through which lysophospholipid substrates enter and leave the active site. Based on this structure, we hypothesize that integrin-bound ATX can access cell surface substrates and deliver LPA to cell surface receptors. To test this hypothesis, we investigated the integrin selectivity and signaling pathways that promote ATX binding to platelets. We report that both platelet β1 and β3 integrins interact in an activation-dependent manner with ATX via the SMB2 domain. ATX increases thrombin-stimulated LPA production by washed platelets ∼10-fold. When incubated under conditions to promote integrin activation, ATX generates LPA from CHO cells primed with bee venom phospholipase A2, and ATX-mediated LPA production is enhanced more than 2-fold by CHO cell overexpression of integrin β3. The effects of ATX on platelet and cell-associated LPA production, but not hydrolysis of small molecule or detergent-solubilized substrates, are attenuated by point mutations in the SMB2 that impair integrin binding. Integrin binding therefore localizes ATX activity to the cell surface, providing a mechanism to generate LPA in the vicinity of its receptors. PMID:21832043

  1. Lysophosphatidic acid action during early pregnancy in the cow: in vivo and in vitro studies.

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    Woclawek-Potocka, Izabela; Kowalczyk-Zieba, Ilona; Skarzynski, Dariusz Jan

    2010-08-01

    We have previously documented synthesis of lysophosphatidic acid (LPA) in the bovine endometrium and the increased presence of LPA receptor mRNA expression during pregnancy. Therefore, LPA could contribute to early pregnancy establishment in the cow. In the present study, we investigated the effect of intravaginally administered LPA on pregnancy rates and on the plasma levels of progesterone (P4) and prostaglandins (PGs) in heifers. Animals were inseminated and from day 15 to 18 after estrus were treated intravaginally with saline, LPA (1 mg) or LPA receptor blocker (VPC32183; 1 mg). Blood samples were collected on days 0, 6, 12, 15, 16, 17, 18 and 21 after insemination. Pregnancy was confirmed by ultrasonography and per rectum examination on days 30 and 49-50 after insemination. Intravaginal LPA administration increased the plasma P4 and PGE(2) concentrations compared with saline and VPC32183-treated heifers. In the saline and LPA-treated groups, 6 out of 8 heifers were pregnant (75%), whereas the pregnancy rate in the VPC32183-treated heifers was only 37%. We also examined the effects of LPA on PG secretion and PG synthase mRNA expression in stromal and epithelial cells of the bovine endometrium on days 16-18 of pregnancy and the estrous cycle. LPA increased PGE(2) production and PGE(2) synthase (PGES) mRNA expression in stromal cells during the estrous cycle and pregnancy. On Days 16-18 of pregnancy, LPA inhibited PGF(2alpha) production and PGFS mRNA expression in epithelial cells. The results suggest that LPA serves as a luteotropic factor during the estrous cycle and pregnancy, stimulating P4 secretion in vivo and PGE(2) secretion in vitro through activation of PGES mRNA expression in stromal cells. Moreover, during the early pregnancy, LPA decreases PGF(2alpha) synthesis and mRNA expression for PGFS in epithelial cells of the bovine endometrium.

  2. Lysophosphatidic acid produced by hen egg white lysophospholipase D induces vascular development on extraembryonic membranes.

    Science.gov (United States)

    Morishige, Junichi; Uto, Yoshihiro; Hori, Hitoshi; Satouchi, Kiyoshi; Yoshiomoto, Tanihiro; Tokumura, Akira

    2013-03-01

    Lysophosphatidic acid (lysoPtdOH), a lysophospholipid mediator, exerts diverse physiological effects, including angiogenesis, through its specific G-protein-coupled receptors. Previously, we showed that unfertilized hen egg white contains polyunsaturated fatty acid-rich lysoPtdOH and lysophospholipase D (lysoPLD). Here, we examined whether lysoPtdOH was produced by lysoPLD in the presence and absence of a hen fertilized ovum and what the physiological role of lysoPtdOH in hen egg white is. Mass spectrometry showed that fertilized hen egg white contained about 8 μM lysoPtdOH before incubation with an ovum, mainly comprised of 18:1- (12.6 %), 18:2- (37.8 %) and 20:4-molecular species (41.5 %). In an early gestation period, the lysoPtdOH was increased up to 9.6 μM, concomitant with a decrease in the level of polyunsaturated lysophosphatidylcholine (lysoPtdCho). Moreover, lysoPtdOH-degrading activities were found in egg white and the vitelline membrane, showing that these enzymes control lysoPtdOH levels in egg white. In an egg yolk angiogenesis assay, two lysoPtdOH receptor antagonists, Ki16425 and N-palmitoyl serine phosphoric acid (NASP), inhibited blood vessel formation induced by exogenously added 18:1-lysoPtdOH and its precursor lysoPtdCho on the hen yolk sac. Ki16425 and NASP also inhibited blood vessel formation in the chorioallantoic membrane (CAM). Furthermore, the relatively higher levels of LPA₁, LPA₂, LPA₄ and LPA₆ mRNA were present in the yolk sac and CAM. These results suggest that lysoPtdOH produced from lysoPtdCho by the action of lysoPLD in hen egg white is involved in the formation of blood vessel networks through several lysoPtdOH receptors on various extraembryonic membranes, including the yolk sac membrane and CAM.

  3. Lysophosphatidic acid directly induces macrophage-derived foam cell formation by blocking the expression of SRBI.

    Science.gov (United States)

    Chen, Linmu; Zhang, Jun; Deng, Xiao; Liu, Yan; Yang, Xi; Wu, Qiong; Yu, Chao

    2017-09-23

    The leading cause of morbidity and mortality is the result of cardiovascular disease, mainly atherosclerosis. The formation of macrophage foam cells by ingesting ox-LDL and focal retention in the subendothelial space are the hallmarks of the early atherosclerotic lesion. Lysophosphatidic acid (LPA), which is a low-molecular weight lysophospholipid enriched in oxidized LDL, exerts a range of effects on the cardiovascular system. Previous reports show that LPA increases the uptake of ox-LDL to promote the formation of foam cells. However, as the most active component of ox-LDL, there is no report showing whether LPA directly affects foam cell formation. The aim of this study was to investigate the effects of LPA on foam cell formation, as well as to elucidate the underlying mechanism. Oil red O staining and a Cholesterol/cholesteryl ester quantitation assay were used to evaluate foam cell formation in Raw264.7 macrophage cells. We utilized a Western blot and RT-PCR to investigate the relationship between LPA receptors and lipid transport related proteins. We found that LPA promoted foam cell formation, using 200 μM for 24 h. Meanwhile, the expression of the Scavenger receptor BI (SRBI), which promotes the efflux of free cholesterol, was decreased. Furthermore, the LPA 1/3 receptor antagonist Ki16425 significantly abolished the LPA effects, indicating that LPA 1/3 was involved in the foam cell formation and SRBI expression induced by LPA. Additionally, the LPA-induced foam cell formation was blocked with an AKT inhibitor. Our results suggest that LPA-enhanced foam cell formation is mediated by LPA 1/3 -AKT activation and subsequent SRBI expression. Copyright © 2017. Published by Elsevier Inc.

  4. Lysophosphatidic acid (LPA 18:1 transcriptional regulation of primary human gingival fibroblasts

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    D. Roselyn Cerutis

    2014-12-01

    Full Text Available The pleiotropic, bioactive lipid lysophosphatidic acid [(LPA, 1-acyl-sn-glycerol-3-phosphate] exerts critical regulatory actions in physiology and pathophysiology in many systems. It is present in normal bodily fluids, and is elevated in pathology (1. In vivo, “LPA” exists as distinct molecular species, each having a single fatty acid of varying chain length and degree of unsaturation covalently attached to the glycerol backbone via an acyl, alkyl, or alkenyl link. These species differ in affinities for the individual LPA receptors [(LPARs, LPA1-6] and coupling to G proteins (2. However, LPA 18:1 has been and continues to be the most commonly utilized species in reported studies. The actions of “LPA” remain poorly defined in oral biology and pathophysiology. Our laboratory has addressed this knowledge gap by studying in vitro the actions of the major human salivary LPA species [18:1, 18:0, and 16:0 (3] in human oral cells (4–7. This includes gingival fibroblasts (GF, which our flow cytometry data from multiple donors found that they express LPA1-5 (6. We have also reported that these species are ten-fold elevated to pharmacologic levels in the saliva and gingival crevicular fluid obtained from patients with moderate–severe periodontitis (8. As the potential of LPA to regulate transcriptional activity had not been examined in the oral system, this study used whole human genome microarray analysis to test the hypothesis that LPA 18:1-treated human GF would show significant changes in gene transcripts relevant to their biology, wound-healing, and inflammatory responses. LPA 18:1 was found to significantly regulate a large, complex set of genes critical to GF biology in these categories and to periodontal disease. The raw data has been deposited at NCBI's GEO database as record GSE57496.

  5. Lysophosphatidic acid (LPA) 18:1 transcriptional regulation of primary human gingival fibroblasts.

    Science.gov (United States)

    Cerutis, D Roselyn; Weston, Michael D; Ogunleye, Afolabi O; McVaney, Timothy P; Miyamoto, Takanari

    2014-12-01

    The pleiotropic, bioactive lipid lysophosphatidic acid [(LPA), 1-acyl-sn-glycerol-3-phosphate] exerts critical regulatory actions in physiology and pathophysiology in many systems. It is present in normal bodily fluids, and is elevated in pathology (1). In vivo, "LPA" exists as distinct molecular species, each having a single fatty acid of varying chain length and degree of unsaturation covalently attached to the glycerol backbone via an acyl, alkyl, or alkenyl link. These species differ in affinities for the individual LPA receptors [(LPARs), LPA1-6] and coupling to G proteins (2). However, LPA 18:1 has been and continues to be the most commonly utilized species in reported studies. The actions of "LPA" remain poorly defined in oral biology and pathophysiology. Our laboratory has addressed this knowledge gap by studying in vitro the actions of the major human salivary LPA species [18:1, 18:0, and 16:0 (3)] in human oral cells (4-7). This includes gingival fibroblasts (GF), which our flow cytometry data from multiple donors found that they express LPA1-5 (6). We have also reported that these species are ten-fold elevated to pharmacologic levels in the saliva and gingival crevicular fluid obtained from patients with moderate-severe periodontitis (8). As the potential of LPA to regulate transcriptional activity had not been examined in the oral system, this study used whole human genome microarray analysis to test the hypothesis that LPA 18:1-treated human GF would show significant changes in gene transcripts relevant to their biology, wound-healing, and inflammatory responses. LPA 18:1 was found to significantly regulate a large, complex set of genes critical to GF biology in these categories and to periodontal disease. The raw data has been deposited at NCBI's GEO database as record GSE57496.

  6. Autotaxin-lysophosphatidic acid axis is a novel molecular target for lowering intraocular pressure.

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    Padma Iyer

    Full Text Available Primary open-angle glaucoma is the second leading cause of blindness in the United States and is commonly associated with elevated intraocular pressure (IOP resulting from diminished aqueous humor (AH drainage through the trabecular pathway. Developing effective therapies for increased IOP in glaucoma patients requires identification and characterization of molecular mechanisms that regulate IOP and AH outflow. This study describes the identification and role of autotaxin (ATX, a secretory protein and a major source for extracellular lysophosphatidic acid (LPA, in regulation of IOP in a rabbit model. Quantitative proteomics analysis identified ATX as an abundant protein in both human AH derived from non-glaucoma subjects and in AH from different animal species. The lysophospholipase D (LysoPLD activity of ATX was found to be significantly elevated (by ∼1.8 fold; n=20 in AH derived from human primary open angle glaucoma patients as compared to AH derived from age-matched cataract control patients. Immunoblotting analysis of conditioned media derived from primary cultures of human trabecular meshwork (HTM cells has confirmed secretion of ATX and the ability of cyclic mechanical stretch of TM cells to increase the levels of secreted ATX. Topical application of a small molecular chemical inhibitor of ATX (S32826, which inhibited AH LysoPLD activity in vitro (by >90%, led to a dose-dependent and significant decrease of IOP in Dutch-Belted rabbits. Single intracameral injection of S32826 (∼2 µM led to significant reduction of IOP in rabbits, with the ocular hypotensive response lasting for more than 48 hrs. Suppression of ATX expression in HTM cells using small-interfering RNA (siRNA caused a decrease in actin stress fibers and myosin light chain phosphorylation. Collectively, these observations indicate that the ATX-LPA axis represents a potential therapeutic target for lowering IOP in glaucoma patients.

  7. Ginseng pharmacology: a new paradigm based on gintonin-lysophosphatidic acid receptor interactions

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    Seung-Yeol eNah

    2015-10-01

    Full Text Available Ginseng, the root of Panax ginseng, is used as a traditional medicine. Despite the long history of the use of ginseng, there is no specific scientific or clinical rationale for ginseng pharmacology besides its application as a general tonic. The ambiguous description of ginseng pharmacology might be due to the absence of a predominant active ingredient that represents ginseng pharmacology. Recent studies show that ginseng abundantly contains lysophosphatidic acids (LPAs, which are phospholipid-derived growth factor with diverse biological functions including those claimed to be exhibited by ginseng. LPAs in ginseng form a complex with ginseng proteins, which can bind and deliver LPA to its cognate receptors with a high affinity. As a first messenger, gintonin produces second messenger Ca2+ via G protein-coupled LPA receptors. Ca2+ is an intracellular mediator of gintonin and initiates a cascade of amplifications for further intercellular communications by activation of Ca2+-dependent kinases, receptors, gliotransmitter and neurotransmitter release. Ginsenosides, which have been regarded as primary ingredients of ginseng, cannot elicit intracellular [Ca2+]i transients, since they lack specific cell surface receptor. However, ginsenosides exhibit non-specific ion channel and receptor regulations. This is the key characteristic that distinguishes gintonin from ginsenosides. Although the current discourse on ginseng pharmacology is focused on ginsenosides, gintonin can definitely provide a mode of action for ginseng pharmacology that ginsenosides cannot. This review article introduces a novel concept of ginseng ligand-LPA receptor interaction and proposes to establish a paradigm that shifts the focus from ginsenosides to gintonin as a major ingredient representing ginseng pharmacology.

  8. Lysophosphatidic acid rescues bone mesenchymal stem cells from hydrogen peroxide-induced apoptosis.

    Science.gov (United States)

    Wang, Xian-Yun; Fan, Xue-Song; Cai, Lin; Liu, Si; Cong, Xiang-Feng; Chen, Xi

    2015-03-01

    The increase of reactive oxygen species in infracted heart significantly reduces the survival of donor mesenchymal stem cells, thereby attenuating the therapeutic efficacy for myocardial infarction. In our previous study, we demonstrated that lysophosphatidic acid (LPA) protects bone marrow-derived mesenchymal stem cells (BMSCs) against hypoxia and serum deprivation-induced apoptosis. However, whether LPA protects BMSCs from H2O2-induced apoptosis was not examined. In this study, we report that H2O2 induces rat BMSC apoptosis whereas LPA pre-treatment effectively protects BMSCs from H2O2-induced apoptosis. LPA protection of BMSC from the induced apoptosis is mediated mostly through LPA3 receptor. Furthermore, we found that membrane G protein Gi2 and Gi3 are involved in LPA-elicited anti-apoptotic effects through activation of ERK1/2- and PI3 K-pathways. Additionally, H2O2 increases levels of type II of light chain 3B (LC3B II), an autophagy marker, and H2O2-induced autophagy thus protected BMSCs from apoptosis. LPA further increases the expression of LC3B II in the presence of H2O2. In contrast, autophagy flux inhibitor bafilomycin A1 has no effect on LPA's protection of BMSC from H2O2-induced apoptosis. Taken together, our data suggest that LPA rescues H2O2-induced apoptosis mainly by interacting with Gi-coupled LPA3, resulting activation of the ERK1/2- and PI3 K/AKT-pathways and inhibition caspase-3 cleavage, and LPA protection of BMSCs against the apoptosis is independent of it induced autophagy.

  9. Lysophosphatidic Acid Level and the Incidence of Silent Brain Infarction in Patients with Nonvalvular Atrial Fibrillation

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    Li Zhou

    2010-10-01

    Full Text Available Lysophosphatidic acid (LPA, which is proposed to play an important role in normal physiological situations such as wound healing, vascular tone, vascular integrity and reproduction, may be involved in the etiology of some diseases such as atherosclerosis, cancer, obesity or myocardial infarction. Abnormal findings, including silent brain infarction (SBI, are frequently observed by magnetic resonance imaging (MRI in patients with nonvalvular atrial fibrillation (NVAF. However, whether there is a relationship between LPA level and the prevalence of SBI has not been extensively studied. In the present study, the association between them was investigated. 235 patients with NVAF, 116 cases of SBI without NVAF and 120 cases of healthy volunteers (control group, who did not receive any antithrombotic therapy, were enrolled in this study. Plasma LPA levels in the NVAF with SBI group were significantly higher than that in the control group (p < 0.01, NVAF without SBI group (p < 0.01 and SBI without NVAF group (p < 0.01. The LPA levels are lower in the control group than in the NVAF without SBI and SBI without NVAF groups (p < 0.01, however, the latter two groups did not significantly differ from each other for LPA levels (p > 0.05 There were significant differences in the positive rate of platelet activation between each of the groups (p < 0.01. The positive rate of platelet activation was significantly higher in the NVAF with SBI group. We suggest that LPA might be a novel marker for estimation of the status of platelet activation and the risk factor for SBI onset in NVAF patients. We expected that plasma LPA levels could predict the occurrence of SBI in NVAF patients.

  10. Lysophosphatidic acid induces chemotaxis in MC3T3-E1 osteoblastic cells

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    Masiello, Lisa M.; Fotos, Joseph S.; Galileo, Deni S.; Karin, Norm J.

    2006-07-01

    Lysophosphatidic acid (LPA) is a bioactive lipid that has pleiotropic effects on a variety of cell types and enhances the migration of endothelial and cancer cells, but it is not known if this lipid can alter osteoblast motility. We performed transwell migration assays using MC3T3-E1 osteoblastic cells and found LPA to be a potent chemotactic agent. Quantitative time-lapse video analysis of osteoblast migration after wounds were introduced into cell monolayers indicated that LPA stimulated both migration velocity and the average migration distance per cell. LPA also elicited substantial changes in cell shape and actin cytoskeletal structure; lipid-treated cells contained fewer stress fibers and displayed long membrane processes that were enriched in F-actin. Quantitative RT-PCR analysis showed that MC3T3-E1 cells express all four known LPA-specific G protein-coupled receptors (LPA1-LPA4) with a relative mRNA abundance of LPA1 > LPA4 > LPA2 >> LPA3. LPA-induced changes in osteoblast motility and morphology were antagonized by both pertussis toxin and Ki16425, a subtype-specific blocker of LPA1 and LPA3 receptor function. Cell migration in many cell types is linked to changes in intracellular Ca2+. Ki16425 also inhibited LPA-induced Ca2+ signaling in a dose-dependent manner, suggesting a link between LPA-induced Ca2+ transients and osteoblast chemotaxis. Our data show that LPA stimulates MC3T3-E1 osteoblast motility via a mechanism that is linked primarily to the G protein-coupled receptor LPA1.

  11. Lysophosphatidic Acid Up-Regulates Hexokinase II and Glycolysis to Promote Proliferation of Ovarian Cancer Cells.

    Science.gov (United States)

    Mukherjee, Abir; Ma, Yibao; Yuan, Fang; Gong, Yongling; Fang, Zhenyu; Mohamed, Esraa M; Berrios, Erika; Shao, Huanjie; Fang, Xianjun

    2015-09-01

    Lysophosphatidic acid (LPA), a blood-borne lipid mediator, is present in elevated concentrations in ascites of ovarian cancer patients and other malignant effusions. LPA is a potent mitogen in cancer cells. The mechanism linking LPA signal to cancer cell proliferation is not well understood. Little is known about whether LPA affects glucose metabolism to accommodate rapid proliferation of cancer cells. Here we describe that in ovarian cancer cells, LPA enhances glycolytic rate and lactate efflux. A real time PCR-based miniarray showed that hexokinase II (HK2) was the most dramatically induced glycolytic gene to promote glycolysis in LPA-treated cells. Analysis of the human HK2 gene promoter identified the sterol regulatory element-binding protein as the primary mediator of LPA-induced HK2 transcription. The effects of LPA on HK2 and glycolysis rely on LPA2, an LPA receptor subtype overexpressed in ovarian cancer and many other malignancies. We further examined the general role of growth factor-induced glycolysis in cell proliferation. Like LPA, epidermal growth factor (EGF) elicited robust glycolytic and proliferative responses in ovarian cancer cells. Insulin-like growth factor 1 (IGF-1) and insulin, however, potently stimulated cell proliferation but only modestly induced glycolysis. Consistent with their differential effects on glycolysis, LPA and EGF-dependent cell proliferation was highly sensitive to glycolytic inhibition while the growth-promoting effect of IGF-1 or insulin was more resistant. These results indicate that LPA- and EGF-induced cell proliferation selectively involves up-regulation of HK2 and glycolytic metabolism. The work is the first to implicate LPA signaling in promotion of glucose metabolism in cancer cells. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Brown recluse spider (Loxosceles reclusa) venom phospholipase D (PLD) generates lysophosphatidic acid (LPA).

    Science.gov (United States)

    Lee, Sangderk; Lynch, Kevin R

    2005-10-15

    Envenomation by the brown recluse spider (Loxosceles reclusa) may cause local dermonecrosis and, rarely, coagulopathies, kidney failure and death. A venom phospholipase, SMaseD (sphingomyelinase D), is responsible for the pathological manifestations of envenomation. Recently, the recombinant SMaseD from Loxosceles laeta was demonstrated to hydrolyse LPC (lysophosphatidylcholine) to produce LPA (lysophosphatidic acid) and choline. Therefore activation of LPA signalling pathways may be involved in some manifestations of Loxosceles envenomation. To begin investigating this idea, we cloned a full-length cDNA encoding L. reclusa SMaseD. The 305 amino acid sequence of the L. reclusa enzyme is 87, 85 and 60% identical with those of L. arizonica, L. intermedia and L. laeta respectively. The recombinant enzyme expressed in bacteria had broad substrate specificity. The lysophospholipids LPC, LPI (18:1-1-oleyol lysophosphatidylinositol), LPS, LPG (18:1-1-oleoyl-lysophosphatidylglycerol), LBPA (18:1-1-oleoyl-lysobisphosphatidic acid) (all with various acyl chains), lyso-platelet-activating factor (C16:0), cyclic phosphatidic acid and sphingomyelin were hydrolysed, whereas sphingosylphosphorylcholine, PC (phosphatidylcholine; C22:6, C20:4 and C6:0), oxidized PCs and PAF (platelet-activating factor; C16:0) were not hydrolysed. The PAF analogue, edelfosine, inhibited enzyme activity. Recombinant enzyme plus LPC (C18:1) induced the migration of A2058 melanoma cells, and this activity was blocked by the LPA receptor antagonist, VPC32183. The recombinant spider enzyme was haemolytic, but this activity was absent from catalytically inactive H37N (His37-->Asn) and H73N mutants. Our results demonstrate that Loxosceles phospholipase D hydrolyses a wider range of lysophospholipids than previously supposed, and thus the term 'SMaseD' is too limited in describing this enzyme.

  13. Orally administered phosphatidic acids and lysophosphatidic acids ameliorate aspirin-induced stomach mucosal injury in mice.

    Science.gov (United States)

    Tanaka, Tamotsu; Morito, Katsuya; Kinoshita, Masafumi; Ohmoto, Mayumi; Urikura, Mai; Satouchi, Kiyoshi; Tokumura, Akira

    2013-04-01

    Recent investigations revealed that lysophosphatidic acid (LPA), a phospholipid with a growth factor-like activity, plays an important role in the integrity of the gastrointestinal tract epithelium. This paper attempts to clarify the effect of orally administered phosphatidic acid (PA) and LPA on aspirin-induced gastric lesions in mice. Phospholipids, a free fatty acid, a diacylglycerol and a triglyceride at 1 mM (5.7 μmol/kg body weight) or 0.1 mM were orally administered to mice 0.5 h before oral administration of aspirin (1.7 mmol/kg). The total length of lesions formed on the stomach wall was measured as a lesion index. Formation of LPA from PA in the mouse stomach was examined by in vitro (in stomach lavage fluid), ex vivo (in an isolated stomach) and in vivo (in the stomach of a living mouse) examinations of phospholipase activity. Palmitic acid, dioleoyl-glycerol, olive oil and lysophosphatidylcholine did not affect the aspirin-induced lesions. In contrast, phosphatidylcholine (1 mM), LPA (1 mM) and PA (0.1, 1 mM) significantly reduced the lesion index. Evidence for formation of LPA from PA in the stomach by gastric phospholipase A2 was obtained by in vitro, ex vivo and in vivo experiments. An LPA-specific receptor, LPA2, was found to be localized on the gastric surface-lining cells of mice. Pretreatment with PA-rich diets may prevent nonsteroidal anti-inflammatory drug-induced stomach ulcers.

  14. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

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    Dong, Yan; Hirane, Miku; Araki, Mutsumi [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Tsujiuchi, Toshifumi, E-mail: ttujiuch@life.kindai.ac.jp [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan)

    2014-04-04

    Highlights: • LPA{sub 5} inhibits the cell growth and motile activities of 3T3 cells. • LPA{sub 5} suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA{sub 5} on the cell motile activities inhibited by LPA{sub 1} in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA{sub 5} in 3T3 cells. • LPA signaling via LPA{sub 5} acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA{sub 1}–LPA{sub 6}) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA{sub 1} inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA{sub 5} in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA{sub 1} and LPA{sub 5} on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA{sub 5} may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA{sub 1}.

  15. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    International Nuclear Information System (INIS)

    Dong, Yan; Hirane, Miku; Araki, Mutsumi; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2014-01-01

    Highlights: • LPA 5 inhibits the cell growth and motile activities of 3T3 cells. • LPA 5 suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA 5 on the cell motile activities inhibited by LPA 1 in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA 5 in 3T3 cells. • LPA signaling via LPA 5 acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA 1 –LPA 6 ) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA 1 inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA 5 in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA 1 and LPA 5 on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA 5 may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA 1

  16. Clinical significance of plasma lysophosphatidic acid levels in the differential diagnosis of ovarian cancer

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    Yun-Jie Zhang

    2015-01-01

    Full Text Available Objective: To investigate the value of lysophosphatidic acid (LPA in the diagnosis of ovarian cancer. Materials and Methods: We first performed a hospital-based, case-control study involving 123 ovarian cancer patients and 101 benign ovarian tumor patients, and then conducted a meta-analysis with 19 case-control studies to assess the correlation between ovarian cancer and plasma LPA levels. Results: The case-control study results demonstrated that ovarian cancer patients have increased LPA and cancer antigen (CA-125 levels compared to patients with benign ovarian tumor (LPA: Ovarian cancer vs benign ovarian tumor: 5.28 ± 1.52 vs 1.82 ± 0.77 μmol/L; CA-125: Ovarian cancer vs benign ovarian tumor: 87.17 ± 45.81 vs. 14.03 ± 10.14 U/mL, which showed statistically significant differences (both P < 0.05. LPA with advanced sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of diagnosis excelled CA-125 in the diagnosis of ovarian cancer (both P < 0.05. The areas under the receiver operating characteristic (ROC curve in the diagnosis of ovarian cancer (LPA: 0.983; CA-125: 0.910 were statistically significant compared with the reference (both P < 0.001 and the difference of the areas of ROC curve between LPA and CA-125 in the diagnosis of ovarian cancer showed statistically significant difference (P < 0.05. The meta-analysis results suggested that plasma LPA levels were higher in ovarian cancer tissues than in benign tissues (standardized mean difference (SMD =2.36, 95% confidence interval (CI: 1.61-3.11, P < 0.001 and normal tissues (SMD = 2.32, 95% CI: 1.77-2.87, P < 0.001. Conclusion: LPA shows greater value in the diagnosis of ovarian cancer compared to CA-125 and may be employed as a biological index to diagnose ovarian cancer.

  17. Lysophosphatidic Acid Receptor 4 Activation Augments Drug Delivery in Tumors by Tightening Endothelial Cell-Cell Contact.

    Science.gov (United States)

    Takara, Kazuhiro; Eino, Daisuke; Ando, Koji; Yasuda, Daisuke; Naito, Hisamichi; Tsukada, Yohei; Iba, Tomohiro; Wakabayashi, Taku; Muramatsu, Fumitaka; Kidoya, Hiroyasu; Fukuhara, Shigetomo; Mochizuki, Naoki; Ishii, Satoshi; Kishima, Haruhiko; Takakura, Nobuyuki

    2017-08-29

    Vascular normalization in tumors may improve drug delivery and anti-tumor immunity. Angiogenesis inhibitors induce hypoxia, which may facilitate malignant progression; therefore, we investigated other methods to promote vascular maturation. Here, we show that lysophosphatidic acid (LPA) enhances blood flow by promoting fine vascular networks, thereby improving vascular permeability and suppressing tumor growth when combined with anti-cancer drug treatment. Six different G protein-coupled receptors have been identified as LPA receptors (LPA1-6). In studies using mutant mice, we found that LPA4 is involved in vascular network formation. LPA4 activation induces circumferential actin bundling beneath the cell membrane and enhances linear adherens junction formation by VE-cadherin in endothelial cells. Therefore, we conclude that activation of LPA4 is a promising approach for vascular regulation. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Lysophosphatidic Acid Receptor 4 Activation Augments Drug Delivery in Tumors by Tightening Endothelial Cell-Cell Contact

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    Kazuhiro Takara

    2017-08-01

    Full Text Available Vascular normalization in tumors may improve drug delivery and anti-tumor immunity. Angiogenesis inhibitors induce hypoxia, which may facilitate malignant progression; therefore, we investigated other methods to promote vascular maturation. Here, we show that lysophosphatidic acid (LPA enhances blood flow by promoting fine vascular networks, thereby improving vascular permeability and suppressing tumor growth when combined with anti-cancer drug treatment. Six different G protein-coupled receptors have been identified as LPA receptors (LPA1–6. In studies using mutant mice, we found that LPA4 is involved in vascular network formation. LPA4 activation induces circumferential actin bundling beneath the cell membrane and enhances linear adherens junction formation by VE-cadherin in endothelial cells. Therefore, we conclude that activation of LPA4 is a promising approach for vascular regulation.

  19. Autotaxin activity increases locally following lung injury, but is not required for pulmonary lysophosphatidic acid production or fibrosis

    Science.gov (United States)

    Black, Katharine E.; Berdyshev, Evgeny; Bain, Gretchen; Castelino, Flavia V.; Shea, Barry S.; Probst, Clemens K.; Fontaine, Benjamin A.; Bronova, Irina; Goulet, Lance; Lagares, David; Ahluwalia, Neil; Knipe, Rachel S.; Natarajan, Viswanathan; Tager, Andrew M.

    2016-01-01

    Lysophosphatidic acid (LPA) is an important mediator of pulmonary fibrosis. In blood and multiple tumor types, autotaxin produces LPA from lysophosphatidylcholine (LPC) via lysophospholipase D activity, but alternative enzymatic pathways also exist for LPA production. We examined the role of autotaxin (ATX) in pulmonary LPA production during fibrogenesis in a bleomycin mouse model. We found that bleomycin injury increases the bronchoalveolar lavage (BAL) fluid levels of ATX protein 17-fold. However, the LPA and LPC species that increase in BAL of bleomycin-injured mice were discordant, inconsistent with a substrate-product relationship between LPC and LPA in pulmonary fibrosis. LPA species with longer chain polyunsaturated acyl groups predominated in BAL fluid after bleomycin injury, with 22:5 and 22:6 species accounting for 55 and 16% of the total, whereas the predominant BAL LPC species contained shorter chain, saturated acyl groups, with 16:0 and 18:0 species accounting for 56 and 14% of the total. Further, administration of the potent ATX inhibitor PAT-048 to bleomycin-challenged mice markedly decreased ATX activity systemically and in the lung, without effect on pulmonary LPA or fibrosis. Therefore, alternative ATX-independent pathways are likely responsible for local generation of LPA in the injured lung. These pathways will require identification to therapeutically target LPA production in pulmonary fibrosis.—Black, K. E., Berdyshev, E., Bain, G., Castelino, F. V., Shea, B. S., Probst, C. K., Fontaine, B. A., Bronova, I., Goulet, L., Lagares, D., Ahluwalia, N., Knipe, R. S., Natarajan, V., Tager, A. M. Autotaxin activity increases locally following lung injury, but is not required for pulmonary lysophosphatidic acid production or fibrosis. PMID:27006447

  20. Lysophosphatidic acid enhances vascular endothelial growth factor-C expression in human prostate cancer PC-3 cells.

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    Chuan-En Lin

    Full Text Available Clinical evidence suggests that lymphangiogenesis and lymphatic metastasis are important processes during the progression of prostate cancer. Vascular endothelial growth factor (VEGF-C was shown to be a key regulator in these processes. Our previous studies demonstrated that lysophosphatidic acid (LPA, a low-molecular-weight lipid growth factor, enhances VEGF-C expression in human endothelial cells. We previously demonstrated that the LPA receptor plays an important role in lymphatic development in zebrafish embryos. However, the effects of LPA on VEGF-C expression in prostate cancer are not known. Herein, we demonstrate that LPA up-regulated VEGF-C expression in three different human prostate cancer cell lines. In PC-3 human prostate cancer cells, the enhancing effects of LPA were mediated through both LPA1 and LPA3. In addition, reactive oxygen species (ROS production and lens epithelium-derived growth factor (LEDGF expression were involved in LPA(1/3-dependent VEGF-C expression. Furthermore, autotaxin (ATX, an enzyme responsible for LPA synthesis, also participates in regulating VEGF-C expression. By interrupting LPA(1/3 of PC-3, conditioned medium (CM -induced human umbilical vein endothelial cell (HUVEC lymphatic markers expression was also blocked. In summary, we found that LPA enhances VEGF-C expression through activating LPA(1/3-, ROS-, and LEDGF-dependent pathways. These novel findings could potentially shed light on developing new strategies for preventing lymphatic metastasis of prostate cancer.

  1. Phosphorylation of CREB, a cyclic AMP responsive element binding protein, contributes partially to lysophosphatidic acid-induced fibroblast cell proliferation

    International Nuclear Information System (INIS)

    Kwon, Yong-Jun; Sun, Yuanjie; Kim, Nam-Ho; Huh, Sung-Oh

    2009-01-01

    Lysophospholipids regulate a wide array of biological processes including cell survival and proliferation. In our previous studies, we found that in addition to SRE, CRE is required for maximal c-fos promoter activation triggered by lysophosphatidic acid (LPA). c-fos is an early indicator of various cells into the cell cycle after mitogenic stimulation. However, role of CREB activation in LPA-stimulated proliferation has not been elucidated yet. Here, we investigate how LPA induces proliferation in Rat-2 fibroblast cell via CREB activation. We found that total cell number and BrdU-positive cells were increased by LPA. Moreover, levels of c-fos mRNA and cyclin D1 protein were increased via LPA-induced CREB phosphorylation. Furthermore, LPA-induced Rat-2 cell proliferation was decreased markedly by ERK inhibitor (U0126) and partially by MSK inhibitor (H89). Taken together, these results suggest that CREB activation could partially up-regulate accumulation of cyclin D1 protein level and proliferation of LPA-stimulated Rat-2 fibroblast cells.

  2. Lysophosphatidic Acid Signaling Axis Mediates Ceramide 1-Phosphate-Induced Proliferation of C2C12 Myoblasts.

    Science.gov (United States)

    Bernacchioni, Caterina; Cencetti, Francesca; Ouro, Alberto; Bruno, Marina; Gomez-Muñoz, Antonio; Donati, Chiara; Bruni, Paola

    2018-01-04

    Sphingolipids are not only crucial for membrane architecture but act as critical regulators of cell functions. The bioactive sphingolipid ceramide 1-phosphate (C1P), generated by the action of ceramide kinase, has been reported to stimulate cell proliferation, cell migration and to regulate inflammatory responses via activation of different signaling pathways. We have previously shown that skeletal muscle is a tissue target for C1P since the phosphosphingolipid plays a positive role in myoblast proliferation implying a role in muscle regeneration. Skeletal muscle displays strong capacity of regeneration thanks to the presence of quiescent adult stem cells called satellite cells that upon trauma enter into the cell cycle and start proliferating. However, at present, the exact molecular mechanism by which C1P triggers its mitogenic effect in myoblasts is lacking. Here, we report for the first time that C1P stimulates C2C12 myoblast proliferation via lysophosphatidic acid (LPA) signaling axis. Indeed, C1P subsequently to phospholipase A2 activation leads to LPA₁ and LPA₃ engagement, which in turn drive Akt (protein kinase B) and ERK1/2 (extracellular signal-regulated kinases 1/2) activation, thus stimulating DNA synthesis. The present findings shed new light on the key role of bioactive sphingolipids in skeletal muscle and provide further support to the notion that these pleiotropic molecules might be useful therapeutic targets for skeletal muscle regeneration.

  3. Co-ordinate regulation of growth factor receptors and lipid phosphate phosphatase-1 controls cell activation by exogenous lysophosphatidate.

    Science.gov (United States)

    Pilquil, C; Ling, Z C; Singh, I; Buri, K; Zhang, Q X; Brindley, D N

    2001-11-01

    The serum-derived lipid growth factors, lysophosphatidate (LPA) and sphingosine 1-phosphate (S1P), activate cells selectively through different members of a family of endothelial differentiation gene (EDG) receptors. Activation of EDG receptors by LPA and S1P provides a variety of signalling cascades depending upon the G-protein coupling of the different EDG receptors. This leads to chemotactic and mitogenic responses, which are important in wound healing. For example, LPA stimulates fibroblast division and S1P stimulates the chemotaxis and division of endothelial cells leading to angiogenesis. Counteracting these effects of LPA and S1P, are the actions of lipid phosphate phosphatases (LPP, or phosphatidate phosphohydrolases, Type 2). The isoform LPP-1 is expressed in the plasma membrane with its active site outside the cell. This enzyme is responsible for 'ecto-phosphatase' activity leading to the degradation of exogenous lipid phosphate mediators, particularly LPA. Expression of LPP-1 decreases cell activation by exogenous LPA. The mechanism for this is controversial and several mechanisms have been proposed. Evidence will be presented that the LPPs cross-talk with EDG and other growth factor receptors, thus, regulating the responses of the cells to lipid phosphate mediators of signal transduction.

  4. Dual Action of Lysophosphatidate-Functionalised Titanium: Interactions with Human (MG63 Osteoblasts and Methicillin Resistant Staphylococcus aureus.

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    Mette Elena Skindersoe

    Full Text Available Titanium (Ti is a widely used material for surgical implants; total joint replacements (TJRs, screws and plates for fixing bones and dental implants are forged from Ti. Whilst Ti integrates well into host tissue approximately 10% of TJRs will fail in the lifetime of the patient through a process known as aseptic loosening. These failures necessitate revision arthroplasties which are more complicated and costly than the initial procedure. Finding ways of enhancing early (osseointegration of TJRs is therefore highly desirable and continues to represent a research priority in current biomaterial design. One way of realising improvements in implant quality is to coat the Ti surface with small biological agents known to support human osteoblast formation and maturation at Ti surfaces. Lysophosphatidic acid (LPA and certain LPA analogues offer potential solutions as Ti coatings in reducing aseptic loosening. Herein we present evidence for the successful bio-functionalisation of Ti using LPA. This modified Ti surface heightened the maturation of human osteoblasts, as supported by increased expression of alkaline phosphatase. These functionalised surfaces also deterred the attachment and growth of Staphylococcus aureus, a bacterium often associated with implant failures through sepsis. Collectively we provide evidence for the fabrication of a dual-action Ti surface finish, a highly desirable feature towards the development of next-generation implantable devices.

  5. Constitutive lymphocyte transmigration across the basal lamina of high endothelial venules is regulated by the autotaxin/lysophosphatidic acid axis.

    Science.gov (United States)

    Bai, Zhongbin; Cai, Linjun; Umemoto, Eiji; Takeda, Akira; Tohya, Kazuo; Komai, Yutaka; Veeraveedu, Punniyakoti Thanikachalam; Hata, Erina; Sugiura, Yuki; Kubo, Akiko; Suematsu, Makoto; Hayasaka, Haruko; Okudaira, Shinichi; Aoki, Junken; Tanaka, Toshiyuki; Albers, Harald M H G; Ovaa, Huib; Miyasaka, Masayuki

    2013-03-01

    Lymphocyte extravasation from the high endothelial venules (HEVs) of lymph nodes is crucial for the maintenance of immune homeostasis, but its molecular mechanism remains largely unknown. In this article, we report that lymphocyte transmigration across the basal lamina of the HEVs is regulated, at least in part, by autotaxin (ATX) and its end-product, lysophosphatidic acid (LPA). ATX is an HEV-associated ectoenzyme that produces LPA from lysophosphatidylcholine (LPC), which is abundant in the systemic circulation. In agreement with selective expression of ATX in HEVs, LPA was constitutively and specifically detected on HEVs. In vivo, inhibition of ATX impaired the lymphocyte extravasation from HEVs, inducing lymphocyte accumulation within the endothelial cells (ECs) and sub-EC compartment; this impairment was abrogated by LPA. In vitro, both LPA and LPC induced a marked increase in the motility of HEV ECs; LPC's effect was abrogated by ATX inhibition, whereas LPA's effect was abrogated by ATX/LPA receptor inhibition. In an in vitro transmigration assay, ATX inhibition impaired the release of lymphocytes that had migrated underneath HEV ECs, and these defects were abrogated by LPA. This effect of LPA was dependent on myosin II activity in the HEV ECs. Collectively, these results strongly suggest that HEV-associated ATX generates LPA locally; LPA, in turn, acts on HEV ECs to increase their motility, promoting dynamic lymphocyte-HEV interactions and subsequent lymphocyte transmigration across the basal lamina of HEVs at steady state.

  6. Involvement of aberrant DNA methylation on reduced expression of lysophosphatidic acid receptor-1 gene in rat tumor cell lines

    International Nuclear Information System (INIS)

    Tsujiuchi, Toshifumi; Shimizu, Kyoko; Onishi, Mariko; Sugata, Eriko; Fujii, Hiromasa; Mori, Toshio; Honoki, Kanya; Fukushima, Nobuyuki

    2006-01-01

    Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation, migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. Recently, it has been reported that alterations of LPA receptor expression might be important in the malignant transformation of tumor cells. Therefore, to assess an involvement of DNA methylation in reduced expression of the LPA receptor-1 (lpa1) gene, we investigated the expression of the lpa1 gene and its DNA methylation patterns in rat tumor cell lines. Both rat brain-derived neuroblastoma B103 and liver-derived hepatoma RH7777 cells used in this study indicated no expression of lpa1. For the analysis of methylation status, bisulfite sequencing was performed with B103 and RH7777 cells, comparing with other lpa1 expressed cells and normal tissues of brain and liver. The lpa1 expressed cells and tissues were all unmethylated in this region of lpa1. In contrast, both B103 and RH7777 cells were highly methylated, correlating with reduced expression of the lpa1. Treatment with 5-aza 2'-deoxycytidine induced expression of lpa1 gene in B103 and RH7777 cells after 24 h. In RH7777 cells treated with 5-aza 2'-deoxycytidine, stress fiber formation was also observed in response to LPA in RH7777 cells, but not in untreated RH7777 cells. These results suggest that aberrant DNA methylation of the lpa1 gene may be involved in its reduced expression in rat tumor cells

  7. Clinical significance and correlation of the level change of plasma lysophosphatidic acid in patients before and during radiotherapy

    International Nuclear Information System (INIS)

    Yu Liang; Li Hong; Zhu Shengjie

    2011-01-01

    Objective: To investigate the effects of radiotherapy on the level of lysophosphatidic acid (LPA) in different patients. Methods: Three groups of patients (metastatic brain tumor group, non-brain tumor group and primary brain tumor group) were given external irradiation (by linear accelerator). LPA level, white blood cell count and platelet count in the blood plasma were evaluated pre-irradiation and after irradiation with 40 Gy and 60 Gy respectively. Results: The LPA level decreased gradually as irradiation doses increase in metastatic brain tumor group non-brain tumor group (after irradiation with 60 Gy 0.05), and neoplasm volume changed little. White blood cell count and platelet count gradually decreased with the increasing irradiation doses in metastatic brain tumor group and primary brain tumor group, but there was no significant correlation to LPA level. However, there was a negative correlation to LPA level in non-brain tumor group (r=-0.285 and r=-0.237, both P<0.05 ). Conclusions: There is a negative correlation between radiotherapy dose and LPA level in metastatic brain tumor patients and non-brain tumor patients. LPA level could be used as a predictor of the effect of the radiotherapy in tumor treatment. (authors)

  8. Kinetic Analysis of Autotaxin Reveals Substrate-specific Catalytic Pathways and a Mechanism for Lysophosphatidic Acid Distribution*

    Science.gov (United States)

    Saunders, Lauren P.; Cao, Wenxiang; Chang, William C.; Albright, Ronald A.; Braddock, Demetrios T.; De La Cruz, Enrique M.

    2011-01-01

    Autotaxin (ATX) is a secreted lysophospholipase D that hydrolyzes lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), initiating signaling cascades leading to cancer metastasis, wound healing, and angiogenesis. Knowledge of the pathway and kinetics of LPA synthesis by ATX is critical for developing quantitative physiological models of LPA signaling. We measured the individual rate constants and pathway of the LPA synthase cycle of ATX using the fluorescent lipid substrates FS-3 and 12-(N-methyl-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl))-LPC. FS-3 binds rapidly (k1 ≥500 μm−1 s−1) and is hydrolyzed slowly (k2 = 0.024 s−1). Release of the first hydrolysis product is random and rapid (≥1 s−1), whereas release of the second is slow and rate-limiting (0.005–0.007 s−1). Substrate binding and hydrolysis are slow and rate-limiting with LPC. Product release is sequential with choline preceding LPA. The catalytic pathway and kinetics depend strongly on the substrate, suggesting that ATX kinetics could vary for the various in vivo substrates. Slow catalysis with LPC reveals the potential for LPA signaling to spread to cells distal to the site of LPC substrate binding by ATX. An ATX mutant in which catalytic threonine at position 210 is replaced with alanine binds substrate weakly, favoring a role for Thr-210 in binding as well as catalysis. FTY720P, the bioactive form of a drug currently used to treat multiple sclerosis, inhibits ATX in an uncompetitive manner and slows the hydrolysis reaction, suggesting that ATX inhibition plays a significant role in lymphocyte immobilization in FTY720P-based therapeutics. PMID:21719699

  9. Lysophosphatidic Acid Inhibits Insulin Signaling in Primary Rat Hepatocytes via the LPA3 Receptor Subtype and is Increased in Obesity

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    Susann Fayyaz

    2017-09-01

    Full Text Available Background/Aims: Obesity is a main risk factor for the development of hepatic insulin resistance and it is accompanied by adipocyte hypertrophy and an elevated expression of different adipokines such as autotaxin (ATX. ATX converts lysophosphatidylcholine to lysophosphatidic acid (LPA and acts as the main producer of extracellular LPA. This bioactive lipid regulates a broad range of physiological and pathological responses by activation of LPA receptors (LPA1-6. Methods: The activation of phosphatidylinositide 3-kinases (PI3K signaling (Akt and GSK-3ß was analyzed via western blotting in primary rat hepatocytes. Incorporation of glucose into glycogen was measured by using radio labeled glucose. Real-time PCR analysis and pharmacological modulation of LPA receptors were performed. Human plasma LPA levels of obese (BMI > 30, n = 18 and normal weight individuals (BMI 18.5-25, n = 14 were analyzed by liquid chromatography tandem-mass spectrometry (LC-MS/MS. Results: Pretreatment of primary hepatocytes with LPA resulted in an inhibition of insulin-mediated Gck expression, PI3K activation and glycogen synthesis. Pharmacological approaches revealed that the LPA3-receptor subtype is responsible for the inhibitory effect of LPA on insulin signaling. Moreover, human plasma LPA concentrations (16: 0 LPA of obese participants (BMI > 30 are significantly elevated in comparison to normal weight individuals (BMI 18.5-25. Conclusion: LPA is able to interrupt insulin signaling in primary rat hepatocytes via the LPA3 receptor subtype. Moreover, the bioactive lipid LPA (16: 0 is increased in obesity.

  10. Autotaxin and lysophosphatidic acid1 receptor-mediated demyelination of dorsal root fibers by sciatic nerve injury and intrathecal lysophosphatidylcholine

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    Aoki Junken

    2010-11-01

    Full Text Available Abstract Background Although neuropathic pain is frequently observed in demyelinating diseases such as Guillain-Barré syndrome and multiple sclerosis, the molecular basis for the relationship between demyelination and neuropathic pain behaviors is poorly understood. Previously, we found that lysophosphatidic acid receptor (LPA1 signaling initiates sciatic nerve injury-induced neuropathic pain and demyelination. Results In the present study, we have demonstrated that sciatic nerve injury induces marked demyelination accompanied by myelin-associated glycoprotein (MAG down-regulation and damage of Schwann cell partitioning of C-fiber-containing Remak bundles in the sciatic nerve and dorsal root, but not in the spinal nerve. Demyelination, MAG down-regulation and Remak bundle damage in the dorsal root were abolished in LPA1 receptor-deficient (Lpar1-/- mice, but these alterations were not observed in sciatic nerve. However, LPA-induced demyelination in ex vivo experiments was observed in the sciatic nerve, spinal nerve and dorsal root, all which express LPA1 transcript and protein. Nerve injury-induced dorsal root demyelination was markedly attenuated in mice heterozygous for autotaxin (atx+/-, which converts lysophosphatidylcholine (LPC to LPA. Although the addition of LPC to ex vivo cultures of dorsal root fibers in the presence of recombinant ATX caused potent demyelination, it had no significant effect in the absence of ATX. On the other hand, intrathecal injection of LPC caused potent dorsal root demyelination, which was markedly attenuated or abolished in atx+/- or Lpar1-/- mice. Conclusions These results suggest that LPA, which is converted from LPC by ATX, activates LPA1 receptors and induces dorsal root demyelination following nerve injury, which causes neuropathic pain.

  11. CD14 is a key mediator of both lysophosphatidic acid and lipopolysaccharide induction of foam cell formation.

    Science.gov (United States)

    An, Dong; Hao, Feng; Zhang, Fuqiang; Kong, Wei; Chun, Jerold; Xu, Xuemin; Cui, Mei-Zhen

    2017-09-01

    Macrophage uptake of oxidized low-density lipoprotein (oxLDL) plays an important role in foam cell formation and the pathogenesis of atherosclerosis. We report here that lysophosphatidic acid (LPA) enhances lipopolysaccharide (LPS)-induced oxLDL uptake in macrophages. Our data revealed that both LPA and LPS highly induce the CD14 expression at messenger RNA and protein levels in macrophages. The role of CD14, one component of the LPS receptor cluster, in LPA-induced biological functions has been unknown. We took several steps to examine the role of CD14 in LPA signaling pathways. Knockdown of CD14 expression nearly completely blocked LPA/LPS-induced oxLDL uptake in macrophages, demonstrating for the first time that CD14 is a key mediator responsible for both LPA- and LPS-induced oxLDL uptake/foam cell formation. To determine the molecular mechanism mediating CD14 function, we demonstrated that both LPA and LPS significantly induce the expression of scavenger receptor class A type I (SR-AI), which has been implicated in lipid uptake process, and depletion of CD14 levels blocked LPA/LPS-induced SR-AI expression. We further showed that the SR-AI-specific antibody, which quenches SR-AI function, blocked LPA- and LPS-induced foam cell formation. Thus, SR-AI is the downstream mediator of CD14 in regulating LPA-, LPS-, and LPA/LPS-induced foam cell formation. Taken together, our results provide the first experimental evidence that CD14 is a novel connecting molecule linking both LPA and LPS pathways and is a key mediator responsible for LPA/LPS-induced foam cell formation. The LPA/LPS-CD14-SR-AI nexus might be the new convergent pathway, contributing to the worsening of atherosclerosis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Lysophosphatidic acid-induced increase in adult hippocampal neurogenesis facilitates the forgetting of cocaine-contextual memory.

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    Ladrón de Guevara-Miranda, David; Moreno-Fernández, Román Darío; Gil-Rodríguez, Sara; Rosell-Valle, Cristina; Estivill-Torrús, Guillermo; Serrano, Antonia; Pavón, Francisco J; Rodríguez de Fonseca, Fernando; Santín, Luis J; Castilla-Ortega, Estela

    2018-02-26

    Erasing memories of cocaine-stimuli associations might have important clinical implications for addiction therapy. Stimulating hippocampal plasticity by enhancing adult hippocampal neurogenesis (AHN) is a promising strategy because the addition of new neurons may not only facilitate new learning but also modify previous connections and weaken retrograde memories. To investigate whether increasing AHN prompted the forgetting of previous contextual cocaine associations, mice trained in a cocaine-induced conditioned place preference (CPP) paradigm were administered chronic intracerebroventricular infusions of lysophosphatidic acid (LPA, an endogenous lysophospholipid with pro-neurogenic actions), ki16425 (an LPA 1/3 receptor antagonist) or a vehicle solution, and they were tested 23 days later for CPP retention and extinction. The results of immunohistochemical experiments showed that the LPA-treated mice exhibited reduced long-term CPP retention and an approximately twofold increase in the number of adult-born hippocampal cells that differentiated into mature neurons. Importantly, mediation analyses confirmed a causal role of AHN in reducing CPP maintenance. In contrast, the ki16425-treated mice displayed aberrant responses, with initially decreased CPP retention that progressively increased across the extinction sessions, leading to no effect on AHN. The pharmacological treatments did not affect locomotion or general exploratory or anxiety-like responses. In a second experiment, normal and LPA 1 -receptor-deficient mice were acutely infused with LPA, which revealed that LPA 1 -mediated signaling was required for LPA-induced proliferative actions. These results suggest that the LPA/LPA 1 pathway acts as a potent in vivo modulator of AHN and highlight the potential usefulness of pro-AHN strategies to treat aberrant cognition in those addicted to cocaine. © 2018 Society for the Study of Addiction.

  13. Lysophosphatidic Acid Receptor–2 Deficiency Confers Protection against Bleomycin-Induced Lung Injury and Fibrosis in Mice

    Science.gov (United States)

    Huang, Long Shuang; Fu, Panfeng; Patel, Priya; Harijith, Anantha; Sun, Tianjiao; Zhao, Yutong; Garcia, Joe G. N.; Chun, Jerold

    2013-01-01

    Idiopathic pulmonary fibrosis is a devastating disease characterized by alveolar epithelial cell injury, the accumulation of fibroblasts/myofibroblasts, and the deposition of extracellular matrix proteins. Lysophosphatidic acid (LPA) signaling through its G protein–coupled receptors is critical for its various biological functions. Recently, LPA and LPA receptor 1 were implicated in lung fibrogenesis. However, the role of other LPA receptors in fibrosis remains unclear. Here, we use a bleomycin-induced pulmonary fibrosis model to investigate the roles of LPA2 in pulmonary fibrogenesis. In the present study, we found that LPA2 knockout (Lpar2−/−) mice were protected against bleomycin-induced lung injury, fibrosis, and mortality, compared with wild-type control mice. Furthermore, LPA2 deficiency attenuated the bleomycin-induced expression of fibronectin (FN), α–smooth muscle actin (α-SMA), and collagen in lung tissue, as well as levels of IL-6, transforming growth factor–β (TGF-β), and total protein in bronchoalveolar lavage fluid. In human lung fibroblasts, the knockdown of LPA2 attenuated the LPA-induced expression of TGF-β1 and the differentiation of lung fibroblasts to myofibroblasts, resulting in the decreased expression of FN, α-SMA, and collagen, as well as decreased activation of extracellular regulated kinase 1/2, Akt, Smad3, and p38 mitogen-activated protein kinase. Moreover, the knockdown of LPA2 with small interfering RNA also mitigated the TGF-β1–induced differentiation of lung fibroblasts. In addition, LPA2 deficiency significantly attenuated the bleomycin-induced apoptosis of alveolar and bronchial epithelial cells in the mouse lung. Together, our data indicate that the knockdown of LPA2 attenuated bleomycin-induced lung injury and pulmonary fibrosis, and this may be related to an inhibition of the LPA-induced expression of TGF-β and the activation and differentiation of fibroblasts. PMID:23808384

  14. Cyclic phosphatidic acid and lysophosphatidic acid induce hyaluronic acid synthesis via CREB transcription factor regulation in human skin fibroblasts.

    Science.gov (United States)

    Maeda-Sano, Katsura; Gotoh, Mari; Morohoshi, Toshiro; Someya, Takao; Murofushi, Hiromu; Murakami-Murofushi, Kimiko

    2014-09-01

    Cyclic phosphatidic acid (cPA) is a naturally occurring phospholipid mediator and an analog of the growth factor-like phospholipid lysophosphatidic acid (LPA). cPA has a unique cyclic phosphate ring at the sn-2 and sn-3 positions of its glycerol backbone. We showed before that a metabolically stabilized cPA derivative, 2-carba-cPA, relieved osteoarthritis pathogenesis in vivo and induced hyaluronic acid synthesis in human osteoarthritis synoviocytes in vitro. This study focused on hyaluronic acid synthesis in human fibroblasts, which retain moisture and maintain health in the dermis. We investigated the effects of cPA and LPA on hyaluronic acid synthesis in human fibroblasts (NB1RGB cells). Using particle exclusion and enzyme-linked immunosorbent assays, we found that both cPA and LPA dose-dependently induced hyaluronic acid synthesis. We revealed that the expression of hyaluronan synthase 2 messenger RNA and protein is up-regulated by cPA and LPA treatment time dependently. We then characterized the signaling pathways up-regulating hyaluronic acid synthesis mediated by cPA and LPA in NB1RGB cells. Pharmacological inhibition and reporter gene assays revealed that the activation of the LPA receptor LPAR1, Gi/o protein, phosphatidylinositol-3 kinase (PI3K), extracellular-signal-regulated kinase (ERK), and cyclic adenosine monophosphate response element-binding protein (CREB) but not nuclear factor κB induced hyaluronic acid synthesis by the treatment with cPA and LPA in NB1RGB cells. These results demonstrate for the first time that cPA and LPA induce hyaluronic acid synthesis in human skin fibroblasts mainly through the activation of LPAR1-Gi/o followed by the PI3K, ERK, and CREB signaling pathway. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Role of lysophosphatidic acid receptor LPA2 in the development of allergic airway inflammation in a murine model of asthma

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    Chun Jerold

    2009-11-01

    Full Text Available Abstract Background Lysophosphatidic acid (LPA plays a critical role in airway inflammation through G protein-coupled LPA receptors (LPA1-3. We have demonstrated that LPA induced cytokine and lipid mediator release in human bronchial epithelial cells. Here we provide evidence for the role of LPA and LPA receptors in Th2-dominant airway inflammation. Methods Wild type, LPA1 heterozygous knockout mice (LPA1+/-, and LPA2 heterozygous knockout mice (LPA2+/- were sensitized with inactivated Schistosoma mansoni eggs and local antigenic challenge with Schistosoma mansoni soluble egg Ag (SEA in the lungs. Bronchoalveolar larvage (BAL fluids and lung tissues were collected for analysis of inflammatory responses. Further, tracheal epithelial cells were isolated and challenged with LPA. Results BAL fluids from Schistosoma mansoni egg-sensitized and challenged wild type mice (4 days of challenge showed increase of LPA level (~2.8 fold, compared to control mice. LPA2+/- mice, but not LPA1+/- mice, exposed to Schistosoma mansoni egg revealed significantly reduced cell numbers and eosinophils in BAL fluids, compared to challenged wild type mice. Both LPA2+/- and LPA1+/- mice showed decreases in bronchial goblet cells. LPA2+/- mice, but not LPA1+/- mice showed the decreases in prostaglandin E2 (PGE2 and LPA levels in BAL fluids after SEA challenge. The PGE2 production by LPA was reduced in isolated tracheal epithelial cells from LPA2+/- mice. These results suggest that LPA and LPA receptors are involved in Schistosoma mansoni egg-mediated inflammation and further studies are proposed to understand the role of LPA and LPA receptors in the inflammatory process.

  16. A Major Human Oral Lysophosphatidic Acid Species, LPA 18:1, Regulates Novel Genes in Human Gingival Fibroblasts.

    Science.gov (United States)

    Cerutis, D Roselyn; Weston, Michael D; Alnouti, Yazen; Bathena, Sai P; Nunn, Martha E; Ogunleye, Afolabi O; McVaney, Timothy P; Headen, Karmel V; Miyamoto, Takanari

    2015-05-01

    The small bioactive lipid lysophosphatidic acid (LPA) plays critical roles in both normal physiology and inflammation in many systems. However, its actions are just beginning to be defined in oral biology and pathophysiology. Microarray analysis was used to test the hypothesis that human gingival fibroblasts (GFs) would show significant changes in wound-healing and inflammation-related gene transcripts in response to a major human salivary and gingival crevicular fluid LPA species, 18:1, and that they would express transcript for the major LPA-producing enzyme autotaxin. The microarray results were validated for three highly relevant upregulated inflammatory transcripts using quantitative reverse transcription-polymerase chain reaction (QRT-PCR). Liquid chromatography-tandem mass spectrometry was used to assay time-dependent LPA species production by GFs. LPA 18:1 significantly regulated 20 GF novel and 27 known genes linked to the control of inflammation (P ≤0.01). QRT-PCR validation of interleukin (IL)-8, IL-11, and suppressor of cytokine signaling 2 (SOCS2) messenger RNAs confirmed statistically significant differences from control (P ≤0.05). Autotaxin transcript was present, and GFs were found to produce multiple LPA species in a time-dependent manner. The upregulation of transcripts for known GF proinflammatory (IL-6, IL-8) and anti-inflammatory (IL-11) ILs, along with SOCS2, shows that LPA transiently regulates a complex set of GF genes critical to periodontal wound healing and inflammation. These results implicate LPA exerting actions on GFs that are compatible with functioning as a mediator in oral fibroblast biology and inflammatory responses. Therefore, LPA may potentially modulate/regulate periodontal inflammation.

  17. Lysophosphatidic Acid Up-Regulates Hexokinase II and Glycolysis to Promote Proliferation of Ovarian Cancer Cells1

    Science.gov (United States)

    Mukherjee, Abir; Ma, Yibao; Yuan, Fang; Gong, Yongling; Fang, Zhenyu; Mohamed, Esraa M.; Berrios, Erika; Shao, Huanjie; Fang, Xianjun

    2015-01-01

    Lysophosphatidic acid (LPA), a blood-borne lipid mediator, is present in elevated concentrations in ascites of ovarian cancer patients and other malignant effusions. LPA is a potent mitogen in cancer cells. The mechanism linking LPA signal to cancer cell proliferation is not well understood. Little is known about whether LPA affects glucose metabolism to accommodate rapid proliferation of cancer cells. Here we describe that in ovarian cancer cells, LPA enhances glycolytic rate and lactate efflux. A real time PCR-based miniarray showed that hexokinase II (HK2) was the most dramatically induced glycolytic gene to promote glycolysis in LPA-treated cells. Analysis of the human HK2 gene promoter identified the sterol regulatory element-binding protein as the primary mediator of LPA-induced HK2 transcription. The effects of LPA on HK2 and glycolysis rely on LPA2, an LPA receptor subtype overexpressed in ovarian cancer and many other malignancies. We further examined the general role of growth factor-induced glycolysis in cell proliferation. Like LPA, epidermal growth factor (EGF) elicited robust glycolytic and proliferative responses in ovarian cancer cells. Insulin-like growth factor 1 (IGF-1) and insulin, however, potently stimulated cell proliferation but only modestly induced glycolysis. Consistent with their differential effects on glycolysis, LPA and EGF-dependent cell proliferation was highly sensitive to glycolytic inhibition while the growth-promoting effect of IGF-1 or insulin was more resistant. These results indicate that LPA- and EGF-induced cell proliferation selectively involves up-regulation of HK2 and glycolytic metabolism. The work is the first to implicate LPA signaling in promotion of glucose metabolism in cancer cells. PMID:26476080

  18. Biochemical correction of short-chain acyl-coenzyme A dehydrogenase deficiency after portal vein injection of rAAV8-SCAD.

    Science.gov (United States)

    Beattie, Stuart G; Goetzman, Eric; Conlon, Thomas; Germain, Sean; Walter, Glenn; Campbell-Thompson, Martha; Matern, Dietrich; Vockley, Jerry; Flotte, Terence R

    2008-06-01

    Recombinant adeno-associated viral vectors pseudotyped with serotype 5 and 8 capsids (AAV5 and AAV8) have been shown to be efficient gene transfer reagents for the liver. We have produced AAV5 and AAV8 vectors that express mouse short-chain acyl-CoA dehydrogenase (mSCAD) cDNA under the transcriptional control of the cytomegalovirus-chicken beta-actin hybrid promoter. We hypothesized that these vectors would produce sufficient hepatocyte transduction (after administration via the portal vein) and thus sufficient SCAD enzyme to correct the phenotype observed in the SCAD-deficient (BALB/cByJ) mouse, which includes elevated blood butyrylcarnitine and hepatic steatosis. Ten weeks after portal vein injection into 8-week-old mice, AAV8-treated livers contained acyl-CoA dehydrogenase activity (14.3 mU/mg) toward butyryl-CoA, compared with 7.6 mU/mg in mice that received phosphate-buffered saline. Immunohistochemistry showed expression of mSCAD within rAAV8-mSCAD-transduced hepatocytes, as seen by light microscopy. A significant reduction of circulating butyrylcarnitine was seen in AAV5-mSCAD- and AAV8-mSCAD-injected mice. Magnetic resonance spectroscopy of fasted mice demonstrated a significant reduction in relative lipid content within the livers of AAV8-mSCAD-treated mice. These results demonstrate biochemical correction of SCAD deficiency after AAV8-mediated SCAD gene delivery.

  19. The effect of short/branched chain acyl-coenzyme A dehydrogenase gene on triglyceride synthesis of bovine mammary epithelial cells

    Directory of Open Access Journals (Sweden)

    P. Jiang

    2018-03-01

    Full Text Available Short/branched chain acyl-CoA dehydrogenase (ACADSB is a member of the acyl-CoA dehydrogenase family of enzymes that catalyze the dehydrogenation of acyl-CoA derivatives in the metabolism of fatty acids. Our previous transcriptome analysis in dairy cattle showed that ACADSB was differentially expressed and was associated with milk fat metabolism. The aim of this study was to elucidate the background of this differential expression and to evaluate the role of ACADSB as a candidate for fat metabolism in dairy cattle. After analysis of ACADSB mRNA abundance by qRT-PCR and Western blot, overexpression and RNA interference (RNAi vectors of ACADSB gene were constructed and then transfected into bovine mammary epithelial cells (bMECs to examine the effects of ACADSB on milk fat synthesis. The results showed that the ACADSB was differentially expressed in mammary tissue of low and high milk fat dairy cattle. Overexpression of ACADSB gene could significantly increase the level of intracellular triglyceride (TG, while ACADSB gene knockdown could significantly reduce the TG synthesis in bMECs. This study suggested that the ACADSB was important in TG synthesis in bMECs, and it could be a candidate gene to regulate the metabolism of milk fat in dairy cattle.

  20. Depletion of Acyl-Coenzyme A-Binding Protein Affects Sphingolipid Synthesis and Causes Vesicle Accumulation and Membrane Defects in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Gaigg, B; Neergaard, T B; Schneiter, R

    2001-01-01

    Deletion of the yeast gene ACB1 encoding Acb1p, the yeast homologue of the acyl-CoA-binding protein (ACBP), resulted in a slower growing phenotype that adapted into a faster growing phenotype with a frequency >1:10(5). A conditional knockout strain (Y700pGAL1-ACB1) with the ACB1 gene under contro...

  1. Systematic Analysis of Gene Expression Alterations and Clinical Outcomes for Long-Chain Acyl-Coenzyme A Synthetase Family in Cancer.

    Directory of Open Access Journals (Sweden)

    Wei-Ching Chen

    Full Text Available Dysregulated lipid metabolism contributes to cancer progression. Our previous study indicates that long-chain fatty acyl-Co A synthetase (ACSL 3 is essential for lipid upregulation induced by endoplasmic reticulum stress. In this report, we aimed to identify the role of ACSL family in cancer with systematic analysis and in vitro experiment. We explored the ACSL expression using Oncomine database to determine the gene alteration during carcinogenesis and identified the association between ACSL expression and the survival of cancer patient using PrognoScan database. ACSL1 may play a potential oncogenic role in colorectal and breast cancer and play a potential tumor suppressor role in lung cancer. Co-expression analysis revealed that ACSL1 was coexpressed with MYBPH, PTPRE, PFKFB3, SOCS3 in colon cancer and with LRRFIP1, TSC22D1 in lung cancer. In accordance with PrognoScan analysis, downregulation of ACSL1 in colon and breast cancer cell line inhibited proliferation, migration, and anchorage-independent growth. In contrast, increase of oncogenic property was observed in lung cancer cell line by attenuating ACSL1. High ACSL3 expression predicted a better prognosis in ovarian cancer; in contrast, high ACSL3 predicted a worse prognosis in melanoma. ACSL3 was coexpressed with SNUPN, TRIP13, and SEMA5A in melanoma. High expression of ACSL4 predicted a worse prognosis in colorectal cancer, but predicted better prognosis in breast, brain and lung cancer. ACSL4 was coexpressed with SERPIN2, HNRNPCL1, ITIH2, PROCR, LRRFIP1. High expression of ACSL5 predicted good prognosis in breast, ovarian, and lung cancers. ACSL5 was coexpressed with TMEM140, TAPBPL, BIRC3, PTPRE, and SERPINB1. Low ACSL6 predicted a worse prognosis in acute myeloid leukemia. ACSL6 was coexpressed with SOX6 and DARC. Altogether, different members of ACSLs are implicated in diverse types of cancer development. ACSL-coexpressed molecules may be used to further investigate the role of ACSL family in individual type of cancers.

  2. Mutations in LACS2, a long-chain acyl-coenzyme A synthetase, enhance susceptibility to avirulent Pseudomonas syringae but confer resistance to Botrytis cinerea in Arabidopsis.

    Science.gov (United States)

    Tang, Dingzhong; Simonich, Michael T; Innes, Roger W

    2007-06-01

    We identified an Arabidopsis (Arabidopsis thaliana) mutant, sma4 (symptoms to multiple avr genotypes4), that displays severe disease symptoms when inoculated with avirulent strains of Pseudomonas syringae pv tomato, although bacterial growth is only moderately enhanced compared to wild-type plants. The sma4 mutant showed a normal susceptible phenotype to the biotrophic fungal pathogen Erysiphe cichoracearum. Significantly, the sma4 mutant was highly resistant to a necrotrophic fungal pathogen, Botrytis cinerea. Germination of B. cinerea spores on sma4 mutant leaves was inhibited, and penetration by those that did germinate was rare. The sma4 mutant also showed several pleiotropic phenotypes, including increased sensitivity to lower humidity and salt stress. Isolation of SMA4 by positional cloning revealed that it encodes LACS2, a member of the long-chain acyl-CoA synthetases. LACS2 has previously been shown to be involved in cutin biosynthesis. We therefore tested three additional cutin-defective mutants for resistance to B. cinerea: att1 (for aberrant induction of type three genes), bodyguard, and lacerata. All three displayed an enhanced resistance to B. cinerea. Our results indicate that plant cutin or cuticle structure may play a crucial role in tolerance to biotic and abiotic stress and in the pathogenesis of B. cinerea.

  3. Depletion of Acyl-Coenzyme A-Binding Protein Affects Sphingolipid Synthesis and Causes Vesicle Accumulation and Membrane Defects in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Gaigg, B; Neergaard, T B; Schneiter, R

    2001-01-01

    of the GAL1 promoter exhibited an altered acyl-CoA profile with a threefold increase in the relative content of C18:0-CoA, without affecting total acyl-CoA level as previously reported for an adapted acb1Delta strain. Depletion of Acb1p did not affect the general phospholipid pattern, the rate......-depleted strain contained increased levels of inositol-phosphoceramide and mannose-inositol-phosphoceramide and lysophospholipids. Acb1p-depleted cells accumulated 50- to 60-nm vesicles and autophagocytotic like bodies and showed strongly perturbed plasma membrane structures. The present results strongly suggest...

  4. Cancer cell expression of autotaxin controls bone metastasis formation in mouse through lysophosphatidic acid-dependent activation of osteoclasts.

    Directory of Open Access Journals (Sweden)

    Marion David

    2010-03-01

    Full Text Available Bone metastases are highly frequent complications of breast cancers. Current bone metastasis treatments using powerful anti-resorptive agents are only palliative indicating that factors independent of bone resorption control bone metastasis progression. Autotaxin (ATX/NPP2 is a secreted protein with both oncogenic and pro-metastatic properties. Through its lysosphospholipase D (lysoPLD activity, ATX controls the level of lysophosphatidic acid (LPA in the blood. Platelet-derived LPA promotes the progression of osteolytic bone metastases of breast cancer cells. We asked whether ATX was involved in the bone metastasis process. We characterized the role of ATX in osteolytic bone metastasis formation by using genetically modified breast cancer cells exploited on different osteolytic bone metastasis mouse models.Intravenous injection of human breast cancer MDA-B02 cells with forced expression of ATX (MDA-B02/ATX to immunodeficiency BALB/C nude mice enhanced osteolytic bone metastasis formation, as judged by increased bone loss, tumor burden, and a higher number of active osteoclasts at the metastatic site. Mouse breast cancer 4T1 cells induced the formation of osteolytic bone metastases after intracardiac injection in immunocompetent BALB/C mice. These cells expressed active ATX and silencing ATX expression inhibited the extent of osteolytic bone lesions and decreased the number of active osteoclasts at the bone metastatic site. In vitro, osteoclast differentiation was enhanced in presence of MDA-B02/ATX cell conditioned media or recombinant autotaxin that was blocked by the autotaxin inhibitor vpc8a202. In vitro, addition of LPA to active charcoal-treated serum restored the capacity of the serum to support RANK-L/MCSF-induced osteoclastogenesis.Expression of autotaxin by cancer cells controls osteolytic bone metastasis formation. This work demonstrates a new role for LPA as a factor that stimulates directly cancer growth and metastasis, and

  5. Autotaxin, a synthetic enzyme of lysophosphatidic acid (LPA, mediates the induction of nerve-injured neuropathic pain

    Directory of Open Access Journals (Sweden)

    Chun Jerold

    2008-02-01

    Full Text Available Abstract Recently, we reported that lysophosphatidic acid (LPA induces long-lasting mechanical allodynia and thermal hyperalgesia as well as demyelination and upregulation of pain-related proteins through one of its cognate receptors, LPA1. In addition, mice lacking the LPA1 receptor gene (lpa1-/- mice lost these nerve injury-induced neuropathic pain behaviors and phenomena. However, since lpa1-/- mice did not exhibit any effects on the basal nociceptive threshold, it is possible that nerve injury-induced neuropathic pain and its machineries are initiated by LPA via defined biosynthetic pathways that involve multiple enzymes. Here, we attempted to clarify the involvement of a single synthetic enzyme of LPA known as autotaxin (ATX in nerve injury-induced neuropathic pain. Wild-type mice with partial sciatic nerve injury showed robust mechanical allodynia starting from day 3 after the nerve injury and persisting for at least 14 days, along with thermal hyperalgesia. On the other hand, heterozygous mutant mice for the autotaxin gene (atx+/-, which have 50% ATX protein and 50% lysophospholipase D activity compared with wild-type mice, showed approximately 50% recovery of nerve injury-induced neuropathic pain. In addition, hypersensitization of myelinated Aβ˜ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGacaGaaiaabeqaaeqabiWaaaGcbaGafqOSdiMbaGaaaaa@2D83@- or Aδ-fiber function following nerve injury was observed in electrical stimuli-induced paw withdrawal tests using a Neurometer®. The hyperalgesia was completely abolished in lpa1-/- mice, and reduced by 50% in atx+/- mice. Taken together, these findings suggest that LPA biosynthesis through ATX is the source of LPA for LPA1 receptor-mediated neuropathic pain. Therefore, targeted inhibition of ATX-mediated LPA biosynthesis as well as

  6. Derivatives of Dictyostelium differentiation-inducing factors inhibit lysophosphatidic acid–stimulated migration of murine osteosarcoma LM8 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kubohara, Yuzuru, E-mail: ykuboha@juntendo.ac.jp [Department of Molecular and Cellular Biology, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512 (Japan); Department of Health Science, Juntendo University Graduate School of Health and Sports Science, Inzai 270-1695 (Japan); Komachi, Mayumi [Department of Molecular and Cellular Biology, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512 (Japan); Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi 371-8511 (Japan); Homma, Yoshimi [Department of Biomolecular Science, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295 (Japan); Kikuchi, Haruhisa; Oshima, Yoshiteru [Laboratory of Natural Product Chemistry, Tohoku University Graduate School of Pharmaceutical Sciences, Aoba-yama, Aoba-ku, Sendai 980-8578 (Japan)

    2015-08-07

    Osteosarcoma is a common metastatic bone cancer that predominantly develops in children and adolescents. Metastatic osteosarcoma remains associated with a poor prognosis; therefore, more effective anti-metastatic drugs are needed. Differentiation-inducing factor-1 (DIF-1), −2, and −3 are novel lead anti-tumor agents that were originally isolated from the cellular slime mold Dictyostelium discoideum. Here we investigated the effects of a panel of DIF derivatives on lysophosphatidic acid (LPA)-induced migration of mouse osteosarcoma LM8 cells by using a Boyden chamber assay. Some DIF derivatives such as Br-DIF-1, DIF-3(+2), and Bu-DIF-3 (5–20 μM) dose-dependently suppressed LPA-induced cell migration with associated IC{sub 50} values of 5.5, 4.6, and 4.2 μM, respectively. On the other hand, the IC{sub 50} values of Br-DIF-1, DIF-3(+2), and Bu-DIF-3 versus cell proliferation were 18.5, 7.2, and 2.0 μM, respectively, in LM8 cells, and >20, 14.8, and 4.3 μM, respectively, in mouse 3T3-L1 fibroblasts (non-transformed). Together, our results demonstrate that Br-DIF-1 in particular may be a valuable tool for the analysis of cancer cell migration, and that DIF derivatives such as DIF-3(+2) and Bu-DIF-3 are promising lead anti-tumor agents for the development of therapies that suppress osteosarcoma cell proliferation, migration, and metastasis. - Highlights: • LPA induces cell migration (invasion) in murine osteosarcoma LM8 cells. • DIFs are novel lead anti-tumor agents found in Dictyostelium discoideum. • We examined the effects of DIF derivatives on LPA-induced LM8 cell migration in vitro. • Some of the DIF derivatives inhibited LPA-induced LM8 cell migration.

  7. Derivatives of Dictyostelium differentiation-inducing factors inhibit lysophosphatidic acid–stimulated migration of murine osteosarcoma LM8 cells

    International Nuclear Information System (INIS)

    Kubohara, Yuzuru; Komachi, Mayumi; Homma, Yoshimi; Kikuchi, Haruhisa; Oshima, Yoshiteru

    2015-01-01

    Osteosarcoma is a common metastatic bone cancer that predominantly develops in children and adolescents. Metastatic osteosarcoma remains associated with a poor prognosis; therefore, more effective anti-metastatic drugs are needed. Differentiation-inducing factor-1 (DIF-1), −2, and −3 are novel lead anti-tumor agents that were originally isolated from the cellular slime mold Dictyostelium discoideum. Here we investigated the effects of a panel of DIF derivatives on lysophosphatidic acid (LPA)-induced migration of mouse osteosarcoma LM8 cells by using a Boyden chamber assay. Some DIF derivatives such as Br-DIF-1, DIF-3(+2), and Bu-DIF-3 (5–20 μM) dose-dependently suppressed LPA-induced cell migration with associated IC 50 values of 5.5, 4.6, and 4.2 μM, respectively. On the other hand, the IC 50 values of Br-DIF-1, DIF-3(+2), and Bu-DIF-3 versus cell proliferation were 18.5, 7.2, and 2.0 μM, respectively, in LM8 cells, and >20, 14.8, and 4.3 μM, respectively, in mouse 3T3-L1 fibroblasts (non-transformed). Together, our results demonstrate that Br-DIF-1 in particular may be a valuable tool for the analysis of cancer cell migration, and that DIF derivatives such as DIF-3(+2) and Bu-DIF-3 are promising lead anti-tumor agents for the development of therapies that suppress osteosarcoma cell proliferation, migration, and metastasis. - Highlights: • LPA induces cell migration (invasion) in murine osteosarcoma LM8 cells. • DIFs are novel lead anti-tumor agents found in Dictyostelium discoideum. • We examined the effects of DIF derivatives on LPA-induced LM8 cell migration in vitro. • Some of the DIF derivatives inhibited LPA-induced LM8 cell migration

  8. Lysophosphatidic acid signaling via LPA1 and LPA3 regulates cellular functions during tumor progression in pancreatic cancer cells

    International Nuclear Information System (INIS)

    Fukushima, Kaori; Takahashi, Kaede; Yamasaki, Eri; Onishi, Yuka; Fukushima, Nobuyuki; Honoki, Kanya; Tsujiuchi, Toshifumi

    2017-01-01

    Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors exhibits a variety of biological effects, such as cell proliferation, motility and differentiation. The aim of this study was to evaluate the roles of LPA 1 and LPA 3 in cellular functions during tumor progression in pancreatic cancer cells. LPA 1 and LPA 3 knockdown cells were generated from PANC-1 cells. The cell motile and invasive activities of PANC-1 cells were inhibited by LPA 1 and LPA 3 knockdown. In gelatin zymography, LPA 1 and LPA 3 knockdown cells indicated the low activation of matrix metalloproteinase-2 (MMP-2) in the presence of LPA. Next, to assess whether LPA 1 and LPA 3 regulate cellular functions induced by anticancer drug, PANC-1 cells were treated with cisplatin (CDDP) for approximately 6 months. The cell motile and invasive activities of long-term CDDP treated cells were markedly higher than those of PANC-1 cells, correlating with the expression levels of LPAR1 and LPAR3 genes. In soft agar assay, the long-term CDDP treated cells formed markedly large sized colonies. In addition, the cell motile and invasive activities enhanced by CDDP were significantly suppressed by LPA 1 and LPA 3 knockdown as well as colony formation. These results suggest that LPA signaling via LPA 1 and LPA 3 play an important role in the regulation of cellular functions during tumor progression in PANC-1 cells. - Highlights: • The cell motile and invasive activities of PANC-1 cells were stimulated by LPA 1 and LPA 3 . • LPA 1 and LPA 3 enhanced MMP-2 activation in PANC-1 cells. • The expressions of LPAR1 and LPAR3 genes were elevated in PANC-1 cells treated with cisplatin. • The cell motile and invasive activities of PANC-1 cells treated with cisplatin were suppressed by LPA 1 and LPA 3 knockdown. • LPA 1 and LPA 3 are involved in the regulation of cellular functions during tumor progression in PANC-1 cells.

  9. Gene regulatory networking reveals the molecular cue to lysophosphatidic acid-induced metabolic adaptations in ovarian cancer cells.

    Science.gov (United States)

    Ray, Upasana; Roy Chowdhury, Shreya; Vasudevan, Madavan; Bankar, Kiran; Roychoudhury, Susanta; Roy, Sib Sankar

    2017-05-01

    Extravasation and metastatic progression are two main reasons for the high mortality rate associated with cancer. The metastatic potential of cancer cells depends on a plethora of metabolic challenges prevailing within the tumor microenvironment. To achieve higher rates of proliferation, cancer cells reprogram their metabolism, increasing glycolysis and biosynthetic activities. Just why this metabolic reprogramming predisposes cells towards increased oncogenesis remains elusive. The accumulation of myriad oncolipids in the tumor microenvironment has been shown to promote the invasiveness of cancer cells, with lysophosphatidic acid (LPA) being one such critical factor enriched in ovarian cancer patients. Cellular bioenergetic studies confirm that oxidative phosphorylation is suppressed and glycolysis is increased with long exposure to LPA in ovarian cancer cells compared with non-transformed epithelial cells. We sought to uncover the regulatory complexity underlying this oncolipid-induced metabolic perturbation. Gene regulatory networking using RNA-Seq analysis identified the oncogene ETS-1 as a critical mediator of LPA-induced metabolic alterations for the maintenance of invasive phenotype. Moreover, LPA receptor-2 specific PtdIns3K-AKT signaling induces ETS-1 and its target matrix metalloproteases. Abrogation of ETS-1 restores cellular bioenergetics towards increased oxidative phosphorylation and reduced glycolysis, and this effect was reversed by the presence of LPA. Furthermore, the bioenergetic status of LPA-treated ovarian cancer cells mimics hypoxia through induction of hypoxia-inducible factor-1α, which was found to transactivate ets-1. Studies in primary tumors generated in syngeneic mice corroborated the in vitro findings. Thus, our study highlights the phenotypic changes induced by the pro-metastatic factor ETS-1 in ovarian cancer cells. The relationship between enhanced invasiveness and metabolic plasticity further illustrates the critical role of

  10. Lysophosphatidic acid activates peroxisome proliferator activated receptor-γ in CHO cells that over-express glycerol 3-phosphate acyltransferase-1.

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    Cliona M Stapleton

    Full Text Available Lysophosphatidic acid (LPA is an agonist for peroxisome proliferator activated receptor-γ (PPARγ. Although glycerol-3-phosphate acyltransferase-1 (GPAT1 esterifies glycerol-3-phosphate to form LPA, an intermediate in the de novo synthesis of glycerolipids, it has been assumed that LPA synthesized by this route does not have a signaling role. The availability of Chinese Hamster Ovary (CHO cells that stably overexpress GPAT1, allowed us to analyze PPARγ activation in the presence of LPA produced as an intracellular intermediate. LPA levels in CHO-GPAT1 cells were 6-fold higher than in wild-type CHO cells, and the mRNA abundance of CD36, a PPARγ target, was 2-fold higher. Transactivation assays showed that PPARγ activity was higher in the cells that overexpressed GPAT1. PPARγ activity was enhanced further in CHO-GPAT1 cells treated with the PPARγ ligand troglitazone. Extracellular LPA, phosphatidic acid (PA or a membrane-permeable diacylglycerol had no effect, showing that PPARγ had been activated by LPA generated intracellularly. Transient transfection of a vector expressing 1-acylglycerol-3-phosphate acyltransferase-2, which converts endogenous LPA to PA, markedly reduced PPARγ activity, as did over-expressing diacylglycerol kinase, which converts DAG to PA, indicating that PA could be a potent inhibitor of PPARγ. These data suggest that LPA synthesized via the glycerol-3-phosphate pathway can activate PPARγ and that intermediates of de novo glycerolipid synthesis regulate gene expression.

  11. Mechanism of sphingosine 1-phosphate- and lysophosphatidic Acid-induced up-regulation of adhesion molecules and eosinophil chemoattractant in nerve cells.

    LENUS (Irish Health Repository)

    Costello, Richard W

    2011-05-01

    The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) act via G-protein coupled receptors S1P(1-5) and LPA(1-3) respectively, and are implicated in allergy. Eosinophils accumulate at innervating cholinergic nerves in asthma and adhere to nerve cells via intercellular adhesion molecule-1 (ICAM-1). IMR-32 neuroblastoma cells were used as an in vitro cholinergic nerve cell model. The G(i) coupled receptors S1P(1), S1P(3), LPA(1), LPA(2) and LPA(3) were expressed on IMR-32 cells. Both S1P and LPA induced ERK phosphorylation and ERK- and G(i)-dependent up-regulation of ICAM-1 expression, with differing time courses. LPA also induced ERK- and G(i)-dependent up-regulation of the eosinophil chemoattractant, CCL-26. The eosinophil granule protein eosinophil peroxidase (EPO) induced ERK-dependent up-regulation of transcription of S1P(1), LPA(1), LPA(2) and LPA(3), providing the situation whereby eosinophil granule proteins may enhance S1P- and\\/or LPA- induced eosinophil accumulation at nerve cells in allergic conditions.

  12. Mechanism of sphingosine 1-phosphate- and lysophosphatidic Acid-induced up-regulation of adhesion molecules and eosinophil chemoattractant in nerve cells.

    LENUS (Irish Health Repository)

    Costello, Richard W

    2012-02-01

    The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) act via G-protein coupled receptors S1P(1-5) and LPA(1-3) respectively, and are implicated in allergy. Eosinophils accumulate at innervating cholinergic nerves in asthma and adhere to nerve cells via intercellular adhesion molecule-1 (ICAM-1). IMR-32 neuroblastoma cells were used as an in vitro cholinergic nerve cell model. The G(i) coupled receptors S1P(1), S1P(3), LPA(1), LPA(2) and LPA(3) were expressed on IMR-32 cells. Both S1P and LPA induced ERK phosphorylation and ERK- and G(i)-dependent up-regulation of ICAM-1 expression, with differing time courses. LPA also induced ERK- and G(i)-dependent up-regulation of the eosinophil chemoattractant, CCL-26. The eosinophil granule protein eosinophil peroxidase (EPO) induced ERK-dependent up-regulation of transcription of S1P(1), LPA(1), LPA(2) and LPA(3), providing the situation whereby eosinophil granule proteins may enhance S1P- and\\/or LPA- induced eosinophil accumulation at nerve cells in allergic conditions.

  13. Enhanced root growth in phosphate-starved Arabidopsis by stimulating de novo phospholipid biosynthesis through the overexpression of LYSOPHOSPHATIDIC ACID ACYLTRANSFERASE 2 (LPAT2).

    Science.gov (United States)

    Angkawijaya, Artik Elisa; Nguyen, Van Cam; Nakamura, Yuki

    2017-09-01

    Upon phosphate starvation, plants retard shoot growth but promote root development presumably to enhance phosphate assimilation from the ground. Membrane lipid remodelling is a metabolic adaptation that replaces membrane phospholipids by non-phosphorous galactolipids, thereby allowing plants to obtain scarce phosphate yet maintain the membrane structure. However, stoichiometry of this phospholipid-to-galactolipid conversion may not account for the massive demand of membrane lipids that enables active growth of roots under phosphate starvation, thereby suggesting the involvement of de novo phospholipid biosynthesis, which is not represented in the current model. We overexpressed an endoplasmic reticulum-localized lysophosphatidic acid acyltransferase, LPAT2, a key enzyme that catalyses the last step of de novo phospholipid biosynthesis. Two independent LPAT2 overexpression lines showed no visible phenotype under normal conditions but showed increased root length under phosphate starvation, with no effect on phosphate starvation response including marker gene expression, root hair development and anthocyanin accumulation. Accompanying membrane glycerolipid profiling of LPAT2-overexpressing plants revealed an increased content of major phospholipid classes and distinct responses to phosphate starvation between shoot and root. The findings propose a revised model of membrane lipid remodelling, in which de novo phospholipid biosynthesis mediated by LPAT2 contributes significantly to root development under phosphate starvation. © 2017 John Wiley & Sons Ltd.

  14. Quantitative Phosphoproteome Analysis of Lysophosphatidic Acid Induced Chemotaxis applying Dual-step ¹⁸O Labeling Coupled with Immobilized Metal-ion Affinity Chromatography

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    Ding, Shi-Jian; Wang, Yingchun; Jacobs, Jon M.; Qian, Weijun; Yang, Feng; Tolmachev, Aleksey V.; Du, Xiuxia; Wang, Wei; Moore, Ronald J.; Monroe, Matthew E.; Purvine, Samuel O.; Waters, Katrina M.; Heibeck, Tyler H.; Adkins, Joshua N.; Camp, David G.; Klemke, Richard L.; Smith, Richard D.

    2008-10-01

    Reversible protein phosphorylation is a central cellular regulatory mechanism in modulating protein activity and propagating signals within cellular pathways and networks. Development of more effective methods for the simultaneous identification of phosphorylation sites and quantification of temporal changes in protein phosphorylation could provide important insights into molecular signaling mechanisms in a variety of different cellular processes. Here we present an integrated quantitative phosphoproteomics approach and its applications for comparative analysis of Cos-7 cells in response to lysophosphatidic acid (LPA) gradient stimulation. The approach combines trypsin-catalyzed 16O/18O labeling plus 16O/18O-methanol esterification labeling for quantitation, a macro- Immobilized Metal-ion Affinity Chromatography trap for phosphopeptide enrichment, and a monolithic capillary column with integrated electrospray emitter. LC separation and MS/MS is followed by neutral loss-dependent MS/MS/MS for phosphopeptide identification using a linear ion trap (LTQ)-FT mass spectrometer and complementary searching algorithms for interpreting MS/MS spectra. Protein phosphorylation involved in various signaling pathways of cell migration were identified and quantified, such as mitogen-activated protein kinase 1, dual-specificity mitogen-activated protein kinase kinase 2, and dual-specificity tyrosine-phosphorylation regulated kinase 1b, and a number of Rho GTPase-activating proteins. These results demonstrate the efficiency of this quantitative phosphoproteomics approach and its application for rapid discovery of phosphorylation events associated with gradient sensing and cell chemotaxis.

  15. Heart-type fatty-acid-binding protein (FABP3 is a lysophosphatidic acid-binding protein in human coronary artery endothelial cells

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    Ryoko Tsukahara

    2014-01-01

    Full Text Available Fatty-acid-binding protein 3, muscle and heart (FABP3, also known as heart-type FABP, is a member of the family of intracellular lipid-binding proteins. It is a small cytoplasmic protein with a molecular mass of about 15 kDa. FABPs are known to be carrier proteins for transporting fatty acids and other lipophilic substances from the cytoplasm to the nucleus, where these lipids are released to a group of nuclear receptors such as peroxisome proliferator-activated receptors (PPARs. In this study, using lysophosphatidic acid (LPA-coated agarose beads, we have identified FABP3 as an LPA carrier protein in human coronary artery endothelial cells (HCAECs. Administration of LPA to HCAECs resulted in a dose-dependent increase in PPARγ activation. Furthermore, the LPA-induced PPARγ activation was abolished when the FABP3 expression was reduced using small interfering RNA (siRNA. We further show that the nuclear fraction of control HCAECs contained a significant amount of exogenously added LPA, whereas FABP3 siRNA-transfected HCAECs had a decreased level of LPA in the nucleus. Taken together, these results suggest that FABP3 governs the transcriptional activities of LPA by targeting them to cognate PPARγ in the nucleus.

  16. Lysophosphatidic Acid Up-regulates MT1-MMP Expression through a Gi –dependent Pathway in Human Umbilical Vein Endothelial Cells

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    Po-Wei Lin

    2009-11-01

    Full Text Available Lysophosphatidic acid (LPA is a low molecular weight lysophospholipid (LPL. Through binding to its specific G protein-coupled receptor family, LPA regulates various cellular functions, including proliferation, migration, invasion, and differentiation. Matrix-metalloproteinases (MMPs are zinc-dependent protease and play important roles in regulating the interaction between cells and extracellular matrix (ECM. Among these MMPs, membrane type 1-metalloproteinase (MT1-MMP not only degrades ECM protein but also activates metalloproteinase-2 (MMP-2, Gelatinase A, which are important to endothelial cell migration. Our previous study showed that LPA enhances MMP-2 expression and activity in human umbilical vein endothelial cells (HUVECs. In this study, we further revealed that LPA also induce MT1-MMP mRNA and protein expressions in HUVECs through real-time PCR and Western blotting, respectively. Furthermore, by applying chemical inhibitors, we found that LPA-induced MT1-MMP expression is mainly through a Gi- and partially through a Gq-dependent pathway. Our results provide new evidence that LPA might modulate ECM through regulating the expression of MT1-MMP.

  17. Lysophosphatidic Acid Is Associated with Atherosclerotic Plaque Instability by Regulating NF-κB Dependent Matrix Metalloproteinase-9 Expression via LPA2 in Macrophages

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    Xi Chen

    2017-04-01

    Full Text Available Lysophosphatidic acid (LPA, one of the simplest phospholipid signaling molecules, participates in formation and disruption of atherosclerotic plaque. Matrix metalloproteinases (MMPs contribute to atherosclerotic plaque rupture by involving in extracellular matrix (ECM degradation and then thinning fibrous cap. Our previous study demonstrated that macrophage-derived MMP-9 was associated with coronary plaque instability, but the relationship between LPA and MMP-9 remains unclear. The present work therefore aimed at elucidating association between LPA and MMP-9 and the regulation mechanism of LPA on MMP-9 in macrophages. We found that plasma LPA and MMP-9 levels were correlated positively (r = 0.31, P < 0.05 and both elevated significantly in patients with acute myocardial infarct (AMI. Consistent with peripheral blood levels, histochemical staining indicated that autotaxin (ATX, LPA-producing ectoenzyme, and MMP-9 were expressed frequently in the necrotic core and fibrous cap of human unstable plaques, which might increase the instability of plaque. Experiments in vitro were done with THP-1-derived macrophages and showed that LPA enhanced the expression, secretion and activity of MMP-9 in a time- and dose-dependent manner. Induction of LPA on pro-MMP-9 and active-MMP-9 was confirmed in human peripheral blood monocyte-derived macrophages. PDTC, NF-κB inhibitor, but not inhibitor of AP-1 and PPARγ, effectively prevented LPA-induced MMP-9 expression and NF-κB p65 siRNA decreased MMP-9 transcription, confirming that LPA might induce MMP-9 elevation by activating NF-κB pathway. In addition, knockdown of LPA2 attenuated LPA-induced MMP-9 expression and nucleus p65 levels. These findings revealed that LPA upregulated the expression of MMP-9 through activating NF-κB pathway in the LPA2 dependent manner, hence blocking LPA receptors signaling may provide therapeutic strategy to target plaque destabilization.

  18. Lysophosphatidic acid receptor mRNA levels in heart and white adipose tissue are associated with obesity in mice and humans.

    Directory of Open Access Journals (Sweden)

    Amy Brown

    Full Text Available Lysophosphatidic acid (LPA receptor signaling has been implicated in cardiovascular and obesity-related metabolic disease. However, the distribution and regulation of LPA receptors in the myocardium and adipose tissue remain unclear.This study aimed to characterize the mRNA expression of LPA receptors (LPA1-6 in the murine and human myocardium and adipose tissue, and its regulation in response to obesity.LPA receptor mRNA levels were determined by qPCR in i heart ventricles, isolated cardiomyocytes, and perigonadal adipose tissue from chow or high fat-high sucrose (HFHS-fed male C57BL/6 mice, ii 3T3-L1 adipocytes and HL-1 cardiomyocytes under conditions mimicking gluco/lipotoxicity, and iii human atrial and subcutaneous adipose tissue from non-obese, pre-obese, and obese cardiac surgery patients.LPA1-6 were expressed in myocardium and white adipose tissue from mice and humans, except for LPA3, which was undetectable in murine adipocytes and human adipose tissue. Obesity was associated with increased LPA4, LPA5 and/or LPA6 levels in mice ventricles and cardiomyocytes, HL-1 cells exposed to high palmitate, and human atrial tissue. LPA4 and LPA5 mRNA levels in human atrial tissue correlated with measures of obesity. LPA5 mRNA levels were increased in HFHS-fed mice and insulin resistant adipocytes, yet were reduced in adipose tissue from obese patients. LPA4, LPA5, and LPA6 mRNA levels in human adipose tissue were negatively associated with measures of obesity and cardiac surgery outcomes. This study suggests that obesity leads to marked changes in LPA receptor expression in the murine and human heart and white adipose tissue that may alter LPA receptor signaling during obesity.

  19. Lysophosphatidic acid modulates the association of PTP1B with N-cadherin/catenin complex in SKOV3 ovarian cancer cells.

    Science.gov (United States)

    Huang, Ruby Yun-Ju; Wen, Chen-Chen; Liao, Chih-Kai; Wang, Shu-Huei; Chou, Liang-Yin; Wu, Jiahn-Chun

    2012-09-01

    LPA (lysophosphatidic acid) is a natural phospholipid that plays important roles in promoting cancer cell proliferation, invasion and metastases. We previously reported that LPA induces ovarian cancer cell dispersal and disruption of AJ (adherens junction) through the activation of SFK (Src family kinases). In this study, we have investigated the regulatory mechanisms during the early phase of LPA-induced cell dispersal. An in vitro model of the ovarian cancer cell line SKOV3 for cell dispersal was used. LPA induces rapid AJ disruption by increasing the internalization of N-cadherin-β-catenin. By using immunoprecipitations, LPA was shown to induce increased tyrosine phosphorylation of β-catenin and alter the balance of β-catenin-bound SFK and PTP1B (phosphotyrosine phosphatase 1B). The altered balance of tyrosine kinase/phosphatase correlated with a concomitant disintegration of the β-catenin-α-catenin, but not the β-catenin-N-cadherin complex. This disintegration of β-catenin from α-catenin and the cell dispersal caused by LPA can be rescued by blocking SFK activity with the chemical inhibitor, PP2. More importantly, PP2 also restores the level of PTP1B bound to β-catenin. We propose that LPA signalling alters AJ stability by changing the dynamics of tyrosine kinase/phosphatase bound to AJ proteins. This work provides further understanding of the early signalling events regulating ovarian cancer cell dispersal and AJ disruption induced by LPA. © The Author(s) Journal compilation © 2012 International Federation for Cell Biology.

  20. Analysis of lysophosphatidic acid (LPA) receptor and LPA-induced endometrial prostaglandin-endoperoxide synthase 2 expression in the porcine uterus.

    Science.gov (United States)

    Seo, Heewon; Kim, Mingoo; Choi, Yohan; Lee, Chang-Kyu; Ka, Hakhyun

    2008-12-01

    Lysophosphatidic acid (LPA), a simple phospholipid-derived mediator with diverse biological actions, acts through the specific G protein-coupled receptors endothelial differentiation gene (EDG) 2, EDG4, EDG7, and GPR23. Recent studies indicate a critical role for LPA receptor signaling in embryo implantation. To understand how LPA acts in the uterus during pregnancy in pigs, we evaluated: 1) spatial and temporal expression of LPA receptors in the uterine endometrium during the estrous cycle and pregnancy and in early-stage concepti, 2) LPA levels in uterine luminal fluids from d 12 of the estrous cycle and pregnancy, 3) effects of steroid hormones on EDG7 mRNA levels, and 4) effects of LPA on prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA levels in the uterine endometrium using explant cultures. Of the four receptors, EDG7 was dominant, and its expression was regulated by pregnancy stage and status. EDG7 expression was highest on d 12 pregnancy, and localized to the luminal and glandular epithelium, and EDG7 mRNA levels were elevated by estrogen in the endometrium. EDG7 expression was also detected in concepti of d 12 and 15. LPA with various fatty acyl groups was present in the uterine lumen on d 12 of both the estrous cycle and pregnancy. LPA increased PTGS2 mRNA abundance in the uterine endometrium. These results indicate that LPA produced in the uterine endometrium may play a critical role in uterine endometrial function and conceptus development through EDG7-mediated PTGS2 expression during implantation and establishment of pregnancy in pigs.

  1. Three lysophosphatidic acids with a distinct long chain moiety differently affect cell differentiation of human colon epithelial cells to goblet cells.

    Science.gov (United States)

    Hidaka, Mayumi; Nishihara, Mai; Tokumura, Akira

    2018-03-15

    The intestinal mucus layer helps maintain intestinal homeostasis. In this study, we investigated the effects of lysophosphatidic acids (LPA) on differentiation of human colon carcinoma cell line, HT-29, to goblet cells with and without sodium butyrate, a known differentiation factor for intestinal cells. Number and average size of cells with goblet-like morphology in five photographs per dish were measured for assessment of differentiation of HT-29 cells to goblet cells as well as their relative portion of surface of to whole surface area of the photograph. Our results revealed that 18:1 LPA enhanced butyrate-induced differentiation of HT-29 cells. Because increased mRNA expression of LPA 5 and decreased mRNA expression of LPA 6 were observed in HT-29 cells after treatment with butyrate, we explored the effects of alkyl LPA and 20:4 LPA, which show preferentially higher affinities to LPA 5 and LPA 6 , respectively. As a result, the cell differentiation to goblet cell was increased by alkyl LPA but decreased by 20:4 LPA. Further, alkyl LPA and 18:1 LPA, but not 20:4 LPA, were found to reduce the numbers of cells surviving after incubation in a standard culture medium containing 10% fetal calf serum. We suggest that the three LPAs positively and negatively affect the differentiation of HT-29 cells to goblet cells, which may be associated with their reduced survival through the activation of distinct LPA receptor(s). Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Lysophosphatidic acid signaling through its receptor initiates profibrotic epithelial cell fibroblast communication mediated by epithelial cell derived connective tissue growth factor.

    Science.gov (United States)

    Sakai, Norihiko; Chun, Jerold; Duffield, Jeremy S; Lagares, David; Wada, Takashi; Luster, Andrew D; Tager, Andrew M

    2017-03-01

    The expansion of the fibroblast pool is a critical step in organ fibrosis, but the mechanisms driving expansion remain to be fully clarified. We previously showed that lysophosphatidic acid (LPA) signaling through its receptor LPA 1 expressed on fibroblasts directly induces the recruitment of these cells. Here we tested whether LPA-LPA 1 signaling drives fibroblast proliferation and activation during the development of renal fibrosis. LPA 1 -deficient (LPA 1 -/- ) or -sufficient (LPA 1 +/+ ) mice were crossed to mice with green fluorescent protein expression (GFP) driven by the type I procollagen promoter (Col-GFP) to identify fibroblasts. Unilateral ureteral obstruction-induced increases in renal collagen were significantly, though not completely, attenuated in LPA 1 -/- Col-GFP mice, as were the accumulations of both fibroblasts and myofibroblasts. Connective tissue growth factor was detected mainly in tubular epithelial cells, and its levels were suppressed in LPA 1 -/- Col-GFP mice. LPA-LPA 1 signaling directly induced connective tissue growth factor expression in primary proximal tubular epithelial cells, through a myocardin-related transcription factor-serum response factor pathway. Proximal tubular epithelial cell-derived connective tissue growth factor mediated renal fibroblast proliferation and myofibroblast differentiation. Administration of an inhibitor of myocardin-related transcription factor/serum response factor suppressed obstruction-induced renal fibrosis. Thus, targeting LPA-LPA 1 signaling and/or myocardin-related transcription factor/serum response factor-induced transcription could be promising therapeutic strategies for renal fibrosis. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  3. Endosomal H2O2 production leads to localized cysteine sulfenic acid formation on proteins during lysophosphatidic acid-mediated cell signaling.

    Science.gov (United States)

    Klomsiri, Chananat; Rogers, LeAnn C; Soito, Laura; McCauley, Anita K; King, S Bruce; Nelson, Kimberly J; Poole, Leslie B; Daniel, Larry W

    2014-06-01

    Lysophosphatidic acid (LPA) is a growth factor for many cells including prostate and ovarian cancer-derived cell lines. LPA stimulates H2O2 production which is required for growth. However, there are significant gaps in our understanding of the spatial and temporal regulation of H2O2-dependent signaling and the way in which signals are transmitted following receptor activation. Herein, we describe the use of two reagents, DCP-Bio1 and DCP-Rho1, to evaluate the localization of active protein oxidation after LPA stimulation by detection of nascent protein sulfenic acids. We found that LPA stimulation causes internalization of LPA receptors into early endosomes that contain NADPH oxidase components and are sites of H2O2 generation. DCP-Rho1 allowed visualization of sulfenic acid formation, indicative of active protein oxidation, which was stimulated by LPA and decreased by an LPA receptor antagonist. Protein oxidation sites colocalized with LPAR1 and the endosomal marker EEA1. Concurrent with the generation of these redox signaling-active endosomes (redoxosomes) is the H2O2- and NADPH oxidase-dependent oxidation of Akt2 and PTP1B detected using DCP-Bio1. These new approaches therefore enable detection of active, H2O2-dependent protein oxidation linked to cell signaling processes. DCP-Rho1 may be a particularly useful protein oxidation imaging agent enabling spatial resolution due to the transient nature of the sulfenic acid intermediate it detects. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Enhancement of Human Endothelial Cell Adhesion to Type I Collagen by Lysophosphatidic Acid (LPA and Sphingosine-1-Phosphate (S1P

    Directory of Open Access Journals (Sweden)

    Hsinyu Lee

    2004-06-01

    Full Text Available The diverse cellular effects of lysophosphatidic acid (LPA and sphingosine-1-phosphate (S1P are transduced by two structurally homologous subfamilies of G protein-coupled receptors, which are encoded by endothelial differentiation genes (Edg Rs. Human umbilical cord vein endothelial cells (HUVECs express Edg Rs for LPA (Edg2 and S1P (Edg1 and 3, which transduce signals for migration of HUVECs through micropore filters coated with type I collagen. Since activation of integrins is essential for optimal migration of endothelial cells, we now examine the capacity of LPA and S1P to augment integrin mediation of endothelial cell binding to type I collagen. Lysophospholipid enhancement of HUVEC adhesion to type I collagen is detectable within 20 minutes. Enhancement of adhesion by both LPA and S1P is significant at 50 nM and optimal at 5µM. Pertussis toxin (PTx, a specific inhibitor of Gi, and C3 exotoxin, a specific inhibitor of Rho, both suppress LPA and S1P enhancement of HUVEC adhesion. In contrast, PD98059, which blocks MAP kinase kinase (MEK, and wortmannin, which inhibits phosphatidylinositol 3-kinase (PI3K, had no effect on LPA- or S1P-enhancement of HUVEC adhesion. Neutralizing monoclonal antibodies specific for α2 and β1 integrin chains, concomitantly decrease LPA and S1P enhancement of HUVEC adhesion to type I collagen. LPA and S1P thus promote type I collagen-dependent adhesion and migration of HUVECs by recruiting α2 and β1 integrin through both Gi and Rho pathways. Integrin α2/β1 therefore appears to be critical on the effects of LPA and S1P on endothelial cell physiology.

  5. β-Arrestin2 regulates lysophosphatidic acid-induced human breast tumor cell migration and invasion via Rap1 and IQGAP1.

    Directory of Open Access Journals (Sweden)

    Mistre Alemayehu

    Full Text Available β-Arrestins play critical roles in chemotaxis and cytoskeletal reorganization downstream of several receptor types, including G protein-coupled receptors (GPCRs, which are targets for greater than 50% of all pharmaceuticals. Among them, receptors for lysophosphatidic acid (LPA, namely LPA(1 are overexpressed in breast cancer and promote metastatic spread. We have recently reported that β-arrestin2 regulates LPA(1-mediated breast cancer cell migration and invasion, although the underlying molecular mechanisms are not clearly understood. We show here that LPA induces activity of the small G protein, Rap1 in breast cancer cells in a β-arrestin2-dependent manner, but fails to activate Rap1 in non-malignant mammary epithelial cells. We found that Rap1A mRNA levels are higher in human breast tumors compared to healthy patient samples and Rap1A is robustly expressed in human ductal carcinoma in situ and invasive tumors, in contrast to the normal mammary ducts. Rap1A protein expression is also higher in aggressive breast cancer cells (MDA-MB-231 and Hs578t relative to the weakly invasive MCF-7 cells or non-malignant MCF10A mammary cells. Depletion of Rap1A expression significantly impaired LPA-stimulated migration of breast cancer cells and invasiveness in three-dimensional Matrigel cultures. Furthermore, we found that β-arrestin2 associates with the actin binding protein IQGAP1 in breast cancer cells, and is necessary for the recruitment of IQGAP1 to the leading edge of migratory cells. Depletion of IQGAP1 blocked LPA-stimulated breast cancer cell invasion. Finally, we have identified that LPA enhances the binding of endogenous Rap1A to β-arrestin2, and also stimulates Rap1A and IQGAP1 to associate with LPA(1. Thus our data establish novel roles for Rap1A and IQGAP1 as critical regulators of LPA-induced breast cancer cell migration and invasion.

  6. Regulation of gene expression and subcellular protein distribution in MLO-Y4 osteocytic cells by lysophosphatidic acid: Relevance to dendrite outgrowth.

    Energy Technology Data Exchange (ETDEWEB)

    Waters, Katrina M.; Jacobs, Jon M.; Gritsenko, Marina A.; Karin, Norman J.

    2011-02-26

    Osteoblastic and osteocytic cells are highly responsive to the lipid growth factor lysophosphatidic acid (LPA) but the mechanisms by which LPA alters bone cell functions are largely unknown. A major effect of LPA on osteocytic cells is the stimulation of dendrite membrane outgrowth, a process that we predicted to require changes in gene expression and protein distribution. We employed DNA microarrays for global transcriptional profiling of MLO-Y4 osteocytic cells grown for 6 and 24h in the presence or absence of LPA. We identified 932 transcripts that displayed statistically significant changes in abundance of at least 1.25-fold in response to LPA treatment. Gene ontology (GO) analysis revealed that the regulated gene products were linked to diverse cellular processes, including DNA repair, response to unfolded protein, ossification, protein-RNA complex assembly, and amine biosynthesis. Gene products associated with the regulation of actin microfilament dynamics displayed the most robust expression changes, and LPA-induced dendritogenesis in vitro was blocked by the stress fiber inhibitor cytochalasin D. Mass spectrometry-based proteomic analysis of MLO-Y4 cells revealed significant LPA-induced changes in the abundance of 284 proteins at 6h and 844 proteins at 24h. GO analysis of the proteomic data linked the effects of LPA to cell processes that control of protein distribution and membrane outgrowth, including protein localization, protein complex assembly, Golgi vesicle transport, cytoskeleton-dependent transport, and membrane invagination/endocytosis. Dendrites were isolated from LPA-treated MLO-Y4 cells and subjected to proteomic analysis to quantitatively assess the subcellular distribution of proteins. Sets of 129 and 36 proteins were enriched in the dendrite fraction as compared to whole cells after 6h and 24h of LPA exposure, respectively. Protein markers indicated that membranous organelles were largely excluded from the dendrites. Highly represented among

  7. Lysophosphatidic acid signaling via LPA{sub 1} and LPA{sub 3} regulates cellular functions during tumor progression in pancreatic cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Kaori; Takahashi, Kaede; Yamasaki, Eri; Onishi, Yuka [Division of Molecular Oncology, Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Honoki, Kanya [Department of Orthopedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Tsujiuchi, Toshifumi, E-mail: ttujiuch@life.kindai.ac.jp [Division of Molecular Oncology, Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan)

    2017-03-01

    Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors exhibits a variety of biological effects, such as cell proliferation, motility and differentiation. The aim of this study was to evaluate the roles of LPA{sub 1} and LPA{sub 3} in cellular functions during tumor progression in pancreatic cancer cells. LPA{sub 1} and LPA{sub 3} knockdown cells were generated from PANC-1 cells. The cell motile and invasive activities of PANC-1 cells were inhibited by LPA{sub 1} and LPA{sub 3} knockdown. In gelatin zymography, LPA{sub 1} and LPA{sub 3} knockdown cells indicated the low activation of matrix metalloproteinase-2 (MMP-2) in the presence of LPA. Next, to assess whether LPA{sub 1} and LPA{sub 3} regulate cellular functions induced by anticancer drug, PANC-1 cells were treated with cisplatin (CDDP) for approximately 6 months. The cell motile and invasive activities of long-term CDDP treated cells were markedly higher than those of PANC-1 cells, correlating with the expression levels of LPAR1 and LPAR3 genes. In soft agar assay, the long-term CDDP treated cells formed markedly large sized colonies. In addition, the cell motile and invasive activities enhanced by CDDP were significantly suppressed by LPA{sub 1} and LPA{sub 3} knockdown as well as colony formation. These results suggest that LPA signaling via LPA{sub 1} and LPA{sub 3} play an important role in the regulation of cellular functions during tumor progression in PANC-1 cells. - Highlights: • The cell motile and invasive activities of PANC-1 cells were stimulated by LPA{sub 1} and LPA{sub 3}. • LPA{sub 1} and LPA{sub 3} enhanced MMP-2 activation in PANC-1 cells. • The expressions of LPAR1 and LPAR3 genes were elevated in PANC-1 cells treated with cisplatin. • The cell motile and invasive activities of PANC-1 cells treated with cisplatin were suppressed by LPA{sub 1} and LPA{sub 3} knockdown. • LPA{sub 1} and LPA{sub 3} are involved in the regulation of cellular functions during tumor

  8. Lysophosphatidic acid and sphingosine 1-phosphate metabolic pathways and their receptors are differentially regulated during decidualization of human endometrial stromal cells.

    Science.gov (United States)

    Brünnert, D; Sztachelska, M; Bornkessel, F; Treder, N; Wolczynski, S; Goyal, P; Zygmunt, M

    2014-10-01

    In the luteal phase, human endometrial stromal cells (HESCs) undergo proliferation, migration and differentiation during the decidualization process under the control of the ovarian steroids progesterone and estrogen. Proper decidualization of stromal cells is required for blastocyst implantation and the development of pregnancy. The proliferation, migration and differentiation of HESCs in decidualization do not require the presence of a blastocyst but are greatly accelerated during implantation. Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are potent bioactive lysophospholipids that have critical roles in various physiological and pathophysiological processes, including inflammation, angiogenesis and cancer. The expression of the enzymes involved in LPA and S1P turnover and their receptors in HESCs during decidualization has not been characterized yet. We found that the LPAR1 and LPAR6 and S1PR3 receptors are highly expressed in HESCs. LPAR1, autotaxin (ATX), an LPA producing enzyme and lipid phosphate phosphatase 3 were up-regulated during decidualization. Interestingly, the expression of all S1P receptor subtypes and LPA receptors (LPAR2-6) mRNA was down-regulated after decidualization. We found that SPHK1 is highly expressed in HESCs, and is up-regulated during decidualization. S1P phosphatase SGPP1 and S1P lyase SGPL1 are highly expressed in HESCs. SGPP1 mRNA expression was significantly up-regulated in decidualized HESCs. In conclusion, this study shows the first time that specific LPA and S1P receptors and their metabolizing enzymes are highly regulated in HESCs during decidualization. Furthermore, we suggest that LPAR1 receptor-mediated signaling in HESCs may be crucial in decidualization process. SPHK1 activity and high turnover of S1P and LPA might be essential for precise regulation of their signaling during decidualization of human endometrium and implantation. © The Author 2014. Published by Oxford University Press on behalf of the

  9. The Penicillium chrysogenum aclA gene encodes a broad-substrate-specificity acyl-coenzyme A ligase involved in activation of adipic acid, a side-chain precursor for cephem antibiotics.

    Science.gov (United States)

    Koetsier, Martijn J; Gombert, Andreas K; Fekken, Susan; Bovenberg, Roel A L; van den Berg, Marco A; Kiel, Jan A K W; Jekel, Peter A; Janssen, Dick B; Pronk, Jack T; van der Klei, Ida J; Daran, Jean-Marc

    2010-01-01

    Activation of the cephalosporin side-chain precursor to the corresponding CoA-thioester is an essential step for its incorporation into the beta-lactam backbone. To identify an acyl-CoA ligase involved in activation of adipate, we searched in the genome database of Penicillium chrysogenum for putative structural genes encoding acyl-CoA ligases. Chemostat-based transcriptome analysis was used to identify the one presenting the highest expression level when cells were grown in the presence of adipate. Deletion of the gene renamed aclA, led to a 32% decreased specific rate of adipate consumption and a threefold reduction of adipoyl-6-aminopenicillanic acid levels, but did not affect penicillin V production. After overexpression in Escherichia coli, the purified protein was shown to have a broad substrate range including adipate. Finally, protein-fusion with cyan-fluorescent protein showed co-localization with microbody-borne acyl-transferase. Identification and functional characterization of aclA may aid in developing future metabolic engineering strategies for improving the production of different cephalosporins.

  10. The Penicillium chrysogenum aclA gene encodes a broad-substrate-specificity acyl-coenzyme A ligase involved in activation of adipic acid, a side-chain precursor for cephem antibiotics

    NARCIS (Netherlands)

    Koetsier, Martijn J.; Gombert, Andreas K.; Fekken, Susan; Bovenberg, Roel A. L.; Van den Berg, Marco A.; Kiel, Jan A. K. W.; Jekel, Peter A.; Janssen, Dick B.; Pronk, Jack T.; Van der Klei, Ida J.; Daran, Jean-Marc

    Activation of the cephalosporin side-chain precursor to the corresponding CoA-thioester is an essential step for its incorporation into the P-lactam backbone. To identify an acyl-CoA ligase involved in activation of adipate, we searched in the genome database of Penicillium chrysogenum for putative

  11. Mutations in LACS2, a Long-Chain Acyl-Coenzyme A Synthetase, Enhance Susceptibility to Avirulent Pseudomonas syringae But Confer Resistance to Botrytis cinerea in Arabidopsis1[OA

    Science.gov (United States)

    Tang, Dingzhong; Simonich, Michael T.; Innes, Roger W.

    2007-01-01

    We identified an Arabidopsis (Arabidopsis thaliana) mutant, sma4 (symptoms to multiple avr genotypes4), that displays severe disease symptoms when inoculated with avirulent strains of Pseudomonas syringae pv tomato, although bacterial growth is only moderately enhanced compared to wild-type plants. The sma4 mutant showed a normal susceptible phenotype to the biotrophic fungal pathogen Erysiphe cichoracearum. Significantly, the sma4 mutant was highly resistant to a necrotrophic fungal pathogen, Botrytis cinerea. Germination of B. cinerea spores on sma4 mutant leaves was inhibited, and penetration by those that did germinate was rare. The sma4 mutant also showed several pleiotropic phenotypes, including increased sensitivity to lower humidity and salt stress. Isolation of SMA4 by positional cloning revealed that it encodes LACS2, a member of the long-chain acyl-CoA synthetases. LACS2 has previously been shown to be involved in cutin biosynthesis. We therefore tested three additional cutin-defective mutants for resistance to B. cinerea: att1 (for aberrant induction of type three genes), bodyguard, and lacerata. All three displayed an enhanced resistance to B. cinerea. Our results indicate that plant cutin or cuticle structure may play a crucial role in tolerance to biotic and abiotic stress and in the pathogenesis of B. cinerea. PMID:17434992

  12. Androgen-mediated cholesterol metabolism in LNCaP and PC-3 cell lines is regulated through two different isoforms of acyl-coenzyme A:Cholesterol Acyltransferase (ACAT).

    Science.gov (United States)

    Locke, Jennifer A; Wasan, Kishor M; Nelson, Colleen C; Guns, Emma S; Leon, Carlos G

    2008-01-01

    The objective of this work was to determine the effect of an androgen agonist, R1881, on intracellular cholesterol synthesis and esterification in androgen-sensitive (AS) prostate cancer (LNCaP) cells. We investigated the activity and expression of cholesterol metabolism enzymes, HMG-CoA-reductase and ACAT in the LNCaP and PC-3 (androgen-independent control) models. Microsomal PC-3 HMG-CoA-reductase activity was increased with R1881 despite having similar cholesterol levels while increased cholesterol levels in microsomes from LNCaPs treated with R1881 (L+) were associated with increased HMG-CoA reductase activity. Increased intracellular cholesteryl esters (CE) found in (L+) were not associated with an increased ACAT1 activity. There was no effect from androgen treatment on ACAT1 protein expression in theses cells; however, ACAT2 expression was induced upon R1881 treatment. In contrast, we found an increase in the in vitro ACAT1 activity in PC-3 cells treated with androgen (P+). Only ACAT1 expression was induced in P+. We further assessed the expression of STAT1 alpha, a transcriptional activator that modulates ACAT1 expression. STAT1 alpha expression and phosphorylation were induced in P+. To determine the role of the AR on ACAT1 expression and esterification, we treated PC-3 cells overexpressing the androgen receptor with R1881 (PAR+). AR expression was decreased in PAR+ cells; ACAT1 protein expression and cholesterol ester levels were also decreased, however, ACAT2 remained unchanged. STAT1 alpha expression was decreased in PAR+. Overall, these findings support the importance of cholesterol metabolism regulation within prostate cancer cells and unravel a novel role for STAT1 alpha in prostate cancer metabolism. (c) 2007 Wiley-Liss, Inc.

  13. A Dependence of Charmed Meson Production

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Gilvan Augusto [Rio de Janeiro, CBPF

    1992-03-01

    One report is presented of a recent direct measurement of the nucleon number (A) dependence of the production cross sections for the charmed mesons $D^0$ and $D^+$ using $\\pi^+_{-}$ and $K^+_{-}$ beams incident on a segmented target of Be, Al, Cu and W. The data derive from the experiment E769 - Hadroproductlon of Charm at Fermilab. The experimental apparatus is described together with the following analysis. Starting from a sample of -1500 D mesons in the range of $O< x_{f} <1$, the data are found to be well described by the parameterization $\\sigma_{A}$ = $\\sigma_{O}$ , with $\\alpha = 0.99 \\pm 0.03$. The $x_f$ dependence of $\\alpha$ is examined and the results obtained are compared with those of other .experiments and wl th -theoretical expectations based on perturbatlve QCD and on an EMC like model of nuclear shadowing

  14. Submucosal connective tissue-type mast cells contribute to the production of lysophosphatidic acid (LPA) in the gastrointestinal tract through the secretion of autotaxin (ATX)/lysophospholipase D (lysoPLD).

    Science.gov (United States)

    Mori, Ken; Kitayama, Joji; Aoki, Junken; Kishi, Yasuhiro; Shida, Dai; Yamashita, Hiroharu; Arai, Hiroyuki; Nagawa, Hirokazu

    2007-07-01

    Lysophosphatidic acid (LPA) is involved in a broad spectrum of biological activities, including wound healing and cancer metastasis. Autotaxin (ATX), originally isolated from a melanoma supernatant as a tumor cell motility-stimulating factor, has been shown to be molecularly identical to lysophospholipase D (lysoPLD), which is the main enzyme in the production of LPA. Although ATX/lysoPLD is known to be widely expressed in normal human tissues, the exact distribution of ATX-producing cells has not been fully investigated. In this study, we evaluated ATX/lysoPLD expression by immunohistochemical staining using a rat anti-ATX mAb in the human gastrointestinal tract and found that submucosal mast cells (MC) highly expressed this enzyme. This was confirmed by immunofluorescent double staining using mAbs to tryptase and chymase. Then, we isolated MC from human gastric tissue by an immunomagnetic method using CD117-microbeads and showed that a subpopulation of CD203c-positive MC showed positive staining for intracellular ATX/lysoPLD on flowcytometry. This was confirmed by Western blotting of the isolated cells. Moreover, a significant level of ATX/lysoPLD release could be detected in the culture supernatants of human MC by Western blot analysis. Our data suggest that submucosal MC play significant roles in various aspects of pathophysiology in the gastrointestinal tract by locally providing bioactive LPA through the production of ATX/lysoPLD.

  15. A clean-up technology for the simultaneous determination of lysophosphatidic acid and sphingosine-1-phosphate by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using a phosphate-capture molecule, Phos-tag.

    Science.gov (United States)

    Morishige, Jun-ichi; Urikura, Mai; Takagi, Haruko; Hirano, Kaoru; Koike, Tohru; Tanaka, Tamotsu; Satouchi, Kiyoshi

    2010-04-15

    Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are growth factor-like lipids having a phosphate group. The concentrations of these mediator lipids in blood are considered to be potential biomarkers for early detection of cancer or vascular diseases. Here, we report a method for simultaneous determination of LPA and S1P using Phos-tag, a zinc complex that specifically binds to a phosphate-monoester group. Although both LPA and S1P are hydrophilic compounds, we found that they acquire hydrophobic properties when they form complexes with Phos-tag. Based on this finding, we developed a method for the enrichment of LPA and S1P from biological samples. The first partition in a two-phase solvent system consisting of chloroform/methanol/water (1:1:0.9, v/v/v) is conducted for the removal of lipids. LPA and S1P are specifically extracted as Phos-tag complexes at the second partition by adding Phos-tag. The Phos-tag complexes of LPA and S1P are detectable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and quantifiable based on the relative intensities of ions using 17:0 LPA and C17 S1P as internal standards. The protocol was validated by analyses of these mediator lipids in calf serum, a rat brain and a lung. The clean-up protocol is rapid, requires neither thin-layer chromatography (TLC) nor liquid chromatography (LC), and is applicable to both blood and solid tissue samples. We believe that our protocol will be useful for a routine analysis of LPA and S1P in many clinical samples. 2010 John Wiley & Sons, Ltd.

  16. A dependently-typed construction of semi-simplicial types

    OpenAIRE

    Herbelin, Hugo

    2015-01-01

    International audience; This paper presents a dependently-typed construction of semi-simplicial sets in type theory where sets are taken to be types. This addresses an open question raised on the wiki of the special year on Univalent Foundations at the Institute of Advanced Study (2012-2013).

  17. CcpA-dependent carbon catabolite repression in bacteria

    NARCIS (Netherlands)

    Warner, JB; Lolkema, JS; Warner, Jessica B.

    2003-01-01

    Carbon catabolite repression (CCR) by transcriptional regulators follows different mechanisms in gram-positive and gram-negative bacteria. In gram-positive bacteria, CcpA-dependent CCR is mediated by phosphorylation of the phosphoenolpyruvate:sugar phosphotransferase system intermediate HPr at a

  18. A-dependent effects in high PT reactions

    International Nuclear Information System (INIS)

    Fields, T.

    1994-01-01

    A brief summary of A-dependent effects which have been observed in various high energy scattering processes from nuclear targets is given. Reactions which are discussed include dijet production, dihadron production, Drell-Yan, deep inelastic muon scattering, and low-P t hadron production. The data are described in terms of multiple scattering of a fast parton in nuclear matter. Some suggestions for future work are given

  19. Ectopic expression of Crambe abyssinica lysophosphatidic acid ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... cloned LPAAT from Crambe abyssinica Hochst. ex R. E. Fries (CaLPAAT, GenBank accession number. EF208088). To study its function ... system) and the endoplasmic reticulum (eukaryotic system) through a ... Unless stated, all molecular biological techniques (PCR, DNA, RNA and plasmid preparations ...

  20. A Dependent Hidden Markov Model of Credit Quality

    Directory of Open Access Journals (Sweden)

    Małgorzata Wiktoria Korolkiewicz

    2012-01-01

    Full Text Available We propose a dependent hidden Markov model of credit quality. We suppose that the "true" credit quality is not observed directly but only through noisy observations given by posted credit ratings. The model is formulated in discrete time with a Markov chain observed in martingale noise, where "noise" terms of the state and observation processes are possibly dependent. The model provides estimates for the state of the Markov chain governing the evolution of the credit rating process and the parameters of the model, where the latter are estimated using the EM algorithm. The dependent dynamics allow for the so-called "rating momentum" discussed in the credit literature and also provide a convenient test of independence between the state and observation dynamics.

  1. Eflucimibe. Pierre Fabre/Eli Lilly.

    Science.gov (United States)

    Burnett, John R

    2003-03-01

    Eflucimibe is an acyl coenzyme A:cholesterol acyltransferase inhibitor under development by Pierre Fabre SA and Eli Lilly & Co for the potential treatment of hypercholesterolemia and atherosclerosis. Phase II clinical trials commenced during 2002.

  2. ACAT Inhibition and Progression of Carotid Atherosclerosis in Patients With Familial Hypercholesterolemia The CAPTIVATE Randomized Trial

    NARCIS (Netherlands)

    Meuwese, Marijn C.; de Groot, Eric; Duivenvoorden, Raphaël; Trip, Mieke D.; Ose, Leiv; Maritz, Frans J.; Basart, Dick C. G.; Kastelein, John J. P.; Habib, Rafik; Davidson, Michael H.; Zwinderman, Aeilko H.; Schwocho, Lee R.; Stein, Evan A.

    2009-01-01

    Context Inhibition of acyl coenzyme A: cholesterol acyltransferase (ACAT), an intracellular enzyme involved in cholesterol accumulation, with pactimibe was developed to assist in the prevention of cardiovascular disease. Objective To evaluate the efficacy and safety of pactimibe in inhibition of

  3. Reference: 783 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available xpression of the Arabidopsis 10-kilodalton acyl-coenzyme A-binding protein ACBP6 en...phospholipid metabolism in Arabidopsis, including the possibility of ACBP6 in the cytosolic trafficking of phosphatidylcholine. Overe

  4. Lysophosphatidic Acid Regulation and Roles in Human Prostate Cancer

    National Research Council Canada - National Science Library

    Spiegel, Sarah

    2004-01-01

    ..., stimulating motility and inducing tumor cell invasion, and regulating neovascularization. Progress in understanding LPA actions has accelerated with the discovery that it is a ligand of several G protein coupled cell surface receptors (GPCRs...

  5. Lysophosphatidic Acid Regulation and Roles in Human Prostate Cancer

    Science.gov (United States)

    2006-08-01

    Received 23 June 2005 C©2005 Biochemical Society Glycoconjugate Journal 20, 39–47, 2004 C© 2004 Kluwer Academic Publishers. Manufactured in The Netherlands ...hyperproliferative skin disorders, including psoriasis and squa- mous cell carcinoma [100,101] where programmed cell death is aberrant. Ganglioside GM3 was shown to

  6. DksA-dependent transcriptional regulation in Salmonella experiencing nitrosative stress

    Directory of Open Access Journals (Sweden)

    Matthew A Crawford

    2016-03-01

    Full Text Available Redox-based signaling is fundamental to the capacity of bacteria to sense, and respond to, nitrosative and oxidative stress encountered in natural and host environments. The conserved RNA polymerase regulatory protein DksA is a thiol-based sensor of reactive nitrogen and oxygen species. DksA-dependent transcriptional control promotes antinitrosative and antioxidative defenses that contribute to Salmonella pathogenesis. The specific adaptive changes mediated by DksA in response to reactive species, however, have not been elucidated. Herein, we characterize DksA-dependent changes in gene expression in Salmonella enterica experiencing nitrosative stress. Genome-wide expression analysis of wild-type and delta-dksA Salmonella exposed to the nitric oxide (•NO donor DETA NONOate demonstrated •NO- and DksA-dependent regulatory control of 427 target genes. Transcriptional changes centered primarily on genes encoding aspects of cellular metabolism. Several antioxidants and oxidoreductases important in redox buffering, •NO detoxification, and damage repair were also observed to be up-regulated in an •NO- and DksA-dependent manner. Compared to wild-type bacteria, •NO-treated delta-dksA Salmonella exhibited a de-repression of genes encoding components of iron homeostasis and failed to activate sulfur assimilation and cysteine biosynthetic operons. As cysteine is integral to efficient antinitrosative and antioxidative defense and repair programs, we further examined the redox-responsive transcriptional control of cysteine biosynthesis by DksA. These investigations revealed that the activation of genes comprising cysteine biosynthesis also occurs in response to hydrogen peroxide, is dependent upon the redox-sensing zinc finger domain of DksA, and requires the transcriptional regulator CysB. Our observations demonstrate that DksA mediates global adaptation to nitrosative stress in Salmonella and provide unique insight into a novel regulatory mechanism

  7. A terapia multifamiliar e a dependência química

    OpenAIRE

    Seadi, Susana Maria Sastre

    2007-01-01

    A dependência química é um fenômeno multifatorial e necessita de distintas abordagens terapêuticas. A inclusão da família, não como coadjuvante ou colaboradora, mas como parte do tratamento dos problemas com álcool e outras drogas vem crescendo no Brasil nos últimos anos. No entanto, são poucos os estudos sobre os fatores que podem contribuir para a adesão ao tratamento e o presente trabalho se propõe a verificar a influência da participação da família na adesão ao tratamento. Esta dissertaçã...

  8. A Dependent Insurance Risk Model with Surrender and Investment under the Thinning Process

    Directory of Open Access Journals (Sweden)

    Wenguang Yu

    2015-01-01

    Full Text Available A dependent insurance risk model with surrender and investment under the thinning process is discussed, where the arrival of the policies follows a compound Poisson-Geometric process, and the occurrences of the claim and surrender happen as the p-thinning process and the q-thinning process of the arrival process, respectively. By the martingale theory, the properties of the surplus process, adjustment coefficient equation, the upper bound of ruin probability, and explicit expression of ruin probability are obtained. Moreover, we also get the Laplace transformation, the expectation, and the variance of the time when the surplus reaches a given level for the first time. Finally, various trends of the upper bound of ruin probability and the expectation and the variance of the time when the surplus reaches a given level for the first time are simulated analytically along with changing the investment size, investment interest rates, claim rate, and surrender rate.

  9. Continuously rethinking the definition of influenza for surveillance systems: a Dependent Bayesian Expert System.

    Science.gov (United States)

    Alemi, Farrokh; Atherton, Martin J; Pattie, David C; Torii, Manabu

    2013-08-01

    In the Electronic Surveillance System for the Early Notification of Community-based Epidemics (ESSENCE), influenza was originally defined by a list of 29 and later by a list of 12 diagnosis codes. This article describes a dependent Bayesian procedure designed to improve the ESSENCE system and exploit multiple sources of information without being biased by redundancy. We obtained 13,096 cases within the Armed Forces Health Longitudinal Technological Application electronic medical records that included an influenza laboratory test. A Dependent Bayesian Expert System (D-BESt) was used to predict influenza from diagnoses, symptoms, reason for visit, temperature, month of visit, category of enrollment, and demographics. For each case, D-BESt sequentially selects the most discriminating piece of information, calculates its likelihood ratio conditioned on previously selected information, and updates the case's probability of influenza. When the analysis was limited to definitions based on diagnoses and was applied to a sample of patients for whom laboratory tests had been ordered, the areas under the receiver operating characteristic curve (AUCs) for the previous (29-diagnosis) and current (12-diagnosis) ESSENCE lists and the D-BESt algorithm were, respectively, 0.47, 0.36, and 0.77. Including other sources of information further improved the AUC for D-BESt to 0.79. At the best cutoff point for D-BESt, where the receiver operating characteristic curve for D-BESt is farthest from the diagonal line, the D-BESt algorithm correctly classified 84% of cases (specificity = 88%, sensitivity = 62%). In comparison, the current ESSENCE approach of using a list of 12 diagnoses correctly classified only 31% of this sample of cases (specificity = 29%, sensitivity = 42%). False alarms in ESSENCE surveillance systems can be reduced if a probabilistic dynamic learning system is used.

  10. Identification and characterization of AckA-dependent protein acetylation in Neisseria gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Deborah M B Post

    Full Text Available Neisseria gonorrhoeae, the causative agent of gonorrhea, has a number of factors known to contribute to pathogenesis; however, a full understanding of these processes and their regulation has proven to be elusive. Post-translational modifications (PTMs of bacterial proteins are now recognized as one mechanism of protein regulation. In the present study, Western blot analyses, with an anti-acetyl-lysine antibody, indicated that a large number of gonococcal proteins are post-translationally modified. Previous work has shown that Nε-lysine acetylation can occur non-enzymatically with acetyl-phosphate (AcP as the acetyl donor. In the current study, an acetate kinase mutant (1291ackA, which accumulates AcP, was generated in N. gonorrhoeae. Broth cultures of N. gonorrhoeae 1291wt and 1291ackA were grown, proteins extracted and digested, and peptides containing acetylated-lysines (K-acetyl were affinity-enriched from both strains. Mass spectrometric analyses of these samples identified a total of 2686 unique acetylation sites. Label-free relative quantitation of the K-acetyl peptides derived from the ackA and wild-type (wt strains demonstrated that 109 acetylation sites had an ackA/wt ratio>2 and p-values <0.05 in at least 2/3 of the biological replicates and were designated as "AckA-dependent". Regulated K-acetyl sites were found in ribosomal proteins, central metabolism proteins, iron acquisition and regulation proteins, pilus assembly and regulation proteins, and a two-component response regulator. Since AckA is part of a metabolic pathway, comparative growth studies of the ackA mutant and wt strains were performed. The mutant showed a growth defect under aerobic conditions, an inability to grow anaerobically, and a defect in biofilm maturation. In conclusion, the current study identified AckA-dependent acetylation sites in N. gonorrhoeae and determined that these sites are found in a diverse group of proteins. This work lays the foundation for

  11. Extreme geographies: a response from a dependent semi-periphery of the post-neoliberal Europe

    Directory of Open Access Journals (Sweden)

    James Riding

    2017-06-01

    Full Text Available We live in a time of paranoid borderism, a time of intense paranoia of the Other, and a time where the privileging of the nation state as the symbolic container of space, our territory, seems to have made a lurid return to the European continent. The consequences of this socio-spatial ordering and othering, the legacy of Euclidian thinking, and Cartesian models of knowing the world, can become an extreme geography: a form of cartographic cleansing that seriously needs to be addressed. In this short response to the Fennia Lecture given by Professor Henk van Houtum on Extreme Geographies, I offer a report from a region that has become a dependent semi-periphery of the new largely neoliberal Europe that emerged post-1989: a new Europe that is now entering a post-neoliberal era and is becoming increasingly neofascist. I draw from this region as a warning from history, and argue that the hopeful politics of the New Left in the former Yugoslavia provide an answer. The New Left, as it has been termed, in the Post-Yugoslav space, articulates the need for a new radically democratic European project: a project that is no longer neoliberal, but equally a project that does not turn to a nostalgic nationalism, a neofascism, or indeed any other form of authoritarian capitalism.

  12. Nuclear Envelope Protein SUN2 Promotes Cyclophilin-A-Dependent Steps of HIV Replication

    Directory of Open Access Journals (Sweden)

    Xavier Lahaye

    2016-04-01

    Full Text Available During the early phase of replication, HIV reverse transcribes its RNA and crosses the nuclear envelope while escaping host antiviral defenses. The host factor Cyclophilin A (CypA is essential for these steps and binds the HIV capsid; however, the mechanism underlying this effect remains elusive. Here, we identify related capsid mutants in HIV-1, HIV-2, and SIVmac that are restricted by CypA. This antiviral restriction of mutated viruses is conserved across species and prevents nuclear import of the viral cDNA. Importantly, the inner nuclear envelope protein SUN2 is required for the antiviral activity of CypA. We show that wild-type HIV exploits SUN2 in primary CD4+ T cells as an essential host factor that is required for the positive effects of CypA on reverse transcription and infection. Altogether, these results establish essential CypA-dependent functions of SUN2 in HIV infection at the nuclear envelope.

  13. The DnaE polymerase from Deinococcus radiodurans features RecA-dependent DNA polymerase activity.

    Science.gov (United States)

    Randi, Lorenzo; Perrone, Alessandro; Maturi, Mirko; Dal Piaz, Fabrizio; Camerani, Michela; Hochkoeppler, Alejandro

    2016-12-01

    We report in the present study on the catalytic properties of the Deinococcus radiodurans DNA polymerase III α subunit (αDr). The αDr enzyme was overexpressed in Escherichia coli, both in soluble form and as inclusion bodies. When purified from soluble protein extracts, αDr was found to be tightly associated with E. coli RNA polymerase, from which αDr could not be dissociated. On the contrary, when refolded from inclusion bodies, αDr was devoid of E. coli RNA polymerase and was purified to homogeneity. When assayed with different DNA substrates, αDr featured slower DNA extension rates when compared with the corresponding enzyme from E. coli (E. coli DNA Pol III, αEc), unless under high ionic strength conditions or in the presence of manganese. Further assays were performed using a ssDNA and a dsDNA, whose recombination yields a DNA substrate. Surprisingly, αDr was found to be incapable of recombination-dependent DNA polymerase activity, whereas αEc was competent in this action. However, in the presence of the RecA recombinase, αDr was able to efficiently extend the DNA substrate produced by recombination. Upon comparing the rates of RecA-dependent and RecA-independent DNA polymerase activities, we detected a significant activation of αDr by the recombinase. Conversely, the activity of αEc was found maximal under non-recombination conditions. Overall, our observations indicate a sharp contrast between the catalytic actions of αDr and αEc, with αDr more performing under recombination conditions, and αEc preferring DNA substrates whose extension does not require recombination events. © 2016 The Author(s).

  14. CcpA-Dependent Carbohydrate Catabolite Repression Regulates Galactose Metabolism in Streptococcus oligofermentans

    Science.gov (United States)

    Cai, Jun; Qi, Fengxia

    2012-01-01

    Streptococcus oligofermentans is an oral commensal that inhibits the growth of the caries pathogen Streptococcus mutans by producing copious amounts of H2O2 and that grows faster than S. mutans on galactose. In this study, we identified a novel eight-gene galactose (gal) operon in S. oligofermentans that was comprised of lacABCD, lacX, and three genes encoding a galactose-specific transporter. Disruption of lacA caused more growth reduction on galactose than mutation of galK, a gene in the Leloir pathway, indicating that the principal role of this operon is in galactose metabolism. Diauxic growth was observed in cultures containing glucose and galactose, and a luciferase reporter fusion to the putative gal promoter demonstrated 12-fold repression of the operon expression by glucose but was induced by galactose, suggesting a carbon catabolite repression (CCR) control in galactose utilization. Interestingly, none of the single-gene mutations in the well-known CCR regulators ccpA and manL affected diauxic growth, although the operon expression was upregulated in these mutants in glucose. A double mutation of ccpA and manL eliminated glucose repression of galactose utilization, suggesting that these genes have parallel functions in regulating gal operon expression and mediating CCR. Electrophoretic mobility shift assays demonstrated binding of CcpA to the putative catabolite response element motif in the promoter regions of the gal operon and manL, suggesting that CcpA regulates CCR through direct regulation of the transcription of the gal operon and manL. This provides the first example of oral streptococci using two parallel CcpA-dependent CCR pathways in controlling carbohydrate metabolism. PMID:22609925

  15. Effects of a Dependent Group Contingency on the Verbal Interactions of Middle School Students with Emotional Disturbance

    OpenAIRE

    Hansen, S.; Lignugaris/Kraft, Benjamin

    2005-01-01

    This study examined the effects of a dependent group contingency to increase positive verbal interactions among nine middle school-aged males in a self-contained classroom. Prior to implementing the group contingency, the students received social skills instruction. A withdrawal experimental design was then used to evaluate the effects of the dependent group contingency. Students' positive verbal interactions increased and negative verbal interactions decreased with the implementation of the ...

  16. A-dependence of the charm production cross section in 320 GeV/cπ- interactions

    International Nuclear Information System (INIS)

    Cobbaert, H.; Roosen, R.; Catanesi, M.G.; Muciaccia, M.T.; Natali, S.; Nuzzo, S.; Ruggieri, F.; Carboni, G.; Crosetti, G.; Fidecaro, M.; Gerke, C.; Musset, P.; Poulard, G.; Sletten, H.; Coupland, M.; Roberts, I.G.; Trent, P.T.; Bartley, J.H.; Conboy, J.; Duff, B.G.; Esten, M.J.; Fennel, P.; Harrison, P.F.; De Vincenzi, M.; Di Liberto, S.; Frenkel, A.; Lamanna, E.; Marini, G.; Martellotti, G.; Nigro, A.; Penso, G.; Petrera, S.; Pistilli, P.; Romano, G.; Rosa, G.; Sciubba, A.; Alessandro, B.; Bisi, V.; Gamba, D.; Ramello, L.; Riccati, L.

    1987-01-01

    Using a 320 GeV/cπ - beam incident on three different target materials Al, Fe, and U, the A-dependence of charm production is studied by measuring the yield of prompt single muons. Parametrizing the charm cross section as σ cc (π - A) = σ 0 A α the measured α values are α(μ + ) = 0.76±0.08 and α(μ - ) = 0.83±0.06. (orig.)

  17. Impact of histone demethylase KDM3A-dependent AP-1 transactivity on hepatotumorigenesis induced by PI3K activation.

    Science.gov (United States)

    Nakatsuka, T; Tateishi, K; Kudo, Y; Yamamoto, K; Nakagawa, H; Fujiwara, H; Takahashi, R; Miyabayashi, K; Asaoka, Y; Tanaka, Y; Ijichi, H; Hirata, Y; Otsuka, M; Kato, M; Sakai, J; Tachibana, M; Aburatani, H; Shinkai, Y; Koike, K

    2017-11-09

    Epigenetic gene regulation linked to oncogenic pathways is an important focus of cancer research. KDM3A, a histone H3 lysine 9 (H3K9) demethylase, is known to have a pro-tumorigenic function. Here, we showed that KDM3A contributes to liver tumor formation through the phosphatidylinositol 3-kinase (PI3K) pathway, which is often activated in hepatocellular carcinoma. Loss of Kdm3a attenuated tumor formation in Pik3ca transgenic (Tg) mouse livers. Transcriptome analysis of pre-cancerous liver tissues revealed that the expression of activator protein 1 (AP-1) target genes was induced by PI3K activation, but blunted upon Kdm3a ablation. Particularly, the expression of Cd44, a liver cancer stem marker, was regulated by AP-1 in a Kdm3a-dependent manner. We identified Cd44-positive hepatocytes with epithelial-mesenchymal transition-related expression profiles in the Pik3ca Tg liver and confirmed their in vivo tumorigenic capacity. Notably, the number and tumor-initiating capacity of Cd44-positive hepatocytes were governed by Kdm3a. As a mechanism in Kdm3a-dependent AP-1 transcription, Kdm3a recruited c-Jun to the AP-1 binding sites of Cd44, Mmp7 and Pdgfrb without affecting c-Jun expression. Moreover, Brg1, a component of the SWI/SNF chromatin remodeling complex, interacted with c-Jun in a Kdm3a-dependent manner and was bound to the AP-1 binding site of these genes. Finally, KDM3A and c-JUN were co-expressed in 33% of human premalignant lesions with PI3K activation. Our data suggest a critical role for KDM3A in the PI3K/AP-1 oncogenic axis and propose a novel strategy for inhibition of KDM3A against liver tumor development under PI3K pathway activation.

  18. A-dependence of nuclear transparency in quasielastic A(e,e'p) at high Q2

    International Nuclear Information System (INIS)

    O'Neill, T.G.; Lorenzon, W.; Arrington, J.

    1994-01-01

    The A-dependence of the quasielastic A(e,e'p) reaction has been studied with 3 H, C, Fe, and Au nuclei at momentum transfers Q 2 = 1, 3, 5, and 6.8(GeV/c) 2 . The authors extract the nuclear transparency T(A,Q 2 ), a measure of the average probability of escape of a proton from a nucleus A. Several calculations predict a significant increase in T with momentum transfer, a phenomenon known as color transparency. No statistically significant rise is seen for any of the nuclei studied

  19. A-dependence of the charm production cross section in 300 GeV/c proton interactions

    International Nuclear Information System (INIS)

    Cobbaert, H.; Roosen, R.; Catanesi, M.G.; Muciaccia, M.T.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ruggieri, F.; Carboni, G.; Crosetti, G.; Fidecaro, M.; Gerke, C.; Poulard, G.; Sletten, H.; Coupland, M.; Roberts, I.G.; Trent, P.T.; Bartley, J.H.; Conboy, J.E.; Esten, M.J.; Fennel, P.; Harrison, P.F.; De Vincenzi, M.; Di Liberto, S.; Frenkel, A.; Iori, M.; Lamanna, E.; Marini, G.; Martellotti, G.; Nigro, A.; Parisi, A.; Penso, G.; Petrera, S.; Pistilli, P.; Romano, G.; Rosa, G.; Sciubba, A.; Alessandro, B.; Bisi, V.; Gamba, D.; Ramello, L.; Riccati, L.

    1988-01-01

    The A-dependence of the charm production cross section is determined by measuring the yield of prompt single muons in a beam-dump experiment, using a 300 GeV/c proton beam on Al, Fe, and U targets. Assuming that the production cross section varies as A α , we obtain α(μ + ) = 0.79±0.12 and α(μ - ) = 0.76±0.13 in the kinematical region Χ F > or approx. 0.1 of the charm. (orig.)

  20. Analysis of hydroxycinnamic acid degradation in Agrobacterium fabrum reveals a coenzyme A-dependent, beta-oxidative deacetylation pathway.

    Science.gov (United States)

    Campillo, Tony; Renoud, Sébastien; Kerzaon, Isabelle; Vial, Ludovic; Baude, Jessica; Gaillard, Vincent; Bellvert, Floriant; Chamignon, Cécile; Comte, Gilles; Nesme, Xavier; Lavire, Céline; Hommais, Florence

    2014-06-01

    The soil- and rhizosphere-inhabiting bacterium Agrobacterium fabrum (genomospecies G8 of the Agrobacterium tumefaciens species complex) is known to have species-specific genes involved in ferulic acid degradation. Here, we characterized, by genetic and analytical means, intermediates of degradation as feruloyl coenzyme A (feruloyl-CoA), 4-hydroxy-3-methoxyphenyl-β-hydroxypropionyl-CoA, 4-hydroxy-3-methoxyphenyl-β-ketopropionyl-CoA, vanillic acid, and protocatechuic acid. The genes atu1416, atu1417, and atu1420 have been experimentally shown to be necessary for the degradation of ferulic acid. Moreover, the genes atu1415 and atu1421 have been experimentally demonstrated to be essential for this degradation and are proposed to encode a phenylhydroxypropionyl-CoA dehydrogenase and a 4-hydroxy-3-methoxyphenyl-β-ketopropionic acid (HMPKP)-CoA β-keto-thiolase, respectively. We thus demonstrated that the A. fabrum hydroxycinnamic degradation pathway is an original coenzyme A-dependent β-oxidative deacetylation that could also transform p-coumaric and caffeic acids. Finally, we showed that this pathway enables the metabolism of toxic compounds from plants and their use for growth, likely providing the species an ecological advantage in hydroxycinnamic-rich environments, such as plant roots or decaying plant materials.

  1. A dependence that empowers-the meaning of the conditions that enable a good life with bipolar disorder.

    Science.gov (United States)

    Rusner, Marie; Carlsson, Gunilla; Brunt, David; Nyström, Maria

    2010-02-09

    The extensive suffering related to a complex life situation with bipolar disorder (BD) and the reported difference between care needs and the needs that are actually met implicates that there are still questions about management of life with BD that need to be answered. The present study therefore aims to describe the meaning of the conditions that enable a good life with BD. Ten persons, six women and four men (aged 30-61), diagnosed with BD were interviewed. A reflective lifeworld perspective based on phenomenological philosophy was used. The findings present the essential meaning of the conditions that enable a good life with BD as a dependence that empowers, which is further described by its constituents: "turning the course of life," "protecting oneself from running out of energy," "being needed," "being oneself through reliable others," "personal landmarks for navigating through life." A voluntary chosen dependence, as described in the present study, is a new approach of care that enables a good life with BD, while enhancing own power, freedom, and control. The conditions that enable a good life with BD are more than separate supporting measures. Therefore a holistic perspective is preferable while providing care for individuals with BD.

  2. Group boundary permeability moderates the effect of a dependency meta-stereotype on help-seeking behaviour.

    Science.gov (United States)

    Zhang, Lange; Kou, Yu; Zhao, Yunlong; Fu, Xinyuan

    2016-08-01

    Previous studies have found that when low-status group members are aware that their in-group is stereotyped as dependent by a specific out-group (i.e. a dependency meta-stereotype is salient), they are reluctant to seek help from the high-status out-group to avoid confirming the negative meta-stereotype. However, it is unclear whether low-status group members would seek more help in the context of a salient dependency meta-stereotype when there is low (vs. high) group boundary permeability. Therefore, we conducted two experiments to examine the moderating effect of permeability on meta-stereotype confirmation with a real group. In study 1, we manipulated the salience of the dependency meta-stereotype, measured participants' perceived permeability and examined their help-seeking behaviour in a real-world task. Participants who perceived low permeability sought more help when the meta-stereotype was salient (vs. not salient), whereas participants who perceived high permeability sought the same amount of help across conditions. In study 2, we manipulated the permeability levels and measured the dependency meta-stereotype. Participants who endorsed a high-dependency meta-stereotype sought more help than participants who endorsed a low-dependency meta-stereotype; this effect was particularly strong in the low-permeability condition. The implications of these results for social mobility and intergroup helping are discussed. © 2015 International Union of Psychological Science.

  3. Marriage is a dependent risk factor for mortality of colon adenocarcinoma without a time-varying effect.

    Science.gov (United States)

    Liu, Minling; Li, Lixian; Yu, Wei; Chen, Jie; Xiong, Weibin; Chen, Shuang; Yu, Li

    2017-03-21

    It has been well recognized that the effects of many prognostic factors could change during long-term follow-up. Although marriage has been proven to be a significant prognostic factor for the survival of colon cancer, whether the effect of marriage is constant with time remain unknown. This study analyzed the impact of marital status on the mortality of colon cancer patients with an extended Cox model that allowed for time-varying effects. We identified 71,955 patients who underwent colectomy between 2004 and 2009 to treat colon adenocarcinoma from the Surveilance, Epidemiology and End Results Database. The multivariate extended Cox model was used to evaluate the effect of marital status on all-cause mortality, while the Fine-Gray competing risks model was used for colon cancer-specific mortality, with death from other causes as the competing risk. The unmarried patients carried a 1.37-fold increased risk of all-cause mortality compared with the married patients (95%CI: 1.33-1.40; pMarriage is a dependent prognosis factor for survival of surgically treated colon adenocarcinoma patients. Psychological interventions are suggested to improve receipt of treatment among unmarried patients, as their poor survival may be due to the inefficient treatment.

  4. 'There is a dependent patient in our home': designing and disseminating a family caregiving program through YouTube.

    Science.gov (United States)

    Abu Kamel, Andaleeb

    2016-06-01

    Family members play a major role in providing care for older people and long-term dependent patients, especially in developing countries where there is a lack of specialized nursing homes and specialized home-visiting programs. Family members are rarely provided with sufficient information or training to provide home care for their dependent relatives. There are inadequate home caregiving educational resources directed to Arabic-speaking caregivers, either in written or in audiovisual presentations. The aims of the present study were (i) to present the process of designing a caregiving educational program entitled 'there is a dependent patient in our home', with an intention to be culturally and linguistically appropriate for a specific Arab-speaking population, and (ii) to present the experience of disseminating the program through YouTube, to be accessible for a wide range of caregivers. The program was a product of a process involving seven phases, starting with a review of the literature and ending with disseminating 17 short 'caregiving' videos on YouTube, the most popular video-sharing website. The program presented necessary skills, instructions, and information that enabled caregivers to provide safe and competent daily caring activities for their functionally dependent relative or older adults at home. The program was registered in the Jordan National Library. After 2 months of broadcasting it on YouTube, the number of views exceeded 6800. Many constructive comments were received from caregivers. Language, simplicity, and attractiveness of the program were judged as the areas of satisfaction by the viewers, whereas lack of a few topics such as verbal communication with patients and dealing with daily caregivers' burden and stressors were the main reasons of dissatisfaction. This program was an endeavor to provide the Arabic library with a home caregiving resource. Adequate advertisement of the program would encourage health providers to search for and use

  5. Avasimibe Pfizer.

    Science.gov (United States)

    Burnett, John R; Huff, Murray W

    2002-09-01

    Avasimibe (also known as CI-1011 or PD-148515) is a selective acyl-coenzyme A:cholesterol O-acyltransferase (ACAT) inhibitory lipid-regulating agent under development by Pfizer (formerly Parke-Davis) for the potential treatment of hyperlipidemia and atherosclerosis. The compound is currently undergoing phase III clinical trials [371470].

  6. The biochemical textural and sensory properties of frozen stored ...

    African Journals Online (AJOL)

    Tests related to muscle integrity ( -hydroxy-acyl-coenzyme –A dehydrogenase activities in muscle extracts), myofibrillar protein denaturation (Ca2+-ATPase activities in actomyosin extracts) showed that storage time affected the integrity of muscles and caused structural changes to myosin (or 'actomyosin'). The water ...

  7. Experimental evidence for protein oxidative damage and altered antioxidant defense in patients with medium-chain acyl-CoA dehydrogenase deficiency

    NARCIS (Netherlands)

    Derks, Terry G J; Touw, Catharina M L; Ribas, Graziela S; Biancini, Giovana B; Vanzin, Camila S; Negretto, Giovanna; Mescka, Caroline P; Reijngoud, Dirk Jan; Smit, G Peter A; Wajner, Moacir; Vargas, Carmen R

    The objective of this study was to test whether macromolecule oxidative damage and altered enzymatic antioxidative defenses occur in patients with medium-chain acyl coenzyme A dehydrogenase (MCAD) deficiency. We performed a cross-sectional observational study of in vivo parameters of lipid and

  8. Formation of Native and Non-native Interactions in Ensembles of Denatured ACBP Molecules from Paramagnetic Relaxation Enhancement Studies

    DEFF Research Database (Denmark)

    Kristjansdottir, S.; Lindorff-Larsen, Kresten; Fieber, W.

    2005-01-01

    in the denatured states with those in the transition state for folding we also provided new insights into the mechanism of formation of the native state of this protein. Keywords: protein folding; denatured state; NMR; molecular dynamics; structural studies Abbreviations: ACBP, acyl coenzyme A binding protein; Gu...

  9. Disturbed hepatic carbohydrate management during high metabolic demand in medium-chain acyl-CoA dehydrogenase (MCAD)-deficient mice

    NARCIS (Netherlands)

    Herrema, H.J.; Derks, T.G.; Dijk, van T.H.; Bloks, V.W.; Gerding, A.; Havinga, R.; Tietge, U.J.; Müller, M.R.; Smit, G.P.; Kuipers, F.; Reijngoud, D.J.

    2008-01-01

    Medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) catalyzes crucial steps in mitochondrial fatty acid oxidation, a process that is of key relevance for maintenance of energy homeostasis, especially during high metabolic demand. To gain insight into the metabolic consequences of MCAD deficiency

  10. Disturbed hepatic carbohydrate management during high metabolic demand in medium-chain acyl-CoA dehydrogenase (MCAD)-deficient mice

    NARCIS (Netherlands)

    Herrema, Hillechien; Derks, Terry; van Dijk, Theo H.; Bloks, Vincent W.; Gerding, Albert; Havinga, Rick; Tietge, Uwe J. F.; Müller, Michael; Smit, G. Peter A.; Kuipers, Folkert; Reijngoud, Dirk-Jan

    Medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) catalyzes crucial steps in mitochondrial fatty acid oxidation, a process that is of key relevance for maintenance of energy homeostasis, especially during high metabolic demand. To gain insight into the metabolic consequences of MCAD deficiency

  11. Safe and unsafe duration of fasting for children with MCAD deficiency

    NARCIS (Netherlands)

    Derks, Terry G J; van Spronsen, Francjan J; Rake, Jan Peter; van der Hilst, Christian S; Span, Mark M; Smit, G Peter A

    OBJECTIVE: To study the safe and unsafe duration of fasting in children with medium chain acyl-Coenzyme A dehydrogenase (MCAD) deficiency, the literature and the database on Dutch MCAD-deficient patients were searched for data on fasting studies in patients with MCAD deficiency. MATERIALS AND

  12. The difference between observed and expected prevalence of MCAD deficiency in The Netherlands: a genetic epidemiological study

    NARCIS (Netherlands)

    Derks, Terry G. J.; Duran, Marinus; Waterham, Hans R.; Reijngoud, Dirk-Jan; ten Kate, Leo P.; Smit, G. Peter A.

    2005-01-01

    Medium chain acyl coenzyme A dehydrogenase ( MCAD) deficiency is assumed to be the most common inherited disorder of mitochondrial fatty acid oxidation. Few reports mention the difference between the expected and observed prevalence of MCAD deficiency on the basis of the carrier frequency in the

  13. The difference between observed and expected prevalence of MCAD deficiency in The Netherlands : a genetic epidemiological study

    NARCIS (Netherlands)

    Derks, Terry G J; Duran, Marinus; Waterham, Hans R; Reijngoud, Dirk-Jan; Ten Kate, Leo P; Smit, G Peter A

    Medium chain acyl coenzyme A dehydrogenase ( MCAD) deficiency is assumed to be the most common inherited disorder of mitochondrial fatty acid oxidation. Few reports mention the difference between the expected and observed prevalence of MCAD deficiency on the basis of the carrier frequency in the

  14. L-histidine inhibits production of lysophosphatidic acid by the tumor-associated cytokine, autotaxin

    Directory of Open Access Journals (Sweden)

    Schiffmann Elliott

    2005-02-01

    Full Text Available Abstract Background Autotaxin (ATX, NPP-2, originally purified as a potent tumor cell motility factor, is now known to be the long-sought plasma lysophospholipase D (LPLD. The integrity of the enzymatic active site, including three crucial histidine moieties, is required for motility stimulation, as well as LPLD and 5'nucleotide phosphodiesterase (PDE activities. Except for relatively non-specific chelation agents, there are no known inhibitors of the ATX LPLD activity. Results We show that millimolar concentrations of L-histidine inhibit ATX-stimulated but not LPA-stimulated motility in two tumor cell lines, as well as inhibiting enzymatic activities. Inhibition is reversed by 20-fold lower concentrations of zinc salt. L-histidine has no significant effect on the Km of LPLD, but reduces the Vmax by greater than 50%, acting as a non-competitive inhibitor. Several histidine analogs also inhibit the LPLD activity of ATX; however, none has greater potency than L-histidine and all decrease cell viability or adhesion. Conclusion L-histidine inhibition of LPLD is not a simple stoichiometric chelation of metal ions but is more likely a complex interaction with a variety of moieties, including the metal cation, at or near the active site. The inhibitory effect of L-histidine requires all three major functional groups of histidine: the alpha amino group, the alpha carboxyl group, and the metal-binding imidazole side chain. Because of LPA's involvement in pathological processes, regulation of its formation by ATX may give insight into possible novel therapeutic approaches.

  15. The effects of S(-)-, R(+)-, and racemic bupivacaine on lysophosphatidate-induced priming of human neutrophils

    NARCIS (Netherlands)

    Hollmann, Markus W.; Kurz, Katrin; Herroeder, Susanne; Struemper, Danja; Hahnenkamp, Klaus; Berkelmans, Noud S.; den Bakker, Christel G.; Durieux, Marcel E.

    2003-01-01

    Local anesthetics modulate inflammatory responses and may therefore be potentially useful in mitigating perioperative inflammatory injury. The inflammatory modulating effects of S(-)-bupivacaine are not known. Therefore, we compared the effects of S(-)-bupivacaine, R(+)-bupivacaine, and racemic

  16. A liver-specific defect of Acyl-CoA degradation produces hyperammonemia, hypoglycemia and a distinct hepatic Acyl-CoA pattern.

    Directory of Open Access Journals (Sweden)

    Nicolas Gauthier

    Full Text Available Most conditions detected by expanded newborn screening result from deficiency of one of the enzymes that degrade acyl-coenzyme A (CoA esters in mitochondria. The role of acyl-CoAs in the pathophysiology of these disorders is poorly understood, in part because CoA esters are intracellular and samples are not generally available from human patients. We created a mouse model of one such condition, deficiency of 3-hydroxy-3-methylglutaryl-CoA lyase (HL, in liver (HLLKO mice. HL catalyses a reaction of ketone body synthesis and of leucine degradation. Chronic HL deficiency and acute crises each produced distinct abnormal liver acyl-CoA patterns, which would not be predictable from levels of urine organic acids and plasma acylcarnitines. In HLLKO hepatocytes, ketogenesis was undetectable. Carboxylation of [2-(14C] pyruvate diminished following incubation of HLLKO hepatocytes with the leucine metabolite 2-ketoisocaproate (KIC. HLLKO mice also had suppression of the normal hyperglycemic response to a systemic pyruvate load, a measure of gluconeogenesis. Hyperammonemia and hypoglycemia, cardinal features of many inborn errors of acyl-CoA metabolism, occurred spontaneously in some HLLKO mice and were inducible by administering KIC. KIC loading also increased levels of several leucine-related acyl-CoAs and reduced acetyl-CoA levels. Ultrastructurally, hepatocyte mitochondria of KIC-treated HLLKO mice show marked swelling. KIC-induced hyperammonemia improved following administration of carglumate (N-carbamyl-L-glutamic acid, which substitutes for the product of an acetyl-CoA-dependent reaction essential for urea cycle function, demonstrating an acyl-CoA-related mechanism for this complication.

  17. E1A-dependent trans-activation of the human MYC promoter is mediated by the E2F factor

    International Nuclear Information System (INIS)

    Hiebert, S.W.; Lipp, M.; Nevins, J.R.

    1989-01-01

    E2F is a cellular transcription factor that binds to two sites in the adenovirus E2 promoter. Previous experiments have implicated E2F in the E1A-dependent transactivation of the E2 gene since levels of active E2F increase markedly during adenovirus infection in parallel with the increase in E2 transcription, and an E2F binding site can confer E1A inducibility to a heterologous promoter. Here the authors show that E2F binds to two sequence elements within the P2 promoter of the human MYC gene which are within a region that is critical for promoter activity. The MYC promoter can be trans-activated in an E1A-dependent manner and site-directed mutagenesis demonstrates that these E2F elements are essential for trans-activation. Finally, they also find that adenovirus infection of quiescent cells results in a stimulation of the endogenous MYC gene. They conclude that the activation of the E2F factor, which is likely responsible for the activation of viral E2 transcription, is also responsible for the E1A-dependent induction of MYC transcription

  18. Definition of a Dependent Child

    CERN Multimedia

    Human Resources Department

    2005-01-01

    The Department of Human Resources wishes to remind members of the personnel that, under the provisions of § 6 of Administrative Circular No. 5 “Dependent child”, in the case of a child over 18 years of age the status of dependent child comes to an end once a course of studies is completed. Consequently, the payment of the dependent child allowance and the child's membership of the CERN Health Insurance Scheme terminate with effect from the last day of the month in which the course of study concerned ends. In this connection, members of the personnel are reminded that children who are no longer dependent according to the Staff Rules and Regulations and who are less than 26 years of age can nevertheless opt for membership of the normal health insurance under the terms and conditions laid down in the CERN Health Insurance Rules. The Department of Human Resources also wishes to remind members of the personnel that, pursuant to Article R IV 1.17 of the Staff Regulations, a member of the personnel is requ...

  19. Creating Directed Double-strand Breaks with the Ref Protein: A Novel Rec A-Dependent Nuclease from Bacteriophage P1

    Energy Technology Data Exchange (ETDEWEB)

    Gruenig, Marielle C.; Lu, Duo; Won, Sang Joon; Dulberger, Charles L.; Manlick, Angela J.; Keck, James L.; Cox, Michael M. (UW)

    2012-03-16

    The bacteriophage P1-encoded Ref protein enhances RecA-dependent recombination in vivo by an unknown mechanism. We demonstrate that Ref is a new type of enzyme; that is, a RecA-dependent nuclease. Ref binds to ss- and dsDNA but does not cleave any DNA substrate until RecA protein and ATP are added to form RecA nucleoprotein filaments. Ref cleaves only where RecA protein is bound. RecA functions as a co-nuclease in the Ref/RecA system. Ref nuclease activity can be limited to the targeted strands of short RecA-containing D-loops. The result is a uniquely programmable endonuclease activity, producing targeted double-strand breaks at any chosen DNA sequence in an oligonucleotide-directed fashion. We present evidence indicating that cleavage occurs in the RecA filament groove. The structure of the Ref protein has been determined to 1.4 {angstrom} resolution. The core structure, consisting of residues 77-186, consists of a central 2-stranded {beta}-hairpin that is sandwiched between several {alpha}-helical and extended loop elements. The N-terminal 76 amino acid residues are disordered; this flexible region is required for optimal activity. The overall structure of Ref, including several putative active site histidine residues, defines a new subclass of HNH-family nucleases. We propose that enhancement of recombination by Ref reflects the introduction of directed, recombinogenic double-strand breaks.

  20. A Dependence Study of $\\Xi^{*0}$ and $\\bar{\\Xi}^{*0}$ in 250 GeV/c $\\pi^-$. $K^-$ -nucleon Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Seixas de Rezende, Fabio Antonio; /Rio de Janeiro, CBPF

    2005-04-01

    A direct measurement of the mass number (A) dependence of the production of the hyperon {Xi}*{sup 0} and its opposite {bar {Xi}}*{sup 0} in {pi}{sup -}, K{sup -} beam-nucleon interactions at 250 GeV/c is reported. The data derive from the experiment E769 at Fermilab. The results were obtained for different targets: Be, Al, Cu and W. It was observed the data are found to be well described by the parametrization {sigma}{sub A} = {sigma}{sub 0}A{sup {alpha}}, {alpha} being calculated for different beams. The results obtained are compared with those results of E769 experiment. The results shown here are preliminary.

  1. Accumulation of cyclin B1 requires E2F and cyclin-A-dependent rearrangement of the anaphase-promoting complex

    DEFF Research Database (Denmark)

    Lukas, C; Sørensen, Claus Storgaard; Kramer, E

    1999-01-01

    In mammalian somatic-cell cycles, progression through the G1-phase restriction point and initiation of DNA replication are controlled by the ability of the retinoblastoma tumour-suppressor protein (pRb) family to regulate the E2F/DP transcription factors. Continuing transcription of E2F target...... in the timely accumulation of cyclin B1 and the coordination of cell-cycle progression during the post-restriction point period....... remains unknown. Here, using an in vivo assay to measure protein stability in real time during the cell cycle, we show that repression of E2F activity or inhibition of cyclin-A-dependent kinase in S phase triggers the destruction of cyclin B1 through the re-assembly of APC, the ubiquitin ligase...

  2. Isolimonic acid interferes with Escherichia coli O157:H7 biofilm and TTSS in QseBC and QseA dependent fashion

    Science.gov (United States)

    2012-01-01

    Background E. coli O157:H7 (EHEC) is an important human pathogen. The antibiotic treatment of EHEC reportedly results in release of Shiga toxin and is therefore discouraged. Consequently, alternative preventive or therapeutic strategies for EHEC are required. The objective of the current study was to investigate the effect of citrus limonoids on cell-cell signaling, biofilm formation and type III secretion system in EHEC. Results Isolimonic acid and ichangin were the most potent inhibitors of EHEC biofilm (IC25=19.7 and 28.3 μM, respectively) and adhesion to Caco-2 cells. The qPCR analysis revealed that isolimonic acid and ichangin repressed LEE encoded genes by ≈3 to 12 fold. In addition, flhDC was repressed by the two limonoids (≈3 to 7 fold). Further studies suggested that isolimonic acid interferes with AI-3/epinephrine activated cell-cell signaling pathway. Loss of biofilm inhibitory activity of isolimonic acid in ΔqseBC mutant, which could be restored upon complementation, suggested a dependence on functional QseBC. Additionally, overexpression of qseBC in wild type EHEC abated the inhibitory effect of isolimonic acid. Furthermore, the isolimonic acid failed to differentially regulate ler in ΔqseA mutant, while plasmid borne expression of qseA in ΔqseA background restored the repressive effect of isolimonic acid. Conclusions Altogether, results of study seem to suggest that isolimonic acid and ichangin are potent inhibitors of EHEC biofilm and TTSS. Furthermore, isolimonic acid appears to interfere with AI-3/epinephrine pathway in QseBC and QseA dependent fashion. PMID:23153211

  3. A Precision Measurement of the A-Dependence of Dimuon Production in Proton - Nucleus Collisions at 800 GeV/C

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ming-jer [Case Western Reserve U.

    1991-05-01

    Precision measurements of the A-dependence of the reaction $p + A. \\to \\mu^+ \\mu^- + X$ at 800 GeV /care reported in this thesis. Data were taken at Fermilab (E772) using a modified version of the large dimuon spectrometer in the ) Meson-East beamline. A total of 6 x $10^5$ muon pairs were recorded for targets of D, C, Ca, Fe, and W. The kinematic region spanned by the data corresponds to a dimuon invariant mass of $3 \\le M_{\\mu^+ + \\mu^-}$ 14 GeV, a Feynman-x of $-0.1 \\le x_F \\le 0.7$ and a target parton momentum fraction of $0.03 \\le x_2 \\le 0.30$. Accurate relative target normalizations were achieved by careful monitoring of beam intensity and position, cyclic interchanges of targets; maintaining nearly 100% electronic lifetime, and by use of precisely fabricated targets. The systematic errors in the relative yields are less than 2% for all targets. Results are presented on the ratios of cross sections for nuclear targets relative to deuterium for the Drell-Y an process and for the production of the $J/\\upsilon$ , $\\psi$' , and $\\Upsilon$ quarkonia. These ratios are presented as functions of variables $P_{\\tau}$ and $X_F$ , and versus $x_1$ and $x_2$ for the Drell-Yan process. Nuclear depletion at low-$x_2$ is observed for the first time in the Drell-Yan process. No nuclear enhancement of the antiquark distribution is observed in the region $x_2 \\ge 0.1$ . The data give tight constraints on models developed to explain nuclear medium effects in deep inelastic lepton scattering (EMC effect). Specifically, published models that have postulated a pion excess and 6-quark clusters are ruled out. The A-dependent behaviors on $X_F$ and $P_{\\tau}$ for $J/\\psi$ , $\\psi$' , and $\\upsilon$ production are also reported and compared with previous experiments. Substantial nuclear depletions are observed in both the $X_F$ and $P_{\\tau}$ dependence. These depletions increase with increasing $X_F$ , and decrease with increasing $P_{\\tau}$ .

  4. Brief Report: Interleukin-17A-Dependent Asymmetric Stem Cell Divisions Are Increased in Human Psoriasis: A Mechanism Underlying Benign Hyperproliferation.

    Science.gov (United States)

    Charruyer, Alexandra; Fong, Stephen; Vitcov, Giselle G; Sklar, Samuel; Tabernik, Leah; Taneja, Monica; Caputo, Melinda; Soeung, Catherine; Yue, Lili; Uchida, Yoshi; Arron, Sarah T; Horton, Karen M; Foster, Robert D; Sano, Shigetoshi; North, Jeffrey P; Ghadially, Ruby

    2017-08-01

    The balance between asymmetric and symmetric stem cell (SC) divisions is key to tissue homeostasis, and dysregulation of this balance has been shown in cancers. We hypothesized that the balance between asymmetric cell divisions (ACDs) and symmetric cell divisions (SCDs) would be dysregulated in the benign hyperproliferation of psoriasis. We found that, while SCDs were increased in squamous cell carcinoma (SCC) (human and murine), ACDs were increased in the benign hyperproliferation of psoriasis (human and murine). Furthermore, while sonic hedgehog (linked to human cancer) and pifithrinα (p53 inhibitor) promoted SCDs, interleukin (IL)-1α and amphiregulin (associated with benign epidermal hyperproliferation) promoted ACDs. While there was dysregulation of the ACD:SCD ratio, no change in SC frequency was detected in epidermis from psoriasis patients, or in human keratinocytes treated with IL-1α or amphiregulin. We investigated the mechanism whereby immune alterations of psoriasis result in ACDs. IL17 inhibitors are effective new therapies for psoriasis. We found that IL17A increased ACDs in human keratinocytes. Additionally, studies in the imiquimod-induced psoriasis-like mouse model revealed that ACDs in psoriasis are IL17A-dependent. In summary, our studies suggest an association between benign hyperproliferation and increased ACDs. This work begins to elucidate the mechanisms by which immune alteration can induce keratinocyte hyperproliferation. Altogether, this work affirms that a finely tuned balance of ACDs and SCDs is important and that manipulating this balance may constitute an effective treatment strategy for hyperproliferative diseases. Stem Cells 2017;35:2001-2007. © 2017 AlphaMed Press.

  5. Novel magnetic resonance imaging findings in a patient with short chain acyl CoA dehydrogenase deficiency.

    Science.gov (United States)

    Chiplunkar, Shwetha; Bindu, Parayil Sankaran; Nagappa, Madhu; Panikulam, Bobby Baby; Arvinda, Hanumanthapura R; Govindaraj, Periyasamy; Srinivas Bharath, M M; Gayathri, Narayanappa; Jessiena Ponmalar, J N; Mathuranath, Pavagada S; Sinha, Sanjib; Taly, Arun B

    2017-08-01

    Reports on magnetic resonance imaging findings in patients with short chain acyl -Coenzyme A dehydrogenase (SCAD) deficiency, an autosomal recessive disorder caused by mutations in the acyl-Coenzyme A dehydrogenase (ACADS), are limited. Many asymptomatic carriers of ACAD variants have also been described necessitating careful evaluation of clinical and biochemical findings for an accurate diagnosis. Here we report a an infant with short chain acyl -Coenzyme A dehydrogenase (SCAD) deficiency diagnosed based on the characteristic biochemical findings and confirmed by genetic testing. He presented with refractory seizures and neuro regression at 4 months of age. His metabolic work up revealed elevated butyryl carnitine in plasma and ethyl malonic acid in urine. Magnetic resonance imaging of the brain showed cortical and basal ganglia signal changes with cortical swelling. Serial scans showed progression of the lesions resulting in cystic leukomalacia with brain atrophy. Exome sequencing revealed a novel homozygous nonsense variation, c.1146C > G (p.Y382Ter) in exon ten of ACADS which was further validated by Sanger sequencing. Both parents were heterozygous carriers. Follow up at 15 months showed gross psychomotor retardation and refractory seizures despite being on optimal doses of anti-epileptic medications, carnitine and multivitamin supplementation. This report expands the phenotypic and genotypic spectrum of SCAD deficiency.

  6. Lysophosphatidic acid inhibition of the accumulation of Pseudomonas aeruginosa PAO1 alginate, pyoverdin, elastase and LasA

    DEFF Research Database (Denmark)

    Laux, D.C.; Corson, J.M.; Givskov, Michael Christian

    2002-01-01

    The pathogenesis of Pseudomonas aeruginosa is at least partially attributable to its ability to synthesize and secrete the siderophore pyoverdin and the two zinc metal loproteases elastase and LasA, and its ability to form biofilms in which bacterial cells are embedded in an alginate matrix....... In the present study, a lysophospholipid, 1-paimitoyl-2-hydroxy-sn-glycero-3-phosphate [also called monopalmitoylphosphatidic acid (MPPA)], which accumulates in inflammatory exudates, was shown to inhibit the extracellular accumulation of P. aeruginosa PAO1 alginate, elastase, LasA protease and the siderophore...

  7. Dual Action of Lysophosphatidate-Functionalised Titanium: Interactions with Human (MG63) Osteoblasts and Methicillin Resistant Staphylococcus aureus

    DEFF Research Database (Denmark)

    Skindersø, Mette Elena; Krogfelt, Karen Angeliki; Blom, Ashley

    2015-01-01

    Titanium (Ti) is a widely used material for surgical implants; total joint replacements (TJRs), screws and plates for fixing bones and dental implants are forged from Ti. Whilst Ti integrates well into host tissue approximately 10% of TJRs will fail in the lifetime of the patient through a proces...... of Staphylococcus aureus, a bacterium often associated with implant failures through sepsis. Collectively we provide evidence for the fabrication of a dual-action Ti surface finish, a highly desirable feature towards the development of next-generation implantable devices....... known as aseptic loosening. These failures necessitate revision arthroplasties which are more complicated and costly than the initial procedure. Finding ways of enhancing early (osseo)integration of TJRs is therefore highly desirable and continues to represent a research priority in current biomaterial...

  8. A measurement of the A-dependence of the J/PSI cross section by comparing data on hydrogen and tungsten targets at 39.5 GeV/c

    International Nuclear Information System (INIS)

    Corden, M.J.; Dowell, J.D.; Garvey, J.; Homer, R.J.; Jobes, M.; Kenyon, I.R.; McMahon, T.J.; Owen, R.C.; Sumorok, K.C.T.; Vallance, R.J.

    1982-01-01

    J/PSI production on hydrogen and tungsten targets has been compared at 39.5 GeV/c and the variation of the A-dependence of the J/PSI cross section as a function of psub(t) 2 and xsub(F) has been measured. The A-dependence parameter, α, rises with increasing p 2 2 and falls with increasing xsub(F). Both effects are shown not to be due to the Fermi motion of nucleons in the tungsten nucleus. (orig.)

  9. Photosynthetic Electron Transport Involved in PxcA-Dependent Proton Extrusion in Synechocystis sp. Strain PCC6803: Effect of pxcA Inactivation on CO2, HCO3−, and NO3− Uptake

    OpenAIRE

    Sonoda, Masatoshi; Katoh, Hirokazu; Vermaas, Wim; Schmetterer, George; Ogawa, Teruo

    1998-01-01

    The product of pxcA (formerly known as cotA) is involved in light-induced Na+-dependent proton extrusion. In the presence of 2,5-dimethyl-p-benzoquinone, net proton extrusion by Synechocystis sp. strain PCC6803 ceased after 1 min of illumination and a postillumination influx of protons was observed, suggesting that the PxcA-dependent, light-dependent proton extrusion equilibrates with a light-independent influx of protons. A photosystem I (PS I) deletion mutant extruded a large number of prot...

  10. A Influência da Confiança, Dependência e Comprometimento na Orientação de Longo Prazo de Varejistas para com os Fabricantes Líderes do Mercado de Bebidas

    Directory of Open Access Journals (Sweden)

    Ivan Lapuente Garrido

    2013-09-01

    Full Text Available O objetivo principal deste estudo é analisar como a confiança, o comprometimento e a dependência influenciam a orientação de longo prazo de varejistas para com o relacionamento com as empresas fabricantes de cervejas e refrigerantes líderes no mercado nacional. Para atingir o objetivo proposto, fizeram-se necessárias duas etapas de pesquisa. Na primeira etapa de cunho exploratório, foram realizadas entrevistas em profundidade com varejistas que possuíam relacionamento comercial com as empresas líderes do mercado nacional de cervejas e refrigerantes; esta etapa possibilitou aprofundamento sobre o campo de estudo e adequação de escalas aplicadas a segunda etapa de pesquisa. Na segunda etapa de pesquisa, por meio de questionário composto por questões fechadas, 299 varejistas avaliaram seu relacionamento com os fabricantes líderes de mercado. Utilizando-se de regressão múltipla, os resultados indicam que: (a a dependência dos varejistas influencia positivamente o comprometimento para com os fabricantes, (b a confiança influencia positivamente a orientação de longo prazo dos varejistas para com os fabricantes e, (c o comprometimento influencia positivamente a orientação de longo prazo dos varejistas para com os fabricantes. As hipóteses que consideravam a relação entre confiança e comprometimento e entre dependência e orientação de longo prazo não obtiveram significância estatística. DOI: 10.5585/remark.v12i3.2328

  11. Micro method for determination of nonesterified fatty acid in whole blood obtained by fingertip puncture

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Munk, Jens; Gaster, Michael

    2006-01-01

    -related disorders. In the current study, we developed a sensitive and reproducible micro method for quantification of NEFA in less than 10 microl whole blood. The method involves only two steps: (i) conversion of NEFA to fatty acid acyl-coenzyme A (acyl-CoA) esters using an acyl-CoA synthetase and (ii......Diagnostic tools for early identification of subjects at high risk for type 2 diabetes and other obesity-related disorders are important in prevention of these diseases. Nonesterified fatty acids (NEFAs) have been suggested to serve as a prediagnostic marker of diabetes and obesity...

  12. The Effect of Lysophosphatidic Acid during In Vitro Maturation of Bovine Oocytes: Embryonic Development and mRNA Abundances of Genes Involved in Apoptosis and Oocyte Competence

    Directory of Open Access Journals (Sweden)

    Dorota Boruszewska

    2014-01-01

    Full Text Available In the present study we examined whether LPA can be synthesized and act during in vitro maturation of bovine cumulus oocyte complexes (COCs. We found transcription of genes coding for enzymes of LPA synthesis pathway (ATX and PLA2 and of LPA receptors (LPAR 1–4 in bovine oocytes and cumulus cells, following in vitro maturation. COCs were matured in vitro in presence or absence of LPA (10−5 M for 24 h. Supplementation of maturation medium with LPA increased mRNA abundance of FST and GDF9 in oocytes and decreased mRNA abundance of CTSs in cumulus cells. Additionally, oocytes stimulated with LPA had higher transcription levels of BCL2 and lower transcription levels of BAX resulting in the significantly lower BAX/BCL2 ratio. Blastocyst rates on day 7 were similar in the control and the LPA-stimulated COCs. Our study demonstrates for the first time that bovine COCs are a potential source and target of LPA action. We postulate that LPA exerts an autocrine and/or paracrine signaling, through several LPARs, between the oocyte and cumulus cells. LPA supplementation of maturation medium improves COC quality, and although this was not translated into an enhanced in vitro development until the blastocyst stage, improved oocyte competence may be relevant for subsequent in vivo survival.

  13. Lysophosphatidic Acid Acyltransferase from Coconut Endosperm Mediates the Insertion of Laurate at the sn-2 Position of Triacylglycerols in Lauric Rapeseed Oil and Can Increase Total Laurate Levels

    Science.gov (United States)

    Knutzon, Deborah S.; Hayes, Thomas R.; Wyrick, Annette; Xiong, Hui; Maelor Davies, H.; Voelker, Toni A.

    1999-01-01

    Expression of a California bay laurel (Umbellularia californica) 12:0-acyl-carrier protein thioesterase, bay thioesterase (BTE), in developing seeds of oilseed rape (Brassica napus) led to the production of oils containing up to 50% laurate. In these BTE oils, laurate is found almost exclusively at the sn-1 and sn-3 positions of the triacylglycerols (T.A. Voelker, T.R. Hayes, A.C. Cranmer, H.M. Davies [1996] Plant J 9: 229–241). Coexpression of a coconut (Cocos nucifera) 12:0-coenzyme A-preferring lysophosphatitic acid acyltransferase (D.S. Knutzon, K.D. Lardizabal, J.S. Nelsen, J.L. Bleibaum, H.M. Davies, J.G. Metz [1995] Plant Physiol 109: 999–1006) in BTE oilseed rape seeds facilitates efficient laurate deposition at the sn-2 position, resulting in the acccumulation of trilaurin. The introduction of the coconut protein into BTE oilseed rape lines with laurate above 50 mol % further increases total laurate levels. PMID:10398708

  14. Detection of Serum Lysophosphatidic Acids Using Affinity Binding and Surface Enhanced Laser Deorption/Ionization (SELDI) Time of Flight Mass Spectrometry

    Science.gov (United States)

    2006-04-01

    structurally distant from the Edg family. J. Biol. Chem. 30 Apr 2003 [epub ahead of print]. Identification of the fourth LPA receptor, LPA4. 65. Contos, J. J...Ishii S, Shimizu T. 2003. Identification of p2y9/ GPR23 as a novel G protein-coupled receptor for lysopho- sphatidic acid, structurally distant from...coupled receptors requires metallopro- teinase cleavage of proHB-EGF. Nature 402:884–888. Pustilnik TB, Estrella V, Wiener JR, Mao M, Eder A, Watt MA

  15. The nicotine dependence associated with alcohol use and other psychoactive substance A dependência da nicotina associada ao uso de álcool e outras substâncias psicoativas

    Directory of Open Access Journals (Sweden)

    Rafaela Serra Bacchi

    2008-10-01

    Full Text Available To examine an association between nicotine dependence with alcohol, other psychoactive use, and depressive disorder. Smokers were recruited from Centro de Referência de Abordagem e Tratamento do Tabagismo at the Hospital das Clínicas da Universidade Estadual de Londrina (AHC/ UEL. All subjects were informed and gave then written consent for the research as approved by the Ethics Research Committee of Universidade Estadual de Londrina. The measures used were: structured questionnaire, alcohol, smoking, and psychoactive substance involvement screening test (ASSIST v 3.0, the Fagerström test for Nicotine Dependence (FTND, and the Diagnostic Interview for Research on Depressive disorder of the World Health Organization. Smokers presented the following socio-demographic characteristics: prevalence of the female sex and mean age of 47 years old with capacity for domestic activities and work. The mean age of onset of cigarette use for smokers was 16 years old. Fagerström’s test presented a medium punctuation of 6, so much for users of substances psicoativas, as for the ones that they don’t use them. Relationship between serious depression and the of psychoactive substances use was relevant for the research. This study evidenced an association among the use of the tobacco and other psychoactive substances, and depressive disorder. The health professional in smoking cessation intervention would be to identify subgroups of adult smokers, associated with depression, psychoactive substance use, and promote an intervention in both comorbidities and larger effectiveness of the smoking cessation. Analisar a associação entre a dependência de nicotina com o uso de álcool, outras substâncias psicoativas e transtorno depressivo. Os tabagistas foram recrutados a partir do Centro de Referência de Abordagem e Tratamento do Tabagismo no Hospital de Clínicas da Universidade Estadual de Londrina (AHC/UEL. Todos os participantes foram informados e

  16. Characterization of the mycobacterial acyl-CoA carboxylase holo complexes reveals their functional expansion into amino acid catabolism.

    Directory of Open Access Journals (Sweden)

    Matthias T Ehebauer

    2015-02-01

    Full Text Available Biotin-mediated carboxylation of short-chain fatty acid coenzyme A esters is a key step in lipid biosynthesis that is carried out by multienzyme complexes to extend fatty acids by one methylene group. Pathogenic mycobacteria have an unusually high redundancy of carboxyltransferase genes and biotin carboxylase genes, creating multiple combinations of protein/protein complexes of unknown overall composition and functional readout. By combining pull-down assays with mass spectrometry, we identified nine binary protein/protein interactions and four validated holo acyl-coenzyme A carboxylase complexes. We investigated one of these--the AccD1-AccA1 complex from Mycobacterium tuberculosis with hitherto unknown physiological function. Using genetics, metabolomics and biochemistry we found that this complex is involved in branched amino-acid catabolism with methylcrotonyl coenzyme A as the substrate. We then determined its overall architecture by electron microscopy and found it to be a four-layered dodecameric arrangement that matches the overall dimensions of a distantly related methylcrotonyl coenzyme A holo complex. Our data argue in favor of distinct structural requirements for biotin-mediated γ-carboxylation of α-β unsaturated acid esters and will advance the categorization of acyl-coenzyme A carboxylase complexes. Knowledge about the underlying structural/functional relationships will be crucial to make the target category amenable for future biomedical applications.

  17. Multisite Promiscuity in the Processing of Endogenous Substrates By Human Carboxylesterase 1

    Energy Technology Data Exchange (ETDEWEB)

    Bencharit, S.; Edwards, C.C.; Morton, C.L.; Howard-Williams, E.L.; Kuhn, P.; Potter, P.M.; Redinbo, M.R.; /North Carolina U. /St. Jude Children' s Hosp., Memphis /SLAC,

    2007-01-16

    Human carboxylesterase 1 (hCE1) is a drug and endobiotic-processing serine hydrolase that exhibits relatively broad substrate specificity. It has been implicated in a variety of endogenous cholesterol metabolism pathways including the following apparently disparate reactions: cholesterol ester hydrolysis (CEH), fatty acyl Coenzyme A hydrolysis (FACoAH), acyl-Coenzyme A:cholesterol acyltransfer (ACAT), and fatty acyl ethyl ester synthesis (FAEES). The structural basis for the ability of hCE1 to perform these catalytic actions involving large substrates and products has remained unclear. Here we present four crystal structures of the hCE1 glycoprotein in complexes with the following endogenous substrates or substrate analogues: Coenzyme A, the fatty acid palmitate, and the bile acids cholate and taurocholate. While the active site of hCE1 was known to be promiscuous and capable of interacting with a variety of chemically distinct ligands, these structures reveal that the enzyme contains two additional ligand-binding sites and that each site also exhibits relatively non-specific ligand-binding properties. Using this multisite promiscuity, hCE1 appears structurally capable of assembling several catalytic events depending, apparently, on the physiological state of the cellular environment. These results expand our understanding of enzyme promiscuity and indicate that, in the case of hCE1, multiple non-specific sites are employed to perform distinct catalytic actions.

  18. [Rhabdomyolysis - may it be a metabolic myopathy? Case report and diagnostic algorithm].

    Science.gov (United States)

    Sebők, Ágnes; Pál, Endre; Molnár, Gergő Attila; Wittmann, István; Berenténé Bene, Judit; Melegh, Béla; Komoly, Sámuel; Hidvégi, Tibor; Balogh, Lídia; Szabó, Attila; Zsidegh, Petra

    2017-11-01

    We report the case of a 46-year-old female patient with recurrent rhabdomyolysis. In the background of her metabolic myopathy an inherited metabolic disorder of the fatty acid oxidation, very long-chain acyl-coenzyme A-dehydrogenase deficiency was diagnosed. The diagnosis was based on abnormal acyl-carnitine- and urine organic-acid profile in addition to low residual enzyme activity, and was confirmed by genetic testing. After introduction of dietotherapy metabolic crisis necessitating hospital admission has not occurred neither have fixed myopathic changes developed. We present here the differential diagnosis of rhabdomyolysis and exertional muscle complaints, with the metabolic myopathies in focus. The main features of fatty acid oxidation disorders are highlighted, acute and chronic managements of very long-chain acyl-coenzyme A-dehydrogenase deficiency are discussed. Metabolic myopathies respond well to treatment, so good quality of life can be achieved. However, especially in fatty acid oxidation disorders, a metabolic crisis may develop quickly and can be fatal, albeit rarely. Some of these disorders can be identified by newborn screening, but occasionally the symptoms may manifest only in adulthood. With the presentation of this case we would like to point out that in the differential diagnosis of recurrent rhabdomyolysis inherited metabolic disorders should be considered regardless of the patient's age. Orv Hetil. 2017; 158(46): 1873-1882.

  19. Quantitative liquid chromatography coupled with tandem mass spectrometry analysis of urinary acylglycines: application to the diagnosis of inborn errors of metabolism.

    Science.gov (United States)

    Ombrone, Daniela; Salvatore, Francesco; Ruoppolo, Margherita

    2011-10-01

    The analysis of urinary acylglycines is an important biochemical tool for the diagnosis of many organic acidemias and mitochondrial fatty acid β-oxidation defects. A new rapid analytical method has been developed for quantification of acylglycines in urine by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The method requires a simple sample preparation avoiding derivatization. It has high sensitivity, specificity, and throughput capability, and it requires minimal instrument maintenance. The use of chromatographic separation allows us to identify and quantify isomeric compounds that cannot be solved by appropriate multiple reaction monitoring (MRM) transitions. Urinary concentrations of the different acylglycines were determined using deuterated internal standards. The reference interval for the various metabolites was established using 120 healthy controls. The diagnostic usefulness of the method was demonstrated in three patients with propionic acidemia (PA), one patient with isovaleric acidemia (IVA), two patients with beta ketothiolase deficiency (BKTD), one patient with short branched chain amino acid deficiency (SBCAD), four patients with medium chain acyl-coenzyme A dehydrogenase deficiency (MCADD), one patient with isobutyryl-coenzyme A dehydrogenase deficiency (IBDHD), and one patient with multiple acyl-coenzyme A dehydrogenase deficiency (MADD). Copyright © 2011 Elsevier Inc. All rights reserved.

  20. A dependence modelling study of extreme rainfall in Madeira Island

    Science.gov (United States)

    Gouveia-Reis, Délia; Guerreiro Lopes, Luiz; Mendonça, Sandra

    2016-08-01

    The dependence between variables plays a central role in multivariate extremes. In this paper, spatial dependence of Madeira Island's rainfall data is addressed within an extreme value copula approach through an analysis of maximum annual data. The impact of altitude, slope orientation, distance between rain gauge stations and distance from the stations to the sea are investigated for two different periods of time. The results obtained highlight the influence of the island's complex topography on the spatial distribution of extreme rainfall in Madeira Island.

  1. Care plan for the patient with a dependent personality disorder

    Directory of Open Access Journals (Sweden)

    Ana María Ruiz Galán

    2010-11-01

    Full Text Available Personality is unique for each individual and can be defined as the dynamic collection of characteristics relative to emotions, thought and behaviour.Personality trout’s only mean a Personality Disorder (PD when they are inflexible and maladjusted and cause notable functional deterioration or uneasiness.According to Bermudez personality is “the enduring organization of structural and functional features, innate and acquired under the special conditions of each one’s development that shape the particular and specific collection of behaviour to face different situations”.According to the Diagnostic a Statistical Manual of Mental Disorders (DSM-IV, a Personality Disorder is “an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the person’s culture is pervasive and an inflexible, is stable over time and leads to distress or impairment. The onset of these patterns of behaviour is the beginning of the adulthood and, in rare instances, early adolescence”.There are several types of Personality Disorders (paranoid, schizoid, borderline, antisocial, dependent…. Dependent Personality Disorder is one of the most frequent in the Mental Health Services.People who suffer from this disorder are unable to take a decision by themselves because they don’t have confidence in themselves. They need a lot of social support and affection until the point of deny their individuality by subordinating their desires to other person’s desires and permitting these persons to manage their lives. Maybe they feel desolated by separation and loss and can support any situation, even maltreatment to keep a relationship.As we a deduce this diagnosis is sensible to cultural influences. This work aims to elaborate an standarized plan of cares for the patient with Dependent Personality Disorder by using nursing Diagnosis of NANDA II, Outcomes Criteria (NOC and Interventions Criteria (NIC.

  2. The integrated periodogram of a dependent extremal event sequence

    OpenAIRE

    Mikosch, Thomas; Zhao, Yuwei

    2015-01-01

    We investigate the asymptotic properties of the integrated periodogram calculated from a sequence of indicator functions of dependent extremal events. An event in Euclidean space is extreme if it occurs far away from the origin. We use a regular variation condition on the underlying stationary sequence to make these notions precise. Our main result is a functional central limit theorem for the integrated periodogram of the indicator functions of dependent extremal events. The limiting process...

  3. Design of a dependable Interlock System for linear colliders

    CERN Document Server

    Nouvel, Patrice

    For high energy accelerators, the interlock system is a key part of the machine protection. The interlock principle is to inhibit the beam either on failure of critical equipment and/or on low beam quality evaluation. The dependability of such a system is the most critical parameter. This thesis presents the design of an dependable interlock system for linear collider with an application to the CLIC (Compact Linear Collider) project. This design process is based on the IEEE 1220 standard and is is divided in four steps. First, the specifications are established, with a focus on the dependability, more precisely the reliability and the availability of the system. The second step is the design proposal based on a functional analysis, the CLIC and interfaced systems architecture. Third, the feasibility study is performed, applying the concepts in an accelerator facility. Finally, the last step is the hardware verification. Its aim is to prove that the proposed design is able to reach the requirements.

  4. A-Dependence of Photoproduced Jets and Comparison with Hadroproduction

    Energy Technology Data Exchange (ETDEWEB)

    Naples, Donna Lynne [Maryland U.

    1993-01-01

    Fermilab experiment E683 studied photoproduction of jets produced with a high energy real photon beam incident on nuclear targets. Data were collected with a segmented large acceptance calorimeter. The photon beam, which ranged in energy from 50-400 Ge V, is the highes~ in existence and allowed us to study jet production which was inaccessible to previous experiments at lower $\\sqrt{s}$. Jets with $P_t$ in the range 3-7 Ge V were reconstructed....

  5. Annotation of the Evaluative Language in a Dependency Treebank

    Directory of Open Access Journals (Sweden)

    Šindlerová Jana

    2017-12-01

    Full Text Available In the paper, we present our efforts to annotate evaluative language in the Prague Dependency Treebank 2.0. The project is a follow-up of the series of annotations of small plaintext corpora. It uses automatic identification of potentially evaluative nodes through mapping a Czech subjectivity lexicon to syntactically annotated data. These nodes are then manually checked by an annotator and either dismissed as standing in a non-evaluative context, or confirmed as evaluative. In the latter case, information about the polarity orientation, the source and target of evaluation is added by the annotator. The annotations unveiled several advantages and disadvantages of the chosen framework. The advantages involve more structured and easy-to-handle environment for the annotator, visibility of syntactic patterning of the evaluative state, effective solving of discontinuous structures or a new perspective on the influence of good/bad news. The disadvantages include little capability of treating cases with evaluation spread among more syntactically connected nodes at once, little capability of treating metaphorical expressions, or disregarding the effects of negation and intensification in the current scheme.

  6. The Integrated periodogram of a dependent extremal event sequence

    DEFF Research Database (Denmark)

    Mikosch, Thomas Valentin; Zhao, Yuwei

    2015-01-01

    We investigate the asymptotic properties of the integrated periodogram calculated from a sequence of indicator functions of dependent extremal events. An event in Euclidean space is extreme if it occurs far away from the origin. We use a regular variation condition on the underlying stationary...... sequence to make these notions precise. Our main result is a functional central limit theorem for the integrated periodogram of the indicator functions of dependent extremal events. The limiting process is a continuous Gaussian process whose covariance structure is in general unfamiliar, but in the i...

  7. A-dependence for the charmed meson production

    International Nuclear Information System (INIS)

    Alves, Gilvan Augusto.

    1992-03-01

    A report is presented of a recent direct measurement of the nucleon number (λ) dependence of the production cross sections for the charmed mesons D 0 and D + using π +- beams incident on a segmented target of Be, Al, Cu and W. The data derive from the experiment E769 - Hadroproduction of Charm - at Fermilab. The experimental apparatus is described together with the following analysis. Starting from a sample of ∼ 1500 D mesons in the range of O F A = σ O A α , with α = 0.99 ± 0.03. The X F dependence of α is examined and the results obtained are compared with those of other experiments and with theoretical expectations based on perturbative QCD and on an EMC like model of nuclear shadowing. (author). 85 refs, 61 figs, 22 tabs

  8. A dependência dos adolescentes ao mundo virtual

    Directory of Open Access Journals (Sweden)

    Bruna Goudinho Gonçalves

    2012-10-01

    Full Text Available http://dx.doi.org/10.5007/2178-4582.2012v46n1p165 O presente artigo trata-se de um estudo de campo do tipo exploratório, qualitativo realizado com 10 adolescentes voluntários (cinco do sexo feminino e cinco do sexo masculino de uma escola de Criciúma/SC. Para a coleta dos dados utilizou-se um questionário contendo dez perguntas, no qual procurou-se verificar a adicção dos adolescentes no mundo virtual e como este pode influenciar na vida social destes adolescentes. Salienta-se que é no período da adolescência que se constrói a identidade e a autonomia, como também ocorrem mudanças físicas e emocionais, mas com a utilização frequente da internet, pode ocorrer um comprometimento da interação social. Diante disso, concluise, a partir da análise dos dados que a internet potencializa a onipotência juvenil e se seguir neste contexto, vários adolescentes necessitarão de auxílio terapêutico. Este estudo contribui com esta temática tão importante e ainda pouco fundamentada.

  9. How a dependent's variable non-randomness affects taper equation ...

    African Journals Online (AJOL)

    In order to apply the least squares method in regression analysis, the values of the dependent variable Y should be random. In an example of regression analysis linear and nonlinear taper equations, which estimate the diameter of the tree dhi at any height of the tree hi, were compared. For each tree the diameter at the ...

  10. The Avalon Beowulf Cluster: A Dependable Tool for Scientific Simulation

    Science.gov (United States)

    Warren, Michael

    2000-03-01

    Avalon is a 140 processor Alpha/Linux Beowulf cluster constructed entirely from commodity personal computer technology and freely available software. Computational Physics simulations performed on Avalon resulted in the award of a 1998 Gordon Bell price/performance prize for significant achievement in parallel processing. Avalon ranked as the 113th fastest computer in the world on the November 1998 TOP500 list, obtaining a result of 48.6 Gigaflops on the parallel Linpack benchmark. The price of hardware and final assembly labor for Avalon totalled 313,000 dollars in the fall of 1998. Avalon currently provides over 15,000 node-hours of production computing time per week, split among about 10 production users. Obtaining an equivalent amount of computing through Los Alamos institutional sources would cost a minimicrons of 30,000 per week. The machine also supports code development for another 60 users. Significant simulations have been performed on Avalon in fields of astrophysics, molecular dynamics, nonlinear dynamics as well as other areas. The largest single simulation performed on Avalon computed a total of over 10^16 floating point operations. We will describe some of the applications which have obtained good performance on Avalon, and their characteristics. Our goal has been to provide dependable cycles for computational physics, and not to perform research into clustered computing systems. One of the main lessons learned from the Avalon project is that the details of the hardware are not nearly as important as the attitudes and expectations of the users and managers of the hardware.

  11. Regulation of very-long acyl chain ceramide synthesis by acyl-CoA-binding protein

    DEFF Research Database (Denmark)

    Ferreira, Natalia Santos; Engelsby, Hanne; Neess, Ditte

    2017-01-01

    and cardiovascular diseases, as well as neurological disorders. Here we show that acyl-coenzyme A-binding protein (ACBP) potently facilitates very-long acyl chain ceramide synthesis. ACBP increases the activity of ceramide synthase 2 (CerS2) by more than 2-fold and CerS3 activity by 7-fold. ACBP binds very...... of ACBP(-/-) mice, concomitant with a significant reduction in long- and very-long-chain ceramide levels. Importantly, we show that ACBP interacts with CerS2 and CerS3. Our data uncover a novel mode of regulation of very-long acyl chain ceramide synthesis by ACBP, which we anticipate is of crucial...

  12. Micro method for determination of nonesterified fatty acid in whole blood obtained by fingertip puncture

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Munk, Jens; Gaster, Michael

    2006-01-01

    -related disorders. In the current study, we developed a sensitive and reproducible micro method for quantification of NEFA in less than 10 microl whole blood. The method involves only two steps: (i) conversion of NEFA to fatty acid acyl-coenzyme A (acyl-CoA) esters using an acyl-CoA synthetase and (ii......Diagnostic tools for early identification of subjects at high risk for type 2 diabetes and other obesity-related disorders are important in prevention of these diseases. Nonesterified fatty acids (NEFAs) have been suggested to serve as a prediagnostic marker of diabetes and obesity...... exhibits high fluorescence emission yield with maximum at 490 nm in the presence of CoA when excited at 387 nm. The addition of palmitoyl-CoA to a CoA-saturated FACI-50 lowered fluorescence emission by eightfold. Ethanol extract from 1 microl whole blood was incubated with ATP, CoA, and FACI-50. Following...

  13. Analysis of Genes for Succinoyl Trehalose Lipid Production and Increasing Production in Rhodococcus sp. Strain SD-74

    Science.gov (United States)

    Inaba, Tomohiro; Tokumoto, Yuta; Miyazaki, Yusuke; Inoue, Naoyuki; Maseda, Hideaki; Nakajima-Kambe, Toshiaki; Uchiyama, Hiroo

    2013-01-01

    Succinoyl trehalose lipids (STLs) are promising glycolipid biosurfactants produced from n-alkanes that are secreted by Rhodococcus species bacteria. These compounds not only exhibit unique interfacial properties but also demonstrate versatile biochemical actions. In this study, three novel types of genes involved in the biosynthesis of STLs, including a putative acyl coenzyme A (acyl-CoA) transferase (tlsA), fructose-bisphosphate aldolase (fda), and alkane monooxygenase (alkB), were identified. The predicted functions of these genes indicate that alkane metabolism, sugar synthesis, and the addition of acyl groups are important for the biosynthesis of STLs. Based on these results, we propose a biosynthesis pathway for STLs from alkanes in Rhodococcus sp. strain SD-74. By overexpressing tlsA, we achieved a 2-fold increase in the production of STLs. This study advances our understanding of bacterial glycolipid production in Rhodococcus species. PMID:24038682

  14. Acyl-CoA metabolism and partitioning

    DEFF Research Database (Denmark)

    Grevengoed, Trisha J; Klett, Eric L; Coleman, Rosalind A

    2014-01-01

    expression patterns and subcellular locations. Their acyl-CoA products regulate metabolic enzymes and signaling pathways, become oxidized to provide cellular energy, and are incorporated into acylated proteins and complex lipids such as triacylglycerol, phospholipids, and cholesterol esters. Their differing......Long-chain fatty acyl-coenzyme As (CoAs) are critical regulatory molecules and metabolic intermediates. The initial step in their synthesis is the activation of fatty acids by one of 13 long-chain acyl-CoA synthetase isoforms. These isoforms are regulated independently and have different tissue...... metabolic fates are determined by a network of proteins that channel the acyl-CoAs toward or away from specific metabolic pathways and serve as the basis for partitioning. This review evaluates the evidence for acyl-CoA partitioning by reviewing experimental data on proteins that are believed to contribute...

  15. Green tea extract suppresses adiposity and affects the expression of lipid metabolism genes in diet-induced obese zebrafish

    Directory of Open Access Journals (Sweden)

    Hasumura Takahiro

    2012-08-01

    Full Text Available Abstract Background Visceral fat accumulation is one of the most important predictors of mortality in obese populations. Administration of green tea extract (GTE can reduce body fat and reduce the risk of obesity-related diseases in mammals. In this study, we investigated the effects and mechanisms of GTE on adiposity in diet-induced obese (DIO zebrafish. Methods Zebrafish at 3.5 to 4.5 months post-fertilization were allocated to four groups: non-DIO, DIO, DIO + 0.0025%GTE, and DIO + 0.0050%GTE. The non-DIO group was fed freshly hatched Artemia once daily (5 mg cysts/fish daily for 40 days. Zebrafish in the three DIO groups were fed freshly hatched Artemia three times daily (60 mg cysts/fish daily. Zebrafish in the DIO + 0.0025%GTE and DIO + 0.0050%GTE groups were exposed to GTE after the start of feeding three times daily for 40 days. Results Three-dimensional microcomputed tomography analysis showed that GTE exposure significantly decreased the volume of visceral but not subcutaneous fat tissue in DIO zebrafish. GTE exposure increased hepatic expression of the lipid catabolism genes ACOX1 (acyl-coenzyme A oxidase 1, palmitoyl, ACADM (acyl-coenzyme A dehydrogenase, c-4 to c-12 straight chain, and PPARA (peroxisome proliferator-activated receptor alpha. GTE exposure also significantly decreased the visceral fat expression of SOCS3 (suppressor of cytokine signaling 3b which inhibits leptin signaling. Conclusions The present results are consistent with those seen in mammals treated with GTE, supporting the validity of studying the effects of GTE in DIO zebrafish. Our results suggest that GTE exerts beneficial effects on adiposity, possibly by altering the expression of lipid catabolism genes and SOCS3.

  16. Lpaatδ/Agpat4 deficiency impairs maximal force contractility in soleus and alters fibre type in extensor digitorum longus muscle.

    Science.gov (United States)

    Bradley, Ryan M; Bloemberg, Darin; Aristizabal Henao, Juan J; Hashemi, Ashkan; Mitchell, Andrew S; Fajardo, Val A; Bellissimo, Catherine; Mardian, Emily B; Bombardier, Eric; Paré, Marie-France; Moes, Katherine A; Stark, Ken D; Russell Tupling, A; Quadrilatero, Joe; Duncan, Robin E

    2018-04-05

    Lysophosphatidic acid acyltransferase (LPAAT) δ/acylglycerophosphate acyltransferase 4 is a mitochondrial enzyme and one of five homologues that catalyze the acyl-CoA-dependent synthesis of phosphatidic acid (PA) from lysophosphatidic acid. We studied skeletal muscle LPAATδ and found highest levels in soleus, a red oxidative fibre-type that is rich in mitochondria, and lower levels in extensor digitorum longus (EDL) (white glycolytic) and gastrocnemius (mixed fibre-type). Using Lpaatδ-deficient mice, we found no change in soleus or EDL mass, or in treadmill time-to-exhaustion compared to wildtype littermates. There was, however, a significant reduction in the proportion of type I and type IIA fibres in EDL but, surprisingly, not soleus, where these fibre-types predominate. Also unexpectedly, there was no impairment in force generation by EDL, but a significant reduction by soleus. Oxidative phosphorylation and activity of complexes I, I + II, III, and IV in soleus mitochondria was unchanged and therefore could not explain this effect. However, pyruvate dehydrogenase activity was significantly reduced in Lpaatδ -/- soleus and EDL. Analysis of cellular lipids indicated no difference in soleus triacylglycerol, but specific elevations in soleus PA and phosphatidylethanolamine levels, likely due to a compensatory upregulation of Lpaatβ and Lpaatε in Lpaatδ -/- mice. An anabolic effect for PA as an activator of skeletal muscle mTOR has been reported, but we found no change in serine 2448 phosphorylation, indicating reduced soleus force generation is unlikely due to the loss of mTOR activation by a specific pool of LPAATδ-derived PA. Our results identify an important role for LPAATδ in soleus and EDL. Copyright © 2018. Published by Elsevier B.V.

  17. Profiling eIF2a-Dependent Translation in Synaptic Plasticity and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Learning, memory, and perception rely on an intricate network of proteins that orchestrate the human brain's higher cognitive functions. Protein synthesis, also known as translation, is an important biological process that regulates the function of these molecules. Dysregulation of translation leads to pathological conditions ...

  18. Regarding the classification of a partner or shareholder as a dependant employee

    Directory of Open Access Journals (Sweden)

    Alfredo Sierra Herrero

    2011-11-01

    Full Text Available This article analyzes the juridical controversy related to whether a person that providesservices to a company in which is partner, can be qualified or considered as adependent employee of it. In order to accomplish that purpose, the article providesa critical study of the doctrine of the Chilean Department of Labor (Dirección deTrabajo in contrast to the jurisprudence of the Chilean courts of justice. From there,the author develops criteria that can serve as guidance towards the resolution of disputesof this nature. To this end, an interdisciplinary study is done, which combinesboth the essential elements of the contract of employment, mainly the element ofalienation, with the characteristics of each type of company.

  19. Adoption and Business Value of Mobile Retail Channel: A Dependency Perspective on Mobile Commerce

    Science.gov (United States)

    Chou, Yen-Chun

    2013-01-01

    Forrest Research estimated that revenues derived from mobile devices will grow at an annual rate of 39% to reach $31 billion by 2016. With the tremendous market growth, mobile banking, mobile marketing, and mobile retailing have been recently introduced to satisfy customer needs. Academic and practical articles have widely discussed unique…

  20. Pollination of Australian Macrozamia cycads (Zamiaceae): effectiveness and behavior of specialist vectors in a dependent mutualism.

    Science.gov (United States)

    Terry, L Irene; Walter, Gimme H; Donaldson, John S; Snow, Elizabeth; Forster, Paul I; Machin, Peter J

    2005-06-01

    Complementary field and laboratory tests confirmed and quantified the pollination abilities of Tranes sp. weevils and Cycadothrips chadwicki thrips, specialist insects of their respective cycad hosts, Macrozamia machinii and M. lucida. No agamospermous seeds were produced when both wind and insects were excluded from female cones; and the exclusion of wind-vectored pollen alone did not eliminate seed set, because insects were able to reach the cone. Based on enclosure pollination tests, each weevil pollinates an average 26.2 ovules per cone and each thrips 2.4 ovules per cone. These pollinators visited similar numbers of ovules per cone in fluorescent dye tests that traced insect movement through cones. Fluorescent dye granules deposited by Cycadothrips were concentrated around the micropyle of each visited ovule, the site of pollen droplet release, where pollen must be deposited to achieve pollination. In contrast, Tranes weevils left dye scattered on different areas of each visited ovule, indicating that chance plays a greater role in this system. Each weevil and 25 thrips delivered 6.2 and 5.2 pollen grains, respectively, on average, to each visited ovule per cone, based on examination of dissected pollen canals. In sum, the pollination potential of 25 Cycadothrips approximates that of one Tranes weevil.

  1. A dependability modeling of software under hardware faults digitized system in nuclear power plants

    International Nuclear Information System (INIS)

    Choi, Jong Gyun

    1996-02-01

    An analytic approach to the dependability evaluation of software in the operational phase is suggested in this work with special attention to the physical fault effects on the software dependability : The physical faults considered are memory faults and the dependability measure in question is the reliability. The model is based on the simple reliability theory and the graph theory with the path decomposition micro model. The model represents an application software with a graph consisting of nodes and arcs that probabilistic ally determine the flow from node to node. Through proper transformation of nodes and arcs, the graph can be reduced to a simple two-node graph and the software failure probability is derived from this graph. This model can be extended to the software system which consists of several complete modules without modification. The derived model is validated by the computer simulation, where the software is transformed to a probabilistic control flow graph. Simulation also shows a different viewpoint of software failure behavior. Using this model, we predict the reliability of an application software and a software system in a digitized system(ILS system) in the nuclear power plant and show the sensitivity of the software reliability to the major physical parameters which affect the software failure in the normal operation phase. The derived model is validated by the computer simulation, where the software is transformed to a probabilistic control flow graph. Simulation also shows a different viewpoint of software failure behavior. Using this model, we predict the reliability of an application software and a software system in a digitized system (ILS system) is the nuclear power plant and show the sensitivity of the software reliability to the major physical parameters which affect the software failure in the normal operation phase. This modeling method is particularly attractive for medium size programs such as software used in digitized systems of nuclear power plants. This modeling method is particularly attractive for medium size programs such as software used in digitized systems of nuclear power plants

  2. Regulation of 2-5A Dependent RNase at the Level of its Phosphorylation

    Science.gov (United States)

    1991-06-26

    involved in the control of cell growth ( Kimchi et al., 1981a and 1981b). As regulators of cell growth and differentiation, the IFN inducible enzymes of...cells, resulting in a 5- fold increase in the synthesis to degradation ratio ( Kimchi et al., 1981). A dual action of 2𔃿’PDi and synthetase has been...the mitogen Concanavalin A causes a several fold increase in the level of (2’,5’) PDi without affecting the level of 2-5A synthetase ( Kimchi et al

  3. Biological and environmental drivers of energy allocation in a dependent mammal, the Antarctic fur seal pup.

    Science.gov (United States)

    McDonald, Birgitte I; Goebel, Michael E; Crocker, Daniel E; Costa, Daniel P

    2012-01-01

    Little is known about how variation in the pattern and magnitude of parental effort influences allocation decisions in offspring. We determined the energy budget of Antarctic fur seal pups and examined the relative importance of timing of provisioning, pup traits (mass, condition, sex), and weather (wind chill and solar radiation) on allocation of energy obtained in milk by measuring milk energy intake, field metabolic rate (FMR), and growth rate in 48 Antarctic fur seal pups over three developmental stages (perinatal, premolt, and molt). The relative amount of milk energy used for growth was 59.1% ± 8.1% during the perinatal period but decreased to 23.4% ± 15.5% and 26.0% ± 13.9% during the premolt and molt. This decrease was associated with a greater amount of time spent fasting, along with an increase in pup activity while the mother was at sea foraging. Average daily milk intake, pup mass, and condition were all important in determining how much energy was available for growth, but the amount of energy obtained as milk was the single most important factor determining pup growth. While mean mass-specific FMR did not change with developmental stage (range = 1.74-1.77 mL O(2)/g/h), the factors that accounted for variation in FMR did. Weather (wind chill and solar radiation) and pup traits (mass and condition) influenced mass-specific FMR, but these impacts varied across development. This study provides information about the factors influencing how offspring allocate energy toward growth and maintenance and improves our predictions about how a changing environment may affect energy allocation in pups.

  4. FINAL REMINDER EXTENSION/SUPPRESSION OF ALLOWANCE FOR A DEPENDENT CHILD AGED 18 AND ABOVE

    CERN Multimedia

    Social and Statutory Conditions; Tel. 72862-74474

    2000-01-01

    Members of the personnel with dependent children aged 18 or above (or reaching 18 during the 2000/2001 school year) who have not yet provided a SCHOOL CERTIFICATE must do so as soon as possible. If we have not received this certificate by November 28, 2000 at the latest, the child allowance will be withdrawn retroactively as from September 1,2000.

  5. Protein kinase A-dependent transactivation by the E2A-Pbx1 fusion protein.

    Science.gov (United States)

    Ogo, A; Waterman, M R; Kamps, M P; Kagawa, N

    1995-10-27

    The chimeric gene E2A-PBX1 is formed by the t(1;19) chromosomal translocation exclusively associated with pediatric pre-B cell acute lymphoblastic leukemia (pre-B ALL). The resultant fusion protein from this chimeric gene contains the DNA-binding homeodomain of Pbx1. The first and only functional Pbx1 binding site has been localized in bovine CYP17 to a sequence (CRS1) that participates in cAMP-dependent transcription of this gene encoding the steroid hydroxylase, 17 alpha-hydroxylase cytochrome P450. Because Pbx1 is not expressed in pre-B cells, it may be possible that the E2a-Pbx1 fusion protein expressed in pre-B cells having this translocation will activate, in response to cAMP, transcription of genes not normally expressed in these cells leading to arrest of differentiation at the pre-B cell stage. We have now shown that reporter genes comprising CRS1 are activated transcriptionally by protein kinase A (PKA) in the pre-B cell line 697, which endogenously expresses the fusion protein, and that overexpression of E2A-Pbx1 in additional cell lines enhances transcription of reporter genes in a PKA-dependent fashion. Thus, it seems plausible that arrest in the pre-B stage leading to pre-B ALL includes cAMP-dependent activation of E2A-Pbx1.

  6. Stat3/Cdc25a-dependent cell proliferation promotes embryonic axis extension during zebrafish gastrulation.

    Directory of Open Access Journals (Sweden)

    Yinzi Liu

    2017-02-01

    Full Text Available Cell proliferation has generally been considered dispensable for anteroposterior extension of embryonic axis during vertebrate gastrulation. Signal transducer and activator of transcription 3 (Stat3, a conserved controller of cell proliferation, survival and regeneration, is associated with human scoliosis, cancer and Hyper IgE Syndrome. Zebrafish Stat3 was proposed to govern convergence and extension gastrulation movements in part by promoting Wnt/Planar Cell Polarity (PCP signaling, a conserved regulator of mediolaterally polarized cell behaviors. Here, using zebrafish stat3 null mutants and pharmacological tools, we demonstrate that cell proliferation contributes to anteroposterior embryonic axis extension. Zebrafish embryos lacking maternal and zygotic Stat3 expression exhibit normal convergence movements and planar cell polarity signaling, but transient axis elongation defect due to insufficient number of cells resulting largely from reduced cell proliferation and increased apoptosis. Pharmacologic inhibition of cell proliferation during gastrulation phenocopied axis elongation defects. Stat3 regulates cell proliferation and axis extension in part via upregulation of Cdc25a expression during oogenesis. Accordingly, restoring Cdc25a expression in stat3 mutants partially suppressed cell proliferation and gastrulation defects. During later development, stat3 mutant zebrafish exhibit stunted growth, scoliosis, excessive inflammation, and fail to thrive, affording a genetic tool to study Stat3 function in vertebrate development, regeneration, and disease.

  7. A-dependence of hadron-nucleus massive lepton pair production

    International Nuclear Information System (INIS)

    Ayala Filho, A.L.; Ducati, M.B. Gay; Epele, L.N.; Canal, C.A. Garcia

    1995-01-01

    The nuclear effects in the small x region of hadron-nucleus Drell-Yan processes at 800 GeV analyzed. We employ the parton recombination model to describe the suppression in the R pA DY (x 2 ) ratio as compared with R EMC (x), in the same kinematical region. A good agreement with experimental results is obtained. (author)

  8. 26 CFR 1.152-1 - General definition of a dependent.

    Science.gov (United States)

    2010-04-01

    ... his son during 1955, all of which sums represent his sole support during that year. The fact that the.... Consequently, since the son's contribution of $1,000 was less than one-half of the father's support ($2,200) he... for the entire part of the year preceding his death. Likewise, the period during the taxable year...

  9. Domestic Violence Screening and Service Acceptance among Adult Victims in a Dependency Court Setting

    Science.gov (United States)

    Rivers, James E.; Maze, Candice L.; Hannah, Stefanie A.; Lederman, Cindy S.

    2007-01-01

    Many child welfare systems are unable to effectively identify and address co-occurring domestic violence and child maltreatment. In response, the Dependency Court Intervention Program for Family Violence implemented a protocol to identify indicators of domestic violence in families involved with child protection proceedings. This article…

  10. Extending Phrase-Based Decoding with a Dependency-Based Reordering Model

    Science.gov (United States)

    2009-11-01

    agreement morphology . Working with dependency trees rather than constituency trees allows us to take advantage of the flexibility of phrase-based...appropriately ordered and ready-made with the appropriate agreement morphology . Working with dependency trees rather than constituency trees allows us to take...contiguous target-language words. These “phrases” need not be phrases in the sense of any pre-existing theory of natural language syntax . Indeed the

  11. Nurses’ perception on The difficulties and information needs of family members caring for a dependent person

    Directory of Open Access Journals (Sweden)

    Maria José Lumini Landeiro

    2016-01-01

    Full Text Available La transición de personas con dependencia del hospital hacia la casa es una situación estresante para ellos y sus familias. Este estudio descriptivo exploratorio con abordaje cualitativo tuve como objetivo conocer la percepción de los enfermeros sobre las dificultades, necesidades de información y aplicabilidad del uso de tecnologías educacionales por los familiares cuidadores. Para la recolección de datos se realizaron entrevistas semiestructuradas a 14 enfermeros de un hospital y dos centros de sanidad de Oporto. Los resultados han mostrado participantes en su mayoría hombres con edad media 32,64 años y 9,86 años de media de ejercicio profesional. Los enfermeros han identificado necesidades de información para el desarrollo de competencias en los dominios del conocimiento instrumental relativos al auto-cuidado alimentarse, girar en la cama y transferirse y utilidad del uso de tecnología instrumental. Se concluyó que las áreas de conocimiento identificadas facilitarían la construcción y aplicación de tecnología educativa para familiares cuidadores.

  12. THE MEANING OF BEING-A-CAREGIVER OF A DEPENDENT RELATIVE SUFFERING FROM CANCER: PALLIATIVE CONTRIBUTIONS

    Directory of Open Access Journals (Sweden)

    Joisy Aparecida Marchi

    2016-01-01

    Full Text Available Se tuvo como objetivo comprender el significado de ser-cuidador de un familiar con cáncer y con gran dependencia para las actividades diarias. Estudio fenomenológico fundamentado en Martín Heidegger realizado junto a tres núcleos integrados de salud en un municipio del noroeste de Paraná. La entrevista sucedió entre noviembre de 2012 y febrero de 2013 con 17 cuidadores familiares. Del análisis propuesto surgieron dos temáticas: “El ser-cuidador vivenciando distintos modos de disposición” y “Siendo-con-el: de la ocupación cotidiana a la preocupación libertadora”. Significó para el ser-cuidador aterrarse con el diagnóstico, horrorizarse con el tratamiento, aterrorizarse con los cuidados paliativos y ser-con-el-otro en la enfermedad. Se mostró ocupado con las cosas, pero también estuvo preocupado, evidenciando la solicitud en sus acciones. Esta base para un cuidado paliativo efectivo, debe permear la labor del enfermero visando que este profesional sea un verdadero ser-del-cuidado.

  13. On the A-dependence of σL/σT: Skeletons in the shadow

    International Nuclear Information System (INIS)

    Milana, J.

    1994-01-01

    A most counter-intuitive dependence in the differential cross-section in the shadowing regime is shown to result from a higher-twist nuclear enhancement in R = σ L /σ T which severely complicates the unravelling from present data the corresponding dependence in Q 2 of the nuclear structure functions, F 2 A (x,Q 2 ). Indeed, until precision measurements close this loophole, the extrapolations of the structure functions to either higher Q 2 or other processes (as is necessary to address present data at FNAL or future experiments at RHIC) must be considered problematic. The contribution CEBAF can make in this regard by providing systematic determination of R A (x, Q 2 ) is thus emphasized. The purpose of this talk is to motivate an experiment CEBAF can and should do, especially if upgraded to higher energies. While providing information on nuclear structure that is interesting in itself, the added motivation is that precision results will have important impact on other high-energy experiments involving nuclear targets that have been, and will continue to be done all over the world

  14. A dependent stress-strength interference model based on mixed copula function

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jian Xiong; An, Zong Wen; Liu, Bo [School of Mechatronics Engineering, Lanzhou University of Technology, Lanzhou (China)

    2016-10-15

    In the traditional Stress-strength interference (SSI) model, stress and strength must satisfy the basic assumption of mutual independence. However, a complex dependence between stress and strength exists in practical engineering. To evaluate structural reliability under the case that stress and strength are dependent, a mixed copula function is introduced to a new dependent SSI model. This model can fully characterize the dependence between stress and strength. The residual square sum method and genetic algorithm are also used to estimate the unknown parameters of the model. Finally, the validity of the proposed model is demonstrated via a practical case. Results show that traditional SSI model ignoring the dependence between stress and strength more easily overestimates product reliability than the new dependent SSI model.

  15. LuxS impacts on LytA-dependent autolysis and on competence in Streptococcus pneumoniae.

    Science.gov (United States)

    Romao, Susana; Memmi, Guido; Oggioni, Marco R; Trombe, Marie-Claude

    2006-02-01

    The ubiquitous protein LuxS with S-ribosylhomocysteinase activity is involved in S-adenosyl methionine detoxification, C-1 unit recycling and the production of autoinducers that allow the cell to sense and respond to cell density. Independent reports describe the impact of LuxS deficiency on Streptococcus pneumoniae virulence in the mouse. In vitro, LuxS deficiency confers discrete phenotypes. A combined approach using genetic dissection and mixed-culture experiments allowed the involvement of LuxS in the developmental physiology of S. pneumoniae to be investigated. Functional LuxS was found to be related on the one hand to down-regulation of competence, and on the other hand to attenuation of autolysis in cultures entering stationary phase. The competence phenotype of luxS mutant bacteria was complemented by media conditioned by competence-defective ComAB0 bacteria, but not by BSA. The autolytic phenotype was complemented by BSA, but not by conditioned supernatants. It is suggested that the impact of LuxS on competence, but not on autolysis, involves cell-cell communication. The phenotype of luxS mutant strains reveals a hierarchy in the competence regulatory networks of S. pneumoniae.

  16. Profiling eIF2a-Dependent Translation in Synaptic Plasticity and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... Parkinson's disease, motor neuron disease, Huntington's disease, and prion diseases (which are spongiform encephalopathies, such as bovine spongiform encephalopathy and Creutzfeldt-Jakob disease). A key molecule regulating protein synthesis is eIF2. Recent studies have shown that modulation of eIF2 activity can ...

  17. Towards a dependable homogeneous many-processor system-on-chip

    NARCIS (Netherlands)

    Zhang, X.

    2014-01-01

    Nowadays, dependable computing systems are widely required in mission critical and human-life critical applications. While the advance in CMOS technology enables smaller and faster circuits, the dependability of modern ICs has worsened as a result of the shrinking dimensions of MOS transistors and

  18. Economic Value Added as a Dependence on the Corporate- and Market-life Cycle

    Directory of Open Access Journals (Sweden)

    Konečný Zdeněk

    2011-06-01

    Full Text Available Economic value added (EVA is an indicator which is widely used as the main tool for financial analysis. There are two methods of calculating it. The original method which was made by Stern & Stewart is defined as the net operating profit after taxes minus the cost of capital. The second method which was developed and used by the “Czech Ministry of Industry and Trade” indicates that, the economic value added is the difference between return on equity and the alternate cost of equity that is composed of separate risk rewards, and this “spread” is consequently multiplied by the equity. Economic value added depends on many factors. Whereas some of them are controllable by the company, others are not. This article is focused on the relationship between economic value added and the corporate- vs. market life cycle. This is because, there is an assumption that conditions for developing EVA changes depending on the actual phase of corporate- and market life cycle. In this research, the model by Reiners (2004 is used to identify the phases of corporate- and market life cycle and the method provided by the “Czech Ministry of Industry and Trade” is used to calculate EVA. However, there is a consideration of the relativity of EVA in the form of “spread” because of the intercompany comparison. The study found that, the highest spread is achieved by companies that are in the phase of expansion and phase of market expansion. On the contrary, companies in the phase of declension during market declension achieved the lowest and negative spread.

  19. A dependência na tecnologia espacial em operações militares

    OpenAIRE

    Costa, Engel

    2013-01-01

    A presente investigação visa a identificação e avaliação do tipo de suporte que a tecnologia espacial garante às operações militares. Procurou-se identificar os nichos de aplicação e ligações estruturantes desta tecnologia no apoio às operações militares, de guerra e não guerra. A investigação realizada focou essencialmente os Estados Unidos da América e Europa. O primeiro por ser o ator na vanguarda desta tecnologia e pelo seu papel nos recentes conflitos. A Europa sobretudo pela ação da ...

  20. Modeling of a dependence between human operators in advanced main control rooms

    International Nuclear Information System (INIS)

    Lee, Seung Jun; Kim, Jaewhan; Jang, Seung-Cheol; Shin, Yeong Cheol

    2009-01-01

    For the human reliability analysis of main control room (MCR) operations, not only parameters such as the given situation and capability of the operators but also the dependence between the actions of the operators should be considered because MCR operations are team operations. The dependence between operators might be more prevalent in an advanced MCR in which operators share the same information using a computerized monitoring system or a computerized procedure system. Therefore, this work focused on the computerized operation environment of advanced MCRs and proposed a model to consider the dependence representing the recovery possibility of an operator error by another operator. The proposed model estimates human error probability values by considering adjustment values for a situation and dependence values for operators during the same operation using independent event trees. This work can be used to quantitatively calculate a more reliable operation failure probability for an advanced MCR. (author)

  1. Comorbidade com a dependência de substâncias nos subtipos da fobia social

    OpenAIRE

    D’El Rey, Gustavo J. Fonseca; Pacini, Carla Alessandra

    2008-01-01

    Estudos epidemiológicos têm identifi cado 2 subtipos de fobia social: a fobia social relacionada somente com ofalar, que é caracterizada pelo temor das situações de falar em público, e a fobia social generalizada, que é caracterizada pelotemor de diversas situações sociais. A fobia social de falar em público corresponde na DSM-IV à fobia social circunscrita,enquanto o outro subtipo corresponde à fobia social ge...

  2. SHMT2 drives glioma cell survival in ischaemia but imposes a dependence on glycine clearance.

    Science.gov (United States)

    Kim, Dohoon; Fiske, Brian P; Birsoy, Kivanc; Freinkman, Elizaveta; Kami, Kenjiro; Possemato, Richard L; Chudnovsky, Yakov; Pacold, Michael E; Chen, Walter W; Cantor, Jason R; Shelton, Laura M; Gui, Dan Y; Kwon, Manjae; Ramkissoon, Shakti H; Ligon, Keith L; Kang, Seong Woo; Snuderl, Matija; Vander Heiden, Matthew G; Sabatini, David M

    2015-04-16

    Cancer cells adapt their metabolic processes to support rapid proliferation, but less is known about how cancer cells alter metabolism to promote cell survival in a poorly vascularized tumour microenvironment. Here we identify a key role for serine and glycine metabolism in the survival of brain cancer cells within the ischaemic zones of gliomas. In human glioblastoma multiforme, mitochondrial serine hydroxymethyltransferase (SHMT2) and glycine decarboxylase (GLDC) are highly expressed in the pseudopalisading cells that surround necrotic foci. We find that SHMT2 activity limits that of pyruvate kinase (PKM2) and reduces oxygen consumption, eliciting a metabolic state that confers a profound survival advantage to cells in poorly vascularized tumour regions. GLDC inhibition impairs cells with high SHMT2 levels as the excess glycine not metabolized by GLDC can be converted to the toxic molecules aminoacetone and methylglyoxal. Thus, SHMT2 is required for cancer cells to adapt to the tumour environment, but also renders these cells sensitive to glycine cleavage system inhibition.

  3. SHMT2 drives glioma cell survival in ischaemia but imposes a dependence on glycine clearance.

    NARCIS (Netherlands)

    Kim, D.; Fiske, B.P.; Birsoy, K.; Freinkman, E.; Kami, K.; Possemato, R.L.; Chudnovsky, Y.; Pacold, M.E.; Chen, W.W.; Cantor, J.R.; Shelton, L.M.; Gui, D.Y.; Kwon, M.; Ramkissoon, S.H.; Ligon, K.L.; Kang, S.W.; Snuderl, M.; der Heiden, M.G. Van; Sabatini, D.M.

    2015-01-01

    Cancer cells adapt their metabolic processes to support rapid proliferation, but less is known about how cancer cells alter metabolism to promote cell survival in a poorly vascularized tumour microenvironment. Here we identify a key role for serine and glycine metabolism in the survival of brain

  4. Flat Milling Process Simulation Taking into Consideration a Dependence of Dynamic Characteristics of the Machine

    Directory of Open Access Journals (Sweden)

    D. A. Zavarzin

    2016-01-01

    Full Text Available The milling process inherently is on/off, and therefore inevitably there is vibration excitation in the Machine/Fixture/Tool/Part (MFTP system, which results in a different quality of the treated surface, depending on the machining conditions. The objective is to identify effective operation conditions to cut a part on the 3-way easy class machines when there is no unwanted regenerative self-oscillation, leading to a significant deterioration in the quality of the surface machined. The paper describes vibrations arising during a milling process and their effect on the surface shape and the working tool. To solve this problem we apply a numerical simulation method of cutting dynamics, which consist of 4 modules. The main module is an algorithm of the geometric simulation. The second module is a phenomenological model of the cutting forces. Two remaining modules are responsible for dynamics simulation of the part machined and the cutting tool under time-varying cutting forces. The calculated values are transferred back to the geometric modelling algorithm at each step in time. Thus, the model is closed and allows us to take into account an effect of delay in a dynamic system. A finite element machine model to perform calculation in 3DCUT software has been a selected and compiled. The paper presents geometrical mapping of the machining process and natural frequencies and shapes found for the finite element model. Conducting multivariate calculations allowed us to analyse the dependences of a dynamic behaviour of the system on changing spindle speed. The multivariate modelling results are presented as the Poincare maps for a moving free end of the tool. These Poincare maps allow us to select the operation conditions domains coming both with forced vibration and with self-excited oscillations. On the Poincaré map for two operation conditions of different domains there are graphics of the cutting forces, a thickness of the cutting layer, tool movements, and a shape of the machined surface to demonstrate differences in the dynamic behaviour of the system. A milling process modelling technique considered in the paper, taking into account a dynamics of the cutting 3-way machine of easy class allows us to estimate the nature and the level of vibration in the processing system, depending on the operation conditions selected for machining through building the Poincaré maps based on the results of multivariate modelling. These results can be used to select the effective milling operation conditions that enhance the quality and processing performance.

  5. A Dependence between Average Call Duration and Voice Transmission Quality: Measurement and applications

    NARCIS (Netherlands)

    Holub, J.; Beerends, J.G.; Smid, R.

    2004-01-01

    This contribution deals with the estimation of the relation between speech transmission quality and average call duration for a given network and portfolio of customers. It uses non-intrusive speech quality measurements on live speech calls. The basic idea behind this analysis is an expectation that

  6. Protein kinase A-dependent step(s) in hepatitis C virus entry and infectivity

    NARCIS (Netherlands)

    Farquhar, Michelle J.; Harris, Helen J.; Diskar, Mandy; Jones, Sarah; Mee, Christopher J.; Nielsen, Soren U.; Brimacombe, Claire L.; Molina, Sonia; Toms, Geoffrey L.; Maurel, Patrick; Howl, John; Herberg, Friedrich W.; van Ijzendoorn, Sven C. D.; Balfe, Peter; McKeating, Jane A.

    Viruses exploit signaling pathways to their advantage during multiple stages of their life cycle. We demonstrate a role for protein kinase A (PKA) in the hepatitis C virus (HCV) life cycle. The inhibition of PKA with H89, cyclic AMP (cAMP) antagonists, or the protein kinase inhibitor peptide reduced

  7. The partly Aalen's model for recurrent event data with a dependent terminal event.

    Science.gov (United States)

    Chen, Chyong-Mei; Shen, Pao-Sheng; Chuang, Ya-Wen

    2016-01-30

    Recurrent event data are commonly observed in biomedical longitudinal studies. In many instances, there exists a terminal event, which precludes the occurrence of additional repeated events, and usually there is also a nonignorable correlation between the terminal event and recurrent events. In this article, we propose a partly Aalen's additive model with a multiplicative frailty for the rate function of recurrent event process and assume a Cox frailty model for terminal event time. A shared gamma frailty is used to describe the correlation between the two types of events. Consequently, this joint model can provide the information of temporal influence of absolute covariate effects on the rate of recurrent event process, which is usually helpful in the decision-making process for physicians. An estimating equation approach is developed to estimate marginal and association parameters in the joint model. The consistency of the proposed estimator is established. Simulation studies demonstrate that the proposed approach is appropriate for practical use. We apply the proposed method to a peritonitis cohort data set for illustration. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Serum autotaxin is increased in pruritus of cholestasis, but not of other origin, and responds to therapeutic interventions

    NARCIS (Netherlands)

    Kremer, Andreas E.; van Dijk, Remco; Leckie, Pamela; Schaap, Frank G.; Kuiper, Edith M. M.; Mettang, Thomas; Reiners, Katrin S.; Raap, Ulrike; van Buuren, Henk R.; van Erpecum, Karel J.; Davies, Nathan A.; Rust, Christian; Engert, Andreas; Jalan, Rajiv; Oude Elferink, Ronald P. J.; Beuers, Ulrich

    2012-01-01

    Pruritus is a seriously disabling symptom accompanying many cholestatic liver disorders. Recent experimental evidence implicated the lysophospholipase, autotaxin (ATX), and its product, lysophosphatidic acid (LPA), as potential mediators of cholestatic pruritus. In this study, we highlight that

  9. História da enfermagem psiquiátrica e a dependência química no Brasil: atravessando a história para reflexão Historia de la enfermería psiquiátrica y la dependencia química en el Brasil: atravesando la historia para la reflexión History of the psychiatric nursing and chemical dependency in Brazil: crossing the history for reflection

    Directory of Open Access Journals (Sweden)

    Amanda Márcia dos Santos Reinaldo

    2007-12-01

    Full Text Available A formação do enfermeiro em Enfermagem Psiquiátrica e na área de dependências químicas norteia a discussão desse artigo, tendo em vista a complexidade dos problemas relacionados ao ensino de enfermagem, saúde mental, psiquiatria e álcool e drogas. Trata-se de um artigo de revisão de literatura onde as autoras compilaram fontes primárias e secundárias sobre o tema e, a partir da leitura do material bibliográfico, fizeram análises e reflexões acerca dos atravessamentos históricos que permeiam a história da Enfermagem Psiquiátrica e a dependência química no Brasil. Os resultados apontam para uma evolução do tema álcool e drogas dada a magnitude do problema na sociedade contemporânea. Em relação à Enfermagem Psiquiátrica, o ensino apresenta mudanças devidas à evolução histórica da psiquiatria que devem ser consideradas durante a formação do profissional enfermeiro. Ambas as temáticas encontram pontos de aproximação e distanciamento conforme o contexto em que são analisadas.La formación del enfermero en enfermería psiquiátrica y en el área de dependencias químicas, orienta la discusión de este artículo teniendo a la vista la complejidad de los problemas relacionados con la enseñanza de enfermería, salud mental, psiquiátrica, alcohol y drogas. Se trata de un artículo de revisión de la literatura donde las autoras compilaron fuentes primarias y secundarias sobre el tema y a partir de la lectura del material bibliográfico se realizaron análisis y reflexiones acerca de los acontecimientos históricos que permean la historia de la enfermería psiquiátrica y la dependencia química en el Brasil. Los resultados apuntan para una evolución del tema alcohol y drogas debido a la magnitud del problema en la sociedad contemporánea. En relación a la enfermería psiquiátrica, la enseñanza presenta cambios debido a la evolución histórica de la psiquiátrica que deben ser consideradas durante la formaci

  10. Cholesterol absorption inhibitors as a therapeutic option for hypercholesterolaemia.

    Science.gov (United States)

    Burnett, John R; Huff, Murray W

    2006-11-01

    The development of cholesterol-lowering drugs (including a variety of statins, bile acid-binding resins and recently discovered inhibitors of cholesterol absorption) has expanded the options for cardiovascular prevention. Recent treatment guidelines emphasise that individuals at substantial risk for atherosclerotic coronary heart disease should meet defined targets for LDL cholesterol concentrations. Combination therapy with drugs that have different or complementary mechanisms of action is often needed to achieve lipid goals. Existing approaches to the treatment of hypercholesterolaemia are still ineffective in halting the progression of coronary artery disease in some patients despite combination therapies. Other patients are resistant to conventional drug treatment and remain at high risk for the development and progression of atherosclerotic cardiovascular disease and alternative approaches are needed. The discovery and development of ezetimibe (a novel, selective and potent cholesterol absorption inhibitor) has advanced the treatment of hypercholesterolaemia. New agents including the phytostanol preparation FM-VP4 and inhibitors of acyl coenzyme A:cholesterol acyltransferase, the apical Na(+)-dependent bile acid transporter and microsomal triglyceride transfer protein may also play a future role in combination therapy. This review focuses on the recent progress in the molecular mechanisms of intestinal cholesterol absorption and transport, and novel therapeutic approaches to inhibit the cholesterol absorption process.

  11. Lipoprotein responses to fish, coconut and soybean oil diets with and without cholesterol in the Syrian hamster.

    Science.gov (United States)

    Lin, M H; Lu, S C; Hsieh, J W; Huang, P C

    1995-12-01

    Thirty-six young male Syrian hamsters were fed with test diets containing coconut oil, soybean oil or fish oil with and without 0.5% cholesterol for 6 weeks. Without dietary cholesterol supplementation, animals on the fish oil diet had significantly lower plasma total triglyceride (TG) and total cholesterol than those on the coconut oil or soybean oil diet. The decrease of TG was seen mainly in the very low density lipoprotein (VLDL) fraction. The degree of decrease in cholesterol was similar in all of the lipoprotein fractions. With 0.5% dietary cholesterol supplementation, there was no significant difference in plasma TG level among the three dietary groups. However, the fish oil group had significantly higher plasma cholesterol than the coconut oil and soybean oil groups. The increase of cholesterol was mainly in the VLDL and low density lipoprotein (LDL) fractions. In contrast to the plasma cholesterol level, the hepatic cholesteryl ester content was significantly lower in the cholesterol-supplemented fish oil group than in the coconut oil and soybean oil counterparts. The cholesterol-supplemented fish oil group showed higher liver microsomal acyl-coenzyme A:cholesterol acyltransferase activity than the other two groups, while there was no significant difference in the excretion of fecal neutral and acidic sterols among the three dietary groups.

  12. Silencing of ACO decreases reproduction and energy metabolism in triazophos-treated female brown plant hoppers, Nilaparvata lugens Stål (Hemiptera: Delphacidae).

    Science.gov (United States)

    Liu, Zong-Yu; Jiang, Yi-Ping; Li, Lei; You, Lin-Lin; Wu, You; Xu, Bin; Ge, Lin-Quan; Wu, Jin-Cai

    2016-03-01

    The brown plant hopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), is a major pest affecting rice in Asia, and outbreaks of this pest are closely linked to pesticide-induced stimulation of reproduction. Therefore, the BPH is a classic example of a resurgent pest. However, the effects of different genes on the regulation of pesticide-induced reproductive stimulation in the BPH are unclear. In this study, the regulatory effects of acyl-coenzyme A oxidase (ACO) on the reproduction and biochemistry of the BPH were investigated with gene silencing. The number of eggs laid per female by triazophos (TZP)+dsACO BPH females was significantly lower than those of TZP-treated (without ACO silencing) or TZP+GFP females (negative control), with the number of eggs decreasing by 30.8% (from 529.5 to 366.3) and 32.0% (from 540.5 to 366.3), respectively. The preoviposition period, oviposition period, and longevity of the TZP-treated females were also influenced by dsACO treatment. Additionally, the amounts of crude fat, protein, and some fatty acids (oleic acid, palmitic acid, linoleic acid, stearic acid, and myristoleic acid) in TZP+dsACO females were significantly lower than in TZP-treated females. Thus, ACO is one of the key genes regulating the TZP-induced stimulation of reproduction in BPH females. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Distinct Structural Elements Dictate the Specificity of the Type III Pentaketide Synthase from Neurospora crassa

    Energy Technology Data Exchange (ETDEWEB)

    Rubin-Pitel, Sheryl B.; Zhang, Houjin; Vu, Trang; Brunzelle, Joseph S.; Zhao, Huimin; Nair, Satish K. (UIUC); (NWU)

    2009-01-15

    The fungal type III polyketide synthase 2'-oxoalkylresorcyclic acid synthase (ORAS) primes with a range of acyl-Coenzyme A thioesters (C{sub 4}--C{sub 20}) and extends using malonyl-Coenzyme A to produce pyrones, resorcinols, and resorcylic acids. To gain insight into this unusual substrate specificity and product profile, we have determined the crystal structures of ORAS to 1.75 {angstrom} resolution, the Phe-252{yields}Gly site-directed mutant to 2.1 {angstrom} resolution, and a binary conplex of ORAS with eicosanoic acid to 2.0 {angstrom} resolution. The structures reveal a distinct rearrangement of structural elements near the active site that allows accomodation of long-chain fatty acid esters and a reorientation of the gating mechanism that controls cyclization and polyketide chain length. The roles of these structural elements are further elucidated by characterization of various structure-based site-directed variants. These studies establish an unexpected plasticity to the PKS fold, unanticipated from structural studies of other members of this enzyme family.

  14. Network analysis of hepatic genes responded to high-fat diet in C57BL/6J mice: nutrigenomics data mining from recent research findings.

    Science.gov (United States)

    Kim, Eun Jung; Kim, Eunjung; Kwon, Eun-Young; Jang, Hyun-Seo; Hur, Cheol-Goo; Choi, Myung-Sook

    2010-08-01

    Obesity and its associated complications, including diabetes, dyslipidemia, atherosclerosis, and some cancers, have been a global health problem with a rapid increase of the obese population. In this study, we selected 31 obesity candidate genes in the liver of high-fat-induced obese C57BL/6J mice through investigation of literature search and analyzed functional protein-protein interaction of the genes using the STRING database. Most of the obesity candidate genes were closely connected through lipid metabolism, and in particular acyl-coenzyme A oxidase 1 appeared to be a core obesity gene. Overall, genes involved in fatty acid beta-oxidation, fatty acid synthesis, and gluconeogenesis were up-regulated, and genes involved in sterol biosynthesis, insulin signaling, and oxidative stress defense system were down-regulated with a high-fat diet. Future identification of core obesity genes and their functional targets is expected to provide a new way to prevent obesity by phytochemicals or functional foods on the basis of food and nutritional genomics.

  15. De novo Biosynthesis of Biodiesel by Escherichia coli in Optimized Fed-Batch Cultivation

    Science.gov (United States)

    Cai, Ke; Tan, Xiaoming; Lu, Xuefeng

    2011-01-01

    Biodiesel is a renewable alternative to petroleum diesel fuel that can contribute to carbon dioxide emission reduction and energy supply. Biodiesel is composed of fatty acid alkyl esters, including fatty acid methyl esters (FAMEs) and fatty acid ethyl esters (FAEEs), and is currently produced through the transesterification reaction of methanol (or ethanol) and triacylglycerols (TAGs). TAGs are mainly obtained from oilseed plants and microalgae. A sustainable supply of TAGs is a major bottleneck for current biodiesel production. Here we report the de novo biosynthesis of FAEEs from glucose, which can be derived from lignocellulosic biomass, in genetically engineered Escherichia coli by introduction of the ethanol-producing pathway from Zymomonas mobilis, genetic manipulation to increase the pool of fatty acyl-CoA, and heterologous expression of acyl-coenzyme A: diacylglycerol acyltransferase from Acinetobacter baylyi. An optimized fed-batch microbial fermentation of the modified E. coli strain yielded a titer of 922 mg L−1 FAEEs that consisted primarily of ethyl palmitate, -oleate, -myristate and -palmitoleate. PMID:21629774

  16. Inhibition of the NLRP3 inflammasome attenuates foam cell formation of THP-1 macrophages by suppressing ox-LDL uptake and promoting cholesterol efflux.

    Science.gov (United States)

    Chen, Liang; Yao, Qiying; Xu, Siwei; Wang, Hongyan; Qu, Peng

    2018-01-01

    The NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome plays an important role in the development of atherosclerosis. The activated NLRP3 inflammasome has been reported to promote macrophage foam cell formation, but not all studies have obtained the same result, and how NLRP3 inflammasome is involved in the formation of foam cells remains elusive. We used selective NLRP3 inflammasome inhibitors and NLRP3-deficient THP-1 cells to assess the effect of NLRP3 inflammasome inhibition on macrophage foam cell formation, oxidized low-density lipoprotein (ox-LDL) uptake, esterification, and cholesterol efflux, as well as the expression of associated proteins. Inhibition of the NLRP3 inflammasome attenuated foam cell formation, diminished ox-LDL uptake, and promoted cholesterol efflux from THP-1 macrophages. Moreover, it downregulated CD36, acyl coenzyme A: cholesterol acyltransferase-1 and neutral cholesterol ester hydrolase expression; upregulated ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type I (SR-BI) expression; but had no effect on the expression of scavenger receptor class A and ATP-binding cassette transporter G1. Collectively, our findings show that inhibition of the NLRP3 inflammasome decreases foam cell formation of THP-1 macrophages via suppression of ox-LDL uptake and enhancement of cholesterol efflux, which may be due to downregulation of CD36 expression and upregulation of ABCA1 and SR-BI expression, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Angiogenin activates phospholipase C and elicits a rapid incorporation of fatty acid into cholesterol esters in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Moore, F.; Riordan, J.F.

    1990-01-01

    Angiogenin activates the phosphoinositide-specific phospholipase C (PLC) in cultured rat aortic smooth muscle cells to yield a transient (30 s) peak of 1,2-diacylglycerol (DG) and inositol trisphosphate. Within 1 min, the DG level falls below that of the control and remains so for at least 20 min. A transient increase in monoacylglycerol indicates that depletion of DG may be the consequence of hydrolysis by DG lipase. In addition to these changes in second messengers, a rapid increase in incorporating of radiolabeled tracer into cellular cholesterol esters is observed. Stimulated cholesterol ester labeling is inhibited by preincubation with either the DG lipase inhibitor RHC 80267 or the acyl coenzyme A:cholesterol acyltransferase inhibitor Sandoz 58035. Cells prelabeled with [ 3 H]arachidonate show a sustained increase in labeling of cholesterol esters following exposure to angiogenin. In contrast, cells prelabeled with [ 3 H]oleate show only a transient elevation that returns to the basal level by 5 min. This suggests initial cholesterol esterification by oleate followed by arachidonate that is released by stimulation of the PLC/DG lipase pathway

  18. ACAT1 deficiency increases cholesterol synthesis in mouse peritoneal macrophages.

    Science.gov (United States)

    Dove, Dwayne E; Su, Yan Ru; Swift, Larry L; Linton, MacRae F; Fazio, Sergio

    2006-06-01

    Acyl-coenzyme A:cholesterol acyltransferase (ACAT) esterifies free cholesterol and stores cholesteryl esters in lipid droplets. Macrophage ACAT1 deficiency results in increased atherosclerotic lesion area in hyperlipidemic mice via disrupted cholesterol efflux, increased lipoprotein uptake, accumulation of intracellular vesicles, and accelerated apoptosis. The objective of this study was to determine whether lipid synthesis is affected by ACAT1. The synthesis, esterification, and efflux of new cholesterol were measured in peritoneal macrophages from ACAT1(-/-) mice. Cholesterol synthesis was increased by 134% (p=0.001) in ACAT1(-/-) macrophages compared to wildtype macrophages. Increased synthesis resulted in a proportional increase in the efflux of newly synthesized cholesterol. Although the esterification of new cholesterol was reduced by 93% (pSREBP1a mRNA was increased 6-fold in ACAT1(-/-) macrophages compared to wildtype macrophages, suggesting an up-regulation of cholesterol and fatty acid synthesis in ACAT1(-/-) macrophages. Increased cholesterol synthesis and up-regulation of SREBP in ACAT1(-/-) macrophages suggests that ACAT1 affects the regulation of lipid metabolism in macrophages. This change in cholesterol homeostasis may contribute to the atherogenic potential of ACAT1(-/-) macrophages.

  19. De novo biosynthesis of biodiesel by Escherichia coli in optimized fed-batch cultivation.

    Science.gov (United States)

    Duan, Yangkai; Zhu, Zhi; Cai, Ke; Tan, Xiaoming; Lu, Xuefeng

    2011-01-01

    Biodiesel is a renewable alternative to petroleum diesel fuel that can contribute to carbon dioxide emission reduction and energy supply. Biodiesel is composed of fatty acid alkyl esters, including fatty acid methyl esters (FAMEs) and fatty acid ethyl esters (FAEEs), and is currently produced through the transesterification reaction of methanol (or ethanol) and triacylglycerols (TAGs). TAGs are mainly obtained from oilseed plants and microalgae. A sustainable supply of TAGs is a major bottleneck for current biodiesel production. Here we report the de novo biosynthesis of FAEEs from glucose, which can be derived from lignocellulosic biomass, in genetically engineered Escherichia coli by introduction of the ethanol-producing pathway from Zymomonas mobilis, genetic manipulation to increase the pool of fatty acyl-CoA, and heterologous expression of acyl-coenzyme A: diacylglycerol acyltransferase from Acinetobacter baylyi. An optimized fed-batch microbial fermentation of the modified E. coli strain yielded a titer of 922 mg L(-1) FAEEs that consisted primarily of ethyl palmitate, -oleate, -myristate and -palmitoleate.

  20. Purification of a jojoba embryo wax synthase, cloning of its cDNA, and production of high levels of wax in seeds of transgenic arabidopsis.

    Science.gov (United States)

    Lardizabal, K D; Metz, J G; Sakamoto, T; Hutton, W C; Pollard, M R; Lassner, M W

    2000-03-01

    Wax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned. Seed-specific expression of the cDNA in transgenic Arabidopsis conferred high levels of WS activity on developing embryos from those plants. The WS sequence has significant homology with several Arabidopsis open reading frames of unknown function. Wax production in jojoba requires, in addition to WS, a fatty acyl-CoA reductase (FAR) and an efficient fatty acid elongase system that forms the substrates preferred by the FAR. We have expressed the jojoba WS cDNA in Arabidopsis in combination with cDNAs encoding the jojoba FAR and a beta-ketoacyl-CoA synthase (a component of fatty acid elongase) from Lunaria annua. (13)C-Nuclear magnetic resonance analysis of pooled whole seeds from transgenic plants indicated that as many as 49% of the oil molecules in the seeds were waxes. Gas chromatography analysis of transmethylated oil from individual seeds suggested that wax levels may represent up to 70% (by weight) of the oil present in those seeds.

  1. Differential effects of triclosan on the activation of mouse and human peroxisome proliferator-activated receptor alpha.

    Science.gov (United States)

    Wu, Yuanfeng; Wu, Qiangen; Beland, Frederick A; Ge, Peter; Manjanatha, Mugimane G; Fang, Jia-Long

    2014-11-18

    Triclosan is an anti-bacterial agent used in many personal care products, household items, medical devices, and clinical settings. Liver tumors occur in mice exposed to triclosan, a response attributed to peroxisome proliferator-activated receptor alpha (PPARα) activation; however, the effects of triclosan on mouse and human PPARα have not been fully evaluated. We compared the effects of triclosan on mouse and human PPARα using PPARα reporter assays and on downstream events of PPARα activation using mouse hepatoma Hepa1c1c7 cells and human hepatoma HepG2 cells. PPARα transcriptional activity was increased by triclosan in a mouse PPARα reporter assay and decreased in a human PPARα reporter assay. Concentrations of triclosan inhibiting 50% cell growth were similar in both human and mouse hepatoma cells. Western blotting analysis showed that triclosan increased acyl-coenzyme A oxidase (ACOX1), a PPARα target, in Hepa1c1c7 cells but decreased the level in HepG2 cells. Treatment of Hepa1c1c7 cells with triclosan enhanced DNA synthesis and suppressed transforming growth factor beta-mediated apoptosis. This did not occur in HepG2 cells. These data demonstrate that triclosan had similar cytotoxicity in Hepa1c1c7 and HepG2 cells, but differential effects on the activation of PPARα, the expression of ACOX1, and downstream events including DNA synthesis and apoptosis. Published by Elsevier Ireland Ltd.

  2. Novel O-palmitolylated beta-E1 subunit of pyruvate dehydrogenase is phosphorylated during ischemia/reperfusion injury

    Directory of Open Access Journals (Sweden)

    Barr Amy J

    2010-07-01

    Full Text Available Abstract Background During and following myocardial ischemia, glucose oxidation rates are low and fatty acids dominate as a source of oxidative metabolism. This metabolic phenotype is associated with contractile dysfunction during reperfusion. To determine the mechanism of this reliance on fatty acid oxidation as a source of ATP generation, a functional proteomics approach was utilized. Results 2-D gel electrophoresis of mitochondria from working rat hearts subjected to 25 minutes of global no flow ischemia followed by 40 minutes of aerobic reperfusion identified 32 changes in protein abundance compared to aerobic controls. Of the five proteins with the greatest change in abundance, two were increased (long chain acyl-coenzyme A dehydrogenase (48 ± 1 versus 39 ± 3 arbitrary units, n = 3, P In silico analysis identified the putative kinases as the insulin receptor kinase for the more basic form and protein kinase Cζ or protein kinase A for the more acidic form. These modifications of pyruvate dehydrogenase are associated with a 35% decrease in glucose oxidation during reperfusion. Conclusions Cardiac ischemia/reperfusion induces significant changes to a number of metabolic proteins of the mitochondrial proteome. In particular, ischemia/reperfusion induced the post-translational modification of pyruvate dehydrogenase, the rate-limiting step of glucose oxidation, which is associated with a 35% decrease in glucose oxidation during reperfusion. Therefore these post-translational modifications may have important implications in the regulation of myocardial energy metabolism.

  3. Electrochemical Characterization of Escherichia coli Adaptive Response Protein AidB

    Directory of Open Access Journals (Sweden)

    Sean J. Elliott

    2012-12-01

    Full Text Available When exposed to known DNA-damaging alkylating agents, Escherichia coli cells increase production of four DNA repair enzymes: Ada, AlkA, AlkB, and AidB. The role of three enzymes (Ada, AlkA, and AlkB in repairing DNA lesions has been well characterized, while the function of AidB is poorly understood. AidB has a distinct cofactor that is potentially related to the elusive role of AidB in adaptive response: a redox active flavin adenine dinucleotide (FAD. In this study, we report the thermodynamic redox properties of the AidB flavin for the first time, both for free protein and in the presence of potential substrates. We find that the midpoint reduction potential of the AidB flavin is within a biologically relevant window for redox chemistry at −181 mV, that AidB significantly stabilizes the flavin semiquinone, and that small molecule binding perturbs the observed reduction potential. Our electrochemical results combined with structural analysis allow for fresh comparisons between AidB and the homologous acyl-coenzyme A dehydrogenase (ACAD family of enzymes. AidB exhibits several discrepancies from ACADs that suggest a novel catalytic mechanism distinct from that of the ACAD family enzymes.

  4. Improving fatty acid availability for bio-hydrocarbon production in Escherichia coli by metabolic engineering.

    Directory of Open Access Journals (Sweden)

    Fengming Lin

    Full Text Available Previous studies have demonstrated the feasibility of producing fatty-acid-derived hydrocarbons in Escherichia coli. However, product titers and yields remain low. In this work, we demonstrate new methods for improving fatty acid production by modifying central carbon metabolism and storing fatty acids in triacylglycerol. Based on suggestions from a computational model, we deleted seven genes involved in aerobic respiration, mixed-acid fermentation, and glyoxylate bypass (in the order of cyoA, nuoA, ndh, adhE, dld, pta, and iclR to modify the central carbon metabolic/regulatory networks. These gene deletions led to increased total fatty acids, which were the highest in the mutants containing five or six gene knockouts. Additionally, when two key enzymes in the fatty acid biosynthesis pathway were over-expressed, we observed further increase in strain △cyoA△adhE△nuoA△ndh△pta△dld, leading to 202 mg/g dry cell weight of total fatty acids, ~250% of that in the wild-type strain. Meanwhile, we successfully introduced a triacylglycerol biosynthesis pathway into E. coli through heterologous expression of wax ester synthase/acyl-coenzyme:diacylglycerol acyltransferase (WS/DGAT enzymes. The added pathway improved both the amount and fuel quality of the fatty acids. These new metabolic engineering strategies are providing promising directions for future investigation.

  5. Lipid storage myopathies.

    Science.gov (United States)

    Bruno, Claudio; Dimauro, Salvatore

    2008-10-01

    The aim of this review is to provide an update on disorders of lipid metabolism affecting skeletal muscle exclusively or predominantly and to summarize recent clinical, genetic, and therapeutic studies in this field. Over the past 5 years, new clinical phenotypes and genetic loci have been described, unusual pathogenic mechanisms have been elucidated, and novel pharmacological approaches have been developed. At least one genetic defect responsible for the myopathic form of CoQ10 deficiency has been identified, causing a disorder that is allelic with the late-onset riboflavine-responsive form of multiple acyl-coenzyme A dehydrogenation deficiency. Novel mechanisms involved in the lipolytic breakdown of cellular lipid depots have been described and have led to the identification of genes and mutations responsible for multisystemic neutral lipid storage disorders, characterized by accumulation of triglyceride in multiple tissues, including muscle. Defects in lipid metabolism can affect either the mitochondrial transport and oxidation of exogenous fatty acid or the catabolism of endogenous triglycerides. These disorders impair energy production and almost invariably involve skeletal muscle, causing progressive myopathy with muscle weakness, or recurrent acute episodes of rhabdomyolysis triggered by exercise, fasting, or infections. Clinical and genetic characterization of these disorders has important implications both for accurate diagnostic approach and for development of therapeutic strategies.

  6. A diagnostic algorithm for metabolic myopathies.

    Science.gov (United States)

    Berardo, Andres; DiMauro, Salvatore; Hirano, Michio

    2010-03-01

    Metabolic myopathies comprise a clinically and etiologically diverse group of disorders caused by defects in cellular energy metabolism, including the breakdown of carbohydrates and fatty acids to generate adenosine triphosphate, predominantly through mitochondrial oxidative phosphorylation. Accordingly, the three main categories of metabolic myopathies are glycogen storage diseases, fatty acid oxidation defects, and mitochondrial disorders due to respiratory chain impairment. The wide clinical spectrum of metabolic myopathies ranges from severe infantile-onset multisystemic diseases to adult-onset isolated myopathies with exertional cramps. Diagnosing these diverse disorders often is challenging because clinical features such as recurrent myoglobinuria and exercise intolerance are common to all three types of metabolic myopathy. Nevertheless, distinct clinical manifestations are important to recognize as they can guide diagnostic testing and lead to the correct diagnosis. This article briefly reviews general clinical aspects of metabolic myopathies and highlights approaches to diagnosing the relatively more frequent subtypes (Fig. 1). Fig. 1 Clinical algorithm for patients with exercise intolerance in whom a metabolic myopathy is suspected. CK-creatine kinase; COX-cytochrome c oxidase; CPT-carnitine palmitoyl transferase; cyt b-cytochrome b; mtDNA-mitochondrial DNA; nDNA-nuclear DNA; PFK-phosphofructokinase; PGAM-phosphoglycerate mutase; PGK-phosphoglycerate kinase; PPL-myophosphorylase; RRF-ragged red fibers; TFP-trifunctional protein deficiency; VLCAD-very long-chain acyl-coenzyme A dehydrogenase.

  7. Statins Activate Human PPAR Promoter and Increase PPAR mRNA Expression and Activation in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Makoto Seo

    2008-01-01

    Full Text Available Statins increase peroxisome proliferator-activated receptor (PPAR mRNA expression, but the mechanism of this increased PPAR production remains elusive. To examine the regulation of PPAR production, we examined the effect of 7 statins (atorvastatin, cerivastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin on human PPAR promoter activity, mRNA expression, nuclear protein levels, and transcriptional activity. The main results are as follows. (1 Majority of statins enhanced PPAR promoter activity in a dose-dependent manner in HepG2 cells transfected with the human PPAR promoter. This enhancement may be mediated by statin-induced HNF-4. (2 PPAR mRNA expression was increased by statin treatment. (3 The PPAR levels in nuclear fractions were increased by statin treatment. (4 Simvastatin, pravastatin, and cerivastatin markedly enhanced transcriptional activity in 293T cells cotransfected with acyl-coenzyme A oxidase promoter and PPAR/RXR expression vectors. In summary, these data demonstrate that PPAR production and activation are upregulated through the PPAR promoter activity by statin treatment.

  8. Improving fatty acid availability for bio-hydrocarbon production in Escherichia coli by metabolic engineering.

    Science.gov (United States)

    Lin, Fengming; Chen, Yu; Levine, Robert; Lee, Kilho; Yuan, Yingjin; Lin, Xiaoxia Nina

    2013-01-01

    Previous studies have demonstrated the feasibility of producing fatty-acid-derived hydrocarbons in Escherichia coli. However, product titers and yields remain low. In this work, we demonstrate new methods for improving fatty acid production by modifying central carbon metabolism and storing fatty acids in triacylglycerol. Based on suggestions from a computational model, we deleted seven genes involved in aerobic respiration, mixed-acid fermentation, and glyoxylate bypass (in the order of cyoA, nuoA, ndh, adhE, dld, pta, and iclR) to modify the central carbon metabolic/regulatory networks. These gene deletions led to increased total fatty acids, which were the highest in the mutants containing five or six gene knockouts. Additionally, when two key enzymes in the fatty acid biosynthesis pathway were over-expressed, we observed further increase in strain △cyoA△adhE△nuoA△ndh△pta△dld, leading to 202 mg/g dry cell weight of total fatty acids, ~250% of that in the wild-type strain. Meanwhile, we successfully introduced a triacylglycerol biosynthesis pathway into E. coli through heterologous expression of wax ester synthase/acyl-coenzyme:diacylglycerol acyltransferase (WS/DGAT) enzymes. The added pathway improved both the amount and fuel quality of the fatty acids. These new metabolic engineering strategies are providing promising directions for future investigation.

  9. Taurine reduces the secretion of apolipoprotein B100 and lipids in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Nagao Koji

    2008-10-01

    Full Text Available Abstract Background Higher concentrations of serum lipids and apolipoprotein B100 (apoB are major individual risk factors of atherosclerosis and coronary heart disease. Therefore ameliorative effects of food components against the diseases are being paid attention in the affluent countries. The present study was undertaken to investigate the effect of taurine on apoB secretion and lipid metabolism in human liver model HepG2 cells. Results The results demonstrated that an addition of taurine to the culture media reduces triacylglycerol (TG-mass in the cells and the medium. Similarly, cellular cholesterol-mass was decreased. Taurine inhibited the incorporation of [14C] oleate into cellular and medium TG, suggesting the inhibition of TG synthesis. In addition, taurine reduced the synthesis of cellular cholesterol ester and its secretion, suggesting the inhibition of acyl-coenzyme A:cholesterol acyltransferase activity. Furthermore, taurine reduced the secretion of apoB, which is a major protein component of very low-density lipoprotein. Conclusion This is a first report to demonstrate that taurine inhibits the secretion of apoB from HepG2 cells.

  10. Research for Developing Renewable Biofuels from Algae

    Energy Technology Data Exchange (ETDEWEB)

    Black, Paul N. [Univ. of Nebraska, Lincoln, NE (United States)

    2012-12-15

    Task A. Expansion of knowledge related to lipid production and secretion in algae A.1 Lipid biosynthesis in target algal species; Systems biology approaches are being used in combination with recent advances in Chlorella and Chlamydomonas genomics to address lipid accumulation in response to defined nutrient regimes. The UNL Algal Group continues screening additional species of Chlorella and other naturally occurring algae for those with optimal triglyceride production; Of the strains examined by the DOE's Aquatic Species Program, green algae, several species of Chlorella represent the largest group from which oleaginous candidates have been identified; A.1.1. Lipid profiling; Neutral lipid accumulation is routinely monitored by Nile red and BODIPY staining using high throughput strategies to screen for naturally occurring algae that accumulate triglyceride. These strategies complement those using spectrofluorometry to quantify lipid accumulation; Neutral lipid accumulation is routinely monitored by high performance thin-layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) of lipid extracts in conjunction with; Carbon portioning experiments have been completed and the data currently are being analyzed and prepared for publication; Methods in the Black lab were developed to identify and quantify triacylglycerol (TAG), major membrane lipids [diacylglycerol trimethylhomoserine, phosphatidylethanolamine and chloroplast glycolipids], biosynthetic intermediates such as diacylglycerol, phosphatidic acid and lysophospholipids and different species of acyl-coenzyme A (acyl CoA).

  11. De novo biosynthesis of biodiesel by Escherichia coli in optimized fed-batch cultivation.

    Directory of Open Access Journals (Sweden)

    Yangkai Duan

    Full Text Available Biodiesel is a renewable alternative to petroleum diesel fuel that can contribute to carbon dioxide emission reduction and energy supply. Biodiesel is composed of fatty acid alkyl esters, including fatty acid methyl esters (FAMEs and fatty acid ethyl esters (FAEEs, and is currently produced through the transesterification reaction of methanol (or ethanol and triacylglycerols (TAGs. TAGs are mainly obtained from oilseed plants and microalgae. A sustainable supply of TAGs is a major bottleneck for current biodiesel production. Here we report the de novo biosynthesis of FAEEs from glucose, which can be derived from lignocellulosic biomass, in genetically engineered Escherichia coli by introduction of the ethanol-producing pathway from Zymomonas mobilis, genetic manipulation to increase the pool of fatty acyl-CoA, and heterologous expression of acyl-coenzyme A: diacylglycerol acyltransferase from Acinetobacter baylyi. An optimized fed-batch microbial fermentation of the modified E. coli strain yielded a titer of 922 mg L(-1 FAEEs that consisted primarily of ethyl palmitate, -oleate, -myristate and -palmitoleate.

  12. Acute Testosterone Deficiency Alters Adipose Tissue Fatty Acid Storage.

    Science.gov (United States)

    Santosa, Sylvia; Bush, Nikki C; Jensen, Michael D

    2017-08-01

    Although the long-term effects of testosterone on adipose tissue lipid metabolism in men have been defined, the short-term regulation of these effects is not well understood. We examined the effects of acute testosterone withdrawal on subcutaneous abdominal and femoral adipose tissue fatty acid (FA) storage and cellular mechanisms. This was a prospective, randomized trial. Mayo Clinic Clinical Research Unit. Thirty-two male volunteers ages 18 to 50 participated in these studies. Volunteers were randomized to receive (1) no treatment (control), (2) injections (7.5 mg) of Lupron®, or (3) Lupron and testosterone (L+T) replacement for 49 days, resulting in 4 weeks of sex steroid suppression in the Lupron group. We measured body composition, fat cell size, adipose tissue meal FA and direct free FA storage, lipoprotein lipase (LPL), acyl coenzyme A synthetase (ACS), diacylglycerol acyltransferase activities, and CD36 content. Compared with control and L+T groups, acute testosterone deficiency resulted in greater femoral adipose tissue meal FA storage rates, fasting and fed LPL activity, and ACS activity. These results suggest that in men, testosterone plays a tonic role in restraining FA storage in femoral adipose tissue via suppression of LPL and ACS activities. FA storage mechanisms in men appear sensitive to short-term changes in testosterone concentrations.

  13. Spectrum analysis of common inherited metabolic diseases in Chinese patients screened and diagnosed by tandem mass spectrometry.

    Science.gov (United States)

    Han, Lianshu; Han, Feng; Ye, Jun; Qiu, Wenjuan; Zhang, Huiwen; Gao, Xiaolan; Wang, Yu; Ji, Wenjun; Gu, Xuefan

    2015-03-01

    Information concerning inherited metabolic diseases in China is scarce. We investigated the prevalence and age distributions of amino acid, organic acid, and fatty acid oxidation disorders in Chinese patients. Blood levels of amino acids and acylcarnitines (tandem mass spectrometry) were measured in 18,303 patients with suspected inherited metabolic diseases. Diagnosis was based on clinical features, blood levels of amino acids or acylcarnitines, urinary organic acid levels (gas chromatography-mass spectrometry), and (in some) gene mutation tests. Inherited metabolic diseases were confirmed in 1,135 patients (739 males, 396 females). Median age was 12 months (1 day to 59 years). There were 28 diseases: 12 amino acid disorders (580 patients, 51.1%), with hyperphenylalaninemia (HPA) being the most common; nine organic acidemias (408 patients, 35.9%), with methylmalonic acidemia (MMA) as the most common; and seven fatty acid oxidation defects (147 patients, 13.0%), with multiple acyl-coenzyme A dehydrogenase deficiency (MADD) being the most common. Onset was mainly at 1-6 months for citrin deficiency, 0-6 months for MMA, and in newborns for ornithine transcarbamylase deficiency (OTCD). HPA was common in patients aged 1-3 years, and MADD was common in patients >18 years. In China, HPA, citrin deficiency, MMA, and MADD are the most common inherited disorders, particularly in newborns/infants. © 2014 Wiley Periodicals, Inc.

  14. Saccharomyces cerevisiae Atf1p is an alcohol acetyltransferase and a thioesterase in vitro.

    Science.gov (United States)

    Nancolas, Bethany; Bull, Ian D; Stenner, Richard; Dufour, Virginie; Curnow, Paul

    2017-06-01

    The alcohol-O-acyltransferases are bisubstrate enzymes that catalyse the transfer of acyl chains from an acyl-coenzyme A (CoA) donor to an acceptor alcohol. In the industrial yeast Saccharomyces cerevisiae this reaction produces acyl esters that are an important influence on the flavour of fermented beverages and foods. There is also a growing interest in using acyltransferases to produce bulk quantities of acyl esters in engineered microbial cell factories. However, the structure and function of the alcohol-O-acyltransferases remain only partly understood. Here, we recombinantly express, purify and characterize Atf1p, the major alcohol acetyltransferase from S. cerevisiae. We find that Atf1p is promiscuous with regard to the alcohol cosubstrate but that the acyltransfer activity is specific for acetyl-CoA. Additionally, we find that Atf1p is an efficient thioesterase in vitro with specificity towards medium-chain-length acyl-CoAs. Unexpectedly, we also find that mutating the supposed catalytic histidine (H191) within the conserved HXXXDG active site motif only moderately reduces the thioesterase activity of Atf1p. Our results imply a role for Atf1p in CoA homeostasis and suggest that engineering Atf1p to reduce the thioesterase activity could improve product yields of acetate esters from cellular factories. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd.

  15. Designing and Creating a Synthetic Omega Oxidation Pathway inSaccharomyces cerevisiaeEnables Production of Medium-Chain α, ω-Dicarboxylic Acids.

    Science.gov (United States)

    Han, Li; Peng, Yanfeng; Zhang, Yuangyuan; Chen, Wujiu; Lin, Yuping; Wang, Qinhong

    2017-01-01

    Medium-chain (C8-C14) α, ω-dicarboxylic acids (α, ω-DCAs), which have numerous applications as raw materials for producing various commodities and polymers in chemical industry, are mainly produced from chemical or microbial conversion of petroleum-derived alkanes or plant-derived fatty acids at present. Recently, significant attention has been gained to microbial production of medium-chain α, ω-DCAs from simple renewable sugars. Here, we designed and created a synthetic omega oxidation pathway in Saccharomyces cerevisiae to produce C10 and C12 α, ω-DCAs from renewable sugars and fatty acids by introducing a heterogeneous cytochrome P450 CYP94C1 and cytochrome reductase ATR1. Furthermore, the deletion of fatty acyl-CoA synthetase genes FAA1 and FAA4 increased the production of medium-chain α, ω-DCAs from 4.690 ± 0.088 mg/L to 12.177 ± 0.420 mg/L and enabled the production of C14 and C16 α, ω-DCAs at low percentage. But blocking β-oxidation pathway by deleting fatty-acyl coenzyme A oxidase gene POX1 and overexpressing different thioesterase genes had no significant impact on the production and the composition of α, ω-dicarboxylic acids. Overall, our study indicated the potential of microbial production of medium-chain α, ω-DCAs from renewable feedstocks using engineered yeast.

  16. Cyclic vomiting syndrome masking a fatal metabolic disease.

    LENUS (Irish Health Repository)

    Fitzgerald, Marianne

    2013-05-01

    Disorders of fatty acid oxidation are rare but can be fatal. Hypoglycaemia with acidosis is a cardinal feature. Cases may present during early childhood or can be delayed into adolescence or beyond. We present a case of multiple acyl-coenzyme A dehydrogenase deficiency (MADD), an extremely rare disorder of fatty acid oxidation. Our 20-year-old patient presented with cardiovascular collapse, raised anion gap metabolic acidosis and non-ketotic hypoglycaemia. She subsequently developed multi-organ failure and sadly died. She had a previous diagnosis of cyclic vomiting syndrome (CVS) for more than 10 years, warranting frequent hospital admissions. The association between CVS and MADD has been made before though the exact relationship is unclear. All patients with persistent severe CVS should have metabolic investigations to exclude disorders of fatty acid oxidation. In case of non-ketotic hypoglycaemia with acidosis, the patient should be urgently referred to a specialist in metabolic diseases. All practitioners should be aware of these rare disorders as a cause of unexplained acidosis.

  17. Pterostilbene, a dimethyl ether derivative of resveratrol, reduces fat accumulation in rats fed an obesogenic diet.

    Science.gov (United States)

    Gómez-Zorita, Saioa; Fernández-Quintela, Alfredo; Lasa, Arrate; Aguirre, Leixuri; Rimando, Agnes M; Portillo, María P

    2014-08-20

    The current study aimed to demonstrate the effects of pterostilbene in rats fed an obesogenic diet. For this purpose, pterostilbene was administered at doses of 15 mg/kg body weight/day (PT15 group) or 30 mg/kg body weight/day (PT30 group) for 6 weeks. Pterostilbene reduced adipose tissue mass -15.1% (PT15) and -22.9% (PT30). In this tissue, it decreased malic enzyme (-39.4 and -49.5% for PT15 and PT30 groups, respectively) and fatty acid synthase (-45 and -53.4% for PT15 and PT30) activities. Acetyl-CoA carboxylase activity was reduced and AMPK activity was increased only in the PT30 group. In the liver, pterostilbene (PT30) reduced malic enzyme (-29.5%) and glucose-6-P dehydrogenase (-43.2%) activities and increased carnitine palmitoyltransferase-1a (37.5%) and acyl-coenzyme A oxidase (42.5%) activities. This increased oxidative capacity was not associated with increased mitochondriogenesis. Among biochemical serum parameters, only insulin was modified by pterostilbene (-31.6%) in the PT15 group. The amounts of pterostilbene in serum and tissues from rats in the PT30 group were in not all cases 2-fold greater than those found in the PT15 group. In conclusion, pterostilbene shows antiobesity properties due, at least in part, to reduced lipogenesis in adipose tissue and increased fatty acid oxidation in liver.

  18. Exercise and obesity-induced insulin resistance in skeletal muscle

    Directory of Open Access Journals (Sweden)

    Hyo-Bum Kwak

    2013-12-01

    Full Text Available The skeletal muscle in our body is a major site for bioenergetics and metabolism during exercise. Carbohydrates and fats are the primary nutrients that provide the necessary energy required to maintain cellular activities during exercise. The metabolic responses to exercise in glucose and lipid regulation depend on the intensity and duration of exercise. Because of the increasing prevalence of obesity, recent studies have focused on the cellular and molecular mechanisms of obesity-induced insulin resistance in skeletal muscle. Accumulation of intramyocellular lipid may lead to insulin resistance in skeletal muscle. In addition, lipid intermediates (e.g., fatty acyl-coenzyme A, diacylglycerol, and ceramide impair insulin signaling in skeletal muscle. Recently, emerging evidence linking obesity-induced insulin resistance to excessive lipid oxidation, mitochondrial overload, and mitochondrial oxidative stress have been provided with mitochondrial function. This review will provide a brief comprehensive summary on exercise and skeletal muscle metabolism, and discuss the potential mechanisms of obesity-induced insulin resistance in skeletal muscle.

  19. 3,5-Diiodo-L-Thyronine Modifies the Lipid Droplet Composition in a Model of Hepatosteatosis

    Directory of Open Access Journals (Sweden)

    Elena Grasselli

    2014-02-01

    Full Text Available Background/Aims: Fatty acids are the main energy stores and the major membrane components of the cells. In the hepatocyte, fatty acids are esterified to triacylglycerols (TAGs and stored in lipid droplets (LDs. The lipid lowering action of 3,5-diiodo-L-thyronine (T2 on an in vitro model of hepatosteatosis was investigated in terms of fatty acid and protein content of LDs, lipid oxidation and secretion. Methods: FaO cells were exposed to oleate/palmitate, then treated with T2. Results: T2 reduced number and size of LDs, and modified their acyl composition by decreasing the content of saturated (SFA vs monounsaturated (MUFA fatty acids thus reversing the SFA/MUFA ratio. The expression of the LD-associated proteins adipose differentiation-related protein (ADRP, oxidative tissue-enriched PAT protein (OXPAT, and adipose triglyceride lipase (ATGL was increased in ‘steatotic' cells and further up-regulated by T2. Moreover, T2 stimulated the mitochondrial oxidation by up-regulating carnitine-palmitoyl-transferase (CPT1, uncoupling protein 2 (UCP2 and very long-chain acyl-coenzyme A dehydrogenase (VLCAD. Conclusions: T2 leads to mobilization of TAGs from LDs and stimulates mitochondrial oxidative metabolism of fatty acids, in particular of SFAs, and thus enriches of MUFAs the LDs. This action may protect the hepatocyte from excess of SFAs that are more toxic than MUFAs.

  20. Thanks, but No Thanks: Women's Avoidance of Help-Seeking in the Context of a Dependency-Related Stereotype

    Science.gov (United States)

    Wakefield, Juliet R. H.; Hopkins, Nick; Greenwood, Ronni M.

    2012-01-01

    The stereotype that women are dependent on men is a commonly verbalized, potentially damaging aspect of benevolent sexism. We investigated how women may use behavioral disconfirmation of the personal applicability of the stereotype to negotiate such sexism. In an experiment (N = 86), we manipulated female college students' awareness that women may…

  1. On the A-dependence of {sigma}{sub L}/{sigma}{sub T}: Skeletons in the shadow

    Energy Technology Data Exchange (ETDEWEB)

    Milana, J. [Univ. of Maryland, College Park (United States)

    1994-04-01

    A most counter-intuitive dependence in the differential cross-section in the shadowing regime is shown to result from a higher-twist nuclear enhancement in R = {sigma}{sub L}/{sigma}{sub T} which severely complicates the unravelling from present data the corresponding dependence in Q{sup 2} of the nuclear structure functions, F{sub 2}{sup A}(x,Q{sup 2}). Indeed, until precision measurements close this loophole, the extrapolations of the structure functions to either higher Q{sup 2} or other processes (as is necessary to address present data at FNAL or future experiments at RHIC) must be considered problematic. The contribution CEBAF can make in this regard by providing systematic determination of R{sub A}(x, Q{sup 2}) is thus emphasized. The purpose of this talk is to motivate an experiment CEBAF can and should do, especially if upgraded to higher energies. While providing information on nuclear structure that is interesting in itself, the added motivation is that precision results will have important impact on other high-energy experiments involving nuclear targets that have been, and will continue to be done all over the world.

  2. Mcm10 deficiency causes defective-replisome-induced mutagenesis and a dependency on error-free postreplicative repair.

    Science.gov (United States)

    Becker, Jordan R; Nguyen, Hai Dang; Wang, Xiaohan; Bielinsky, Anja-Katrin

    2014-01-01

    Mcm10 is a multifunctional replication factor with reported roles in origin activation, polymerase loading, and replication fork progression. The literature supporting these variable roles is controversial, and it has been debated whether Mcm10 has an active role in elongation. Here, we provide evidence that the mcm10-1 allele confers alterations in DNA synthesis that lead to defective-replisome-induced mutagenesis (DRIM). Specifically, we observed that mcm10-1 cells exhibited elevated levels of PCNA ubiquitination and activation of the translesion polymerase, pol-ζ. Whereas translesion synthesis had no measurable impact on viability, mcm10-1 mutants also engaged in error-free postreplicative repair (PRR), and this pathway promoted survival at semi-permissive conditions. Replication gaps in mcm10-1 were likely caused by elongation defects, as dbf4-1 mutants, which are compromised for origin activation did not display any hallmarks of replication stress. Furthermore, we demonstrate that deficiencies in priming, induced by a pol1-1 mutation, also resulted in DRIM, but not in error-free PRR. Similar to mcm10-1 mutants, DRIM did not rescue the replication defect in pol1-1 cells. Thus, it appears that DRIM is not proficient to fill replication gaps in pol1-1 and mcm10-1 mutants. Moreover, the ability to correctly prime nascent DNA may be a crucial prerequisite to initiate error-free PRR.

  3. Role of the GM1 ganglioside oligosaccharide portion in the TrkA-dependent neurite sprouting in neuroblastoma cells.

    Science.gov (United States)

    Chiricozzi, Elena; Pomè, Diego Yuri; Maggioni, Margherita; Di Biase, Erika; Parravicini, Chiara; Palazzolo, Luca; Loberto, Nicoletta; Eberini, Ivano; Sonnino, Sandro

    2017-12-01

    GM1 ganglioside (II 3 NeuAc-Gg 4 Cer) is known to promote neurite formation in neuroblastoma cells by activating TrkA-MAPK pathway. The molecular mechanism by which GM1 is involved in the neurodifferentiation process is still unknown, however, in vitro and in vivo evidences have suggested that the oligosaccharide portion of this ganglioside could be involved. Here, we report that, similarly to the entire GM1 molecule, its oligosaccharide II 3 NeuAc-Gg 4, rather than its ceramide (Cer) portion is responsible for the neurodifferentiation process by augmenting neurite elongation and increasing the neurofilament protein expression in murine neuroblastoma cells, Neuro2a. Conversely, asialo-GM1, GM2 and GM3 oligosaccharides are not effective in neurite elongation on Neuro2a cells, whereas the effect exerted by the Fuc-GM1 oligosaccharide (IV 2 αFucII 3 Neu5Ac-Gg 4 ) is similar to that exerted by GM1 oligosaccharide. The neurotrophic properties of GM1 oligosaccharide are exerted by activating the TrkA receptor and the following phosphorylation cascade. By photolabeling experiments performed with a nitrophenylazide containing GM1 oligosaccharide, labeled with tritium, we showed a direct interaction between the GM1 oligosaccharide and the extracellular domain of TrkA receptor. Moreover, molecular docking analyses confirmed that GM1 oligosaccharide binds the TrkA-nerve growth factor complex leading to a binding free energy of approx. -11.5 kcal/mol, acting as a bridge able to increase and stabilize the TrkA-nerve growth factor molecular interactions. © 2017 International Society for Neurochemistry.

  4. A relA-dependent regulatory cascade for auto-induction of microbisporicin production in Microbispora corallina.

    Science.gov (United States)

    Fernández-Martínez, Lorena T; Gomez-Escribano, Juan P; Bibb, Mervyn J

    2015-08-01

    Microbisporicin is a potent type I lantibiotic produced by the rare actinomycete Microbispora corallina that is in preclinical trials for the treatment of infections caused by methicillin-resistant isolates of Staphylococcus aureus (MRSA). Analysis of the gene cluster for the biosynthesis of microbisporicin, which contains two unique post-translationally modified residues (5-chlorotryptophan and 3, 4-dihydroxyproline), has revealed an unusual regulatory mechanism that involves a pathway-specific extracytoplasmic function sigma factor (MibX)/anti-sigma factor (MibW) complex and an additional transcriptional regulator MibR. A model for the regulation of microbisporicin biosynthesis derived from transcriptional, mutational and quantitative reverse transcription polymerase chain reaction analyses suggests that MibR, which contains a C-terminal DNA-binding domain found in the LuxR family of transcriptional activators, functions as an essential master regulator to trigger microbisporicin production while MibX and MibW induce feed-forward biosynthesis and producer immunity. Moreover, we demonstrate that initial expression of mibR, and thus microbisporicin production, is dependent on the ppGpp synthetase gene (relA) of M. corallina. In addition, we show that constitutive expression of either of the two positively acting regulatory genes, mibR or mibX, leads to precocious and enhanced microbisporicin production. © 2015 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  5. How (not) to train a dependency parser: The curious case of jackknifing part-of-speech taggers

    DEFF Research Database (Denmark)

    Agic, Zeljko; Schluter, Natalie

    2017-01-01

    In dependency parsing, jackknifing taggers is indiscriminately used as a simple adaptation strategy. Here, we empirically evaluate when and how (not) to use jackknifing in parsing. On 26 languages, we reveal a preference that conflicts with, and surpasses the ubiquitous ten-folding. We show no cl...

  6. Integrating NLP Tools in a Distributed Environment: A Case Study Chaining a Tagger with a Dependency Parser

    OpenAIRE

    Rubino, Francesco; Frontini, Francesca; Quochi, Valeria

    2012-01-01

    The present paper tackles the issue of PoS tag conversion within the framework of a distributed web service platform for the automatic creation of language resources. PoS tagging is now considered a "solved problem"; yet, because of the differences in the tagsets, interchange of the various PoS taggers vailable is still hampered. In this paper we describe the implementation of a PoS-tagged-corpus converter, which is needed for chaining together in a workflow the FreeLing PoS tagger for Italia...

  7. Long-chain acyl-CoA-dependent regulation of gene expression in bacteria, yeast and mammals

    DEFF Research Database (Denmark)

    Black, P N; Færgeman, Nils J.; DiRusso, C C

    2000-01-01

    Saccharomyces cerevisiae, genes encoding peroxisomal proteins are activated in response to exogenously supplied fatty acids. In contrast, growth of yeast cells in media containing exogenous fatty acids results in repression of a number of genes, including that encoding the delta9-fatty acid desaturase (OLE1...

  8. A dependência da política: Fernando Henrique Cardoso e a sociologia no Brasil

    Directory of Open Access Journals (Sweden)

    Afrânio Garcia Jr.

    2004-06-01

    Full Text Available Este artigo analisa a trajetória social, intelectual e profissional de Fernando Henrique Cardoso para entender os diferentes recursos sociais e disposições pessoais utilizados em sua carreira como sociólogo e em suas atividades como especialista da política. Busca demonstrar que os capitais sociais e as disposições responsáveis pelo prestígio como pesquisador e professor de ciências sociais foram distintos dos aplicados no domínio da política, permitindo sua rápida ascensão à presidência da República. Depois de estudar suas origens familiares, focaliza seus investimentos escolares e a escolha do ofício de sociólogo, a carreira promissora sendo bloqueada pelo golpe de 1964. O exílio permitiu a extensão das atividades e o reconhecimento internacional, reinvestidos em novo concurso para a USP; o AI-5 o conduzirá à dupla condição de cientista social e de um dos líderes da frente de oposições aos militares. Por fim, analisa-se a reconversão de seus recursos sociais e pessoais na profissão política.This article analyzes Fernando Henrique Cardoso's social, intellectual and professional trajectory in order to understand the different social resources and personal dispositions carried out in his career as sociologist or in his activities as a professional politician. It seeks to prove that the social capitals and the dispositions that might explain his prestige as researcher and professor of social sciences were very different from those required in the political domain, the ones allowing his fast rise to be the president of the Republic. After having examined his family origins, it focuses his scholar investments and the choice of the sociologist's occupation, a promising career suddenly blocked by the 1964 military coup. The exile encouraged new initiatives and brought him international appraisal, this moment being crowned with his access to the chair of political science at the University of São Paulo; the AI-5 enforced by the military rulers will enable him to assume a double condition, as social scientist and as an important opposition leader facing the military. Finally, it analyzes how he was able to reconvert his social and personal resources into the political profession.

  9. The RecA-Dependent SOS Response Is Active and Required for Processing of DNA Damage during Bacillus subtilis Sporulation.

    Directory of Open Access Journals (Sweden)

    Fernando H Ramírez-Guadiana

    Full Text Available The expression of and role played by RecA in protecting sporulating cells of Bacillus subtilis from DNA damage has been determined. Results showed that the DNA-alkylating agent Mitomycin-C (M-C activated expression of a PrecA-gfpmut3a fusion in both sporulating cells' mother cell and forespore compartments. The expression levels of a recA-lacZ fusion were significantly lower in sporulating than in growing cells. However, M-C induced levels of ß-galactosidase from a recA-lacZ fusion ~6- and 3-fold in the mother cell and forespore compartments of B. subtilis sporangia, respectively. Disruption of recA slowed sporulation and sensitized sporulating cells to M-C and UV-C radiation, and the M-C and UV-C sensitivity of sporangia lacking the transcriptional repair-coupling factor Mfd was significantly increased by loss of RecA. We postulate that when DNA damage is encountered during sporulation, RecA activates the SOS response thus providing sporangia with the repair machinery to process DNA lesions that may compromise the spatio-temporal expression of genes that are essential for efficient spore formation.

  10. Newcastle disease virus employs macropinocytosis and Rab5a-dependent intracellular trafficking to infect DF-1 cells.

    Science.gov (United States)

    Tan, Lei; Zhang, Yuqiang; Zhan, Yuan; Yuan, Yanmei; Sun, Yingjie; Qiu, Xusheng; Meng, Chunchun; Song, Cuiping; Liao, Ying; Ding, Chan

    2016-12-27

    Oncolytic Newcastle disease virus (NDV) reportedly employs direct fusion of the viral envelope with the plasma membrane and caveolae-dependent endocytosis to enter cells. Here, we show that macropinocytosis and clathrin-mediated endocytosis are involved in NDV entry into a galline embryonic fibroblast cell line. Upon specific inhibition of clathrin assembly, GTPase dynamin, Na+/H+ exchangers, Ras-related C3 botulinum toxin substrate 1, p21 activated kinase 1 or protein kinase C, entry of NDV and its propagation were suppressed. NDV entry into cells triggers Rac1-Pak1 signaling and elicits actin rearrangement and plasma membrane ruffling. Moreover, NDV internalization within macropinosomes and trafficking involve Rab5a-positive vesicles. This is the first report demonstrating that NDV utilizes clathrin-mediated endocytosis and macropinocytosis as alternative endocytic pathways to enter cells. These findings shed new light on the molecular mechanisms underlying NDV entry into cells, and provide potential targets for NDV-mediated therapy in cancer.

  11. VeriML: A Dependently-Typed, User-Extensible and Language-Centric Approach to Proof Assistants

    Science.gov (United States)

    2013-01-01

    Nikos, Roula, Yiorgos and their wonderful daughter Zoi, Palmyra, Sotiria and the rest of the Greeks at Yale. The members of the legendary Sixth Flour...the following grammar : P ::= P1 ∧ P2 | P1 ∨ P2 | P1 ⊃ P2 | A Proofs are evidence that certain propositions are valid. We will give precise rules for... grammar extensions; we present examples of the concrete syntax in Table 8.1. Our parser emits concrete syntax trees: these are values of a datatype that

  12. NVP-BKM120 inhibits colon cancer growth via FoxO3a-dependent PUMA induction.

    Science.gov (United States)

    Yang, Shida; Li, Xin; Guan, Wenchang; Qian, Mingqin; Yao, Zhicheng; Yin, Xiaoxue; Zhao, Hongmei

    2017-10-10

    NVP-BKM120, a potent and highly selective PI3K inhibitor, is currently being investigated in phase I/II clinical trials. The mechanisms of action of NVP-BKM120 in colon cancer cells are unclear. In the present study, we investigated how NVP-BKM120 suppresses colon cancer cells growth and potentiates effects of other chemotherapeutic drugs. We found that NVP-BKM120 treatment enhance PUMA induction irrespective of p53 status through the FoxO3a pathway following AKT inhibition. Furthermore, PUMA is required for NVP-BKM120-induced apoptosis in colon cancer cells. In addition, NVP-BKM120 also synergized with 5-Fluorouracil or regorafenib to induce marked apoptosis via PUMA induction. Deficiency of PUMA suppressed apoptosis and antitumor effect of NVP-BKM120 in xenograft model. These results demonstrate a key role of PUMA in mediating the anticancer effects of NVP-BKM120 and suggest that PUMA could be used as an indicator of NVP-BKM120 sensitivity, and also have important implications for it clinical applications.

  13. Myeloid Malignancies with Chromosome 5q Deletions Acquire a Dependency on an Intrachromosomal NF-κB Gene Network

    Directory of Open Access Journals (Sweden)

    Jing Fang

    2014-09-01

    Full Text Available Chromosome 5q deletions (del[5q] are common in high-risk (HR myelodysplastic syndrome (MDS and acute myeloid leukemia (AML; however, the gene regulatory networks that sustain these aggressive diseases are unknown. Reduced miR-146a expression in del(5q HR MDS/AML and miR-146a−/− hematopoietic stem/progenitor cells (HSPCs results in TRAF6/NF-κB activation. Increased survival and proliferation of HSPCs from miR-146alow HR MDS/AML is sustained by a neighboring haploid gene, SQSTM1 (p62, expressed from the intact 5q allele. Overexpression of p62 from the intact allele occurs through NF-κB-dependent feedforward signaling mediated by miR-146a deficiency. p62 is necessary for TRAF6-mediated NF-κB signaling, as disrupting the p62-TRAF6 signaling complex results in cell-cycle arrest and apoptosis of MDS/AML cells. Thus, del(5q HR MDS/AML employs an intrachromosomal gene network involving loss of miR-146a and haploid overexpression of p62 via NF-κB to sustain TRAF6/NF-κB signaling for cell survival and proliferation. Interfering with the p62-TRAF6 signaling complex represents a therapeutic option in miR-146a-deficient and aggressive del(5q MDS/AML.

  14. Subinhibitory Concentrations of Bacteriostatic Antibiotics Induce relA-Dependent and relA-Independent Tolerance to beta-Lactams

    Czech Academy of Sciences Publication Activity Database

    Kudrin, P.; Varik, V.; Oliveira, S. R. A.; Beljantseva, J.; Del Peso Santos, T.; Dzhygyr, I.; Rejman, Dominik; Cava, F.; Tenson, T.; Hauryliuk, V.

    2017-01-01

    Roč. 61, č. 4 (2017), č. článku e02173-16. ISSN 0066-4804 R&D Projects: GA ČR GA15-11711S Institutional support: RVO:61388963 Keywords : beta-lactam * RelA * antibiotics * mupirocin * persistence * ppGpp Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.302, year: 2016 http://aac.asm.org/content/61/4/e02173-16.full

  15. Is a mean machine better than a dependable drive? It’s geared towards your regulatory focus

    Directory of Open Access Journals (Sweden)

    Graham G. Scott

    2012-08-01

    Full Text Available While many studies have investigated the role of message-level valence in persuasive messages (i.e., how positive or negative message content affects attitudes, none of these have examined whether word-level valence can modulate such effects. We investigated whether emotional language used within persuasive messages influenced attitudes and whether the processing of such communications could be modulated by regulatory focus. Using a 2 (Message: Positive, Negative × 2 (Words: Positive, Negative design, participants read car reviews and rated each on a series of semantic differentials and product recommendations. While positive messages were always rated higher than negative ones, the valence of a message’s component words differentially impacted attitudes toward distinct aspects of the product. On promotion-focus features, messages containing negative words produced higher ratings; for prevention-focus aspects, those with positive words resulted in higher ratings. We argue that adopting a prevention- or promotion-focused stance can influence the interpretation of emotion words in relation to overall message comprehension.

  16. A-dependence for the charmed meson production; Dependencia em A para a producao de mesons charmosos

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Gilvan Augusto

    1992-03-01

    A report is presented of a recent direct measurement of the nucleon number ({lambda}) dependence of the production cross sections for the charmed mesons D{sup 0} and D{sup +} using {pi}{sup +-} beams incident on a segmented target of Be, Al, Cu and W. The data derive from the experiment E769 - Hadroproduction of Charm - at Fermilab. The experimental apparatus is described together with the following analysis. Starting from a sample of {approx} 1500 D mesons in the range of O < X{sub F} < 1, the data are found to be well described by the parameterization {sigma}{sub A} = {sigma}{sub O} A{sup {alpha}}, with {alpha} = 0.99 {+-} 0.03. The X{sub F} dependence of {alpha} is examined and the results obtained are compared with those of other experiments and with theoretical expectations based on perturbative QCD and on an EMC like model of nuclear shadowing. (author). 85 refs, 61 figs, 22 tabs.

  17. HDAC Activity Is Required for p65/RelA-Dependent Repression of PPARdelta-Mediated Transactivation in Human Keratinocytes

    DEFF Research Database (Denmark)

    Aarenstrup, Lene; Flindt, Esben Noerregaard; Otkjaer, Kristian

    2008-01-01

    Peroxisome proliferator-activated receptors (PPARs) play a key role in differentiation, inflammation, migration, and survival of epidermal keratinocytes. The NF-kappaB has long been known to play pivotal roles in immune and inflammatory responses, and furthermore NF-kappaB has been implicated in ...

  18. Low molecular weight protein tyrosine phosphatase isoforms regulate breast cancer cells migration through a RhoA dependent mechanism.

    Science.gov (United States)

    Alho, Irina; Costa, Luis; Bicho, Manuel; Coelho, Constança

    2013-01-01

    Low molecular weight protein tyrosine phosphatase (LMW-PTP) has been associated with cell proliferation control through dephosphorylation and inactivation of growth factor receptors such as PDGF-R and EphA2, and with cellular adhesion and migration through p190RhoGap and RhoA. We aim to clarify the role of two main LMW-PTP isoforms in breast cancer tumorigenesis. We used a siRNA-mediated loss-of-function in MDA-MB-435 breast cancer cell line to study the role of the two main LMW-PTP isoforms, fast and slow, in breast cancer tumorigenesis and migration. Our results show that the siRNAs directed against total LMW-PTP and LMW-PTP slow isoform enhanced cell motility in an invasive breast cancer cell line, MDA-MB-435, with no changes in the proliferation and invasive potential of cells. The total LMW-PTP knockdown caused a more pronounced increase of cell migration. Suppression of total LMW-PTP decreased RhoA activation and suppression of the LMW-PTP slow isoform caused a small but significant increase in RhoA activation. We propose that the increase or decrease in RhoA activation induces changes in stress fibers formation and consequently alter the adhesive and migratory potential of cells. These findings suggest that the two main isoforms of LMW-PTP may act differentially, with the fast isoform having a more prominent role in tumor cell migration. In addition, our results highlight functional specificity among LMW-PTP isoforms, suggesting hitherto unknown roles for these proteins in breast cancer biology. Novel therapeutic approaches targeting LMW-PTP, considering the expression of these two isoforms and not LMW-PTP as a whole, should be investigated.

  19. SHMT2 drives glioma cell survival in the tumor microenvironment but imposes a dependence on glycine clearance

    Science.gov (United States)

    Kim, Dohoon; Fiske, Brian P.; Birsoy, Kivanc; Freinkman, Elizaveta; Kami, Kenjiro; Possemato, Richard; Chudnovsky, Yakov; Pacold, Michael E.; Chen, Walter W.; Cantor, Jason R.; Shelton, Laura M.; Gui, Dan Y.; Kwon, Manjae; Ramkissoon, Shakti H.; Ligon, Keith L.; Kang, Seong Woo; Snuderl, Matija; Heiden, Matthew G. Vander; Sabatini, David M.

    2015-01-01

    SUMMARY Cancer cells adapt their metabolic processes to support rapid proliferation, but less is known about how cancer cells alter metabolism to promote cell survival in a poorly vascularized tumor microenvironment1–3. Here, we identify a key role for serine and glycine metabolism in the survival of brain cancer cells within the ischemic zones of gliomas. In human glioblastoma multiforme (GBM), mitochondrial serine hydroxymethyltransferase (SHMT2) and glycine decarboxylase (GLDC) are highly expressed in the pseudopalisading cells that surround necrotic foci. We find that SHMT2 activity limits that of pyruvate kinase (PKM2) and reduces oxygen consumption, eliciting a metabolic state that confers a profound survival advantage to cells in poorly vascularized tumor regions. GLDC inhibition impairs cells with high SHMT2 levels as the excess glycine not metabolized by GLDC can be converted to the toxic molecules aminoacetone and methylglyoxal. Thus, SHMT2 is required for cancer cells to adapt to the tumor environment, but also renders these cells sensitive to glycine cleavage system inhibition. PMID:25855294

  20. Utilization of dE/dx approx E sup n /a dependence for DELTA E - E-spectrometer calibration

    CERN Document Server

    Gorpinich, O K; Jachmenov, O O

    2002-01-01

    The method of calibration of DELTA E - E-spectrometers by the use of known empiric form dE/dx approx E sup n /a which describes the specific energy loss of charge particles in the matter for energy calibration of DELTA E - E-spectrometer was designed.

  1. Ghrelin Partially Protects Against Cisplatin-Induced Male Murine Gonadal Toxicity in a GHSR-1a-Dependent Manner1

    Science.gov (United States)

    Whirledge, Shannon D.; Garcia, Jose M.; Smith, Roy G.; Lamb, Dolores J.

    2015-01-01

    ABSTRACT The chemotherapeutic drug cisplatin causes a number of dose-dependent side effects, including cachexia and testicular damage. Patients receiving a high cumulative dose of cisplatin may develop permanent azoospermia and subsequent infertility. Thus, the development of chemotherapeutic regimens with the optimal postsurvival quality of life (fertility) is of high importance. This study tested the hypothesis that ghrelin administration can prevent or minimize cisplatin-induced testicular damage and cachexia. Ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR-1a), are expressed and function in the testis. Targeted deletion of ghrelin, or its receptor, significantly increases the rate of cell death in the testis, suggesting a protective role. Intraperitoneal administration of vehicle, ghrelin, or cisplatin alone or in combination with ghrelin, in cycles of 9 or 18 days, to adult male C57Bl/6 mice was performed. Body weight was measured daily and testicular and epididymal weight, sperm density and motility, testicular histology, and testicular cell death were analyzed at the time of euthanization. Ghrelin coadministration decreased the severity of cisplatin-induced cachexia and gonadal toxicity. Body, testicular, and epididymal weights significantly increased as testicular cell death decreased with ghrelin coadministration. The widespread damage to the seminiferous epithelium induced by cisplatin administration was less severe in mice simultaneously treated with ghrelin. Furthermore, ghrelin diminished the deleterious effects of cisplatin on testis and body weight homeostasis in wild-type but not Ghsr−/− mice, showing that ghrelin's actions are mediated via GHSR. Ghrelin or more stable GHSR agonists potentially offer a novel therapeutic approach to minimize the testicular damage that occurs after gonadotoxin exposure. PMID:25631345

  2. Mass-metallicity relation explored with CALIFA I. Is there a dependence on the star-formation rate?

    Czech Academy of Sciences Publication Activity Database

    Sánchez, Sebastián F.; Rosales-Ortega, F.F.; Jungwiert, Bruno; Iglesias-Paramo, J.; Vílchez, J.M.; Marino, R.A.; Walcher, C.J.; Husemann, B.; Mast, D.; Monreal-Ibero, A.

    2013-01-01

    Roč. 554, June (2013), A58/1-A58/19 ISSN 0004-6361 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100031201; Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100031241 Program:M Institutional support: RVO:67985815 Keywords : galaxies * ISM * undamental parameters Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.479, year: 2013

  3. pSymA-Dependent Mobilization of the Sinorhizobium meliloti pSymB Megaplasmid ▿ †

    Science.gov (United States)

    Blanca-Ordóñez, Helena; Oliva-García, Juan J.; Pérez-Mendoza, Daniel; Soto, María J.; Olivares, José; Sanjuán, Juan; Nogales, Joaquina

    2010-01-01

    Sinorhizobium meliloti 1021 carries two megaplasmids, pSymA of 1,354 kb and pSymB of 1,683 kb, which are essential in establishing symbiosis with its legume hosts and important for bacterial fitness in the rhizosphere. We have previously shown that pSymA is self-transmissible and that its conjugal functions are regulated by the transcriptional repressor RctA. Here, we show conjugal transfer of pSymB as an in trans mobilization event that requires the type IV secretion system encoded by pSymA. pSymB carries a functional oriT and an adjacent relaxase gene, traA2, that is also transcriptionally repressed by rctA. Both symbiotic megaplasmids would require the relaxase genes in cis with their respective oriTs to achieve the highest transfer efficiencies. PMID:20889746

  4. Opioid withdrawal increases transient receptor potential vanilloid 1 activity in a protein kinase A-dependent manner.

    Science.gov (United States)

    Spahn, Viola; Fischer, Oliver; Endres-Becker, Jeannette; Schäfer, Michael; Stein, Christoph; Zöllner, Christian

    2013-04-01

    Hyperalgesia is a cardinal symptom of opioid withdrawal. The transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated ion channel expressed on sensory neurons responding to noxious heat, protons, and chemical stimuli such as capsaicin. TRPV1 can be inhibited via μ-opioid receptor (MOR)-mediated reduced activity of adenylyl cyclases (ACs) and decreased cyclic adenosine monophosphate (cAMP) levels. In contrast, opioid withdrawal following chronic activation of MOR uncovers AC superactivation and subsequent increases in cAMP and protein kinase A (PKA) activity. Here we investigated (1) whether an increase in cAMP during opioid withdrawal increases the activity of TRPV1 and (2) how opioid withdrawal modulates capsaicin-induced nocifensive behavior in rats. We applied whole-cell patch clamp, microfluorimetry, cAMP assays, radioligand binding, site-directed mutagenesis, and behavioral experiments. Opioid withdrawal significantly increased cAMP levels and capsaicin-induced TRPV1 activity in both transfected human embryonic kidney 293 cells and dissociated dorsal root ganglion (DRG) neurons. Inhibition of AC and PKA, as well as mutations of the PKA phosphorylation sites threonine 144 and serine 774, prevented the enhanced TRPV1 activity. Finally, capsaicin-induced nocifensive behavior was increased during opioid withdrawal in vivo. In summary, our results demonstrate an increased activity of TRPV1 in DRG neurons as a new mechanism contributing to opioid withdrawal-induced hyperalgesia. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  5. Proteomic analysis of formalin-fixed paraffin-embedded glomeruli suggests depletion of glomerular filtration barrier proteins in two-kidney, one-clip hypertensive rats.

    Science.gov (United States)

    Finne, Kenneth; Vethe, Heidrun; Skogstrand, Trude; Leh, Sabine; Dahl, Tone D; Tenstad, Olav; Berven, Frode S; Reed, Rolf K; Vikse, Bjørn Egil

    2014-12-01

    It is well known that hypertension may cause glomerular damage, but the molecular mechanisms involved are still incompletely understood. In the present study, we used formalin-fixed paraffin-embedded (FFPE) tissue to investigate changes in the glomerular proteome in the non-clipped kidney of two-kidney one-clip (2K1C) hypertensive rats, with special emphasis on the glomerular filtration barrier. 2K1C hypertension was induced in 6-week-old Wistar Hannover rats (n = 6) that were sacrificed 23 weeks later and compared with age-matched sham-operated controls (n = 6). Tissue was stored in FFPE tissue blocks and later prepared on tissue slides for laser microdissection. Glomeruli without severe morphological damage were isolated, and the proteomes were analysed using liquid chromatography-tandem mass spectrometry. 2K1C glomeruli showed reduced abundance of proteins important for slit diaphragm complex, such as nephrin, podocin and neph1. The podocyte foot process had a pattern of reduced abundance of transmembrane proteins but unchanged abundances of the podocyte cytoskeletal proteins synaptopodin and α-actinin-4. Lower abundance of important glomerular basement membrane proteins was seen. Possible glomerular markers of damage with increased abundance in 2K1C were transgelin, desmin and acyl-coenzyme A thioesterase 1. Microdissection and tandem mass spectrometry could be used to investigate the proteome of isolated glomeruli from FFPE tissue. Glomerular filtration barrier proteins had reduced abundance in the non-clipped kidney of 2K1C hypertensive rats. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA.

  6. ACBD2/ECI2-Mediated Peroxisome-Mitochondria Interactions in Leydig Cell Steroid Biosynthesis

    Science.gov (United States)

    Fan, Jinjiang; Li, Xinlu; Issop, Leeyah; Culty, Martine

    2016-01-01

    Fatty acid metabolism and steroid biosynthesis are 2 major pathways shared by peroxisomes and mitochondria. Both organelles are in close apposition to the endoplasmic reticulum, with which they communicate via interorganelle membrane contact sites to promote cellular signaling and the exchange of ions and lipids. To date, no convincing evidence of the direct contact between peroxisomes and mitochondria was reported in mammalian cells. Hormone-induced, tightly controlled steroid hormone biosynthesis requires interorganelle interactions. Using immunofluorescent staining and live-cell imaging, we found that dibutyryl-cAMP treatment of MA-10 mouse tumor Leydig cells rapidly induces peroxisomes to approach mitochondria and form peroxisome-mitochondrial contact sites/fusion, revealed by the subcellular distribution of the endogenous acyl-coenzyme A-binding domain (ACBD)2/ECI2 isoform A generated by alternative splicing, and further validated using a proximity ligation assay. This event occurs likely via a peroxisome-like structure, which is mediated by peroxisomal and mitochondrial matrix protein import complexes: peroxisomal import receptor peroxisomal biogenesis factor 5 (PEX5), and the mitochondrial import receptor subunit translocase of outer mitochondrial membrane 20 homolog (yeast) protein. Similar results were obtained using the mLTC-1 mouse tumor Leydig cells. Ectopic expression of the ACBD2/ECI2 isoform A in MA-10 cells led to increased basal and hormone-stimulated steroid formation, indicating that ACBD2/ECI2-mediated peroxisomes-mitochondria interactions favor in the exchange of metabolites and/or macromolecules between these 2 organelles in support of steroid biosynthesis. Considering the widespread occurrence of the ACBD2/ECI2 protein, we propose that this protein might serve as a tool to assist in understanding the contact between peroxisomes and mitochondria. PMID:27167610

  7. Corn gluten hydrolysate and capsaicin have complimentary actions on body weight reduction and lipid-related genes in diet-induced obese rats.

    Science.gov (United States)

    Mun, Joo-Mi; Ok, Hyang Mok; Kwon, Oran

    2014-05-01

    The aim of this study was to test the hypothesis that a combination of corn gluten hydrolysate (CGH) and capsaicin may have an additive or synergistic effect on body weight reduction. For 13 weeks, male Sprague-Dawley rats were provided a diet to induce obesity. Afterward, the rats were randomly divided into 5 dietary groups: the normal control (n = 5), the high-fat control (n = 8), the high-fat diet (HFD) containing 35% CGH (n = 7), the HFD containing 0.02% capsaicin (HF-P) (n = 8), and the HFD containing both CGH and capsaicin (HF-CP) (n = 7) for an additional 4 weeks. Administration of CGH plus capsaicin, along with a HFD, led to significant decreases in body weight, fat mass, lipids in the liver, and plasma leptin as well as increases in plasma adiponectin. The pattern of gene expression was different in each target organ. In the liver, up-regulation of peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1α, and acyl-coenzyme A oxidase was found in the HF-CP group. In contrast, down-regulation of peroxisome proliferator-activated receptor γ was found in both the HFD containing 35% CGH and HF-CP groups. In skeletal muscle, up-regulation of insulin receptor and uncoupling protein 3 was found in the HF-P group only, whereas up-regulation of the glucose transporter 4 gene was observed in both the HF-CP and HF-P groups. In adipose tissue, up-regulation of peroxisome proliferator-activated receptor γ and hormone-sensitive lipase was only found in the HF-CP group. In summary, this study suggests that CGH and capsaicin perform complementary actions on food intake, lipid metabolism, and insulin sensitivity by a coordinated control of energy metabolism in the liver, adipose tissue, and skeletal muscle, thus exerting an additive effect on body weight reduction. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Polycistronic mRNAs code for polypeptides of the Vibrio harveyi luminescence system

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, C.M.; Graham, A.D.; Boylan, M.; Evans, J.F.; Hasel, K.W.; Meighen, E.A.; Graham, A.F.

    1985-03-01

    DNA coding for the ..cap alpha.. and ..beta.. subunits of Vibrio harveyi luciferase, the luxA and luxB genes, and the adjoining chromosomal regions on both sides of these genes (total of 18 kilobase pairs) was cloned into Escherichia coli. Using labeled DNA coding for the ..cap alpha.. subunit as a hybridization probe, the authors identified a set of polycistronic mRNAs (2.6, 4, 7, and 8 kilobases) by Northern blotting; the most prominent of these was the one 4 kilobases long. This set of mRNAs was induced during the development of bioluminescence in V. harveyi. Furthermore, the same set of mRNAs was synthesized in E. coli by a recombinant plasmid that contained a 12-kilobase pair length of V. harveyi DNA and expressed the genes for the luciferase subunits. A cloned DNA segment corresponding to the major 4-kilobase mRNA coded for the ..cap alpha.. and ..beta.. subunits of luciferase, as well as a 32,000-dalton protein upstream from these genes that could be specifically modified by acyl-coenzyme A and is a component of the bioluminescence system. V. harveyi mRNA that was hybridized to the released from cloned DNA encompassing the luxA and luxB genes was translated in vitro. Luciferase ..cap alpha.. and ..beta.. subunits and the 32,000-dalton polypeptide were detected among the products, along with 42,000- and 55,000-dalton polypeptides, which are encoded downstream from the lux genes and are thought to be involved in luminescence.

  9. Overexpression of Arabidopsis ACBP3 enhances NPR1-dependent plant resistance to Pseudomonas syringe pv tomato DC3000.

    Science.gov (United States)

    Xiao, Shi; Chye, Mee-Len

    2011-08-01

    ACBP3 is one of six Arabidopsis (Arabidopsis thaliana) genes, designated ACBP1 to ACBP6, that encode acyl-coenzyme A (CoA)-binding proteins (ACBPs). These ACBPs bind long-chain acyl-CoA esters and phospholipids and are involved in diverse cellular functions, including acyl-CoA homeostasis, development, and stress tolerance. Recombinant ACBP3 binds polyunsaturated acyl-CoA esters and phospholipids in vitro. Here, we show that ACBP3 plays a role in the plant defense response to the bacterial pathogen Pseudomonas syringae pv tomato DC3000. ACBP3 mRNA was up-regulated upon pathogen infection and treatments using pathogen elicitors and defense-related phytohormones. Transgenic Arabidopsis ACBP3 overexpressors (ACBP3-OEs) showed constitutive expression of pathogenesis-related genes (PR1, PR2, and PR5), cell death, and hydrogen peroxide accumulation in leaves. Consequently, ACBP3-OEs displayed enhanced resistance to the bacterial pathogen P. syringae DC3000. In contrast, the acbp3 T-DNA insertional mutant was more susceptible and exhibited lower PR gene transcript levels upon infection. Using the ACBP3 OE-1 line in combination with nonexpressor of PR genes1 (npr1-5) or coronatine-insensitive1 (coi1-2), we concluded that the enhanced PR gene expression and P. syringae DC3000 resistance in the ACBP3-OEs are dependent on the NPR1-mediated, but not the COI1-mediated, signaling pathway. Given that ACBP3-OEs showed greater susceptibility to infection by the necrotrophic fungus Botrytis cinerea while the acbp3 mutant was less susceptible, we suggest that ACBP3 plays a role in the plant defense response against biotrophic pathogens that is distinct from necrotrophic pathogens. ACBP3 function in plant defense was supported further by bioinformatics data showing up-regulation of many biotic and abiotic stress-related genes in ACBP3 OE-1 in comparison with the wild type.

  10. Molecular mechanism of a new Laminaria japonica polysaccharide on the suppression of macrophage foam cell formation via regulating cellular lipid metabolism and suppressing cellular inflammation.

    Science.gov (United States)

    Zha, Xue-Qiang; Xue, Lei; Zhang, Hai-Lin; Asghar, Muhammad-Naeem; Pan, Li-Hua; Liu, Jian; Luo, Jian-Ping

    2015-10-01

    Laminaria japonica is an important marine vegetable with great health benefits for preventing atherosclerosis. Since the foam cell formation is an important hallmark for the initiation of atherosclerosis, we examined the effect and underlying mechanism of a purified L. japonica polysaccharide (LJP61A) on the suppression of macrophage foam cell formation in this study. The chemical structure was further characterized. Using oxidized low-density lipoprotein (ox-LDL)-induced foam cell model, we found that the cellular lipid accumulation was significantly attenuated by 25 μg/mL LJP61A. Meanwhile, LJP61A caused a remarkable decrease in mRNA expression of peroxisome proliferator-activated receptor γ that was accompanied by the reduction of CD36 and Acyl coenzyme A: cholesterol acyltransferase-1 mRNA levels, and the enhancement of ATP-binding cassette transporters A1 and scavenger receptor B1 mRNA levels. Besides these, the ox-LDL-induced cellular inflammation was also restricted by LJP61A treatment via mammalian target of rapamycin-mediated Toll-like receptor 2/4-Mitogen-activated protein kinases/nuclear factor kappa-B pathways. The structure of LJP61A was characterized as a repeating unit consisting of →3,6)-α-d-Manp-(1→, →4)-α-d-Manp-(1→, →4)-2-O-acetyl-β-d-Glcp-(1→, →4)-β-d-Glcp-(1→, →6)-4-O-SO3 -β-d-Galp-(1→, →6)-β-d-Galp-(1→, →3)-β-d-Galp-(1→, and a terminal residue of α-d-Glcp-(1→. Our findings suggest that LJP61A inhibits the conversion of macrophage into foam cell via regulating cellular lipid metabolism and suppressing cellular inflammation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A dynamic, mechanistic model of metabolism in adipose tissue of lactating dairy cattle.

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    McNamara, J P; Huber, K; Kenéz, A

    2016-07-01

    Research in dairy cattle biology has resulted in a large body of knowledge on nutrition and metabolism in support of milk production and efficiency. This quantitative knowledge has been compiled in several model systems to balance and evaluate rations and predict requirements. There are also systems models for metabolism and reproduction in the cow that can be used to support research programs. Adipose tissue plays a significant role in the success and efficiency of lactation, and recent research has resulted in several data sets on genomic differences and changes in gene transcription of adipose tissue in dairy cattle. To fully use this knowledge, we need to build and expand mechanistic, dynamic models that integrate control of metabolism and production. Therefore, we constructed a second-generation dynamic, mechanistic model of adipose tissue metabolism of dairy cattle. The model describes the biochemical interconversions of glucose, acetate, β-hydroxybutyrate (BHB), glycerol, C16 fatty acids, and triacylglycerols. Data gathered from our own research and published references were used to set equation forms and parameter values. Acetate, glucose, BHB, and fatty acids are taken up from blood. The fatty acids are activated to the acyl coenzyme A moieties. Enzymatically catalyzed reactions are explicitly described with parameters including maximal velocity and substrate sensitivity. The control of enzyme activity is partially carried out by insulin and norepinephrine, portraying control in the cow. Model behavior was adequate, with sensitive responses to changing substrates and hormones. Increased nutrient uptake and increased insulin stimulate triacylglycerol synthesis, whereas a reduction in nutrient availability or increase in norepinephrine increases triacylglycerol hydrolysis and free fatty acid release to blood. This model can form a basis for more sophisticated integration of existing knowledge and future studies on metabolic efficiency of dairy cattle

  12. Computational analysis of a novel mutation in ETFDH gene highlights its long-range effects on the FAD-binding motif

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    Chang Jan-Gowth

    2011-10-01

    Full Text Available Abstract Background Multiple acyl-coenzyme A dehydrogenase deficiency (MADD is an autosomal recessive disease caused by the defects in the mitochondrial electron transfer system and the metabolism of fatty acids. Recently, mutations in electron transfer flavoprotein dehydrogenase (ETFDH gene, encoding electron transfer flavoprotein:ubiquinone oxidoreductase (ETF:QO have been reported to be the major causes of riboflavin-responsive MADD. To date, no studies have been performed to explore the functional impact of these mutations or their mechanism of disrupting enzyme activity. Results High resolution melting (HRM analysis and sequencing of the entire ETFDH gene revealed a novel mutation (p.Phe128Ser and the hotspot mutation (p.Ala84Thr from a patient with MADD. According to the predicted 3D structure of ETF:QO, the two mutations are located within the flavin adenine dinucleotide (FAD binding domain; however, the two residues do not have direct interactions with the FAD ligand. Using molecular dynamics (MD simulations and normal mode analysis (NMA, we found that the p.Ala84Thr and p.Phe128Ser mutations are most likely to alter the protein structure near the FAD binding site as well as disrupt the stability of the FAD binding required for the activation of ETF:QO. Intriguingly, NMA revealed that several reported disease-causing mutations in the ETF:QO protein show highly correlated motions with the FAD-binding site. Conclusions Based on the present findings, we conclude that the changes made to the amino acids in ETF:QO are likely to influence the FAD-binding stability.

  13. Metabolic Regulation as a Consequence of Anaerobic 5-Methylthioadenosine Recycling in Rhodospirillum rubrum

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    Justin A. North

    2016-07-01

    Full Text Available Rhodospirillum rubrum possesses a novel oxygen-independent, aerobic methionine salvage pathway (MSP for recycling methionine from 5-methylthioadenosine (MTA, the MTA-isoprenoid shunt. This organism can also metabolize MTA as a sulfur source under anaerobic conditions, suggesting that the MTA-isoprenoid shunt may also function anaerobically as well. In this study, deep proteomics profiling, directed metabolite analysis, and reverse transcriptase quantitative PCR (RT-qPCR revealed metabolic changes in response to anaerobic growth on MTA versus sulfate as sole sulfur source. The abundance of protein levels associated with methionine transport, cell motility, and chemotaxis increased in the presence of MTA over that in the presence of sulfate. Purine salvage from MTA resulted primarily in hypoxanthine accumulation and a decrease in protein levels involved in GMP-to-AMP conversion to balance purine pools. Acyl coenzyme A (acyl-CoA metabolic protein levels for lipid metabolism were lower in abundance, whereas poly-β-hydroxybutyrate synthesis and storage were increased nearly 10-fold. The known R. rubrum aerobic MSP was also shown to be upregulated, to function anaerobically, and to recycle MTA. This suggested that other organisms with gene homologues for the MTA-isoprenoid shunt may also possess a functioning anaerobic MSP. In support of our previous findings that ribulose-1,5-carboxylase/oxygenase (RubisCO is required for an apparently purely anaerobic MSP, RubisCO transcript and protein levels both increased in abundance by over 10-fold in cells grown anaerobically on MTA over those in cells grown on sulfate, resulting in increased intracellular RubisCO activity. These results reveal for the first time global metabolic responses as a consequence of anaerobic MTA metabolism compared to using sulfate as the sulfur source.

  14. Modulation of the Glycerol Phosphate availability led to concomitant reduction in the citric acid excretion and increase in lipid content and yield in Yarrowia lipolytica.

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    Sagnak, Rana; Cochot, Sandrine; Molina-Jouve, Carole; Nicaud, Jean-Marc; Guillouet, Stéphane E

    2018-01-10

    In order to improve TriAcylGycerol (TAG) lipids accumulation in the yeast Yarrowia lipolytica on glucose, double over-expression of the major acyl-CoA:diacylglycerol acyltransferase encoding gene (ylDGA2) and of the glycerol-phosphate dehydrogenase encoding gene (ylGPD1) was carried out. The genes were over-expressed in a strain impaired for the mobilization of the accumulated lipids, through the deletion of the genes encoding acyl-coenzyme A oxidases (POX1-6 genes) and the deletion of the very efficient lipase attached to the lipid bodies, encoded by ylTGL4. This metabolic engineering strategy had the objective of pulling the C-flow into the TAG synthesis by increasing the availability of glycerol-3-phosphate and its binding to fatty acids for the TAG synthesis. This strain showed a strong improvement in production performances on glucose in terms of lipid content (increase from 18 to 55%), lipid yield (increase from 0,035 to 0.14gg -1 ) and by-product formation (decrease in citric acid yield from 0.68 to 0.4gg -1 ). For developing bioprocess for the production of triacylglycerol from renewable carbon sources as glucose it is of first importance to control the C/N ratio in order to avoid citric acid excretion during lipid accumulation. Our engineered strain showed a delay in the onset of citric acid excretion as suggested by the 15% modulation of the critical C/N ratio. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. First report about the mode of action of combined butafosfan and cyanocobalamin on hepatic metabolism in nonketotic early lactating cows.

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    Kreipe, L; Deniz, A; Bruckmaier, R M; van Dorland, H A

    2011-10-01

    The primary aim was to investigate the effect of combined butafosfan and cyanocobalamin on liver metabolism in early lactating cows through mRNA expression measurements of genes encoding 31 enzymes and transport proteins of major metabolic processes in the liver using 16 multiparous early lactating dairy cows. The treatments included i.v. injection of 10 mL/100 kg of body weight combined butafosfan and cyanocobalamin (TG, n = 8) on 3 d consecutively at 25 ± 3 d in milk or injection with physiological saline solution similarly applied (CG, n = 8). Results include a higher daily milk production for TG cows (41.1 ± 0.9 kg, mean ± SEM) compared with CG cows (39.5 ± 0.7 kg). In plasma, the concentration of inorganic phosphorus was lower in the TG cows (1.25 ± 0.08 mmol/L) after the treatment than in the CG cows (1.33 ± 0.07 mmol/L). The plasma β-hydroxybutyrate concentration was 0.65 ± 0.13 mmol/L for all cows before the treatment, and remained unaffected post treatment. The unique result was that in the liver, the mRNA abundance of acyl-coenzyme A synthetase long-chain family member 1, involved in fatty acid oxidation and biosynthesis, was lower across time points after the treatment for TG compared with CG cows (17.5 ± 0.15 versus 18.1 ± 0.24 cycle threshold, log(2), respectively). In conclusion, certain effects of combined butafosfan and cyanocobalamin were observed on mRNA abundance of a gene in the liver of nonketotic early lactating cows. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Biosynthesis of aliphatic polyketides by type III polyketide synthase and methyltransferase in Bacillus subtilis.

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    Nakano, Chiaki; Ozawa, Hiroki; Akanuma, Genki; Funa, Nobutaka; Horinouchi, Sueharu

    2009-08-01

    Type III polyketide synthases (PKSs) synthesize a variety of aromatic polyketides in plants, fungi, and bacteria. The bacterial genome projects predicted that probable type III PKS genes are distributed in a wide variety of gram-positive and -negative bacteria. The gram-positive model microorganism Bacillus subtilis contained the bcsA-ypbQ operon, which appeared to encode a type III PKS and a methyltransferase, respectively. Here, we report the characterization of bcsA (renamed bpsA, for Bacillus pyrone synthase, on the basis of its function) and ypbQ, which are involved in the biosynthesis of aliphatic polyketides. In vivo analysis demonstrated that BpsA was a type III PKS catalyzing the synthesis of triketide pyrones from long-chain fatty acyl-coenzyme A (CoA) thioesters as starter substrates and malonyl-CoA as an extender substrate, and YpbQ was a methyltransferase acting on the triketide pyrones to yield alkylpyrone methyl ethers. YpbQ thus was named BpsB because of its functional relatedness to BpsA. In vitro analysis with histidine-tagged BpsA revealed that it used broad starter substrates and produced not only triketide pyrones but also tetraketide pyrones and alkylresorcinols. Although the aliphatic polyketides were expected to localize in the membrane and play some role in modulating the rigidity and properties of the membrane, no detectable phenotypic changes were observed for a B. subtilis mutant containing a whole deletion of the bpsA-bpsB operon.

  17. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

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    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-02-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

  18. Genetic examination of initial amino acid oxidation and glutamate catabolism in the hyperthermophilic archaeon Thermococcus kodakarensis.

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    Yokooji, Yuusuke; Sato, Takaaki; Fujiwara, Shinsuke; Imanaka, Tadayuki; Atomi, Haruyuki

    2013-05-01

    Amino acid catabolism in Thermococcales is presumed to proceed via three steps: oxidative deamination of amino acids by glutamate dehydrogenase (GDH) or aminotransferases, oxidative decarboxylation by 2-oxoacid:ferredoxin oxidoreductases (KOR), and hydrolysis of acyl-coenzyme A (CoA) by ADP-forming acyl-CoA synthetases (ACS). Here, we performed a genetic examination of enzymes involved in Glu catabolism in Thermococcus kodakarensis. Examination of amino acid dehydrogenase activities in cell extracts of T. kodakarensis KUW1 (ΔpyrF ΔtrpE) revealed high NADP-dependent GDH activity, along with lower levels of NAD-dependent activity. NADP-dependent activities toward Gln/Ala/Val/Cys and an NAD-dependent threonine dehydrogenase activity were also detected. In KGDH1, a gene disruption strain of T. kodakarensis GDH (Tk-GDH), only threonine dehydrogenase activity was detected, indicating that all other activities were dependent on Tk-GDH. KGDH1 could not grow in a medium in which growth was dependent on amino acid catabolism, implying that Tk-GDH is the only enzyme that can discharge the electrons (to NADP(+)/NAD(+)) released from amino acids in their oxidation to 2-oxoacids. In a medium containing excess pyruvate, KGDH1 displayed normal growth, but higher degrees of amino acid catabolism were observed compared to those for KUW1, suggesting that Tk-GDH functions to suppress amino acid oxidation and plays an anabolic role under this condition. We further constructed disruption strains of 2-oxoglutarate:ferredoxin oxidoreductase and succinyl-CoA synthetase. The two strains displayed growth defects in both media compared to KUW1. Succinate generation was not observed in these strains, indicating that the two enzymes are solely responsible for Glu catabolism among the multiple KOR and ACS enzymes in T. kodakarensis.

  19. Inhibition by propionyl-coenzyme A of N-acetylglutamate synthetase in rat liver mitochondria. A possible explanation for hyperammonemia in propionic and methylmalonic acidemia.

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    Coude, F X; Sweetman, L; Nyhan, W L

    1979-01-01

    In the search for the mechanism by which hyperammonemia complicates propionic and methylmalonic acidemia the effects of a series of acyl-coenzyme A (CoA) derivatives were studied on the activity of N-acetylglutamate synthetase in rat liver mitochondria using acetyl-CoA as substrate. Propionyl-CoA was found to be a competitive inhibitor. The inhibition constant of 0.71 mM is in the range of concentrations of propionate found in the serum of patients with propionic and methylmalonic acidemia. Propionyl-CoA was also found to be a substrate for N-acetylglutamate synthetase, forming N-propionylglutamate. This compound was a weak activator of rat liver carbamoylphosphate synthetase; the activation constant was 1.1 mM as compared with 0.12 mM for N-acetylglutamate. A decreased level of N-acetylglutamate in liver mitochondria that would follow inhibition of N-acetylglutamate synthetase by propionyl-CoA would be expected to lead to hyperammonemia. Methylmalonyl-CoA, tiglyl-CoA, and isovaleryl-CoA at a concentration of 3 mM caused 30-70% inhibition of N-acetylglutamate synthetase. 3the latter two compounds are readily detoxified by the formation of N-acylglycine conjugates in liver, which may prevent large accumulations and could explain why hyperammonemia is not characteristic of patients with beta-ketothiolase deficiency or isovaleric acidemia in whom these compounds would be expected to be elevated. PMID:500823

  20. Targeted enhancement of glutamate-to-γ-aminobutyrate conversion in Arabidopsis seeds affects carbon-nitrogen balance and storage reserves in a development-dependent manner.

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    Fait, Aaron; Nesi, Adriano Nunes; Angelovici, Ruthie; Lehmann, Martin; Pham, Phuong Anh; Song, Luhua; Haslam, Richard P; Napier, Johnathan A; Galili, Gad; Fernie, Alisdair R

    2011-11-01

    In seeds, glutamate decarboxylase (GAD) operates at the metabolic nexus between carbon and nitrogen metabolism by catalyzing the unidirectional decarboxylation of glutamate to form γ-aminobutyric acid (GABA). To elucidate the regulatory role of GAD in seed development, we generated Arabidopsis (Arabidopsis thaliana) transgenic plants expressing a truncated GAD from Petunia hybrida missing the carboxyl-terminal regulatory Ca(2+)-calmodulin-binding domain under the transcriptional regulation of the seed maturation-specific phaseolin promoter. Dry seeds of the transgenic plants accumulated considerable amounts of GABA, and during desiccation the content of several amino acids increased, although not glutamate or proline. Dry transgenic seeds had higher protein content than wild-type seeds but lower amounts of the intermediates of glycolysis, glycerol and malate. The total fatty acid content of the transgenic seeds was 50% lower than in the wild type, while acyl-coenzyme A accumulated in the transgenic seeds. Labeling experiments revealed altered levels of respiration in the transgenic seeds, and fractionation studies indicated reduced incorporation of label in the sugar and lipid fractions extracted from transgenic seeds. Comparative transcript profiling of the dry seeds supported the metabolic data. Cellular processes up-regulated at the transcript level included the tricarboxylic acid cycle, fatty acid elongation, the shikimate pathway, tryptophan metabolism, nitrogen-carbon remobilization, and programmed cell death. Genes involved in the regulation of germination were similarly up-regulated. Taken together, these results indicate that the GAD-mediated conversion of glutamate to GABA during seed development plays an important role in balancing carbon and nitrogen metabolism and in storage reserve accumulation.

  1. Targeted Enhancement of Glutamate-to-γ-Aminobutyrate Conversion in Arabidopsis Seeds Affects Carbon-Nitrogen Balance and Storage Reserves in a Development-Dependent Manner1[W][OA

    Science.gov (United States)

    Fait, Aaron; Nesi, Adriano Nunes; Angelovici, Ruthie; Lehmann, Martin; Pham, Phuong Anh; Song, Luhua; Haslam, Richard P.; Napier, Johnathan A.; Galili, Gad; Fernie, Alisdair R.

    2011-01-01

    In seeds, glutamate decarboxylase (GAD) operates at the metabolic nexus between carbon and nitrogen metabolism by catalyzing the unidirectional decarboxylation of glutamate to form γ-aminobutyric acid (GABA). To elucidate the regulatory role of GAD in seed development, we generated Arabidopsis (Arabidopsis thaliana) transgenic plants expressing a truncated GAD from Petunia hybrida missing the carboxyl-terminal regulatory Ca2+-calmodulin-binding domain under the transcriptional regulation of the seed maturation-specific phaseolin promoter. Dry seeds of the transgenic plants accumulated considerable amounts of GABA, and during desiccation the content of several amino acids increased, although not glutamate or proline. Dry transgenic seeds had higher protein content than wild-type seeds but lower amounts of the intermediates of glycolysis, glycerol and malate. The total fatty acid content of the transgenic seeds was 50% lower than in the wild type, while acyl-coenzyme A accumulated in the transgenic seeds. Labeling experiments revealed altered levels of respiration in the transgenic seeds, and fractionation studies indicated reduced incorporation of label in the sugar and lipid fractions extracted from transgenic seeds. Comparative transcript profiling of the dry seeds supported the metabolic data. Cellular processes up-regulated at the transcript level included the tricarboxylic acid cycle, fatty acid elongation, the shikimate pathway, tryptophan metabolism, nitrogen-carbon remobilization, and programmed cell death. Genes involved in the regulation of germination were similarly up-regulated. Taken together, these results indicate that the GAD-mediated conversion of glutamate to GABA during seed development plays an important role in balancing carbon and nitrogen metabolism and in storage reserve accumulation. PMID:21921115

  2. The mechanisms underlying the hypolipidaemic effects of Grifola frondosa in the liver of rats

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    Yinrun Ding

    2016-08-01

    Full Text Available The present study investigated the hypolipidaemic effects of Grifola frondosa and its regulation mechanism involved in lipid metabolism in liver of rats fed a high-cholesterol diet. The body weights and serum lipid levels of control rats, of hyperlipidaemic rats and of hyperlipidaemic rats treated with oral Grifola frondosa were determined. mRNA expression and concentration of key lipid metabolism enzymes were investigated. Serum cholesterol, triacylglycerol and low-density lipoprotein cholesterol levels were markedly decreased in hyperlipidaemic rats treated with Grifola frondosa compared with untreated hyperlipidaemic rats. mRNA expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR, acyl-coenzyme A: cholesterol acyltransferase (ACAT2, apolipoprotein B (ApoB, fatty acid synthase (FAS and acetyl-CoA carboxylase (ACC1 were significantly down-regulated, while expression of cholesterol 7-alpha-hydroxylase (CYP7A1 was significantly up-regulated in the livers of treated rats compared with untreated hyperlipidaemic rats. The concentrations of these enzymes also paralleled the observed changes in mRNA expression. Two-dimensional polyacrylamide gel electrophoresis (2-DE and Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS were used to identify twenty proteins differentially expressed in livers of rats treated with Grifola frondosa compared with untreated hyperlipidemic rats. Of these twenty proteins, seven proteins were down-regulated and thirteen proteins were up-regulated. These findings indicate that the hypolipidaemic effects of Grifola frondosa reflected its modulation of key enzymes involved in cholesterol and triacylglycerol biosynthesis, absorption and catabolic pathways. Grifola frondosa may exert anti-atherosclerotic effects by inhibiting LDL oxidation through down-regulation and up-regulating proteins expression in the liver of rats. Therefore, Grifola frondosa may produce both hypolipidaemic

  3. Disrupted fat distribution and composition due to medium-chain triglycerides in mice with a β-oxidation defect.

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    Tucci, Sara; Flögel, Ulrich; Sturm, Marga; Borsch, Elena; Spiekerkoetter, Ute

    2011-08-01

    Because of the enhanced recognition of inherited long-chain fatty acid oxidation disorders by worldwide newborn screening programs, an increasing number of asymptomatic patients receive medium-chain triglyceride (MCT) supplements to prevent the development of cardiomyopathy and myopathy. MCT supplementation has been recognized as a safe dietary intervention, but long-term observations into later adulthood are still not available. We investigated the consequences of a prolonged MCT diet on abdominal fat distribution and composition and on liver fat. Mice with very-long-chain acyl-coenzyme A dehydrogenase deficiency (VLCAD(-/-)) were supplemented for 1 y with a diet in which MCTs replaced long-chain triglycerides without increasing the total fat content. The dietary effects on abdominal fat accumulation and composition were analyzed by in vivo (1)H- and (13)C-magnetic resonance spectroscopy (9.4 Tesla). After 1 y of MCT supplementation, VLCAD(-/-) mice accumulated massive visceral fat and had a dramatic increase in the concentration of serum free fatty acids. Furthermore, we observed a profound shift in body triglyceride composition, ie, concentrations of physiologically important polyunsaturated fatty acids dramatically decreased. (1)H-Magnetic resonance spectroscopy analysis and histologic evaluation of the liver also showed pronounced fat accumulation and marked oxidative stress. Although the MCT-supplemented diet has been reported to prevent the development of cardiomyopathy and skeletal myopathy in fatty acid oxidation disorders, our data show that long-term MCT supplementation results in a severe clinical phenotype similar to that of nonalcoholic steatohepatitis and the metabolic syndrome.

  4. Orphan drugs in development for long-chain fatty acid oxidation disorders: challenges and progress

    Directory of Open Access Journals (Sweden)

    Sun A

    2015-04-01

    Full Text Available Angela Sun, J Lawrence Merritt II Department of Pediatrics, University of Washington, Seattle, WA, USA Abstract: Fatty acid oxidation disorders are inborn errors of metabolism resulting in failure of ß-oxidation within or transport of fatty acids into the mitochondria. The long-chain fatty acid oxidation disorders are characterized by variable presentations ranging from newborn cardiomyopathy, to infantile hypoketotic hypoglycemia resulting from liver involvement, to skeletal myopathy often resulting in rhabdomyolysis in adolescents and adults. Treatments for these long-chain fatty acid oxidation disorders have typically focused upon avoidance of fasting with dietary fat restriction and medium-chain triglyceride supplementation. These treatments have resulted in only a partial response with improvements in hypoglycemia, reduction in frequency of rhabdomyolysis, and improvement in cardiomyopathy with early therapy, but significant risk remains. Recent advances in therapies for long-chain fatty acid oxidation disorders are reviewed in this article. These include sodium D,L-3-hydroxybutyrate, triheptanoin, gene therapy, and bezafibrates. Sodium D,L-3-hydroxybutyrate has shown clinical effect, with improvements in muscle tone, neurological abnormalities, and some cases of cardiomyopathy and leukodystrophy. Triheptanoin has been used as an alternative medium-chain triglyceride in a number of fatty acid oxidation disorders and has shown promising findings in the treatment of cardiomyopathy and hypoglycemia. However, it does not significantly reduce episodes of rhabdomyolysis. Gene therapy has been shown to improve acylcarnitine levels in very-long-chain acyl-coenzyme A dehydrogenase deficiency mouse models, with preservation of glucose levels. Bezafibrates have shown improvements in acylcarnitine concentrations in fibroblast studies, but clinical observations have not demonstrated consistent effects. Together, these treatments have shown some

  5. Analysis of lipid profile in lipid storage myopathy.

    Science.gov (United States)

    Aguennouz, M'hammed; Beccaria, Marco; Purcaro, Giorgia; Oteri, Marianna; Micalizzi, Giuseppe; Musumesci, Olimpia; Ciranni, Annmaria; Di Giorgio, Rosa Maria; Toscano, Antonio; Dugo, Paola; Mondello, Luigi

    2016-09-01

    Lipid dysmetabolism disease is a condition in which lipids are stored abnormally in organs and tissues throughout the body, causing muscle weakness (myopathy). Usually, the diagnosis of this disease and its characterization goes through dosage of Acyl CoA in plasma accompanied with evidence of droplets of intra-fibrils lipids in the patient muscle biopsy. However, to understand the pathophysiological mechanisms of lipid storage diseases, it is useful to identify the nature of lipids deposited in muscle fiber. In this work fatty acids and triglycerides profile of lipid accumulated in the muscle of people suffering from myopathies syndromes was characterized. In particular, the analyses were carried out on the muscle biopsy of people afflicted by lipid storage myopathy, such as multiple acyl-coenzyme A dehydrogenase deficiency, and neutral lipid storage disease with myopathy, and by the intramitochondrial lipid storage dysfunctions, such as deficiencies of carnitine palmitoyltransferase II enzyme. A single step extraction and derivatization procedure was applied to analyze fatty acids from muscle tissues by gas chromatography with a flame ionization detector and with an electronic impact mass spectrometer. Triglycerides, extracted by using n-hexane, were analyzed by high performance liquid chromatography coupled to mass spectrometer equipped with an atmospheric pressure chemical ionization interface. The most representative fatty acids in all samples were: C16:0 in the 13-24% range, C18:1n9 in the 20-52% range, and C18:2n6 in the 10-25% range. These fatty acids were part of the most representative triglycerides in all samples. The data obtained was statistically elaborated performing a principal component analysis. A satisfactory discrimination was obtained among the different diseases. Using component 1 vs component 3 a 43.3% of total variance was explained. Such results suggest the important role that lipid profile characterization can have in supporting a correct

  6. Effects of dietary supplementation of coriander oil, in canola oil diets, on the metabolism of [1-(14)C] 18:3n-3 and [1-(14)C] 18:2n-6 in rainbow trout hepatocytes.

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    Randall, K M; Drew, M D; Øverland, M; Østbye, T-K; Bjerke, M; Vogt, G; Ruyter, B

    2013-09-01

    The aim of this study was to investigate the effects of petroselinic acid, found in coriander oil, on the ability of rainbow trout hepatocytes to increase the production of eicosapentaenoic acid (20:5n-3; EPA) and docosahexaenoic acid (22:6n-3; DHA) from [1-(14)C] α-linolenic acid (18:3n-3; ALA) and to reduce the production of arachidonic acid (20:4n-6; ARA) from [1-(14)C] 18:2n-6. Addition of coriander oil increased the production of 22:6n-3, from [1-(14)C] 18:3n-3, at the 0.5 and 1.0% inclusion levels and reduced the conversion of [1-(14)C] 18:2n-6 to 20:4n-6. β-Oxidation was significantly increased at the 1.5% inclusion level for [1-(14)C] 18:2n-6, however β-oxidation for [1-(14)C] 18:3n-3 only showed an increasing trend. Acetate, a main breakdown product of fatty acids (FA) via peroxisomal β-oxidation, decreased three-fold for [1-(14)C] 18:2n-6 and nearly doubled for [1-(14)C] 18:3n-3 when coriander was added at a 1.5% inclusion level. Acyl coenzyme A oxidase (ACO) enzyme activity showed no significant differences between treatments. Relative gene expression of ∆6 desaturase decreased with addition of coriander oil compared to the control. The addition of petroselinic acid via coriander oil to vegetable oil (VO) based diets containing no fishmeal (FM) or fish oil (FO), significantly increased the production of anti-inflammatory precursor 22:6n-3 (P=0.011) and decreased pro-inflammatory precursor 20:4n-6 (P=0.023) in radiolabelled hepatocytes of rainbow trout. © 2013.

  7. Cloning and genetic characterization of dca genes required for beta-oxidation of straight-chain dicarboxylic acids in Acinetobacter sp. strain ADP1.

    Science.gov (United States)

    Parke, D; Garcia, M A; Ornston, L N

    2001-10-01

    A previous study of deletions in the protocatechuate (pca) region of the Acinetobacter sp. strain ADP1 chromosome revealed that genes required for utilization of the six-carbon dicarboxylic acid, adipic acid, are linked to the pca structural genes. To investigate the genes involved in adipate catabolism, a 33.8-kb SacI fragment, which corrects a deletion spanning this region, was cloned. In addition to containing known pca, qui, and pob genes (for protocatechuate, quinate, and 4-hydroxybenzoate dissimilation), clone pZR8000 contained 10 kb of DNA which was the subject of this investigation. A mutant strain of Escherichia coli DH5alpha, strain EDP1, was isolated that was able to utilize protocatechuate and 4-hydroxybenzoate as growth substrates when EDP1 cells contained pZR8000. Sequence analysis of the new region of DNA on pZR8000 revealed open reading frames predicted to be involved in beta-oxidation. Knockouts of three genes implicated in beta-oxidation steps were introduced into the chromosome of Acinetobacter sp. strain ADP1. Each of the mutants was unable to grow with adipate. Because the mutants were affected in their ability to utilize additional saturated, straight-chain dicarboxylic acids, the newly discovered 10 kb of DNA was termed the dca (dicarboxylic acid) region. Mutant strains included one with a deletion in dcaA (encoding an acyl coenzyme A [acyl-CoA] dehydrogenase homolog), one with a deletion in dcaE (encoding an enoyl-CoA hydratase homolog), and one with a deletion in dcaH (encoding a hydroxyacyl-CoA dehydrogenase homolog). Data on the dca region should help us probe the functional significance and interrelationships of clustered genetic elements in this section of the Acinetobacter chromosome.

  8. Post-mortem analysis for two prevalent beta-oxidation mutations in sudden infant death.

    Science.gov (United States)

    Yang, Zi; Lantz, Patrick E; Ibdah, Jamal A

    2007-12-01

    Fatty acid oxidation disorders may cause sudden and unexpected infant death and are associated with the histological hallmark of hepatic steatosis. The goal of the present study was to assess the value of post-mortem molecular analysis for medium-chain acyl-coenzyme A dehydrogenase (MCAD) and mitochondrial trifunctional protein (MTP) defects in unexplained sudden infant death (SID) associated with fatty infiltration of the liver. MCAD catalyzes the first step of medium-chain fatty acid oxidation while MTP catalyzes the last three steps of long-chain fatty acid oxidation. In a retrospective study, 220 consecutive cases of sudden and unexplained infant death certified by medical examiners at Wake Forest University Medical Center were assessed for hepatic steatosis. Subjects with evidence of hepatic steatosis were screened for mutations in MCAD and MTPalpha-subunit using DNA isolated from paraffin-embedded liver tissue, single-strand conformation variance, and nucleotide sequence analyses. Sixteen cases (7.3%) were associated with diffuse micro-vesicular or mixed micro- and macro-vesicular hepatic steatosis. Two of these 16 cases (12.5%) had disease-causing mutations. One was homozygous for the prevalent MCAD A985G mutation. The second was a compound heterozygous for the prevalent MTP G1528C mutation and a novel 1 bp deletion in exon 18 of the MTPalpha-subunit gene. A significant proportion (7.3%) of SID is associated with hepatic steatosis. The present data support post-mortem molecular analysis for the MCAD A985G and MTP G1528C prevalent mutations in cases of sudden and unexplained infant death associated with hepatic steatosis.

  9. Sex differences in global mRNA content of human skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Amy C Maher

    Full Text Available Women oxidize more fat as compared to men during endurance exercise and several groups have shown that the mRNA content of selected genes related to fat oxidation are higher in women (e.g. hormone sensitive lipase, beta-hydroxyacyl-CoA dehydrogenase, CD36. One of the possible mechanisms is that women tend to have a higher area percentage of type I skeletal muscle fibers as compared with men. Consequently, we hypothesized that sex would influence the basal mRNA and protein content for genes involved in metabolism and the determination of muscle fiber type. Muscle biopsies from the vastus lateralis were collected from healthy men and women. We examined mRNA content globally using Affymetrix GeneChips, and selected genes were examined and/or confirmed by RT-PCR. Furthermore, we examined protein content by Western blot analysis. Stringent gene array analysis revealed 66 differentially expressed genes representing metabolism, mitochondrial function, transport, protein biosynthesis, cell proliferation, signal transduction pathways, transcription and translation. Stringent gene array analysis and RT-PCR confirmed that mRNA for; acyl-coenzyme A acyltransferase 2 (ACAA2, trifunctional protein beta (HADHB, catalase, lipoprotein lipase (LPL, and uncoupling protein-2 (UCP-2 were higher in women. Targeted gene analysis revealed that myosin heavy chain I (MHCI, peroxisome proliferator-activated receptor (PPARdelta were higher in women compared with men. Surprisingly, there were no significant sex based differences in protein content for HADHB, ACAA2, catalase, PPARdelta, and MHC1. In conclusion, the differences in the basal mRNA content in resting skeletal muscle suggest that men and women are transcriptionally "primed" for known physiological differences in metabolism however the mechanism behind sex differences in fiber type remains to be determined.

  10. Evidence for Intramyocardial Disruption of Lipid Metabolism and Increased Myocardial Ketone Utilization in Advanced Human Heart Failure.

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    Bedi, Kenneth C; Snyder, Nathaniel W; Brandimarto, Jeffrey; Aziz, Moez; Mesaros, Clementina; Worth, Andrew J; Wang, Linda L; Javaheri, Ali; Blair, Ian A; Margulies, Kenneth B; Rame, J Eduardo

    2016-02-23

    The failing human heart is characterized by metabolic abnormalities, but these defects remains incompletely understood. In animal models of heart failure there is a switch from a predominance of fatty acid utilization to the more oxygen-sparing carbohydrate metabolism. Recent studies have reported decreases in myocardial lipid content, but the inclusion of diabetic and nondiabetic patients obscures the distinction of adaptations to metabolic derangements from adaptations to heart failure per se. We performed both unbiased and targeted myocardial lipid surveys using liquid chromatography-mass spectroscopy in nondiabetic, lean, predominantly nonischemic, advanced heart failure patients at the time of heart transplantation or left ventricular assist device implantation. We identified significantly decreased concentrations of the majority of myocardial lipid intermediates, including long-chain acylcarnitines, the primary subset of energetic lipid substrate for mitochondrial fatty acid oxidation. We report for the first time significantly reduced levels of intermediate and anaplerotic acyl-coenzyme A (CoA) species incorporated into the Krebs cycle, whereas the myocardial concentration of acetyl-CoA was significantly increased in end-stage heart failure. In contrast, we observed an increased abundance of ketogenic β-hydroxybutyryl-CoA, in association with increased myocardial utilization of β-hydroxybutyrate. We observed a significant increase in the expression of the gene encoding succinyl-CoA:3-oxoacid-CoA transferase, the rate-limiting enzyme for myocardial oxidation of β-hydroxybutyrate and acetoacetate. These findings indicate increased ketone utilization in the severely failing human heart independent of diabetes mellitus, and they support the role of ketone bodies as an alternative fuel and myocardial ketone oxidation as a key metabolic adaptation in the failing human heart. © 2016 American Heart Association, Inc.

  11. Burkholderia cenocepacia ShvR-regulated genes that influence colony morphology, biofilm formation, and virulence.

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    Subramoni, Sujatha; Nguyen, David T; Sokol, Pamela A

    2011-08-01

    Burkholderia cenocepacia is an opportunistic pathogen that primarily infects cystic fibrosis (CF) patients. Previously, we reported that ShvR, a LysR regulator, influences colony morphology, virulence, and biofilm formation and regulates the expression of an adjacent 24-kb genomic region encoding 24 genes. In this study, we report the functional characterization of selected genes in this region. A Tn5 mutant with shiny colony morphology was identified with a polar mutation in BCAS0208, predicted to encode an acyl-coenzyme A dehydrogenase. Mutagenesis of BCAS0208 and complementation analyses revealed that BCAS0208 is required for rough colony morphology, biofilm formation, and virulence on alfalfa seedlings. It was not possible to complement with BCAS0208 containing a mutation in the catalytic site. BCAS0201, encoding a putative flavin adenine dinucleotide (FAD)-dependent oxidoreductase, and BCAS0207, encoding a putative citrate synthase, do not influence colony morphology but are required for optimum levels of biofilm formation and virulence. Both BCAS0208 and BCAS0201 contribute to pellicle formation, although individual mutations in each of these genes had no appreciable effect on pellicle formation. A mutant with a polar insertion in BCAS0208 was significantly less virulent in a rat model of chronic lung infection as well as in the alfalfa model. Genes in this region were shown to influence utilization of branched-chain fatty acids, tricarboxylic acid cycle substrates, l-arabinose, and branched-chain amino acids. Together, our data show that the ShvR-regulated genes BCAS0208 to BCAS0201 are required for the rough colony morphotype, biofilm and pellicle formation, and virulence in B. cenocepacia.

  12. Serum starvation of ARPE-19 changes the cellular distribution of cholesterol and Fibulin3 in patterns reminiscent of age-related macular degeneration.

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    Rajapakse, Dinusha; Peterson, Katherine; Mishra, Sanghamitra; Wistow, Graeme

    2017-12-15

    Retinal pigment epithelium (RPE) has been implicated as key source of cholesterol-rich deposits at Bruch's membrane (BrM) and in drusen in aging human eye. We have shown that serum-deprivation of confluent RPE cells is associated with upregulation of cholesterol synthesis and accumulation of unesterified cholesterol (UC). Here we investigate the cellular processes involved in this response. We compared the distribution and localization of UC and esterified cholesterol (EC); the age-related macular degeneration (AMD) associated EFEMP1/Fibulin3 (Fib3); and levels of acyl-coenzyme A (CoA): cholesterol acyltransferases (ACAT) ACAT1, ACAT2 and Apolipoprotein B (ApoB) in ARPE-19 cells cultured in serum-supplemented and serum-free media. The results were compared with distributions of these lipids and proteins in human donor eyes with AMD. Serum deprivation of ARPE-19 was associated with increased formation of FM dye-positive membrane vesicles, many of which co-labeled for UC. Additionally, UC colocalized with Fib3 in distinct granules. By day 5, serum-deprived cells grown on transwells secreted Fib3 basally into the matrix. While mRNA and protein levels of ACTA1 were constant over several days of serum-deprivation, ACAT2 levels increased significantly after serum-deprivation, suggesting increased formation of EC. The lower levels of intracellular EC observed under serum-deprivation were associated with increased formation and secretion of ApoB. The responses to serum-deprivation in RPE-derived cells: accumulation and secretion of lipids, lipoproteins, and Fib3 are very similar to patterns seen in human donor eyes with AMD and suggest that this model mimics processes relevant to disease progression. Published by Elsevier Inc.

  13. Decreased liver triglyceride content in adult rats exposed to protein restriction during gestation and lactation: role of hepatic triglyceride utilization.

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    Qasem, Rani J; Li, Jing; Tang, Hee Man; Browne, Veron; Mendez-Garcia, Claudia; Yablonski, Elizabeth; Pontiggia, Laura; D'Mello, Anil P

    2015-04-01

    We have previously demonstrated that protein restriction throughout gestation and lactation reduces liver triglyceride content in adult rat offspring. However, the mechanisms mediating the decrease in liver triglyceride content are not understood. The aim of the current study was to use a new group of pregnant animals and their offspring and determine the contribution of increased triglyceride utilization via the hepatic fatty-acid oxidation and triglyceride secretory pathways to the reduction in liver triglyceride content. Pregnant Sprague-Dawley rats received either a control or a low protein diet throughout pregnancy and lactation. Pups were weaned onto laboratory chow on day 28 and killed on day 65. Liver triglyceride content was reduced in male, but not female, low-protein offspring, both in the fed and fasted states. The reduction was accompanied by a trend towards higher liver carnitine palmitoyltransferase-1a activity, suggesting increased fatty-acid transport into the mitochondrial matrix. However, medium-chain acyl coenzyme A dehydrogenase activity within the mitochondrial matrix, expression of nuclear peroxisome proliferator activated receptor-α, and plasma levels of β-hydroxybutyrate were similar between low protein and control offspring, indicating a lack of change in fatty-acid oxidation. Hepatic triglyceride secretion, assessed by blocking peripheral triglyceride utilization and measuring serum triglyceride accumulation rate, and the activity of microsomal transfer protein, were similar between low protein and control offspring. Because enhanced triglyceride utilization is not a significant contributor, the decrease in liver triglyceride content in male low-protein offspring is likely due to alterations in liver fatty-acid transport or triglyceride biosynthesis. © 2015 Wiley Publishing Asia Pty Ltd.

  14. Therapeutic potential of chalcones as cardiovascular agents.

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    Mahapatra, Debarshi Kar; Bharti, Sanjay Kumar

    2016-03-01

    Cardiovascular diseases are the leading cause of death affecting 17.3 million people across the globe and are estimated to affect 23.3 million people by year 2030. In recent years, about 7.3 million people died due to coronary heart disease, 9.4 million deaths due to high blood pressure and 6.2 million due to stroke, where obesity and atherosclerotic progression remain the chief pathological factors. The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates to inhibit various cardiovascular, hematological and anti-obesity targets like angiotensin converting enzyme (ACE), cholesteryl ester transfer protein (CETP), diacylglycerol acyltransferase (DGAT), acyl-coenzyme A: cholesterol acyltransferase (ACAT), pancreatic lipase (PL), lipoprotein lipase (LPL), calcium (Ca(2+))/potassium (K(+)) channel, COX-1, TXA2 and TXB2. In this review, a comprehensive study of chalcones, their therapeutic targets, structure activity relationships (SARs), mechanisms of actions (MOAs) have been discussed. Chemically diverse chalcone scaffolds, their derivatives including structural manipulation of both aryl rings, replacement with heteroaryl scaffold(s) and hybridization through conjugation with other pharmacologically active scaffold have been highlighted. Chalcones which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-hypertensive, anti-anginal, anti-arrhythmic and cardioprotective agents. With the knowledge of these molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective chalcone derivatives as potential cardiovascular agents. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. The acyl-CoA binding protein affects Monascus pigment production in Monascus ruber CICC41233.

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    Long, Chuannan; Liu, Mengmeng; Chen, Xia; Wang, Xiaofang; Ai, Mingqiang; Cui, Jingjing; Zeng, Bin

    2018-02-01

    The present study verified whether acyl-coenzyme A (acyl-CoA)-binding protein (ACBP) affected the production of Monascus pigments (MPs) in Monascus ruber CICC41233 (MrACBP). Phylogenetic analysis revealed that the cloned Mracbp gene, which encoded the MrACBP protein, exhibited the closest match (99% confidence level) to the gene from Penicilliopsis zonata . The MrACBP and maltose-binding protein (MBP) were simultaneously expressed in Escherichia coli Rosetta DE3 in the form of a fusion protein. The microscale thermophoresis binding assay revealed that the purified MBP-MrACBP exhibited a higher affinity for myristoyl-CoA (Kd = 88.16 nM) than for palmitoyl-CoA (Kd = 136.07 nM) and octanoyl-CoA (Kd = 270.9 nM). Further, the Mracbp gene was homologously overexpressed in M. ruber CICC41233, and a positive transformant M. ruber ACBP5 was isolated. The fatty acid myristic acid in M. ruber ACBP5 was lower than that in the parent strain M. ruber CICC41233. However, when compared with the parent strain, the production of total MPs, water-soluble pigment, and ethanol-soluble pigment in M. ruber ACBP5 increased by 11.67, 9.80, and 12.70%, respectively, after 6 days. The relative gene expression level, as determined by a quantitative real-time polymerase chain reaction analysis, of the key genes acbp , pks , mppr1 , fasA , and fasB increased by 4.03-, 3.58-, 1.67-, 2.11-, and 2.62-fold after 6 days. These data demonstrate the binding preference of MrACBP for myristoyl-CoA, and its influence on MPs production.

  16. Structural and mechanistic studies on carboxymethylproline synthase (CarB), a unique member of the crotonase superfamily catalyzing the first step in carbapenem biosynthesis.

    Science.gov (United States)

    Sleeman, Mark C; Sorensen, John L; Batchelar, Edward T; McDonough, Michael A; Schofield, Christopher J

    2005-10-14

    The first step in the biosynthesis of the medicinally important carbapenem family of beta-lactam antibiotics is catalyzed by carboxymethylproline synthase (CarB), a unique member of the crotonase superfamily. CarB catalyzes formation of (2S,5S)-carboxymethylproline [(2S,5S)-t-CMP] from malonyl-CoA and l-glutamate semialdehyde. In addition to using a cosubstrate, CarB catalyzes C-C and C-N bond formation processes as well as an acyl-coenzyme A hydrolysis reaction. We describe the crystal structure of CarB in the presence and absence of acetyl-CoA at 2.24 A and 3.15 A resolution, respectively. The structures reveal that CarB contains a conserved oxy-anion hole probably required for decarboxylation of malonyl-CoA and stabilization of the resultant enolate. Comparison of the structures reveals that conformational changes (involving His(229)) in the cavity predicted to bind l-glutamate semialdehyde occur on (co)substrate binding. Mechanisms for the formation of the carboxymethylproline ring are discussed in the light of the structures and the accompanying studies using isotopically labeled substrates; cyclization via 1,4-addition is consistent with the observed labeling results (providing that hydrogen exchange at the C-6 position of carboxymethylproline does not occur). The side chain of Glu(131) appears to be positioned to be involved in hydrolysis of the carboxymethylproline-CoA ester intermediate. Labeling experiments ruled out the possibility that hydrolysis proceeds via an anhydride in which water attacks a carbonyl derived from Glu(131), as proposed for 3-hydroxyisobutyryl-CoA hydrolase. The structural work will aid in mutagenesis studies directed at altering the selectivity of CarB to provide intermediates for the production of clinically useful carbapenems.

  17. Early energy metabolism-related molecular events in skeletal muscle of diabetic rats: The effects of l-arginine and SOD mimic.

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    Stancic, Ana; Filipovic, Milos; Ivanovic-Burmazovic, Ivana; Masovic, Sava; Jankovic, Aleksandra; Otasevic, Vesna; Korac, Aleksandra; Buzadzic, Biljana; Korac, Bato

    2017-06-25

    Considering the vital role of skeletal muscle in control of whole-body metabolism and the severity of long-term diabetic complications, we aimed to reveal the molecular pattern of early diabetes-related skeletal muscle phenotype in terms of energy metabolism, focusing on regulatory mechanisms, and the possibility to improve it using two redox modulators, l-arginine and superoxide dismutase (SOD) mimic. Alloxan-induced diabetic rats (120 mg/kg) were treated with l-arginine or the highly specific SOD mimic, M40403, for 7 days. As appropriate controls, non-diabetic rats received the same treatments. We found that l-arginine and M40403 restored diabetes-induced impairment of phospho-5'-AMP-activated protein kinase α (AMPKα) signaling by upregulating AMPKα protein itself and its downstream effectors, peroxisome proliferator-activated receptor-γ coactivator-1α and nuclear respiratory factor 1. Also, there was a restitution of the protein levels of oxidative phosphorylation components (complex I, complex II and complex IV) and mitofusin 2. Furthermore, l-arginine and M40403 induced translocation of glucose transporter 4 to the membrane and upregulation of protein of phosphofructokinase and acyl coenzyme A dehydrogenase, diminishing negative diabetic effects on limiting factors of glucose and lipid metabolism. Both treatments abolished diabetes-induced downregulation of sarcoplasmic reticulum calcium-ATPase proteins (SERCA 1 and 2). Similar effects of l-arginine and SOD mimic treatments suggest that disturbances in the superoxide/nitric oxide ratio may be responsible for skeletal muscle mitochondrial and metabolic impairment in early diabetes. Our results provide evidence that l-arginine and SOD mimics have potential in preventing and treating metabolic disturbances accompanying this widespread metabolic disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Production and release of acylcarnitines by primary myotubes reflect the differences in fasting fat oxidation of the donors.

    Science.gov (United States)

    Wolf, Magnus; Chen, Shili; Zhao, Xinjie; Scheler, Mika; Irmler, Martin; Staiger, Harald; Beckers, Johannes; de Angelis, Martin Hrabé; Fritsche, Andreas; Häring, Hans-Ulrich; Schleicher, Erwin D; Xu, Guowang; Lehmann, Rainer; Weigert, Cora

    2013-06-01

    Acylcarnitines are biomarkers of incomplete β-oxidation and mitochondrial lipid overload but indicate also high rates of mitochondrial fatty acid oxidation. It is unknown whether the production of acylcarnitines in primary human myotubes obtained from lean, metabolically healthy subjects reflects the fat oxidation in vivo. Our objective was to quantify the acylcarnitine production in myotubes obtained from subjects with low and high fasting respiratory quotient (RQ). Fasting RQ was determined by indirect calorimetry. Muscle biopsies from the vastus lateralis muscle were taken from 6 subjects with low fasting RQ (mean 0.79 ± 0.03) and 6 with high fasting RQ (0.90 ± 0.03), and satellite cells were isolated, cultured, and differentiated to myotubes. Myotubes were cultivated with 125 μM (13)C-labeled palmitate for 30 minutes and 4 and 24 hours. Quantitative profiling of 42 intracellular and 31 extracellular acylcarnitines was performed by stable isotope dilution-based metabolomics analysis by liquid chromatography coupled to mass spectrometry. Myotubes from donors with high fasting RQ produced and released significant higher amounts of medium-chain acylcarnitines. High (13)C8 and (13)C10 acylcarnitine levels in the extracellular compartment correlated with high fasting RQ. The decreased expression of medium-chain acyl-coenzyme A dehydrogenase (MCAD) in these myotubes can explain the higher rate of incomplete fatty acid oxidation. A lower intracellular [(13)C]acetylcarnitine to carnitine and lower intracellular (13)C16/(13)C18 acylcarnitine to carnitine ratio indicate reduced fatty acid oxidation capacity in these myotubes. Mitochondrial DNA content was not different. Acylcarnitine production and release from primary human myotubes of donors with high fasting RQ indicate a reduced fatty acid oxidation capacity and a higher rate of incomplete fatty acid oxidation. Thus, quantitative profiling of acylcarnitine production in human myotubes can be a suitable tool to

  19. PPARα Protein Expression Was Increased by Four Weeks of Intermittent Hypoxic Training via AMPKα2-Dependent Manner in Mouse Skeletal Muscle.

    Directory of Open Access Journals (Sweden)

    Ge Li

    Full Text Available Peroxisome proliferator-activated receptor α (PPARα is critical for muscle endurance due to its role in the regulation of fatty acid oxidation. The 5'-AMP-activated protein kinase (AMPK is an energy sensor in cells, but its role in PPARα regulation in vivo remains unknown. In this study, we examined PPARα expression in the skeletal muscle of AMPKα2 overexpression (OE, knockout (KO and wild-type (WT mice after four weeks of exercise under intermittent hypoxia. WT, OE and KO mice were used at 40 mice/strain and randomly subdivided into four subgroups: control (C, running (R, hypoxia (H, and running plus hypoxia (R+H at 10 mice/group. The treadmill running was performed at the speed of 12 m/min, 60 min/day with a slope of 0 degree for four weeks. The hypoxia treatment was performed in daytime with normobaric hypoxia (11.20% oxygen, 8 hours/day. In the R+H group, the treadmill running was conducted in the hypoxic condition. AMPKα2, phosphor-AMPKα (p-AMPKα (Thr172, nuclear PPARα proteins were measured by Western blot and the medium chain acyl coenzyme A dehydrogenase (MCAD mRNA, the key enzyme for fatty acid oxidation and one of the PPARα target genes, was also measured in skeletal muscles after the interventions. The results showed that nuclear PPARα protein was significantly increased by R+H in WT muscles, the increase was enhanced by 41% (p<0.01 in OE mice, but was reduced by 33% (p<0.01 in KO mice. The MCAD mRNA expression was increased after four weeks of R+H intervention. The change in MCAD mRNA followed a similar trend as that of PPARα protein in OE and KO mice. Our data suggest that the increase in nuclear PPARα protein by four-week exercise training under the intermittent hypoxia was dependent on AMPK activation.

  20. PPARα Protein Expression Was Increased by Four Weeks of Intermittent Hypoxic Training via AMPKα2-Dependent Manner in Mouse Skeletal Muscle.

    Science.gov (United States)

    Li, Ge; Wang, Jianxiong; Ye, Jianping; Zhang, Yimin; Zhang, Ying

    2015-01-01

    Peroxisome proliferator-activated receptor α (PPARα) is critical for muscle endurance due to its role in the regulation of fatty acid oxidation. The 5'-AMP-activated protein kinase (AMPK) is an energy sensor in cells, but its role in PPARα regulation in vivo remains unknown. In this study, we examined PPARα expression in the skeletal muscle of AMPKα2 overexpression (OE), knockout (KO) and wild-type (WT) mice after four weeks of exercise under intermittent hypoxia. WT, OE and KO mice were used at 40 mice/strain and randomly subdivided into four subgroups: control (C), running (R), hypoxia (H), and running plus hypoxia (R+H) at 10 mice/group. The treadmill running was performed at the speed of 12 m/min, 60 min/day with a slope of 0 degree for four weeks. The hypoxia treatment was performed in daytime with normobaric hypoxia (11.20% oxygen, 8 hours/day). In the R+H group, the treadmill running was conducted in the hypoxic condition. AMPKα2, phosphor-AMPKα (p-AMPKα) (Thr172), nuclear PPARα proteins were measured by Western blot and the medium chain acyl coenzyme A dehydrogenase (MCAD) mRNA, the key enzyme for fatty acid oxidation and one of the PPARα target genes, was also measured in skeletal muscles after the interventions. The results showed that nuclear PPARα protein was significantly increased by R+H in WT muscles, the increase was enhanced by 41% (p<0.01) in OE mice, but was reduced by 33% (p<0.01) in KO mice. The MCAD mRNA expression was increased after four weeks of R+H intervention. The change in MCAD mRNA followed a similar trend as that of PPARα protein in OE and KO mice. Our data suggest that the increase in nuclear PPARα protein by four-week exercise training under the intermittent hypoxia was dependent on AMPK activation.

  1. Characterization of the Xylella fastidiosa PD1311 gene mutant and its suppression of Pierce's disease on grapevines.

    Science.gov (United States)

    Hao, Lingyun; Johnson, Kameka; Cursino, Luciana; Mowery, Patricia; Burr, Thomas J

    2017-06-01

    Xylella fastidiosa causes Pierce's disease (PD) on grapevines, leading to significant economic losses in grape and wine production. To further our understanding of X. fastidiosa virulence on grapevines, we examined the PD1311 gene, which encodes a putative acyl-coenzyme A (acyl-CoA) synthetase, and is highly conserved across Xylella species. It was determined that PD1311 is required for virulence, as the deletion mutant, ΔPD1311, was unable to cause disease on grapevines. The ΔPD1311 strain was impaired in behaviours known to be associated with PD development, including motility, aggregation and biofilm formation. ΔPD1311 also expressed enhanced sensitivity to H 2 O 2 and polymyxin B, and showed reduced survival in grapevine sap, when compared with wild-type X. fastidiosa Temecula 1 (TM1). Following inoculation, ΔPD1311 could not be detected in grape shoots, which may be related to its altered growth and sensitivity phenotypes. Inoculation with ΔPD1311 2 weeks prior to TM1 prevented the development of PD in a significant fraction of vines and eliminated detectable levels of TM1. In contrast, vines inoculated simultaneously with TM1 and ΔPD1311 developed disease at the same level as TM1 alone. In these vines, TM1 populations were distributed similarly to populations in TM1-only inoculated plants. These findings suggest that, through an indirect mechanism, pretreatment of vines with ΔPD1311 suppresses pathogen population and disease. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  2. High ACSL5 transcript levels associate with systemic lupus erythematosus and apoptosis in Jurkat T lymphocytes and peripheral blood cells.

    Directory of Open Access Journals (Sweden)

    Antonio Catalá-Rabasa

    Full Text Available BACKGROUND: Systemic lupus erythematosus (SLE is a prototypical autoimmune disease in which increased apoptosis and decreased apoptotic cells removal has been described as most relevant in the pathogenesis. Long-chain acyl-coenzyme A synthetases (ACSLs have been involved in the immunological dysfunction of mouse models of lupus-like autoimmunity and apoptosis in different in vitro cell systems. The aim of this work was to assess among the ACSL isoforms the involvement of ACSL2, ACSL4 and ACSL5 in SLE pathogenesis. FINDINGS: With this end, we determined the ACSL2, ACSL4 and ACSL5 transcript levels in peripheral blood mononuclear cells (PBMCs of 45 SLE patients and 49 healthy controls by quantitative real time-PCR (q-PCR. We found that patients with SLE had higher ACSL5 transcript levels than healthy controls [median (range, healthy controls = 16.5 (12.3-18.0 vs. SLE = 26.5 (17.8-41.7, P = 3.9×10 E-5] but no differences were found for ACSL2 and ACSL4. In in vitro experiments, ACSL5 mRNA expression was greatly increased when inducing apoptosis in Jurkat T cells and PBMCs by Phorbol-Myristate-Acetate plus Ionomycin (PMA+Io. On the other hand, short interference RNA (siRNA-mediated silencing of ACSL5 decreased induced apoptosis in Jurkat T cells up to the control levels as well as decreased mRNA expression of FAS, FASLG and TNF. CONCLUSIONS: These findings indicate that ACSL5 may play a role in the apoptosis that takes place in SLE. Our results point to ACSL5 as a potential novel functional marker of pathogenesis and a possible therapeutic target in SLE.

  3. Hereditary neurometabolic causes of infantile spasms in 80 children presenting to a tertiary care center.

    Science.gov (United States)

    Alrifai, Muhammad Talal; AlShaya, Mohammed Abdullah; Abulaban, Ahmad; Alfadhel, Majid

    2014-09-01

    Infantile spasms are a devastating infantile epileptic syndrome with multiple etiologies. Hereditary neurometabolic disorders are rarely recognized causes of infantile spasms. The aim of this study was to identify hereditary neurometabolic disorders when they were the cause of infantile spasms in patients presenting to a tertiary care center in Saudi Arabia. We conducted a retrospective review of children presenting to the Pediatric Department of King Abdulaziz Medical City in Riyadh, Saudi Arabia over a 15-year interval. Eighty patients with infantile spasms were identified. A hereditary neurometabolic disorder was diagnosed in 10 patients (12.5%). Of these patients, two had a Leigh-like disorder and one patient had each of the following diagnoses: ethylmalonic aciduria, nonketotic hyperglycinemia, hyperinsulinemic hypoglycemia, leukodystrophy, short-chain acyl-coenzyme A dehydrogenase deficiency, molybdenum cofactor deficiency, primary carnitine deficiency, and neonatal hypoglycemia due to panhypopituitarism. This article is the first to report the association of the last three conditions with infantile spasms. Compared with the other etiologies, the hereditary neurometabolic disorder group had a strong history of similar disease in the same family (P = 0.002), and most of the patients were born of consanguineous parents (P = 0.021). In addition, a typical hypsarrhythmia pattern was more common in the hereditary neurometabolic disorder group (P = 0.003). Furthermore, this group had a poor response to therapy (P = 0.04). Otherwise, there were no significant differences regarding the type of spasms, neuroimaging or outcome; however, there was a trend toward poorer outcomes and death in the hereditary neurometabolic disorder group. Hereditary neurometabolic disorders are relatively common causes of infantile spasms in this subpopulation of Saudi patients. An early diagnosis via proper metabolic and genetic testing has significant implications for applying specific

  4. Hepatic lipid metabolic pathways modified by resveratrol in rats fed an obesogenic diet.

    Science.gov (United States)

    Alberdi, Goiuri; Rodríguez, Víctor M; Macarulla, M Teresa; Miranda, Jonatan; Churruca, Itziar; Portillo, María P

    2013-03-01

    The scientific community is on the look-out for safe biomolecules useful in the prevention of obesity and related aberrations such as fatty liver. This study analyzed the influence of resveratrol on hepatic triacylglycerol metabolism. Male Sprague-Dawley rats were divided into control and resveratrol-treated groups (30 mg/kg of body weight per day) and fed a commercial obesogenic diet for 6 wk. Liver triacylglycerol content and the activity of carnitine palmitoyl transferase-Ia (CPT-Ia), acyl-coenzyme A oxydase (ACO), fatty acid synthase (FAS), glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (ME), acetyl-coenzyme A carboxylase (ACC), adenosine monophosphate-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) activation were measured. Mitochondrial protein cytochrome C oxidase subunit 2 (COXII), mitochondrial transcription factor A (TFAM), sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-α (PPAR-α), sirtuin-1 (SIRT1), hepatocyte nuclear factor receptor-4α (HNF-4α), and PGC-1α mRNA levels were also analyzed. Serum insulin was quantified. Resveratrol decreased liver fat accumulation, increased CPT-Ia and ACO, and decreased ACC activities. Other lipogenic enzymes, FAS, ME, and G6PDH were not modified. The polyphenol activated AMPK and PGC-1α. The expression of SRBP-1c, PPAR-α, SIRT1, PGC-1α, HNF-4α, TFAM, and COXII was not modified. No changes in serum insulin levels were observed. Resveratrol partly prevents the increase in liver fat accumulation induced by high-fat high-sucrose feeding by increasing fatty acid oxidation and decreasing lipogenesis. These effects are mediated by the activation of the AMPK/SIRT1 axis. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Retinal Hypercholesterolemia Triggers Cholesterol Accumulation and Esterification in Photoreceptor Cells*

    Science.gov (United States)

    Saadane, Aicha; Mast, Natalia; Dao, Tung; Ahmad, Baseer; Pikuleva, Irina A.

    2016-01-01

    The process of vision is impossible without the photoreceptor cells, which have a unique structure and specific maintenance of cholesterol. Herein we report on the previously unrecognized cholesterol-related pathway in the retina discovered during follow-up characterizations of Cyp27a1−/−Cyp46a1−/− mice. These animals have retinal hypercholesterolemia and convert excess retinal cholesterol into cholesterol esters, normally present in the retina in very small amounts. We established that in the Cyp27a1−/−Cyp46a1−/− retina, cholesterol esters are generated by and accumulate in the photoreceptor outer segments (OS), which is the retinal layer with the lowest cholesterol content. Mouse OS were also found to express the cholesterol-esterifying enzyme acyl-coenzyme A:cholesterol acyltransferase (ACAT1), but not lecithin-cholesterol acyltransferase (LCAT), and to differ from humans in retinal expression of ACAT1. Nevertheless, cholesterol esters were discovered to be abundant in human OS. We suggest a mechanism for cholesterol ester accumulation in the OS and that activity impairment of ACAT1 in humans may underlie the development of subretinal drusenoid deposits, a hallmark of age-related macular degeneration, which is a common blinding disease. We generated Cyp27a1−/−Cyp46a1−/−Acat1−/− mice, characterized their retina by different imaging modalities, and confirmed that unesterified cholesterol does accumulate in their OS and that there is photoreceptor apoptosis and OS degeneration in this line. Our results provide insights into the retinal response to local hypercholesterolemia and the retinal significance of cholesterol esterification, which could be cell-specific and both beneficial and detrimental for retinal structure and function. PMID:27514747

  6. Lipidomic and spatio-temporal imaging of fat by mass spectrometry in mice duodenum during lipid digestion.

    Directory of Open Access Journals (Sweden)

    Alexandre Seyer

    Full Text Available Intestinal absorption of dietary fat is a complex process mediated by enterocytes leading to lipid assembly and secretion of circulating lipoproteins as chylomicrons, vLDL and intestinal HDL (iHDL. Understanding lipid digestion is of importance knowing the correlation between excessive fat absorption and atherosclerosis. By using time-of-flight secondary ion mass spectrometry (TOF-SIMS, we illustrated a spatio-temporal localization of fat in mice duodenum, at different times of digestion after a lipid gavage, for the first time. Fatty acids progressively increased in enterocytes as well as taurocholic acid, secreted by bile and engaged in the entero-hepatic re-absorption cycle. Cytosolic lipid droplets (CLD from enterocytes were originally purified separating chylomicron-like, intermediate droplets and smaller HDL-like. A lipidomic quantification revealed their contents in triglycerides, free and esterified cholesterol, phosphatidylcholine, sphingomyelin and ceramides but also in free fatty acids, mono- and di-acylglycerols. An acyl-transferase activity was identified and the enzyme monoacylglycerol acyl transferase 2 (MGAT2 was immunodetected in all CLD. The largest droplets was also shown to contain the microsomal triglyceride transfer protein (MTTP, the acyl-coenzyme A-cholesterol acyltransferases (ACAT 1 and 2, hormone sensitive lipase (HSL and adipose triglyceride lipase (ATGL. This highlights the fact that during the digestion of fats, enterocyte CLD contain some enzymes involved in the different stages of the metabolism of diet fatty acids and cholesterol, in anticipation of the crucial work of endoplasmic reticulum in the process. The data further underlines the dual role of chylomicrons and iHDL in fat digestion which should help to efficiently complement lipid-lowering therapy.

  7. Development of ATX and DUSP inhibitors : inhibiting phosphate ester hydrolysis in biology

    NARCIS (Netherlands)

    Albers, Harald Matheas Henricus Gerardus

    2012-01-01

    The first part of this thesis describes the development of inhibitors of autotaxin (ATX or ENPP2), a phosphodiesterase that is responsible for the production of the lipid lysophosphatidic acid (LPA) in the circulation. ATX is implicated in several diseases including inflammation, fibrotic disease

  8. Production of LPA by autotaxin and toxic phospholipases D : biochemical characterization and physiological implications

    NARCIS (Netherlands)

    Meeteren, Laurens Arend van

    2007-01-01

    Lysophosphatidic acid (LPA) is a lipid mediator with a wide variety of biological actions, particularly as an inducer of cell proliferation, migration and survival. LPA binds to at least five distinct G protein-coupled receptors and thereby activates multiple signal transduction pathways, including

  9. Autotaxin : biochemical and functional studies

    NARCIS (Netherlands)

    Houben, Anna Jacoba Sara

    2012-01-01

    This thesis focuses on autotaxin (ATX), the main enzyme responsible for the production of lysophosphatidic acid (LPA). The ATX-LPA receptor axis has a wide implication in health and disease. The studies described in this thesis aim at characterizing the biochemical and functional properties of ATX,

  10. Journal of Biosciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Lysophosphatidyl acyltransferase (LPAT) is the important enzyme responsible for the acylation of lysophosphatidic acid (LPA), leading to the generation of phosphatidic acid (PA) in plant. Its encoding gene is an essential candidate for oil crops to improve oil composition and increase seed oil content through genetic ...

  11. Gi-mediated activation of the Ras/MAP kinase pathway involves a 100 kDa tyrosine-phosphorylated Grb2 SH3 binding protein, but not Src nor Shc

    NARCIS (Netherlands)

    Kranenburg, O.; Verlaan, I.; Hordijk, P. L.; Moolenaar, W. H.

    1997-01-01

    Mitogenic G protein-coupled receptors, such as those for lysophosphatidic acid (LPA) and thrombin, activate the Ras/MAP kinase pathway via pertussis toxin (PTX)-sensitive Gi, tyrosine kinase activity and recruitment of Grb2, which targets guanine nucleotide exchange activity to Ras. Little is known

  12. to view fulltext PDF

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    Although originally described as an intracellular second messenger, sphingosine 1-phosphate (S1P) has recently been shown to ... lysophosphatidic acid; LPS, lipopolysaccharides; mDC, mature DC; MHC, major histocompatibility complex; NK, natural killer; PCR, ..... -the enigmatic lipid class: biochemistry, physiology, and.

  13. Define the Twist-ATX-LPAR1 Signaling Axis in Promoting Obesity Associated Triple Negative Breast Cancer

    Science.gov (United States)

    2017-05-01

    ps ) 14:0 16:0 17:0 18:0 18:1 20:4 Figure 8 Measurement of Lysophosphatidic acid by tandem mass spectrometry. The indicated LPA species were...the universities and scientific conferences in the past 12 months. Research presentations made by Dr. Morris Feb 26-March 2 2017 Keystone Conference

  14. WDR26 in Advanced Breast Cancer: A Novel Regulator of the P13K/AKT Pathway

    Science.gov (United States)

    2016-10-01

    development [6]. In addition, PTEN- deficient breast tumor cells require PI3Kβ (but not PI3Kα) to proliferate, and are more sensitive to cell-cycle arrest ...Chun J, Nusrat A, Yun CC. Distinct phospholipase C-beta isozymes mediate lysophosphatidic acid receptor 1 effects on intestinal epithelial

  15. Multidisciplinary Strategies in the Prevention and Early Detection of Ovarian Cancer

    Science.gov (United States)

    2001-09-01

    smooth muscle cells in culture. Thrombosis Res WH. Lysophosphatidic acid induces neuronal shape changes via 1999;94:317-26. a novel receptor-mediated...lgara.shi Y. Sphingosine gosylphosphorylcholine constrict renal and mesenteric mai- i-phosphate a specific endogenous signaling molecule control

  16. Mammalian farnesyltransferase α subunit regulates vacuolar protein sorting-associated protein 4A (Vps4A)--dependent intracellular trafficking through recycling endosomes.

    Science.gov (United States)

    Kubala, Marta H; Norwood, Suzanne J; Gomez, Guillermo A; Jones, Alun; Johnston, Wayne; Yap, Alpha S; Mureev, Sergey; Alexandrov, Kirill

    2015-12-25

    The protein farnesyltransferase (FTase) mediates posttranslational modification of proteins with isoprenoid lipids. FTase is a heterodimer and although the β subunit harbors the active site, it requires the α subunit for its activity. Here we explore the other functions of the FTase α subunit in addition to its established role in protein prenylation. We found that in the absence of the β subunit, the α subunit of FTase forms a stable autonomous dimeric structure in solution. We identify interactors of FTase α using mass spectrometry, followed by rapid in vitro analysis using the Leishmania tarentolae cell - free system. Vps4A was validated for direct binding to the FTase α subunit both in vitro and in vivo. Analysis of the interaction with Vps4A in Hek 293 cells demonstrated that FTase α controls trafficking of transferrin receptor upstream of this protein. These results point to the existence of previously undetected biological functions of the FTase α subunit that includes control of intracellular membrane trafficking. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Predictive role of caregiver type, dependency level and time caring on the impact of caring for a dependent relative as a stressor

    OpenAIRE

    Teresa Lanzón Serra; Amelia Díaz Martínez

    2014-01-01

    El trabajo presenta la evaluación de sintomatología de estrés asociada a la tarea de cuidar a un familiar dependiente en el hogar. Se estudia el papel que desempeñan variables como el tipo de cuidador (enfermero/no enfermero), nivel de dependencia de la persona cuidada, horas al día de cuidado y años que se lleva cuidando al familiar. La muestra está compuesta por 100 cuidadores y las variables asociadas a estrés son intrusión, evitación y activación. Los resultados indican que los no enferme...

  18. Postmortem determination of concentrations of stress hormones in various body fluids--is there a dependency between adrenaline/noradrenaline quotient, cause of death and agony time?

    Science.gov (United States)

    Wilke, N; Janssen, H; Fahrenhorst, C; Hecker, H; Manns, M P; Brabant, E-G; Tröger, H D; Breitmeier, D

    2007-09-01

    To find out whether a certain cause of death or a certain length of an agonal period shows specific adrenaline or noradrenaline profiles, heart blood, femoral vein blood, liquor, urine and vitreous humour were taken from corpses (n = 98) at the Medical School Hannover, and noradrenaline and adrenaline were determined using high-performance liquid chromatography (HPLC). Corpses were classified according to the following five categories: short agony, long agony, state after hanging, state after asphyxiation and state after CPR with documented administration of epinephrine. Once results were collected the adrenaline/noradrenaline quotient was determined. It became clear that there were no significant differences regarding the concentration of adrenaline and noradrenaline in the various body fluids in relation to the above-mentioned categories. The means adrenaline/noradrenaline quotients in femoral vein blood were 0.21 +/- 0.29 for hanged persons, 0.38 +/- 0.47 for asphyxiated persons, 0.17 +/- 0.19 for those with short agony and 0.42 +/- 0.43 for those with long agony, significantly below 1 (p agony was 0.17 +/- 0.17, for hanged persons 0.18 +/- 0.19 and for asphyxiated ones 0.30 +/- 0.38, significantly lower than 1 (p agony (0.13 +/- 0.09), long agony (0.21 +/- 0.16), hanged (0.15 +/- 0.16), asphyxiated (0.14 +/- 0.08) and CPR (0.14 +/- 0.06). In vitreous humour the quotients for short agony (0.14 +/- 0.28), long agony (0.13 +/- 0.12), hanged (0.07 +/- 0.09) and asphyxiated (0.09 +/- 0.11) are lower than 1 (p agony in individual cases.

  19. The mitogen-activated protein kinase pathway mediates growth arrest or E1A-dependent apoptosis in SKBR3 human breast cancer cells.

    Science.gov (United States)

    Blagosklonny, M V

    1998-11-09

    Previously, we have shown that phorbol ester (PMA) induces p21(WAF1/CIP1)-dependent growth arrest in SKBr3 breast cancer and LNCaP prostate cancer cells. Here, I demonstrate that inhibition of Raf-1 kinase by dominant-negative Raf-1 or pharmacological depletion of Raf-1 prevented PMA-mediated induction of p21(WAF1/CIP1). Similarly, PD98059, a specific inhibitor of MEK, abolished p21(WAF1/CIP1) induction and PMA-induced growth arrest. Like PMA, the H-ras oncogene, another activator of the Raf-1/MEK/MAPK pathway, transactivated p21(WAF1/CIP1) in SKBr3 cells. I further investigated PMA-induced growth arrest following infection of SKBr3 cells with 12S E1A-expressing adenovirus. Although high levels of E1A oncoprotein prevented both PMA-induced p21(WAF1/CIP1) and growth arrest, smaller amounts of E1A abrogated growth arrest without down-regulation of p21(WAF1/CIP1). Therefore, E1A can stimulate proliferation downstream of p21(WAF1/CIP1). Albeit less effective than full activity, either Rb- or p300-binding activity of E1A was sufficient for the abrogation of PMA-mediated growth arrest. E1A-driven proliferation of PMA-treated SKBr3 cells was accompanied by apoptosis. New therapeutic approaches can be envisioned that would utilize stimulation of the Raf-1/MEK/MAPK pathway to inhibit growth of PMA-sensitive cancer cells.

  20. Morphologic transformation of human breast epithelial cells MCF-10A: dependence on an oxidative microenvironment and estrogen/epidermal growth factor receptors

    Directory of Open Access Journals (Sweden)

    Yusuf Rita

    2010-09-01

    Full Text Available Abstract Background MCF-10A, immortalized but non-transformed human breast epithelial cells, are widely used in research examining carcinogenesis. The studies presented here were initiated with the observation that MCF-10A cells left in continuous culture for prolonged periods without re-feeding were prone to the development of transformed foci. We hypothesized that the depletion of labile culture components led to the onset of processes culminating in the observed cell transformation. The purpose of this study was to define the factors which promoted transformation of this cell line. Results Changes in levels of phenol red (PHR, hydrocortisone (HC, and epidermal growth factor (EGF with or without estrogen treatment indicated that both oxidative stress- and estrogen receptor alpha (ERα-mediated pathways contribute to cell transformation. Gene array and Western blotting analyses of cells maintained in our laboratory and of those from other sources documented detectable ERα and ERbeta (ERβ in this ERα-negative cataloged cell line. Results also indicate the possibility of a direct association of EGF receptor (EGFR and ERα in these cells as well as the formation and high induction of a novel ternary complex that includes ERβ (ERα/ERβ/EGFR in cells grown under conditions facilitating transformation. Conclusions Our studies resulted in the development of a growth protocol where the effects of chronic, physiologically relevant alterations in the microenvironment on cellular transformation were examined. From our results, we were able to propose a model of transformation within the MCF-10A cell line in which oxidative stress, ER and EGFR play essential roles. Overall, our work indicates that the immediate microenvironment of cells exerts powerful growth cues which ultimately determine their transformation potential.

  1. Natural Killer Cell-Mediated Host Defense against Uropathogenic E. coli Is Counteracted by Bacterial HemolysinA-Dependent Killing of NK Cells

    Science.gov (United States)

    Gur, Chamutal; Coppenhagen-Glazer, Shunit; Rosenberg, Shilo; Yamin, Rachel; Enk, Jonatan; Glasner, Ariella; Bar-On, Yotam; Fleissig, Omer; Naor, Ronit; Abed, Jawad; Mevorach, Dror; Granot, Zvi; Bachrach, Gilad; Mandelboim, Ofer

    2013-01-01

    SUMMARY Uropathogenic Escherichia coli (UPEC) are a common cause of urinary tract infections (UTIs) in humans. While the importance of natural killer (NK) cells in innate immune protection against tumors and viral infections is well documented, their role in defense against bacterial infections is still emerging, and their involvement in UPEC-mediated UTI is practically unknown. Using a systematic mutagenesis approach, we found that UPEC adheres to NK cells primarily via its type I fimbriae and employs its hemolysinA toxin to kill NK cells. In the absence of hemolysinA, NK cells directly respond to the bacteria and secrete the cytokine TNF-α, which results in decreased bacterial numbers in vitro and reduction of bacterial burden in the infected bladders. Thus, NK cells control UPEC via TNF-α production, which UPEC counteracts by hemolysinA-mediated killing of NK cells, representing a previously unrecognized host defense and microbial counterattack mechanism in the context of UTI. PMID:24331464

  2. COMPARISON OF POND AND RACEWAY PRODUCTION METHODS ON TEXTURE OF CHANNEL CATFISH (Ictalurus punctatus) FILLETS, SHOWING A DEPENDENCY ON SIZE AND FILLET POSITION

    Science.gov (United States)

    The objective of this study was to compare the effect of the production environment (pond vs in-pond raceway) on the chemical composition, color, and textural properties of channel catfish fillets. Compositional analysis consisted of percent moisture, lipid, protein, and ash content. Additional sa...

  3. Self-Management as a Class-Wide Intervention: An Evaluation of the "Self & Match" System Embedded within a Dependent Group Contingency

    Science.gov (United States)

    Bulla, Andrew J.

    2017-01-01

    The U.S. Department of Education (2015) indicated that about 95% of students with special education eligibility receive some form of education in the general education setting. Students with disabilities tend to engage in more disruptive behaviors than their non-disabled peers (e.g., Murphy, Beadle-Brown, Wing, Gould, Shah, & Homes, 2005). If…

  4. Analysis of bacteria by pyrolysis gas chromatography-differential mobility spectrometry and isolation of chemical components with a dependence on growth temperature.

    Science.gov (United States)

    Prasad, Satendra; Pierce, Karisa M; Schmidt, Hartwig; Rao, Jaya V; Güth, Robert; Bader, Sabine; Synovec, Robert E; Smith, Geoffrey B; Eiceman, Gary A

    2007-10-01

    Pyrolysis gas chromatography-differential mobility spectrometry (py-GC-DMS) analysis of E. coli, P. aeruginosa, S. warneri and M. luteus, grown at temperatures of 23, 30, and 37 degrees C, provided data sets of ion intensity, retention time, and compensation voltage for principal component analysis. Misaligned chromatographic axes were treated using piecewise alignment, the impact on the degree of class separation (DCS) of clusters was minor. The DCS, however, was improved between 21 to 527% by analysis of variance with Fisher ratios to remove chemical components independent of growth temperature. The temperature dependent components comprised 84% of all peaks in the py-GC-DMS analysis of E. coli and were attributed to the pyrolytic decomposition of proteins rather than lipids, as anticipated. Components were also isolated in other bacteria at differing amounts: 41% for M. luteus, 14% for P. aeruginosa, and 4% for S. warneri, and differing patterns suggested characteristic dependence on temperature of growth for these bacteria. These components are anticipated to have masses from 100 to 200 Da by inference from differential mobility spectra.

  5. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons

    International Nuclear Information System (INIS)

    Sadler, M.E.; Isenhower, L.D.

    1992-01-01

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments

  6. Honokiol abrogates leptin-induced tumor progression by inhibiting Wnt1-MTA1-β-catenin signaling axis in a microRNA-34a dependent manner.

    Science.gov (United States)

    Avtanski, Dimiter B; Nagalingam, Arumugam; Kuppusamy, Panjamurthy; Bonner, Michael Y; Arbiser, Jack L; Saxena, Neeraj K; Sharma, Dipali

    2015-06-30

    Obesity greatly influences risk, progression and prognosis of breast cancer. As molecular effects of obesity are largely mediated by adipocytokine leptin, finding effective novel strategies to antagonize neoplastic effects of leptin is desirable to disrupt obesity-cancer axis. Present study is designed to test the efficacy of honokiol (HNK), a bioactive polyphenol from Magnolia grandiflora, against oncogenic actions of leptin and systematically elucidate the underlying mechanisms. Our results show that HNK significantly inhibits leptin-induced breast-cancer cell-growth, invasion, migration and leptin-induced breast-tumor-xenograft growth. Using a phospho-kinase screening array, we discover that HNK inhibits phosphorylation and activation of key molecules of leptin-signaling-network. Specifically, HNK inhibits leptin-induced Wnt1-MTA1-β-catenin signaling in vitro and in vivo. Finally, an integral role of miR-34a in HNK-mediated inhibition of Wnt1-MTA1-β-catenin axis was discovered. HNK inhibits Stat3 phosphorylation, abrogates its recruitment to miR-34a promoter and this release of repressor-Stat3 results in miR-34a activation leading to Wnt1-MTA1-β-catenin inhibition. Accordingly, HNK treatment inhibited breast tumor growth in diet-induced-obese mouse model (exhibiting high leptin levels) in a manner associated with activation of miR-34a and inhibition of MTA1-β-catenin. These data provide first in vitro and in vivo evidence for the leptin-antagonist potential of HNK revealing a crosstalk between HNK and miR34a and Wnt1-MTA1-β-catenin axis.

  7. Group psycho-education in patients with bipolar disorder associated with a dependency of toxic substances in patients who are in abstinence

    Directory of Open Access Journals (Sweden)

    Patricia González Alegre

    2009-01-01

    Full Text Available The high comorbility that exists among psychiatric disorders and addictive is important. In the latest years it is produced an increase of the sensibility related to this problem. A great deal it is due to the demand of Mental Health Services and also due to drug dependency, as a consequence of the lack of an integral approach. Because of this fact and because of the mentioned demand, we though it should be pertinent developing a research project in order to check if the carrying the psycho-educative preventive group project out in patients with a diagnose of bipolar disorder with an abuse of drugs history and/or dependency of toxic substance in abstinence at the moment influents in a positive way in the course of the number of relapses in the toxic consumption during at least six months subsequent to the intervention. And at this way, these patients will purchase a greater consciousness of the important of healthy habits in the bipolar disorder and the recovery in the toxic substance abuse. The program will be developed in an experimental research where the patients will be randomly assigned in group control/ experimentally, the intervention will last twenty sessions, each session will be an hour and a half long and will be held weekly. In these sessions we will deal with topics related to the psychiatric disorder and the toxic consume. At the same time we will bank on the development of practical relaxation workshops on in some of the sessions with the object of providing a resource in view of stress situations.

  8. On-Chip Scan-Based Test Strategy for a Dependable Many-Core Processor Using a NoC as a Test Access Mechanism

    NARCIS (Netherlands)

    Zhang, X.; Kerkhoff, Hans G.; Vermeulen, Bart

    2010-01-01

    Periodic on-chip scan-based tests have to be applied to a many-core processor SoC to improve its dependability. An infrastructural IP module has been designed and incorporated into the SoC to function as an ATE. This paper introduces the reuse of a Network-on-Chip as a test access mechanism. Since

  9. Tfap2a-dependent changes in mouse facial morphology result in clefting that can be ameliorated by a reduction in Fgf8 gene dosage

    Directory of Open Access Journals (Sweden)

    Rebecca M. Green

    2015-01-01

    Full Text Available Failure of facial prominence fusion causes cleft lip and palate (CL/P, a common human birth defect. Several potential mechanisms can be envisioned that would result in CL/P, including failure of prominence growth and/or alignment as well as a failure of fusion of the juxtaposed epithelial seams. Here, using geometric morphometrics, we analyzed facial outgrowth and shape change over time in a novel mouse model exhibiting fully penetrant bilateral CL/P. This robust model is based upon mutations in Tfap2a, the gene encoding transcription factor AP-2α, which has been implicated in both syndromic and non-syndromic human CL/P. Our findings indicate that aberrant morphology and subsequent misalignment of the facial prominences underlies the inability of the mutant prominences to fuse. Exencephaly also occured in some of the Tfap2a mutants and we observed additional morphometric differences that indicate an influence of neural tube closure defects on facial shape. Molecular analysis of the CL/P model indicates that Fgf signaling is misregulated in the face, and that reducing Fgf8 gene dosage can attenuate the clefting pathology by generating compensatory changes. Furthermore, mutations in either Tfap2a or Fgf8 increase variance in facial shape, but the combination of these mutations restores variance to normal levels. The alterations in variance provide a potential mechanistic link between clefting and the evolution and diversity of facial morphology. Overall, our findings suggest that CL/P can result from small gene-expression changes that alter the shape of the facial prominences and uncouple their coordinated morphogenesis, which is necessary for normal fusion.

  10. New scan-based test strategy for a dependable many-core processor using a NoC as a Test Access Mechanism

    NARCIS (Netherlands)

    Zhang, X.; Kerkhoff, Hans G.; Vermeulen, Bart

    2010-01-01

    Periodic on-chip scan-based tests have to be applied to a many-core processor to improve its dependability. This paper describes an infrastructural IP module that has been designed and incorporated into an SoC to function as an ATE. The Network-on-Chip inside the SoC is reused as a test access

  11. Glucose triggers protein kinase A-dependent insulin secretion in mouse pancreatic islets through activation of the K+ATP channel-dependent pathway

    DEFF Research Database (Denmark)

    Thams, Peter; Anwar, Mohammad R; Capito, Kirsten

    2005-01-01

    OBJECTIVE: To assess the significance of protein kinase A (PKA) in glucose triggering of ATP-sensitive K(+) (K(+)(ATP)) channel-dependent insulin secretion and in glucose amplification of K(+)(ATP) channel-independent insulin secretion. METHODS: Insulin release from cultured perifused mouse...... pancreatic islets was determined by radioimmunoassay. RESULTS: In islets cultured at 5.5 mmol/l glucose, and then perifused in physiological Krebs-Ringer medium, the PKA inhibitors, H89 (10 micromol/l) and PKI 6-22 amide (30 micromol/l) did not inhibit glucose (16.7 mmol/l)-induced insulin secretion...... glucose amplification of K(+)(ATP) channel-independent insulin secretion. In the presence of 1 mmol/l ouabain and 250 micromol/l diazoxide, which cause modest Ca(2+) influx, glucose amplification of K(+)(ATP) channel-independent insulin secretion was observed without concomitant Ca(2+) stimulation of PKA...

  12. Protein kinase A-dependent Neuronal Nitric Oxide Synthase Activation Mediates the Enhancement of Baroreflex Response by Adrenomedullin in the Nucleus Tractus Solitarii of Rats

    Directory of Open Access Journals (Sweden)

    Ho I-Chun

    2011-05-01

    Full Text Available Abstract Background Adrenomedullin (ADM exerts its biological functions through the receptor-mediated enzymatic mechanisms that involve protein kinase A (PKA, or neuronal nitric oxide synthase (nNOS. We previously demonstrated that the receptor-mediated cAMP/PKA pathway involves in ADM-enhanced baroreceptor reflex (BRR response. It remains unclear whether ADM may enhance BRR response via activation of nNOS-dependent mechanism in the nucleus tractus solitarii (NTS. Methods Intravenous injection of phenylephrine was administered to evoke the BRR before and at 10, 30, and 60 min after microinjection of the test agents into NTS of Sprague-Dawley rats. Western blotting analysis was used to measure the level and phosphorylation of proteins that involved in BRR-enhancing effects of ADM (0.2 pmol in NTS. The colocalization of PKA and nNOS was examined by immunohistochemical staining and observed with a laser confocal microscope. Results We found that ADM-induced enhancement of BRR response was blunted by microinjection of NPLA or Rp-8-Br-cGMP, a selective inhibitor of nNOS or protein kinase G (PKG respectively, into NTS. Western blot analysis further revealed that ADM induced an increase in the protein level of PKG-I which could be attenuated by co-microinjection with the ADM receptor antagonist ADM22-52 or NPLA. Moreover, we observed an increase in phosphorylation at Ser1416 of nNOS at 10, 30, and 60 min after intra-NTS administration of ADM. As such, nNOS/PKG signaling may also account for the enhancing effect of ADM on BRR response. Interestingly, biochemical evidence further showed that ADM-induced increase of nNOS phosphorylation was prevented by co-microinjection with Rp-8-Br-cAMP, a PKA inhibitor. The possibility of PKA-dependent nNOS activation was substantiated by immunohistochemical demonstration of co-localization of PKA and nNOS in putative NTS neurons. Conclusions The novel finding of this study is that the signal transduction cascade that underlies the enhancement of BRR response by ADM in NTS is composed sequentially of cAMP/PKA and nNOS/PKG pathways.

  13. Protein kinase a dependent phosphorylation of apical membrane antigen 1 plays an important role in erythrocyte invasion by the malaria parasite.

    Directory of Open Access Journals (Sweden)

    Kerstin Leykauf

    2010-06-01

    Full Text Available Apicomplexan parasites are obligate intracellular parasites that infect a variety of hosts, causing significant diseases in livestock and humans. The invasive forms of the parasites invade their host cells by gliding motility, an active process driven by parasite adhesion proteins and molecular motors. A crucial point during host cell invasion is the formation of a ring-shaped area of intimate contact between the parasite and the host known as a tight junction. As the invasive zoite propels itself into the host-cell, the junction moves down the length of the parasite. This process must be tightly regulated and signalling is likely to play a role in this event. One crucial protein for tight-junction formation is the apical membrane antigen 1 (AMA1. Here we have investigated the phosphorylation status of this key player in the invasion process in the human malaria parasite Plasmodium falciparum. We show that the cytoplasmic tail of P. falciparum AMA1 is phosphorylated at serine 610. We provide evidence that the enzyme responsible for serine 610 phosphorylation is the cAMP regulated protein kinase A (PfPKA. Importantly, mutation of AMA1 serine 610 to alanine abrogates phosphorylation of AMA1 in vivo and dramatically impedes invasion. In addition to shedding unexpected new light on AMA1 function, this work represents the first time PKA has been implicated in merozoite invasion.

  14. Tauroursodeoxycholate Protects Rat Hepatocytes from Bile Acid-Induced Apoptosis via β1-Integrin- and Protein Kinase A-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Annika Sommerfeld

    2015-05-01

    Full Text Available Background/Aims: Ursodeoxycholic acid, which in vivo is rapidly converted into its taurine conjugate, is frequently used for the treatment of cholestatic liver disease. Apart from its choleretic effects, tauroursodeoxycholate (TUDC can protect hepatocytes from bile acid-induced apoptosis, but the mechanisms underlying its anti-apoptotic effects are poorly understood. Methods: These mechanisms were investigated in perfused rat liver and isolated rat hepatocytes. Results: It was found that TUDC inhibited the glycochenodeoxycholate (GCDC-induced activation of the CD95 death receptor at the level of association between CD95 and the epidermal growth factor receptor. This was due to a rapid TUDC-induced β1-integrin-dependent cyclic AMP (cAMP signal with induction of the dual specificity mitogen-activated protein (MAP kinase phosphatase 1 (MKP-1, which prevented GCDC-induced phosphorylation of mitogen-activated protein kinase kinase 4 (MKK4 and c-jun-NH2-terminal kinase (JNK activation. Furthermore, TUDC induced a protein kinase A (PKA-mediated serine/threonine phosphorylation of the CD95, which was recently identified as an internalization signal for CD95. Furthermore, TUDC inhibited GCDC-induced CD95 targeting to the plasma membrane in a β1-integrin-and PKA-dependent manner. In line with this, the β1-integrin siRNA knockdown in sodium taurocholate cotransporting polypeptide (Ntcp-transfected HepG2 cells abolished the protective effect of TUDC against GCDC-induced apoptosis. Conclusion: TUDC exerts its anti-apoptotic effect via a β1-integrin-mediated formation of cAMP, which prevents CD95 activation by hydrophobic bile acids at the levels of JNK activation and CD95 serine/threonine phosphorylation.

  15. Prostaglandin E1 protects hepatocytes against endoplasmic reticulum stress-induced apoptosis via protein kinase A-dependent induction of glucose-regulated protein 78 expression.

    Science.gov (United States)

    Yang, Fang-Wan; Fu, Yu; Li, Ying; He, Yi-Huai; Mu, Mao-Yuan; Liu, Qi-Chuan; Long, Jun; Lin, Shi-De

    2017-10-28

    To investigate the protective effect of prostaglandin E1 (PGE1) against endoplasmic reticulum (ER) stress-induced hepatocyte apoptosis, and to explore its underlying mechanisms. Thapsigargin (TG) was used to induce ER stress in the human hepatic cell line L02 and hepatocarcinoma-derived cell line HepG2. To evaluate the effects of PGE1 on TG-induced apoptosis, PGE1 was used an hour prior to TG treatment. Activation of unfolded protein response signaling pathways were detected by western blotting and quantitative real-time RT-PCR. Apoptotic index and cell viability of L02 cells and HepG2 cells were determined with flow cytometry and MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. Pretreatment with 1 μmol/L PGE1 protected against TG-induced apoptosis in both L02 cells and HepG2 cells. PGE1 enhanced the TG-induced expression of C/EBP homologous protein (CHOP), glucose-regulated protein (GRP) 78 and spliced X box-binding protein 1 at 6 h. However, it attenuated their expressions after 24 h. PGE1 alone induced protein and mRNA expressions of GRP78; PGE1 also induced protein expression of DNA damage-inducible gene 34 and inhibited the expressions of phospho-PKR-like ER kinase, phospho-eukaryotic initiation factor 2α and CHOP. Treatment with protein kinase A (PKA)-inhibitor H89 or KT5720 blocked PGE1-induced up-regulation of GRP78. Further, the cytoprotective effect of PGE1 on hepatocytes was not observed after blockade of GRP78 expression by H89 or small interfering RNA specifically targeted against human GRP78. Our study demonstrates that PGE1 protects against ER stress-induced hepatocyte apoptosis via PKA pathway-dependent induction of GRP78 expression.

  16. The crosstalk between breast carcinoma-associated fibroblasts and cancer cells promotes RhoA-dependent invasionviaIGF-1 and PAI-1.

    Science.gov (United States)

    Daubriac, Julien; Han, Shiwei; Grahovac, Jelena; Smith, Eve; Hosein, Abdel; Buchanan, Marguerite; Basik, Mark; Boucher, Yves

    2018-02-13

    Carcinoma-associated fibroblasts (CAFs) can remodel the extracellular matrix to promote cancer cell invasion, but the paracrine signaling between CAFs and cancer cells that regulates tumor cell migration remains to be identified. To determine how the interaction between CAFs and cancer cells modulates the invasiveness of cancer cells, we developed a 3-dimensional co-culture model composed of breast cancer (BC) MDA-MB-231 cell spheroids embedded in a collagen gel with and without CAFs. We found that the crosstalk between CAFs and cancer cells promotes invasion by stimulating the scattering of MDA-MB-231 cells, which was dependent on RhoA/ROCK/phospho MLC signaling in cancer cells but independent of RhoA in CAFs. The activation of RhoA/ROCK in cancer cells activates MLC and increases migration, while the genetic-down-regulation of RhoA and pharmacological inhibition of ROCK reduced cell scattering and invasion. Two distinct mechanisms induced the activation of the RhoA/ROCK pathway in MDA-MB-231 cells, the secretion of IGF-1 by CAFs and the upregulation of PAI-1 in cancer cells. In an orthotopic model of BC, IGF-1R inhibition decreased the incidence of lung metastasis, while Y27632-inhibition of ROCK enhanced the lung metastasis burden, which was associated with an increased recruitment of CAFs and expression of PAI-1. Thus the crosstalk between CAFs and BC cells increases the secretion of IGF-1 in CAFs and PAI-1 activity in cancer cells. Both IGF1 and PAI-1 activate RhoA/ROCK signaling in cancer cells, which increases cell scattering and invasion.

  17. Signal-on CoA-dependent electrochemical biosensor for highly sensitive and label-free detection of Citrate synthase activity.

    Science.gov (United States)

    Wang, Qin; Chen, Hongjun; Li, Yong; Wang, Huixia; Nie, Zhou; Hu, Yufang; Yao, Shouzhou

    2016-12-01

    We report here a label-free and sensitive electrochemical method for probing Citrate synthase (CS) activity based on detailed investigations into the nucleic acid-mimicking coordination polymer (CP) formed from the coenzyme A (CoA)-Ag(I) repeat units. Our biosensing approach provides an especial and significant detection mechanism: CS can catalyze the essential condensation reaction between acetyl-coenzyme A (Ac-CoA) and oxaloacetate (OAA) to form citrate and CoA; then, in the presence of Ag(I), CoA-Ag(I) CP can be in situ formed because of the strong complexation ability of thiol groups of CoA toward Ag(I). The generated CoA-Ag(I) CP attaches to graphene-modified glassy carbon electrode surface by multiple adenine bases deriving from CoA and acting as the side groups along the polymeric backbone, which displays efficient H 2 O 2 -electrocatalyzing activity. More importantly, by using the formed polymer as signal output, the process is implemented to quantitatively analyze the activity of CS. Under the optimal conditions, CS with a detection limit as low as 0.00165U/µL could be sensitively probed with a wide linear range from 0.0033 to 0.264U/µL. Furthermore, with the character of label-free detection, high sensitivity and excellent selectivity, this strategy offers a convenient and specific method for CS activity detection and relevant inhibitors screening, which holds a promising potential in the practical application of CS-based biochemical research, disease diagnosis and drug discovery. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. The long non-coding RNA TP73-AS1 modulates HCC cell proliferation through miR-200a-dependent HMGB1/RAGE regulation.

    Science.gov (United States)

    Li, Shaling; Huang, Yan; Huang, Yun; Fu, Yongming; Tang, Daolin; Kang, Rui; Zhou, Rongrong; Fan, Xue-Gong

    2017-04-12

    P73 antisense RNA 1 T (non-protein coding), also known as TP73-AS1, is a long non-coding RNA (lncRNA) which is involved in cell proliferation and the development of tumors. However, the exact effects and molecular mechanisms of TP73-AS1 in hepatocellular carcinoma (HCC) progression are still unknown. The present study is aimed to investigate the detailed functions and the mechanism of TP73-AS1 in regulation of HCC cell proliferation. TP73-AS1 expression in HCC tissues and cell lines was determined using real-time PCR assays; the correlation of TP73-AS1 expression with clinicopathological features of HCC was analyzed. The functions of TP73-AS1 in regulation of HCC cell proliferation was evaluated using MTT and BrdU assays. The candidate upstream miRNAs of HMGB1 were screened using miRcode, miRWalk, miRanda and Target scan, verified using real-time PCR assays. The interaction between TP73-AS1 and miR-200a was confirmed using Luciferase report gene assays. The proten levels of HMGB1 signaling-related factors in response to co-processing TP73-AS1 knockdown and miR-200a inhibition were determined using Western blot assays and ELISA. Further, miR-200a, HMGB1 mRNA and RAGE mRNA and their correlations in HCC tissues were determined. TP73-AS1 was upregulated in HCC tissues and cell lines. High TP73-AS1 expression was correlated with worse clinicopathological features, poorer prognosis and shorter survival. Knockdown of TP73-AS1 inhibited the HCC proliferation and the expression levels of HMGB1, RAGE and NF-κB in HCC cells. By using online tools, we screened out several candidate upstream miRNAs of HMGB1, among which miR-200a overexpression inhibited HMGB1 mRNA expression the most significantly. By using luciferase assays, we confirmed that miR-200a could directly bind to TP73-AS1 and the 3'UTR of HMGB1; TP73-AS1 competed with HMGB1 for miR-200a binding. MiR-200a inhibition could up-regulate HMGB1, RAGE, NF-κB expression as well as NF-κB regulated cytokines levels, which could be partially restored by si-TP73-AS1. In HCC tissues, miR-200a was down-regulated while HMGB1 and RAGE were up-regulated; TP73-AS1 was inversely correlated with miR-200a, while positively correlated with HMGB1 and RAGE, respectively. Our data indicated that TP73-AS1 might be an oncogenic lncRNA that promoted proliferation of HCC and could be regarded as a therapeutic target in human HCC.

  19. No evidence for a dependence of the mass-size relation of early-type galaxies on environment in the local universe

    Energy Technology Data Exchange (ETDEWEB)

    Huertas-Company, M.; Shankar, F.; Mei, S. [GEPI, Paris Observatory, 77 Avenue, Denfert-Rochereau 75014, Paris (France); Bernardi, M.; Meert, A.; Vikram, V. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Aguerri, J. A. L. [Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife (Spain)

    2013-12-10

    The early-type galaxy (ETG) mass-size relation has largely been studied to understand how these galaxies assembled their mass. One key observational result of the last years is that massive galaxies increased their size by a factor of a few at fixed stellar mass from z ∼ 2. Hierarchical models favor minor mergers as a plausible driver of this size growth. Some of these models predict a significant environmental dependence in the sense that galaxies residing in more massive halos tend to be larger than galaxies in lower mass halos, at fixed stellar mass and redshift. At present, observational results of this environmental dependence are contradictory. In this paper we revisit this issue in the local universe, by investigating how the sizes of massive ETGs depend on a large-scale environment using an updated and accurate sample of ETGs in different environments—field, group, and clusters—from the Sloan Digital Sky Survey DR7. Our analysis does not show any significant environmental dependence of the sizes of central and satellite ETGs at fixed stellar mass at z ∼ 0. The size-mass relation of early-type galaxies at z ∼ 0 seems to be universal, i.e., independent of the mass of the host halo and of the position of the galaxy in that halo (central or satellite). The result is robust to different galaxy selections based on star formation, morphology, or central density. Considering our observational errors and the size of the sample, any size ratio larger than 30%-40% between massive galaxies (log(M {sub *}/M {sub ☉}) > 11) living in clusters and in the field can be ruled out at 3σ level.

  20. A dependence of a sports result on physical development, morphofunctional and special strength preparedness data of weightlifters at the stage of preliminary basic training

    Directory of Open Access Journals (Sweden)

    Oleksandr Piven

    2017-07-01

    Full Text Available Purpose: establishing the nature of the relationship between the sporting result of weightlifters 15–17 years and the level of their special physical and morphofunctional preparedness at the stage of preliminary basic training. Material & Methods: 30 athletes of the group of preliminary basic training of the second year of training were involved in the experiment. The study was conducted on the basis of the department of weightlifting and boxing of the Kharkov State Academy of Physical Culture and Children's Sports School "KhTP". Result: correlation between the parameters of the morphofunctional, speed-power and special (competitive readiness of weightlifters of preliminary basic training are identified. The conducted research shows that the result of competitive exercises of athletes specializing in weightlifting, at the stage of preliminary basic training depends on the strength and speed-strength preparedness. Conclusion: it is established that the correlation between the results of competitive exercises and standing high jump, standing long jump, running at 30 m may indicate a correlation between the strength and speed-strength preparedness of athletes specializing in weightlifting at the stage of preliminary basic training.

  1. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  2. Characterization of the gacA-dependent surface and coral mucus colonization by an opportunistic coral pathogen Serratia marcescens PDL100.

    Science.gov (United States)

    Krediet, Cory J; Carpinone, Emily M; Ritchie, Kim B; Teplitski, Max

    2013-05-01

    Opportunistic pathogens rely on global regulatory systems to assess the environment and to control virulence and metabolism to overcome host defenses and outcompete host-associated microbiota. In Gammaproteobacteria, GacS/GacA is one such regulatory system. GacA orthologs direct the expression of the csr (rsm) small regulatory RNAs, which through their interaction with the RNA-binding protein CsrA (RsmA), control genes with functions in carbon metabolism, motility, biofilm formation, and virulence. The csrB gene was controlled by gacA in Serratia marcescens PDL100. A disruption of the S. marcescens gacA gene resulted in an increased fitness of the mutant on mucus of the host coral Acropora palmata and its high molecular weight fraction, whereas the mutant was as competitive as the wild type on the low molecular weight fraction of the mucus. Swarming motility and biofilm formation were reduced in the gacA mutant. This indicates a critical role for gacA in the efficient utilization of specific components of coral mucus and establishment within the surface mucopolysaccharide layer. While significantly affecting early colonization behaviors (coral mucus utilization, swarming motility, and biofilm formation), gacA was not required for virulence of S. marcescens PDL100 in either a model polyp Aiptasia pallida or in brine shrimp Artemia nauplii. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Antimicrobial medium- and long-chain free fatty acids prevent PrfA-dependent activation of virulence genes in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Sternkopf Lillebæk, Eva Maria; Lambert Nielsen, Stine; Scheel Thomasen, Rikke

    2017-01-01

    in the intestinal environment. In the gastrointestinal phase of infection, the bacterium encounters a variety of antimicrobial agents, including medium- and long-chain free fatty acids that are commonly found in our diet and as active components of bile. Here we show that subinhibitory concentrations of specific...... antimicrobial free fatty acids act to downregulate transcription of PrfA-activated virulence genes. Interestingly, the inhibitory effect is also evident in cells encoding a constitutively active variant of PrfA. Collectively, our data suggest that antimicrobial medium- and long-chain free fatty acids may act...... as signals to prevent PrfA-mediated activation of virulence genes in environments where PrfA activation is not required, such as in food and the gastrointestinal tract....

  4. Can weighting compensate for nonresponse bias in a dependent variable? An evaluation of weighting methods to correct for substantive bias in a mail survey among Dutch municipalities

    NARCIS (Netherlands)

    van Goor, H; Stuiver, B

    1998-01-01

    Due to a lack of pertinent data, little is known about nonresponse in substantive, generally "dependent" variables and its consequences. However, in a study on policy performance of Dutch municipalities, we were fortunately able to gather performance data fur respondents and nonrespondents from

  5. Male Sterile2 Encodes a Plastid-Localized Fatty Acyl Carrier Protein Reductase Required for Pollen Exine Development in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.; Shanklin, J.; Yu, X.-H.; Zhang, K.; Shi, J.; De Oliveira, S.; Schreiber, L.; Zhang, D.

    2011-10-01

    Male Sterile2 (MS2) is predicted to encode a fatty acid reductase required for pollen wall development in Arabidopsis (Arabidopsis thaliana). Transient expression of MS2 in tobacco (Nicotiana benthamiana) leaves resulted in the accumulation of significant levels of C16 and C18 fatty alcohols. Expression of MS2 fused with green fluorescent protein revealed that an amino-terminal transit peptide targets the MS2 to plastids. The plastidial localization of MS2 is biologically important because genetic complementation of MS2 in ms2 homozygous plants was dependent on the presence of its amino-terminal transit peptide or that of the Rubisco small subunit protein amino-terminal transit peptide. In addition, two domains, NAD(P)H-binding domain and sterile domain, conserved in MS2 and its homologs were also shown to be essential for MS2 function in pollen exine development by genetic complementation testing. Direct biochemical analysis revealed that purified recombinant MS2 enzyme is able to convert palmitoyl-Acyl Carrier Protein to the corresponding C16:0 alcohol with NAD(P)H as the preferred electron donor. Using optimized reaction conditions (i.e. at pH 6.0 and 30 C), MS2 exhibits a K{sub m} for 16:0-Acyl Carrier Protein of 23.3 {+-} 4.0 {mu}m, a V{sub max} of 38.3 {+-} 4.5 nmol mg{sup -1} min{sup -1}, and a catalytic efficiency/K{sub m} of 1,873 m{sup -1} s{sup -1}. Based on the high homology of MS2 to other characterized fatty acid reductases, it was surprising that MS2 showed no activity against palmitoyl- or other acyl-coenzyme A; however, this is consistent with its plastidial localization. In summary, genetic and biochemical evidence demonstrate an MS2-mediated conserved plastidial pathway for the production of fatty alcohols that are essential for pollen wall biosynthesis in Arabidopsis.

  6. Mechanisms of toxicity of di(2-ethylhexyl) phthalate on the reproductive health of male zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Uren-Webster, Tamsyn M.; Lewis, Ceri; Filby, Amy L.; Paull, Gregory C. [Hatherly Laboratories, School of Biosciences, University of Exeter, Prince of Wales Road, Exeter, Devon EX4 4PS (United Kingdom); Santos, Eduarda M., E-mail: e.santos@exeter.ac.uk [Hatherly Laboratories, School of Biosciences, University of Exeter, Prince of Wales Road, Exeter, Devon EX4 4PS (United Kingdom)

    2010-09-01

    Phthalates are ubiquitous in the aquatic environment and are known to adversely affect male reproductive health in mammals through interactions with multiple receptor systems. However, little is known about the risks they pose to fish. This project investigated the effects of di(2-ethylhexyl) phthalate (DEHP), the most commonly used phthalate, on the reproductive health of male zebrafish (Danio rerio). Males were treated with 0.5, 50 and 5000 mg DEHP kg{sup -1} (body weight) for a period of 10 days via intraperitoneal injection. The effects of the exposure were assessed by analysing fertilisation success, testis histology, sperm DNA integrity and transcript profiles of the liver and testis. A significant increase in the hepatosomatic index and levels of hepatic vitellogenin transcript were observed following exposure to 5000 mg DEHP kg{sup -1}. Exposure to 5000 mg DEHP kg{sup -1} also resulted in a reduction in fertilisation success of oocytes spawned by untreated females. However, survival and development of the resulting embryos were unaffected by all treatments, and no evidence of DEHP-induced sperm DNA damage was observed. Exposure to 50 and 5000 mg DEHP kg{sup -1} caused alterations in the proportion of germ cells at specific stages of spermatogenesis in the testis, including a reduction in the proportion of spermatozoa and an increase in the proportion of spermatocytes, suggesting that DEHP may inhibit the progression of meiosis. In parallel, exposure to 5000 mg DEHP kg{sup -1} increased the levels of two peroxisome proliferator-activated receptor (PPAR) responsive genes (acyl-coenzyme A oxidase 1 (acox1) and enoyl-coenzyme A, hydratase/3-hydroxyacyl coenzyme A dehydrogenase (ehhadh). These data demonstrated that exposure to high concentrations of DEHP disrupts spermatogenesis in adult zebrafish with a consequent decrease in their ability to fertilise oocytes spawned by untreated females. Furthermore, our data suggest that the adverse effects caused by

  7. Rosa Mosqueta Oil Prevents Oxidative Stress and Inflammation through the Upregulation of PPAR-α and NRF2 in C57BL/6J Mice Fed a High-Fat Diet.

    Science.gov (United States)

    González-Mañán, Daniel; D'Espessailles, Amanda; Dossi, Camila G; San Martín, Marcela; Mancilla, Rodrigo A; Tapia, Gladys S

    2017-04-01

    Background: Rosa mosqueta (RM) oil is characterized by high concentrations of antioxidants and α-linolenic acid (ALA; 18:3n-3). We have previously demonstrated in male C57BL/6J mice that RM decreases hepatic steatosis, a condition strongly associated with oxidative stress and inflammation. Objective: We studied the molecular mechanisms that underlie the role of RM in preventing high-fat diet (HFD)-induced oxidative stress and inflammation. Methods: Male C57BL/6J mice aged 28 d and weighing 12-14 g were divided into the following groups and fed for 12 wk: control diet (CD; 10% fat, 20% protein, and 70% carbohydrates); CD + RM (1.94 mg ALA ⋅ g body weight -1 ⋅ d -1 administered by oral gavage); HFD (60% fat, 20% protein, and 20% carbohydrates); and HFD + RM. General parameters (body weight, visceral fat, and histology); glucose metabolism [homeostasis model assessment and blood glucose area under the curve (AUC)]; oxidative stress [hepatic nuclear factor (erythroid-derived 2)-like-2 (NRF2) and heme oxygenase 1 (HO-1) concentrations]; and inflammation [hepatic peroxisome proliferator-activated receptor α (PPAR-α) and acyl-coenzyme A oxidase 1 (ACOX1) concentrations, blood tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) concentrations, and Tnfa and Il1b mRNA expression in liver and visceral adipose tissue] were evaluated. Results: In the HFD + RM mice, the final body weight (24.8 ± 1.1 g) was 19% lower than in the HFD mice (30.6 ± 2.8 g) ( P < 0.05). Visceral fat was 34% lower in the HFD + RM mice than in the HFD mice ( P < 0.05). The blood glucose AUC was 29% lower and Tnfa and Il1b expression levels were 47% and 59% lower, respectively, in the HFD + RM mice than in the HFD mice ( P < 0.05). HFD + RM mice had 40% less hepatic steatosis ( P < 0.05) and lower upregulation of PPAR-α (33%), ACOX1 (50%), NRF2 (39%), and HO-1 (68%) protein concentrations than did the HFD mice ( P < 0.05). Conclusions: Our findings suggest that RM supplementation

  8. Peroxisome proliferator-activated receptors, estrogenic responses and biotransformation system in the liver of salmon exposed to tributyltin and second messenger activator

    International Nuclear Information System (INIS)

    Pavlikova, Nela; Kortner, Trond M.; Arukwe, Augustine

    2010-01-01

    The mechanisms by which organotin compounds produce modulations of the endocrine systems and other biological responses are not fully understood. In this study, juvenile salmon were force-fed diet containing TBT (0: solvent control, 0.1, 1 and 10 mg/kg fish) for 72 h. Subsequently, fish exposed to solvent control and 10 mg TBT were exposed to waterborne concentration (200 μg/l) of the adenylate cyclase (AC) stimulator, forskolin for 2 and 4 h. The overall aim of the study was to explore whether TBT endocrine disruptive effects involve second messenger activation. Liver was sampled from individual fish (n = 8) at the end of the exposures. The transcription patterns of peroxisome proliferator-activated receptor (PPAR) isotype and acyl-coenzyme A oxidase 1 (ACOX1), aromatase isoform, estrogen receptor-α (ERα), pregnane X receptor (PXR), CYP3A and glutathione S-transferase (GST) genes were measured by quantitative polymerase chain reaction (qPCR). Our data showed a consistent increase in PPARα, PPARβ and PPARγ mRNA and protein expression after TBT exposure that were inversely correlated with ACOX1 mRNA levels. Forskolin produced PPAR isotype-specific mRNA and protein effects that were modulated by TBT. ACOX1 expression was decreased (at 2 h) and increased (at 4 h) by forskolin and the presence of TBT potentiated these effects. TBT apparently increased mRNA and protein levels of cyp19a, compared to the solvent control, whereas cyp19b mRNA levels were unaffected by TBT treatment. Combined TBT and forskolin exposure produced respective decrease and increase of mRNA levels of cyp19a and cyp19b, compared with control. TBT decreased ERα mRNA at low dose (1 mg/kg) and forskolin exposure alone produced a consistent decrease of ERα mRNA levels that were not affected by the presence of TBT. Interestingly, PXR and CYP3A mRNA levels were differentially affected, either decreased or increased, after exposure to TBT and forskolin, singly and also in combination. GST mRNA was

  9. Homozygous and heterozygous GH transgenesis alters fatty acid composition and content in the liver of Amago salmon (Oncorhynchus masou ishikawae

    Directory of Open Access Journals (Sweden)

    Manabu Sugiyama

    2012-08-01

    Growth hormone (GH transgenic Amago (Oncorhynchus masou ishikawae, containing the sockeye GH1 gene fused with metallothionein-B promoter from the same species, were generated and the physiological condition through lipid metabolism compared among homozygous (Tg/Tg and heterozygous GH transgenic (Tg/+ Amago and the wild type control (+/+. Previously, we have reported that the adipose tissue was generally smaller in GH transgenic fish compared to the control, and that the Δ-6 fatty acyl desaturase gene was down-regulated in the Tg/+ fish. However, fatty acid (FA compositions have not been measured previously in these fish. In this study we compared the FAs composition and content in the liver using gas chromatography. Eleven kinds of FA were detected. The composition of saturated and monounsaturated fatty acids (SFA and MUFA such as myristic acid (14:0, palmitoleic acid (16:1n-7, and cis-vaccenic acid (cis-18:1n-7 was significantly (P<0.05 decreased in GH transgenic Amago. On the other hand, the composition of polyunsaturated fatty acids (PUFAs such as linoleic acid (18:2n-6, arachidonic acid (20:4n-6, and docosapentaenoic acid (22:5n-3 was significantly (P<0.05 increased. Levels of serum glucose and triacylglycerol were significantly (P<0.05 decreased in the GH transgenics compared with +/+ fish. Furthermore, 3′-tag digital gene expression profiling was performed using liver tissues from Tg/Tg and +/+ fish, and showed that Mid1 interacting protein 1 (Mid1ip1, which is an important factor to activate Acetyl-CoA carboxylase (ACC, was down-regulated in Tg/Tg fish, while genes involved in FA catabolism were up-regulated, including long-chain-fatty-acid–CoA ligase 1 (ACSL1 and acyl-coenzyme A oxidase 3 (ACOX3. These data suggest that liver tissue from GH transgenic Amago showed starvation by alteration in glucose and lipid metabolism due to GH overexpression. The decrease of serum glucose suppressed Mid1ip1, and caused a decrease of de novo FA synthesis, resulting

  10. mRNA expression of genes regulating lipid metabolism in ringed seals (Pusa hispida) from differently polluted areas

    Energy Technology Data Exchange (ETDEWEB)

    Castelli, Martina Galatea [Norwegian Polar Institute, Fram Centre, 9296 Tromsø (Norway); University of Bergen, Department of Biology, 5020 Bergen (Norway); Rusten, Marte; Goksøyr, Anders [University of Bergen, Department of Biology, 5020 Bergen (Norway); Routti, Heli, E-mail: heli.routti@npolar.no [Norwegian Polar Institute, Fram Centre, 9296 Tromsø (Norway)

    2014-01-15

    Highlights: •Genes regulating lipid metabolism were studied in ringed seals. •We compared highly contaminated Baltic seals and less contaminated Svalbard seals. •mRNA expression of hepatic PPARγ was higher in the Baltic seals. •mRNA expression of adipose PPARγ target genes was higher in the Baltic seals. •Contaminant exposure may affect lipid metabolism in the Baltic ringed seals. -- Abstract: There is a growing concern about the ability of persistent organic pollutants (POPs) to influence lipid metabolism. Although POPs are found at high concentrations in some populations of marine mammals, for example in the ringed seal (Pusa hispida) from the Baltic Sea, little is known about the effects of POPs on their lipid metabolism. An optimal regulation of lipid metabolism is crucial for ringed seals during the fasting/molting season. This is a physiologically stressful period, during which they rely on the energy stored in their fat reserves. The mRNA expression levels for seven genes involved in lipid metabolism were analyzed in liver and/or blubber tissue from molting ringed seals from the polluted Baltic Sea and a less polluted reference location, Svalbard (Norway). mRNA expression of genes encoding peroxisome proliferator-activated receptors (PPAR) α and γ and their target genes acyl-coenzyme A oxidase 1 (ACOX1) and cluster of differentiation 36 (CD36) were analyzed in liver. mRNA expression level of genes encoding PPARβ, PPARγ and their target genes encoding fatty acid binding protein 4 (FABP4) and adiponectin (ADIPOQ) were measured in inner and middle blubber layers. In addition, we evaluated the influence of molting status on hepatic mRNA expression of genes encoding PPARs and their target genes in ringed seals from Svalbard. Our results show higher mRNA expression of genes encoding hepatic PPARγ and adipose PPARβ, FABP4, and ADIPOQ in the Baltic seals compared to the Svalbard seals. A positive relationship between mRNA expressions of genes

  11. In HepG2 cells, coexisting carnitine deficiency masks important indicators of marginal biotin deficiency.

    Science.gov (United States)

    Bogusiewicz, Anna; Boysen, Gunnar; Mock, Donald M

    2015-01-01

    A large number of birth defects are related to nutrient deficiencies; concern that biotin deficiency is teratogenic in humans is reasonable. Surprisingly, studies indicate that increased urinary 3-hydroxyisovalerylcarnitine (3HIAc), a previously validated marker of biotin deficiency, is not a valid biomarker in pregnancy. In this study we hypothesized that coexisting carnitine deficiency can prevent the increase in 3HIAc due to biotin deficiency. We used a 2-factor nutrient depletion design to induce isolated and combined biotin and carnitine deficiency in HepG2 cells and then repleted cells with carnitine. To elucidate the metabolic pathogenesis, we quantitated intracellular and extracellular free carnitine, acylcarnitines, and acylcarnitine ratios using liquid chromatography-tandem mass spectrometry. Relative to biotin-sufficient, carnitine-sufficient cells, intracellular acetylcarnitine increased by 90%, propionylcarnitine more than doubled, and 3HIAc increased by >10-fold in biotin-deficient, carnitine-sufficient (BDCS) cells, consistent with a defensive mechanism in which biotin-deficient cells transesterify the acyl-coenzyme A (acyl-CoA) substrates of the biotin-dependent carboxylases to the related acylcarnitines. Likewise, in BDCS cells, the ratio of acetylcarnitine to malonylcarnitine and the ratio of propionylcarnitine to methylmalonylcarnitine both more than tripled, and the ratio of 3HIAc to 3-methylglutarylcarnitine (MGc) increased by >10-fold. In biotin-deficient, carnitine-deficient (BDCD) cells, the 3 substrate-derived acylcarnitines changed little, but the substrate:product ratios were masked to a lesser extent. Moreover, carnitine repletion unmasked biotin deficiency in BDCD cells as shown by increases in acetylcarnitine, propionylcarnitine, and 3HIAc (each increased by >50-fold). Likewise, ratios of acetylcarnitine:malonylcarnitine, propionylcarnitine:methylmalonylcarnitine, and 3HIAc:MGc all increased by >8-fold. Our findings provide strong

  12. In HepG2 Cells, Coexisting Carnitine Deficiency Masks Important Indicators of Marginal Biotin Deficiency123

    Science.gov (United States)

    Bogusiewicz, Anna; Boysen, Gunnar; Mock, Donald M

    2015-01-01

    Background: A large number of birth defects are related to nutrient deficiencies; concern that biotin deficiency is teratogenic in humans is reasonable. Surprisingly, studies indicate that increased urinary 3-hydroxyisovalerylcarnitine (3HIAc), a previously validated marker of biotin deficiency, is not a valid biomarker in pregnancy. Objective: In this study we hypothesized that coexisting carnitine deficiency can prevent the increase in 3HIAc due to biotin deficiency. Methods: We used a 2-factor nutrient depletion design to induce isolated and combined biotin and carnitine deficiency in HepG2 cells and then repleted cells with carnitine. To elucidate the metabolic pathogenesis, we quantitated intracellular and extracellular free carnitine, acylcarnitines, and acylcarnitine ratios using liquid chromatography–tandem mass spectrometry. Results: Relative to biotin-sufficient, carnitine-sufficient cells, intracellular acetylcarnitine increased by 90%, propionylcarnitine more than doubled, and 3HIAc increased by >10-fold in biotin-deficient, carnitine-sufficient (BDCS) cells, consistent with a defensive mechanism in which biotin-deficient cells transesterify the acyl-coenzyme A (acyl-CoA) substrates of the biotin-dependent carboxylases to the related acylcarnitines. Likewise, in BDCS cells, the ratio of acetylcarnitine to malonylcarnitine and the ratio of propionylcarnitine to methylmalonylcarnitine both more than tripled, and the ratio of 3HIAc to 3-methylglutarylcarnitine (MGc) increased by >10-fold. In biotin-deficient, carnitine-deficient (BDCD) cells, the 3 substrate-derived acylcarnitines changed little, but the substrate:product ratios were masked to a lesser extent. Moreover, carnitine repletion unmasked biotin deficiency in BDCD cells as shown by increases in acetylcarnitine, propionylcarnitine, and 3HIAc (each increased by >50-fold). Likewise, ratios of acetylcarnitine:malonylcarnitine, propionylcarnitine:methylmalonylcarnitine, and 3HIAc:MGc all increased

  13. L-Carnitine and its Protective Role in Contrast-Induced Renal Injury in Rats

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    Mosaddeg Jabbari

    2012-06-01

    Full Text Available Background & Objectives: Contrast media-induced nephrotoxicity is one of the most common causes of acute renal failure and promotes both increased morbidity and greater healthcare costs. several mechanisms by which contrast media induces renal injury. These include renal vasoconstriction and direct effect of the contrast agents and reactive oxygen metabolites production. L-carnitine facilitates the transfer of long-chain fatty acids into the mitochondria. By this mechanism carnitine maintains low pools of fatty acid (acyl-coenzyme a compounds, which are potentially toxic. However some of the actions of L-carnitine may be opposite to the toxic effects of contrast media. This study examined wheter administration of L-carnitine ameliorates contrast media-induced renal injury in rats.   Methods : Fifty Sprauge-Dawley rats, weighting 140-230 gr were assigned to one of five treatment groups: group A(control rats were given normal saline injections daily for 4 consecutive days, group B rats were given contrast media(diatrizoate meglumine 1cc/kg/d, group C rats were given meglumine 1cc/kg/d and carnitine 200mg/kg/d, group D rats were given meglumine 1cc/kg and carnitine 80mg/kg/d, and group E rats were given carnitine 200mg/kg/d. Four days after injections, the rat were killed and their kidneys and blood samples were prepared for pathological and biochemistry examination. Histological scoring of renal cortical pathology was performed.   Results: In rats that were given meglumine and no carnitine, renal function tend to be lower than in control group (p=0.001. Among rats injected with meglumine, those given 200mg/kg/d of L-carnitine had higher creatinine clearances at day 4 than the rats not given carnitine (p=00.04. Renal cortical histopathology changes were milder with meglumine and L-carnitine, particularly at 200mg/kg/d.   Conclusions: In rats receiving meglumine, daily L- carnitine injections, particularly at 200 mg/kg ameliorates the severity of

  14. Proteome analysis of dormancy-released seeds of Fraxinus mandshurica Rupr. in response to re-dehydration under different conditions.

    Science.gov (United States)

    Zhang, Peng; Liu, Di; Shen, Hailong; Li, Yuhua; Nie, Yuzhe

    2015-03-02

    Desiccation tolerance is the ability of orthodox seeds to achieve equilibrium with atmospheric relative humidity and to survive in this state. Understanding how orthodox seeds respond to dehydration is important for improving quality and long-term storage of seeds under low temperature and drought stress conditions. Long-term storage of seeds is an artificial situation, because in most natural situations a seed that has been shed may not remain in a desiccated state for very long, and if dormant it may undergo repeated cycles of hydration. Different types of seeds are differentially sensitive to desiccation and this directly affects long-term storage. For these reasons, many researchers are investigating loss of desiccation tolerance during orthodox seed development to understand how it is acquired. In this study, the orthodox seed proteome response of Fraxinus mandshurica Rupr. to dehydration (to a relative water content of 10%, which mimics seed dehydration) was investigated under four different conditions viz. 20 °C; 20 °C with silica gel; 1 °C; and 1 °C after pretreatment with Ca2+. Proteins from seeds dehydrated under different conditions were extracted and separated by two-dimensional difference gel electrophoresis (2D-DIGE). A total of 2919 protein spots were detected, and high-resolution 2D-DIGE indicated there were 27 differentially expressed. Seven of these were identified using MALDI TOF/TOF mass spectrometry. Inferences from bioinformatics annotations of these proteins established the possible involvement of detoxifying enzymes, transport proteins, and nucleotide metabolism enzymes in response to dehydration. Of the seven differentially abundant proteins, the amounts of six were down-regulated and one was up-regulated. Also, a putative acyl-coenzyme A oxidase of the glyoxylate cycle increased in abundance. In particular, the presence of kinesin-1, a protein important for regulation and cargo interaction, was up-regulated in seeds exposed to low

  15. mRNA expression of genes regulating lipid metabolism in ringed seals (Pusa hispida) from differently polluted areas

    International Nuclear Information System (INIS)

    Castelli, Martina Galatea; Rusten, Marte; Goksøyr, Anders; Routti, Heli

    2014-01-01

    Highlights: •Genes regulating lipid metabolism were studied in ringed seals. •We compared highly contaminated Baltic seals and less contaminated Svalbard seals. •mRNA expression of hepatic PPARγ was higher in the Baltic seals. •mRNA expression of adipose PPARγ target genes was higher in the Baltic seals. •Contaminant exposure may affect lipid metabolism in the Baltic ringed seals. -- Abstract: There is a growing concern about the ability of persistent organic pollutants (POPs) to influence lipid metabolism. Although POPs are found at high concentrations in some populations of marine mammals, for example in the ringed seal (Pusa hispida) from the Baltic Sea, little is known about the effects of POPs on their lipid metabolism. An optimal regulation of lipid metabolism is crucial for ringed seals during the fasting/molting season. This is a physiologically stressful period, during which they rely on the energy stored in their fat reserves. The mRNA expression levels for seven genes involved in lipid metabolism were analyzed in liver and/or blubber tissue from molting ringed seals from the polluted Baltic Sea and a less polluted reference location, Svalbard (Norway). mRNA expression of genes encoding peroxisome proliferator-activated receptors (PPAR) α and γ and their target genes acyl-coenzyme A oxidase 1 (ACOX1) and cluster of differentiation 36 (CD36) were analyzed in liver. mRNA expression level of genes encoding PPARβ, PPARγ and their target genes encoding fatty acid binding protein 4 (FABP4) and adiponectin (ADIPOQ) were measured in inner and middle blubber layers. In addition, we evaluated the influence of molting status on hepatic mRNA expression of genes encoding PPARs and their target genes in ringed seals from Svalbard. Our results show higher mRNA expression of genes encoding hepatic PPARγ and adipose PPARβ, FABP4, and ADIPOQ in the Baltic seals compared to the Svalbard seals. A positive relationship between mRNA expressions of genes

  16. Cell Suspension Culture of Eriobotrya japonica Regulates the Diabetic and Hyperlipidemic Signs of High-Fat-Fed Mice

    Directory of Open Access Journals (Sweden)

    Jin-Bin Wu

    2013-03-01

    Full Text Available The present study investigates the anti-hyperlipidemic and antihyperglycemic effects and mechanism in high-fat (HF-fed mice of cell suspension culture of Eriobotrya japonica (TA, which contains a great number of pentacyclic terpenoids. Firstly, C57BL/6J mice were randomly divided into two groups: the control (CON group was fed with a low-fat diet (n = 9, whereas the experimental group was fed a 45% HF diet for 8 weeks. Afterwards, the CON group was treated with vehicle, whereas the HF group was subdivided into five groups and was orally given TA or rosiglitazone or not for 4 weeks. Blood and visceral adipose tissue, liver tissue and skeletal muscle were examined. Treatment with TA reduced body weight gain, weights of white adipose tissue (WAT (including epididymal, perirenal, mesenteric WAT and visceral fat, and hepatic triacylglycerol content significantly without affecting food intake in diet-induced diabetic mice. TA effectively prevented HF diet-induced increases in the levels of blood glucose, insulin, leptin and HOMA-IR index (p < 0.001, p < 0.05, p < 0.05, p < 0.01, respectively and attenuated insulin resistance. Treatment with TA, adipocytes in the visceral depots showed a reduction in size. TA effectively significantly increased the protein contents of phosphorylation of AMPK-α (Thr172 both in liver and adipose tissue. It is shown that TA exhibits hypolipidemic effect in HF-fed mice by decreasing gene expressions of fatty acid synthesis, including acyl-coenzyme A: diacylglycerol acyltransferase (DGAT 2, which catalyzes the final step in the synthesis of triglycerides, and antidiabetic properties occurred as a result of decreased hepatic glucose production via phosphenolpyruvate carboxykinase (PEPCK down- regulation, improved insulin sensitization and TA (at 1.0 g/kg dose decreased expression of hepatic and adipose 11-β-hydroxysteroid dehydroxygenase (11β-HSD1 gene, which contributed in attenuating diabetic state. Futhermore, TA at

  17. MRNA expression of genes regulating lipid metabolism in ringed seals (Pusa hispida) from differently polluted areas.

    Science.gov (United States)

    Castelli, Martina Galatea; Rusten, Marte; Goksøyr, Anders; Routti, Heli

    2014-01-01

    There is a growing concern about the ability of persistent organic pollutants (POPs) to influence lipid metabolism. Although POPs are found at high concentrations in some populations of marine mammals, for example in the ringed seal (Pusa hispida) from the Baltic Sea, little is known about the effects of POPs on their lipid metabolism. An optimal regulation of lipid metabolism is crucial for ringed seals during the fasting/molting season. This is a physiologically stressful period, during which they rely on the energy stored in their fat reserves. The mRNA expression levels for seven genes involved in lipid metabolism were analyzed in liver and/or blubber tissue from molting ringed seals from the polluted Baltic Sea and a less polluted reference location, Svalbard (Norway). mRNA expression of genes encoding peroxisome proliferator-activated receptors (PPAR) α and γ and their target genes acyl-coenzyme A oxidase 1 (ACOX1) and cluster of differentiation 36 (CD36) were analyzed in liver. mRNA expression level of genes encoding PPARβ, PPARγ and their target genes encoding fatty acid binding protein 4 (FABP4) and adiponectin (ADIPOQ) were measured in inner and middle blubber layers. In addition, we evaluated the influence of molting status on hepatic mRNA expression of genes encoding PPARs and their target genes in ringed seals from Svalbard. Our results show higher mRNA expression of genes encoding hepatic PPARγ and adipose PPARβ, FABP4, and ADIPOQ in the Baltic seals compared to the Svalbard seals. A positive relationship between mRNA expressions of genes encoding hepatic PPARγ, adipose FABP4, adipose ADIPOQ and ΣPOP concentrations was observed. These findings suggest that lipid metabolism may be affected by contaminant exposure in the Baltic population. mRNA expression of genes encoding PPARβ, PPARγ, FABP4 and ADIPOQ were similar between the mid and inner adipose layer. Hepatic mRNA expression of genes encoding PPARα and PPARγ was higher in the pre

  18. Lipoprotein(a-Associated Molecules Are Prominent Components in Plasma and Valve Leaflets in Calcific Aortic Valve Stenosis

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    Michael Torzewski, MD

    2017-06-01

    Full Text Available Summary: The LPA gene is the only monogenetic risk factor for calcific aortic valve stenosis (CAVS. Oxidized phospholipids (OxPL and lysophosphatidic acid generated by autotaxin (ATX from OxPL are pro-inflammatory. Aortic valve leaflets categorized pathologically from both ATX–apolipoprotein B and ATX–apolipoprotein(a were measureable in plasma. Lipoprotein(a (Lp[a], ATX, OxPL, and malondialdehyde epitopes progressively increased in immunostaining (p < 0.001 for all. Six species of OxPL and lysophosphatidic acid were identified after extraction from valve leaflets. The presence of a constellation of pathologically linked, Lp(a-associated molecules in plasma and in aortic valve leaflets of patients with CAVS suggest that Lp(a is a key etiologic factor in CAVS. Key Words: aortic valve stenosis, autotaxin, inflammation, Lp(a, oxidation-specific epitopes

  19. Autotaxin: Its Role in Biology of Melanoma Cells and as a Pharmacological Target

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    Maciej Jankowski

    2011-01-01

    Full Text Available Autotaxin (ATX is an extracellular lysophospholipase D (lysoPLD released from normal cells and cancer cells. Activity of ATX is detected in various biological fluids. The lysophosphatidic acid (LPA is the main product of ATX. LPA acting through specific G protein-coupled receptors (LPA1-LPA6 affects immunological response, normal development, and malignant tumors' formation and progression. In this review, the impact of autotoxin on biology of melanoma cells and potential treatment is discussed.

  20. Autotaxin Expression Is Regulated at the Post-transcriptional Level by the RNA-binding Proteins HuR and AUF1*

    OpenAIRE

    Sun, Shuhong; Zhang, Xiaotian; Lyu, Lin; Li, Xixi; Yao, Siliang; Zhang, Junjie

    2016-01-01

    Autotaxin (ATX) is a key enzyme that converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a lysophospholipid mediator that regulates cellular activities through its specific G protein-coupled receptors. The ATX-LPA axis plays an important role in various physiological and pathological processes, especially in inflammation and cancer development. Although the transcriptional regulation of ATX has been widely studied, the post-transcriptional regulation of ATX is largely unk...

  1. A New Enzyme Immunoassay for the Quantitative Determination of Classical Autotaxins (ATX?, ATX?, and ATX?) and Novel Autotaxins (ATX? and ATX?)

    OpenAIRE

    Tokuhara, Yasunori; Kurano, Makoto; Shimamoto, Satoshi; Igarashi, Koji; Nojiri, Takahiro; Kobayashi, Tamaki; Masuda, Akiko; Ikeda, Hitoshi; Nagamatsu, Takeshi; Fujii, Tomoyuki; Aoki, Junken; Yatomi, Yutaka

    2015-01-01

    Background Autotaxin (ATX) is a secreted enzyme that converts lysophosphatidylcholine to lysophosphatidic acid, a potent bioactive lipid mediator, through its lysophospholipase D activity. Although five alternative splicing isoforms of ATX have been identified as ATX?, ATX?, ATX?, ATX?, and ATX? and the expression patterns of each isoform differ among several tissues, the clinical significance of each isoform remains to be elucidated. Methods Anti-ATX? and anti-ATX? monoclonal antibodies were...

  2. Genetic and Functional Evidence Supports LPAR1 as a Susceptibility Gene for Hypertension.

    Science.gov (United States)

    Xu, Ke; Ma, Lu; Li, Yang; Wang, Fang; Zheng, Gu-Yan; Sun, Zhijun; Jiang, Feng; Chen, Yundai; Liu, Huirong; Dang, Aimin; Chen, Xi; Chun, Jerold; Tian, Xiao-Li

    2015-09-01

    Essential hypertension is a complex disease affected by genetic and environmental factors and serves as a major risk factor for cardiovascular diseases. Serum lysophosphatidic acid correlates with an elevated blood pressure in rats, and lysophosphatidic acid interacts with 6 subtypes of receptors. In this study, we assessed the genetic association of lysophosphatidic acid receptors with essential hypertension by genotyping 28 single-nucleotide polymorphisms from genes encoding for lysophosphatidic acid receptors, LPAR1, LPAR2, LPAR3, LPAR4, LPAR5, and LPAR6 and their flanking sequences, in 3 Han Chinese cohorts consisting of 2630 patients and 3171 controls in total. We identified a single-nucleotide polymorphism, rs531003 in the 3'-flanking genomic region of LPAR1, associated with hypertension (the Bonferroni corrected P=1.09×10(-5), odds ratio [95% confidence interval]=1.23 [1.13-1.33]). The risk allele C of rs531003 is associated with the increased expression of LPAR1 and the susceptibility of hypertension, particularly in those with a shortage of sleep (P=4.73×10(-5), odds ratio [95% confidence interval]=1.75 [1.34-2.28]). We further demonstrated that blood pressure elevation caused by sleep deprivation and phenylephrine-induced vasoconstriction was both diminished in LPAR1-deficient mice. Together, we show that LPAR1 is a novel susceptibility gene for human essential hypertension and that stress, such as shortage of sleep, increases the susceptibility of patients with risk allele to essential hypertension. © 2015 American Heart Association, Inc.

  3. Cessação tabágica em doentes com neoplasia do pulmão tratados para a dependência nicotínica.

    Directory of Open Access Journals (Sweden)

    L.S. Cox

    2003-01-01

    Full Text Available RESUMO: A manutenção dos hábitos tabágicos em doentes com neoplasia do pulmão está associada a uma menor sobrevivência, desenvolvimento de um segundo tumor primitivo e um maior risco de desencadear ou exacerbar outras patologias, como sejam a DPOC, doença vascular periférica, cardiopatia isquémica e úlcera péptica.Também as formas major de tratamento oncológico (quimioterapia, radioterapia produzem um maior número de complicações e morbilidade entre os doentes fumadores. Apesar disso, pouca atenção tem sido dada à cessação tabágica nos doentes neoplásicos.O objectivo do presente estudo foi avaliar a taxa de abstinência tabágica ao fim de 6 meses em indivíduos com tumor do pulmão submetidos a tratamento da dependência nicotínica e comparar os resultados obtidos com os observados num grupo controlo.Foram englobados 402 fumadores seguidos no Mayo Clinic Nicotine Dependence Center (NDC entre Abril de 1988 e Março de 2000, dos quais 201 apresentavam a neoplasia mencionada. O grupo controlo podia incluir indivíduos com tumores de outros órgãos ou sistemas, bem como outras patologias relacionadas com o tabaco. Todos tinham fumado (cigarros, cachimbo, charutos nos 6 meses que antecederam a terapêutica em causa.A intervenção NDC envolveu uma equipa especializada na dependência nicotínica e compunha-se de múltiplas vertentes: comportamental, psicológica, aditiva, farmacológica e preventiva (nomeadamente das recidivas. As sessões tinham uma duração de 45 a 60 minutos segundo um plano individual, tendo em atenção as necessidades específicas, estadio de mudança e nível de dependência nicotínica. Usualmente, envolvia estratégias comportamentais para controlo de sintomas de abstinência e situações de alto risco. A terapêutica farmacológica foi utilizada frequentemente na ausência de contra-indicações. O follow-up efectuou se ao 1.º, 3.º e 6.º meses.Inicialmente, o doente respondia a um questionário extenso e completo sobre dados demográficos e hábitos tabágicos que incluía o Teste de Dependência Nicotínica de Fagerströn.O grau de motivação e de intenção para deixar de fumar definem o estadio de mudança. Segundo Prochaska e Goldstein existem 5 estadios: Pré-Contemplação — não pensa deixar de fumar nos próximos 6 meses; Contemplação — considera abandonar os hábitos tabágicos nos próximos 6 meses; Preparação — planeia deixar de fumar nos seguintes 30 dias e escolhe a data; Acção — pára de fumar.Foram analisados os dados referentes à neoplasia pulmonar, nomeadamente, estadio, grau, histologia e data do diagnóstico, bem como à existência de outros tumores, DPOC, doença vascular periférica, patologia coronária, diabetes, depressão major, alcoolismo e toxicofilia.A determinação de existência ou não de abandono do tabagismo baseou se nos critérios da Society for Research on Nicotine and Tobacco Subcomunittee on Abstinence Measures. Considerou-se que os indivíduos que não foi possível contactar mantinham os hábitos tabágicos.Globalmente, houve um predomínio da raça branca (97,2% e do sexo masculino (56,7%. Os doentes com tumor do pulmão eram mais velhos (p<0.01 e tinham mantido o tabagismo por um período de tempo superior (p<0.001, apesar da idade de início ser sobreponível. O 1.º grupo apresentava um maior grau de motivação (p=0.003 e um estadio de mudança mais avançado (p=0.002 sendo, no entanto, o número de tentativas prévias de abandono inferior (p=0.023. Estes doentes possuíam, com maior frequência, outras neoplasias (p<0.001.77% dos indivíduos com tumor do pulmão foram observados nos 3 meses após o diagnóstico inicial, sendo o tipo histológico predominante o tumor de não pequenas células (89%. A maioria (93% eram potencialmente ressecáveis (estadios I, II e III.O grupo com neoplasias encontrava se num estadio de mudança mais evoluído que o grupo controlo. A abstinência foi de 7,7% nos estádios de pré-contemplação e contemplação, 22% no estadio de preparação e 28,1% no estadio de acção. A cessação tabágica foi superior nos indivíduos com o diagnóstico de tumor há menos de 3 meses (27,3% quando comparadas com os doentes com neoplasia do pulmão conhecida entre 3 a 6 meses (0% e há mais de 6 meses (7,0%. De salientar que os doentes portadores de patologia vascular periférica e tumor pulmonar apresentavam uma taxa de abandono mais elevada (36,7% versus 19,9%, p=0.042. Verificou-se, também, uma maior probabilidade de permanecerem em abstinência ao fim de 6 meses.Após o ajuste para a idade, sexo, número de cig/dia (últimos 6 meses e estadio de mudança, não houve evidência de diferença estatisticamente significativa na taxa de cessação tabágica de ambos os grupos. COMENTÁRIO: Cox e colegas evidenciaram a eficácia da intervenção terapêutica na desabituação tabágica de doentes com tumor do pulmão. Um dos méritos do referido estudo é o elevado número de indivíduos avaliados e a caracterização dessa população.No entanto, é de referir que se trata de um grupo previamente seleccionado para o tratamento em causa, o que poderá significar que corresponde a indivíduos com maior dificuldade em abandonar os hábitos tabágicos, elevada motivação ou comorbilidade psiquiátrica importante.Embora diversos elementos da comunidade científica apresentem alguma apreensão na aplicação desta estratégia terapêutica durante uma fase de elevada ansiedade para o doente, é inequívoca a maior eficácia da cessação tabágica nos primeiros 3 meses após ser conhecido o referido diagnóstico. Nestes indivíduos, é possível atingir uma motivação significativa e um estadio de mudança mais avançado.Estes resultados desafiam os responsáveis pela terapêutica oncológica a investir no tratamento de dependência nicotínica dos referidos doentes. Apesar do elevado grau de dependência, da menor motivação no passado e grande carga tabágica (≥40 cig/dia 53% versus 38%, verificou se uma taxa da cessação tabágica sobreponível à do grupo de controlo. Após decorridos 6 meses de intervenção, é fundamental o acompanhamento psicológico para prevenir as recidivas sendo preponderante o papel da família nesta luta. O Lung Cancer Study Group verificou diversos benefícios imediatos entre os indivíduos com tumor de não pequenas células ressecado no passado: melhoria da capacidade respiratória; diminuição da dispneia, tosse e expectoração; aumento do apetite; melhoria do olfacto, paladar e da auto estima.Este estudo não permite, no entanto, analisar o resultado de abstinência nicotínica na resposta à terapêutica oncológica, bem como na morbilidade secundária ou mortalidade. Uma das limitações do estudo em análise consistiu na ausência de confirmação bioquímica da abstinência. Não foram, também, discriminadas as diferentes medidas terapêuticas aplicadas a cada indivíduo.Os resultados prometedoras da trabalho de Cox e colaboradores devem encorajar a inclusão da intervenção na dependência nicotínica na terapêutica dos doentes com neoplasia do pulmão. Palavras chave: Tumor do pulmão, fumador, dependência nicotínica, abstinência tabágica, Key-words: Lung cancer, smoker, nicotine dependence, tobacco abstinence

  4. Tumor suppressor gene p16/INK4A/CDKN2A-dependent regulation into and out of the cell cycle in a spontaneous canine model of breast cancer.

    Science.gov (United States)

    Agarwal, Payal; Sandey, Maninder; DeInnocentes, Patricia; Bird, R Curtis

    2013-06-01

    p16/INK4A/CDKN2A is an important tumor suppressor gene that arrests cell cycle in G1 phase inhibiting binding of CDK4/6 with cyclin D1, leaving the Rb tumor suppressor protein unphosphorylated and E2F bound and inactive. We hypothesized that p16 has a role in exit from cell cycle that becomes defective in cancer cells. Well characterized p16-defective canine mammary cancer cell lines (CMT28, CMT27, and CMT12), derived stably p16-transfected CMT cell clones (CMT27A, CMT27H, CMT28A, and CMT28F), and normal canine fibroblasts (NCF), were used to investigate expression of p16 after serum starvation into quiescence followed by re-feeding to induce cell cycle re-entry. The parental CMT cell lines used lack p16 expression either at the mRNA or protein expression levels, while p27 and other p16-associated proteins, including CDK4, CDK6, cyclin D1, and Rb, were expressed. We have successfully demonstrated cell cycle arrest and relatively synchronous cell cycle re-entry in parental CMT12, CMT28 and NCF cells as well as p16 transfected CMT27A, CMT27H, CMT28A, and CMT28F cells and confirmed this by (3)H-thymidine incorporation and flow cytometric analysis of cell cycle phase distribution. p16-transfected CMT27A and CMT27H cells exited cell cycle post-serum-starvation in contrast to parental CMT27 cells. NCF, CMT27A, and CMT28F cells expressed upregulated levels of p27 and p16 mRNA, post-serum starvation, as cells exited cell cycle and entered quiescence. Because quiescence and differentiation are associated with increased levels of p27, our data demonstrating that p16 was upregulated along with p27 during quiescence, suggests a potential role for p16 in maintaining these non-proliferative states. Copyright © 2012 Wiley Periodicals, Inc.

  5. A dependência pela prática de exercícios físicos e o uso de recursos ergogênicos = Physical exercise dependence and the use of ergogenic resources

    Directory of Open Access Journals (Sweden)

    José Luiz Lopes Vieira

    2010-01-01

    Full Text Available Objetivou-se Investigar a ocorrência de dependência por exercícios físicos quanto às características de praticantes de musculação e ginástica em academias, como uso de recursos ergogênicos, sexo e índice de massa corporal. Participaram do estudo 80 sujeitos (27,12 ± 6,60 anos, praticantes de ginástica e/ou musculação em academias, de ambos os sexos. Utilizou-se a Escala de Dependência por Exercícios Físicos, a listagem do tipo de suplemento alimentar utilizado como recurso ergogênico e o Índice de Massa Corporal – IMC (Kg/cm². A análise estatística foi realizada por meio da correlação de Spearman e o teste de Wilcoxon (p The aim of this study is to investigate the occurrence of physical exercise dependence in regards to the characteristics of participants in weight training and exercises at gyms, such as the use ofergogenic resources, gender and body mass index. Eighty subjects (27.12 ± 6.60 years from both genders took part in the study, all of whom practiced gymnastics and/or weight training in gyms. The study utilized the Exercise Dependence Scale, a check list of the kinds of nutritional supplementation used as ergogenic resources, and the Body Mass Index – BMI (Kg cm-². Statistical analysis was performed using Spearman's correlation and the Wilcoxon test (p < 0.05. The results showed that there was no statistically significant difference between physical exercise dependence in men (5.14 ± 1.28 and women (5.60 ± 1.45. The body mass index did not show statistically significant correlation with the scores of dependency, either. However, dependentmen showed high prevalence of use of ergogenic resources (63.63%, p = 0.01, while for dependent women there were no statistically significant results. The body mass index does not relate to the scores of exercise dependence. However, even with a normal BMI, the use of ergogenic resources presents high prevalence among dependent men. As a result, there is evidence that physical exercise dependence is a risk factor for the development of emotional disturbances related to exercise, such as muscle dysmorphia and overtraining.

  6. The transtheoretical model and substance dependence: theoretical and practical aspects O modelo transteórico e a dependência química: aspectos teóricos e práticos

    Directory of Open Access Journals (Sweden)

    Fabiana Andrioni De Biaze Vilela

    2009-12-01

    Full Text Available OBJECTIVE: This paper aims to present and discuss the Transtheoretical Model and its importance for the treatment of substance abuse disorders. METHOD: A literature review was made based on articles from the last 10 years in substance use with human subjects found in PubMed (Medline and the Scientific Electronic Library Online, as well as on the main books written by the creators of the model. From the initial collection of articles related to the Transtheoretical Model, the University of Rhode Island Assessment and substance abuse, those related to other health conditions were excluded. Although articles related to hospitalization were also excluded, as were those related to the Minnesota Model, treatment proposals were included. RESULTS: Although the TTM has been studied for over 20 years, new concerns regarding the initial idea continue to arise. Such concerns include the cross-sectional design of studies employing the model, as well as the prescriptive versus descriptive point of view. DISCUSSION: The review of the Transtheoretical Model brought intentional behavior change to light, which could broaden the understanding of addictive behaviors. Together with its concepts of processes and stages of change, the Transtheoretical Model provides professionals with the idea that the effectiveness of therapy is dependent upon the capability of the therapist to match the technique to the current motivational stage of the patient in the process of change. This demonstrates the importance of identifying the stage of change of the patient when they present for treatment. Here, we describe the principal elements of the Transtheoretical Model, as well as the instruments currently used to identify the stage of change. Finally, criticisms and limitations of the model are discussed.OBJETIVO: Este artigo tem como objetivos a apresentação e discussão do Modelo Transteórico e sua importância para o tratamento da dependência química. MÉTODO: Foi feita revisão de literatura baseada em artigos dos últimos 10 anos sobre abuso de substâncias com sujeitos humanos encontrados no PubMed (Medline e a Scientific Electronic Library Online, bem como as principais obras dos idealizadores da Teoria. Dos artigos encontrados inicialmente sobre o Modelo, University of Rhode Island Assessment e dependência química, aqueles relacionados a outras condições de saúde foram excluídos. Propostas de tratamento foram consideradas (exceto Modelo Minnesota e internação. RESULTADOS: Novas diretrizes surgem sobre a idéia inicial da teoria, apesar da mesma já ser estudada há mais de 20 anos: estudos transversais empregando o modelo, bem como a avaliação do potencial prescritivo ou descritivo do mesmo. DISCUSSÃO: Esta teoria enfoca a mudança intencional de comportamento, o que ampliou a compreensão dos comportamentos aditivos. O Modelo Transteórico sugere aos profissionais que a efetividade do tratamento depende da capacidade do mesmo de aplicar a técnica adequada à situação motivacional do paciente no processo de mudança. Isto demonstra porque é tão importante identificar o estágio de mudança do paciente quando este ingressa no tratamento. O artigo descreve os principais elementos da teoria bem como os principais instrumentos usados atualmente para identificar os estágios. Por fim, são discutidas as críticas e as limitações do modelo.

  7. Gli2a protein localization reveals a role for Iguana/DZIP1 in primary ciliogenesis and a dependence of Hedgehog signal transduction on primary cilia in the zebrafish

    Directory of Open Access Journals (Sweden)

    van Eeden Freek

    2010-04-01

    Full Text Available Abstract Background In mammalian cells, the integrity of the primary cilium is critical for proper regulation of the Hedgehog (Hh signal transduction pathway. Whether or not this dependence on the primary cilium is a universal feature of vertebrate Hedgehog signalling has remained contentious due, in part, to the apparent divergence of the intracellular transduction pathway between mammals and teleost fish. Results Here, using a functional Gli2-GFP fusion protein, we show that, as in mammals, the Gli2 transcription factor localizes to the primary cilia of cells in the zebrafish embryo and that this localization is modulated by the activity of the Hh pathway. Moreover, we show that the Igu/DZIP1protein, previously implicated in the modulation of Gli activity in zebrafish, also localizes to the primary cilium and is required for its proper formation. Conclusion Our findings demonstrate a conserved role of the primary cilium in mediating Hedgehog signalling activity across the vertebrate phylum and validate the use of the zebrafish as a representative model for the in vivo analysis of vertebrate Hedgehog signalling.

  8. História da enfermagem psiquiátrica e a dependência química no Brasil: atravessando a história para reflexão

    OpenAIRE

    Reinaldo, Amanda Márcia dos Santos; Pillon, Sandra Cristina

    2007-01-01

    A formação do enfermeiro em Enfermagem Psiquiátrica e na área de dependências químicas norteia a discussão desse artigo, tendo em vista a complexidade dos problemas relacionados ao ensino de enfermagem, saúde mental, psiquiatria e álcool e drogas. Trata-se de um artigo de revisão de literatura onde as autoras compilaram fontes primárias e secundárias sobre o tema e, a partir da leitura do material bibliográfico, fizeram análises e reflexões acerca dos atravessamentos históricos que permeiam a...

  9. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons. Progress report, 1 December, 1990--15 February, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  10. Revisiting syntactic development in deaf and hearing children from a dependency approach. Comment on "Dependency distance: a new perspective on syntactic patterns in natural languages" by Haitao Liu et al.

    Science.gov (United States)

    Yan, Jingqi

    2017-07-01

    Linguists are always endeavoring to discover universal rules to explain the language phenomena and interrelations [1]. Through a handful of corpus-based studies and a vast body of supporting evidence from psychological experiments, Liu, Xu and Liang [2] arrive at a conclusion on a general tendency toward dependency distance minimization (DDM) and relate this linguistic universal to the constraints of memory. Dependency distance (DD) is hereby introduced as a linguistic property, with quantitative features of frequency, and profound cognitive grounding as well. However, since the authors do not include language development, in this comment, I would like to discuss some future prospects from this perspective.

  11. ATX-LPA receptor axis in inflammation and cancer.

    Science.gov (United States)

    Liu, Shuying; Murph, Mandi; Panupinthu, Nattapon; Mills, Gordon B

    2009-11-15

    Lysophosphatidic acid (LPA, 1- or 2-acyl-sn-glycerol 3-phosphate) mediates a plethora of physiological and pathological activities via interactions with a series of high affinity G protein-coupled receptors (GPCR). Both LPA receptor family members and autotaxin (ATX/LysoPLD), the primary LPA-producing enzyme, are aberrantly expressed in many human breast cancers and several other cancer lineages. Using transgenic mice expressing either an LPA receptor or ATX, we recently demonstrated that the ATX-LPA receptor axis plays a causal role in breast tumorigenesis and cancer-related inflammation, further validating the ATX-LPA receptor axis as a rich therapeutic target in cancer.

  12. Synthesis and biological evaluation of phosphonate derivatives as autotaxin (ATX) inhibitors.

    Science.gov (United States)

    Cui, Peng; Tomsig, Jose L; McCalmont, William F; Lee, Sangderk; Becker, Christopher J; Lynch, Kevin R; Macdonald, Timothy L

    2007-03-15

    Autotaxin (ATX) is an autocrine motility factor that promotes cancer cell invasion, cell migration, and angiogenesis. ATX, originally discovered as a nucleotide phosphodiesterase, is known now to be responsible for the lysophospholipid-preferring phospholipase D activity in plasma. As such, it catalyzes the production of lysophosphatidic acid (LPA) from lysophophatidylcholine (LPC). ATX is thus an attractive drug target; small molecular inhibitors might be efficacious in slowing the spread of cancers. With this study we have generated a series of beta-keto and beta-hydroxy phosphonate derivatives of LPA, some of which are potent ATX inhibitors.

  13. Synthesis and structure-activity relationships of tyrosine-based inhibitors of autotaxin (ATX).

    Science.gov (United States)

    East, James E; Kennedy, Andrew J; Tomsig, Jose L; De Leon, Alexandra R; Lynch, Kevin R; Macdonald, Timothy L

    2010-12-01

    Autotaxin (ATX) is a secreted soluble enzyme that generates lysophosphatidic acid (LPA) through its lysophospholipase D activity. Because of LPA's role in neoplastic diseases, ATX is an attractive therapeutic target due to its involvement in LPA biosynthesis. Here we describe the SAR of ATX inhibitor, VPC8a202, and apply this SAR knowledge towards developing a high potency inhibitor. We found that electron density in the pyridine region greatly influences activity of our inhibitors at ATX. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. PSI1 is responsible for the stearic acid enrichment that is characteristic of phosphatidylinositol in yeast

    DEFF Research Database (Denmark)

    Le Guédard, Marina; Bessoule, Jean-Jacques; Boyer, Valérie

    2009-01-01

    complete disappearance of stearic (but not of palmitic acid) at the sn-1 position of this phospholipid. Moreover, it was found that, whereas glycerol 3-phosphate, lysophosphatidic acid and 1-acyl lysophosphatidylinositol acyltransferase activities were similar in microsomal membranes isolated from wild......-acyl-1-lysolysophosphatidylinositol acyltransferase activity was recovered, and was accompanied by a strong increase in the stearic acid content of lysophosphatidylinositol. As previously suggested for phosphatidylinositol from animal cells (which contains almost exclusively stearic acid...... as the saturated fatty acid), the results obtained in the present study demonstrate that the existence of phosphatidylinositol species containing stearic acid in yeast results from a remodeling of neo-synthesized molecules of phosphatidylinositol....

  15. Differential phospholipid-labeling suggests two subtypes of phospholipase D in rat Leydig cells

    DEFF Research Database (Denmark)

    Lauritzen, L.; Hansen, Harald S.

    1995-01-01

    Cho). The [H] phosphatidylethanol formation in response to 4ß-phorbol 12-myristate 13-acetate (PMA), sphingosine, or Ca-ionophore A23187, was lower when Leydig cells were labeled with 1-O-[H]alkyl lysoPtdCho compared with the responses when [H]myristic acid was employed. In contrast, the results...... for the receptor agonists (vasopressin, bradykinin, and lysophosphatidic acid), using the two labels, showed mole consistency. Thus, the PLD-activity induced by PMA, sphingosine, or A23187 has a more selective substrate range (i.e. mainly acyl-linked PtdCho) than the PLD-activity stimulated via a receptor. Our...

  16. Peroxisome proliferator-activated receptors, estrogenic responses and biotransformation system in the liver of salmon exposed to tributyltin and second messenger activator

    Energy Technology Data Exchange (ETDEWEB)

    Pavlikova, Nela [Department of Biology, Norwegian University of Science and Technology (NTNU), Hogskoleringen 5, 7491 Trondheim (Norway); RECETOX Research Centre for Environmental Chemistry and Ecotoxicology, Masaryk University, Kamenice 3, CZ62500 Brno (Czech Republic); Kortner, Trond M. [Department of Biology, Norwegian University of Science and Technology (NTNU), Hogskoleringen 5, 7491 Trondheim (Norway); Arukwe, Augustine, E-mail: arukwe@bio.ntnu.no [Department of Biology, Norwegian University of Science and Technology (NTNU), Hogskoleringen 5, 7491 Trondheim (Norway)

    2010-08-15

    The mechanisms by which organotin compounds produce modulations of the endocrine systems and other biological responses are not fully understood. In this study, juvenile salmon were force-fed diet containing TBT (0: solvent control, 0.1, 1 and 10 mg/kg fish) for 72 h. Subsequently, fish exposed to solvent control and 10 mg TBT were exposed to waterborne concentration (200 {mu}g/l) of the adenylate cyclase (AC) stimulator, forskolin for 2 and 4 h. The overall aim of the study was to explore whether TBT endocrine disruptive effects involve second messenger activation. Liver was sampled from individual fish (n = 8) at the end of the exposures. The transcription patterns of peroxisome proliferator-activated receptor (PPAR) isotype and acyl-coenzyme A oxidase 1 (ACOX1), aromatase isoform, estrogen receptor-{alpha} (ER{alpha}), pregnane X receptor (PXR), CYP3A and glutathione S-transferase (GST) genes were measured by quantitative polymerase chain reaction (qPCR). Our data showed a consistent increase in PPAR{alpha}, PPAR{beta} and PPAR{gamma} mRNA and protein expression after TBT exposure that were inversely correlated with ACOX1 mRNA levels. Forskolin produced PPAR isotype-specific mRNA and protein effects that were modulated by TBT. ACOX1 expression was decreased (at 2 h) and increased (at 4 h) by forskolin and the presence of TBT potentiated these effects. TBT apparently increased mRNA and protein levels of cyp19a, compared to the solvent control, whereas cyp19b mRNA levels were unaffected by TBT treatment. Combined TBT and forskolin exposure produced respective decrease and increase of mRNA levels of cyp19a and cyp19b, compared with control. TBT decreased ER{alpha} mRNA at low dose (1 mg/kg) and forskolin exposure alone produced a consistent decrease of ER{alpha} mRNA levels that were not affected by the presence of TBT. Interestingly, PXR and CYP3A mRNA levels were differentially affected, either decreased or increased, after exposure to TBT and forskolin, singly

  17. Feeding-dependent activation of enteric cells and sensory neurons by lymphatic fluid: evidence for a neurolymphocrine system.

    Science.gov (United States)

    Poole, Daniel P; Lee, Mike; Tso, Patrick; Bunnett, Nigel W; Yo, Sek Jin; Lieu, TinaMarie; Shiu, Amy; Wang, Jen-Chywan; Nomura, Daniel K; Aponte, Gregory W

    2014-04-15

    Lymphatic fluid is a plasma filtrate that can be viewed as having biological activity through the passive accumulation of molecules from the interstitial fluid. The possibility that lymphatic fluid is part of an active self-contained signaling process that parallels the endocrine system, through the activation of G-protein coupled receptors (GPCR), has remained unexplored. We show that the GPCR lysophosphatidic acid 5 (LPA5) is found in sensory nerve fibers expressing calcitonin gene-related peptide (CGRP) that innervate the lumen of lymphatic lacteals and enteric nerves. Using LPA5 as a model for nutrient-responsive GPCRs present on sensory nerves, we demonstrate that dietary protein hydrolysate (peptone) can induce c-Fos expression in enterocytes and nerves that express LPA5. Mesenteric lymphatic fluid (MLF) mobilizes intracellular calcium in cell models expressing LPA5 upon feeding in a time- and dose-dependent manner. Primary cultured neurons of the dorsal root ganglia expressing CGRP are activated by MLF, which is enhanced upon LPA5 overexpression. Activation is independent of the known LPA5 agonists, lysophosphatidic acid and farnesyl pyrophosphate. These data bring forth a pathway for the direct stimulation of sensory nerves by luminal contents and interstitial fluid. Thus, by activating LPA5 on sensory nerves, MLF provides a means for known and yet to be identified constituents of the interstitial fluid to act as signals to comprise a "neurolymphocrine" system.

  18. Autotaxin: A protein with two faces

    Energy Technology Data Exchange (ETDEWEB)

    Tania, Mousumi; Khan, Md. Asaduzzaman; Zhang, Huaiyuan; Li, Jinhua [Department of Biochemistry, School of Biological Science and Technology, Central South University, Changsha, Hunan 410013 (China); Song, Yuanda, E-mail: yuanda_song@hotmail.com [Department of Biochemistry, School of Biological Science and Technology, Central South University, Changsha, Hunan 410013 (China)

    2010-10-29

    Research highlights: {yields} Autotaxin (ATX) has lysophospholipase D activity. {yields} ATX catalyzes the formation of lysophosphatidic acid (LPA). {yields} LPA is a mitogen, and thus is responsible for cancer. {yields} ATX also catalyzes the formation of anti-cancerous cyclic phosphatidic acid. {yields} Autotaxin is a novel target of cancer therapy research. -- Abstract: Autotaxin (ATX) is a catalytic protein, which possesses lysophospholipase D activity, and thus involved in cellular membrane lipid metabolism and remodeling. Primarily, ATX was thought as a culprit protein for cancer, which potently stimulates cancer cell proliferation and tumor cell motility, augments the tumorigenicity and induces angiogenic responses. The product of ATX catalyzed reaction, lysophosphatidic acid (LPA) is a potent mitogen, which facilitates cell proliferation and migration, neurite retraction, platelet aggregation, smooth muscle contraction, actin stress formation and cytokine and chemokine secretion. In addition to LPA formation, later ATX has been found to catalyze the formation of cyclic phosphatidic acid (cPA), which have antitumor role by antimitogenic regulation of cell cycle, inhibition of cancer invasion and metastasis. Furthermore, the very attractive information to the scientists is that the LPA/cPA formation can be altered at different physiological conditions. Thus the dual role of ATX with the scope of product manipulation has made ATX a novel target for cancer treatment.

  19. Cardiac-specific inactivation of LPP3 in mice leads to myocardial dysfunction and heart failure

    Directory of Open Access Journals (Sweden)

    Mini Chandra

    2018-04-01

    Full Text Available Lipid Phosphate phosphatase 3 (LPP3, encoded by the Plpp3 gene, is an enzyme that dephosphorylates the bioactive lipid mediator lysophosphatidic acid (LPA. To study the role of LPP3 in the myocardium, we generated a cardiac specific Plpp3 deficient mouse strain. Although these mice were viable at birth in contrast to global Plpp3 knockout mice, they showed increased mortality ~ 8 months. LPP3 deficient mice had enlarged hearts with reduced left ventricular performance as seen by echocardiography. Cardiac specific Plpp3 deficient mice had longer ventricular effective refractory periods compared to their Plpp3 littermates. We observed that lack of Lpp3 enhanced cardiomyocyte hypertrophy based on analysis of cell surface area. We found that lack of Lpp3 signaling was mediated through the activation of Rho and phospho-ERK pathways. There are increased levels of fetal genes Natriuretic Peptide A and B (Nppa and Nppb expression indicating myocardial dysfunction. These mice also demonstrate mitochondrial dysfunction as evidenced by a significant decrease (P < 0.001 in the basal oxygen consumption rate, mitochondrial ATP production, and spare respiratory capacity as measured through mitochondrial bioenergetics. Histology and transmission electron microscopy of these hearts showed disrupted sarcomere organization and intercalated disc, with a prominent disruption of the cristae and vacuole formation in the mitochondria. Our findings suggest that LPA/LPP3-signaling nexus plays an important role in normal function of cardiomyocytes. Keywords: Heart failure, Lipid phosphate phosphatase, Lysophosphatidic acid

  20. Regulation of insulin-like growth factor I transcription by cyclic adenosine 3',5'-monophosphate (cAMP) in fetal rat bone cells through an element within exon 1: protein kinase A-dependent control without a consensus AMP response element

    Science.gov (United States)

    McCarthy, T. L.; Thomas, M. J.; Centrella, M.; Rotwein, P.

    1995-01-01

    Insulin-like growth factor I (IGF-I) is a locally synthesized anabolic growth factor for bone. IGF-I synthesis by primary fetal rat osteoblasts (Ob) is stimulated by agents that increase the intracellular cAMP concentration, including prostaglandin E2 (PGE2). Previous studies with Ob cultures demonstrated that PGE2 enhanced IGF-I transcription through selective use of IGF-I promoter 1, with little effect on IGF-I messenger RNA half-life. Transient transfection of Ob cultures with an array of promoter 1-luciferase reporter fusion constructs has now allowed localization of a potential cis-acting promoter element(s) responsible for cAMP-stimulated gene expression to the 5'-untranslated region (5'-UTR) of IGF-I exon 1, within a segment lacking a consensus cAMP response element. Our evidence derives from three principal observations: 1) a transfection construct containing only 122 nucleotides (nt) of promoter 1 and 328 nt of the 5'-UTR retained full PGE2-stimulated reporter expression; 2) maximal PGE2-driven reporter expression required the presence of nt 196 to 328 of exon 1 when tested within the context of IGF-I promoter 1; 3) cotransfection of IGF-I promoter-luciferase-reporter constructs with a plasmid encoding the alpha-isoform of the catalytic subunit of murine cAMP-dependent protein kinase (PKA) produced results comparable to those seen with PGE2 treatment, whereas cotransfection with a plasmid encoding a mutant regulatory subunit of PKA that cannot bind cAMP blocked PGE2-induced reporter expression. Deoxyribonuclease I footprinting of the 5'-UTR of exon 1 demonstrated protected sequences at HS3A, HS3B, and HS3D, three of six DNA-protein binding sites previously characterized with rat liver nuclear extracts. Of these three regions, only the HS3D binding site is located within the functionally identified hormonally responsive segment of IGF-I exon 1. These results directly implicate PKA in the control of IGF-I gene transcription by PGE2 and identify a segment of IGF-I exon 1 as being essential for this hormonal regulation.

  1. ¿La democracia es un sistema dependiente de valores como el conformismo y la obediencia? Un estudio comparado sobre las valoraciones que jóvenes y adultos españoles hacen de la democracia (Is democracy a dependent value such as conformity and obedience? A comparative study on the assestments that young and adult Spanish do of democracy

    Directory of Open Access Journals (Sweden)

    Liberto Carratalá Puertas

    2016-12-01

    Full Text Available Las investigaciones sobre la calidad de la democracia y la valoración que la ciudadanía realiza de ella han girado en torno a la influencia que el sistema económico o el político ejerce sobre las dimensiones que la componen. Los resultados han tenido un alcance explicativo limitado. Para superar este déficit se propone llevar a cabo un análisis de la cuestión desde una perspectiva que articule el nivel macro, la estructura política y económica, y micro, la subjetividad de la ciudadanía. Este trabajo abre una línea de investigación alternativa y complementaria a las ya existentes, con el objetivo de comprender cómo los valores humanos influyen en la valoración de la experiencia democrática de los jóvenes y adultos españoles. Los resultados, derivados del análisis de los datos con la técnica de los modelos de ecuaciones estructurales (SEM, ponen de relieve la diferencia existente entre jóvenes y adultos en sus respectivas valoraciones de la democracia, aunque coinciden en que es insatisfactoria. | The researches on democracy’s quality and the assessment citizens make of it have usually turned around the influence of economic or political systems applied on its dimensions. The results have had a limited explanatory range. In order to get over this shortfall, the proposal is the analysis from a perspective that will articulate macro and micro levels. This work will open an alternative and complementary research line to existing ones with the aim to understand how human values have influence on the assessment of the democratic experience from young and adult Spanish people. The results derived from data analysed with Structural Equation Models (SEM underline the difference between young’s and adult’s values of democracy even though they agree it is unsatisfying.

  2. A dependência pela prática de exercícios físicos e o uso de recursos ergogênicos - DOI: 10.4025/actascihealthsci.v32i1.4475 Physical exercise dependence and the use of ergogenic resources - DOI: 10.4025/actascihealthsci.v32i1.4475

    Directory of Open Access Journals (Sweden)

    Ricardo Aparecido Ferrarezi

    2009-12-01

    Full Text Available Objetivou-se Investigar a ocorrência de dependência por exercícios físicos quanto às características de praticantes de musculação e ginástica em academias, como uso de recursos ergogênicos, sexo e índice de massa corporal. Participaram do estudo 80 sujeitos (27,12 ± 6,60 anos, praticantes de ginástica e/ou musculação em academias, de ambos os sexos. Utilizou-se a Escala de Dependência por Exercícios Físicos, a listagem do tipo de suplemento alimentar utilizado como recurso ergogênico e o Índice de Massa Corporal – IMC (Kg/cm². A análise estatística foi realizada por meio da correlação de Spearman e o teste de Wilcoxon (p The aim of this study is to investigate the occurrence of physical exercise dependence in regards to the characteristics of participants in weight training and exercises at gyms, such as the use of ergogenic resources, gender and body mass index. Eighty subjects (27.12 ± 6.60 years from both genders took part in the study, all of whom practiced gymnastics and/or weight training in gyms. The study utilized the Exercise Dependence Scale, a check list of the kinds of nutritional supplementation used as ergogenic resources, and the Body Mass Index – BMI (Kg cm-². Statistical analysis was performed using Spearman's correlation and the Wilcoxon test (p < 0.05. The results showed that there was no statistically significant difference between physical exercise dependence in men (5.14 ± 1.28 and women (5.60 ± 1.45. The body mass index did not show statistically significant correlation with the scores of dependency, either. However, dependent men showed high prevalence of use of ergogenic resources (63.63%, p = 0.01, while for dependent women there were no statistically significant results. The body mass index does not relate to the scores of exercise dependence. However, even with a normal BMI, the use of ergogenic resources presents high prevalence among dependent men. As a result, there is evidence that physical exercise dependence is a risk factor for the development of emotional disturbances related to exercise, such as muscle dysmorphia and overtraining.

  3. O estresse físico e a dependência de exercício físico El estrés físico y la dependencia de ejercicio físico Physical stress and physical exercise dependence

    Directory of Open Access Journals (Sweden)

    Hanna K.M. Antunes

    2006-10-01

    Full Text Available O objetivo do presente estudo foi verificar os escores referentes à escala de dependência de exercício, qualidade de vida, bem como os escores indicativos de humor em atletas de corrida de aventura (CA. Participaram deste estudo 17 atletas de ambos os gêneros com histórico de prática da modalidade de pelo menos três anos, com experiência em provas nacionais e internacionais e que figuram nas primeiras posições do ranking brasileiro. A média (± desvio-padrão da idade, altura, massa corporal, índice de massa corpórea (IMC e consumo de oxigênio foram: 31,11 ± 6,30 anos; 1,73 ± 0,07cm; 70,75 ± 7,96kg; 23,48 ± 1,48kg/m² e 58,70 ± 6,63ml.min¹.kg¹, respectivamente. Os voluntários responderam aos seguintes questionários: Escala de Dependência de Exercício (EDE, Idate Traço e Estado, Profile of Mood States (POMS, SF-36 Pesquisa em Saúde e Questionário de Padrão Social. Os resultados revelaram que os escores observados na EDE foram indicativos de dependência de exercício; já os questionários de humor revelaram ansiedade moderada, enquanto o POMS não detectou escores indicativos de distúrbios de humor. Quanto à qualidade de vida, a média das oito dimensões referentes ao questionário SF-36 se mostrou acima de 85%, sugerindo que, apesar de haver dependência de exercício, parece que esse fato não foi capaz de promover alterações significativas no estado de humor e na qualidade de vida. Esses dados sugerem que atletas de CA apresentam dependência de exercício não associada aos distúrbios de humor.El objetivo del presente estudio ha sido el de verificar los escores referentes a la escala de dependencia de ejercicio, calidad de vida, así como los escores indicativos de humor en atletas de Carrera de Aventura (CA. Participaron de este estudio 17 atletas de ambos géneros con histórico de práctica de la modalidad de por lo menos tres años, con experiencia en pruebas nacionales e internacionales y que figuran en las primeras posiciones del ranking brasileño. La media (± desvío padrón de edad, altura, masa corporal, índice de masa corpórea (IMC y consumo de oxígeno fueron: 31,11 ± 6,30 años; 1,73 ± 0,07 cm; 70,75 ± 7,96 kg; 23,48 ± 1,48 kg/m² y 58,70 ± 6,63 ml.min-1.kg-1, respectivamente. Los voluntarios respondieron a los siguientes cuestionarios: Escala de Dependencia de Ejercicio (EDE, "Idate Traço" y Estado, Profile of Mood States (POMS, SF-36 Investigación e Salud y Cuestionario de Padrón Social. Los resultados revelaron que los escores observados en la EDE fueron indicativos de dependencia de ejercicio, mientras que los cuestionarios de humor revelaron ansiedad moderada, entretanto el POMS no detectó escores indicativos de disturbios de humor. En relación a la calidad de vida, la media de las 8 dimensiones referentes al cuestionario SF-36 se mostró por encima de 85%, lo que sugiere que a pesar de haber dependencia de ejercicio, parece que ese hecho no fue capaz de promover alteraciones significativas en el estado de humor y en la calidad de vida. Nuestros datos sugieren que atletas de CA presentan dependencia de ejercicio no asociada a los disturbios de humor.The aim of this study was to verify the referring scores of exercise dependence, quality of life as well as the mood indicators in adventure race (AR athletes. 17 athletes of both sexes participated in the study and all had a history of three years in this modality, with national and international experience, and figured in the first positions in the Brazilian ranking. The age, height, weight, body mass index (BMI and oxygen uptake averages ± standard deviations were: 31.11 ± 6.30 years; 1.73 ± 0.07 cm; 70.75 ± 7.96 kg; 23.48 ± 1.48 wt/ht² and 58.70 ± 6.63 ml.min-1.kg-1, respectively. The volunteers were given the following questionnaires: Exercise Dependency Scale (EDE, Idate Trait and State, Profile of Mood States (POMS, SF-36 Health Research and Social Patterns Questionnaire. The results showed that scores in EDE indicated exercise dependence, and the mood questionnaires revealed moderate anxiety, while the POMS did not detect any indicative scores of mood disorders. Concerning the quality of life, the average of 8 dimensions of the SF-36 was higher than 85%, suggesting that although there was exercise dependence, this fact alone did not promote significant alterations in mood and quality of life. Thus, our data suggested that athletes of AR have exercise dependence not associated to mood disorders.

  4. Novel lysophosphoplipid receptors: their structure and function.

    Science.gov (United States)

    Makide, Kumiko; Uwamizu, Akiharu; Shinjo, Yuji; Ishiguro, Jun; Okutani, Michiyo; Inoue, Asuka; Aoki, Junken

    2014-10-01

    It is now accepted that lysophospholipids (LysoGPs) have a wide variety of functions as lipid mediators that are exerted through G protein-coupled receptors (GPCRs) specific to each lysophospholipid. While the roles of some LysoGPs, such as lysophosphatidic acid and sphingosine 1-phosphate, have been thoroughly examined, little is known about the roles of several other LysoGPs, such as lysophosphatidylserine (LysoPS), lysophosphatidylthreonine, lysophosphatidylethanolamine, lysophosphatidylinositol (LPI), and lysophosphatidylglycerol. Recently, a GPCR was found for LPI (GPR55) and three GPCRs (GPR34/LPS1, P2Y10/LPS2, and GPR174/LPS3) were found for LysoPS. In this review, we focus on these newly identified GPCRs and summarize the actions of LysoPS and LPI as lipid mediators. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  5. Non-cell autonomous and non-catalytic activities of ATX in the developing brain

    Directory of Open Access Journals (Sweden)

    Raanan eGreenman

    2015-03-01

    Full Text Available The intricate formation of the cerebral cortex requires a well-coordinated series of events, which are regulated at the level of cell-autonomous and non-cell autonomous mechanisms. Whereas cell-autonomous mechanisms that regulate cortical development are well-studied, the non cell-autonomous mechanisms remain poorly understood. A non-biased screen allowed us to identify Autotaxin (ATX as a non cell-autonomous regulator of neural stem cell proliferation. ATX (also known as ENPP2 is best known to catalyze lysophosphatidic acid (LPA production. Our results demonstrate that ATX affects the localization and adhesion of neuronal progenitors in a cell autonomous and non-cell autonomous manner, and strikingly, this activity is independent from its catalytic activity in producing LPA.

  6. Autotaxin overexpression causes embryonic lethality and vascular defects.

    Directory of Open Access Journals (Sweden)

    Hiroshi Yukiura

    Full Text Available Autotaxin (ATX is a secretory protein, which converts lysophospholipids to lysophosphatidic acid (LPA, and is essential for embryonic vascular formation. ATX is abundantly detected in various biological fluids and its level is elevated in some pathophysiological conditions. However, the roles of elevated ATX levels remain to be elucidated. In this study, we generated conditional transgenic (Tg mice overexpressing ATX and examined the effects of excess LPA signalling. We found that ATX overexpression in the embryonic period caused severe vascular defects and was lethal around E9.5. ATX was conditionally overexpressed in the neonatal period using the Cre/loxP system, which resulted in a marked increase in the plasma LPA level. This resulted in retinal vascular defects including abnormal vascular plexus and increased vascular regression. Our findings indicate that the ATX level must be carefully regulated to ensure coordinated vascular formation.

  7. ATX-LPA1 axis contributes to proliferation of chondrocytes by regulating fibronectin assembly leading to proper cartilage formation.

    Science.gov (United States)

    Nishioka, Tatsuji; Arima, Naoaki; Kano, Kuniyuki; Hama, Kotaro; Itai, Eriko; Yukiura, Hiroshi; Kise, Ryoji; Inoue, Asuka; Kim, Seok-Hyung; Solnica-Krezel, Lilianna; Moolenaar, Wouter H; Chun, Jerold; Aoki, Junken

    2016-03-23

    The lipid mediator lysophosphatidic acid (LPA) signals via six distinct G protein-coupled receptors to mediate both unique and overlapping biological effects, including cell migration, proliferation and survival. LPA is produced extracellularly by autotaxin (ATX), a secreted lysophospholipase D, from lysophosphatidylcholine. ATX-LPA receptor signaling is essential for normal development and implicated in various (patho)physiological processes, but underlying mechanisms remain incompletely understood. Through gene targeting approaches in zebrafish and mice, we show here that loss of ATX-LPA1 signaling leads to disorganization of chondrocytes, causing severe defects in cartilage formation. Mechanistically, ATX-LPA1 signaling acts by promoting S-phase entry and cell proliferation of chondrocytes both in vitro and in vivo, at least in part through β1-integrin translocation leading to fibronectin assembly and further extracellular matrix deposition; this in turn promotes chondrocyte-matrix adhesion and cell proliferation. Thus, the ATX-LPA1 axis is a key regulator of cartilage formation.

  8. Autotaxin Overexpression Causes Embryonic Lethality and Vascular Defects

    Science.gov (United States)

    Yukiura, Hiroshi; Kano, Kuniyuki; Kise, Ryoji; Inoue, Asuka; Aoki, Junken

    2015-01-01

    Autotaxin (ATX) is a secretory protein, which converts lysophospholipids to lysophosphatidic acid (LPA), and is essential for embryonic vascular formation. ATX is abundantly detected in various biological fluids and its level is elevated in some pathophysiological conditions. However, the roles of elevated ATX levels remain to be elucidated. In this study, we generated conditional transgenic (Tg) mice overexpressing ATX and examined the effects of excess LPA signalling. We found that ATX overexpression in the embryonic period caused severe vascular defects and was lethal around E9.5. ATX was conditionally overexpressed in the neonatal period using the Cre/loxP system, which resulted in a marked increase in the plasma LPA level. This resulted in retinal vascular defects including abnormal vascular plexus and increased vascular regression. Our findings indicate that the ATX level must be carefully regulated to ensure coordinated vascular formation PMID:25992708

  9. Non-cell autonomous and non-catalytic activities of ATX in the developing brain.

    Science.gov (United States)

    Greenman, Raanan; Gorelik, Anna; Sapir, Tamar; Baumgart, Jan; Zamor, Vanessa; Segal-Salto, Michal; Levin-Zaidman, Smadar; Aidinis, Vassilis; Aoki, Junken; Nitsch, Robert; Vogt, Johannes; Reiner, Orly

    2015-01-01

    The intricate formation of the cerebral cortex requires a well-coordinated series of events, which are regulated at the level of cell-autonomous and non-cell autonomous mechanisms. Whereas cell-autonomous mechanisms that regulate cortical development are well-studied, the non-cell autonomous mechanisms remain poorly understood. A non-biased screen allowed us to identify Autotaxin (ATX) as a non-cell autonomous regulator of neural stem cells. ATX (also known as ENPP2) is best known to catalyze lysophosphatidic acid (LPA) production. Our results demonstrate that ATX affects the localization and adhesion of neuronal progenitors in a cell autonomous and non-cell autonomous manner, and strikingly, this activity is independent from its catalytic activity in producing LPA.

  10. The Bulk of Autotaxin Activity Is Dispensable for Adult Mouse Life.

    Directory of Open Access Journals (Sweden)

    Aggeliki Katsifa

    Full Text Available Autotaxin (ATX, Enpp2 is a secreted lysophospholipase D catalysing the production of lysophosphatidic acid, a pleiotropic growth factor-like lysophospholipid. Increased ATX expression has been detected in a number of chronic inflammatory diseases and different types of cancer, while genetic interventions have proven a role for ATX in disease pathogenesis. Therefore, ATX has emerged as a potential drug target and a large number of ATX inhibitors have been developed exhibiting promising therapeutic potential. However, the embryonic lethality of ATX null mice and the ubiquitous expression of ATX and LPA receptors in adult life question the suitability of ATX as a drug target. Here we show that inducible, ubiquitous genetic deletion of ATX in adult mice, as well as long-term potent pharmacologic inhibition, are well tolerated, alleviating potential toxicity concerns of ATX therapeutic targeting.

  11. Lysoglycerophospholipids in chronic inflammatory disorders: the PLA(2)/LPC and ATX/LPA axes.

    Science.gov (United States)

    Sevastou, Ioanna; Kaffe, Eleanna; Mouratis, Marios-Angelos; Aidinis, Vassilis

    2013-01-01

    Lysophosphatidylcholine (LPC) and lysophosphatidic acid (LPA), the most prominent lysoglycerophospholipids, are emerging as a novel class of inflammatory lipids, joining thromboxanes, leukotrienes and prostaglandins with which they share metabolic pathways and regulatory mechanisms. Enzymes that participate in LPC and LPA metabolism, such as the phospholipase A(2) superfamily (PLA(2)) and autotaxin (ATX, ENPP2), play central roles in regulating LPC and LPA levels and consequently their actions. LPC/LPA biosynthetic pathways will be briefly presented and LPC/LPA signaling properties and their possible functions in the regulation of the immune system and chronic inflammation will be reviewed. Furthermore, implications of exacerbated LPC and/or LPA signaling in the context of chronic inflammatory diseases, namely rheumatoid arthritis, multiple sclerosis, pulmonary fibrosis and hepatitis, will be discussed. This article is part of a Special Issue entitled Advances in Lysophospholipid Research. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Autotaxin expression from synovial fibroblasts is essential for the pathogenesis of modeled arthritis

    Science.gov (United States)

    Nikitopoulou, Ioanna; Oikonomou, Nikos; Karouzakis, Emmanuel; Sevastou, Ioanna; Nikolaidou-Katsaridou, Nefeli; Zhao, Zhenwen; Mersinias, Vassilis; Armaka, Maria; Xu, Yan; Masu, Masayuki; Mills, Gordon B.; Gay, Steffen; Kollias, George

    2012-01-01

    Rheumatoid arthritis is a destructive arthropathy characterized by chronic synovial inflammation that imposes a substantial socioeconomic burden. Under the influence of the proinflammatory milieu, synovial fibroblasts (SFs), the main effector cells in disease pathogenesis, become activated and hyperplastic, releasing proinflammatory factors and tissue-remodeling enzymes. This study shows that activated arthritic SFs from human patients and animal models express significant quantities of autotaxin (ATX; ENPP2), a lysophospholipase D that catalyzes the conversion of lysophosphatidylcholine to lysophosphatidic acid (LPA). ATX expression from SFs was induced by TNF, and LPA induced SF activation and effector functions in synergy with TNF. Conditional genetic ablation of ATX in mesenchymal cells, including SFs, resulted in disease attenuation in animal models of arthritis, establishing the ATX/LPA axis as a novel player in chronic inflammation and the pathogenesis of arthritis and a promising therapeutic target. PMID:22493518

  13. New insights into the autotaxin/LPA axis in cancer development and metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Leblanc, Raphaël; Peyruchaud, Olivier, E-mail: olivier.peyruchaud@inserm.fr

    2015-05-01

    Lysophosphatidic acid (LPA) is a simple lipid with a single fatty acyl chain linked to a glycerophosphate backbone. Despite the simplicity of its structure but owing to its interactions with a series of at least six G protein-coupled receptors (LPA{sub 1–6}), LPA exerts pleiotropic bioactivities including stimulation of proliferation, migration and survival of many cell types. Autotaxin (ATX) is a unique enzyme with a lysophospholipase D (lysoPLD) activity that is responsible for the levels of LPA in the blood circulation. Both LPA receptor family members and ATX/LysoPLD are aberrantly expressed in many human cancers. This review will present the more striking as well as novel experimental evidences using cell lines, cancer mouse models and transgenic animals identifying the roles for ATX and LPA receptors in cancer progression, tumor cell invasion and metastasis.

  14. Yap is required for ependymal integrity and is suppressed in LPA-induced hydrocephalus

    Science.gov (United States)

    Park, Raehee; Moon, Uk Yeol; Park, Jun Young; Hughes, Lucinda J.; Johnson, Randy L.; Cho, Seo-Hee; Kim, Seonhee

    2016-01-01

    Timely generation and normal maturation of ependymal cells along the aqueduct are critical for preventing physical blockage between the third and fourth ventricles and the development of fetal non-communicating hydrocephalus. Our study identifies Yap, the downstream effector of the evolutionarily conserved Hippo pathway, as a central regulator for generating developmentally controlled ependymal cells along the ventricular lining of the aqueduct. Yap function is necessary for proper proliferation of progenitors and apical attachment of ependymal precursor cells. Importantly, an injury signal initiated by lysophosphatidic acid (LPA), an upstream regulator of Yap that can cause fetal haemorrhagic hydrocephalus, deregulates Yap in the developing aqueduct. LPA exposure leads to the loss of N-cadherin concentrations at the apical endfeet, which can be partially restored by forced Yap expression and more efficiently by phosphomimetic Yap. These results reveal a novel function of Yap in retaining tissue junctions during normal development and after fetal brain injury. PMID:26754915

  15. Alterations of red cell membrane properties in neuroacanthocytosis.

    Directory of Open Access Journals (Sweden)

    Claudia Siegl

    Full Text Available Neuroacanthocytosis (NA refers to a group of heterogenous, rare genetic disorders, namely chorea acanthocytosis (ChAc, McLeod syndrome (MLS, Huntington's disease-like 2 (HDL2 and pantothenate kinase associated neurodegeneration (PKAN, that mainly affect the basal ganglia and are associated with similar neurological symptoms. PKAN is also assigned to a group of rare neurodegenerative diseases, known as NBIA (neurodegeneration with brain iron accumulation, associated with iron accumulation in the basal ganglia and progressive movement disorder. Acanthocytosis, the occurrence of misshaped erythrocytes with thorny protrusions, is frequently observed in ChAc and MLS patients but less prevalent in PKAN (about 10% and HDL2 patients. The pathological factors that lead to the formation of the acanthocytic red blood cell shape are currently unknown. The aim of this study was to determine whether NA/NBIA acanthocytes differ in their functionality from normal erythrocytes. Several flow-cytometry-based assays were applied to test the physiological responses of the plasma membrane, namely drug-induced endocytosis, phosphatidylserine exposure and calcium uptake upon treatment with lysophosphatidic acid. ChAc red cell samples clearly showed a reduced response in drug-induced endovesiculation, lysophosphatidic acid-induced phosphatidylserine exposure, and calcium uptake. Impaired responses were also observed in acanthocyte-positive NBIA (PKAN red cells but not in patient cells without shape abnormalities. These data suggest an "acanthocytic state" of the red cell where alterations in functional and interdependent membrane properties arise together with an acanthocytic cell shape. Further elucidation of the aberrant molecular mechanisms that cause this acanthocytic state may possibly help to evaluate the pathological pathways leading to neurodegeneration.

  16. The Peanut (Arachis hypogaea L. Gene AhLPAT2 Increases the Lipid Content of Transgenic Arabidopsis Seeds.

    Directory of Open Access Journals (Sweden)

    Silong Chen

    Full Text Available Lysophosphatidic acid acyltransferase (LPAT, which converts lysophosphatidic acid (LPA to phosphatidic acid (PA, catalyzes the addition of fatty acyl moieties to the sn-2 position of the LPA glycerol backbone in triacylglycerol (TAG biosynthesis. We recently reported the cloning and temporal-spatial expression of a peanut (Arachis hypogaea AhLPAT2gene, showing that an increase in AhLPAT2 transcript levels was closely correlated with an increase in seed oil levels. However, the function of the enzyme encoded by the AhLPAT2 gene remains unclear. Here, we report that AhLPAT2 transcript levels were consistently higher in the seeds of a high-oil cultivar than in those of a low-oil cultivar across different seed developmental stages. Seed-specific overexpression of AhLPAT2 in Arabidopsis results in a higher percentage of oil in the seeds and greater-than-average seed weight in the transgenic plants compared with the wild-type plants, leading to a significant increase in total oil yield per plant. The total fatty acid (FA content and the proportion of unsaturated FAs also increased. In the developing siliques of AhLPAT2-overexpressing plants, the expression levels of genes encoding crucial enzymes involved in de novo FA synthesis, acetyl-CoA subunit (AtBCCP2 and acyl carrier protein 1 (AtACP1 were elevated. AhLPAT2 overexpression also promoted the expression of several key genes related to TAG assembly, sucrose metabolism, and glycolysis. These results demonstrate that the expression of AhLPAT2 plays an important role in glycerolipid production in peanuts.

  17. História da enfermagem psiquiátrica e a dependência química no Brasil: atravessando a história para reflexão Historia de la enfermería psiquiátrica y la dependencia química en el Brasil: atravesando la historia para la reflexión History of the psychiatric nursing and chemical dependency in Brazil: crossing the history for reflection

    OpenAIRE

    Amanda Márcia dos Santos Reinaldo; Sandra Cristina Pillon

    2007-01-01

    A formação do enfermeiro em Enfermagem Psiquiátrica e na área de dependências químicas norteia a discussão desse artigo, tendo em vista a complexidade dos problemas relacionados ao ensino de enfermagem, saúde mental, psiquiatria e álcool e drogas. Trata-se de um artigo de revisão de literatura onde as autoras compilaram fontes primárias e secundárias sobre o tema e, a partir da leitura do material bibliográfico, fizeram análises e reflexões acerca dos atravessamentos históricos que permeiam a...

  18. Generation of Self-Renewing Hepatoblasts From Human Embryonic Stem Cells by Chemical Approaches.

    Science.gov (United States)

    Zhang, Muzi; Sun, Pingxin; Wang, Yusheng; Chen, Junnan; Lv, Linjie; Wei, Wanguo; Jin, Caixia; Li, Wenlin

    2015-11-01

    Somatic stem cells play crucial roles in organogenesis and tissue homeostasis and regeneration and may ultimately prove useful for cell therapy for a variety of degenerative diseases and injuries; however, isolation and expansion of most types of somatic stem cells from tissues are technically challenging. Human pluripotent stem cells are a renewable source for any adult cell types, including somatic stem cells. Generation of somatic stem cells from human pluripotent stem cells is a promising strategy to get these therapeutically valuable cells. Previously, we developed a chemically defined condition for mouse hepatoblast self-renewal through a reiterative screening strategy. In the present study, we efficiently generated hepatoblasts from human embryonic stem cells by a stepwise induction strategy. Importantly, these human embryonic stem cell-derived hepatoblasts can be captured and stably maintained using conditions previously established for mouse hepatoblast self-renewal, which includes basal media supplemented with insulin, transferrin, sodium selenite, epidermal growth factor, glycogen synthase kinase 3 inhibitor, transforming growth factor β receptor inhibitor, lysophosphatidic acid, and sphingosine 1-phosphate. The cells can stably retain hepatoblast phenotypes during prolonged culture and can differentiate into mature hepatocytes through in vitro provision of hepatocyte lineage developmental cues. After being embedded into three-dimensional Matrigel, these cells efficiently formed bile duct-like structures resembling native bile duct tissues. These human embryonic stem cell-derived hepatoblasts would be useful as a renewable source for cell therapy of liver diseases. Somatic stem cells have been proposed as promising candidates for cell-based therapy; however, isolation of somatic stem cells from adult tissues is usually invasive and technically challenging. In the present study, hepatoblasts from human embryonic stem cells were efficiently generated

  19. Regulation of T cell motility in vitro and in vivo by LPA and LPA2.

    Directory of Open Access Journals (Sweden)

    Sara A Knowlden

    Full Text Available Lysophosphatidic acid (LPA and the LPA-generating enzyme autotaxin (ATX have been implicated in lymphocyte trafficking and the regulation of lymphocyte entry into lymph nodes. High local concentrations of LPA are thought to be present in lymph node high endothelial venules, suggesting a direct influence of LPA on cell migration. However, little is known about the mechanism of action of LPA, and more work is needed to define the expression and function of the six known G protein-coupled receptors (LPA 1-6 in T cells. We studied the effects of 18∶1 and 16∶0 LPA on naïve CD4+ T cell migration and show that LPA induces CD4+ T cell chemorepulsion in a Transwell system, and also improves the quality of non-directed migration on ICAM-1 and CCL21 coated plates. Using intravital two-photon microscopy, lpa2-/- CD4+ T cells display a striking defect in early migratory behavior at HEVs and in lymph nodes. However, later homeostatic recirculation and LPA-directed migration in vitro were unaffected by loss of lpa2. Taken together, these data highlight a previously unsuspected and non-redundant role for LPA2 in intranodal T cell motility, and suggest that specific functions of LPA may be manipulated by targeting T cell LPA receptors.

  20. Autotaxin (ATX): a multi-functional and multi-modular protein possessing enzymatic lysoPLD activity and matricellular properties.

    Science.gov (United States)

    Yuelling, Larra M; Fuss, Babette

    2008-09-01

    Recent studies have established that autotaxin (ATX), also known as phosphodiesterase Ialpha/autotaxin (PD-Ialpha/ATX) or (ecto)nucleotide pyrophosphatase/phosphodiesterase 2 [(E)NPP2], represents a multi-functional and multi-modular protein. ATX was initially thought to function exclusively as a phosphodiesterase/pyrophosphatase. However, it has become apparent that this enzymatically active site, which is ultimately responsible for ATX's originally discovered property of tumor cell motility stimulation, mediates the conversion of lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA). In addition, a separate functionally active domain, here referred to as the Modulator of Oligodendrocyte Remodeling and Focal adhesion Organization (MORFO) domain, was discovered in studies analyzing the role of ATX during the differentiation of myelinating cells of the central nervous system (CNS), namely oligodendrocytes. This novel domain was found to mediate anti-adhesive, i.e. matricellular, properties and to promote morphological maturation of oligodendrocytes. In this review, we summarize our current understanding of ATX's structure-function domains and discuss their contribution to the presently known main functional roles of ATX.

  1. ATX expression and LPA signalling are vital for the development of the nervous system.

    Science.gov (United States)

    Fotopoulou, Stella; Oikonomou, Nikos; Grigorieva, Elena; Nikitopoulou, Ioanna; Paparountas, Triantafillos; Thanassopoulou, Artemis; Zhao, Zhenwen; Xu, Yan; Kontoyiannis, Dimitris L; Remboutsika, Eumorphia; Aidinis, Vassilis

    2010-03-15

    Autotaxin (ATX) is a secreted glycoprotein widely present in biological fluids, originally isolated from the supernatant of melanoma cells as an autocrine motility stimulation factor. Its enzymatic product, lysophosphatidic acid (LPA), is a phospholipid mediator that evokes growth-factor-like responses in almost all cell types through G-protein coupled receptors. To assess the role of ATX and LPA signalling in pathophysiology, a conditional knockout mouse was created. Ubiquitous, obligatory deletion resulted to embryonic lethality most likely due to aberrant vascular branching morphogenesis and chorio-allantoic fusion. Moreover, the observed phenotype was shown to be entirely depended on embryonic, but not extraembryonic or maternal ATX expression. In addition, E9.5 ATX null mutants exhibited a failure of neural tube closure, most likely independent of the circulatory failure, which correlated with decreased cell proliferation and increased cell death. More importantly, neurite outgrowth in embryo explants was severely compromised in mutant embryos but could be rescued upon the addition of LPA, thus confirming a role for ATX and LPA signalling in the development of the nervous system. Finally, expression profiling of mutant embryos revealed attenuated embryonic expression of HIF-1a in the absence of ATX, suggesting a novel effector pathway of ATX/LPA. Copyright 2010 Elsevier Inc. All rights reserved.

  2. Interaction of platelet-derived autotaxin with tumor integrin αVβ3 controls metastasis of breast cancer cells to bone

    Science.gov (United States)

    Leblanc, Raphael; Lee, Sue-Chin; David, Marion; Bordet, Jean-Claude; Norman, Derek D.; Patil, Renukadevi; Miller, Duane; Sahay, Debashish; Ribeiro, Johnny; Clézardin, Philippe; Tigyi, Gabor J.

    2014-01-01

    Autotaxin (ATX), through its lysophospholipase D activity controls physiological levels of lysophosphatidic acid (LPA) in blood. ATX is overexpressed in multiple types of cancers, and together with LPA generated during platelet activation promotes skeletal metastasis of breast cancer. However, the pathophysiological sequelae of regulated interactions between circulating LPA, ATX, and platelets remain undefined in cancer. In this study, we show that ATX is stored in α-granules of resting human platelets and released upon tumor cell-induced platelet aggregation, leading to the production of LPA. Our in vitro and in vivo experiments using human breast cancer cells that do not express ATX (MDA-MB-231 and MDA-B02) demonstrate that nontumoral ATX controls the early stage of bone colonization by tumor cells. Moreover, expression of a dominant negative integrin αvβ3-Δ744 or treatment with the anti-human αvβ3 monoclonal antibody LM609, completely abolished binding of ATX to tumor cells, demonstrating the requirement of a fully active integrin αvβ3 in this process. The present results establish a new mechanism for platelet contribution to LPA-dependent metastasis of breast cancer cells, and demonstrate the therapeutic potential of disrupting the binding of nontumor-derived ATX with the tumor cells for the prevention of metastasis. PMID:25277122

  3. HIV-1 Tat Inhibits Autotaxin Lysophospholipase D Activity and Modulates Oligodendrocyte Differentiation

    Science.gov (United States)

    Wheeler, Natalie A.; Fuss, Babette; Knapp, Pamela E.

    2016-01-01

    White matter injury has been frequently reported in HIV+ patients. Previous studies showed that HIV-1 Tat (transactivator of transcription), a viral protein that is produced and secreted by HIV-infected cells, is toxic to young, immature oligodendrocytes (OLGs). Adding Tat to the culture medium reduced the viability of immature OLGs, and the surviving OLGs exhibited reduced process networks. OLGs produce and secrete autotaxin (ATX), an ecto-enzyme containing a lysophospholipase D (lysoPLD) activity that converts lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), a lipid signaling molecule that stimulates OLG differentiation. We hypothesized that Tat affects OLG development by interfering with the ATX-LPA signaling pathway. Our data show that Tat treatment leads to changes in the expression of OLG differentiation genes and the area of OLG process networks, both of which can be rescued by LPA. Tat-treated OLGs showed no change in LPA receptor expression but significantly decreased extracellular ATX levels and lysoPLD activity. In Tat transgenic mice, expression of Tat in vivo leads to decreased OLG ATX secretion. Furthermore, co-immunoprecipitation experiments revealed a potential physical interaction between Tat and ATX. Together, these data strongly suggest two functional implications of Tat blocking ATX’s lysoPLD activity. On one hand, it attenuates OLG differentiation, and on the other hand it interferes with the protective effects of LPA on OLG process morphology. PMID:27659560

  4. Cholera toxin inhibits human hepatocarcinoma cell proliferation in vitro via suppressing ATX/LPA axis.

    Science.gov (United States)

    Xia, Qi; Deng, An-mei; Wu, Shan-shan; Zheng, Min

    2011-08-01

    To investigate the antitumor effect of cholera toxin (CT) in hepatocellular carcinoma (HCC) in vitro and the mechanisms underlying the effect. Human hepatocellular carcinoma cell lines Hep3B and Huh7, which expressed moderate and high level of autotaxin (ATX), respectively, were used. Cytokine level in the cells was evaluated using ELISA assay, and cell proliferation was investigated using MTT assay. ATX expression was determined using Western blot. ATX/lyso-PLD activity in the conditioned medium was measured using FS-3, a fluorescent lysophosphatidylcholine (LPC) analogue, as substrate. Exposure to CT (7.5 and 10 ng/mL) significantly inhibited the cell growth, decreased secretion of proinflammatory cytokine TNF-α and promoted secretion of anti-inflammatory cytokines IL-4 and IL-10. CT at 10 ng/mL markedly suppressed ATX expression in Hep3B and Huh7 cells. Furthermore, ATX and lysophosphatidic acid (LPA) were found to be crucial for growth of the cancer cells. CT could inhibit TNF-α-induced expression and secretion of ATX that led to decreased activity of lysophospholipase D, thus decreasing the conversion of LPC to LPA. CT inhibits hepatocellular carcinoma cell growth in vitro via regulating the ATX-LPA pathway.

  5. Blocking gp130 signaling suppresses autotaxin expression in adipocytes and improves insulin sensitivity in diet-induced obesity.

    Science.gov (United States)

    Sun, Shuhong; Wang, Ran; Song, Jianwen; Guan, Ming; Li, Na; Zhang, Xiaotian; Zhao, Zhenwen; Zhang, Junjie

    2017-11-01

    Autotaxin (ATX), which is highly expressed and secreted by adipocytes, functions as the key enzyme to generate lysophosphatidic acid (LPA) from lysophosphatidylcholine. Adipose tissue is the main source of circulating ATX that modulates plasma LPA levels. Upregulation of ATX expression in obese patients and mice is closely related with insulin resistance and impaired glucose tolerance. However, the mechanism of ATX expression in adipocytes remains largely unknown. In this study, we found that glycoprotein 130 (gp130)-mediated Janus kinase (JAK)-signal transducer and activator of transcription 3 (STAT3) activation was required for abundant ATX expression in adipocytes. Through gp130, the interleukin 6 (IL-6) family cytokines, such as IL-6, leukemia inhibitory factor, cardiotrophin-1, and ciliary neurotrophic factor, upregulated ATX expression in adipocytes. ATX contributes to the induction of insulin resistance and lipolysis in IL-6-stimulated adipocytes. Oral administration of gp130 inhibitor SC144 suppressed ATX expression in adipose tissue, decreased plasma ATX, LPA, and FFA levels, and significantly improved insulin sensitivity and glucose tolerance in high-fat diet-fed obese mice. In summary, our results indicate that the activation of gp130-JAK-STAT3 pathway by IL-6 family cytokines has an important role in regulating ATX expression in adipocytes and that gp130 is a promising target in the management of obesity-associated glucose metabolic diseases. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  6. ATX-LPA axis induces expression of OPN in hepatic cancer cell SMMC7721.

    Science.gov (United States)

    Zhang, Rihua; Zhang, Zhihong; Pan, Xiaolin; Huang, Xiayue; Huang, Zuhu; Zhang, Guoxin

    2011-03-01

    Osteopontin (OPN) and autotaxin (ATX) are important chemokines involved in the survival, proliferation, migration, invasion, and metastasis of many cancer cells. The focus of the study was to investigate the relationship between OPN and ATX-lysophosphatidic acid (LPA) axis. The expression of OPN and its cellular cascades were determined by western blot and real-time quantitative transcription polymerase chain reaction (real-time PCR) analyses. Cell migration activity was determined by a Transwell-migration assay. In comparison with nontreated cells, we found that the ATX-LPA axis upregulated OPN expression by 2.91-fold in protein levels and 2.52-fold in mRNA levels. The ATX-LPA axis activates Akt and ATX/LPC-induced OPN expression in SMMC7721 cells was largely reduced by the inhibitors of phosphatidylinositol 3-kinase (PI3K)/Akt or LPA receptor. This study provides the first evidence that the induction of the OPN expression by ATX-LPA axis was mediated by the activation of Akt through LPA receptors and OPN was required for migration of SMMC7721 cells induced by ATX-LPA axis. Copyright © 2010 Wiley-Liss, Inc.

  7. ATX and LPA receptor 3 are coordinately up-regulated in lipopolysaccharide-stimulated THP-1 cells through PKR and SPK1-mediated pathways.

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    Li, Song; Xiong, Chaoyang; Zhang, Junjie

    2012-03-23

    Lysophosphatidic acid (LPA) is an important phospholipid mediator in inflammation and immunity. Previously, we showed that autotaxin (ATX), the enzyme producing LPA from lysophosphatidylcholine (LPC), is induced by LPS in THP-1 cells via the activation of PKR, JNK and p38 MAPK. In this study, we find that ATX and LPA receptor 3 (LPA(3)) are coordinately up-regulated in LPS-stimulated THP-1 cells. PKR-mediated activation of JNK1 and p38 MAPK is required for both ATX and LPA(3) up-regulation. SPK1-mediated activation of the PI3K-AKT-β-catenin pathway is essential for ATX induction, while SPK1-mediated ERK activation is required for LPA(3) up-regulation. Either ATX or LPA(3) knockdown inhibited CCL8 induction by LPS, suggesting that ATX and LPA(3) are involved in CCL8 induction during the inflammatory process against bacterial infection. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  8. Requirement of Osteopontin in the migration and protection against Taxol-induced apoptosis via the ATX-LPA axis in SGC7901 cells

    Directory of Open Access Journals (Sweden)

    Huang Zuhu

    2011-03-01

    Full Text Available Abstract Background Autotaxin (ATX possesses lysophospholipase D (lyso PLD activity, which converts lysophosphatidylcholine (LPC into lysophosphatidic acid (LPA. The ATX-LPA signaling axis has been implicated in angiogenesis, chronic inflammation and tumor progression. Osteopontin (OPN is an important chemokine involved in the survival, proliferation, migration, invasion and metastasis of gastric cancer cells. The focus of the present study was to investigate the relationship between the ATX-LPA axis and OPN. Results In comparison with non-treated cells, we found that the ATX-LPA axis up-regulated OPN expression by 1.92-fold in protein levels and 1.3-fold in mRNA levels. The ATX-LPA axis activates LPA2, Akt, ERK and ELK-1 and also protects SGC7901 cells from apoptosis induced by Taxol treatment. Conclusions This study provides the first evidence that expression of OPN induced by ATX-LPA axis is mediated by the activation of Akt and MAPK/ERK pathways through the LPA2 receptor. In addition, OPN is required for the protective effects of ATX-LPA against Taxol-induced apoptosis and ATX-LPA-induced migration of SGC7901 cells.

  9. Structural basis of substrate discrimination and integrin binding by autotaxin

    Energy Technology Data Exchange (ETDEWEB)

    Hausmann, Jens; Kamtekar, Satwik; Christodoulou, Evangelos; Day, Jacqueline E.; Wu, Tao; Fulkerson, Zachary; Albers, Harald M.H.G.; van Meeteren, Laurens A.; Houben, Anna J.S.; van Zeijl, Leonie; Jansen, Silvia; Andries, Maria; Hall, Troii; Pegg, Lyle E.; Benson, Timothy E.; Kasiem, Mobien; Harlos, Karl; Vander Kooi, Craig W.; Smyth, Susan S.; Ovaa, Huib; Bollen, Mathieu; Morris, Andrew J.; Moolenaar, Wouter H.; Perrakis, Anastassis (Pfizer); (Leuven); (Oxford); (NCI-Netherlands); (Kentucky)

    2013-09-25

    Autotaxin (ATX, also known as ectonucleotide pyrophosphatase/phosphodiesterase-2, ENPP2) is a secreted lysophospholipase D that generates the lipid mediator lysophosphatidic acid (LPA), a mitogen and chemoattractant for many cell types. ATX-LPA signaling is involved in various pathologies including tumor progression and inflammation. However, the molecular basis of substrate recognition and catalysis by ATX and the mechanism by which it interacts with target cells are unclear. Here, we present the crystal structure of ATX, alone and in complex with a small-molecule inhibitor. We have identified a hydrophobic lipid-binding pocket and mapped key residues for catalysis and selection between nucleotide and phospholipid substrates. We have shown that ATX interacts with cell-surface integrins through its N-terminal somatomedin B-like domains, using an atypical mechanism. Our results define determinants of substrate discrimination by the ENPP family, suggest how ATX promotes localized LPA signaling and suggest new approaches for targeting ATX with small-molecule therapeutic agents.

  10. Exosomes bind to autotaxin and act as a physiological delivery mechanism to stimulate LPA receptor signalling in cells

    Science.gov (United States)

    Jethwa, Susanna A.; Leah, Emma J.; Zhang, Qifeng; Bright, Nicholas A.; Oxley, David; Bootman, Martin D.; Rudge, Simon A.

    2016-01-01

    ABSTRACT Autotaxin (ATX; also known as ENPP2), the lysophospholipase responsible for generating the lipid receptor agonist lysophosphatidic acid (LPA), is a secreted enzyme. Here we show that, once secreted, ATX can bind to the surface of cell-secreted exosomes. Exosome-bound ATX is catalytically active and carries generated LPA. Once bound to a cell, through specific integrin interactions, ATX releases the LPA to activate cell surface G-protein-coupled receptors of LPA; inhibition of signalling by the receptor antagonist Ki1642 suggests that these receptors are LPAR1 and LPAR3. The binding stimulates downstream signalling, including phosphorylation of AKT and mitogen-activated protein kinases, the release of intracellular stored Ca2+ and cell migration. We propose that exosomal binding of LPA-loaded ATX provides a means of efficiently delivering the lipid agonist to cell surface receptors to promote signalling. We further propose that this is a means by which ATX–LPA signalling operates physiologically. PMID:27557622

  11. Exocrine pancreatic carcinogenesis and autotaxin expression.

    Directory of Open Access Journals (Sweden)

    Sandeep Kadekar

    Full Text Available Exocrine pancreatic cancer is an aggressive disease with an exceptionally high mortality rate. Genetic analysis suggests a causative role for environmental factors, but consistent epidemiological support is scarce and no biomarkers for monitoring the effects of chemical pancreatic carcinogens are available. With the objective to identify common traits for chemicals inducing pancreatic tumors we studied the National Toxicology Program (NTP bioassay database. We found that male rats were affected more often than female rats and identified eight chemicals that induced exocrine pancreatic tumors in males only. For a hypothesis generating process we used a text mining tool to analyse published literature for suggested mode of actions (MOA. The resulting MOA analysis suggested inflammatory responses as common feature. In cell studies we found that all the chemicals increased protein levels of the inflammatory protein autotaxin (ATX in Panc-1, MIA PaCa-2 or Capan-2 cells. Induction of MMP-9 and increased invasive migration were also frequent effects, consistent with ATX activation. Testosterone has previously been implicated in pancreatic carcinogenesis and we found that it increased ATX levels. Our data show that ATX is a target for chemicals inducing pancreatic tumors in rats. Several lines of evidence implicate ATX and its product lysophosphatidic acid in human pancreatic cancer. Mechanisms of action may include stimulated invasive growth and metastasis. ATX may interact with hormones or onco- or suppressor-genes often deregulated in exocrine pancreatic cancer. Our data suggest that ATX is a target for chemicals promoting pancreatic tumor development.

  12. Immunohistochemical detection of autotaxin (ATX)/lysophospholipase D (lysoPLD) in submucosal invasive colorectal cancer.

    Science.gov (United States)

    Kazama, Shinsuke; Kitayama, Joji; Aoki, Junken; Mori, Ken; Nagawa, Hirokazu

    2011-12-01

    Autotaxin (ATX) is molecularly identical to lysophospholipase D (lysoPLD) and is a main enzyme producing lysophosphatidic acid (LPA), which mediates a broad range of cellular responses including stimulation of cell motility. Using immunohistochemical staining, we examined the expression of ATX/lysoPLD in 98 cases of early colorectal cancer with submucosal invasion. ATX/lysoPLD was highly expressed in infiltrating cells in tumor tissue in the submucosal layer, which were characterized as mast cells. The number of ATX/lysoPLD-positive cells was significantly greater in tumors with a macroscopically depressed lesion than in tumors without depression. The density of ATX/lysoPLD-positive cells tended to have a positive correlation with microvessel vascular density (MVD), while it was not correlated with vessel invasion and nodal metastases as well as lymphovascular vessel density (LVD). Our results suggest that local production of LPA through ATX/lysoPLD may weakly correlate with formation of a depressive lesion and tumor angiogenesis in the early stage of colorectal cancer.

  13. Serum Autotaxin is a Marker of the Severity of Liver Injury and Overall Survival in Patients with Cholestatic Liver Diseases

    Science.gov (United States)

    Wunsch, Ewa; Krawczyk, Marcin; Milkiewicz, Malgorzata; Trottier, Jocelyn; Barbier, Olivier; Neurath, Markus F.; Lammert, Frank; Kremer, Andreas E.; Milkiewicz, Piotr

    2016-01-01

    Autotaxin (ATX) is involved in the synthesis of lysophosphatidic acid. Both have recently been linked to cholestatic pruritus and liver injury. We aimed to investigate whether ATX is an indicator of cholestatic liver injury, health-related quality of life (HRQoL) and prognosis based on a group of 233 patients, 118 with primary biliary cholangitis (PBC) and 115 with primary sclerosing cholangitis (PSC). Patients were followed for 1–60 months, cumulative survival rates were calculated. ATX activity was significantly higher in both groups than in the 103 controls, particularly in patients with cirrhosis and in patients with longer disease duration. Ursodeoxycholic acid (UDCA) non-responders with PBC exhibited increased ATX activity. ATX activity was correlated with liver biochemistry, MELD, Mayo Risk scores and was associated with worse disease-specific HRQoL aspects. In both groups, Cox model analysis indicated that ATX was a negative predictor of survival. Increased ATX levels were associated with a 4-fold higher risk of death/liver transplantation in patients with PBC and a 2.6-fold higher risk in patients with PSC. We conclude that in patients with cholestatic conditions, ATX is not only associated with pruritus but also indicates impairment of other HRQoL aspects, liver dysfunction, and can serve as a predictor of survival. PMID:27506882

  14. Autotaxin and Endotoxin-Induced Acute Lung Injury

    Science.gov (United States)

    Oikonomou, Nikos; Katsifa, Aggeliki; Prestwich, Glenn D.; Kaffe, Eleanna; Aidinis, Vassilis

    2015-01-01

    Acute Lung Injury (ALI) is a life-threatening, diffuse heterogeneous lung injury characterized by acute onset, pulmonary edema and respiratory failure. Lipopolysaccharide (LPS) is a common cause of both direct and indirect lung injury and when administered to a mouse induces a lung phenotype exhibiting some of the clinical characteristics of human ALI. Here, we report that LPS inhalation in mice results in increased bronchoalveolar lavage fluid (BALF) levels of Autotaxin (ATX, Enpp2), a lysophospholipase D largely responsible for the conversion of lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA) in biological fluids and chronically inflamed sites. In agreement, gradual increases were also detected in BALF LPA levels, following inflammation and pulmonary edema. However, genetic or pharmacologic targeting of ATX had minor effects in ALI severity, suggesting no major involvement of the ATX/LPA axis in acute inflammation. Moreover, systemic, chronic exposure to increased ATX/LPA levels was shown to predispose to and/or to promote acute inflammation and ALI unlike chronic inflammatory pathophysiological situations, further suggesting a differential involvement of the ATX/LPA axis in acute versus chronic pulmonary inflammation. PMID:26196781

  15. TCDD induces cell migration via NFATc1/ATX-signaling in MCF-7 cells.

    Science.gov (United States)

    Seifert, Anja; Rau, Steffi; Küllertz, Gerhard; Fischer, Bernd; Santos, Anne Navarrete

    2009-01-10

    Breast cancer is characterized, among others, by the concurrence of lipophilic xenobiotica such as 2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD) with hypoxic tissue conditions. This condition activates the transcription factors hypoxia inducible factor-1alpha (HIF-1alpha) and aryl hydrocarbon receptor (AhR) that are known to promote tumor progression. An interrelation between these transcription factors and nuclear factor of activated T-cells (NFAT) was implied by gene array analysis. In the present study, the interplay of the three transcription factors was studied and correlated with the migration of MCF-7 cells in response to TCDD and/or hypoxia. An AhR-activation by 10nM TCDD and HIF-1alpha activation by 5% oxygen induced activation of NFATc1. The effects were inhibited by cyclosporine A (CsA), suggesting that the activation of NFAT by AhR or HIF-1alpha signaling is calcineurin-dependent. The expression/activity of the NFAT target gene autotaxin (ATX) was increased. ATX is known to stimulate migration of tumor cells. The hydrolysis product of ATX, lysophosphatidic acid (LPA), increased the migration of MCF-7 cells under normoxia but not under hypoxia. This effect correlated with increased migration observed after TCDD treatment. Hypoxia did not promote migration of MCF-7 cells, suggesting that ATX down-stream signaling was inhibited by hypoxia. In conclusion, the TCDD-mediated activation of NFATc1 is suggested to promote cell migration via ATX/LPA-signaling.

  16. Autotaxin induces lung epithelial cell migration through lysoPLD activity-dependent and -independent pathways

    Science.gov (United States)

    Zhao, Jing; He, Donghong; Berdyshev, Evgeny; Zhong, Mintao; Salgia, Ravi; Morris, Andrew J.; Smyth, Susan S.; Natarajan, Viswanathan; Zhao, Yutong

    2013-01-01

    SYNOPSIS Lung cell migration is a crucial step for re-epithelialization that in turn is essential for remodeling and repair after lung injury. We hypothesize that secreted autotaxin (ATX), which exhibits lysophospholipase D (lysoPLD) activity, stimulates lung epithelial cell migration through lysophosphatidic acid (LPA) generation-dependent and -independent pathways. Release of endogenous ATX protein and activity was detected in lung epithelial cell culture medium. ATX with V5 tag (ATX-V5) overexpressed conditional medium had higher LPA levels compared to control medium and stimulated cell migration through Gαi-coupled LPA receptors, cytoskeleton rearrangement, phosphorylation of PKCδ and cortactin at the leading edge of migrating cells. Inhibition of PKCδ attenuated ATX-V5 overexpressed conditional medium-mediated phosphorylation of cortactin. In addition, a recombinant ATX mutant, lacking lysoPLD activity, or heat-inactived ATX also induced lung epithelial cell migration. Extracelluar ATX bound to LPA receptor and integrin β4 complex on A549 cell surface. Finally, intratracheal administration of lipopolysaccharide into mouse airway induced ATX release and LPA production in bronchoalveolar lavage fluid. These results suggested a significant role for ATX in lung epithelial cell migration and remodeling through its ability to induce LPA production-mediated phosphorylation of PKCδ and cortactin. In addition we also demonstrated assocation of ATX with epithelial cell surface LPA receptor and integrin β4. PMID:21696367

  17. Requirement of Osteopontin in the migration and protection against Taxol-induced apoptosis via the ATX-LPA axis in SGC7901 cells.

    Science.gov (United States)

    Zhang, Rihua; Wang, Jing; Ma, Shijie; Huang, Zuhu; Zhang, Guoxin

    2011-03-16

    Autotaxin (ATX) possesses lysophospholipase D (lyso PLD) activity, which converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA). The ATX-LPA signaling axis has been implicated in angiogenesis, chronic inflammation and tumor progression. Osteopontin (OPN) is an important chemokine involved in the survival, proliferation, migration, invasion and metastasis of gastric cancer cells. The focus of the present study was to investigate the relationship between the ATX-LPA axis and OPN. In comparison with non-treated cells, we found that the ATX-LPA axis up-regulated OPN expression by 1.92-fold in protein levels and 1.3-fold in mRNA levels. The ATX-LPA axis activates LPA2, Akt, ERK and ELK-1 and also protects SGC7901 cells from apoptosis induced by Taxol treatment. This study provides the first evidence that expression of OPN induced by ATX-LPA axis is mediated by the activation of Akt and MAPK/ERK pathways through the LPA2 receptor. In addition, OPN is required for the protective effects of ATX-LPA against Taxol-induced apoptosis and ATX-LPA-induced migration of SGC7901 cells.

  18. Drosophila homologue of Diaphanous 1 (DIAPH1) controls the metastatic potential of colon cancer cells by regulating microtubule-dependent adhesion.

    Science.gov (United States)

    Lin, Yuan-Na; Bhuwania, Ridhirama; Gromova, Kira; Failla, Antonio Virgilio; Lange, Tobias; Riecken, Kristoffer; Linder, Stefan; Kneussel, Matthias; Izbicki, Jakob R; Windhorst, Sabine

    2015-07-30

    Drosophila homologue of Diaphanous 1 (DIAPH1) regulates actin polymerization and microtubule (MT) stabilization upon stimulation with lysophosphatidic acid (LPA). Recently, we showed strongly reduced lung metastasis of DIAPH1-depleted colon cancer cells but we found accumulations of DIAPH1-depleted cells in bone marrow. Here, we analyzed possible organ- or tissue-specific metastasis of DIAPH1-depleted HCT-116 cells. Our data confirmed that depletion of DIAPH1 strongly inhibited lung metastasis and revealed that, in contrast to control cells, DIAPH1-depleted cells did not form metastases in further organs. Detailed mechanistic analysis on cells that were not stimulated with LPA to activate the cytoskeleton-modulating activity of DIAPH1, revealed that even under basal conditions DIAPH1 was essential for cellular adhesion to collagen. In non-stimulated cells DIAPH1 did not control actin dynamics but, interestingly, was essential for stabilization of microtubules (MTs). Additionally, DIAPH1 controlled directed vesicle trafficking and with this, local clustering of the adhesion protein integrin-β1 at the plasma membrane. Therefore, we conclude that under non-stimulating conditions DIAPH1 controls cellular adhesion by stabilizing MTs required for local clustering of integrin-β1 at the plasma membrane. Thus, blockade of DIAPH1-tubulin interaction may be a promising approach to inhibit one of the earliest steps in the metastatic cascade of colon cancer.

  19. The regulatory effects of low-dose ionizing radiation on Ikaros-autotaxin interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hana; Cho, Seong Jun; Kim, Sung Jin; Nam, Seon Young; Yang, Kwang Hee [KHNP Radiation Health Institute, Korea Hydro and Nuclear Power Co, Seoul (Korea, Republic of)

    2016-11-15

    Ikaros, a transcription factor containing zinc-finger motif, has known as a critical regulator of hematopoiesis in immune system. Ikaros protein modulates the transcription of target genes via binding to the regulatory elements of the genes promoters. However the regulatory function of Ikaros in other organelle except nuclear remains to be determined. This study explored radiation-induced modulatory function of Ikaros in cytoplasm. The results showed that Ikaros protein lost its DNA binding ability after LDIR (low-dose ionizing radiation) exposure. Cell fractionation and Western blot analysis showed that Ikaros protein was translocated into cytoplasm from nuclear by LDIR. This was confirmed by immunofluorescence assay. We identified Autotaxin as a novel protein which potentially interacts with Ikaros through in vitro protein-binding screening. Co-immunoprecipitation assay revealed that Ikaros and Autotaxin are able to bind each other. Autotaxin is a crucial enzyme generating lysophosphatidic acid (LPA), a phospholipid mediator, which has potential regulatory effects on immune cell growth and motility. Our results indicate that LDIR potentially regulates immune system via protein-protein interaction of Ikaros and Autotaxin.

  20. Fc-receptor-mediated phagocytosis is regulated by mechanical properties of the target

    Science.gov (United States)

    Beningo, Karen A.; Wang, Yu-li

    2002-01-01

    Phagocytosis is an actin-based process used by macrophages to clear particles greater than 0.5 microm in diameter. In addition to its role in immunological responses, phagocytosis is also necessary for tissue remodeling and repair. To prevent catastrophic autoimmune reactions, phagocytosis must be tightly regulated. It is commonly assumed that the recognition/selection of phagocytic targets is based solely upon receptor-ligand binding. Here we report an important new criterion, that mechanical parameters of the target can dramatically affect the efficiency of phagocytosis. When presented with particles of identical chemical properties but different rigidity, macrophages showed a strong preference to engulf rigid objects. Furthermore, phagocytosis of soft particles can be stimulated with the microinjection of constitutively active Rac1 but not RhoA, and with lysophosphatidic acid, an agent known to activate the small GTP-binding proteins of the Rho family. These data suggest a Rac1-dependent mechanosensory mechanism for phagocytosis, which probably plays an important role in a number of physiological and pathological processes from embryonic development to autoimmune diseases.

  1. Ecdysone and insulin signaling play essential roles in readjusting the altered body size caused by the dGPAT4 mutation in Drosophila.

    Science.gov (United States)

    Yan, Yan; Wang, Hao; Chen, Hanqing; Lindström-Battle, Anya; Jiao, Renjie

    2015-09-20

    Body size is one of the features that distinguish one species from another in the biological world. Animals have developed mechanisms to control their body size during normal development. However, how animals cope with genetic alterations and/or environmental stresses to develop into normal-sized adults remain poorly understood. The ability of the animals to develop into a normal-sized adult after the challenges of genetic alterations and/or environmental stresses reveals a robustness of body size control. Here we show that the mutation of dGPAT4, a de novo synthase of lysophosphatidic acid, is a genetic alteration that triggers such a robust response of the animals to body size challenges in Drosophila. Loss of dGPAT4 leads to a severe delay of development, slow growth and resultant small-sized animals during the larval stages, but results in normal-sized adult flies. The robust body size adjustment of the dGPAT4 mutant is likely achieved by corresponding changes in ecdysone and insulin signaling, which is also manifested by compromised food intake. Thus, we propose that a strategy has been evolved by the animals to reach final body size when challenged by genetic alterations, which requires the coordinated ecdysone and insulin signaling. Copyright © 2015 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  2. In silico structural determination of GPAT enzyme from Ostreococcus lucimarinus for biotechnological application of microalgal biofuel production

    International Nuclear Information System (INIS)

    Baral, Maitree; Misra, Namrata; Panda, Prasanna Kumar; Thirunavoukkarasu, Manakkannan

    2012-01-01

    Glycerol-3-phosphate acyltransferase (GPAT) is an enzyme in the triacylglycerol (TAG) biosynthetic pathway that catalyses the conversion of glycerol-3-phosphate to lysophosphatidic acid. Targeting key enzymes involved in TAG pathway is considered to be a powerful strategy for augmented lipid accumulation in microorganisms. In the present study three-dimensional structure of the marine microalgae, Ostreococcus lucimarinus GPAT protein was developed based on the crystal structure of Cucurbita moschata GPAT protein. Besides, several structure validation tools were employed to confirm the reliability of the developed model. The predicted and validated model reveals the tertiary structure of GPAT monomer comprising of two domains, the smaller domain I, which folds into a four helix bundle, and the larger domain II, which is constructed from alternating α/β secondary structural elements that give rise to 9-stranded β sheet flanked by 11α helices. Critical structural analysis of the developed model reveals the presence of H(X) 4D motif; the latter being, a consensus sequence conserved amongst many glycerolipid acyltransferase. The detected cluster of positively charged residues H189, K243, H244, R285 and R287 in the model could be conjectured to be important in glycerol-3-phosphate recognition. The structural insight obtained from this in silico study may provide useful clues to further advanced biotechnological studies of strategic site-specific genetic and metabolic engineering of microalgae for enhanced biofuel production.

  3. Autotaxin and Endotoxin-Induced Acute Lung Injury.

    Directory of Open Access Journals (Sweden)

    Marios-Angelos Mouratis

    Full Text Available Acute Lung Injury (ALI is a life-threatening, diffuse heterogeneous lung injury characterized by acute onset, pulmonary edema and respiratory failure. Lipopolysaccharide (LPS is a common cause of both direct and indirect lung injury and when administered to a mouse induces a lung phenotype exhibiting some of the clinical characteristics of human ALI. Here, we report that LPS inhalation in mice results in increased bronchoalveolar lavage fluid (BALF levels of Autotaxin (ATX, Enpp2, a lysophospholipase D largely responsible for the conversion of lysophosphatidylcholine (LPC to lysophosphatidic acid (LPA in biological fluids and chronically inflamed sites. In agreement, gradual increases were also detected in BALF LPA levels, following inflammation and pulmonary edema. However, genetic or pharmacologic targeting of ATX had minor effects in ALI severity, suggesting no major involvement of the ATX/LPA axis in acute inflammation. Moreover, systemic, chronic exposure to increased ATX/LPA levels was shown to predispose to and/or to promote acute inflammation and ALI unlike chronic inflammatory pathophysiological situations, further suggesting a differential involvement of the ATX/LPA axis in acute versus chronic pulmonary inflammation.

  4. Jaundice associated pruritis: a review of pathophysiology and treatment.

    Science.gov (United States)

    Bassari, Ramez; Koea, Jonathan B

    2015-02-07

    To review the underlying pathophysiology and currently available treatments for pruritis associated with jaundice. English language literature was reviewed using MEDLINE, PubMed, EMBASE and clinicaltrials.gov for papers and trails addressing the pathophysiology and potential treatments for pruritis associated with jaundice. Recent advances in the understanding of the peripheral anatomy of itch transmission have defined a histamine stimulated pathway and a cowhage stimulated pathway with sensation conveyed centrally via the contralateral spinothalamic tract. Centrally, cowhage and histamine stimulated neurons terminate widely within the thalamus and sensorimotor cortex. The causative factors for itch in jaundice have not been clarified although endogenous opioids, serotonin, steroid and lysophosphatidic acid all play a role. Current guidelines for the treatment of itching in jaundice recommend initial management with biliary drainage where possible and medical management with ursodeoxycholic acid, followed by cholestyramine, rifampicin, naltrexone and sertraline. Other than biliary drainage no single treatment has proved universally effective. Pruritis associated with jaundice is a common but poorly understood condition for which biliary drainage is the most effective therapy. Pharmacological therapy has advanced but remains variably effective.

  5. Lysophospholipid receptors are differentially expressed in rat terminal Schwann cells, as revealed by a single cell rt-PCR and in situ hybridization.

    Science.gov (United States)

    Kobashi, Hiroaki; Yaoi, Takeshi; Oda, Ryo; Okajima, Seiichiro; Fujiwara, Hiroyoshi; Kubo, Toshikazu; Fushiki, Shinji

    2006-04-22

    Terminal Schwann cells (TSCs) that cover motor neuron terminals, are known to play an important role in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, the molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. By using our previously reported method of selectively and efficiently collecting TSCs, we have analyzed the difference in expression patterns of lysophospholipid (LPL) receptor genes (LPA1, LPA2, LPA3, S1P1, S1P2, S1P3, S1P4, and S1P5) between TSCs and myelinating Schwann cells (MSCs). LPL, which includes lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), is the bioactive lipid that induces a myriad of cellular responses through specific members of G-protein coupled receptors for LPA. It turned out that LPA3 was expressed only in TSCs, whereas S1P1 was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA1, S1P2, S1P3, S1P4, were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression.

  6. Cholesterol inhibits entotic cell-in-cell formation and actomyosin contraction.

    Science.gov (United States)

    Ruan, Banzhan; Zhang, Bo; Chen, Ang; Yuan, Long; Liang, Jianqing; Wang, Manna; Zhang, Zhengrong; Fan, Jie; Yu, Xiaochen; Zhang, Xin; Niu, Zubiao; Zheng, You; Gu, Songzhi; Liu, Xiaoqing; Du, Hongli; Wang, Jufang; Hu, Xianwen; Gao, Lihua; Chen, Zhaolie; Huang, Hongyan; Wang, Xiaoning; Sun, Qiang

    2018-01-01

    Cell-in-cell structure is prevalent in human cancer, and associated with several specific pathophysiological phenomena. Although cell membrane adhesion molecules were found critical for cell-in-cell formation, the roles of other membrane components, such as lipids, remain to be explored. In this study, we attempted to investigate the effects of cholesterol and phospholipids on the formation of cell-in-cell structures by utilizing liposome as a vector. We found that Lipofectamine-2000, the reagent commonly used for routine transfection, could significantly reduce entotic cell-in-cell formation in a cell-specific manner, which is correlated with suppressed actomyosin contraction as indicated by reduced β-actin expression and myosin light chain phosphorylation. The influence on cell-in-cell formation was likely dictated by specific liposome components as some liposomes affected cell-in-cell formation while some others didn't. Screening on a limited number of lipids, the major components of liposome, identified phosphatidylethanolamine (PE), stearamide (SA), lysophosphatidic acid (LPA) and cholesterol (CHOL) as the inhibitors of cell-in-cell formation. Importantly, cholesterol treatment significantly inhibited myosin light chain phosphorylation, which resembles the effect of Lipofectamine-2000, suggesting cholesterol might be partially responsible for liposomes' effects on cell-in-cell formation. Together, our findings supporting a role of membrane lipids and cholesterol in cell-in-cell formation probably via regulating actomyosin contraction. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Biosynthesis of triacylglycerols containing very long chain monounsaturated acyl moieties in developing seeds

    International Nuclear Information System (INIS)

    Fehling, E.; Murphy, D.J.; Mukherjee, K.D.

    1990-01-01

    Particulate (15,000g) fractions from developing seeds of honesty (Lunaria annua L.) and mustard (Sinapis alba L.) synthesize radioactive very long chain monounsaturated fatty acids (gadoleic, erucic, and nervonic) from [1- 14 C]oleoyl-CoA and malonyl-CoA or from oleoyl-CoA and [2- 14 C]malonyl-CoA. The very long chain monounsaturated fatty acids are rapidly channeled to triacylglycerols and other acyl lipids without intermediate accumulation of their CoA thioesters. When [1- 14 C]oleoyl-CoA is used as the radioactive substrate, phosphatidylcholines and other phospholipids are most extensively radiolabeled by oleoyl moieties rather than by very long chain monounsaturated acyl moieties. When [2- 14 C]malonyl-CoA is used as the radioactive substrate, no radioactive oleic acid is formed and the newly synthesized very long chain monounsaturated fatty acids are extensively incorporated into phosphatidylcholines and other phospholipids as well as triacylglycerols. The pattern of labeling of the key intermediates of the Kennedy pathway, e.g. lysophosphatidic acids, phosphatidic acids, and diacylglycerols by the newly synthesized very long chain monounsaturated fatty acids is consistent with the operation of this pathway in the biosynthesis of triacylglycerols

  8. Metabolic engineering of medium-chain fatty acid biosynthesis in Nicotiana benthamiana plant leaf lipids

    Science.gov (United States)

    Reynolds, Kyle B.; Taylor, Matthew C.; Zhou, Xue-Rong; Vanhercke, Thomas; Wood, Craig C.; Blanchard, Christopher L.; Singh, Surinder P.; Petrie, James R.

    2015-01-01

    Various research groups are investigating the production of oil in non-seed biomass such as leaves. Recently, high levels of oil accumulation have been achieved in plant biomass using a combination of biotechnological approaches which also resulted in significant changes to the fatty acid composition of the leaf oil. In this study, we were interested to determine whether medium-chain fatty acids (MCFA) could be accumulated in leaf oil. MCFA are an ideal feedstock for biodiesel and a range of oleochemical products including lubricants, coatings, and detergents. In this study, we explore the synthesis, accumulation, and glycerolipid head-group distribution of MCFA in leaves of Nicotiana benthamiana after transient transgenic expression of C12:0-, C14:0-, and C16:0-ACP thioesterase genes. We demonstrate that the production of these MCFA in leaf is increased by the co-expression of the WRINKLED1 (WRI1) transcription factor, with the lysophosphatidic acid acyltransferase (LPAAT) from Cocos nucifera being required for the assembly of tri-MCFA TAG species. We also demonstrate that the newly-produced MCFA are incorporated into the triacylglycerol of leaves in which WRI1 + diacylglycerol acyltransferase1 (DGAT1) genes are co-expressed for increased oil accumulation. PMID:25852716

  9. TrkB-T1 regulates the RhoA signaling and actin cytoskeleton in glioma cells

    International Nuclear Information System (INIS)

    Ohira, Koji; Homma, Koichi J.; Hirai, Hirohisa; Nakamura, Shun; Hayashi, Motoharu

    2006-01-01

    Recently, the truncated TrkB receptor, T1, has been reported to be involved in the control of cell morphology via the regulation of Rho proteins, through which T1 binds Rho guanine nucleotide dissociation inhibitor (Rho GDI) 1 and dissociates it in a brain-derived neurotrophic factor (BDNF)-dependent manner. However, it is unclear whether T1 signaling regulates the downstream of Rho signaling and the actin cytoskeleton. In this study, we investigated this question using C6 rat glioma cells, which express T1 endogenously. Rho GDI1 was dissociated from T1 in a BDNF-dependent manner, which also causes decreases in the activities of Rho-signaling molecules such as RhoA, Rho-associated kinase, p21-activated kinase, and extracellular-signal regulated kinase1/2. Moreover, BDNF treatment resulted in the disappearance of stress fibers in the cells treated with lysophosphatidic acid, an activator of RhoA, and in morphological changes in cells. Furthermore, a competitive assay with cyan fluorescent protein fusion proteins of T1-specific sequences reduced the effects of BDNF. These results suggest that T1 regulates the Rho-signaling pathways and the actin cytoskeleton

  10. Geranylgeranylacetone inhibits ovarian cancer progression in vitro and in vivo

    International Nuclear Information System (INIS)

    Hashimoto, Kae; Morishige, Ken-ichirou; Sawada, Kenjiro; Ogata, Seiji; Tahara, Masahiro; Shimizu, Shoko; Sakata, Masahiro; Tasaka, Keiichi; Kimura, Tadashi

    2007-01-01

    Geranylgeranylacetone (GGA), an isoprenoid compound, is an anti-ulcer drug developed in Japan. In our previous study, GGA was shown to inhibit ovarian cancer invasion by attenuating Rho activation [K. Hashimoto, K. Morishige, K. Sawada, M. Tahara, S. Shimizu, M. Sakata, K. Tasaka, Y. Murata, Geranylgeranylacetone inhibits lysophosphatidic acid-induced invasion of human ovarian carcinoma cells in vitro. Cancer 103 (2005) 1529-1536.]. In the present study, GGA treatment inhibited ovarian cancer progression in vitro and suppressed the tumor growth and ascites in the in vivo ovarian cancer model. In vitro analysis, treatment of cancer cells by GGA resulted in the inhibition of cancer cell proliferation, the inactivation of Ras, and the suppression of tyrosine phosphorylation of mitogen-activated protein kinase (MAPK). In conclusion, this is the first report that GGA inhibited ovarian cancer progression and the anti-tumor effect by GGA is, at least in part, derived not only from the suppression of Rho activation but also Ras-MAPK activation

  11. Decreased peritoneal ovarian cancer growth in mice lacking expression of lipid phosphate phosphohydrolase 1.

    Directory of Open Access Journals (Sweden)

    John Nakayama

    Full Text Available Lysophosphatidic acid (LPA is a bioactive lipid that enhances ovarian cancer cell proliferation, migration and invasion in vitro and stimulates peritoneal metastasis in vivo. LPA is generated through the action of autotaxin or phospholipases, and degradation begins with lipid phosphate phosphohydrolase (LPP-dependent removal of the phosphate. While the effects of LPA on ovarian cancer progression are clear, the effects of LPA metabolism within the tumor microenvironment on peritoneal metastasis have not been reported. We examined the contribution of lipid phosphatase activity to ovarian cancer peritoneal metastasis using mice deficient in LPP1 expression. Homozygous deletion of LPP1 (LPP1 KO results in elevated levels and decreased turnover of LPA in vivo. Within 2 weeks of intraperitoneal injection of syngeneic mouse ovarian cancer cells, we observed enhanced tumor seeding in the LPP1 KO mice compared to wild type. However, tumor growth plateaued in the LPP1 KO mice by 3 weeks while tumors continued to grow in wild type mice. The decreased tumor burden was accompanied by increased apoptosis and no change in proliferation or angiogenesis. Tumor growth was restored and apoptosis reversed with exogenous administration of LPA. Together, these observations demonstrate that the elevated levels of LPA per se in LPP1 KO mice do not inhibit tumor growth. Rather, the data support the notion that either elevated LPA concentration or altered LPA metabolism affects other growth-promoting contributions of the tumor microenvironment.

  12. Imaging dynamic redox changes in mammalian cells with green fluorescent protein indicators.

    Science.gov (United States)

    Dooley, Colette T; Dore, Timothy M; Hanson, George T; Jackson, W Coyt; Remington, S James; Tsien, Roger Y

    2004-05-21

    Changes in the redox equilibrium of cells influence a host of cell functions. Alterations in the redox equilibrium are precipitated by changing either the glutathione/glutathione-disulfide ratio (GSH/GSSG) and/or the reduced/oxidized thioredoxin ratio. Redox-sensitive green fluorescent proteins (GFP) allow real time visualization of the oxidation state of the indicator. Ratios of fluorescence from excitation at 400 and 490 nm indicate the extent of oxidation and thus the redox potential while canceling out the amount of indicator and the absolute optical sensitivity. Because the indicator is genetically encoded, it can be targeted to specific proteins or organelles of interest and expressed in a wide variety of cells and organisms. We evaluated roGFP1 (GFP with mutations C48S, S147C, and Q204C) and roGFP2 (the same plus S65T) with physiologically or toxicologically relevant oxidants both in vitro and in living mammalian cells. Furthermore, we investigated the response of the redox probes under physiological redox changes during superoxide bursts in macrophage cells, hyperoxic and hypoxic conditions, and in responses to H(2)O(2)-stimulating agents, e.g. epidermal growth factor and lysophosphatidic acid.

  13. Non-invasive imaging of tumors by monitoring autotaxin activity using an enzyme-activated near-infrared fluorogenic substrate.

    Directory of Open Access Journals (Sweden)

    Damian Madan

    Full Text Available Autotaxin (ATX, an autocrine motility factor that is highly upregulated in metastatic cancer, is a lysophospholipase D enzyme that produces the lipid second messenger lysophosphatidic acid (LPA from lysophosphatidylcholine (LPC. Dysregulation of the lysolipid signaling pathway is central to the pathophysiology of numerous cancers, idiopathic pulmonary fibrosis, rheumatoid arthritis, and other inflammatory diseases. Consequently, the ATX/LPA pathway has emerged as an important source of biomarkers and therapeutic targets. Herein we describe development and validation of a fluorogenic analog of LPC (AR-2 that enables visualization of ATX activity in vivo. AR-2 exhibits minimal fluorescence until it is activated by ATX, which substantially increases fluorescence in the near-infrared (NIR region, the optimal spectral window for in vivo imaging. In mice with orthotopic ATX-expressing breast cancer tumors, ATX activated AR-2 fluorescence. Administration of AR-2 to tumor-bearing mice showed high fluorescence in the tumor and low fluorescence in most healthy tissues with tumor fluorescence correlated with ATX levels. Pretreatment of mice with an ATX inhibitor selectively decreased fluorescence in the tumor. Together these data suggest that fluorescence directly correlates with ATX activity and its tissue expression. The data show that AR-2 is a non-invasive and selective tool that enables visualization and quantitation of ATX-expressing tumors and monitoring ATX activity in vivo.

  14. LPA receptor activity is basal specific and coincident with early pregnancy and involution during mammary gland postnatal development

    Science.gov (United States)

    Acosta, Deanna; Bagchi, Susmita; Broin, Pilib Ó; Hollern, Daniel; Racedo, Silvia E.; Morrow, Bernice; Sellers, Rani S.; Greally, John M.; Golden, Aaron; Andrechek, Eran; Wood, Teresa; Montagna, Cristina

    2016-01-01

    During pregnancy, luminal and basal epithelial cells of the adult mammary gland proliferate and differentiate resulting in remodeling of the adult gland. While pathways that control this process have been characterized in the gland as a whole, the contribution of specific cell subtypes, in particular the basal compartment, remains largely unknown. Basal cells provide structural and contractile support, however they also orchestrate the communication between the stroma and the luminal compartment at all developmental stages. Using RNA-seq, we show that basal cells are extraordinarily transcriptionally dynamic throughout pregnancy when compared to luminal cells. We identified gene expression changes that define specific basal functions acquired during development that led to the identification of novel markers. Enrichment analysis of gene sets from 24 mouse models for breast cancer pinpoint to a potential new function for insulin-like growth factor 1 (Igf1r) in the basal epithelium during lactogenesis. We establish that β-catenin signaling is activated in basal cells during early pregnancy, and demonstrate that this activity is mediated by lysophosphatidic acid receptor 3 (Lpar3). These findings identify novel pathways active during functional maturation of the adult mammary gland. PMID:27808166

  15. Proteomic screening of human targets of viral microRNAs reveals functions associated with immune evasion and angiogenesis.

    Directory of Open Access Journals (Sweden)

    Amelia M Gallaher

    Full Text Available Kaposi's sarcoma (KS is caused by infection with Kaposi's sarcoma-associated herpesvirus (KSHV. The virus expresses unique microRNAs (miRNAs, but the targets and functions of these miRNAs are not completely understood. In order to identify human targets of viral miRNAs, we measured protein expression changes caused by multiple KSHV miRNAs using pulsed stable labeling with amino acids in cell culture (pSILAC in primary endothelial cells. This led to the identification of multiple human genes that are repressed at the protein level, but not at the miRNA level. Further analysis also identified that KSHV miRNAs can modulate activity or expression of upstream regulatory factors, resulting in suppressed activation of a protein involved in leukocyte recruitment (ICAM1 following lysophosphatidic acid treatment, as well as up-regulation of a pro-angiogenic protein (HIF1α, and up-regulation of a protein involved in stimulating angiogenesis (HMOX1. This study aids in our understanding of miRNA mechanisms of repression and miRNA contributions to viral pathogenesis.

  16. Fucoxanthin Suppresses Lipid Accumulation and ROS Production During Differentiation in 3T3-L1 Adipocytes.

    Science.gov (United States)

    Seo, Min-Jung; Seo, Young-Jin; Pan, Cheol-Ho; Lee, Ok-Hwan; Kim, Kui-Jin; Lee, Boo-Yong

    2016-11-01

    Fucoxanthin, a pigment from the chloroplasts of marine brown algae, has a number of effects against obesity, diabetes, inflammation and cancer and provides cerebrovascular protection. In this study, we investigated the inhibitory effects of fucoxanthin on lipid accumulation and reactive oxygen species (ROS) production during adipogenesis. Treatment with fucoxanthin suppresses protein levels of the adipogenic transcription factors CCAAT/enhancer-binding protein alpha C/EBPα and peroxisome proliferator-activated receptor-γ and of their target protein, fatty acid binding protein 4. Lipogenesis-related enzymes, such as diglyceride acyltransferase 1 and lysophosphatidic acid acyltransferase-θ, were downregulated by fucoxanthin. The ROS-producing enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) and the NADPH-generating enzyme glucose-6-phosphate dehydrogenase also decreased following fucoxanthin treatment. The adipokine adiponectin and the ROS-scavenging enzymes superoxide dismutase 2, glutathione reductase and catalase were dose-dependently increased by fucoxanthin. Furthermore, lipolysis-related enzymes and superoxide dismutase 1 were slightly decreased, because of the suppression of lipid-generating factors and the cytosolic enzyme NOX4. To confirm these results, we investigated lipid accumulation and ROS production in zebrafish, where fucoxanthin suppressed lipid and triglyceride accumulation, as well as ROS production. Our data suggest that fucoxanthin inhibits lipid accumulation and ROS production by controlling adipogenic and lipogenic factors and ROS-regulating enzymes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. LPA is a chemorepellent for B16 melanoma cells: action through the cAMP-elevating LPA5 receptor.

    Directory of Open Access Journals (Sweden)

    Maikel Jongsma

    Full Text Available Lysophosphatidic acid (LPA, a lipid mediator enriched in serum, stimulates cell migration, proliferation and other functions in many cell types. LPA acts on six known G protein-coupled receptors, termed LPA(1-6, showing both overlapping and distinct signaling properties. Here we show that, unexpectedly, LPA and serum almost completely inhibit the transwell migration of B16 melanoma cells, with alkyl-LPA(18:1 being 10-fold more potent than acyl-LPA(18:1. The anti-migratory response to LPA is highly polarized and dependent on protein kinase A (PKA but not Rho kinase activity; it is associated with a rapid increase in intracellular cAMP levels and PIP3 depletion from the plasma membrane. B16 cells express LPA(2, LPA(5 and LPA(6 receptors. We show that LPA-induced chemorepulsion is mediated specifically by the alkyl-LPA-preferring LPA(5 receptor (GPR92, which raises intracellular cAMP via a noncanonical pathway. Our results define LPA(5 as an anti-migratory receptor and they implicate the cAMP-PKA pathway, along with reduced PIP3 signaling, as an effector of chemorepulsion in B16 melanoma cells.

  18. Exploratory, anxiety and spatial memory impairments are dissociated in mice lacking the LPA1 receptor

    Science.gov (United States)

    Castilla-Ortega, Estela; Sánchez-López, Jorge; Hoyo-Becerra, Carolina; Matas-Rico, Elisa; Zambrana-Infantes, Emma; Chun, Jerold; Fonseca, Fernando Rodríguez De; Pedraza, Carmen; Estivill-Torrús, Guillermo; Santin, Luis J.

    2013-01-01

    Lysophosphatidic acid (LPA) is a new, intercellular signalling molecule in the brain that has an important role in adult hippocampal plasticity. Mice lacking the LPA1 receptor exhibit motor, emotional and cognitive alterations. However, the potential relationship among these concomitant impairments was unclear. Wild-type and maLPA1-null mice were tested on the hole-board for habituation and spatial learning. MaLPA1-null mice exhibited reduced exploration in a novel context and a defective intersession habituation that also revealed increased anxiety-like behaviour throughout the hole-board testing. In regard to spatial memory, maLPA1 nulls failed to reach the controls’ performance at the end of the reference memory task. Moreover, their defective working memory on the first training day suggested a delayed acquisition of the task’s working memory rule, which is also a long term memory component. The temporal interval between trials and the task’s difficulty may explain some of the deficits found in these mice. Principal components analysis revealed that alterations found in each behavioural dimension were independent. Therefore, exploratory and emotional impairments did not account for the cognitive deficits that may be attributed to maLPA1 nulls’ hippocampal malfunction. PMID:20388543

  19. Behavioral phenotype of maLPA1-null mice: increased anxiety-like behavior and spatial memory deficits

    Science.gov (United States)

    Santin, L.J.; Bilbao, A.; Pedraza, C.; Matas-Rico, E.; López-Barroso, D.; Castilla-Ortega, E.; Sánchez-López, J.; Riquelme, R.; Varela-Nieto,