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Sample records for caviae st pyruvate

  1. Expression of Aeromonas caviae ST pyruvate dehydrogenase complex components mediate tellurite resistance in Escherichia coli

    International Nuclear Information System (INIS)

    Castro, Miguel E.; Molina, Roberto C.; Diaz, Waldo A.; Pradenas, Gonzalo A.; Vasquez, Claudio C.

    2009-01-01

    Potassium tellurite (K 2 TeO 3 ) is harmful to most organisms and specific mechanisms explaining its toxicity are not well known to date. We previously reported that the lpdA gene product of the tellurite-resistant environmental isolate Aeromonas caviae ST is involved in the reduction of tellurite to elemental tellurium. In this work, we show that expression of A. caviae ST aceE, aceF, and lpdA genes, encoding pyruvate dehydrogenase, dihydrolipoamide transacetylase, and dihydrolipoamide dehydrogenase, respectively, results in tellurite resistance and decreased levels of tellurite-induced superoxide in Escherichia coli. In addition to oxidative damage resulting from tellurite exposure, a metabolic disorder would be simultaneously established in which the pyruvate dehydrogenase complex would represent an intracellular tellurite target. These results allow us to widen our vision regarding the molecular mechanisms involved in bacterial tellurite resistance by correlating tellurite toxicity and key enzymes of aerobic metabolism.

  2. PARTICIPACION DEL COMPLEJO PIRUVATO DESHIDROGENASA DE AEROMONAS CAVIAE ST EN RESISTENCIA TELURITO DE POSTASIO (K2TEO3)

    OpenAIRE

    CASTRO RETAMAL, MIGUEL ENRIQUE; CASTRO RETAMAL, MIGUEL ENRIQUE

    2008-01-01

    El telurito de potasio (K2TeO3) es altamente tóxico para la mayoría de los seres vivos. Aunque se desconoce el mecanismo de toxicidad especifico, recientemente se ha demostrado que estaría dado, al menos en parte, por el establecimiento de un estrés oxidativo. Aeromonas caviae ST, el microorganismo utilizado en este estudio es altamente resistente a K2TeO3 y extractos crudos de esta bacteria catalizan la reducción de K2TeO3 in vitro. Se obtuvo fracciones con actividad telurito reductasa qu...

  3. Cavia porcellus

    African Journals Online (AJOL)

    SARAH

    30 sept. 2017 ... quality during early development on body weight and reproductive maturation of guinea pigs. (Cavia porcellus). Gen. Comp. Endocrin. 161,. 384-389 ;. Chauca de Zaldivar 1999 Produccion de cuyes en crianzas familiares en Peru. In : V Congreso. Latino americano de Cuyicultura, Venezuela,. Memorias…

  4. AISLADA DE Cavia porcellus

    Directory of Open Access Journals (Sweden)

    H. Jurado-Gámez

    2014-01-01

    Full Text Available Se evaluó el efectoin vitrodeLactobacillus plantarumsobreYersinia pseudotuberculosisaislada de cuyes (Cavia porcellus e identificada bioquímica y molecularmente. Se deter-minó la viabilidad deL. plantaruma diferentes pH (3.25, 4.5, 7.6 y 8.2, sales biliaresbovinas (3, 4 y 5%, bilis bovina (0.5, 1 y 2% y temperatura (38 y 45°C. Se realizóantibiograma a ambas bacterias con Cefalotina, Cefepima, Ciprofloxacina, Dicloxacilina,Enrofloxacina, Gentamicina, Penicilina y Trimetropim-Sulfametoxasol. Se determina-ron los péptidos deL. plantarummediante HPLC y la cinética de crecimiento en dossustratos (MRS y Pro, midiéndose: biomasa, pH, consumo de azúcar total y ácidoláctico. Se observó un mejor crecimiento bajo pH 3.25, sales biliares 5%, bilis bovina2% y temperatura de 45°C con valores de 3.0·1012, 2.3·1012, 8.6·1011y 3.0·1012UFC/ml, respectivamente.L. plantarumy el sobrenadante inhibieron aY. pseudotuberculosis,con halos de 3 y 5 mm. Se observó resistencia deL. plantarumyY. pseudotuberculosisaPenicilina y Dicloxacilina, respectivamente, con sensibilidad de ambas cepas a los demásantibióticos. Se evidenciaron los péptidos VAL-TIR-VAL y TIR-GLI-GLI-FA-METen el sobrenadante deL. plantarum. Durante la fase logarítmica para los medios MRSy Pro se alcanzaron valores de 6.75·1012y 1.20·1012UFC/ml (biomasa, 6.96 y 5.49(pH, y 0.65 y 0.76%, (ácido láctico, respectivamente. La comparación de los mediosmediante un diseño de bloques al azar (P> 0.05, mostró similar comportamiento.L.plantarumdemostró su potencial probiótico en condicionesin vitro.

  5. Prevalence of fur mites (Chirodiscoides caviae) in pet guinea pigs (Cavia porcellus) in southern Italy.

    Science.gov (United States)

    d'Ovidio, Dario; Santoro, Domenico

    2014-04-01

    Chirodiscoides caviae is the most common fur mite affecting guinea pigs; infestation is generally asymptomatic. No studies have been published on the prevalence of such mites in guinea pigs in southern Italy. We sought to evaluate the prevalence and the clinical signs of C. caviae infestation in guinea pigs in southern Italy. Clinical records of guinea pigs evaluated from August 2012 to July 2013 were retrospectively searched. In this retrospective matched case-control study, records of guinea pigs with evidence of C. caviae infestation were selected. The prevalence of C. caviae infestation was evaluated and exposure variables were assessed among guinea pigs with and without infestation using stepwise conditional logistic regression. Guinea pigs seen during the same time period, but without a diagnosis of C. caviae, were included as control animals. The prevalence of C. caviae was 32% (42 of 131); 66.6% of affected guinea pigs (28 of 42) originated from pet shops, whereas 28% (14 of 42) were privately owned. Thirty-one guinea pigs (73.8%) were asymptomatic, whereas 11 (26.1%) showed clinical signs (pruritus, alopecia, erythema and scaling). The most frequently affected area was the lumbosacral region (38 of 42). Guinea pigs in pet shops were more likely to be affected by C. caviae than owned guinea pigs (odds ratio, 5.12; 95% confidence interval, 2.32-11.29; P guinea pigs in southern Italy. Chirodiscoides mites should be sought in guinea pigs, particularly in animals coming from pet shops. © 2014 ESVD and ACVD.

  6. Genética poblacional de cobayas de Colombia, Cavia spp. (Rodentia: Caviidae con marcadores moleculares RAPD

    Directory of Open Access Journals (Sweden)

    Héctor Aníbal Campos

    2008-09-01

    Full Text Available En el presente estudio, mostramos los primeros resultados moleculares de formas colombianas de Cavia. Claramente, la población silvestre de C. anolaimae fue genéticamente diferenciada de la forma doméstica, C. porcellus, tal como ha sido demostrado por otros autores utilizando resultados morfométricos, osteológicos y cariotípicos. Ambas especies mostraron un considerable nivel de diversidad genética, aunque el segundo taxon mostró niveles mayores de esta diversidad. Los niveles de heterogeneidad genética también fueron mayores entre las poblaciones de C. porcellus (F ST = 0.254 que entre las poblaciones de C. anolaimae (F ST = 0.118. Esos niveles significativos de heterogeneidad genética, y los consiguientes bajos niveles de flujo génico, fueron discutidos comparativamente con los resultados por otros autores analizando otros marcadores moleculares (citocromo-b mitocondrial. Los resultados aquí mostrados son coherentes con un complejo proceso de domesticación en Cavia porcellus.Population genetics of Colombian Guinea Pigs, Cavia spp. (Rodentia: Caviidae with RAPD molecular markers. The genus Cavia occurs in South America, mainly in grasslands.. We collected blood samples from 97 individuals in six field populations and analyzed them with RAPD molecular markers. One wild type (C. anolaimae was differentiated from the domestic form (C. porcellus, in agreement with other authors who used morphological, osteological and karyotipic results. Genetic diversity was considerable in both species, but higher in C. porcellus. The levels of genetic heterogeneity were also higher among the populations of C. porcellus (F ST = 0.254 than among the populations of C. anolaimae (F ST = 0.118. These significant levels of genetic heterogeneity, and the low levels of gene flow, were consistent with a complex domestication process for Cavia porcellus. Rev. Biol. Trop. 56 (3: 1481-1501. Epub 2008 September 30.

  7. Aeromonas caviae septicemia in immunocompetent gastrointestinal carriers

    Directory of Open Access Journals (Sweden)

    M. Dwivedi

    Full Text Available Aeromonas caviae strains have been isolated from blood and stool cultures of three immunocompetent patients, residents of Northern India, who presented with community acquired septicemia without any recent history of diarrhea. Cell culture infectivity test performed on Hep-2 cells have shown substantial degree of invasiveness in the isolated strains. This case unleashes a possibility of asymptomatic gastrointestinal carriage of such strains of A. caviae in a very large population of India, as several areas of India have very high rates of Aeromonas induced acute diarrhea/gastroenteritis (up to 13%. It needs to be appraised further in India as well as other countries having high rates of Aeromonas induced acute diarrhea/gastroenteritis.

  8. Pyruvate kinase blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003357.htm Pyruvate kinase blood test To use the sharing features on this page, ... energy when oxygen levels are low. How the Test is Performed A blood sample is needed. In the laboratory, white blood ...

  9. PYRUVATE FERMENTATION BY STREPTOCOCCUS FAECALIS.

    Science.gov (United States)

    DEIBEL, R H; NIVEN, C F

    1964-07-01

    Deibel, R. H. (American Meat Institute Foundation, Chicago, Ill.), and C. F. Niven, Jr. Pyruvate fermentation by Streptococcus faecalis. J. Bacteriol. 88:4-10. 1964.-Streptococcus faecalis, as opposed to S. faecium, utilizes pyruvate as an energy source for growth. The fermentation is adaptive, as demonstrated by growth experiments in a casein-hydrolysate medium and the fermentation of pyruvate by cell suspensions. The principal products of pyruvate catabolism were acetoin, CO(2), and lactic, acetic, and formic acids, although carbon recoveries were low due to the formation of slime. End-product analyses suggested that both the phosphoroclastic and dismutation systems were active in pyruvate breakdown. Studies with cell-free extracts indicated a thiamine diphosphate requirement for active pyruvate catabolism. The involvement of lipoic acid in the phosphoroclastic system was investigated, and, although inconclusive results were obtained, no association of this cofactor with phosphoroclastic activity could be made.

  10. Performances de production des cobayes (Cavia porcellus L.) en ...

    African Journals Online (AJOL)

    Production performance of guinea pigs (Cavia porcellus L.) in function of dietary protein level. ABSTRACT. In Cameroon, guinea pigs raising is still practiced in kitchens and on the ground and their food is ... females were previously crossed with 12 males for a period of 31 days according to a factorial design of three.

  11. Leishmaniose cutânea em cobaias (Cavia porcellus Cutaneous leishmaniasis in guinea pigs (Cavia porcellus

    Directory of Open Access Journals (Sweden)

    Roselene Ecco

    2000-06-01

    Full Text Available São descritos três casos de leishmaniose cutânea em cobaias (Cavia porcellus machos de dois anos de idade que eram criadas como animais de estimação. As lesões macroscópicas eram semelhantes em duas cobaias e consistiam de nódulos cutâneos ulcerados no aspecto dorsal do pavilhão auricular de ambas as orelhas. Na outra cobaia, a lesão consistia de engrossamentos irregulares na pele do escroto que apareceram após uma orquiectomia realizada dois meses antes. A histopatologia era semelhante nos três casos e consistia de acentuada dermatite granulomatosa, com ulceração e numerosas formas protozoárias amastigotas no citoplasma de macrófagos, sugestivas de Leishmania sp. A microscopia eletrônica confirmou o diagnóstico de leishmaniose.Three cases of cutaneous leishmaniasis in three two-year-old male guinea pigs (Cavia porcellus raised as pets are described. Gross lesions were similar in two of the guinea pigs and consisted of raised and ulcerated cutaneous nodules in the dorsal aspect of the pinna of both ears. In another guinea pig the lesion consisted of irregular thickenning in the skin of the scrotum which followed an orchiectomy performed two months before. Histopathology was similar in the three cases and consisted of severe diffuse granulomatous dermatitis with ulceration and numerous intrahistiocytic protozoal amastigotes resembling Leishmania sp. Electron microscopy confirmed the diagnosis of leishmaniasis.

  12. CAViaR-based forecast for oil price risk

    International Nuclear Information System (INIS)

    Huang, Dashan; Yu, Baimin; Fabozzi, Frank J.; Fukushima, Masao

    2009-01-01

    As a benchmark for measuring market risk, value-at-risk (VaR) reduces the risk associated with any kind of asset to just a number (amount in terms of a currency), which can be well understood by regulators, board members, and other interested parties. This paper employs a new VaR approach due to Engle and Manganelli [Engle, R.F., Manganelli, S., 2004. CAViaR: Conditional Autoregressive Value at Risk by Regression Quantiles. Journal of Business and Economic Statistics 22, 367-381] to forecasting oil price risk. In doing so, we provide two original contributions by introducing a new exponentially weighted moving average CAViaR model and developing a mixed data regression model for multi-period VaR prediction. (author)

  13. Aeromonas caviae strain induces Th1 cytokine response in mouse intestinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, S L; Lye, D J; McKinstry, Craig A.; Vesper, Sephen J.

    2010-01-01

    Aeromonas caviae has been associated with human gastrointestinal disease. Strains of this species typically lack virulence factors (VFs) such as enterotoxins and hemolysins that are produced by other human pathogens of the Aeromonas genus. Microarray profiling of murine small intestinal extracts, 24 hours after oral infection with an A. caviae strain, provides evidence of a Th1 type immune response. A large number of gamma-interferon (γ-IFN) induced genes are up-regulated as well as several tumor necrosis factor-alpha (TNF-α) transcripts. A. caviae has always been considered as opportunistic pathogen because it lacks obvious virulence factors. This current effort suggests that an A. caviae strain can colonize the murine intestinal tract and cause what has been described by others as a dysregulatory cytokine response. This response could explain why a number of diarrheal waterborne disease cases have been attributed to A. caviae even though it lacks obvious enteropathogenic properties.

  14. Genetics Home Reference: pyruvate carboxylase deficiency

    Science.gov (United States)

    ... condition has been reported mostly in Europe, particularly France. Affected infants have severe lactic acidosis, a buildup ... Pyruvate carboxylase deficiency MalaCards: pyruvate carboxylase deficiency Merck Manual Consumer Version: Overview of Hereditary Metabolic Disorders Orphanet: ...

  15. Isolated tumoral pyruvate dehydrogenase can synthesize acetoin which inhibits pyruvate oxidation as well as other aldehydes.

    Science.gov (United States)

    Baggetto, L G; Lehninger, A L

    1987-05-29

    Oxidation of 1 mM pyruvate by Ehrlich and AS30-D tumor mitochondria is inhibited by acetoin, an unusual and important metabolite of pyruvate utilization by cancer cells, by acetaldehyde, methylglyoxal and excess pyruvate. The respiratory inhibition is reversed by other substrates added to pyruvate and also by 0.5 mM ATP. Kinetic properties of pyruvate dehydrogenase complex isolated from these tumor mitochondria have been studied. This complex appears to be able to synthesize acetoin from acetaldehyde plus pyruvate and is competitively inhibited by acetoin. The role of a new regulatory pattern for tumoral pyruvate dehydrogenase is presented.

  16. Spinach Pyruvate Kinase Isoforms 1

    Science.gov (United States)

    Baysdorfer, Chris; Bassham, James A.

    1984-01-01

    Pyruvate kinase from spinach (Spinacea oleracea L.) leaves consists of two isoforms, separable by blue agarose chromatography. Both isoforms share similar pH profiles and substrate and alternate nucleotide Km values. In addition, both isoforms are inhibited by oxalate and ATP and activated by AMP. The isoforms differ in their response to three key metabolites; citrate, aspartate, and glutamate. The first isoform is similar to previously reported plant pyruvate kinases in its sensitivity to citrate inhibition. The Ki for this inhibition is 1.2 millimolar citrate. The second isoform is not affected by citrate but is regulated by aspartate and glutamate. Aspartate is an activator with a Ka of 0.05 millimolar, and glutamate is an inhibitor with a Ki of 0.68 millimolar. A pyruvate kinase with these properties has not been previously reported. Based on these considerations, we suggest that the activity of the first isoform is regulated by respiratory metabolism. The second isoform, in contrast, may be regulated by the demand for carbon skeletons for use in ammonia assimilation. PMID:16663425

  17. Aeromonas caviae strain induces Th1 cytokine response in mouse intestinal tract

    Science.gov (United States)

    Aeromonas caviae has been associated with human gastrointestinal disease. Strains of this species typically lack virulence factors (VFs) such as enterotoxins and hemolysins that are produced by other human pathogens of the Aeromonas genus,. Microarray profiling of...

  18. Le cobaye Cavia porcellus L., comme animal de boucherie au Cameroun

    OpenAIRE

    Ngou Ngoupayou, JD.; Fotso, JM.; Kouonmenioc, J.

    1994-01-01

    Guinea Pig Cavia porcellus L. As A Meat Producing Animal In Cameroon. Guinea pig Cavia porcellus farming for meat production remains a marginalised activity in Cameroon in spite of the advantages this specie offers. With the view to promote its production, a national countrywide survey was carried out in order to evaluate the production systems and constraints. Traditional guinea pig farming appears to be a secondary household activity undertaken by small farmers basically women. The extensiv...

  19. Dynamics of pyruvate metabolism in Lactococcus lactis

    DEFF Research Database (Denmark)

    Melchiorsen, Claus Rix; Jensen, Niels B.S.; Christensen, Bjarke

    2001-01-01

    The pyruvate metabolism in the lactic acid bacterium Lactococcus lactis was studied in anaerobic cultures under transient conditions. During growth of L. lactis in continuous culture at high dilution rate, homolactic product formation was observed, i.e., lactate was produced as the major end...... product. At a lower dilution rate, the pyruvate metabolism shifted towards mixed acid-product formation where formate, acetate, and ethanol were produced in addition to lactate. The regulation of the shift in pyruvate metabolism was investigated by monitoring the dynamic behavior of L. lactis...

  20. Photochemistry of aqueous pyruvic acid.

    Science.gov (United States)

    Griffith, Elizabeth C; Carpenter, Barry K; Shoemaker, Richard K; Vaida, Veronica

    2013-07-16

    The study of organic chemistry in atmospheric aerosols and cloud formation is of interest in predictions of air quality and climate change. It is now known that aqueous phase chemistry is important in the formation of secondary organic aerosols. Here, the photoreactivity of pyruvic acid (PA; CH3COCOOH) is investigated in aqueous environments characteristic of atmospheric aerosols. PA is currently used as a proxy for α-dicarbonyls in atmospheric models and is abundant in both the gas phase and the aqueous phase (atmospheric aerosols, fog, and clouds) in the atmosphere. The photoreactivity of PA in these phases, however, is very different, thus prompting the need for a mechanistic understanding of its reactivity in different environments. Although the decarboxylation of aqueous phase PA through UV excitation has been studied for many years, its mechanism and products remain controversial. In this work, photolysis of aqueous PA is shown to produce acetoin (CH3CHOHCOCH3), lactic acid (CH3CHOHCOOH), acetic acid (CH3COOH), and oligomers, illustrating the progression from a three-carbon molecule to four-carbon and even six-carbon molecules through direct photolysis. These products are detected using vibrational and electronic spectroscopy, NMR, and MS, and a reaction mechanism is presented accounting for all products detected. The relevance of sunlight-initiated PA chemistry in aqueous environments is then discussed in the context of processes occurring on atmospheric aerosols.

  1. Paraspidodera uncinata (Nematoda, Lauroiinae as parasite of Cavia magna and Cavia aperea (Rodentia, Caviidae in southern Brazil

    Directory of Open Access Journals (Sweden)

    Ana Gabriela da Silva Rocha

    2015-05-01

    Full Text Available Out of the 5 species of Guinea pig registered for Brazil, 4 (Cavia fulgida, C. porcellus, C. aperea, and C. magna have already been reported as hosts of Paraspidodera uncinata. The rodent species C. magna and C. aperea are small-sized mammals, with terrestrial habits, which occur from southern Brazil to eastern Uruguay. Guinea pig specimens donated for research were necropsied for the analysis of endoparasites, and the nematodes found were identified as P. uncinata. The microhabitats of this species were the small and large intestines in C. magna and the large intestine in C. aperea. The prevalence of P. uncinata in the hosts was 60% in C. magna (n = 5 and 14% in C. aperea (n = 7. The record of P. uncinata in different Guinea pig species allows inferring that the foraging mode is similar in the different locations where they occur in southern Brazil, because, perhaps, the infection of hosts has occurred through the ingestion of vegetables contaminated with P. uncinata eggs. This study contributes to knowledge on the helminth fauna of C. magna and C. aperea in southern Brazil.

  2. Crystal structure of Cryptosporidium parvum pyruvate kinase.

    Directory of Open Access Journals (Sweden)

    William J Cook

    Full Text Available Pyruvate kinase plays a critical role in cellular metabolism of glucose by serving as a major regulator of glycolysis. This tetrameric enzyme is allosterically regulated by different effector molecules, mainly phosphosugars. In response to binding of effector molecules and substrates, significant structural changes have been identified in various pyruvate kinase structures. Pyruvate kinase of Cryptosporidium parvum is exceptional among known enzymes of protozoan origin in that it exhibits no allosteric property in the presence of commonly known effector molecules. The crystal structure of pyruvate kinase from C. parvum has been solved by molecular replacement techniques and refined to 2.5 Å resolution. In the active site a glycerol molecule is located near the γ-phosphate site of ATP, and the protein structure displays a partially closed active site. However, unlike other structures where the active site is closed, the α6' helix in C. parvum pyruvate kinase unwinds and assumes an extended conformation. In the crystal structure a sulfate ion is found at a site that is occupied by a phosphate of the effector molecule in many pyruvate kinase structures. A new feature of the C. parvum pyruvate kinase structure is the presence of a disulfide bond cross-linking the two monomers in the asymmetric unit. The disulfide bond is formed between cysteine residue 26 in the short N-helix of one monomer with cysteine residue 312 in a long helix (residues 303-320 of the second monomer at the interface of these monomers. Both cysteine residues are unique to C. parvum, and the disulfide bond remained intact in a reduced environment. However, the significance of this bond, if any, remains unknown at this time.

  3. Learning and personality types are related in cavies (Cavia aperea).

    Science.gov (United States)

    Guenther, Anja; Brust, Vera; Dersen, Mona; Trillmich, Fritz

    2014-02-01

    The evolution and maintenance of consistent individual differences, so called animal personalities, have attracted much research interest over the past decades. Variation along common personality traits, such as boldness or exploration, is often associated with risk-reward trade-offs. Individuals that are bolder and hence take more risks may be more successful in acquiring resources over the short term. Cautious individuals taking fewer risks may, on the other hand, live longer, but may also gather fewer resources over the short term. According to recent theory, individual differences in personality may be functionally related to individual differences in cognitive performance (i.e., the way in which individuals acquire or use information). Individual differences in the acquisition speed of cognitively challenging tasks are often associated with a speed-accuracy trade-off. Accuracy can be improved by investing more time in the decision-making process or, conversely, decisions can be made more quickly at the cost of making more mistakes. Hence, the speed-accuracy trade-off often involves a risk-reward trade-off. We tested whether 3 personality traits, boldness, activity, and aggressiveness, are correlated with individual learning, associative learning speed, and behavioral flexibility as assessed by reversal learning in wild cavies (Cavia aperea). We found strong positive relationships between all personality traits and learning speed, whereas flexibility was negatively associated with aggressiveness. Our results support the hypothesis that performance reflects individual differences in personality in a predictable way. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  4. Isolation of Aeromonas caviae from yoghurt (“nono”) sold in Jos ...

    African Journals Online (AJOL)

    A total of 30 nono samples were collected from Farin Gada, Bauchi Road and Gangare markets in Jos and analysed for the presence of Aeromonas species. 3 (10%) of the 30 nono samples were positive for Aeromonas species; which was found to be Aeromonas caviae. All the isolates were obtained from non-heat treated ...

  5. Chlamydia caviae infection alters abundance but not composition of the guinea pig vaginal microbiota.

    Science.gov (United States)

    Neuendorf, Elizabeth; Gajer, Pawel; Bowlin, Anne K; Marques, Patricia X; Ma, Bing; Yang, Hongqiu; Fu, Li; Humphrys, Michael S; Forney, Larry J; Myers, Garry S A; Bavoil, Patrik M; Rank, Roger G; Ravel, Jacques

    2015-06-01

    In humans, the vaginal microbiota is thought to be the first line of defense again pathogens including Chlamydia trachomatis. The guinea pig has been extensively used as a model to study chlamydial infection because it shares anatomical and physiological similarities with humans, such as a squamous vaginal epithelium as well as some of the long-term outcomes caused by chlamydial infection. In this study, we aimed to evaluate the guinea pig-C. caviae model of genital infection as a surrogate for studying the role of the vaginal microbiota in the early steps of C. trachomatis infection in humans. We used culture-independent molecular methods to characterize the relative and absolute abundance of bacterial phylotypes in the guinea pig vaginal microbiota in animals non-infected, mock-infected or infected by C. caviae. We showed that the guinea pig and human vaginal microbiotas are of different bacterial composition and abundance. Chlamydia caviae infection had a profound effect on the absolute abundance of bacterial phylotypes but not on the composition of the guinea pig vaginal microbiota. Our findings compromise the validity of the guinea pig-C. caviae model to study the role of the vaginal microbiota during the early steps of sexually transmitted infection. © FEMS 2015.

  6. Een bijdrage tot de kennis van de experimentele tuberculeuze super-infectie bij de cavia

    NARCIS (Netherlands)

    Goslinga, Jan

    1960-01-01

    Er werd een beschrijving gegeven van een in 1954 in het sanatorium "de KLOKKENBERG" te Breda verricht onderzoek, waarbij 37 caviae achtereenvolgens enkele malen met virulente, tegen bepaalde stoffen selectief resistent gekweekte tuberkelbacteriën, afgeleid van &n bepaalde, bij een van de patienten

  7. Do young guinea pigs (Cavia porcellus) develop an attachment to inanimate objects?

    NARCIS (Netherlands)

    Janzen, MID; Timmermans, PJA; Kruijt, JP; Vossen, JMH

    1999-01-01

    Filial imprinting has been studied extensively in precocial birds. In these studies, inanimate objects were used as imprinting objects. Although attachment to the parents is common in mammals, experiments with inanimate objects are rare and mostly restricted to guinea pigs (Cavia porcellus). The

  8. Moderate excess of pyruvate augments osteoclastogenesis

    Directory of Open Access Journals (Sweden)

    Jenna E. Fong

    2013-03-01

    Cell differentiation leads to adaptive changes in energy metabolism. Conversely, hyperglycemia induces malfunction of many body systems, including bone, suggesting that energy metabolism reciprocally affects cell differentiation. We investigated how the differentiation of bone-resorbing osteoclasts, large polykaryons formed through fusion and growth of cells of monocytic origin, is affected by excess of energy substrate pyruvate and how energy metabolism changes during osteoclast differentiation. Surprisingly, small increases in pyruvate (1–2 mM above basal levels augmented osteoclastogenesis in vitro and in vivo, while larger increases were not effective in vitro. Osteoclast differentiation increased cell mitochondrial activity and ATP levels, which were further augmented in energy-rich conditions. Conversely, the inhibition of respiration significantly reduced osteoclast number and size. AMP-activated protein kinase (AMPK acts as a metabolic sensor, which is inhibited in energy-rich conditions. We found that osteoclast differentiation was associated with an increase in AMPK levels and a change in AMPK isoform composition. Increased osteoclast size induced by pyruvate (1 mM above basal levels was prevented in the presence of AMPK activator 5-amino-4-imidazole carboxamide ribonucleotide (AICAR. In keeping, inhibition of AMPK using dorsomorphin or siRNA to AMPKγ increased osteoclast size in control cultures to the level observed in the presence of pyruvate. Thus, we have found that a moderate excess of pyruvate enhances osteoclastogenesis, and that AMPK acts to tailor osteoclastogenesis to a cell's bioenergetics capacity.

  9. IDENTIFIKASI NEMATODA PARASIT PADA SALURAN PENCERNAAN MARMUT (Cavia cobaya SEBAGAI SUMBER BELAJAR BIOLOGI PADA MATERI INVERTEBRATA

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    Septia Nurhasanah

    2014-05-01

    Full Text Available The research was conducted in the Laboratory of Science Education, University of Muhammadiyah Metro. The research is a descriptive analysis, morphological observations were made by identifying the nematode parasite found that Trichostrongylus sp, Strongyloides sp, Trichuris sp, Trichuris sp. The results showed the prevalence and intensity values is the large number of guinea pigs to parasites divided by the number of guinea pigs that are 100% inspected. While the intensity is seen from the total number of nematode parasites that infect in the number of guinea pigs infected with a parasite that is 2,3. The population in this study was 10 cows pigs (Cavia cobaya . This study took a part in the digestion of marmots (Cavia cobaya the intestines and stomach , then cut and taken part in the large intestine and be Indian ink or coloring 2-3 drops to be easily identified microscopically . Put the preparations into a petri dish , and given alcohol as much as 96 % with 2-3 drops . Taking part in the examination of the large intestine to taste then used the nematode worm structure with Indian ink dye to be observed , and placed in the glass object . Observed with a microscope. Document if the parasites are found by using the camera Erlina 2008. Identification of the observations made have found 3 types of parasites that attack the guinea pig (Cavia cobaya is Strongyloides sp on samples 1,2,3,4,5,6 , dan10 . Then parasite Trichuris sp species found in samples 8 and 9. Trichostrongylus sp parasite species found in sample 7 . Parasitic nematodes found were 3 types of Trichostrongylus sp, Strongyloides sp, Trichuris sp. Number of samples that have been observed as many as 10 cows pigs (Cavia cobaya , with the overall result is as much as 23 tails parasites.               Kata kunci: nematode parasit, marmut (Cavia cobaya, sumber belajar biologi.

  10. Microorganisms and methods for producing pyruvate, ethanol, and other compounds

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Jennifer L.; Zhang, Xiaolin

    2017-12-26

    Microorganisms comprising modifications for producing pyruvate, ethanol, and other compounds. The microorganisms comprise modifications that reduce or ablate activity of one or more of pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase, phosphate acetyltransferase, acetate kinase, pyruvate oxidase, lactate dehydrogenase, cytochrome terminal oxidase, succinate dehydrogenase, 6-phosphogluconate dehydrogenase, glutamate dehydrogenase, pyruvate formate lyase, pyruvate formate lyase activating enzyme, and isocitrate lyase. The microorganisms optionally comprise modifications that enhance expression or activity of pyruvate decarboxylase and alcohol dehydrogenase. The microorganisms are optionally evolved in defined media to enhance specific production of one or more compounds. Methods of producing compounds with the microorganisms are provided.

  11. Injury Thresholds for Topical Cream-Coated Skin of Hairless Guinea Pigs (Cavia Procellus) in Near Infrared Region

    National Research Council Canada - National Science Library

    Stolarski, David J; Zohner, Justin J; Imholte, Michelle L; Chavey, Lucas J; Pocock, Ginger M; Buchanan, Kelvin C; Jindra, Nichole M; Figueroa, Manuel A; Thomas, Robert J; Rockwell, Benjamin A

    2006-01-01

    .... Hairless guinea pigs (cavia porcellus) in vivo were used to evaluate how the minimum visible lesion threshold for single-pulse laser exposure is changed with a topical agent applied to the skin...

  12. Production of pyruvate from mannitol by mannitol-assimilating pyruvate decarboxylase-negative Saccharomyces cerevisiae.

    Science.gov (United States)

    Yoshida, Shiori; Tanaka, Hideki; Hirayama, Makoto; Murata, Kousaku; Kawai, Shigeyuki

    2015-01-01

    Mannitol is contained in brown macroalgae up to 33% (w/w, dry weight), and thus is a promising carbon source for white biotechnology. However, Saccharomyces cerevisiae, a key cell factory, is generally regarded to be unable to assimilate mannitol for growth. We have recently succeeded in producing S. cerevisiae that can assimilate mannitol through spontaneous mutations of Tup1-Cyc8, each of which constitutes a general corepressor complex. In this study, we demonstrate production of pyruvate from mannitol using this mannitol-assimilating S. cerevisiae through deletions of all 3 pyruvate decarboxylase genes. The resultant mannitol-assimilating pyruvate decarboxylase-negative strain produced 0.86 g/L pyruvate without use of acetate after cultivation for 4 days, with an overall yield of 0.77 g of pyruvate per g of mannitol (the theoretical yield was 79%). Although acetate was not needed for growth of this strain in mannitol-containing medium, addition of acetate had a significant beneficial effect on production of pyruvate. This is the first report of production of a valuable compound (other than ethanol) from mannitol using S. cerevisiae, and is an initial platform from which the productivity of pyruvate from mannitol can be improved.

  13. Streptococcus caviae sp. nov., isolated from guinea pig faecal samples.

    Science.gov (United States)

    Palakawong Na Ayudthaya, Susakul; Hilderink, Loes J; Oost, John van der; Vos, Willem M de; Plugge, Caroline M

    2017-05-01

    A novel cellobiose-degrading and lactate-producing bacterium, strain Cavy grass 6T, was isolated from faecal samples of guinea pigs (Cavia porcellus). Cells of the strain were ovalshaped, non-motile, non-spore-forming, Gram-stain-positive and facultatively anaerobic. The strain gr at 25-40 °C (optimum 37 °C) and pH 4.5-9.5 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cavy grass 6T belongs to the genus Streptococcus with its closest relative being Streptococcus devriesei CCUG 47155T with only 96.5 % similarity. Comparing strain Cavy grass 6T and Streptococcus devriesei CCUG 47155T, average nucleotide identity and level of digital DNA-DNA hybridization dDDH were only 86.9 and 33.3 %, respectively. Housekeeping genes groEL and gyrA were different between strain Cavy grass 6T and other streptococci. The G+C content of strain Cavy grass 6T was 42.6±0.3 mol%. The major (>10 %) cellular fatty acids of strain Cavy grass 6T were C16:0, C20 : 1ω9c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). Strain Cavy grass 6T ferment a range of plant mono- and disaccharides as well as polymeric carbohydrates, including cellobiose, dulcitol, d-glucose, maltose, raffinose, sucrose, l-sorbose, trehalose, inulin and dried grass extract, to lactate, formate, acetate and ethanol. Based on phylogenetic and physiological characteristics, Cavy grass 6T can be distinguished from other members of the genus Streptococcus. Therefore, a novel species of the genus Streptococcus, family Streptococcaceae, order Lactobacillales is proposed, Streptococcuscaviae sp. nov. (type strain Cavy grass 6T=TISTR 2371T=DSM 102819T).

  14. Étude expérimentale sur la reproduction chez le cobaye ( Cavia ...

    African Journals Online (AJOL)

    Objectif : Une étude expérimentale sur les paramètres de la reproduction chez le cobaye (Cavia porcellus) élevé en zone périphérique de Kinshasa a été réalisée. Son objectif est d'apprendre aux éleveurs des cobayes une gestion rationnelle de la reproduction par un choix judicieux des femelles actives à la saillie, ...

  15. Anatomy of the heart of Guinea pig fetuses in late gestation (Cavia porcellus [Linnaeus, 1758])

    OpenAIRE

    Mariangela de Toledo Barbino; Claudia Marinovic Oliveira; Erika Toledo Fonseca; Phelipe de Oliveira Favaron; Márcio Nogueira Rodrigues; Maria Angélica Miglino

    2011-01-01

    This study has been developed in order to describe the anatomy of the heart of Guinea pig (Cavia porcellus [Linnaeu,1758]) fetuses in late gestation and to obtain anatomical characteristics that can support and help the understanding of the physiology of fetal circulation. Fetuses have been collected from three female in late gestation, which were described and photographed macroscopically, trhough light microscopy in HE and scanning electronic microscopy. The fetal heart is divided into four...

  16. Loss of Mitochondrial Pyruvate Carrier 2 in Liver Leads to Defects in Gluconeogenesis and Compensation via Pyruvate-Alanine Cycling

    Science.gov (United States)

    McCommis, Kyle S.; Chen, Zhouji; Fu, Xiaorong; McDonald, William G.; Colca, Jerry R.; Kletzien, Rolf F.; Burgess, Shawn C.; Finck, Brian N.

    2015-01-01

    SUMMARY Pyruvate transport across the inner mitochondrial membrane is believed to be a prerequisite step for gluconeogenesis in hepatocytes, which is important for maintenance of normoglycemia during prolonged food deprivation, but also contributes to hyperglycemia in diabetes. To determine the requirement for mitochondrial pyruvate import in gluconeogenesis, mice with liver-specific deletion of mitochondrial pyruvate carrier 2 (LS-Mpc2−/−) were generated. Loss of MPC2 impaired, but did not completely abolish, hepatocyte pyruvate metabolism, labelled pyruvate conversion to TCA cycle intermediates and glucose, and glucose production from pyruvate. Unbiased metabolomic analyses of livers from fasted LS-Mpc2−/− mice suggested that alterations in amino acid metabolism, including pyruvate-alanine cycling, might compensate for loss of MPC2. Indeed, inhibition of pyruvate-alanine transamination further reduced mitochondrial pyruvate metabolism and glucose production by LS-Mpc2−/− hepatocytes. These data demonstrate an important role for MPC2 in controlling hepatic gluconeogenesis and illuminate a compensatory mechanism for circumventing a block in mitochondrial pyruvate import. PMID:26344101

  17. The effect of infectious dose on humoral and cellular immune responses in Chlamydophila caviae primary ocular infection.

    Directory of Open Access Journals (Sweden)

    Ana Filipovic

    Full Text Available Following infection, the balance between protective immunity and immunopathology often depends on the initial infectious load. Several studies have investigated the effect of infectious dose; however, the mechanism by which infectious dose affects disease outcomes and the development of a protective immune response is not known. The aim of this study was to investigate how the infectious dose modulates the local and systemic humoral and the cellular immune responses during primary ocular chlamydial infection in the guinea pig animal model. Guinea pigs were infected by ocular instillation of a Chlamydophila caviae-containing eye solution in the conjunctival sac in three different doses: 1×102, 1×104, and 1×106 inclusion forming units (IFUs. Ocular pathology, chlamydial clearance, local and systemic C. caviae-specific humoral and cellular immune responses were assessed. All inocula of C. caviae significantly enhanced the local production of C. caviae-specific IgA in tears, but only guinea pigs infected with the higher doses showed significant changes in C. caviae-specific IgA levels in vaginal washes and serum. On complete resolution of infection, the low dose of C. caviae did not alter the ratio of CD4+ and CD8+ cells within guinea pigs' submandibular lymph node (SMLN lymphocytes while the higher doses increased the percentages of CD4+ and CD8+ cells within the SMLN lymphocytes. A significant negative correlation between pathology intensity and the percentage of CD4+ and CD8+ cells within SMLN lymphocyte pool at selected time points post-infection was recorded for both 1×104, and 1×106 IFU infected guinea pigs. The relevance of the observed dose-dependent differences on the immune response should be further investigated in repeated ocular chlamydial infections.

  18. Efecto modulador del sulfuro de hidrógeno en el metabolismo basal en Cavia porcellus (cuy) normales

    OpenAIRE

    Gómez Herreros, César Gonzalo

    2016-01-01

    Evalúa el efecto modulador del H2S a 80 ppm sobre el metabolismo basal en Cavia porcellus (cuy) normales. Para ello mide el consumo de oxígeno y producción de dióxido de carbono del Cavia porcellus (cuy) normales inmediatamente antes y después de la exposición al sulfuro de hidrógeno. Para luego determinar los cambios histológicos a nivel de tejido pulmonar, cardiaco y renal, y los niveles de hemoglobina entre los grupos experimentales (control, experimental y gold estándar). Tesis

  19. Characterisation of potential virulence markers in Aeromonas caviae isolated from polluted and unpolluted aquatic environments in Morocco

    DEFF Research Database (Denmark)

    Imziln, Boujama; Krovacek, Karel; Baloda, Suraj B.

    1998-01-01

    .406) than those isolated from raw sewage (PVI = 0.175) or those from river waters (PVI = 0.09). These results suggest that stabilisation pond systems used for sewage purification under arid climate conditions in Marrakech, may have selected potentially enteropathogenic A. caviae strains.......A total of 100 Aeromonas caviae strains isolated from river waters (38 isolates), raw sewage (30 isolates) and effluents of stabilisation ponds (i.e. treated sewage; 32 isolates) in Marrakech, Morocco, were tested for the presence of putative virulence factors to delineate differences, if any...

  20. Ethyl pyruvate protects colonic anastomosis from ischemia-reperfusion injury.

    Science.gov (United States)

    Unal, B; Karabeyoglu, M; Huner, T; Canbay, E; Eroglu, A; Yildirim, O; Dolapci, M; Bilgihan, A; Cengiz, O

    2009-03-01

    Ethyl pyruvate is a simple derivative in Ca(+2)- and K(+)-containing balanced salt solution of pyruvate to avoid the problems associated with the instability of pyruvate in solution. It has been shown to ameliorate the effects of ischemia-reperfusion (I/R) injury in many organs. It has also been shown that I/R injury delays the healing of colonic anastomosis. In this study, the effect of ethyl pyruvate on the healing of colon anastomosis and anastomotic strength after I/R injury was investigated. Anastomosis of the colon was performed in 32 adult male Wistar albino rats divided into 4 groups of 8 individuals: (1) sham-operated control group (group 1); (2) 30 minutes of intestinal I/R by superior mesenteric artery occlusion (group 2); (3) I/R+ ethyl pyruvate (group 3), ethyl pyruvate was administered as a 50-mg/kg/d single dose; and (4) I/R+ ethyl pyruvate (group 4), ethyl pyruvate administration was repeatedly (every 6 hours) at the same dose (50 mg/kg). On the fifth postoperative day, animals were killed. Perianastomotic tissue hydroxyproline contents and anastomotic bursting pressures were measured in all groups. When the anastomotic bursting pressures and tissue hydroxyproline contents were compared, it was found that they were decreased in group 2 when compared with groups 1, 3, and 4 (P .05). Ethyl pyruvate significantly prevents the delaying effect of I/R injury on anastomotic strength and healing independent from doses of administration.

  1. Molecular diversity among domestic guinea-pigs (Cavia porcellus and their close phylogenetic relationship with the Andean wild species Cavia tschudii Diversidad molecular entre cuyes domésticos (Cavia porcellus y su relación filogenética cercana con la especie silvestre andina Cavia tschudii

    Directory of Open Access Journals (Sweden)

    ÁNGEL E SPOTORNO

    2004-06-01

    Full Text Available To investigate the origin and diversity of domestic guinea-pigs Cavia porcellus (Linnaeus, 1758; Rodentia, Caviidae, we sequenced the mitochondrial cytochrome b gene of 12 domestic and 10 wild specimens from six species, including the two presumed as ancestral to the domestic one: Cavia tschudii and Cavia aperea. All maximum parsimony and maximum likelihood analyses grouped C. porcellus with C. tschudii (mean K2P distance = 3.2 %; best trees had 609 steps (CI = 0.796; Bremer support Index (SI = 28, and a _Ln = 4419.52, with 100 % and 97 % bootstrap support respectively. This clade, supported by three substitutions and 96 % bootstrap, is also obtained in the cladistic analysis of corresponding amino acids. When the C. aperea node was forced to join C. porcellus, these trees were consistently longer, less likely and robust, and with less defining characters than the optimal one. All C. porcellus sequences also clustered in a node defined by 15 substitutions. The sub-node containing animals from city markets, pet shops and laboratories was characterized by four substitutions (one non-silent, SI = 7, and 91 % bootstrap. Some South American C. porcellus, called "criollos" (creoles by local breeders, were more diverse. Probably, a particular clade from southern Peru and Chile may represent a pre-Columbian lineage. Mean K2P distance between C. tschudii and C. aperea was rather large, 7.7 %. Cavia appeared as a robust node (100 % bootstrap. These results indicate that C. tschudii is the species most closely related to C. porcellusPara investigar el origen y la divergencia de los cuyes domésticos Cavia porcellus (Linnaeus, 1758; Rodentia, Caviidae, secuenciamos el gen mitocondrial para citocromo b de 12 especímenes domésticos y 10 silvestres de seis especies, incluyendo las dos que se presumen como ancestro de la doméstica: C. tschudii y C. aperea. Todos los análisis de máxima parsimonia y máxima verosimilitud agruparon a C. porcellus con C

  2. Pyruvate carboxylase is expressed in human skeletal muscle

    DEFF Research Database (Denmark)

    Minet, Ariane D; Gaster, Michael

    2010-01-01

    Pyruvate carboxylase (PC) is a mitochondrial enzyme that catalyses the carboxylation of pyruvate to oxaloacetate thereby allowing supplementation of citric acid cycle intermediates. The presence of PC in skeletal muscle is controversial. We report here, that PC protein is easily detectable...

  3. Production and Recovery of Pyruvic Acid: Recent Advances

    Science.gov (United States)

    Pal, Dharm; Keshav, Amit; Mazumdar, Bidyut; Kumar, Awanish; Uslu, Hasan

    2017-12-01

    Pyruvic acid is an important keto-carboxylic acid and can be manufactured by both chemical synthesis and biotechnological routes. In the present paper an overview of recent developments and challenges in various existing technique for the production and recovery of pyruvic acid from fermentation broth or from waste streams has been presented. The main obstacle in biotechnological production of pyruvic acid is development of suitable microorganism which can provide high yield and selectivity. On the other hand, technical limitation in recovery of pyruvic acid from fermentation broth is that, it could not be separated as other carboxylic acid in the form of salts by addition of alkali. Besides, pyruvic acid cannot be crystallized. Commercial separation by distillation is very expensive because pyruvic acid decomposes at higher temperature. It is also chemically reactive due to its peculiar molecular structure and has tendency to polymerize. Thus, at high concentration the various type of reaction leads to lower yield of the product, and hence, conventional methods are not favorable. Alternate separation technologies viable to both synthetic and biological routes are the current research areas. Latest techniques such as reactive extraction is new to the field of recovery of pyruvic acid. Recent development and future prospects in downstream processing of biochemically produced pyruvic acids has been discussed in this review article.

  4. Characterization of a C4 maize pyruvate orthophosphate dikinase ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... concert with cytosolic NADP-malic enzymes (NADP-ME) could play a role in gluconeogenetic phosphoenol- pyruvate (PEP) generation from pyruvate during stomatal closure. The recent application of recombinant DNA tech- nology to plant metabolism has considerably advanced our understanding of the ...

  5. Characterisation of potential virulence markers in Aeromonas caviae isolated from polluted and unpolluted aquatic environments in Morocco

    DEFF Research Database (Denmark)

    Imziln, Boujama; Krovacek, Karel; Baloda, Suraj B.

    1998-01-01

    A total of 100 Aeromonas caviae strains isolated from river waters (38 isolates), raw sewage (30 isolates) and effluents of stabilisation ponds (i.e. treated sewage; 32 isolates) in Marrakech, Morocco, were tested for the presence of putative virulence factors to delineate differences, if any...

  6. Cloning, DNA sequence, and expression of Aeromonas caviae WS7b chitinase gene.

    Science.gov (United States)

    Malik, Amarila; Wenuganen, S; Suwanto, Antonius; Tjahjono, Budi

    2003-01-01

    A chitinase-producing bacterium, designated WS7b, was isolated from a soil sample obtained from a black-pepper plantation on Bangka Island, Indonesia. Fatty-acid methyl-ester analysis indicated that the isolate was Aeromonas caviae. A chitinase gene from WS7b was cloned in a pUC19-based plasmid vector, but without its natural promoter. The complete nucleotide sequence of the gene was determined, and the structural gene consisted of a 2748-bp region encoding 864 amino acids. DNA sequence analysis indicated that the gene had been cloned without its promoter, and this was confirmed by chitinase-plate assay of the truncated version of the gene in Escherichia coli. The chitinase gene product showed amino-acid sequence similarity to chiA from A. caviae. Chitinase enzyme activity was determined spectrophotometrically, using colloidal chitin azure as substrate for extracellular and intracellular fractions. The ability of the chitinase cloned in E. coli to hydrolyze chitin was less than that of the enzyme in its indigenous host.

  7. Le cobaye Cavia porcellus L., comme animal de boucherie au Cameroun

    Directory of Open Access Journals (Sweden)

    Ngou Ngoupayou, JD.

    1994-01-01

    Full Text Available Guinea Pig Cavia porcellus L. As A Meat Producing Animal In Cameroon. Guinea pig Cavia porcellus farming for meat production remains a marginalised activity in Cameroon in spite of the advantages this specie offers. With the view to promote its production, a national countrywide survey was carried out in order to evaluate the production systems and constraints. Traditional guinea pig farming appears to be a secondary household activity undertaken by small farmers basically women. The extensive production system which reveals no management practices, integrates very well in the agricultural systems (small livestock, food crops and natural forages production of the western highlands and southern forest zones of Cameroon. Guinea pig productivity remains low due to many constraints such as predation, uncontrolled breeding, inbreeding, poor feeding, negative selection and lack of veterinary care. Nevertheless, guinea pig farming plays an important role in the well being of low income village dwellers as food security, cash savings and socio-cultural values within the populations of South Cameroon. The promotion of its production requires an awareness of animal scientists, development authorities, as well as on station research if improved raising conditions.

  8. Effet de Panicum maximum sur la productivité des femelles primipares durant le cycle de reproduction chez le cobaye (Cavia porcellus L.)

    OpenAIRE

    Danho, M.; Thys, E.; N'Goran D.V. Kouakou; Nogbou Assidjo, E.; Grongnet, JF.

    2012-01-01

    Effect of Panicum maximum on Productivity of Primiparous Females during Reproduction Cycle in Guinea Pigs (Cavia porcellus L.). In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L.) are mainly fed with Panicum maximum. To assess the effect of the latter during pregnancy and lactation (RC) of these animals, primiparous dams were fed ad libitum, Panicum maximum alone during the RC (MOD1) or associated with pellets for rabbits during lactation (MOD2), or associated with pellets for ra...

  9. Pyruvate decarboxylases from the petite-negative yeast Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Møller, Kasper; Langkjær, Rikke Breinhold; Nielsen, Jens

    2004-01-01

    Saccharomyces kluyveri is a petite-negative yeast, which is less prone to form ethanol under aerobic conditions than is S. cerevisiae. The first reaction on the route from pyruvate to ethanol is catalysed by pyruvate decarboxylase, and the differences observed between S. kluyveri and S. cerevisiae...... is not due to differences in the regulation of pyruvate decarboxylase(s), but rather to differences in the regulation of the TCA cycle and the respiratory machinery. However, the PDC genes of Saccharomyces/Kluyveromyces yeasts differ in their genetic organization and phylogenetic origin. While S. cerevisiae...

  10. Induction of Rhizopus oryzae pyruvate decarboxylase genes.

    Science.gov (United States)

    Skory, Christopher D

    2003-07-01

    Two pyruvate decarboxylase genes, pdcA, and pdcB, were cloned from Rhizopus oryzae. These genes are similar to each other with approximately 85% nucleotide sequence identity within the coding region. Multiple transcriptional start sites and polyadenylation sites were found for both genes. The deduced translation product of each gene results in a 561 amino acid protein with approximate molecular weight of 61 kDa each. The amino acid identity between the two proteins was 91% as calculated by Lipmann-Pearson comparisons. Transcriptional control appears to be important in regulation of the PDC, since much of the transcript accumulation parallels enzymatic activity. There was no detectable pdc transcript from cultures grown in glycerol-containing medium. Induction of transcription for pdcA and pdcB was initiated within 1.5 h of adding glucose to the culture. Shifting the aerobically grown cultures to anoxic conditions at this time resulted in enhanced pdc transcription, PDC enzymatic activity, and ethanol production, compared to cultures with continued aerobic growth.

  11. Phenotypic and molecular genetic analysis of Pyruvate Kinase ...

    African Journals Online (AJOL)

    Phenotypic and molecular genetic analysis of Pyruvate Kinase deficiency in a Tunisian family. Jaouani Mouna, Hamdi Nadia, Chaouch Leila, Kalai Miniar, Mellouli Fethi, Darragi Imen, Boudriga Imen, Chaouachi Dorra, Bejaoui Mohamed, Abbes Salem ...

  12. 21 CFR 862.1650 - Pyruvate kinase test system.

    Science.gov (United States)

    2010-04-01

    ...). Measurements obtained by this device are used in the diagnosis and treatment of various inherited anemias due to pyruvate kinase deficiency or of acute leukemias. (b) Classification. Class I (general controls...

  13. Blastocyst recovery and multifactorial gene expression analysis in the wild guinea pig (Cavia aperea).

    Science.gov (United States)

    Hribal, Romy; Guenther, Anja; Rübensam, Kathrin; Jewgenow, Katarina

    2016-09-15

    The expression of specific developmentally important genes in preimplantation embryos is an accepted marker for unraveling the influence of single factors in studies that are mostly related to artificial reproduction techniques. Such studies, however, often reveal high levels of heterogeneity between single embryos, independently of the influence of factors of interest. A possible explanation for this variation could be the large variety of physiological and environmental factors to which early embryos are exposed and their ability to react to them. Here, we investigated several potentially important parameters of development at the same time, in blastocysts of the wild guinea pig (Cavia aperea) generated in vivo after natural mating. The optimal time for flushing fully developed blastocysts was between 123 and 126 hours after mating. The abundance of POU5F1 (P = 0.042), BAX (P multifactorial environment. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. A new karyotype for the genus Cavia from a southern island of Brazil (Rodentia - Caviidae

    Directory of Open Access Journals (Sweden)

    A. Gava

    1998-03-01

    Full Text Available Intraspecific karyotype variation in mammal species is very common and often caused by centromeric fusion of acrocentric chromosomes. We describe here a new karyotype 2n = 62 (FN = 112 for the genus Cavia from the Moleques do Sul Islands, of the southern coast of Brazil. We analyzed two male and four female karyotypes that had twenty-four biarmed pairs and six pairs of acrocentric chromosomes. The sexual pair consisted of a metacentric X-chromosome and a large acrocentric Y. C-bands were found in the centromeric and pericentromeric regions of almost all chromosomes, except for some small biarmed and acrocentric ones. Nucleolus organizer regions appeared in two biarmed chromosomes, and G-banding patterns were also seen.RESUMO A variação cariotípica nas espécies de mamíferos é bastante comum e geralmente causada pela fusão de cromossomos acrocêntricos. Foi descrito neste trabalho um novo cariótipo, com 2n = 62 e FN = 112, para o gênero Cavia proveniente das ilhas Moleques do Sul, da costa sul do Brasil. Foram analisados os cariótipos de dois machos e quatro fêmeas que possuiam 24 pares de cromossomos com dois braços e seis pares de acrocêntricos. O par sexual era constituído por um cromossomo X metacêntrico grande e um Y acrocêntrico. As bandas C estavam localizadas nas regiões centroméricas e pericentroméricas da maioria dos cromossomos, com exceção de alguns acrocêntricos e os cromossomos de dois braços menores. As regiões organizadoras de nucléolo ocorreram em dois cromossomos com dois braços e o padrão de bandamento G foi também apresentado.

  15. Exogenous pyruvate accelerates glycolysis and promotes capacitation in human spermatozoa

    Science.gov (United States)

    Hereng, T.H.; Elgstøen, K.B.P.; Cederkvist, F.H.; Eide, L.; Jahnsen, T.; Skålhegg, B.S.; Rosendal, K.R.

    2011-01-01

    BACKGROUND There has been an ongoing debate in the reproductive field about whether mammalian spermatozoa rely on glycolysis, oxidative phosphorylation or both for their energy production. Recent studies have proposed that human spermatozoa depend mainly on glucose for motility and fertilization but the mechanism behind an efficient glycolysis in human spermatozoa is not well understood. Here, we demonstrate how human spermatozoa utilize exogenous pyruvate to enhance glycolytic ATP production, motility, hyperactivation and capacitation, events that are crucial for male fertility. METHODS Purified human spermatozoa from healthy donors were incubated under capacitating conditions (including albumin, bicarbonate and glucose) and tested for changes in ATP levels, motility, hyperactivation and tyrosine phosphorylation after treatment with pyruvate. The experiments were repeated in the presence of sodium cyanide in order to assess the contribution from mitochondrial respiration. The metabolism of 13C labeled glucose and pyruvate was traced by a combination of liquid chromatography and mass spectrometry. RESULTS The treatment of human spermatozoa with exogenous pyruvate increased intracellular ATP levels, progressive motility and hyperactivation by 56, 21 and 130%, respectively. In addition, added pyruvate induced a significant increase in tyrosine phosphorylation levels. Blocking of the electron transport chain did not markedly affect the results, indicating that the mechanism is independent of oxidative phosphorylation. However, the observed effects could be counteracted by oxamate, an inhibitor of lactate dehydrogenase (LDH). Metabolic tracing experiments revealed that the observed rise in ATP concentration resulted from an enhanced glycolytic flux, which was increased by more than 50% in the presence of exogenous pyruvate. Moreover, all consumed 13C labeled pyruvate added was converted to lactate rather than oxidized in the tricarboxylic acid cycle. CONCLUSIONS Human

  16. CLORURO DE BENZALCONIO EN EL TRATAMIENTO DE LA DERMATOMICOSIS CAUSADA POR Trichophyton sp. EN EL CUY (Cavia cobayo)

    OpenAIRE

    Bezada Q., Sandra; Práctica privada.; Noé M., Norma; Laboratorio de Medicina Veterinaria Preventiva, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima Perú.; Béjar C., Vilma; Instituto de Medicina Tropical “DAC”, Universidad Nacional Mayor de San Marcos, Lima Perú.; Mascari G., Juan; Instituto Nacional de Investigación Agraria (INIA)

    2013-01-01

    The efficacy of benzalkonium chloride for the treatment of dermatomicosis caused by Trichophyton sp. in guinea pig (Cavia cobayo) was evaluated in 200 guinea pigs of two months old, that showed typical clinical signs of dermatomicosis. Hair samples and skin grudges were taken for direct exam and for in vitro culture in Dermatophytes Test Medium and Mycobiotic. Skin biopsies for pathobiology were prepared. The guinea pig were divided in groups A and B of 100 animals each. Group A was treated w...

  17. Bioconversion of α-chitin into N-acetyl-glucosamine using chitinases produced by marine-derived Aeromonas caviae isolates.

    Science.gov (United States)

    Cardozo, Flávio Augusto; Gonzalez, Juan Miguel; Feitosa, Valker Araujo; Pessoa, Adalberto; Rivera, Irma Nelly Gutierrez

    2017-10-27

    N-Acetyl-D-glucosamine (GlcNAc) is a monosaccharide with great application potential in the food, cosmetic, pharmaceutical, and biomaterial areas. GlcNAc is currently produced by chemical hydrolysis of chitin, but the current processes are environmentally unfriendly, have low yield and high cost. This study demonstrates the potential to produce GlcNAc from α-chitin using chitinases of ten marine-derived Aeromonas isolates as a sustainable alternative to the current chemical process. The isolates were characterized as Aeromonas caviae by multilocus sequence analysis (MLSA) using six housekeeping genes (gltA, groL, gyrB, metG, ppsA, and recA), not presented the virulence genes verified (alt, act, ast, ahh1, aer, aerA, hlyA, ascV and ascFG), but showed hemolytic activity on blood agar. GlcNAc was produced at 37 °C, pH 5.0, 2% (w/v) colloidal chitin and crude chitinase extracts (0.5 U mL -1 ) by all the isolates with yields from 14 to 85% at 6 h, 17-89% at 12 h and 19-93% after 24 h. The highest yield of GlcNAc was observed by A. caviae CH129 (93%). This study demonstrates one of the most efficient chitin enzymatic hydrolysis procedures and A. caviae isolates with great potential for chitinases expression and GlcNAc production.

  18. Ethyl Pyruvate Emerges as a Safe and Fast Acting Agent against Trypanosoma brucei by Targeting Pyruvate Kinase Activity.

    Directory of Open Access Journals (Sweden)

    Netsanet Worku

    Full Text Available Human African Trypanosomiasis (HAT also called sleeping sickness is an infectious disease in humans caused by an extracellular protozoan parasite. The disease, if left untreated, results in 100% mortality. Currently available drugs are full of severe drawbacks and fail to escape the fast development of trypanosoma resistance. Due to similarities in cell metabolism between cancerous tumors and trypanosoma cells, some of the current registered drugs against HAT have also been tested in cancer chemotherapy. Here we demonstrate for the first time that the simple ester, ethyl pyruvate, comprises such properties.The current study covers the efficacy and corresponding target evaluation of ethyl pyruvate on T. brucei cell lines using a combination of biochemical techniques including cell proliferation assays, enzyme kinetics, phasecontrast microscopic video imaging and ex vivo toxicity tests. We have shown that ethyl pyruvate effectively kills trypanosomes most probably by net ATP depletion through inhibition of pyruvate kinase (Ki = 3.0±0.29 mM. The potential of ethyl pyruvate as a trypanocidal compound is also strengthened by its fast acting property, killing cells within three hours post exposure. This has been demonstrated using video imaging of live cells as well as concentration and time dependency experiments. Most importantly, ethyl pyruvate produces minimal side effects in human red cells and is known to easily cross the blood-brain-barrier. This makes it a promising candidate for effective treatment of the two clinical stages of sleeping sickness. Trypanosome drug-resistance tests indicate irreversible cell death and a low incidence of resistance development under experimental conditions.Our results present ethyl pyruvate as a safe and fast acting trypanocidal compound and show that it inhibits the enzyme pyruvate kinase. Competitive inhibition of this enzyme was found to cause ATP depletion and cell death. Due to its ability to easily cross

  19. Carbohydrate metabolism during prolonged exercise and recovery: interactions between pyruvate dehydrogenase, fatty acids, and amino acids

    DEFF Research Database (Denmark)

    Mourtzakis, Marina; Saltin, B.; Graham, T.

    2006-01-01

    During prolonged exercise, carbohydrate oxidation may result from decreased pyruvate production and increased fatty acid supply and ultimately lead to reduced pyruvate dehydrogenase (PDH) activity. Pyruvate also interacts with the amino acids alanine, glutamine, and glutamate, whereby the decline...... amino acid taken up during exercise and recovery. Alanine and glutamine were also associated...... with pyruvate metabolism, and they comprised 68% of total amino-acid release during exercise and recovery. Thus reduced pyruvate production was primarily associated with reduced carbohydrate oxidation, whereas the greatest production of pyruvate was related to glutamate, glutamine, and alanine metabolism...

  20. Advantages of pyruvate over lactate in peritoneal dialysis solutions.

    Science.gov (United States)

    Zhou, F Q

    2001-05-01

    This review discusses effects of both lactate and pyruvate, and high glucose in peritoneal dialysis solutions (PDS) on leukocytes, mainly on intracellular pH ([pH](i)), glucose metabolic pathways, and apoptosis. Lactate-based PDS (L-PDS) are bioincompatible primarily due to the low pH, high lactate, and glucose excess in both individual and combination. High lactate in an acidi milieu would induce severe intracellular acidosis of leukocytes, and high glucose may disturb glucose metabolic pathways and activate protein kinase C (PKC) and nuclear factor-kappa B (NF-kappaB) of the cells, leading to apoptosis. Pyruvate-based PDS (P-PDS) are novel experimental PDS. Evidence shows that P-PDS are superior in biocompatibility. Pyruvate protection of cells has been confirmed in many fields besides the PDS area. Although the underlying mechanism whereby P-PDS preserve cell function is not fully understood, it may be associated with the maintenance of [pH](i) close to physiological, due to its low buffering capacity, improvement of cellular glucose metabolic pathways and redox state, and sustainment of intracellular calcium ([Ca2+]i) homeostasis in high glucose concentrations. It may also inhibit PKC and NF-kappaB activation in high glucose. In addition, pyruvate is a strong antioxidant, a scavenger of hydrogen peroxide (H2O2). However, exogenous pyruvate in PDS could not be an energy source for cells and also the Crabtree effect might not occur in neutrophils. Pyruvate is a hopeful candidate of buffers in PDS in the near future. Further observation of P-PDS is strongly needed with peritoneal cells to verify the cell protection both in vitro and in vivo before clinic trials.

  1. Exogenous pyruvate facilitates cancer cell adaptation to hypoxia by serving as an oxygen surrogate.

    Science.gov (United States)

    Yin, Chengqian; He, Dan; Chen, Shuyang; Tan, Xiaoling; Sang, Nianli

    2016-07-26

    Molecular oxygen is the final electron acceptor in cellular metabolism but cancer cells often become adaptive to hypoxia, which promotes resistance to chemotherapy and radiation. The reduction of endogenous glycolytic pyruvate to lactate is known as an adaptive strategy for hypoxic cells. Whether exogenous pyruvate is required for hypoxic cell proliferation by either serving as an electron acceptor or a biosynthetic substrate remains unclear. By using both hypoxic and ρ0 cells defective in electron transfer chain, we show that exogenous pyruvate is required to sustain proliferation of both cancer and non-cancer cells that cannot utilize oxygen. Particularly, we show that absence of pyruvate led to glycolysis inhibition and AMPK activation along with decreased NAD+ levels in ρ0 cells; and exogenous pyruvate increases lactate yield, elevates NAD+/NADH ratio and suppresses AMPK activation. Knockdown of lactate dehydrogenase significantly inhibits the rescuing effects of exogenous pyruvate. In contrast, none of pyruvate-derived metabolites tested (including acetyl-CoA, α-ketoglutarate, succinate and alanine) can replace pyruvate in supporting ρ0 cell proliferation. Knockdown of pyruvate carboxylase, pyruvate dehydrogenase and citrate synthase do not impair exogenous pyruvate to rescue ρ0 cells. Importantly, we show that exogenous pyruvate relieves ATP insufficiency and mTOR inhibition and promotes proliferation of hypoxic cells, and that well-oxygenated cells release pyruvate, providing a potential in vivo source of pyruvate. Taken together, our data support a novel pyruvate cycle model in which oxygenated cells release pyruvate for hypoxic cells as an oxygen surrogate. The pyruvate cycle may be targeted as a new therapy of hypoxic cancers.

  2. Histopathological analysis of UV-B irradiated retina by Cavia Coba'ya and with protection of transmission light lambda 550-600 nm.

    Science.gov (United States)

    Vojniković, Bozidar; Vojniković, Davor; Brcić, Luka

    2007-01-01

    In 14 experimental Cavia Coba'ya eyes were irradiated with UV-B light, lambda 312 nm, 25 J/cm2 in 15 minute exposure. Including the transmission of light through optical media: cornea, lens, humor aqueous and vitreous body, and pupil surface of 7 mm2, we can calculate that in these conditions retina can be really irradiated with 10 J/cm2. The half number of Cavia Coba'ya was simultaneously irradiated with visible light, lambda of 550-600 nm (1000 Lx). Control group was 5 Cavia Coba'ya. Two months after irradiation, eyes were enucleated and fixed in 4% formaldehyde. Histopathological findings showed alterations of all retinal layers: loss of ganglion cells, axons, reduction of photoreceptors, vacuolar degeneration and hyperplasia of retinal pigment epithelium. In the second group of irradiance, the eyes with visible light lambda 550-600 nm, all retinal alterations were in 50% decreased.

  3. Cloning, sequencing and expression of the gene encoding the extracellular metalloprotease of Aeromonas caviae.

    Science.gov (United States)

    Kawakami, K; Toma, C; Honma, Y

    2000-01-01

    A gene (apk) encoding the extracellular protease of Aeromonas caviae Ae6 has been cloned and sequenced. For cloning the gene, the DNA genomic library was screened using skim milk LB agar. One clone harboring plasmid pKK3 was selected for sequencing. Nucleotide sequencing of the 3.5 kb region of pKK3 revealed a single open reading frame (ORF) of 1,785 bp encoding 595 amino acids. The deduced polypeptide contained a putative 16-amino acid signal peptide followed by a large propeptide. The N-terminal amino acid sequence of purified recombinant protein (APK) was consistent with the DNA sequence. This result suggested a mature protein of 412 amino acids with a molecular mass of 44 kDa. However, the molecular mass of purified recombinant APK revealed 34 kDa by SDS-PAGE, suggesting that further processing at the C-terminal region took place. The 2 motifs of zinc binding sites deduced are highly conserved in the APK as well as in other zinc metalloproteases including Vibrio proteolyticus neutral protease, Emp V from Vibrio vulnificus, HA/P from Vibrio cholerae, and Pseudomonas aeruginosa elastase. Proteolytic activity was inhibited by EDTA, Zincov, 1,10-phenanthroline and tetraethylenepentamine while unaffected by the other inhibitors tested. The protease showed maximum activity at pH 7.0 and was inactivated by heating at 80 C for 15 min. These results together suggest that APK belongs to the thermolysin family of metalloendopeptidases.

  4. [Dermatophyte colonization on guinea pigs (Cavia porcellus) kept in pet stores. First report from Santiago, Chile].

    Science.gov (United States)

    Thomson, Pamela; Monsalves, Pamela; Maier, Liliana; Silva, Víctor

    2015-01-01

    Dermatophytes are pathogenic fungi that can be present in the flora of mammals, such as dogs, cats and rodents, which can be a source and transmission vehicle to other hosts, including humans. In Chile, there is a steady increase of acquiring guinea pigs (Cavia porcellus) as pets, with no local studies on their colonization by dermatophytes. To determine the presence of dermatophytes on clinically healthy guinea pigs, kept in pet stores in Santiago, Chile. A total of 52 clinically healthy animals were studied using the method by Mariat and Tapia (1966). The specimen culture and identification of the dermatophytes were performed using classical mycological procedures. Four guinea pigs (7.7%) out of 52 were colonized by dermatophytes, and were identified as Trichophyton mentagrophytes (3 cases) and Trichophyton verrucosum (one case). This study shows, for the first time in Chile, that guinea pigs can be colonized by dermatophytes, which should alert administrators of pet stores, veterinarians and physicians, to keep this in mind when purchasing or looking after this type of pet in a veterinary office. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  5. Congenital malformations caused by Stryphnodendron fissuratum (Leg. Mimosoideae) in guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Macedo, Josenaldo S; Rocha, Brena P; Colodel, Edson M; Freitas, Sílvio H; Dória, Renata G S; Riet-Correa, Franklin; Evêncio-Neto, Joaquim; Mendonça, Fábio S

    2015-11-01

    The aim of this study was to evaluate the toxicity of Stryphnodendron fissuratum pods in guinea pigs (Cavia porcellus) and test the hypothesis that this plant has teratogenic effects. Thus, sixteen guinea pigs were randomly divided into four groups of four animals each. Groups 10, 20 and 40 consisted of guinea pigs that received commercial food that contained crushed pods of S. fissuratum at concentrations of 10, 20 and 40 g/kg, respectively, during the period of organogenesis. Control group consisted of guinea pigs under the same management conditions that did not receive crushed pods of S. fissuratum in their food. In all experimental groups, the main clinical signs of poisoning consisted of anorexia, prostration, absence of vocalizations, alopecia, diarrhea, and abortions within the adult guinea pigs. Those that did not abort gave birth to weak, malnourished pups, some of which had fetal malformations. The main teratogenic changes consisted of eventration, arthrogryposis, amelia of the forelimbs, anophthalmia, microphthalmia, anotia and agnathia. The reductions in the number of offspring and the malformations observed in the experimental groups suggest that S. fissuratum affects fetal development and is teratogenic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Temperature Preference in IAF Hairless and Hartley Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Kleven, Gale A; Joshi, Prianca

    2016-03-01

    The Hairless strain of guinea pigs (Cavia porcellus) is the result of a spontaneous recessive mutation first identified at the Institute Armand Frappier (IAF) in 1978. Despite the longstanding availability of this strain, little is known about its thermoregulatory behavior. The aim of this study was to determine temperature preference in Hartley and Hairless guinea pigs by observing each strain in a ring-shaped apparatus containing a nonlinear temperature gradient. Temperatures were maintained by separately controlled heating mats lining the apparatus. Set point temperatures ranged from 24 to 38 °C. Guinea pigs (Hartley female, Hairless female, and Hairless male guinea pigs; n = 8 each group) were placed either singly or in pairs at 1 of the 8 randomized starting points within the apparatus. Subjects were observed for 30 min and coded for location within the temperature gradient by both frequency and duration. When placed singly in the apparatus, all 3 groups spent more time in the 30 °C zones. However, when placed as pairs with a cagemate, Hartley female guinea pigs spent more time in the cooler range of temperatures from 24 to 30 °C, whereas Hairless guinea pigs preferred a range of 30 to 38 °C. These results confirm a temperature preference of 30 ± 2 °C for both Hartley and Hairless guinea pigs when singly housed. However, data from the paired housing condition suggest that context plays an important role in thermoregulatory behavior.

  7. Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region.

    Science.gov (United States)

    Limon, Georgina; Gonzales-Gustavson, Eloy A; Gibson, Troy J

    2016-01-01

    Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO2) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO2 stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs.

  8. Seasonally different reproductive investment in a medium-sized rodent (Cavia aperea).

    Science.gov (United States)

    Rübensam, K; Hribal, R; Jewgenow, K; Guenther, A

    2015-09-01

    Pronounced seasonal variations in day length, temperature, and resource availability characterize the temperate regions and strongly influence the animals living in these environments. To survive and reproduce successfully, animals must allocate resources among competing physiological systems, and they usually adjust their time of breeding to the most adequate season. Here, we examined whether reproductive investment in the wild guinea pig (Cavia aperea) differs across seasons. We kept animals in combined indoor-outdoor enclosures under natural light and temperature year-round. We measured littering probability, litter size, and birth weight, as well as maternal weight loss during lactation. In addition, we measured ovulation rate as a parameter to adjust reproductive investment prenatally. Our data reveal strong seasonal variations in reproductive traits despite the fact that the animals reproduced year-round. The results show a reduced reproductive investment in winter, indicated by a lower litter size and birth weight of pups, whereas investment was highest in warm seasons (summer and autumn) with higher litter size and birth weight. Maternal weight loss in lactation was highest in cold seasons even if the litter size was lower. Furthermore, we found the regulation on the proximate level of the reproductive investment, the ovulation rate, to differ significantly between the seasons. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Anatomy of the heart of Guinea pig fetuses in late gestation (Cavia porcellus [Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Mariangela de Toledo Barbino

    2011-09-01

    Full Text Available This study has been developed in order to describe the anatomy of the heart of Guinea pig (Cavia porcellus [Linnaeu,1758] fetuses in late gestation and to obtain anatomical characteristics that can support and help the understanding of the physiology of fetal circulation. Fetuses have been collected from three female in late gestation, which were described and photographed macroscopically, trhough light microscopy in HE and scanning electronic microscopy. The fetal heart is divided into four cavities, it is surrounded by the pericardium, and it has three layers: epicardium, myocardium, and endocardium. Foramen ovale has a great importance in the fetal circulation, but it could not be visualized in sections carried out in this study. Through these results we conclude that the hearts of Guinea pig fetuses differ from those of other species in structures such as the cranial vena cava, which is not divided into left and right, and that the walls thickness of left and right ventricles does not differ significantly.

  10. Measuring Contagion of Subprime Crisis Based on MVMQ-CAViaR Method

    Directory of Open Access Journals (Sweden)

    Wuyi Ye

    2014-01-01

    Full Text Available The analysis of financial contagion is a topical issue in international finance and portfolio management. In this paper, we investigate whether the global financial crisis originating from American subprime crisis spreads to China, Japan, UK, France, and Germany. Firstly, multivariate conditional autoregressive value at risk (MV-CAViaR models are applied to the whole sample to analyze the variation of market risk among these countries. By dividing the sampling period into three important subperiods (precrisis period, crisis period, and recovery period, we examine the changes of the dependence structure of risk during each period. Comparing with the situations in precrisis period, if the estimated coefficients become significant or market risk increases during the crisis, it implies the existence of contagion from the angle of coefficient significance or risk. The findings show that the concerned coefficients are significant or the market risks of the tested countries increase during the crisis except for China. The results imply that there is contagion from the US to all other countries, except for China. Furthermore, the changes of the market risk are found to be consistent with market events and media reports during that period.

  11. ATOMIC-STRUCTURE OF THE CUBIC CORE OF THE PYRUVATE-DEHYDROGENASE MULTIENZYME COMPLEX

    NARCIS (Netherlands)

    MATTEVI, A; OBMOLOVA, G; SCHULZE, E; KALK, KH; WESTPHAL, AH; DEKOK, A; HOL, WGJ

    1992-01-01

    The highly symmetric pyruvate dehydrogenase multienzyme complexes have molecular masses ranging from 5 to 10 million daltons. They consist of numerous copies of three different enzymes: pyruvate dehydrogenase, dihydrolipoyl transacetylase, and lipoamide dehydrogenase. The three-dimensional crystal

  12. Ethyl Pyruvate Provides Therapeutic Benefits to Resuscitation Fluids

    Science.gov (United States)

    2009-02-01

    worsen survival in endotoxemia [33] depending on the dose and time of administration [34]. These results reveal the need to study the factors...described in previous studies [40]. Animals without resuscitation were characterized by uremia, metabolic acidosis and hyperglycemia. Both resuscitation...AnGap) and negative base excess of extracellular fluid (BEecf). Resuscitation with Hextend alone or with ethyl pyruvate improved metabolic acidosis

  13. Pyruvate decarboxylases from the petite-negative yeast Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Møller, Kasper; Langkjær, Rikke Breinhold; Nielsen, Jens

    2004-01-01

    is not due to differences in the regulation of pyruvate decarboxylase(s), but rather to differences in the regulation of the TCA cycle and the respiratory machinery. However, the PDC genes of Saccharomyces/Kluyveromyces yeasts differ in their genetic organization and phylogenetic origin. While S. cerevisiae...

  14. Studies on the structure and function of pyruvate dehydrogenase complexes

    NARCIS (Netherlands)

    Abreu, de R.

    1978-01-01

    The aim of the present investigation was to obtain more information of the structure and function of the pyruvate dehydrogenase complexes from Azotobacter vinelandii and Escherichia coli.

    In chapter 2 a survey is given of the recent literature on

  15. Effect of glucose, lactate and pyruvate concentrations on in vitro ...

    African Journals Online (AJOL)

    Jane

    2011-08-01

    Aug 1, 2011 ... lactate and pyruvate), hormones, cytokines and vitamins on oocyte maturation and the development of pre- implantation embryos, because it eliminates undefined factors present in serum or serum albumin (Bavister,. 1995; Herrick et al., 2006). Although a role for energy substrates has been stated for ...

  16. Perioperative care of an infant with pyruvate dehydrogenase ...

    African Journals Online (AJOL)

    The authors present the anaesthetic management of two infants with pyruvate dehydrogenase complex deficiency (PDCD), a rare genetic disorder of carbohydrate metabolism leading to lactic acidosis and neurological impairment. In the first case, a seven-month-old infant, undergoing closed reduction of a dislocated hip, ...

  17. Characterization of a C 4 maize pyruvate orthophosphate dikinase ...

    African Journals Online (AJOL)

    Pyruvate orthophosphate dikinase (PPDK) is a key enzyme in plants that utilize the C4 photosynthetic pathway to fix CO2. The enzymatic reaction catalyzed by PPDK is critically controlled by light and is one of the rate-limiting steps of the C4 pathway. The intact maize (Zea mays) C4-PPDK gene, containing its own promoter, ...

  18. Effect of glucose, lactate and pyruvate concentrations on in vitro ...

    African Journals Online (AJOL)

    Carbohydrates are among the most influential of the numerous components of culture medium that affect metabolism and developmental potential. Glucose, lactate and pyruvate are required for the growth of oocytes and other follicular cells in vitro. The aim of this study was to determine the effects of different concentrations ...

  19. Lactate-pyruvate interconversion in blood: implications for in vivo tracer studies

    NARCIS (Netherlands)

    Romijn, J. A.; Chinkes, D. L.; Schwarz, J. M.; Wolfe, R. R.

    1994-01-01

    We have evaluated lactate and pyruvate kinetics in whole blood or plasma by the addition of [1-13C]lactate (n = 5) or [1-13C]pyruvate (n = 5) and application of compartmental modeling to the resulting data. Pyruvate and lactate concentrations and tracer-to-tracee ratios were measured at frequent

  20. Enzymatic synthesis of 11C-pyruvic acid and 11C-L-lactic acid

    International Nuclear Information System (INIS)

    Cohen, M.B.; Spolter, L.; Chang, C.C.; Cook, J.S.; Macdonald, N.S.

    1980-01-01

    L-Lactic acid is formed as the end product of glycolysis under anaerobic conditions in all cells, but this reaction is of special significance in the myocardium. L-Lactic acid is reversibly formed from and is in equilibrium with myocardial pyruvic acid, which is its sole metabolic pathway. 11 C-Pyruvic acid is synthesized from 11 C carbon dioxide using pyruvate-ferredoxin oxidoreductase and coenzymes. The 11 C-pyruvic acid is then converted to 11 -L-lactic acid by lactic acid dehydrogenase. The availability of 11 C-pyruvic acid and 11 C-L-lactic acid will permit the in vivo investigation of lactate metabolism. (author)

  1. Leucocyte profile and offspring production of guinea pig (Cavia cobaya given Anredera cordifolia leaf extract

    Directory of Open Access Journals (Sweden)

    D. Wijayanti

    2018-03-01

    Full Text Available The objective of this study was to determine leucocyte and offspring production of guinea pig (Cavia cobaya giving Anredera cordifolia leaf extract. Materials used were female 16 heads of guinea pig with body weight of 425g. The treatments were an extract of A. cordifolia leaf at doses of 0, 10, 50 and 90 mg/head, designated as T0, T1, T2 and T3, respectively. A. cordifolia leaf extract was administered orally from 10 days prepartum to 10 days postpartum. Blood was taken at 10 days prepartum and 10 days postpartum. Total birth of the offspring was observed. Data were analyzed by analysis of variance and if there was effect of treatment, then continued with Duncan multiple range test and Chi-Square test for fetal production between the given A. cordifolia leaf extract and control. The result showed that there was no significant difference for 10 days prepartum after addition of A cordifolia leaf extract treatment. The postpartum treated showed a total 50 mg/head level increaed for monocytes than that of level 0, 10 and 90 mg/head. Ten days postpartum treatment showed the total increase for leucocyte and monocytes total were 50 and 90 mg/head, respectively compared to 10 mg/head level. Total lymphocyte of 90 mg/head increased compared to level 10 and 50 mg/head. The highest total neutrophil as found at level of 50 mg/head which increased compared to the level of 0 and 10 mg/head. ProvisioningA. cordifolialeaf extract at doses level of 50 and 90 mg/head could increase litter size (P<0.05; χ2=9.267 and decreased offspring mortality (P<0.05; χ2=6.4. In conclusion, by giving 50 mg/head A. cordifolia leaf extract could increase leucocyte profile and offspring production of guinea pig.

  2. Mystacial Whisker Layout and Musculature in the Guinea Pig (Cavia porcellus): A Social, Diurnal Mammal.

    Science.gov (United States)

    Grant, Robyn A; Delaunay, Mariane G; Haidarliu, Sebastian

    2017-03-01

    All mammals (apart from apes and humans) have whiskers that make use of a similar muscle arrangement. Whisker specialists, such as rats and mice, tend to be nocturnal and arboreal, relying on their whisker sense of touch to guide exploration around tree canopies at night. As such, nocturnal arboreal rodents have many whiskers that are organised into a grid-like pattern, and moved using a complex array of muscles. Indeed, most arboreal, nocturnal mammals tend to have specialised whiskers that are longer and arranged in a dense, regular grid, compared with terrestrial, diurnal mammals. The guinea pig diverged early from murid rodents (around 75 million years ago), and are ground-dwelling, diurnal animals. It would be predicted that, as a terrestrial mammal, they may have less whiskers and a reduced muscle architecture compared to arboreal, nocturnal rodents. We examined the mystacial whisker layout, musculature and movement capacity of Guinea pig (Cavia porcellus) whiskers and found that they did indeed have a disorganized whisker layout, with a fortification around the eye area. In addition, there was a reduction in musculature, especially in the intrinsic muscles. Despite guinea pigs not cyclically moving their whiskers, the mystacial musculature was still very similar to that of murid rodents. We suggest that the conserved presence of whisker layout and musculature, even in visual mammals such as primates and guinea pigs, may indicate that whiskers still play an important role in these animals, including protecting the eyes and being involved in tactile social behaviors. Anat Rec, 300:527-536, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Validation of a Behavioral Ethogram for Assessing Postoperative Pain in Guinea Pigs (Cavia porcellus).

    Science.gov (United States)

    Dunbar, Misha L; David, Emily M; Aline, Marian R; Lofgren, Jennifer L

    2016-01-01

    Although guinea pigs (Cavia porcellus) have been used in research for more than a century and remain the most prevalent USDA-covered species, little has been elucidated regarding the recognition of clinical pain or analgesic efficacy in this species. We sought to assess pain in guinea pigs by using newer, clinically relevant methods that have been validated in other rodent species: the behavioral ethogram and cageside proxy indicator. In this study, 10 male guinea pigs underwent electronic von Frey testing of nociception, remote videorecording of behavior, and cageside assessment by using time-to-consumption (TTC) of a preferred treat test. These assessments were performed across 2 conditions (anesthesia only and castration surgery under anesthesia) at 3 time points (2, 8, and 24 h after the event). The anesthesia only condition served to control for the nonpainful but potentially distressing components of the surgical experience. Compared with those after anesthesia only conditions, subtle body movements were increased and nociceptive thresholds were decreased at 2 and 8 h after surgery. At 24 h, neither subtle body movement behaviors nor nociceptive thresholds differed between the 2 conditions. In contrast, TTC scores did not differ between the anesthesia only and surgery conditions at any time point, underscoring the challenge of identifying pain in this species through cageside evaluation. By comparing ethogram scores with measures of nociception, we validated select behaviors as pain-specific. Therefore, our novel ethogram allowed us to assess postoperative pain and may further serve as a platform for future analgesia efficacy studies in guinea pigs.

  4. Female novelty and the courtship behavior of male guinea pigs (Cavia porcellus

    Directory of Open Access Journals (Sweden)

    Cohn D.W.H.

    2004-01-01

    Full Text Available In several rodent species, an increase or recovery of sexual behavior can be observed when sexually satiated males are placed in contact with a novel mate. In order to assess the influence of female novelty on the courtship behavior of guinea pigs (Cavia porcellus, four adult males were observed during four daily 15-min sessions while interacting with the same pregnant female (same-female sessions. A new female was presented during the fifth session (switched-female session. The duration of behavioral categories was obtained from videotape records using an observational software. From the first to the second session, all males decreased the time allocated to investigating (sniffing and licking, following, and mounting the female, and that response did not recover by the end of the same-female sessions. No similar decreasing tendencies were detected in the circling or rumba categories. A marked increase of investigating occurred in all males from the last same-female session (8.1, 11.9, 15.1 and 17.3 percent session time to the switched-female one (16.4, 18.4, 37.1 and 28.9 percent session time, respectively. Increases in following and circling were recorded in three of four males, and full-blown recovery of mounting in one male. No consistent changes in the females' responses to males (following or attacking were observed throughout testing. These results are consistent with the hypothesis that guinea pig males recognize individual females and that courtship responses may suffer a habituation/recovery process controlled by mate novelty.

  5. Trixacarus caviae Fain, Howell & Hyatt 1972 (Acari: Sarcoptidae) as a cause of mange in guinea-pigs and papular urticaria in man

    NARCIS (Netherlands)

    Dorrestein, G.M.; Bronswijk, J.E.M.H. van

    1979-01-01

    The clinical symptoms of infestation with Trixacarus caviae in guinea-pigs are described. In general large areas of thickened, denuded skin, with a heavy secondary bacterial infection, and sometimes neurological signs, are observed in mangy cases. Antiparasitic therapy was successful with one or

  6. Variability in spectrophotometric pyruvate analyses for predicting onion pungency and nutraceutical value.

    Science.gov (United States)

    Beretta, Vanesa H; Bannoud, Florencia; Insani, Marina; Galmarini, Claudio R; Cavagnaro, Pablo F

    2017-06-01

    Onion pyruvate concentration is used as a predictor of flavor intensity and nutraceutical value. The protocol of Schwimmer and Weston (SW) (1961) is the most widespread methodology for estimating onion pyruvate. Anthon and Barret (AB) (2003) proposed modifications to this procedure. Here, we compared these spectrophotometry-based procedures for pyruvate analysis using a diverse collection of onion cultivars. The SW method always led to over-estimation of pyruvate levels in colored, but not in white onions, by up to 65%. Identification of light-absorbance interfering compounds was performed by spectrophotometry and HPLC analysis. Interference by quercetin and anthocyanins, jointly, accounted for more than 90% of the over-estimation of pyruvate. Pyruvate determinations according to AB significantly reduced absorbance interference from compounds other than pyruvate. This study provides evidence about the mechanistic basis underlying differences between the SW and AB methods for indirect assessment of onion flavor and nutraceutical value. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Optic neuropathy in a patient with pyruvate dehydrogenase deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Small, Juan E. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Gonzalez, Guido E. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States); Clinica Alemana de Santiago, Departmento de Imagenes, Santiago (Chile); Nagao, Karina E.; Walton, David S. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Ophthalmology, Boston, MA (United States); Caruso, Paul A. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2009-10-15

    Pyruvate dehydrogenase (PDH) deficiency is a genetic disorder of mitochondrial metabolism. The clinical manifestations range from severe neonatal lactic acidosis to chronic neurodegeneration. Optic neuropathy is an uncommon clinical sequela and the imaging findings of optic neuropathy in these patients have not previously been described. We present a patient with PDH deficiency with bilateral decreased vision in whom MRI demonstrated bilateral optic neuropathy and chiasmopathy. (orig.)

  8. Increased superoxide accumulation in pyruvate dehydrogenase complex deficient fibroblasts.

    Science.gov (United States)

    Glushakova, Lyudmyla G; Judge, Sharon; Cruz, Alex; Pourang, Deena; Mathews, Clayton E; Stacpoole, Peter W

    2011-11-01

    The pyruvate dehydrogenase complex (PDC) oxidizes pyruvate to acetyl CoA and is critically important in maintaining normal cellular energy homeostasis. Loss-of-function mutations in PDC give rise to congenital lactic acidosis and to progressive cellular energy failure. However, the subsequent biochemical consequences of PDC deficiency that may contribute to the clinical manifestations of the disorder are poorly understood. We postulated that altered flux through PDC would disrupt mitochondrial electron transport, resulting in oxidative stress. Compared to cells from 4 healthy subjects, primary cultures of skin fibroblasts from 9 patients with variable mutations in the gene encoding the alpha subunit (E1α) of pyruvate dehydrogenase (PDA1) demonstrated reduced growth and viability. Superoxide (O(2)(.-)) from the Qo site of complex III of the electron transport chain accumulated in these cells and was associated with decreased activity of manganese superoxide dismutase. The expression of uncoupling protein 2 was also decreased in patient cells, but there were no significant changes in the expression of cellular markers of protein or DNA oxidative damage. The expression of hypoxia transcription factor 1 alpha (HIF1α) also increased in PDC deficient fibroblasts. We conclude that PDC deficiency is associated with an increase in O(2)(.-) accumulation coupled to a decrease in mechanisms responsible for its removal. Increased HIF1α expression may contribute to the increase in glycolytic flux and lactate production in PDC deficiency and, by trans-activating pyruvate dehydrogenase kinase, may further suppress residual PDC activity through phosphorylation of the E1α subunit. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. PDK4 Inhibits Cardiac Pyruvate Oxidation in Late Pregnancy.

    Science.gov (United States)

    Liu, Laura X; Rowe, Glenn C; Yang, Steven; Li, Jian; Damilano, Federico; Chan, Mun Chun; Lu, Wenyun; Jang, Cholsoon; Wada, Shogo; Morley, Michael; Hesse, Michael; Fleischmann, Bernd K; Rabinowitz, Joshua D; Das, Saumya; Rosenzweig, Anthony; Arany, Zoltan

    2017-12-08

    Pregnancy profoundly alters maternal physiology. The heart hypertrophies during pregnancy, but its metabolic adaptations, are not well understood. To determine the mechanisms underlying cardiac substrate use during pregnancy. We use here 13 C glucose, 13 C lactate, and 13 C fatty acid tracing analyses to show that hearts in late pregnant mice increase fatty acid uptake and oxidation into the tricarboxylic acid cycle, while reducing glucose and lactate oxidation. Mitochondrial quantity, morphology, and function do not seem altered. Insulin signaling seems intact, and the abundance and localization of the major fatty acid and glucose transporters, CD36 (cluster of differentiation 36) and GLUT4 (glucose transporter type 4), are also unchanged. Rather, we find that the pregnancy hormone progesterone induces PDK4 (pyruvate dehydrogenase kinase 4) in cardiomyocytes and that elevated PDK4 levels in late pregnancy lead to inhibition of PDH (pyruvate dehydrogenase) and pyruvate flux into the tricarboxylic acid cycle. Blocking PDK4 reverses the metabolic changes seen in hearts in late pregnancy. Taken together, these data indicate that the hormonal environment of late pregnancy promotes metabolic remodeling in the heart at the level of PDH, rather than at the level of insulin signaling. © 2017 American Heart Association, Inc.

  10. Cold lability of pyruvate, orthophosphate dikinase in the maize leaf.

    Science.gov (United States)

    Shirahashi, K; Hayakawa, S; Sugiyama, T

    1978-11-01

    Cold lability of pyruvate, orthophosphate dikinase was investigated using a homogeneous, purified enzyme preparation from maize (Zea mays L. var. Golden Cross Bantam T51) leaves. Its stability was markedly reduced below about 10 C and the rate of cold inactivation followed first order kinetics at a concentration lower than about 0.1 milligram of enzyme per milliliter. Cold inactivation was little affected by pH in the range which gives good stability for the enzyme at warm temperatures and the enzyme activity was protected strongly by inclusion of substrates (pyruvate and phosphoenolpyruvate) and polyols such as sucrose, sorbitol, and glycerol. Loss of catalytic activity was accompanied by an apparent dissociation of a tetrameric form of the enzyme (9S form) into a new, more slowly sedimenting (5.1S) component. Inclusion of pyruvate at 4 mM in the cold-treated enzyme had no effect on the sedimentation value. A sharp change in activation energy of the dikinase-catalyzed reaction was observed near 12 C and its break point appears to be close to the generally accepted critical low temperature limit for the growth of maize plants.

  11. Therapeutic Targeting of the Pyruvate Dehydrogenase Complex/Pyruvate Dehydrogenase Kinase (PDC/PDK) Axis in Cancer.

    Science.gov (United States)

    Stacpoole, Peter W

    2017-11-01

    The mitochondrial pyruvate dehydrogenase complex (PDC) irreversibly decarboxylates pyruvate to acetyl coenzyme A, thereby linking glycolysis to the tricarboxylic acid cycle and defining a critical step in cellular bioenergetics. Inhibition of PDC activity by pyruvate dehydrogenase kinase (PDK)-mediated phosphorylation has been associated with the pathobiology of many disorders of metabolic integration, including cancer. Consequently, the PDC/PDK axis has long been a therapeutic target. The most common underlying mechanism accounting for PDC inhibition in these conditions is post-transcriptional upregulation of one or more PDK isoforms, leading to phosphorylation of the E1α subunit of PDC. Such perturbations of the PDC/PDK axis induce a "glycolytic shift," whereby affected cells favor adenosine triphosphate production by glycolysis over mitochondrial oxidative phosphorylation and cellular proliferation over cellular quiescence. Dichloroacetate is the prototypic xenobiotic inhibitor of PDK, thereby maintaining PDC in its unphosphorylated, catalytically active form. However, recent interest in the therapeutic targeting of the PDC/PDK axis for the treatment of cancer has yielded a new generation of small molecule PDK inhibitors. Ongoing investigations of the central role of PDC in cellular energy metabolism and its regulation by pharmacological effectors of PDKs promise to open multiple exciting vistas into the biochemical understanding and treatment of cancer and other diseases. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Effets de Panicum maximum Jacq. associé à Euphorbia heterophylla (L.) Klotz. & Garcke sur la productivité des femelles durant le cycle de reproduction chez le cobaye (Cavia porcellus L.)

    OpenAIRE

    N'G. D.V. Kouakou; Thys, E.; Yapi, YM.; Assidjo, EN.; Marnet, PG.; Grongnet, JF.

    2015-01-01

    Effect of Panicum maximum Jacq. Associated with Euphorbia heterophylla (L.) Klotz. & Garcke on Productivity of Females (Cavia porcellus L) During the Reproductive Cycle. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L.) are mainly fed with Panicum maximum Jacq. The association of this forage with Euphorbia heterophylla (L.) Klotz. & Garcke improves the organic matter digestibility of the mixed diet compared to P. maximum distributed alone in growing male guinea pigs. In order t...

  13. Pyruvate Dehydrogenase Kinase as a Novel Therapeutic Target in Oncology

    Directory of Open Access Journals (Sweden)

    Gopinath eSutendra

    2013-03-01

    Full Text Available Current drug development in oncology is non-selective as it typically focuses on pathways essential for the survival of all dividing cells. The unique metabolic profile of cancer, which is characterized by increased glycolysis and suppressed mitochondrial glucose oxidation provides cancer cells with a proliferative advantage, conducive with apoptosis resistance and even increased angiogenesis. Recent evidence suggests that targeting the cancer-specific metabolic and mitochondrial remodeling may offer selectivity in cancer treatment. Pyruvate dehydrogenase kinase (PDK is a mitochondrial enzyme that is activated in a variety of cancers and results in the selective inhibition of pyruvate dehydrogenase (PDH, a complex of enzymes that converts cytosolic pyruvate to mitochondrial acetyl-CoA, the substrate for the Krebs’ cycle. Inhibition of PDK with either small interfering RNAs or the orphan drug dichloroacetate (DCA shifts the metabolism of cancer cells from glycolysis to glucose oxidation and reverses the suppression of mitochondria-dependent apoptosis. In addition, this therapeutic strategy increases the production of diffusible Krebs’ cycle intermediates and mitochondria-derived reactive oxygen species (mROS, activating p53 or inhibiting pro-proliferative and pro-angiogenic transcription factors like nuclear factor of activated T-cells (NFAT and hypoxia-inducible factor 1α (HIF1α. These effects result in decreased tumor growth and angiogenesis in a variety of cancers with high selectivity. In a small but mechanistic clinical trial in patients with glioblastoma, a highly aggressive and vascular form of brain cancer, DCA decreased tumor angiogenesis and tumor growth, suggesting that metabolic targeting therapies can be translated directly to patients. Therefore, reversing the mitochondrial suppression with metabolic-modulating drugs, like PDK inhibitors holds promise in the rapidly expanding field of metabolic oncology.

  14. Simultaneous investigation of cardiac pyruvate dehydrogenase flux, Krebs cycle metabolism and pH, using hyperpolarized [1,2-(13)C2]pyruvate in vivo.

    Science.gov (United States)

    Chen, Albert P; Hurd, Ralph E; Schroeder, Marie A; Lau, Angus Z; Gu, Yi-ping; Lam, Wilfred W; Barry, Jennifer; Tropp, James; Cunningham, Charles H

    2012-02-01

    (13)C MR spectroscopy studies performed on hearts ex vivo and in vivo following perfusion of prepolarized [1-(13)C]pyruvate have shown that changes in pyruvate dehydrogenase (PDH) flux may be monitored non-invasively. However, to allow investigation of Krebs cycle metabolism, the (13)C label must be placed on the C2 position of pyruvate. Thus, the utilization of either C1 or C2 labeled prepolarized pyruvate as a tracer can only afford a partial view of cardiac pyruvate metabolism in health and disease. If the prepolarized pyruvate molecules were labeled at both C1 and C2 positions, then it would be possible to observe the downstream metabolites that were the results of both PDH flux ((13)CO(2) and H(13)CO(3)(-)) and Krebs cycle flux ([5-(13)C]glutamate) with a single dose of the agent. Cardiac pH could also be monitored in the same experiment, but adequate SNR of the (13)CO(2) resonance may be difficult to obtain in vivo. Using an interleaved selective RF pulse acquisition scheme to improve (13)CO(2) detection, the feasibility of using dual-labeled hyperpolarized [1,2-(13)C(2)]pyruvate as a substrate for dynamic cardiac metabolic MRS studies to allow simultaneous investigation of PDH flux, Krebs cycle flux and pH, was demonstrated in vivo. Copyright © 2011 John Wiley & Sons, Ltd.

  15. Glutamate-pyruvate transaminase subtypes in Singapore ethnic groups.

    Science.gov (United States)

    Saha, N; Bhattacharyya, S P

    1989-01-01

    Autopsy liver samples from 244 Chinese, 119 Malays and 136 Indians were screened for glutamate-pyruvate transaminase (GPT) subtypes by starch-gel electrophoresis and isoelectric focusing at pH 5-7. Altogether, ten phenotypes controlled by four alleles (GPT1, GPT2A, GPT2B and GPT3) were identified. There was no significant difference in the frequency of GPT alleles between the ethnic groups. The distribution of GPT types was in agreement with the Hardy-Weinberg equilibrium in all the ethnic groups.

  16. A comparative analysis of the intestinal metagenomes present in guinea pigs (Cavia porcellus) and humans (Homo sapiens)

    DEFF Research Database (Denmark)

    Hildebrand, Falk; Ebersbach, Tine; Nielsen, Henrik Bjørn

    2012-01-01

    the guinea pig microbiome to existing human gut metagenome data from the MetaHIT project. Results: We found that the bacterial richness obtained for human samples was lower than for guinea pig samples. The intestinal microbiotas of both species were dominated by the two phyla Bacteroidetes and Firmicutes......Background: Guinea pig (Cavia porcellus) is an important model for human intestinal research. We have characterized the faecal microbiota of 60 guinea pigs using Illumina shotgun metagenomics, and used this data to compile a gene catalogue of its prevalent microbiota. Subsequently, we compared......, but at genus level, the majority of identified genera (320 of 376) were differently abundant in the two hosts. For example, the guinea pig contained considerably more of the mucin-degrading Akkermansia, as well as of the methanogenic archaea Methanobrevibacter than found in humans. Most microbiome functional...

  17. Pyruvate Accumulation Is the First Line of Cell Defense against Heat Stress in a Fungus.

    Science.gov (United States)

    Zhang, Xing; St Leger, Raymond J; Fang, Weiguo

    2017-09-05

    Heat tolerance is well known to be key to fungal survival in many habitats, but our mechanistic understanding of how organisms adapt to heat stress is still incomplete. Using Metarhizium robertsii , an emerging model organism for assessing evolutionary processes, we report that pyruvate is in the vanguard of molecules that scavenge heat-induced reactive oxygen species (ROS). We show that, as well as inducing a rapid burst of ROS production, heat stress also downregulates genes for pyruvate consumption. The accumulating pyruvate is the fastest acting of several M. robertsii ROS scavengers, efficiently reducing protein carbonylation, stabilizing mitochondrial membrane potential, and promoting fungal growth. The acetate produced from pyruvate-ROS reactions itself causes acid stress, tolerance to which is regulated by Hog1 mitogen-activated protein kinase. Heat stress also induces pyruvate accumulation in several other fungi, suggesting that scavenging of heat-induced ROS by pyruvate is widespread. IMPORTANCE Heat is a dangerous challenge for most organisms, as it denatures proteins and induces the production of ROS that inactivate proteins, lipid membranes, and DNA. How organisms respond to this stress is not fully understood. Using the experimentally tractable insect pathogen Metarhizium robertsii as a model organism, we show for the first time that heat stress induces pyruvate production and that this functions as the first line of defense against heat-induced ROS. Heat stress also induces rapid pyruvate accumulation in other fungi, suggesting that pyruvate is a common but unappreciated defense against stress. Copyright © 2017 Zhang et al.

  18. Binding of ethyl pyruvate to bovine serum albumin: Calorimetric, spectroscopic and molecular docking studies

    Energy Technology Data Exchange (ETDEWEB)

    Pathak, Mallika [Department of Chemistry, Miranda House, University of Delhi, Delhi 11007 (India); Mishra, Rashmi; Agarwala, Paban K. [Department of Radiation Genetics and Epigenetics, Division of Radioprotective Drug Development Research, Institute of Nuclear Medicine and Allied Sciences, Delhi 110054 (India); Ojha, Himanshu, E-mail: himanshu.drdo@gmail.com [Department of Radiation Genetics and Epigenetics, Division of Radioprotective Drug Development Research, Institute of Nuclear Medicine and Allied Sciences, Delhi 110054 (India); Singh, Bhawna [Department of Radiation Genetics and Epigenetics, Division of Radioprotective Drug Development Research, Institute of Nuclear Medicine and Allied Sciences, Delhi 110054 (India); Singh, Anju; Kukreti, Shrikant [Nucleic Acid Research Laboratory, Department of Chemistry, University of Delhi, Delhi 11007 (India)

    2016-06-10

    Highlights: • ITC study showed binding of ethyl pyruvate with BSA with high binding affinity. • Ethyl pyruvate binding caused conformation alteration of BSA. • Fluorescence quenching mechanism is static in nature. • Electrostatic, hydrogen bonding and hydrophobic forces involved in binding. • Docking confirmed role of electrostatic, hydrogen bonding and hydrophobic forces. - Abstract: Various in vitro and in vivo studies have shown the anti-inflammatory and anticancer potential role of ethyl pyruvate. Bio-distribution of drugs is significantly influenced by the drug-serum protein binding. Therefore, the binding mechanism of the ethyl pyruvate with bovine serum albumin was investigated using UV–vis absorption, fluorescence, circular dichroism, isothermal titration calorimetry and molecular docking techniques. Absorption and fluorescence quenching studies indicated the binding of ethyl pyruvate with protein. Circular dichroism spectra of bovine serum albumin confirmed significant change in the conformation of protein upon binding. Thermodynamic data confirmed that ethyl pyruvate binds to bovine serum albumin at the two different sites with high affinity. Binding of ethyl pyruvate to bovine serum albumin involves hydrogen bonding, van der Waal and hydrophobic interactions. Further, docking studies indicated that ethyl pyruvate could bind significantly at the three binding sites. The results will definitely contribute to the development of ethyl pyruvate as drug.

  19. Pyruvate carboxylase deficiency: An underestimated cause of lactic acidosis

    Directory of Open Access Journals (Sweden)

    F. Habarou

    2015-03-01

    Full Text Available Pyruvate carboxylase (PC is a biotin-containing mitochondrial enzyme that catalyzes the conversion of pyruvate to oxaloacetate, thereby being involved in gluconeogenesis and in energy production through replenishment of the tricarboxylic acid (TCA cycle with oxaloacetate. PC deficiency is a very rare metabolic disorder. We report on a new patient affected by the moderate form (the American type A. Diagnosis was nearly fortuitous, resulting from the revision of an initial diagnosis of mitochondrial complex IV (C IV defect. The patient presented with severe lactic acidosis and pronounced ketonuria, associated with lethargy at age 23 months. Intellectual disability was noted at this time. Amino acids in plasma and organic acids in urine did not show patterns of interest for the diagnostic work-up. In skin fibroblasts PC showed no detectable activity whereas biotinidase activity was normal. We had previously reported another patient with the severe form of PC deficiency and we show that she also had secondary C IV deficiency in fibroblasts. Different anaplerotic treatments in vivo and in vitro were tested using fibroblasts of both patients with 2 different types of PC deficiency, type A (patient 1 and type B (patient 2. Neither clinical nor biological effects in vivo and in vitro were observed using citrate, aspartate, oxoglutarate and bezafibrate. In conclusion, this case report suggests that the moderate form of PC deficiency may be underdiagnosed and illustrates the challenges raised by energetic disorders in terms of diagnostic work-up and therapeutical strategy even in a moderate form.

  20. Pyruvate kinase M2: a potential target for regulating inflammation

    Directory of Open Access Journals (Sweden)

    Jose Carlos eAlves-Filho

    2016-04-01

    Full Text Available Pyruvate kinase (PK is the enzyme responsible for catalyzing the last step of glycolysis. Of the four PK isoforms expressed in mammalian cells, PKM2 has generated the most interest due to its impact on changes in cellular metabolism observed in cancer as well as in activated immune cells. As our understanding of dysregulated metabolism in cancer develops, and in light of the growing field of immunometabolism, intense efforts are in place to define the mechanism by which PKM2 regulates the metabolic profile of cancer as well as of immune cells. The enzymatic activity of PKM2 is heavily regulated by endogenous allosteric effectors as well as by intracellular signalling pathways, affecting both the enzymatic activity of PKM2 as a pyruvate kinase and the regulation of the recently described non-canonical nuclear functions of PKM2. We here review the current literature on PKM2 and its regulation, and discuss the potential for PKM2 as a therapeutic target in inflammatory and metabolic disorders.

  1. Breeding of guinea-pig (Cavia porcellus, L. 1758) for meat production in Butembo, Democratic Republic of Congo : Literature review and breeding scheme

    OpenAIRE

    Sikiminywa, K.-L.; Godeau, Jean-Marie; Nyongombe, U.-F.; Hornick, Jean-Luc

    2013-01-01

    Providing animal proteins to humans requires choosing the animal species to be raised when access to land is limited. Butembo, is a refuge city of conflicts area in the east of Democratic Republic of Congo, where guinea-pig (Cavia porcellus) is considered as food. Therefore the breeding of this animal is an option to make more meat available. Genetic selection of guinea pigs and popularization of improved farming techniques can contribute to solve problems of food security in the region. The ...

  2. Directed evolution of pyruvate decarboxylase-negative Saccharomyces cerevisiae, yielding a C2-independent, glucose-tolerant, and pyruvate-hyperproducing yeast

    NARCIS (Netherlands)

    A.J. van Maris; J.M. Geertman; A. Vermeulen; M.K. Groothuizen; A.A. Winkler; M.D. Piper; J.P. van Dijken; J.T. Pronk

    2004-01-01

    textabstractThe absence of alcoholic fermentation makes pyruvate decarboxylase-negative (Pdc(-)) strains of Saccharomyces cerevisiae an interesting platform for further metabolic engineering of central metabolism. However, Pdc(-) S. cerevisiae strains have two growth defects:

  3. High-field dissolution dynamic nuclear polarization of [1-13C]pyruvic acid

    DEFF Research Database (Denmark)

    Yoshihara, Hikari A. I.; Can, Emine; Karlsson, Magnus

    2016-01-01

    [1-13C]pyruvate is the most widely used hyperpolarized metabolic magnetic resonance imaging agent. Using a custom-built 7.0 T polarizer operating at 1.0 K and trityl radical-doped [1-13C]pyruvic acid, unextrapolated solution-state 13C polarization greater than 60% was measured after dissolution a...

  4. Prebiotic synthesis of phosphoenol pyruvate by α-phosphorylation-controlled triose glycolysis

    Science.gov (United States)

    Coggins, Adam J.; Powner, Matthew W.

    2017-04-01

    Phosphoenol pyruvate is the highest-energy phosphate found in living organisms and is one of the most versatile molecules in metabolism. Consequently, it is an essential intermediate in a wide variety of biochemical pathways, including carbon fixation, the shikimate pathway, substrate-level phosphorylation, gluconeogenesis and glycolysis. Triose glycolysis (generation of ATP from glyceraldehyde 3-phosphate via phosphoenol pyruvate) is among the most central and highly conserved pathways in metabolism. Here, we demonstrate the efficient and robust synthesis of phosphoenol pyruvate from prebiotic nucleotide precursors, glycolaldehyde and glyceraldehyde. Furthermore, phosphoenol pyruvate is derived within an α-phosphorylation controlled reaction network that gives access to glyceric acid 2-phosphate, glyceric acid 3-phosphate, phosphoserine and pyruvate. Our results demonstrate that the key components of a core metabolic pathway central to energy transduction and amino acid, sugar, nucleotide and lipid biosyntheses can be reconstituted in high yield under mild, prebiotically plausible conditions.

  5. Pyruvate modifies metabolic flux and nutrient sensing during extracorporeal membrane oxygenation in an immature swine model

    Energy Technology Data Exchange (ETDEWEB)

    Ledee, Dolena R.; Kajimoto, Masaki; O' Kelly-Priddy, Colleen M.; Olson, Aaron; Isern, Nancy G.; Robillard Frayne, Isabelle; Des Rosiers, Christine; Portman, Michael A.

    2015-07-01

    Extracorporeal membrane oxygenation (ECMO) provides mechanical circulatory support for infants and children with postoperative cardiopulmonary failure. Nutritional support is mandatory during ECMO, although specific actions for substrates on the heart have not been delineated. Prior work shows that enhancing pyruvate oxidation promotes successful weaning from ECMO. Accordingly, we closely examined the role of prolonged systemic pyruvate supplementation in modifying metabolic parameters during the unique conditions of ventricular unloading provided by ECMO. Twelve male mixed breed Yorkshire piglets (age 30-49 days) received systemic infusion of either normal saline (Group C) or pyruvate (Group P) during ECMO for 8 hours. Over the final hour piglets received [2-13C] pyruvate, and [13C6]-L-leucine, as an indicator for oxidation and protein synthesis. A significant increase in lactate and pyruvate concentrations occurred, along with an increase in the absolute concentration of all measured CAC intermediates. Group P showed greater anaplerotic flux through pyruvate carboxylation although pyruvate oxidation relative to citrate synthase flux was similar to Group C. The groups demonstrated similar leucine fractional contributions to acetyl-CoA and fractional protein synthesis rates. Pyruvate also promoted an increase in the phosphorylation state of several nutrient sensitive enzymes, such as AMPK and ACC, and promoted O-GlcNAcylation through the hexosamine biosynthetic pathway (HBP). In conclusion, prolonged pyruvate supplementation during ECMO modified anaplerotic pyruvate flux and elicited changes in important nutrient and energy sensitive pathways, while preserving protein synthesis. Therefore, the observed results support the further study of nutritional supplementation and its downstream effects on cardiac adaptation during ventricular unloading.

  6. The Crystal Structure of Toxoplasma gondii Pyruvate Kinase 1

    Energy Technology Data Exchange (ETDEWEB)

    Bakszt, R.; Wernimont, A; Allali-Hassani, A; Mok, M; Hills, T; Hui, R; Pizarro, J

    2010-01-01

    Pyruvate kinase (PK), which catalyzes the final step in glycolysis converting phosphoenolpyruvate to pyruvate, is a central metabolic regulator in most organisms. Consequently PK represents an attractive therapeutic target in cancer and human pathogens, like Apicomplexans. The phylum Aplicomplexa, a group of exclusively parasitic organisms, includes the genera Plasmodium, Cryptosporidium and Toxoplasma, the etiological agents of malaria, cryptosporidiosis and toxoplasmosis respectively. Toxoplasma gondii infection causes a mild illness and is a very common infection affecting nearly one third of the world's population. We have determined the crystal structure of the PK1 enzyme from T. gondii, with the B domain in the open and closed conformations. We have also characterized its enzymatic activity and confirmed glucose-6-phosphate as its allosteric activator. This is the first description of a PK enzyme in a closed inactive conformation without any bound substrate. Comparison of the two tetrameric TgPK1 structures indicates a reorientation of the monomers with a concomitant change in the buried surface among adjacent monomers. The change in the buried surface was associated with significant B domain movements in one of the interacting monomers. We hypothesize that a loop in the interface between the A and B domains plays an important role linking the position of the B domain to the buried surface among monomers through two {alpha}-helices. The proposed model links the catalytic cycle of the enzyme with its domain movements and highlights the contribution of the interface between adjacent subunits. In addition, an unusual ordered conformation was observed in one of the allosteric binding domains and it is related to a specific apicomplexan insertion. The sequence and structural particularity would explain the atypical activation by a mono-phosphorylated sugar. The sum of peculiarities raises this enzyme as an emerging target for drug discovery.

  7. Endoparasitos em cobaias (Cavia porcellus (Mammalia, Rodentia, Caviidae provenientes de biotérios de criação e experimentação do município do Rio de Janeiro, Brasil Endoparasites in guinea pigs (Cavia porcellus (Mammalia, Rodentia, Caviidae from breeding and experimentation animal housing of the municipality of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Luciana Casartelli Alves

    2007-10-01

    Full Text Available Foi realizado um levantamento sobre a prevalência e intensidade de infecção de endoparasitos em cobaias convencionais de linhagem Short Hair provenientes de biotérios de criação (A e experimentação (B do município do Rio de Janeiro, Brasil, avaliando-se a eficácia das medidas de prevenção entre eles. Para a realização do estudo, utilizou-se exame direto de mucosa e do conteúdo intestinal, a técnica de tricromo de WHEATLEY e exames coproparasitológicos pelas técnicas de Ritchie e Kinyoun. Os parasitos encontrados através da técnica de exame direto da mucosa e do conteúdo intestinal e de tricromo de WHEATLEY com as respectivas prevalências foram: Balantidium sp. (78%, Cyathodinium sp. (68%, Eimeria caviae (38%, Paraspidodera uncinata (34% e Giardia muris (24%. Nos exames de fezes realizados pelas técnicas de Ritchie e Kinyoun, foram encontrados os seguintes parasitos com as respectivas prevalências no biotério A: E. caviae (74%, Balantidium sp. (68%, Cyathodinium sp. (68% e Cryptosporidium sp. (5%. No biotério B, observou-se: E. caviae (58%, Balantidium sp. (42%, Cyathodinium sp. (25% e G. muris (8%. A alta prevalência de endoparasitos nos biotérios sugere a necessidade de se rever a eficácia das barreiras sanitárias adotadas.This paper discusses the prevalence and intensity of infection of endoparasites in conventionally maintained Short Hair guinea pigs colonies from a breeding (A and an experimental (B facilities in Rio de Janeiro, Brazil. It also evaluates the efficacy of the methods of prevention adopted by both facilities. The search of parasites was performed by direct examination of intestinal mucosa and its contents, WHEATLEY's trichrome method and coproparasitological examinations by Ritchie's and Kinyoun's techniques. The prevalences of endoparasites found throught direct examination of intestinal mucosa and its contents were: Balantidium sp. (78%, Cyathodinium sp. (68%, Eimeria caviae (38%, Paraspidodera

  8. Pyruvate metabolism: A therapeutic opportunity in radiation-induced skin injury

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyun; Kang, Jeong Wook [Department of Radiation Oncology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Lee, Dong Won [Department of Plastic Surgery, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Oh, Sang Ho [Department of Dermatology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Lee, Yun-Sil [College of Pharmacy & Division of Life and Pharmaceutical Sciences, Ewah Womans University, Seoul 120-750 (Korea, Republic of); Lee, Eun-Jung [Department of Radiation Oncology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Cho, Jaeho, E-mail: jjhmd@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)

    2015-05-08

    Ionizing radiation is used to treat a range of cancers. Despite recent technological progress, radiation therapy can damage the skin at the administration site. The specific molecular mechanisms involved in this effect have not been fully characterized. In this study, the effects of pyruvate, on radiation-induced skin injury were investigated, including the role of the pyruvate dehydrogenase kinase 2 (PDK2) signaling pathway. Next generation sequencing (NGS) identified a wide range of gene expression differences between the control and irradiated mice, including reduced expression of PDK2. This was confirmed using Q-PCR. Cell culture studies demonstrated that PDK2 overexpression and a high cellular pyruvate concentration inhibited radiation-induced cytokine expression. Immunohistochemical studies demonstrated radiation-induced skin thickening and gene expression changes. Oral pyruvate treatment markedly downregulated radiation-induced changes in skin thickness and inflammatory cytokine expression. These findings indicated that regulation of the pyruvate metabolic pathway could provide an effective approach to the control of radiation-induced skin damage. - Highlights: • The effects of radiation on skin thickness in mice. • Next generation sequencing revealed that radiation inhibited pyruvate dehydrogenase kinase 2 expression. • PDK2 inhibited irradiation-induced cytokine gene expression. • Oral pyruvate treatment markedly downregulated radiation-induced changes in skin thickness.

  9. Single pyruvate intake induces blood alkalization and modification of resting metabolism in humans.

    Science.gov (United States)

    Olek, Robert A; Luszczyk, Marcin; Kujach, Sylwester; Ziemann, Ewa; Pieszko, Magdalena; Pischel, Ivo; Laskowski, Radoslaw

    2015-03-01

    Three separate studies were performed with the aim to 1) determine the effect of a single sodium pyruvate intake on the blood acid-base status in males and females; 2) compare the effect of sodium and calcium pyruvate salts and establish their role in the lipolysis rate; and 3) quantify the effect of single pyruvate intake on the resting energy metabolism. In all, 48 individuals completed three separate studies. In all the studies, participants consumed a single dose of pyruvate 0.1 g/kg 60 min before commencing the measurements. The whole blood pH, bicarbonate concentration, base excess or plasma glycerol, free fatty acids, glucose concentrations, or resting energy expenditure and calculated respiratory exchange ratio were determined. The analysis of variance for repeated measurements was performed to examine the interaction between treatment and time. The single dose of sodium pyruvate induced blood alkalization, which was more marked in the male than in the female participants. Following the ingestion of sodium or calcium pyruvate, the blood acid-base parameters were higher than in the placebo trial. Furthermore, 3-h postingestion glycerol was lower in both pyruvate trials than in placebo. Resting energy expenditure did not differ between the trials; however, carbohydrate oxidation was increased after sodium pyruvate ingestion. Pyruvate intake induced mild alkalization in a sex-dependent fashion. Moreover, it accelerated carbohydrate metabolism and delayed the rate of glycerol appearance in the blood, but had no effect on the resting energy expenditure. Furthermore, sodium salt seems to have had a greater effect on the blood buffering level than calcium salt. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. [Simple method of acetoid determination and its application to the analysis of pyruvate dehydrogenase].

    Science.gov (United States)

    Vovk, A I; Parkhomenko, Iu M; Babicheva, A F; Chernysh, I Iu

    1982-01-01

    A modification of the method for determining the content of acetoin in biological media is described; the method is based on formation of a stained complex under acyloin heating with the acidified ammonium molybdate water solution. Colorimetric determination of the acetoin amount in the enzymic system containing sodium pyruvate, thiamine pyrophosphate and tris-HCl is shown to be possible. Application of the method to analysis of the catalytic activity of pyruvate dehydrogenase preparations from different sources and with different degree of purification in the reaction of acetoin formation from pyruvate is described.

  11. St. Lucia.

    Science.gov (United States)

    1987-06-01

    The population of St Lucia was 123,000 in 1986, with an annual growth rate of 2%. The infant mortality rate stands at 22.2/1000 live births, and life expectancy is 70.3 years for males and 74.9 years for females. The literacy rate is 78%. St Lucia's labor force is allocated as follows: agriculture, 36.6%; industry and commerce, 20.1%; and services, 18.1%. The gross national product (GNP) was US$146 million in 1985, with an annual growth rate of 3% and a per capita GNP of $1071. St Lucia is a parliamentary democracy modeled on the British Westminster system. The island is divided into 16 parishes and 1 urban area (the capital, Castries). St Lucia is currently a politically stable country, although the high level of youth unemployment is a cause for concern. Ongoing stability may depend on the government's ability to provide services such as jobs and housing. The economy has evolved from a monocrop sugar plantation type to a diversified economy based on agriculture, industry, and tourism. Agriculture, dominated by the banana industry, is characterized by the participation of a large number of small and medium-sized enterprises. Industry is being encouraged through the provision of incentives such as tax rebates. The government is attempting to maintain a sound investment climate through a tripartite dialogue with the private sector and trade unions. Overall economic policy is predicated on the attraction of sound investments, by both local and foreign entities, to accelerate the rate of economic growth, solve the unemployment problem, and generate a solid balance-of-payments position.

  12. Effect of chest wall radiotherapy in different manners using tissue equivalent bolus on skin and lung of cavia cobayas

    International Nuclear Information System (INIS)

    Huang Wei; Qu Yaqin; Song Xiangfu; Liu Shixin; Jia Xiaojing; Guo He; Yang Lei

    2009-01-01

    Objective: To probe the influence of electron beam radiotherapy in different manners using different tissue equivalent boluses on skin and lung. Methods: Adult female cavia cobayas were randomly divided into four groups as control group, half-time with bolus group, half-time with bolus group and without bolus group. Acute-irradiation animal models were established using electron beam in different manners with or without 0.5 cm tissue equivalent bolus. Pathological changes in lung, hair vesicle and fibroblast cell count were analyzed 40 clays after irradiation. Results: The radiation dermatitis in the group with bolus was slighter than that of the group without bolus, but the radiation pneumonia was reverse. With bolus, the radiation dermatitis of haft-time group was slighter than that of full-time group. The injury repair of half-time group was more active than full-time group. Conclusions: The treatment of haft-time bolus could protect lung without serious skin complications. (authors)

  13. Evaluation of the infectivity and the persistence of Trichinella patagoniensis in muscle tissue of decomposing guinea pig (Cavia porcellus).

    Science.gov (United States)

    Fariña, F; Pasqualetti, M; Ilgová, J; Cardillo, N; Ercole, M; Aronowicz, T; Krivokapich, S; Kašný, M; Ribicich, M

    2017-01-01

    Trichinella patagoniensis, a new species of Trichinella, is widespread in Argentina. The success of parasite transmission depends, among other factors, on the resistance of L1 larvae present in the muscle tissue (ML) of dead hosts undergoing the decomposition process in different environmental conditions. The aim of the present work was to study the infectivity of T. patagoniensis muscle larvae in Cavia porcellus and the capability of the parasite to survive in decomposed muscle tissue of guinea pigs subjected to different environmental conditions. Thirty-two female Ssi:AL guinea pigs were orally inoculated with 2000 ML of T. patagoniensis (ISS2311). All the animals were sacrificed 42 days post-infection. Twenty-six animals were eviscerated, and carcasses were placed on the surface of soil inside plastic boxes that were exposed to environmental conditions in the summer 2014-2015 and autumn of 2015 in Buenos Aires, Argentina. Carcasses from six animals were placed into a plastic box inside the refrigerator at a temperature of 4 °C. The muscle tissue samples from the carcasses were examined weekly for the presence of larvae, and the infectivity of recovered ML was tested in BALB/c mice. Our results showed for the first time the ability of T. patagoniensis to complete its life cycle in guinea pigs, thus serving as a potential natural host. Also, larvae of T. patagoniensis remained infective in muscle tissue for several weeks while undergoing decomposition under different environmental conditions.

  14. Evaluating the clinical and physiological effects of long term ultraviolet B radiation on guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Watson, Megan K; Stern, Adam W; Labelle, Amber L; Joslyn, Stephen; Fan, Timothy M; Leister, Katie; Kohles, Micah; Marshall, Kemba; Mitchell, Mark A

    2014-01-01

    Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (pguinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended.

  15. Hyperendemic Campylobacter jejuni in guinea pigs (Cavia porcellus) raised for food in a semi-rural community of Quito, Ecuador.

    Science.gov (United States)

    Graham, Jay P; Vasco, Karla; Trueba, Gabriel

    2016-06-01

    Domestic animals and animal products are the source of pathogenic Campylobacter jejuni and C. coli in industrialized countries, yet little is known about the transmission of these bacteria in developing countries. Guinea pigs (Cavia porcellus) are commonly raised for food in the Andean region of South America, however, limited research has characterized this rodent as a reservoir of zoonotic enteric pathogens. In this study, we examined the prevalence of Campylobacter spp. in 203 fecal samples from domestic animals of 59 households in a semi-rural parish of Quito, Ecuador. Of the twelve animal species studied, guinea pigs showed the highest prevalence of C. jejuni (n = 39/40; 97.5%). Multilocus sequence typing (MLST) was used to characterize the genetic relationship of C. jejuni from domestic animals and 21 sequence types (STs) were identified. The majority of STs from guinea pigs appeared to form new clonal complexes that were not related to STs of C. jejuni isolated from other animal species and shared only a few alleles with other C. jejuni previously characterized. The study identifies guinea pigs as a major reservoir of C. jejuni and suggests that some C. jejuni strains are adapted to this animal species. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. GRAMÍNEAS TROPICALES EN EL ENGORDE DE CUYES MEJORADOS SEXADOS (Cavia porcellus Linnaeus EN LA ZONA DE LA MANÁ

    Directory of Open Access Journals (Sweden)

    Adolfo Sánchez Laiño

    2009-06-01

    Full Text Available La investigación de gramíneas tropicales en el engorde de cuyes en la zona de La Maná. La misma que persiguió los siguientes objetivos: Incrementar los índices productivos en cuyes (Cavia porcellus Linnaeus peruanos mejorados bajo el efecto del consumo del pasto saboya (Panicum maximun Jack, hojas de maíz (Zea mays y caña de azúcar (Saccharum officinarum L en la zona de La Maná, y determinar la rentabilidad de los tratamientos. Se utilizaron 48 cuyes peruanos mejorados sexados de 35 días de edad con un peso promedio de 305 g. Se aplicó un arreglo factorial 2 (sexo x 3 (gramíneas con cuatro repeticiones, dentro de un (DBCA. Para las comparaciones entre medidas se utilizó la prueba de Tukey al 0.05% de probabilidad. Para obtener la rentabilidad de los tratamientos se utilizó la Relación Beneficio–Costo. Se evaluó el: consumo de gramíneas (g, consumo de alimento (g, ganancia de peso (g, conversión alimenticia, peso vivo (g y rendimiento a la canal (%. Los cuyes machos presentaron el mayor (P0.05 no se vio afectado por el efecto del consumo de gramíneas. La mayor rentabilidad la registraron los cuyes machos alimentados con hoja de maíz + balanceado (52.4%.

  17. Changes in myocardial lactate, pyruvate and lactate-pyruvate ratio during cardiopulmonary bypass for elective adult cardiac surgery: Early indicator of morbidity

    Directory of Open Access Journals (Sweden)

    P M Kapoor

    2011-01-01

    Full Text Available Background: Myocardial lactate assays have been established as a standard method to compare various myocardial protection strategies. This study was designed to test whether coronary sinus (CS lactates, pyruvate and lactate-pyruvate (LP ratio correlates with myocardial dysfunction and predict postoperative outcomes. Materials and Methods: This prospective observational study was conducted on 40 adult patients undergoing elective cardiac surgery with the aid of cardiopulmonary bypass (CPB. CS blood sampling was done for estimation of myocardial lactate (ML, pyruvate (MP and lactate-pyruvate ratio (MLPR namely: pre-CPB (T 1 , after removal of aortic cross clamp (T 2 and 30 minutes post-CPB (T 3 . Results: Baseline myocardial LPR strongly correlated with Troponin-I at T1 (s: 0.6. Patients were sub grouped according to the median value of myocardial lactate (2.9 at baseline T1 into low myocardial lactate (LML group, mean (2.39±0.4 mmol/l, n=19 and a high myocardial lactate (HML group, mean (3.65±0.9 mmol/l, n=21. A significant increase in PL, ML, MLPR and TropI occurred in both groups as compared to baseline. Patients in HML group had significant longer period of ICU stay. Patients with higher inotrope score had significantly higher ML (T2, T3. ML with a baseline value of 2.9 mmol/l had 70.83% sensitivity and 62.5% specificity (ROC area: 0.7109 Std error: 0.09 while myocardial pyruvate with a baseline value of 0.07 mmol/l has 79.17% sensitivity and 68.75% specificity (ROC area: 0.7852, Std error: 0.0765 for predicting inotrope requirement after CPB. Conclusion: CS lactate, pyruvate and LP ratio correlate with myocardial function and can predict postoperative outcome.

  18. Phosphorylation of the pyruvate dehydrogenase complex isolated from Ascaris suum

    Energy Technology Data Exchange (ETDEWEB)

    Thissen, J.; Komuniecki, R.

    1987-05-01

    The pyruvate dehydrogenase complex (PDC) from body wall muscle of the porcine nematode, Ascaris suum, plays a pivotal role in anaerobic mitochondrial metabolism. As in mammalian mitochondria, PDC activity is inhibited by the phosphorylation of the ..cap alpha..PDH subunit, catalyzed by an associated PDH/sub a/ kinase. However, in contrast to PDC's isolated from all other eukaryotic sources, phosphorylation decreases the mobility of the ..cap alpha..PDH subunit on SDS-PAGE and permits the separation of the phosphorylated and nonphosphorylated ..cap alpha..PDH's. Phosphorylation and the inactivation of the Ascaris PDC correspond directly, and the additional phosphorylation that occurs after complete inactivation in mammalian PDC's is not observed. The purified ascarid PDC incorporates 10 nmoles /sup 32/P/mg P. Autoradiography of the radiolabeled PDC separated by SDS-PAGE yields a band which corresponds to the phosphorylated ..cap alpha..PDH and a second, faint band which is present only during the first three minutes of PDC inactivation, intermediate between the phosphorylated and nonphosphorylated ..cap alpha..PDH subunit. Tryptic digests of the /sup 32/P-PDC yields one major phosphopeptide, when separated by HPLC, and its amino acid sequence currently is being determined.

  19. A pyruvate-buffered dialysis fluid induces less peritoneal angiogenesis and fibrosis than a conventional solution

    NARCIS (Netherlands)

    van Westrhenen, Roos; Zweers, Machteld M.; Kunne, Cindy; de Waart, Dirk R.; van der Wal, Allard C.; Krediet, Raymond T.

    2008-01-01

    BACKGROUND: Conventional lactate-buffered peritoneal dialysis (PD) fluids containing glucose and glucose degradation products are believed to contribute to the development of fibrosis and angiogenesis in the dialyzed peritoneum. To reduce potential negative effects of lactate, pyruvate was

  20. Structural Biology of Proteins of the Multi-enzyme Assembly Human Pyruvate Dehydrogenase Complex

    Science.gov (United States)

    2003-01-01

    Objectives and research challenges of this effort include: 1. Need to establish Human Pyruvate Dehydrogenase Complex protein crystals; 2. Need to test value of microgravity for improving crystal quality of Human Pyruvate Dehydrogenase Complex protein crystals; 3. Need to improve flight hardware in order to control and understand the effects of microgravity on crystallization of Human Pyruvate Dehydrogenase Complex proteins; 4. Need to integrate sets of national collaborations with the restricted and specific requirements of flight experiments; 5. Need to establish a highly controlled experiment in microgravity with a rigor not yet obtained; 6. Need to communicate both the rigor of microgravity experiments and the scientific value of results obtained from microgravity experiments to the national community; and 7. Need to advance the understanding of Human Pyruvate Dehydrogenase Complex structures so that scientific and commercial advance is identified for these proteins.

  1. A Simple Experiment Demonstrating the Allosteric Regulation of Yeast Pyruvate Kinase.

    Science.gov (United States)

    Taber, Richard L.; Campbell, Angela; Spencer, Scott

    1998-01-01

    Explains the procedures used to determine the regulatory properties of yeast pyruvate kinase. Involves a partial purification using PEG precipitation that can be done in one laboratory period with simple equipment. (DDR)

  2. Relatedness of three species of "false neisseriae," Neisseria caviae, Neisseria cuniculi, and Neisseria ovis, by DNA-DNA hybridizations and fatty acid analysis.

    Science.gov (United States)

    Véron, M; Lenvoisé-Furet, A; Coustère, C; Ged, C; Grimont, F

    1993-04-01

    DNA-DNA hybridization was used to determine the levels of genomic relatedness of the three species of "false neisseriae," Neisseria caviae, Neisseria cuniculi, and Neisseria ovis. The reference strains of these species exhibited high levels of intraspecies relatedness (93 to 100% for N. caviae, 79 to 100% for N. cuniculi, and 68 to 100% for N. ovis) but low levels of interspecific relatedness (less than 34%) to each other and to various species belonging to the beta subclass of the Proteobacteria (Kingella kingae, Neisseria gonorrhoeae, Neisseria meningitidis, and Oligella urethralis) or to the gamma subclass (Branhamella catarrhalis, Kingella indologenes, Moraxella atlantae, Moraxella bovis, Moraxella lacunata subsp. lacunata, Moraxella lacunata subsp. liquefaciens, Moraxella nonliquefaciens, Moraxella osloensis, and Moraxella phenylpyruvica). However, the levels of DNA-DNA hybridization for the three species of "false neisseriae" were significantly higher with the species belonging to the gamma subclass (average, 13.7%) than with the species belonging to the beta subclass (average, 4.5%). These data suggest that N. caviae, N. cuniculi, and N. ovis are three separate genomic species in the gamma subclass. An ascendant hierarchical classification based only on fatty acid profiles distinguished four main classes containing (i) most of the "classical moraxellae," the "false neisseriae," and B. catarrhalis, (ii) only Acinetobacter spp., (iii) M. nonliquefaciens and "misnamed moraxellae" (M. atlantae, M. osloensis, and M. phenylpyruvica), and (iv) the "true neisseriae," the three Kingella species, and O. urethralis. Fatty acids that distinguish these four classes were identified. The fatty acid profiles of the two strains of Psychrobacter immobilis which we studied are not very similar to the profiles of the other taxa. Our results support the hypothesis that the three species of "false neisseriae," B. catarrhalis, the "classical moraxellae," and Acinetobacter spp

  3. Ethyl Pyruvate: An Anti-Microbial Agent that Selectively Targets Pathobionts and Biofilms

    OpenAIRE

    Debebe, Tewodros; Kr?ger, Monika; Huse, Klaus; Kacza, Johannes; M?hlberg, Katja; K?nig, Brigitte; Birkenmeier, Gerd

    2016-01-01

    The microbiota has a strong influence on health and disease in humans. A causative shift favoring pathobionts is strongly linked to diseases. Therefore, anti-microbial agents selectively targeting potential pathogens as well as their biofilms are urgently demanded. Here we demonstrate the impact of ethyl pyruvate, so far known as ROS scavenger and anti-inflammatory agent, on planktonic microbes and biofilms. Ethyl pyruvate combats preferably the growth of pathobionts belonging to bacteria and...

  4. Glutamic Pyruvate Transaminase GPT2 Promotes Tumorigenesis of Breast Cancer Cells by Activating Sonic Hedgehog Signaling

    OpenAIRE

    Cao, Yuan; Lin, Shu-Hai; Wang, Yongbin; Chin, Y. Eugene; Kang, Lan; Mi, Jun

    2017-01-01

    Increased glutamine metabolism is a hallmark of cancer. Mitochondrial glutamic pyruvate transaminase (GPT2) catalyzes the reversible transamination between alanine and ?-ketoglutarate (?-KG), also known as 2-oxoglutarate, to generate pyruvate and glutamate during cellular glutamine catabolism. However, the precise role of GPT2 in tumorigenesis remains elusive. Here, we report that in breast cancer tissue samples and breast cancer cell lines, GPT2 expression level was markedly elevated and cor...

  5. Ketogenic diet in pyruvate dehydrogenase complex deficiency: short- and long-term outcomes

    OpenAIRE

    Sofou, Kalliopi; Dahlin, Maria; Hallb??k, Tove; Lindefeldt, Marie; Viggedal, Gerd; Darin, Niklas

    2017-01-01

    Objectives Our aime was to study the short- and long-term effects of ketogenic diet on the disease course and disease-related outcomes in patients with pyruvate dehydrogenase complex deficiency, the metabolic factors implicated in treatment outcomes, and potential safety and compliance issues. Methods Pediatric patients diagnosed with pyruvate dehydrogenase complex deficiency in Sweden and treated with ketogenic diet were evaluated. Study assessments at specific time points included developme...

  6. Pyruvate incubation enhances glycogen stores and sustains neuronal function during subsequent glucose deprivation.

    Science.gov (United States)

    Shetty, Pavan K; Sadgrove, Matthew P; Galeffi, Francesca; Turner, Dennis A

    2012-01-01

    The use of energy substrates, such as lactate and pyruvate, has been shown to improve synaptic function when administered during glucose deprivation. In the present study, we investigated whether prolonged incubation with monocarboxylate (pyruvate or lactate) prior rather than during glucose deprivation can also sustain synaptic and metabolic function. Pyruvate pre-incubation(3-4h) significantly prolonged (>25 min) the tolerance of rat hippocampal slices to delayed glucose deprivation compared to control and lactate pre-incubated slices, as revealed by field excitatory post synaptic potentials (fEPSPs); pre-incubation with pyruvate also reduced the marked decrease in NAD(P)H fluorescence resulting from glucose deprivation. Moreover, pyruvate exposure led to the enhancement of glycogen stores with time, compared to glucose alone (12 μmol/g tissue at 4h vs. 3.5 μmol/g tissue). Prolonged resistance to glucose deprivation following exogenous pyruvate incubation was prevented by glycogenolysis inhibitors, suggesting that enhanced glycogen mediates the delay in synaptic activity failure. The application of an adenosine A1 receptor antagonist enhanced glycogen utilization and prolonged the time to synaptic failure, further confirming this hypothesis of the importance of glycogen. Moreover, tissue levels of ATP were also significantly maintained during glucose deprivation in pyruvate pretreated slices compared to control and lactate. In summary, these experiments indicate that pyruvate exposure prior to glucose deprivation significantly increased the energy buffering capacity of hippocampal slices, particularly by enhancing internal glycogen stores, delaying synaptic failure during glucose deprivation by maintaining ATP levels, and minimizing the decrease in the levels of NAD(P)H. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. RENDIMIENTO Y COMPOSICIÓN CORPORAL DE CUYES (CAVIA PORCELLUS) SUPLEMENTADOS CON TRES NIVELES DE HARINA DE SANGRE BOVINO (BOS TAURUS) PROCESADA ARTESANALMENTE

    OpenAIRE

    ZAMORA HUAMÁN, SEGUNDO JOSÉ

    2016-01-01

    This research aimed to evaluate the performance and body composition of Guinea pigs (Cavia porcellus) supplemented with three levels of bovine blood meal (Bos taurus) processed by hand in Small Animals Module of Chachapoyas Experimental Station of the Toribio Rodríguez of Mendoza of Amazonas National University. Food rations were evaluated in an iso energy and iso protein levels with 4%, 8% and 12% of blood meal, using 36 Guinea Pigs weaned males of 21 days of age, divided into groups of ...

  8. Untersuchungen zum Vorkommen von Ektoparasiten bei domestizierten und wildlebenden Meerschweinchen (Cavia spp.)sowie an präinkaischen Meerschweinchenmumien in Peru, Südamerika

    OpenAIRE

    Dittmar de la Cruz, Katharina

    2004-01-01

    7. Zusammenfassung Untersuchungen zu Vorkommen von Ektoparasiten bei domestizierten und wildlebenden Meerschweinchen (Cavia spp.) sowie an präinkaischen Meerschweinchenmumien in Peru, Südamerika Dittmar de la Cruz, Katharina Institut für Parasitologie, Veterinärmedizinische Fakultät, Universität Leipzig (120 Seiten, 29 Tabellen, 67 Abbildungen, 187 Literaturangaben, 3 Anhänge) In den Zeiträumen von Dezember 1996 bis Februar 1997 und Februar bis Oktober 1998 sowie im Mai 1999 wurden Untersuchu...

  9. Enriquecimiento de la Carne de Cuy (Cavia porcellus) con Ácidos Grasos Omega-3 Mediante Dietas con Aceite de Pescado y Semillas de Sacha Inchi (Plukenetia volubilis)

    OpenAIRE

    Guevara V., Jorge; Escuela Académica Profesional de Ingeniería Agroindustrial, Universidad Nacional Mayor de San Marcos, Lima; Rojas M., Sergio; Departamento de Nutrición, Facultad de Zootecnia, Universidad Nacional Agraria La Molina, Lima; Carcelén C., Fernando; Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Seminario S., Luis; Universidad de Concepción, Chillán

    2016-01-01

    El objetivo del estudio fue enriquecer la carne de cuy (Cavia porcellus) con ácidos grasos omega-3 mediante el uso de dietas con fuentes de omega-3. Se utilizaron 48 cuyes machos de 42 días de edad y peso inicial de 615 g. Los cuyes se asignaron al azar a cuatro tratamientos con tres repeticiones (pozas) de cuatro cuyes cada una. Los tratamientos fueron: 1) Dieta control; 2) Dieta suplementada con 1.0% de aceite de pescado; 3) Dieta suplementada con 4.0% de semilla de sacha inchi (Plukenetia ...

  10. Caracterización Fenotípica y Molecular del Agente Causal de Salmonelosis en Cuyes (Cavia porcellus) de Arequipa

    OpenAIRE

    Manrique Meza Jorge Ernesto

    2010-01-01

    La bacteria Salmonella spp. es un importante agente etiológico de enfermedades transmitidas por alimentos (ETA) al hombre por contaminación de huevos, carne, leche y derivados cárnicos y lácticos. Así mismo, causa altas tasas de morbilidad y mortalidad en la crianza de la especie Cavia porcellus (cuyes). Su detección en alimentos y en centros de crianza de cuyes, previene brotes y permite implementar controles de vigilancia epidemiológica de la enfermedad. Los métodos fenotípic...

  11. Pyruvate dehydrogenase kinase inhibition: Reversing the Warburg effect in cancer therapy

    Directory of Open Access Journals (Sweden)

    Hayden Bell

    2016-06-01

    Full Text Available The poor efficacy of many cancer chemotherapeutics, which are often non-selective and highly toxic, is attributable to the remarkable heterogeneity and adaptability of cancer cells. The Warburg effect describes the up regulation of glycolysis as the main source of adenosine 5’-triphosphate in cancer cells, even under normoxic conditions, and is a unique metabolic phenotype of cancer cells. Mitochondrial suppression is also observed which may be implicated in apoptotic suppression and increased funneling of respiratory substrates to anabolic processes, conferring a survival advantage. The mitochondrial pyruvate dehydrogenase complex is subject to meticulous regulation, chiefly by pyruvate dehydrogenase kinase. At the interface between glycolysis and the tricarboxylic acid cycle, the pyruvate dehydrogenase complex functions as a metabolic gatekeeper in determining the fate of glucose, making pyruvate dehydrogenase kinase an attractive candidate in a bid to reverse the Warburg effect in cancer cells. The small pyruvate dehydrogenase kinase inhibitor dichloroacetate has, historically, been used in conditions associated with lactic acidosis but has since gained substantial interest as a potential cancer chemotherapeutic. This review considers the Warburg effect as a unique phenotype of cancer cells in-line with the history of and current approaches to cancer therapies based on pyruvate dehydrogenase kinase inhibition with particular reference to dichloroacetate and its derivatives.

  12. Pyruvate Decarboxylase Activity Assay in situ of Different Industrial Yeast Strains

    Directory of Open Access Journals (Sweden)

    Dorota Kręgiel

    2009-01-01

    Full Text Available Cytoplasmic pyruvate decarboxylase (PDC, EC 4.1.1.1 is one of the key enzymes of yeast fermentative metabolism. PDC is the first enzyme which, under anaerobic conditions, leads to decarboxylation of pyruvate with acetaldehyde as the end product. The aim of this study is to develop a suitable method for PDC activity assay in situ for different industrial yeast strains. Saccharomyces sp. and Debaryomyces sp. yeast strains grew in fermentative medium with 12 % of glucose. Enzymatic assay was conducted in cell suspension treated with digitonin as permeabilisation agent, and with sodium pyruvate as a substrate, at temperature of 30 °C. Metabolites of PDC pathway were detected using gas chromatographic (GC technique. Various parameters like type and molar concentration of the substrate, minimal effective mass fraction of digitonin, cell concentration, reaction time and effect of pyrazole (alcohol dehydrogenase inhibitor were monitored to optimize PDC enzymatic assay in situ. In the concentration range of yeast cells from 1⋅10^7 to 1⋅10^8 per mL, linear correlation between the produced acetaldehyde and cell density was noticed. Only pyruvate was the specific substrate for pyruvate decarboxylase. In the presence of 0.05 M sodium pyruvate and 0.05 % digitonin, the enzymatic reaction was linear up to 20 min of the assay. During incubation, there was no formation of ethanol and, therefore, pyrazole was not necessary for the assay.

  13. Use of recombinant human thyroid-stimulating hormone for evaluation of thyroid function in guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Mayer, Jörg; Wagner, Robert; Mitchell, Mark A; Fecteau, Kellie

    2013-02-01

    To evaluate the effects of administration of recombinant human (rh) thyroid-stimulating hormone (TSH) for evaluation of thyroid function in euthyroid guinea pigs (Cavia porcellus). Prospective, experimental study. 10 healthy, sexually intact, pet guinea pigs (approx 1 year of age). Guinea pigs were given rhTSH (100 μg, IM); plasma thyroxine concentrations were determined prior to and 3 and 4 hours after rhTSH injection. The animals were housed in 2 groups on the basis of sex and fed different commercial maintenance diets according to their husbandry. There was no significant difference in thyroxine concentrations between males and females before or after rhTSH injection. There was also no difference between thyroxine concentrations at 3 versus 4 hours after rhTSH injection. There was a significant difference between thyroxine concentrations before (median, 9.05 nmol/L [0.70 μg/dL]; 10% to 90% range, 7.39 to 16.99 nmol/L [0.57 to 1.32 μg/dL]) and after (mean ± SD, 23.95 ± 4.2 nmol/L) rhTSH injection. Euthyroid guinea pigs had plasma thyroxine concentrations of at least 7.30 nmol/L (0.57 μg/dL) and an increase of at least 2.6 times prestimulation thyroxine concentrations at 3 or 4 hours after stimulation. The results suggested that rhTSH administered IM can be used for the TSH stimulation testing in guinea pigs. We suggest thyroxine concentration in a euthyroid guinea pig should at least double 3 to 4 hours after rhTSH injection.

  14. New Insights on the Mechanism of the K+-Independent Activity of Crenarchaeota Pyruvate Kinases

    Science.gov (United States)

    De la Vega-Ruíz, Gustavo; Domínguez-Ramírez, Lenin; Riveros-Rosas, Héctor; Guerrero-Mendiola, Carlos; Torres-Larios, Alfredo; Hernández-Alcántara, Gloria; García-Trejo, José J.; Ramírez-Silva, Leticia

    2015-01-01

    Eukarya pyruvate kinases have glutamate at position 117 (numbered according to the rabbit muscle enzyme), whereas in Bacteria have either glutamate or lysine and in Archaea have other residues. Glutamate at this position makes pyruvate kinases K+-dependent, whereas lysine confers K+-independence because the positively charged residue substitutes for the monovalent cation charge. Interestingly, pyruvate kinases from two characterized Crenarchaeota exhibit K+-independent activity, despite having serine at the equivalent position. To better understand pyruvate kinase catalytic activity in the absence of K+ or an internal positive charge, the Thermofilum pendens pyruvate kinase (valine at the equivalent position) was characterized. The enzyme activity was K+-independent. The kinetic mechanism was random order with a rapid equilibrium, which is equal to the mechanism of the rabbit muscle enzyme in the presence of K+ or the mutant E117K in the absence of K+. Thus, the substrate binding order of the T. pendens enzyme was independent despite lacking an internal positive charge. Thermal stability studies of this enzyme showed two calorimetric transitions, one attributable to the A and C domains (Tm of 99.2°C), and the other (Tm of 105.2°C) associated with the B domain. In contrast, the rabbit muscle enzyme exhibits a single calorimetric transition (Tm of 65.2°C). The calorimetric and kinetic data indicate that the B domain of this hyperthermophilic enzyme is more stable than the rest of the protein with a conformation that induces the catalytic readiness of the enzyme. B domain interactions of pyruvate kinases that have been determined in Pyrobaculum aerophilum and modeled in T. pendens were compared with those of the rabbit muscle enzyme. The results show that intra- and interdomain interactions of the Crenarchaeota enzymes may account for their higher B domain stability. Thus the structural arrangement of the T. pendens pyruvate kinase could allow charge

  15. Ethyl Pyruvate Ameliorates Hepatic Ischemia-Reperfusion Injury by Inhibiting Intrinsic Pathway of Apoptosis and Autophagy

    Directory of Open Access Journals (Sweden)

    Miao Shen

    2013-01-01

    Full Text Available Background. Hepatic ischemia-reperfusion (I/R injury is a pivotal clinical problem occurring in many clinical conditions such as transplantation, trauma, and hepatic failure after hemorrhagic shock. Apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. Ethyl pyruvate, a stable and simple lipophilic ester, has been shown to have anti-inflammatory properties. In this study, the purpose is to explore both the effect of ethyl pyruvate on hepatic I/R injury and regulation of intrinsic pathway of apoptosis and autophagy. Methods. Three doses of ethyl pyruvate (20 mg/kg, 40 mg/kg, and 80 mg/kg were administered 1 h before a model of segmental (70% hepatic warm ischemia was established in Balb/c mice. All serum and liver tissues were obtained at three different time points (4 h, 8 h, and 16 h. Results. Alanine aminotransferase (ALT, aspartate aminotransferase (AST, and pathological features were significantly ameliorated by ethyl pyruvate (80 mg/kg. The expression of Bcl-2, Bax, Beclin-1, and LC3, which play an important role in the regulation of intrinsic pathway of apoptosis and autophagy, was also obviously decreased by ethyl pyruvate (80 mg/kg. Furthermore, ethyl pyruvate inhibited the HMGB1/TLR4/ NF-κb axis and the release of cytokines (TNF-α and IL-6. Conclusion. Our results showed that ethyl pyruvate might attenuate to hepatic I/R injury by inhibiting intrinsic pathway of apoptosis and autophagy, mediated partly through downregulation of HMGB1/TLR4/ NF-κb axis and the competitive interaction with Beclin-1 of HMGB1.

  16. Assessing the transport rate of hyperpolarized pyruvate and lactate from the intra- to the extracellular space.

    Science.gov (United States)

    Reineri, Francesca; Daniele, Valeria; Cavallari, Eleonora; Aime, Silvio

    2016-08-01

    The use of [1-(13) C]pyruvate hyperpolarized by means of dynamic nuclear polarization provides a direct way to track the metabolic transformations of this metabolite in vivo and in cell cultures. The identification of the intra- and extracellular contributions to the (13) C NMR resonances is not straightforward. In order to obtain information about the rate of pyruvate and lactate transport through the cellular membrane, we set up a method that relies on the sudden 'quenching' of the extracellular metabolites' signal. The paramagnetic Gd-tetraazacyclododecane triacetic acid (Gd-DO3A) complex was used to dramatically decrease the longitudinal relaxation time constants of the (13) C-carboxylate resonances of both pyruvate and lactate. When Gd-DO3A was added to an MCF-7 cellular culture, which had previously received a dose of hyperpolarized [1-(13) C]pyruvate, the contributions of the extracellular pyruvate and lactate signals were deleted. From the analysis of the decay curves of the (13) C-carboxylate resonances of pyruvate and lactate it was possible to extract information about the exchange rate of the two metabolites across the cellular membrane. In particular, it was found that, in the reported experimental conditions, the lactate transport from the intra- to the extracellular space is not much lower than the rate of lactate formation. The method reported herein is non-destructive and it could be translated to in vivo studies. It opens a route for the use of hyperpolarized pyruvate to assess altered activity of carboxylate transporter proteins that may occur in pathological conditions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Chronic pyruvate supplementation increases exploratory activity and brain energy reserves in young and middle-aged mice

    DEFF Research Database (Denmark)

    Koivisto, Hennariikka; Leinonen, Henri; Puurula, Mari

    2016-01-01

    to brain and thereby attenuate aging- or AD-related cognitive impairment. Mice received ~800 mg/kg/day Na-pyruvate in their chow for 2-6 months. In middle-aged wild-type mice and in 6.5-month-old APP/PS1 mice, pyruvate facilitated spatial learning and increased exploration of a novel odor. However......, and found no effects. Metabolic postmortem assays revealed increased energy compounds in nuclear magnetic resonance spectroscopy as well as increased brain glycogen storages in the pyruvate group. Pyruvate supplementation may counteract aging-related behavioral impairment, but its beneficial effect seems......, in passive avoidance task for fear memory, the treatment group was clearly impaired. Independent of age, long-term pyruvate increased explorative behavior, which likely explains the paradoxical impairment in passive avoidance. We also assessed pyruvate effects on body weight, muscle force, and endurance...

  18. Physiological functions of pyruvate:NADP+oxidoreductase and 2-oxoglutarate decarboxylase in Euglena gracilis under aerobic and anaerobic conditions.

    Science.gov (United States)

    Nakazawa, Masami; Hayashi, Ryuta; Takenaka, Shigeo; Inui, Hiroshi; Ishikawa, Takahiro; Ueda, Mitsuhiro; Sakamoto, Tatsuji; Nakano, Yoshihisa; Miyatake, Kazutaka

    2017-07-01

    In Euglena gracilis, pyruvate:NADP + oxidoreductase, in addition to the pyruvate dehydrogenase complex, functions for the oxidative decarboxylation of pyruvate in the mitochondria. Furthermore, the 2-oxoglutarate dehydrogenase complex is absent, and instead 2-oxoglutarate decarboxylase is found in the mitochondria. To elucidate the central carbon and energy metabolisms in Euglena under aerobic and anaerobic conditions, physiological significances of these enzymes involved in 2-oxoacid metabolism were examined by gene silencing experiments. The pyruvate dehydrogenase complex was indispensable for aerobic cell growth in a glucose medium, although its activity was less than 1% of that of pyruvate:NADP + oxidoreductase. In contrast, pyruvate:NADP + oxidoreductase was only involved in the anaerobic energy metabolism (wax ester fermentation). Aerobic cell growth was almost completely suppressed when the 2-oxoglutarate decarboxylase gene was silenced, suggesting that the tricarboxylic acid cycle is modified in Euglena and 2-oxoglutarate decarboxylase takes the place of the 2-oxoglutarate dehydrogenase complex in the aerobic respiratory metabolism.

  19. Metabolic responses to pyruvate kinase deletion in lysine producing Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Wittmann Christoph

    2008-03-01

    Full Text Available Abstract Background Pyruvate kinase is an important element in flux control of the intermediate metabolism. It catalyzes the irreversible conversion of phosphoenolpyruvate into pyruvate and is under allosteric control. In Corynebacterium glutamicum, this enzyme was regarded as promising target for improved production of lysine, one of the major amino acids in animal nutrition. In pyruvate kinase deficient strains the required equimolar ratio of the two lysine precursors oxaloacetate and pyruvate can be achieved through concerted action of the phosphotransferase system (PTS and phosphoenolpyruvate carboxylase (PEPC, whereby a reduced amount of carbon may be lost as CO2 due to reduced flux into the tricarboxylic acid (TCA cycle. In previous studies, deletion of pyruvate kinase in lysine-producing C. glutamicum, however, did not yield a clear picture and the exact metabolic consequences are not fully understood. Results In this work, deletion of the pyk gene, encoding pyruvate kinase, was carried out in the lysine-producing strain C. glutamicum lysCfbr, expressing a feedback resistant aspartokinase, to investigate the cellular response to deletion of this central glycolytic enzyme. Pyk deletion was achieved by allelic replacement, verified by PCR analysis and the lack of in vitro enzyme activity. The deletion mutant showed an overall growth behavior (specific growth rate, glucose uptake rate, biomass yield which was very similar to that of the parent strain, but differed in slightly reduced lysine formation, increased formation of the overflow metabolites dihydroxyacetone and glycerol and in metabolic fluxes around the pyruvate node. The latter involved a flux shift from pyruvate carboxylase (PC to PEPC, by which the cell maintained anaplerotic supply of the TCA cycle. This created a metabolic by-pass from PEP to pyruvate via malic enzyme demonstrating its contribution to metabolic flexibility of C. glutamicum on glucose. Conclusion The metabolic

  20. EFFECT OF TYPE B BOTULINAL TOXIN ON THE LEVEL OF PYRUVIC ACID IN TISSUES OF GUINEA PIGS,

    Science.gov (United States)

    CLOSTRIDIUM BOTULINUM, TOXINS AND ANTITOXINS), PYRUVIC ACID, TISSUES(BIOLOGY), CENTRAL NERVOUS SYSTEM, MUSCLES, BLOOD, TOXICITY, GUINEA PIGS , CARBON DIOXIDE, METABOLISM, RESPIRATION, MORPHOLOGY(BIOLOGY), USSR

  1. The mitochondrial pyruvate carrier mediates high fat diet-induced increases in hepatic TCA cycle capacity.

    Science.gov (United States)

    Rauckhorst, Adam J; Gray, Lawrence R; Sheldon, Ryan D; Fu, Xiaorong; Pewa, Alvin D; Feddersen, Charlotte R; Dupuy, Adam J; Gibson-Corley, Katherine N; Cox, James E; Burgess, Shawn C; Taylor, Eric B

    2017-11-01

    Excessive hepatic gluconeogenesis is a defining feature of type 2 diabetes (T2D). Most gluconeogenic flux is routed through mitochondria. The mitochondrial pyruvate carrier (MPC) transports pyruvate from the cytosol into the mitochondrial matrix, thereby gating pyruvate-driven gluconeogenesis. Disruption of the hepatocyte MPC attenuates hyperglycemia in mice during high fat diet (HFD)-induced obesity but exerts minimal effects on glycemia in normal chow diet (NCD)-fed conditions. The goal of this investigation was to test whether hepatocyte MPC disruption provides sustained protection from hyperglycemia during long-term HFD and the differential effects of hepatocyte MPC disruption on TCA cycle metabolism in NCD versus HFD conditions. We utilized long-term high fat feeding, serial measurements of postabsorptive blood glucose and metabolomic profiling and 13 C-lactate/ 13 C-pyruvate tracing to investigate the contribution of the MPC to hyperglycemia and altered hepatic TCA cycle metabolism during HFD-induced obesity. Hepatocyte MPC disruption resulted in long-term attenuation of hyperglycemia induced by HFD. HFD increased hepatic mitochondrial pyruvate utilization and TCA cycle capacity in an MPC-dependent manner. Furthermore, MPC disruption decreased progression of fibrosis and levels of transcript markers of inflammation. By contributing to chronic hyperglycemia, fibrosis, and TCA cycle expansion, the hepatocyte MPC is a key mediator of the pathophysiology induced in the HFD model of T2D. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  2. Role of flavin in acetoin production by two bacterial pyruvate oxidases.

    Science.gov (United States)

    Bertagnolli, B L; Hager, L P

    1993-01-01

    Escherichia coli pyruvate oxidase (POXEC) requires FAD both for the oxidative decarboxylation of pyruvate to acetate and CO2 and for the formation of acetoin from pyruvate and acetaldehyde. Prior work has shown that the catalytic activity (kcat/Km) for POXEC in the oxidative reaction is stimulated approximately 450-fold by amphiphilic activators. This paper shows that the acetoin reaction does not respond to activation. The FAD requirement for acetoin formation can be replaced by 5-deaza-FAD and 6-hydroxy-FAD, FAD analogs which form kinetically stable oxidized and reduced enzyme species, respectively. As would be expected, the 5-deaza- and 6-hydroxy-FAD enzymes are not active in the oxidative reaction. A second flavin pyruvate oxidase from Pediococcus pseudomonas (POXPP), which catalyzes the oxidative decarboxylation of pyruvate to CO2 and acetyl phosphate, also requires FAD for acetoin formation. POXPP has an oxidative rate comparable to that of POXEC, but in comparison to POXEC, POXPP catalyzes acetoin formation at a much reduced rate. Again, as was found with the POXEC, an FAD analog incapable of undergoing facile oxidation-reduction reactions also could replace the FAD requirement in the POXPP acetoin reaction. The results indicate that the role for FAD in acetoin formation with both enzymes is based on a structural requirement and that FAD does not participate in a redox function in the acetoin reaction.

  3. Role of pyruvate metabolism in the growth of Streptococcus faecalis in the presence of propionate.

    Science.gov (United States)

    Kamihara, T

    1969-01-01

    The growth of Streptococcus faecalis is inhibited by propionate, and the inhibition is reversed by lipoic acid or acetate. A study of the role of pyruvate oxidation in S. faecalis showed that propionate inhibited the lipoic acid-dependent aerobic oxidation of pyruvate in resting cells. Pyruvate dehydrogenation with neotetrazolium as a hydrogen acceptor in cell-free extracts also required lipoic acid and was markedly inhibited by propionyl phosphate as well as sodium propionate. Some lipid substances, such as palmitate, oleate, behenate, and lecithin, had a lipoic acid-replacing effect on growth of the organism. Biotin or bicarbonate promoted the lipoic acid-dependent growth. Acetate-2-(14)C added to the medium was mainly incorporated into the lipid fraction of the cells. Evolution of (14)CO(2) from pyruvate-2-(14)C was not observed in resting cells of the organism, even under aerobic conditions. From the above findings, it is concluded that lipid synthesis through pyruvate oxidation plays a very important role in bacterial growth in medium containing propionate.

  4. Ethyl Pyruvate: An Anti-Microbial Agent that Selectively Targets Pathobionts and Biofilms.

    Science.gov (United States)

    Debebe, Tewodros; Krüger, Monika; Huse, Klaus; Kacza, Johannes; Mühlberg, Katja; König, Brigitte; Birkenmeier, Gerd

    The microbiota has a strong influence on health and disease in humans. A causative shift favoring pathobionts is strongly linked to diseases. Therefore, anti-microbial agents selectively targeting potential pathogens as well as their biofilms are urgently demanded. Here we demonstrate the impact of ethyl pyruvate, so far known as ROS scavenger and anti-inflammatory agent, on planktonic microbes and biofilms. Ethyl pyruvate combats preferably the growth of pathobionts belonging to bacteria and fungi independent of the genera and prevailing drug resistance. Surprisingly, this anti-microbial agent preserves symbionts like Lactobacillus species. Moreover, ethyl pyruvate prevents the formation of biofilms and promotes matured biofilms dissolution. This potentially new anti-microbial and anti-biofilm agent could have a tremendous positive impact on human, veterinary medicine and technical industry as well.

  5. Ethyl Pyruvate: An Anti-Microbial Agent that Selectively Targets Pathobionts and Biofilms.

    Directory of Open Access Journals (Sweden)

    Tewodros Debebe

    Full Text Available The microbiota has a strong influence on health and disease in humans. A causative shift favoring pathobionts is strongly linked to diseases. Therefore, anti-microbial agents selectively targeting potential pathogens as well as their biofilms are urgently demanded. Here we demonstrate the impact of ethyl pyruvate, so far known as ROS scavenger and anti-inflammatory agent, on planktonic microbes and biofilms. Ethyl pyruvate combats preferably the growth of pathobionts belonging to bacteria and fungi independent of the genera and prevailing drug resistance. Surprisingly, this anti-microbial agent preserves symbionts like Lactobacillus species. Moreover, ethyl pyruvate prevents the formation of biofilms and promotes matured biofilms dissolution. This potentially new anti-microbial and anti-biofilm agent could have a tremendous positive impact on human, veterinary medicine and technical industry as well.

  6. Compartmentalized activities of the pyruvate dehydrogenase complex sustain lipogenesis in prostate cancer.

    Science.gov (United States)

    Chen, Jingjing; Guccini, Ilaria; Mitri, Diletta Di; Brina, Daniela; Revandkar, Ajinkya; Sarti, Manuela; Pasquini, Emiliano; Alajati, Abdullah; Pinton, Sandra; Losa, Marco; Civenni, Gianluca; Catapano, Carlo V; Sgrignani, Jacopo; Cavalli, Andrea; D'Antuono, Rocco; Asara, John M; Morandi, Andrea; Chiarugi, Paola; Crotti, Sara; Agostini, Marco; Montopoli, Monica; Masgras, Ionica; Rasola, Andrea; Garcia-Escudero, Ramon; Delaleu, Nicolas; Rinaldi, Andrea; Bertoni, Francesco; Bono, Johann de; Carracedo, Arkaitz; Alimonti, Andrea

    2018-02-01

    The mechanisms by which mitochondrial metabolism supports cancer anabolism remain unclear. Here, we found that genetic and pharmacological inactivation of pyruvate dehydrogenase A1 (PDHA1), a subunit of the pyruvate dehydrogenase complex (PDC), inhibits prostate cancer development in mouse and human xenograft tumor models by affecting lipid biosynthesis. Mechanistically, we show that in prostate cancer, PDC localizes in both the mitochondria and the nucleus. Whereas nuclear PDC controls the expression of sterol regulatory element-binding transcription factor (SREBF)-target genes by mediating histone acetylation, mitochondrial PDC provides cytosolic citrate for lipid synthesis in a coordinated manner, thereby sustaining anabolism. Additionally, we found that PDHA1 and the PDC activator pyruvate dehydrogenase phosphatase 1 (PDP1) are frequently amplified and overexpressed at both the gene and protein levels in prostate tumors. Together, these findings demonstrate that both mitochondrial and nuclear PDC sustain prostate tumorigenesis by controlling lipid biosynthesis, thus suggesting this complex as a potential target for cancer therapy.

  7. THE COUPLED REDOX POTENTIAL OF THE LACTATE-ENZYME-PYRUVATE SYSTEM

    Science.gov (United States)

    Baumberger, J. Percy; Jürgensen, J. J.; Bardwell, Kathleen

    1933-01-01

    1. The term "coupled redox potential" is defined. 2. The system lactic ion See PDF for Equation pyruvic ion + 2H+ + 2e is shown to be reversible (when the enzyme is lactic acid dehydrogenase) and its coupled redox potential between pH 5.2 and 7.2 at 32°C. is: See PDF for Equation 3. The free energy of the reaction: lactic ion (1m) → pyruvic ion (1m) = -ΔF = –14,572. 4. The standard free energy of formation (ΔF 298) of pyruvic acid (l) is estimated at –108,127. This is merely an approximation as some necessary data are lacking. 5. The importance of coupled redox potentials as a factor in the regulation of the equilibrium of metabolites is indicated. PMID:19872753

  8. A new synthesis of [3-11C]pyruvic acid using alanine racemase

    International Nuclear Information System (INIS)

    Ikemoto, M.; Okamoto, E.; Sasaki, M.; Haradahira, T.; Omura, H.; Furuya, Y.; Suzuki, K.; Watanabe, Y.

    1998-01-01

    The synthesis of [3- 11 C]pyruvic acid was attempted by two reaction systems (A: alanine racemase and D-amino acid oxidase, B: alanine racemase and L-alanine dehydrogenase) utilizing a new thermostable enzyme, alanine racemase. Conversion rates from D,L-[3- 11 C]alanine to [3- 11 C]pyruvic acid were almost 100% in both methods. Similar results were obtained with immobilized enzymes packed in a single column. Furthermore, the same column could be used repeatedly without a remarkable decrease of the [3- 11 C]pyruvic acid yield. Various matrices were tested for the immobilizing enzyme, and Aminopropyl-CPG was concluded to be the most suitable since the loss of the enzyme activity was the least in the studied matrices

  9. Pyruvate carboxylation enables growth of SDH-deficient cells by supporting aspartate biosynthesis.

    Science.gov (United States)

    Cardaci, Simone; Zheng, Liang; MacKay, Gillian; van den Broek, Niels J F; MacKenzie, Elaine D; Nixon, Colin; Stevenson, David; Tumanov, Sergey; Bulusu, Vinay; Kamphorst, Jurre J; Vazquez, Alexei; Fleming, Stewart; Schiavi, Francesca; Kalna, Gabriela; Blyth, Karen; Strathdee, Douglas; Gottlieb, Eyal

    2015-10-01

    Succinate dehydrogenase (SDH) is a heterotetrameric nuclear-encoded complex responsible for the oxidation of succinate to fumarate in the tricarboxylic acid cycle. Loss-of-function mutations in any of the SDH genes are associated with cancer formation. However, the impact of SDH loss on cell metabolism and the mechanisms enabling growth of SDH-defective cells are largely unknown. Here, we generated Sdhb-ablated kidney mouse cells and used comparative metabolomics and stable-isotope-labelling approaches to identify nutritional requirements and metabolic adaptations to SDH loss. We found that lack of SDH activity commits cells to consume extracellular pyruvate, which sustains Warburg-like bioenergetic features. We further demonstrated that pyruvate carboxylation diverts glucose-derived carbons into aspartate biosynthesis, thus sustaining cell growth. By identifying pyruvate carboxylase as essential for the proliferation and tumorigenic capacity of SDH-deficient cells, this study revealed a metabolic vulnerability for potential future treatment of SDH-associated malignancies.

  10. Inactivation of pyruvate dehydrogenase kinase 2 by mitochondrial reactive oxygen species.

    Science.gov (United States)

    Hurd, Thomas R; Collins, Yvonne; Abakumova, Irina; Chouchani, Edward T; Baranowski, Bartlomiej; Fearnley, Ian M; Prime, Tracy A; Murphy, Michael P; James, Andrew M

    2012-10-12

    Reactive oxygen species are byproducts of mitochondrial respiration and thus potential regulators of mitochondrial function. Pyruvate dehydrogenase kinase 2 (PDHK2) inhibits the pyruvate dehydrogenase complex, thereby regulating entry of carbohydrates into the tricarboxylic acid (TCA) cycle. Here we show that PDHK2 activity is inhibited by low levels of hydrogen peroxide (H(2)O(2)) generated by the respiratory chain. This occurs via reversible oxidation of cysteine residues 45 and 392 on PDHK2 and results in increased pyruvate dehydrogenase complex activity. H(2)O(2) derives from superoxide (O(2)(.)), and we show that conditions that inhibit PDHK2 also inactivate the TCA cycle enzyme, aconitase. These findings suggest that under conditions of high mitochondrial O(2)(.) production, such as may occur under nutrient excess and low ATP demand, the increase in O(2)() and H(2)O(2) may provide feedback signals to modulate mitochondrial metabolism.

  11. Investigating tumor perfusion and metabolism using multiple hyperpolarized 13C compounds: HP001, pyruvate and urea

    DEFF Research Database (Denmark)

    von Morze, Cornelius; Larson, Peder E.Z.; Hu, Simon

    2012-01-01

    by spectroscopic imaging of hyperpolarized [1-13C]pyruvate would be of great value in exploring the relationship between perfusion and metabolism in cancer. In preclinical normal murine and cancer model studies, we performed both dynamic multislice imaging of the specialized hyperpolarized perfusion compound HP001......The metabolically inactive hyperpolarized agents HP001 (bis-1,1-(hydroxymethyl)-[1-13C]cyclopropane-d8) and urea enable a new type of perfusion magnetic resonance imaging based on a direct signal source that is background-free. The addition of perfusion information to metabolic information obtained...... of separate dynamic HP001 imaging and copolarized pyruvate/urea imaging were compared. A strong and significant correlation (R=0.73, P=.02) detected between the urea and HP001 data confirmed the value of copolarizing urea with pyruvate for simultaneous assessment of perfusion and metabolism....

  12. Identification of a polysaccharide produced by the pyruvate overproducer Candida glabrata CCTCC M202019.

    Science.gov (United States)

    Luo, Zhengshan; Liu, Song; Du, Guocheng; Zhou, Jingwen; Chen, Jian

    2017-06-01

    Candida glabrata has great potential for the accumulation of pyruvate as a preferred strain in pyruvate production by fermentation. However, its substrate conversion rate is relatively low. In this study, a novel polysaccharide containing α-1,4-glucosidic bonds was observed accidentally in screening a high-titer pyruvate strain by atmospheric and room temperature plasma mutagenesis of C. glabrata. Chemical analysis of the partially purified polysaccharide S 4-C10 showed the main components were 1.2% (w/w) protein and 94.2% (w/w) total sugar. Fourier transform infrared and molecular mass distribution analysis indicated that the main component (PSG-2) of S 4-C10 was a small molecular homogeneous protein-bound polysaccharide. Monosaccharide analysis of PSG-2 showed it consisted of glucose, mannose, and fructose. By optimizing the vitamin mix content, 77.6 g L -1 S 4-C10 polysaccharide could be obtained after 72 h fermentation at 30 °C in 500-mL flasks. RT-qPCR analysis showed that transcriptional level of some key genes related to polysaccharide biosynthesis was upregulated compared to that of wild-type strain. By knocking out two most significantly upregulated genes, CAGL0H02695g and CAGL0K10626g, in the wild-type strain, the pyruvate consumption rate was significantly reduced in late pyruvate fermentation phase, while the titer of polysaccharides was reduced by 18.0%. Besides the potential applications of the novel identified polysaccharide, this study provided clues for increasing the conversion ratio of glucose to pyruvate in C. glabrata by further decreasing the accumulation of polysaccharides.

  13. Increased expression of pyruvate carboxylase and biotin protein ligase increases lysine production in a biotin prototrophic Corynebacterium glutamicum strain

    DEFF Research Database (Denmark)

    Wang, Zhihao; Moslehi-Jenabian, Soloomeh; Solem, Christian

    2015-01-01

    pimeloyl-Acyl Carrier Protein [ACP]) formation. Pyruvate carboxylase (pycA), a biotin-dependent enzyme needed for lysine biosynthesis and biotin ligase (birA), which is responsible for attaching biotin to pyruvate carboxylase, were overexpressed by replacing the native promoters with the strong superoxide...

  14. Chronic pyruvate supplementation increases exploratory activity and brain energy reserves in young and middle-aged mice

    Directory of Open Access Journals (Sweden)

    Hennariikka eKoivisto

    2016-03-01

    Full Text Available Numerous studies have reported neuroprotective effects of pyruvate when given in systemic injections. Impaired glucose uptake and metabolism are found in Alzheimer's disease (AD and in AD mouse models. We tested whether dietary pyruvate supplementation is able to provide added energy supply to brain and thereby attenuate aging- or AD-related cognitive impairment. Mice received ~ 800 mg/kg/day Na-pyruvate in their chow for 2- 6 months. In middle-aged wild-type mice and in 6.5-month-old APP/PS1 mice, pyruvate facilitated spatial learning and increased exploration of a novel odor. However, in passive avoidance task for fear memory, the treatment group was clearly impaired. Independent of age, long-term pyruvate increased explorative behavior, which likely explains the paradoxical impairment in passive avoidance. We also assessed pyruvate effects on body weight, muscle force and endurance, and found no effects. Metabolic post-mortem assays revealed increased energy compounds in nuclear magnetic resonance spectroscopy as well as increased brain glycogen storages in the pyruvate group. Pyruvate supplementation may counteract aging-related behavioral impairment but its beneficial effect seems related to increased explorative activity rather than direct memory enhancement.

  15. Functional and structural characterization of a synthetic peptide representing the N-terminal domain of prokaryotic pyruvate dehydrogenase

    NARCIS (Netherlands)

    Hengeveld, A.F.; Mierlo, van C.P.M.; Hooven, van den H.W.; Visser, A.J.W.G.; Kok, de A.

    2002-01-01

    A synthetic peptide (Nterm-E1p) is used to characterize the structure and function of the N-terminal region (amino acid residues 4-45) of the pyruvate dehydrogenase component (E1p) from the pyruvate dehydrogenase multienzyme complex (PDHC) from Azotobacter vinelandii. Activity and binding studies

  16. The disappearance of pyruvic decarboxylase and [alpha]-ketoglutaric decarboxylase from pigeon muscles on thiamine-deficient diets

    NARCIS (Netherlands)

    Montfoort, C.H.

    1955-01-01

    In homogenates of breast muscle and heart muscle acetoin and succinic semialdehyde are final products of the anaerobic metabolism of pyruvate and α-ketoglutarate respectively. Therefore the pyruvic and α-ketoglutaric decarboxylase activities of these muscles could be measured by determining the

  17. Effet de Panicum maximum sur la productivité des femelles primipares durant le cycle de reproduction chez le cobaye (Cavia porcellus L.

    Directory of Open Access Journals (Sweden)

    Danho, M.

    2012-01-01

    Full Text Available Effect of Panicum maximum on Productivity of Primiparous Females during Reproduction Cycle in Guinea Pigs (Cavia porcellus L.. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L. are mainly fed with Panicum maximum. To assess the effect of the latter during pregnancy and lactation (RC of these animals, primiparous dams were fed ad libitum, Panicum maximum alone during the RC (MOD1 or associated with pellets for rabbits during lactation (MOD2, or associated with pellets for rabbits during the last part of the pregnancy period and the lactation (MOD3, or associated with pellets for rabbits during the entire RC (MOD4. The number of corpora lutea per female was 1.3 ± 0.5 and 2.0 ± 0.0 respectively for MOD1 and MOD4. No pre-embryonic mortality was recorded. The mean weight of the young guinea pigs of MOD1 (54.7 ± 10. g was only 55% of that of MOD4 (98.6 ± 13.6 g. At weaning, the average weight gain of young guinea pigs of MOD1 (40.5 ± 22.2 g represented a third of those obtained with other diets that did not significantly differ. At the end of RC, the weight gain of dams was 17 ± 13.3% for MOD1 compared to 50% for MOD2, MOD3 and MOD4. Feeding Panicum maximum alone induces chronic malnutrition which in turn is responsible of the low ovulation rate and reduced growth in guinea pig breeding.

  18. Dissociative electron attachment and anion-induced dimerization in pyruvic acid

    Czech Academy of Sciences Publication Activity Database

    Zawadzki, Mateusz; Ranković, Miloš; Kočišek, Jaroslav; Fedor, Juraj

    2018-01-01

    Roč. 20, č. 10 (2018), s. 6838-6844 ISSN 1463-9076 R&D Projects: GA ČR GA17-04844S; GA ČR GJ16-10995Y Institutional support: RVO:61388955 Keywords : pyruvic acid * electron attachment * dimerization Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.123, year: 2016

  19. Cerebral glutamine concentration and lactate-pyruvate ratio in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, P.N.; Hauerberg, J.; Frederiksen, Hans-Jørgen

    2008-01-01

    AIM: Hyperammonemia causes brain edema and high intracranial pressure (ICP) in acute liver failure (ALF) by accumulation of glutamine in brain. Since a high-level glutamine may compromise mitochondrial function, the aim of this study was to determine if the lactate-pyruvate ratio is associated...... with a rise in the glutamine concentration and ICP. PATIENTS AND METHODS: In 13 patients with ALF (8F/5M; median age 46 (range 18-66) years) the cerebral extracellular concentrations of glutamine, lactate, and pyruvate were measured by in vivo brain microdialysis together with ICP and cerebral perfusion...... pressure (CPP). RESULTS: The cerebral glutamine concentration was 4,396 (1,011-9,712) microM, lactate 2.15 (1.1-4.45) mM, and pyruvate 101 (43-255) microM. The lactate-pyruvate ratio was 21 (16-40), ICP 20 (2-28) mmHg, and CPP 72 (56-115) mmHg. Cerebral glutamine concentration correlated with the lactate...

  20. Pyruvate Oxidase Influences the Sugar Utilization Pattern and Capsule Production in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Carvalho, Sandra M.; Farshchi Andisi, Vahid; Gradstedt, Henrik; Neef, Jolanda; Kuipers, Oscar P.; Neves, Ana R.; Bijlsma, Jetta J. E.

    2013-01-01

    Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence,

  1. Metabolic imaging of patients with prostate cancer using hyperpolarized [1-¹³C]pyruvate

    DEFF Research Database (Denmark)

    Nelson, Sarah J; Kurhanewicz, John; Vigneron, Daniel B

    2013-01-01

    This first-in-man imaging study evaluated the safety and feasibility of hyperpolarized [1-¹³C]pyruvate as an agent for noninvasively characterizing alterations in tumor metabolism for patients with prostate cancer. Imaging living systems with hyperpolarized agents can result in more than 10,000-f...

  2. Exercise-induced pyruvate dehydrogenase activation is not affected by 7 days of bed rest

    DEFF Research Database (Denmark)

    Kiilerich, Kristian; Jørgensen, Stine Ringholm; Biensø, Rasmus Sjørup

    2011-01-01

    To test the hypothesis that physical inactivity impairs the exercise-induced modulation of pyruvate dehydrogenase (PDH), 6 healthy normally physically active male subjects completed 7 days of bed rest. Before and immediately after the bed rest, the subjects completed an OGTT and a one-legged knee...

  3. Studies to enhance the hyperpolarization level in PHIP-SAH-produced C13-pyruvate

    Science.gov (United States)

    Cavallari, Eleonora; Carrera, Carla; Aime, Silvio; Reineri, Francesca

    2018-04-01

    The use of [1-13C]pyruvate, hyperpolarized by dissolution-Dynamic Nuclear Polarization (d-DNP), in in vivo metabolic studies has developed quickly, thanks to the imaging probe's diagnostic relevance. Nevertheless, the cost of a d-DNP polarizer is quite high and the speed of hyperpolarization process is relatively slow, meaning that its use is limited to few research laboratories. ParaHydrogen Induced Polarization Side Arm Hydrogenation (PHIP-SAH) (Reineri et al., 2015) is a cost effective and easy-to-handle method that produces 13C-MR hyperpolarization in [1-13C]pyruvate and other metabolites. This work aims to identify the main determinants of the hyperpolarization levels observed in C13-pyruvate using this method. By dissecting the various steps of the PHIP-SAH procedure, it has been possible to assess the role of several experimental parameters whose optimization must be pursued if this method is to be made suitable for future translational steps. The search for possible solutions has led to improvements in the polarization of sodium [1-13C]pyruvate from 2% to 5%. Moreover, these results suggest that observed polarization levels could be increased considerably by an automatized procedure which would reduce the time required for the work-up passages that are currently carried out manually. The results reported herein mean that the attainment of polarization levels suitable for the metabolic imaging applications of these hyperpolarized substrates show significant promise.

  4. Multi site Kinetic Modeling of 13C Metabolic MR Using [1-13C]Pyruvate

    International Nuclear Information System (INIS)

    Damian, P.A.G.; Sperl, J.I.; Janich, M.A.; Wiesinger, F.; Schulte, R.F.; Menzel, M.I.; Damian, P.A.G.; Damian, P.A.G.; Haase, A.; Janich, M.A.; Schwaiger, M.; Janich, M.A.; Khegai, O.; Glaser, S.J.

    2014-01-01

    Hyperpolarized 13 C imaging allows real-time in vivo measurements of metabolite levels. Quantification of metabolite conversion between [1- 13 C]pyruvate and downstream metabolites [1- 13 C]alanine, [1- 13 C]lactate, and [ 13 C] bicarbonate can be achieved through kinetic modeling. Since pyruvate interacts dynamically and simultaneously with its downstream metabolites, the purpose of this work is the determination of parameter values through a multi site, dynamic model involving possible biochemical pathways present in MR spectroscopy. Kinetic modeling parameters were determined by fitting the multi site model to time-domain dynamic metabolite data. The results for different pyruvate doses were compared with those of different two-site models to evaluate the hypothesis that for identical data the uncertainty of a model and the signal-to-noise ratio determine the sensitivity in detecting small physiological differences in the target metabolism. In comparison to the two-site exchange models, the multi site model yielded metabolic conversion rates with smaller bias and smaller standard deviation, as demonstrated in simulations with different signal-to-noise ratio. Pyruvate dose effects observed previously were confirmed and quantified through metabolic conversion rate values. Parameter interdependency allowed an accurate quantification and can therefore be useful for monitoring metabolic activity in different tissues

  5. Multisite Kinetic Modeling of 13C Metabolic MR Using [1-13C]Pyruvate

    Directory of Open Access Journals (Sweden)

    Pedro A. Gómez Damián

    2014-01-01

    Full Text Available Hyperpolarized 13C imaging allows real-time in vivo measurements of metabolite levels. Quantification of metabolite conversion between [1-13C]pyruvate and downstream metabolites [1-13C]alanine, [1-13C]lactate, and [13C]bicarbonate can be achieved through kinetic modeling. Since pyruvate interacts dynamically and simultaneously with its downstream metabolites, the purpose of this work is the determination of parameter values through a multisite, dynamic model involving possible biochemical pathways present in MR spectroscopy. Kinetic modeling parameters were determined by fitting the multisite model to time-domain dynamic metabolite data. The results for different pyruvate doses were compared with those of different two-site models to evaluate the hypothesis that for identical data the uncertainty of a model and the signal-to-noise ratio determine the sensitivity in detecting small physiological differences in the target metabolism. In comparison to the two-site exchange models, the multisite model yielded metabolic conversion rates with smaller bias and smaller standard deviation, as demonstrated in simulations with different signal-to-noise ratio. Pyruvate dose effects observed previously were confirmed and quantified through metabolic conversion rate values. Parameter interdependency allowed an accurate quantification and can therefore be useful for monitoring metabolic activity in different tissues.

  6. Pyruvate Kinase Triggers a Metabolic Feedback Loop that Controls Redox Metabolism in Respiring Cells

    NARCIS (Netherlands)

    Grüning, N.M.; Rinnerthaler, M.; Bluemlein, K.; Mulleder, M.; Wamelink, M.M.C.; Lehrach, H.; Jakobs, C.A.J.M.; Breitenbach, M.; Ralser, M.

    2011-01-01

    In proliferating cells, a transition from aerobic to anaerobic metabolism is known as the Warburg effect, whose reversal inhibits cancer cell proliferation. Studying its regulator pyruvate kinase (PYK) in yeast, we discovered that central metabolism is self-adapting to synchronize redox metabolism

  7. Embryonic Lethality of Mitochondrial Pyruvate Carrier 1 Deficient Mouse Can Be Rescued by a Ketogenic Diet

    Science.gov (United States)

    Krznar, Petra; Hörl, Manuel; Ammar, Zeinab; Montessuit, Sylvie; Pierredon, Sandra; Zamboni, Nicola; Martinou, Jean-Claude

    2016-01-01

    Mitochondrial import of pyruvate by the mitochondrial pyruvate carrier (MPC) is a central step which links cytosolic and mitochondrial intermediary metabolism. To investigate the role of the MPC in mammalian physiology and development, we generated a mouse strain with complete loss of MPC1 expression. This resulted in embryonic lethality at around E13.5. Mouse embryonic fibroblasts (MEFs) derived from mutant mice displayed defective pyruvate-driven respiration as well as perturbed metabolic profiles, and both defects could be restored by reexpression of MPC1. Labeling experiments using 13C-labeled glucose and glutamine demonstrated that MPC deficiency causes increased glutaminolysis and reduced contribution of glucose-derived pyruvate to the TCA cycle. Morphological defects were observed in mutant embryonic brains, together with major alterations of their metabolome including lactic acidosis, diminished TCA cycle intermediates, energy deficit and a perturbed balance of neurotransmitters. Strikingly, these changes were reversed when the pregnant dams were fed a ketogenic diet, which provides acetyl-CoA directly to the TCA cycle and bypasses the need for a functional MPC. This allowed the normal gestation and development of MPC deficient pups, even though they all died within a few minutes post-delivery. This study establishes the MPC as a key player in regulating the metabolic state necessary for embryonic development, neurotransmitter balance and post-natal survival. PMID:27176894

  8. Lactate and Lactate: Pyruvate Ratio in the Diagnosis and Outcomes of Pediatric Acute Liver Failure.

    Science.gov (United States)

    Feldman, Amy G; Sokol, Ronald J; Hardison, Regina M; Alonso, Estella M; Squires, Robert H; Narkewicz, Michael R

    2017-03-01

    To assess the accuracy of blood lactate and lactate: pyruvate molar ratio (L:P) as a screen for mitochondrial, respiratory chain, or fatty acid oxidation disorders in children with pediatric acute liver failure (PALF); to determine whether serum lactate ≥ 2.5 mmol/L or L:P  ≥ 25 correlated with biochemical variables of clinical severity; and to determine whether lactate or L:P is associated with clinical outcome at 21 days. Retrospective review of demographic, clinical, laboratory, and outcome data for PALF study group participants who had lactate and pyruvate levels collected on the same day. Of 986 participants, 110 had lactate and pyruvate levels collected on the same day. Of the 110, the etiology of PALF was a mitochondrial disorder in 8 (7%), indeterminate in 65 (59%), and an alternative diagnosis in 37 (34%). Lactate, pyruvate, and L:P were similar among the 3 etiologic groups. There was no significant association between the initial lactate or L:P and biochemical variables of clinical severity or clinical outcome at 21 days. A serum lactate ≥ 2.5 mmol/L and/or elevated L:P was common in all causes of PALF, not limited to those with a mitochondrial etiology, and did not predict 21-day clinical outcome. ClinicalTrials.gov: NCT00986648. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Assessment of Hepatic Mitochondrial Oxidation and Pyruvate Cycling in NAFLD by (13)C Magnetic Resonance Spectroscopy

    DEFF Research Database (Denmark)

    Petersen, Kitt Mia Falck; Befroy, Douglas E; Dufour, Sylvie

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and there is great interest in understanding the potential role of alterations in mitochondrial metabolism in its pathogenesis. To address this question, we assessed rates of hepatic mitochondrial oxidation in sub...... mitochondrial oxidation and pyruvate cycling are not altered in NAFLD and do not account for the hepatic fat accumulation....

  10. Effect of Glycine, Pyruvate, and Resveratrol on the Regeneration Process of Postischemic Intestinal Mucosa

    Directory of Open Access Journals (Sweden)

    Lisa Brencher

    2017-01-01

    Full Text Available Background. Intestinal ischemia is often caused by a malperfusion of the upper mesenteric artery. Since the intestinal mucosa is one of the most rapidly proliferating organs in human body, this tissue can partly regenerate itself after the onset of ischemia and reperfusion (I/R. Therefore, we investigated whether glycine, sodium pyruvate, and resveratrol can either support or potentially harm regeneration when applied therapeutically after reperfusion injury. Methods. I/R of the small intestine was initiated by occluding and reopening the upper mesenteric artery in rats. After 60 min of ischemia and 300 min of reperfusion, glycine, sodium pyruvate, or resveratrol was administered intravenously. Small intestine regeneration was analyzed regarding tissue damage, activity of saccharase, and Ki-67 positive cells. Additionally, systemic parameters and metabolic ones were obtained at selected periods. Results. Resveratrol failed in improving the outcome after I/R, while glycine showed a partial beneficial effect. Sodium pyruvate ameliorated metabolic acidosis, diminished histopathologic tissue injury, and increased cell proliferation in the small intestine. Conclusion. While glycine could improve in part regeneration but not proliferation, sodium pyruvate seems to be a possible therapeutic agent to facilitate proliferation and to support mucosal regeneration after I/R injury to the small intestine.

  11. Study of a cleaner extraction of pyruvic acid from fermentation broth ...

    African Journals Online (AJOL)

    A new cleaner technology for extracting pyruvic acid (PA) from fermentative broth was explored. This process involves recycling waste residue combined with small amount of dispersant added to extract PA. Limited amount of dispersant in the process of rectification under vacuum (1.5 kPa) was found to inhibit the ...

  12. Cerebral glutamine concentration and lactate-pyruvate ratio in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, P.N.; Hauerberg, J.; Frederiksen, Hans-Jørgen

    2008-01-01

    AIM: Hyperammonemia causes brain edema and high intracranial pressure (ICP) in acute liver failure (ALF) by accumulation of glutamine in brain. Since a high-level glutamine may compromise mitochondrial function, the aim of this study was to determine if the lactate-pyruvate ratio is associated...

  13. Serine is a natural ligand and allosteric activator of pyruvate kinase M2

    NARCIS (Netherlands)

    Chaneton, Barbara; Hillmann, Petra; Zheng, Liang; Martin, Agnes C. L.; Maddocks, Oliver D. K.; Chokkathukalam, Achuthanunni; Coyle, Joseph E.; Jankevics, Andris; Holding, Finn P.; Vousden, Karen H.; Frezza, Christian; O'Reilly, Marc; Gottlieb, Eyal

    2012-01-01

    Cancer cells exhibit several unique metabolic phenotypes that are critical for cell growth and proliferation(1). Specifically, they overexpress the M2 isoform of the tightly regulated enzyme pyruvate kinase (PKM2), which controls glycolytic flux, and are highly dependent on de novo biosynthesis of

  14. Specific Arabidopsis thaliana malic enzyme isoforms can provide anaplerotic pyruvate carboxylation function in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Badia, Mariana Beatriz; Mans, R.; Lis, A.V.; Tronconi, Marcos Ariel; Arias, Cintia Lucía; Maurino, Verónica Graciela; Andreo, Carlos Santiago; Drincovich, María Fabiana; van Maris, A.J.A.; Gerrard Wheeler, Mariel Claudia

    2017-01-01

    NAD(P)-malic enzyme (NAD(P)-ME) catalyzes the reversible oxidative decarboxylation of malate to pyruvate, CO2, and NAD(P)H and is present as a multigene family in Arabidopsis thaliana. The carboxylation reaction catalyzed by purified recombinant Arabidopsis NADP-ME proteins is faster

  15. M-Type Pyruvate Kinase Isoforms and Lactate Dehydrogenase A in the Mammalian Retina: Metabolic Implications.

    Science.gov (United States)

    Casson, Robert J; Wood, John P M; Han, Guoge; Kittipassorn, Thaksaon; Peet, Daniel J; Chidlow, Glyn

    2016-01-01

    Like cancer cells, photoreceptor cells produce lactate aerobically, requiring lactate dehydrogenase A (LDH-A). Cancer cells also use glycolytic intermediates for biosynthesis. The molecular switch controlling glycolytic flow is thought to be an isoenzyme of pyruvate kinase (PKM2). Here, we determined the expression and localization of PKM2 and LDH-A in mammalian retina and make comparisons with the brain. Single- and double-labeling immunohistochemistry for PKM2, pyruvate kinase M1 (PKM1), and LDH-A were performed using retinal sections from C57BL/6 mice, Sprague-Dawley rats, rabbits, marmosets, and humans. Pyruvate kinase M1 and PKM2 mRNA and protein expression levels were quantified in rodent retina and brain by using qPCR and immunoblotting. The quaternary forms of PKM2 in rat retina were also determined. Pyruvate kinase M2 was present in some glial cells and rod and cone photoreceptors in the retina of all species but was exclusively localized to glia in the brain. Pyruvate kinase M1 was confined to neurons in the retina and brain. Lactate dehydrogenase A was principally found in photoreceptors and inner portion of the avascular rabbit retina. Western blotting and qPCR confirmed high levels of PKM2 and LDH-A in the retina. There was a 6- to 9-fold greater expression of PKM2 mRNA in the rodent retina than in the brain. Both the dimeric (inactive, biosynthesis-driving form) and the active tetrameric (glycolytic-driving) forms of PKM2 were present in retina but not in brain. Mammalian photoreceptors contain dimeric and tetrameric PKM2 and LDH-A. This is consistent with the ability to switch between energy production and biosynthesis like a proliferating tissue, possibly due to demands of opsin synthesis.

  16. 13C NMR study of effects of fasting and diabetes on the metabolism of pyruvate in the tricarboxylic acid cycle and of the utilization of pyruvate and ethanol in lipogenesis in perfused rat liver

    International Nuclear Information System (INIS)

    Cohen, S.M.

    1987-01-01

    13 C NMR has been used to study the competition of pyruvate dehydrogenase with pyruvate carboxylase for entry of pyruvate into the tricarboxylic acid (TCA) cycle in perfused liver from streptozotocin-diabetic and normal donor rats. The relative proportion of pyruvate entering the TCA cycle by these two routes was estimated from the 13 C enrichments at the individual carbons of glutamate when [3- 13 C]alanine was the only exogenous substrate present. In this way, the proportion of pyruvate entering by the pyruvate dehydrogenase route relative to the pyruvate carboxylase route was determined to be 1:1.2 +/- 0.1 in liver from fed controls, 1:7.7 +/- 2 in liver from 24-fasted controls, and 1:2.6 +/- 0.3 in diabetic liver. Pursuant to this observation that conversion of pyruvate to acetyl coenzyme A (acetyl-CoA) was greatest in perfused liver from fed controls, the incorporation of 13 C label into fatty acids was monitored in this liver preparation. With the exception of the repeating methylene carbons, fatty acyl carbons labeled by [1- 13 C]acetyl-CoA (from [2- 13 C]pyruvate) gave rise to resonances distinguishable on the basis of chemical shift from those observed when label was introduced by [3- 13 C]alanine plus [2- 13 C]ethanol, which are converted to [2- 13 C]acetyl-CoA. Thus, measurement of 13 C enrichment at several specific sites in the fatty acyl chains in time-resolved spectra of perfused liver offers a novel way of monitoring the kinetics of the biosynthesis of fatty acids. In addition to obtaining the rate of lipogenesis, it was possible to distinguish the contributions of chain elongation from those of the de novo synthesis pathway and to estimate the average chain length of the 13 C-labeled fatty acids produced

  17. Inhibition of Mitochondrial Pyruvate Transport by Zaprinast Causes Massive Accumulation of Aspartate at the Expense of Glutamate in the Retina*

    Science.gov (United States)

    Du, Jianhai; Cleghorn, Whitney M.; Contreras, Laura; Lindsay, Ken; Rountree, Austin M.; Chertov, Andrei O.; Turner, Sally J.; Sahaboglu, Ayse; Linton, Jonathan; Sadilek, Martin; Satrústegui, Jorgina; Sweet, Ian R.; Paquet-Durand, François; Hurley, James B.

    2013-01-01

    Transport of pyruvate into mitochondria by the mitochondrial pyruvate carrier is crucial for complete oxidation of glucose and for biosynthesis of amino acids and lipids. Zaprinast is a well known phosphodiesterase inhibitor and lead compound for sildenafil. We found Zaprinast alters the metabolomic profile of mitochondrial intermediates and amino acids in retina and brain. This metabolic effect of Zaprinast does not depend on inhibition of phosphodiesterase activity. By providing 13C-labeled glucose and glutamine as fuels, we found that the metabolic profile of the Zaprinast effect is nearly identical to that of inhibitors of the mitochondrial pyruvate carrier. Both stimulate oxidation of glutamate and massive accumulation of aspartate. Moreover, Zaprinast inhibits pyruvate-driven O2 consumption in brain mitochondria and blocks mitochondrial pyruvate carrier in liver mitochondria. Inactivation of the aspartate glutamate carrier in retina does not attenuate the metabolic effect of Zaprinast. Our results show that Zaprinast is a potent inhibitor of mitochondrial pyruvate carrier activity, and this action causes aspartate to accumulate at the expense of glutamate. Our findings show that Zaprinast is a specific mitochondrial pyruvate carrier (MPC) inhibitor and may help to elucidate the roles of MPC in amino acid metabolism and hypoglycemia. PMID:24187136

  18. Inhibition of mitochondrial pyruvate transport by zaprinast causes massive accumulation of aspartate at the expense of glutamate in the retina.

    Science.gov (United States)

    Du, Jianhai; Cleghorn, Whitney M; Contreras, Laura; Lindsay, Ken; Rountree, Austin M; Chertov, Andrei O; Turner, Sally J; Sahaboglu, Ayse; Linton, Jonathan; Sadilek, Martin; Satrústegui, Jorgina; Sweet, Ian R; Paquet-Durand, François; Hurley, James B

    2013-12-13

    Transport of pyruvate into mitochondria by the mitochondrial pyruvate carrier is crucial for complete oxidation of glucose and for biosynthesis of amino acids and lipids. Zaprinast is a well known phosphodiesterase inhibitor and lead compound for sildenafil. We found Zaprinast alters the metabolomic profile of mitochondrial intermediates and amino acids in retina and brain. This metabolic effect of Zaprinast does not depend on inhibition of phosphodiesterase activity. By providing (13)C-labeled glucose and glutamine as fuels, we found that the metabolic profile of the Zaprinast effect is nearly identical to that of inhibitors of the mitochondrial pyruvate carrier. Both stimulate oxidation of glutamate and massive accumulation of aspartate. Moreover, Zaprinast inhibits pyruvate-driven O2 consumption in brain mitochondria and blocks mitochondrial pyruvate carrier in liver mitochondria. Inactivation of the aspartate glutamate carrier in retina does not attenuate the metabolic effect of Zaprinast. Our results show that Zaprinast is a potent inhibitor of mitochondrial pyruvate carrier activity, and this action causes aspartate to accumulate at the expense of glutamate. Our findings show that Zaprinast is a specific mitochondrial pyruvate carrier (MPC) inhibitor and may help to elucidate the roles of MPC in amino acid metabolism and hypoglycemia.

  19. Interactions between Pyruvate and Lactate Metabolism in Propionibacterium freudenreichii subsp. shermanii: In Vivo 13C Nuclear Magnetic Resonance Studies

    Science.gov (United States)

    Deborde, Catherine; Boyaval, Patrick

    2000-01-01

    In vivo 13C nuclear magnetic resonance spectroscopy was used to elucidate the pathways and the regulation of pyruvate metabolism and pyruvate-lactate cometabolism noninvasively in living-cell suspensions of Propionibacterium freudenreichii subsp. shermanii. The most important result of this work concerns the modification of fluxes of pyruvate metabolism induced by the presence of lactate. Pyruvate was temporarily converted to lactate and alanine; the flux to acetate synthesis was maintained, but the flux to propionate synthesis was increased; and the reverse flux of the first part of the Wood-Werkman cycle, up to acetate synthesis, was decreased. Pyruvate was consumed at apparent initial rates of 148 and 90 μmol · min−1 · g−1 (cell dry weight) when it was the sole substrate or cometabolized with lactate, respectively. Lactate was consumed at an apparent initial rate of 157 μmol · min−1 · g−1 when it was cometabolized with pyruvate. P. shermanii used several pathways, namely, the Wood-Werkman cycle, synthesis of acetate and CO2, succinate synthesis, gluconeogenesis, the tricarboxylic acid cycle, and alanine synthesis, to manage its pyruvate pool sharply. In both types of experiments, acetate synthesis and the Wood-Werkman cycle were the metabolic pathways used most. PMID:10788375

  20. Interactions between pyruvate and lactate metabolism in Propionibacterium freudenreichii subsp. shermanii: in vivo (13)C nuclear magnetic resonance studies.

    Science.gov (United States)

    Deborde, C; Boyaval, P

    2000-05-01

    In vivo (13)C nuclear magnetic resonance spectroscopy was used to elucidate the pathways and the regulation of pyruvate metabolism and pyruvate-lactate cometabolism noninvasively in living-cell suspensions of Propionibacterium freudenreichii subsp. shermanii. The most important result of this work concerns the modification of fluxes of pyruvate metabolism induced by the presence of lactate. Pyruvate was temporarily converted to lactate and alanine; the flux to acetate synthesis was maintained, but the flux to propionate synthesis was increased; and the reverse flux of the first part of the Wood-Werkman cycle, up to acetate synthesis, was decreased. Pyruvate was consumed at apparent initial rates of 148 and 90 micromol. min(-1). g(-1) (cell dry weight) when it was the sole substrate or cometabolized with lactate, respectively. Lactate was consumed at an apparent initial rate of 157 micromol. min(-1). g(-1) when it was cometabolized with pyruvate. P. shermanii used several pathways, namely, the Wood-Werkman cycle, synthesis of acetate and CO(2), succinate synthesis, gluconeogenesis, the tricarboxylic acid cycle, and alanine synthesis, to manage its pyruvate pool sharply. In both types of experiments, acetate synthesis and the Wood-Werkman cycle were the metabolic pathways used most.

  1. Pyruvate transport in isolated cardiac mitochondria from two species of amphibian exhibiting dissimilar aerobic scope: Bufo marinus and Rana catesbeiana.

    Science.gov (United States)

    Duerr, Jeffrey M; Tucker, Kristina

    2007-08-01

    Cardiac mitochondria were isolated from Bufo marinus and Rana catesbeiana, two species of amphibian whose cardiovascular systems are adapted to either predominantly aerobic or glycolytic modes of locomotion. Mitochondrial oxidative capacity was compared using VO2 max and respiratory control ratios in the presence of a variety of substrates including pyruvate, lactate, oxaloacetate, beta-hydroxybutyrate, and octanoyl-carnitine. B. marinus cardiac mitochondria exhibited VO2 max values twice that of R. catesbeiana cardiac mitochondria when oxidizing carbohydrate substrates. Pyruvate transport was measured via a radiolabeled-tracer assay in isolated B. marinus and R. catesbeiana cardiac mitochondria. Time-course experiments described both alpha-cyano-4-hydroxycinnamate-sensitive (MCT-like) and phenylsuccinate-sensitive pyruvate uptake mechanisms in both species. Pyruvate uptake by the MCT-like transporter was enhanced in the presence of a pH gradient, whereas the phenylsuccinate-sensitive transporter was inhibited. Notably, anuran cardiac mitochondria exhibited activities of lactate dehydrogenase and pyruvate carboxylase. The presence of both transporters on the inner mitochondrial membrane affords the net uptake of monocarboxylates including pyruvate, beta-hydroxybutyrate, and lactate; the latter potentially indicating the presence of a lactate/pyruvate shuttle allowing oxidation of extramitochondrial NADH. Intramitochondrial lactate dehydrogenase and pyruvate carboxylase enables lactate to be oxidized to pyruvate or converted to anaplerotic oxaloacetate. Kinetics of the MCT-like transporter differed significantly between the two species, suggesting differences in aerobic scope may be in part attributable to differences in mitochondrial carbohydrate utilization. (c) 2007 Wiley-Liss, Inc.

  2. Pyruvate diminishes the cytotoxic activity of ascorbic acid in several tumor cell lines in vitro.

    Science.gov (United States)

    Rodemeister, Sandra; Hill, Katharina

    2017-11-25

    The anticancer potential of ascorbic acid (AA) has been controversially discussed for decades. Although the cytotoxic effect of pharmacologic concentrations of ascorbic acid has already been successfully demonstrated in numerous studies in vitro, it could not be verified to the same extent in vivo. We propose that the ubiquitous metabolite pyruvate diminishes the effect of AA by reacting with its presumable cytotoxic mediator hydrogen peroxide (H 2 O 2 ). MTT assays confirm that co-incubation with 1.4 mM pyruvate abolishes the cytotoxic effect of pharmacologic concentrations of AA in all cancer cell lines tested (human melanoma (WM451-Lu), breast (MCF-7) and hypopharyngeal cancer cells (FaDu)). We further investigated whether pyruvate diminishes the anticancer effect of AA by interfering with the generation of H 2 O 2 . Therefore, we analyzed the concentration of AFR, a proposed intermediate in the AA-dependent formation of H 2 O 2, by electron paramagnetic resonance spectroscopy, during incubation with AA and pyruvate in WM451-Lu cells as a model system. In addition, we measured H 2 O 2 concentration by indirect detection with Clark-type oxygen electrode. AFR concentration was not significantly influenced by pyruvate, whereas H 2 O 2 concentration was significantly reduced. In parallel, pyruvate concentrations of the stimulation medium declined with increasing AA and consequently H 2 O 2 concentrations. In summary, pyruvate diminishes the cytotoxic activity of ascorbic acid in vitro. The AFR concentration measured remains unaffected by pyruvate whereas the H 2 O 2 concentration is reduced; confirming that pyruvate directly reacts with AA-induced H 2 O 2 , without influencing its formation. However, further experiments are needed to elucidate the complex mechanisms being responsible for the reduced efficacy of AA in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Regulation of pyruvate oxidation in blowfly flight muscle mitochondria: requirement for ADP.

    Science.gov (United States)

    Bulos, B A; Thomas, B J; Shukla, S P; Sacktor, B

    1984-11-01

    Blowfly (Phormia regina) flight muscle mitochondria oxidized pyruvate ( + proline) in the presence of either ADP (coupled respiration) or carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP-uncoupled respiration). There was an absolute requirement for ADP (Km = 8.0 microM) when pyruvate oxidation was stimulated by FCCP in the presence of oligomycin. This requirement for ADP was limited to the oxidation of pyruvate; uncoupled alpha-glycerolphosphate oxidation proceeded maximally even in the absence of added ADP. Atractylate inhibited uncoupled pyruvate oxidation whether added before (greater than 99%) or after (95%) initiation of respiration with FCCP. In the presence of FCCP, oligomycin, and limiting concentrations of ADP (less than 110 microM), there was a shutoff in the uptake of oxygen. This inhibition of respiration was completely reversed by the addition of more ADP. Plots of net oxygen uptake as a function of the limiting ADP concentration were linear; the observed ADP/O ratio was 0.22 +/- 0.025. An ADP/O ratio of 0.2 was predicted if phosphorylation occurred only at the succinyl-CoA synthetase step of the tricarboxylate cycle. Experiments performed in the presence of limiting concentrations of ADP, and designed to monitor changes in the mitochondrial content of ADP and ATP, demonstrated that the shutoff in oxygen uptake was not due to the presence of a high intramitochondrial concentration of ATP. Indeed, ATP, added to the medium prior to the addition of FCCP, inhibited uncoupled pyruvate oxidation; the apparent KI was 0.8 mM. These results are consistent with the hypothesis that it is the intramitochondrial ATP/ADP ratio that is one of the controlling factors in determining the rate of flux through the tricarboxylate cycle. Changes in the mitochondrial content of citrate, isocitrate, alpha-ketoglutarate, and malate during uncoupled pyruvate oxidation in the presence of a limiting concentration of ADP were consistent with the hypothesis that the

  4. Ethyl Pyruvate Prevents Methyglyoxal-Induced Retinal Vascular Injury in Rats

    Directory of Open Access Journals (Sweden)

    Junghyun Kim

    2013-01-01

    Full Text Available Pyruvate is an endogenous antioxidant substance. The aim of this study was to investigate the protective effects of ethyl pyruvate (EP on retinal vascular injury in diabetic retinopathy. To investigate the protective effect of EP on vascular cell apoptosis and blood-retinal barrier (BRB breakage, we have used intravitreally methylglyoxal-(MGO- injected rat eyes. Apoptosis of the retinal vascular cell that was stimulated by the intravitreal injection of MGO was evidently attenuated by the EP treatment. EP exerts inhibitory effect on MGO-induced vascular cell apoptosis by blocking oxidative injury. In addition, EP treatment prevented MGO-induced BRB breakage and the degradation of occludin, an important tight junction protein. These observations suggest that EP acts through an antioxidant mechanism to protect against oxidative stress-induced apoptosis in retinal vessels.

  5. Anaerobic survival of Pseudomonas aeruginosa by pyruvate fermentation requires an Usp-type stress protein

    DEFF Research Database (Denmark)

    Schreiber, K; Boes, N; Escbach, M

    2006-01-01

    activity was detected in the deeper layers of a P. aeruginosa biofilm using a PPA3309-gfp (green fluorescent protein gene) fusion and confocal laser-scanning microscopy. This is the first description of an Anr-dependent, anaerobically induced, and functional Usp-like protein in bacteria....... the induced synthesis of three enzymes involved in arginine fermentation, ArcA, ArcB, and ArcC, and the outer membrane protein OprL. Moreover, formation of two proteins of unknown function, PA3309 and PA4352, increased by factors of 72- and 22-fold, respectively. Both belong to the group of universal stress...... proteins (Usp). Long-term survival of a PA3309 knockout mutant by pyruvate fermentation was found drastically reduced. The oxygen-sensing regulator Anr controls expression of the PPA3309-lacZ reporter gene fusion after a shift to anaerobic conditions and further pyruvate fermentation. PA3309 expression...

  6. Reconciling diabetes management and the ketogenic diet in a child with pyruvate dehydrogenase deficiency.

    Science.gov (United States)

    Henwood, Maria J; Thornton, Paul S; Preis, Christina M; Chee, Clare; Grimberg, Adda

    2006-05-01

    A 4-year-old girl with pyruvate dehydrogenase deficiency, static encephalopathy, and seizure disorder treated with the ketogenic diet presented in severe diabetic ketoacidosis. Pyruvate dehydrogenase deficiency is a rare genetic defect of mitochondrial energy metabolism that leads to inefficient glucose use and lactic acidosis. The ketogenic diet provides the brain with an alternate fuel source, but its implementation opposes traditional diabetes management. Faced with this therapeutic dilemma, we aimed to maintain ketosis without compromising safety to optimize neurologic function and quality of life. This is the first report, to our knowledge, of a child simultaneously treated with the ketogenic diet and exogenous insulin. A 28-month follow-up revealed excellent glycemic control, improved activity level, significant developmental achievements, and, perhaps most striking, catch-up linear growth from diabetes does not preclude use of the ketogenic diet.

  7. Direct measurement of backflux between oxaloacetate and fumarate following pyruvate carboxylation

    DEFF Research Database (Denmark)

    Brekke, Eva; Walls, Anne Byriel; Nørfeldt, Lasse

    2012-01-01

    Pyruvate carboxylation (PC) is thought to be the major anaplerotic reaction for the tricarboxylic acid cycle and is necessary for de novo synthesis of amino acid neurotransmitters. In the brain, the main enzyme involved is pyruvate carboxylase, which is predominantly located in astrocytes...... for quantification of activity of PC lead to underestimation when backflux is not taken into account and critical errors have been made in the interpretation of results from metabolic studies. This study was conducted to establish the degree of backflux after PC in cerebellar and neocortical astrocytes. Astrocyte...... in both types of astrocytes. The extent of backflux varied between the metabolites, reaffirming that metabolism is highly compartmentalized. By applying our calculations to published data, we demonstrate the existence of backflux in vivo in cat, rat, mouse, and human brain. Thus, backflux should be taken...

  8. Erythrocyte pyruvate kinase deficiency in the Ohio Amish: origin and characterization of the mutant enzyme.

    OpenAIRE

    Muir, W A; Beutler, E; Wasson, C

    1984-01-01

    We have identified eight individuals in an Amish population in Geauga County, Ohio, who have a congenital hemolytic anemia and red cell pyruvate kinase (PK) deficiency. The mutant enzyme is a low Km phosphoenolpyruvate (PEP) variant associated with a slower (77.5% of normal) electrophoretic mobility in starch gel. Because of the high consanguinity in this population, we assume the affected individuals are homozygous for the mutant gene. Genealogical records allow us to trace all eight cases b...

  9. The relationship between intracranial pressure and lactate/pyruvate ratio in patients with subarachnoid haemorrhage.

    Science.gov (United States)

    Cesak, T; Adamkov, J; Habalova, J; Poczos, P; Kanta, M; Bartos, M; Hosszu, T

    2018-01-01

    The aim of this study was to analyse the relationship between intracranial pressure (intracranial pressure monitoring) and lactate pyruvate ratio (cerebral microdialysis) in patients with ruptured intracranial aneurysms. In a group of fifteen patients, intracranial pressure and lactate/pyruvate ratios were measured and logged in hourly intervals. The relationship between these two variables was subsequently analysed in two ways. 1) Intracranial hypertension (ICP > 20 mmHg) in the presence of energy deprivation (L/P ratio > 30) was noted. 2) The dynamics of L/P ratio changes in relation to immediate ICP and CPP values was analysed. Out of a total of 1873 monitored hours we were able to record lactate/pyruvate ratios higher than 30 in 832 hours (44 %). Of those 832 hours during which lactate/pyruvate ratios were higher than 30, ICP was higher than 20 in 193 hours (23 %). Out of 219 hours of monitoring, in which ICP was higher than 20, a simultaneously increased L/P ratio higher than 30 was recorded in 193 hours (88 %). L/P ratio values above 30 were associated with decreased CPP values (p = 0.04), but not with increased ICP values (p = 0.79). Intracranial hypertension coincides with energetic imbalance in approximately one quarter of cases. This points to the shortcomings of the most common form of neuromonitoring in SAH patients - ICP monitoring. This method may not be reliable enough in detecting hypoxic damage, which is the major cause of morbidity and mortality in SAH patients (Fig. 5, Ref. 11).

  10. Lapachol inhibits glycolysis in cancer cells by targeting pyruvate kinase M2

    OpenAIRE

    Shankar Babu, Mani; Mahanta, Sailendra; Lakhter, Alexander J.; Hato, Takashi; Paul, Subhankar; Naidu, Samisubbu R.

    2018-01-01

    Reliance on aerobic glycolysis is one of the hallmarks of cancer. Although pyruvate kinase M2 (PKM2) is a key mediator of glycolysis in cancer cells, lack of selective agents that target PKM2 remains a challenge in exploiting metabolic pathways for cancer therapy. We report that unlike its structural analog shikonin, a known inhibitor of PKM2, lapachol failed to induce non-apoptotic cell death ferroxitosis in hypoxia. However, melanoma cells treated with lapachol showed a dose-dependent inhib...

  11. Pyruvate Accumulation Is the First Line of Cell Defense against Heat Stress in a Fungus

    OpenAIRE

    Xing Zhang; Raymond J. St. Leger; Weiguo Fang; Michael Lorenz

    2017-01-01

    ABSTRACT Heat tolerance is well known to be key to fungal survival in many habitats, but our mechanistic understanding of how organisms adapt to heat stress is still incomplete. Using Metarhizium robertsii, an emerging model organism for assessing evolutionary processes, we report that pyruvate is in the vanguard of molecules that scavenge heat-induced reactive oxygen species (ROS). We show that, as well as inducing a rapid burst of ROS production, heat stress also downregulates genes for pyr...

  12. Production of d-lactate using a pyruvate-producing Escherichia coli strain.

    Science.gov (United States)

    Akita, Hironaga; Nakashima, Nobutaka; Hoshino, Tamotsu

    2017-07-01

    To generate an organism capable of producing d-lactate, NAD + -dependent d-lactate dehydrogenase was expressed in our pyruvate-producing strain, Escherichia coli strain LAFCPCPt-accBC-aceE. After determining the optimal culture conditions for d-lactate production, 18.4 mM d-lactate was produced from biomass-based medium without supplemental mineral or nitrogen sources. Our results show that d-lactate can be produced in simple batch fermentation processes.

  13. Combination of Aloe vera and xenograft induction on decreasing of NF-kb of tooth extraction socket preservation in Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2014-03-01

    Full Text Available Background: Tooth extraction can naturally cause inflammation triggering osteoclast proliferation and alveolar bone resorption. Preservation of the tooth extraction sockets is needed for patients in order to reduce alveolar bone resorption risks. Aloe vera is known to have anthraquinones components, namely Aloin, Aloe emedin, and barbaloin, considered as anti-inflammation. Therefore, to overcome the inflammation, the role of NF-kb is very significant to decrease nuclear factor kappa b (NF-kb. As a result, inflammation risks will be decreased. Purpose: The study was aimed to determine the induction effect of combination of Aloe vera and XCB into tooth extraction sockets to reduce inflammation by reducing NF-kb expression, osteoclasts and osteoblasts. Methods: Forty-eight Cavia cobaya were divided into eight groups, each group consisted of six animals. The mandibular incisors of those Cavia cobaya were extracted and induced with either PEG, XCB, Aloe vera, or the combination of Aloe vera + XCB. Those animals were sacrificed on day 7 and day 30 after the extraction. Then immunohistochemical and histopathology examinations were conducted to observe NF-kb expression, osteoblasts and osteoclasts. Results: It was known that in group induced with the combination of Aloe vera and xenograft concelous bovine, the growth of osteoblasts was high, while NF-kb expression and osteoclasts reduced. Conclusion: It can be concluded that the induction of the combination of Aloe vera and XCB into the tooth extraction sockets can reduce NF-kb expression and osteoclast, as a result, alveolar bone resorption risks decrease, and osteoblast increase.Latar belakang: Trauma mekanis akibat pencabutan gigi asli menyebabkan keradangan. Keradangan memicu proliferasi osteoklas sehingga menyebabkan resorpsi tulang alveolararis. Pada pembuatan gigi tiruan, resorpsi tulang alveolar yang terjadi, sangat tidak diinginkan, sebab resorpsi tulang alveolar mengurangi keberhasilan

  14. Pyruvate kinase M2 activators promote tetramer formation and suppress tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Anastasiou, Dimitrios; Yu, Yimin; Israelsen, William J.; Jiang, Jian-Kang; Boxer, Matthew B.; Hong, Bum Soo; Tempel, Wolfram; Dimov, Svetoslav; Shen, Min; Jha, Abhishek; Yang, Hua; Mattaini, Katherine R.; Metallo, Christian M.; Fiske, Brian P.; Courtney, Kevin D.; Malstrom, Scott; Khan, Tahsin M.; Kung, Charles; Skoumbourdis, Amanda P.; Veith, Henrike; Southall, Noel; Walsh, Martin J.; Brimacombe, Kyle R.; Leister, William; Lunt, Sophia Y.; Johnson, Zachary R.; Yen, Katharine E.; Kunii, Kaiko; Davidson, Shawn M.; Christofk, Heather R.; Austin, Christopher P.; Inglese, James; Harris, Marian H.; Asara, John M.; Stephanopoulos, Gregory; Salituro, Francesco G.; Jin, Shengfang; Dang, Lenny; Auld, Douglas S.; Park, Hee-Won; Cantley, Lewis C.; Thomas, Craig J.; Vander Heiden, Matthew G.

    2012-08-26

    Cancer cells engage in a metabolic program to enhance biosynthesis and support cell proliferation. The regulatory properties of pyruvate kinase M2 (PKM2) influence altered glucose metabolism in cancer. The interaction of PKM2 with phosphotyrosine-containing proteins inhibits enzyme activity and increases the availability of glycolytic metabolites to support cell proliferation. This suggests that high pyruvate kinase activity may suppress tumor growth. We show that expression of PKM1, the pyruvate kinase isoform with high constitutive activity, or exposure to published small-molecule PKM2 activators inhibits the growth of xenograft tumors. Structural studies reveal that small-molecule activators bind PKM2 at the subunit interaction interface, a site that is distinct from that of the endogenous activator fructose-1,6-bisphosphate (FBP). However, unlike FBP, binding of activators to PKM2 promotes a constitutively active enzyme state that is resistant to inhibition by tyrosine-phosphorylated proteins. This data supports the notion that small-molecule activation of PKM2 can interfere with anabolic metabolism.

  15. Breast Cancer-Derived Lung Metastases Show Increased Pyruvate Carboxylase-Dependent Anaplerosis

    Directory of Open Access Journals (Sweden)

    Stefan Christen

    2016-10-01

    Full Text Available Cellular proliferation depends on refilling the tricarboxylic acid (TCA cycle to support biomass production (anaplerosis. The two major anaplerotic pathways in cells are pyruvate conversion to oxaloacetate via pyruvate carboxylase (PC and glutamine conversion to α-ketoglutarate. Cancers often show an organ-specific reliance on either pathway. However, it remains unknown whether they adapt their mode of anaplerosis when metastasizing to a distant organ. We measured PC-dependent anaplerosis in breast-cancer-derived lung metastases compared to their primary cancers using in vivo 13C tracer analysis. We discovered that lung metastases have higher PC-dependent anaplerosis compared to primary breast cancers. Based on in vitro analysis and a mathematical model for the determination of compartment-specific metabolite concentrations, we found that mitochondrial pyruvate concentrations can promote PC-dependent anaplerosis via enzyme kinetics. In conclusion, we show that breast cancer cells proliferating as lung metastases activate PC-dependent anaplerosis in response to the lung microenvironment.

  16. Recombinant production of Zymomonas mobilis pyruvate decarboxylase in the haloarchaeon Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Steven J. Kaczowka

    2005-01-01

    Full Text Available The unusual physiological properties of archaea (e.g., growth in extreme salt concentration, temperature and pH make them ideal platforms for metabolic engineering. Towards the ultimate goal of modifying an archaeon to produce bioethanol or other useful products, the pyruvate decarboxylase gene of Zymomonas mobilis (Zm pdc was expressed in Haloferax volcanii. This gene has been used successfully to channel pyruvate to ethanol in various Gram-negative bacteria, including Escherichia coli. Although the ionic strength of the H. volcanii cytosol differs over 15-fold from that of E. coli, gel filtration and circular dichroism revealed no difference in secondary structure between the ZmPDC protein isolated from either of these hosts. Like the E. coli purified enzyme, ZmPDC from H. volcanii catalyzed the nonoxidative decarboxylation of pyruvate. A decrease in the amount of soluble ZmPDC protein was detected as H. volcanii transitioned from log phase to late stationary phase that was inversely proportional to the amount of pdc-specific mRNA. Based on these results, proteins from non-halophilic organisms can be actively synthesized in haloarchaea; however, post-transcriptional mechanisms present in stationary phase appear to limit the amount of recombinant protein expressed.

  17. FORMATE-PYRUVATE EXCHANGE REACTION IN STREPTOCOCCUS FAECALIS. I. FACTOR REQUIREMENT FOR INTACT CELLS.

    Science.gov (United States)

    WOOD, N P; O'KANE, D J

    1964-01-01

    Wood, N. P. (A. & M. College of Texas, College Station), and D. J. O'Kane. Formate-pyruvate exchange reaction in Streptococcus faecalis. I. Factor requirement for whole cells. J. Bacteriol. 87:97-103. 1964.-A factor present in plant and animal sources was found necessary for the incorporation of formate-C(14) into pyruvate by Streptococcus faecalis 10Cl. Yeast extract produced a response linear in the range between 10 and 30 mg/ml of reaction mixture. Soy peptone, beef peptone, and Brain Heart Infusion replaced yeast extract, but various intermediates, cofactors, amino acids, purines, pyrimidines, and peptides did not stimulate the reaction. A lag occurred in the rate of formate incorporation that was not influenced by anaerobic conditions or growth of cells in a medium containing pyruvate and formate. Phosphate or maleate buffer permitted rapid exchange velocities but tris(hydroxymethyl)aminomethane or collidine buffer was inhibitory. Heating yeast extract at 121 C for 15 min in 3 n H(2)SO(4) produced 66% inactivation of the factor(s), whereas treatment with 3 n KOH produced 97% inactivation. The factor(s) was insoluble in butanol, benzene, ethyl acetate, or chloroform. The material adsorbed on Dowex-1 (OH(-)) and Amberlite IR-120 (H(+)) but not on Amberlite IR-4B (OH(-)). The active component(s) was highly polar, nonvolatile, dialyzable, and had amphoteric properties.

  18. Field dependence of T1 for hyperpolarized [1-13C]pyruvate

    DEFF Research Database (Denmark)

    Chattergoon, N.; Martnez-Santiesteban, F.; Handler, W. B.

    2013-01-01

    In vivo metabolism of hyperpolarized pyruvate has been demonstrated to be an important probe of cellular glycolysis in diseases such as cancer. The usefulness of hyperpolarized 13C imaging is dependent on the relaxation rates of the 13C-enriched substrates, which in turn depend on chemical...... conformation and properties of the dissolution media such as buffer composition, solution pH, temperature and magnetic field. We have measured the magnetic field dependence of the spin–lattice relaxation time of hyperpolarized [1-13C]pyruvate using field-cycled relaxometry. [1-13C]pyruvate was hyperpolarized...... using dynamic nuclear polarization and then rapidly thawed and dissolved in a buffered solution to a concentration of 80 mmol l−1 and a pH of ~7.8. The hyperpolarized liquid was transferred within 8 s to a fast field-cycling relaxometer with a probe tuned for detection of 13C at a field strength of ~0...

  19. Gas-Phase Photolysis of Pyruvic Acid: The Effect of Pressure on Reaction Rates and Products.

    Science.gov (United States)

    Reed Harris, Allison E; Doussin, Jean-Francois; Carpenter, Barry K; Vaida, Veronica

    2016-12-29

    In this work, we investigate the impact of pressure and oxygen on the kinetics of and products from the gas-phase photolysis of pyruvic acid. The results reveal a decrease in the photolysis quantum yield as pressure of air or nitrogen is increased, a trend not yet documented in the literature. A Stern-Volmer analysis demonstrates this effect is due to deactivation of the singlet state of pyruvic acid when the photolysis is performed in nitrogen, and from quenching of both the singlet and triplet state in air. Consistent with previous studies, acetaldehyde and CO 2 are observed as the major products; however, other products, most notably acetic acid, are also identified in this work. The yield of acetic acid increases with increasing pressure of buffer gas, an effect that is amplified by the presence of oxygen. At least two mechanisms are necessary to explain the acetic acid, including one that requires reaction of photolysis intermediates with O 2 . These findings extend the fundamental understanding of the gas-phase photochemistry of pyruvic acid, highlighting the importance of pressure on the photolysis quantum yields and products.

  20. Kinetic and Thermodynamic Analysis of Acetyl-CoA Activation of Staphylococcus aureus Pyruvate Carboxylase.

    Science.gov (United States)

    Westerhold, Lauren E; Bridges, Lance C; Shaikh, Saame Raza; Zeczycki, Tonya N

    2017-07-11

    Allosteric regulation of pyruvate carboxylase (PC) activity is pivotal to maintaining metabolic homeostasis. In contrast, dysregulated PC activity contributes to the pathogenesis of numerous diseases, rendering PC a possible target for allosteric therapeutic development. Recent research efforts have focused on demarcating the role of acetyl-CoA, one of the most potent activators of PC, in coordinating catalytic events within the multifunctional enzyme. Herein, we report a kinetic and thermodynamic analysis of acetyl-CoA activation of the Staphylococcus aureus PC (SaPC)-catalyzed carboxylation of pyruvate to identify novel means by which acetyl-CoA synchronizes catalytic events within the PC tetramer. Kinetic and linked-function analysis, or thermodynamic linkage analysis, indicates that the substrates of the biotin carboxylase and carboxyl transferase domain are energetically coupled in the presence of acetyl-CoA. In contrast, both kinetic and energetic coupling between the two domains is lost in the absence of acetyl-CoA, suggesting a functional role for acetyl-CoA in facilitating the long-range transmission of substrate-induced conformational changes within the PC tetramer. Interestingly, thermodynamic activation parameters for the SaPC-catalyzed carboxylation of pyruvate are largely independent of acetyl-CoA. Our results also reveal the possibility that global conformational changes give rise to observed species-specific thermodynamic activation parameters. Taken together, our kinetic and thermodynamic results provide a possible allosteric mechanism by which acetyl-CoA coordinates catalysis within the PC tetramer.

  1. Cold Lability of Pyruvate, Orthophosphate Dikinase in the Maize Leaf 1

    Science.gov (United States)

    Shirahashi, Kenji; Hayakawa, Shinobu; Sugiyama, Tatsuo

    1978-01-01

    Cold lability of pyruvate, orthophosphate dikinase was investigated using a homogeneous, purified enzyme preparation from maize (Zea mays L. var. Golden Cross Bantam T51) leaves. Its stability was markedly reduced below about 10 C and the rate of cold inactivation followed first order kinetics at a concentration lower than about 0.1 milligram of enzyme per milliliter. Cold inactivation was little affected by pH in the range which gives good stability for the enzyme at warm temperatures and the enzyme activity was protected strongly by inclusion of substrates (pyruvate and phosphoenolpyruvate) and polyols such as sucrose, sorbitol, and glycerol. Loss of catalytic activity was accompanied by an apparent dissociation of a tetrameric form of the enzyme (9S form) into a new, more slowly sedimenting (5.1S) component. Inclusion of pyruvate at 4 mM in the cold-treated enzyme had no effect on the sedimentation value. A sharp change in activation energy of the dikinase-catalyzed reaction was observed near 12 C and its break point appears to be close to the generally accepted critical low temperature limit for the growth of maize plants. ImagesFig. 6 PMID:16660615

  2. Stem Cell Metabolism in Cancer and Healthy Tissues: Pyruvate in the Limelight

    Directory of Open Access Journals (Sweden)

    Cyril Corbet

    2018-01-01

    Full Text Available Normal and cancer stem cells (CSCs share the remarkable potential to self-renew and differentiate into many distinct cell types. Although most of the stem cells remain under quiescence to maintain their undifferentiated state, they can also undergo cell divisions as required to regulate tissue homeostasis. There is now a growing evidence that cell fate determination from stem cells implies a fine-tuned regulation of their energy balance and metabolic status. Stem cells can shift their metabolic substrate utilization, between glycolysis and mitochondrial oxidative metabolism, during specification and/or differentiation, as well as in order to adapt their microenvironmental niche. Pyruvate appears as a key metabolite since it is at the crossroads of cytoplasmic glycolysis and mitochondrial oxidative phosphorylation. This Review describes how metabolic reprogramming, focusing on pyruvate utilization, drives the fate of normal and CSCs by modulating their capacity for self-renewal, clonal expansion/differentiation, as well as metastatic potential and treatment resistance in cancer. This Review also explores potential therapeutic strategies to restore or manipulate stem cell function through the use of small molecules targeting the pyruvate metabolism.

  3. Single Sodium Pyruvate Ingestion Modifies Blood Acid-Base Status and Post-Exercise Lactate Concentration in Humans

    Directory of Open Access Journals (Sweden)

    Robert A. Olek

    2014-05-01

    Full Text Available This study examined the effect of a single sodium pyruvate ingestion on a blood acid-base status and exercise metabolism markers. Nine active, but non-specifically trained, male subjects participated in the double-blind, placebo-controlled, crossover study. One hour prior to the exercise, subjects ingested either 0.1 g·kg−1 of body mass of a sodium pyruvate or placebo. The capillary blood samples were obtained at rest, 60 min after ingestion, and then three and 15 min after completing the workout protocol to analyze acid-base status and lactate, pyruvate, alanine, glucose concentrations. The pulmonary gas exchange, minute ventilation and the heart rate were measured during the exercise at a constant power output, corresponding to ~90% O2max. The blood pH, bicarbonate and the base excess were significantly higher after sodium pyruvate ingestion than in the placebo trial. The blood lactate concentration was not different after the ingestion, but the post-exercise was significantly higher in the pyruvate trial (12.9 ± 0.9 mM than in the placebo trial (10.6 ± 0.3 mM, p < 0.05 and remained elevated (nonsignificant after 15 min of recovery. The blood pyruvate, alanine and glucose concentrations, as well as the overall pulmonary gas exchange during the exercise were not affected by the pyruvate ingestion. In conclusion, the sodium pyruvate ingestion one hour before workout modified the blood acid-base status and the lactate production during the exercise.

  4. Incorporation of C14 pyruvate and C14-α-ketoglutarate in alanine and glutamic acid in isolated chloroplasts

    International Nuclear Information System (INIS)

    Tsenova, E.N.; Vaklinova, S.G.

    1974-01-01

    Peas chloroplasts were used. Experiments were carried out with C 14 -pyruvate and C 14 -α-ketoglutarate. The results presented in this report constitute direct demonstration for the fact that in a system of isolated chloroplasts, in the presence of ammonium ions, the C 14 -pyruvate and the C 14 -α-ketoglutarate can be used directly for the synthesis of alanine and glutamic acid as ketoanalogus of these amino acids. (M.Ts.)

  5. The effect of antioxidant treatment on blood lactate and pyruvate concentrations in a rabbit model of obesity

    Directory of Open Access Journals (Sweden)

    N. Grigorova

    2017-03-01

    Full Text Available In the current study, the impact of dietary antioxidant supplementation on fasting blood lactate and pyruvate concentrations in a rabbit model of obesity was investigated. A total of 26 rabbits were randomly divided into 3 groups: castrated and obese animals (CO, n=7; castrated, obese and treated with antioxidants (Immunoprotect, n=7, CIm and non-castrated, non-treated controls (NC, n=12. At the end of the 2-month treatment period blood lactate concentration, lactate to pyruvate and lactate to glucose ratio in CIm were significantly (P<0.05 lower than in NC and tended to be lower than in CO. No group differences in pyruvate and glucose concentrations were found. There was a significant negative (r =–0.53; P<0.05 correlation between lactate and glucose concentrations. On the other hand, lactate was correlated significantly positively with pyruvate (r=0.72; P<0.01, lactate to pyruvate ratio (r=0.94; P<0.001, lactate to glucose ratio (r=0.75; P<0.001 and pyruvate to glucose ratio (r=0.81; P<0.001. In conclusion, the decrease of blood lactate concentration in antioxi-dant treated rabbits could be considered as a mechanism for improvement of skeletal muscle insulin sensitivity. In addition, antioxidant treatment could be used as an alternative tool to counteract lactic acidosis in obesity and diabetes.

  6. Study on the protective effect of ethyl pyruvate on mouse models of sepsis-induced lung injury

    International Nuclear Information System (INIS)

    Ti Dongdong; Deng Zihui; Xue Hui; Wang Luhuan; Lin Ji; Yan Guangtao

    2008-01-01

    Objective: To investigate the protective role of ethyl pyruvate on mouse models of lung injury from sepsis. Methods: Mouse sepsis models were established by cecal ligation-perforation. Four enzyme parameters related to synthesis of free radicals in lung homogenized fluids namely malonaldehyde (MDA), pyruvate acid, lactic acid and total anti-oxidative capacity (TAOC) were determined with spectrophotometry, and serum leptin levels were detected with radioimmunoassay at 3, 6, 9, 12h after operation in these models. Half of the models were treated with intraperitoneal injection of ethyl pyruvate (EP) (75mg/kg). Results: In the models treated with ethyl pyruvate injection, the activity of malonaldehyde, pyruvate acid, lactic acid and total anti-oxidative capacity were affected to certain extent, at some time frames but the results were not unanimously inhibitive or promotive. Serum leptin levels in EP injection models at 6h and 12h after sepsis were significantly higher than those in non-treated models. Conclusion: Ethyl pyruvate perhaps exerted its protective effect on sepsis-induced lung injury through increase of leptin levels in the models. (authors)

  7. Hyperpolarized [1-(13) C]pyruvate MRI for noninvasive examination of placental metabolism and nutrient transport: A feasibility study in pregnant guinea pigs.

    Science.gov (United States)

    Friesen-Waldner, Lanette J; Sinclair, Kevin J; Wade, Trevor P; Michael, Banoub; Chen, Albert P; de Vrijer, Barbra; Regnault, Timothy R H; McKenzie, Charles A

    2016-03-01

    To test the feasibility of hyperpolarized [1-(13) C]pyruvate magnetic resonance imaging (MRI) for noninvasive examination of guinea pig fetoplacental metabolism and nutrient transport. Seven pregnant guinea pigs with a total of 30 placentae and fetuses were anesthetized and scanned at 3T. T1 -weighted (1) H images were obtained from the maternal abdomen. An 80 mM solution of hyperpolarized [1-(13) C]pyruvate (hereafter referred to as pyruvate) was injected into a vein in the maternal foot. Time-resolved 3D (13) C images were acquired starting 10 seconds after the beginning of bolus injection and every 10 seconds after to 50 seconds. The pregnant guinea pigs were recovered after imaging. Regions of interest (ROIs) were drawn around the maternal heart and each placenta and fetal liver in all slices in the (1) H images. These ROIs were copied to the (13) C images and were used to calculate the sum of the pyruvate and lactate signal intensities for each organ. The signal intensities were normalized by the volume of the organ and the maximum signal in the maternal heart. No adverse events were observed in the pregnant guinea pigs and natural pupping occurred at term (∼68 days). Pyruvate signal was observed in all 30 placentae, and lactate, a by-product of pyruvate metabolism, was also observed in all placentae. The maximum pyruvate and lactate signals in placentae occurred at 20 seconds. In addition to the observation of pyruvate and lactate signals in the placentae, both pyruvate and lactate signals were observed in all fetal livers. The maximum pyruvate and lactate signals in the fetal livers occurred at 10 seconds and 20 seconds, respectively. This work demonstrates the feasibility of using hyperpolarized [1-(13) C]pyruvate MRI to noninvasively examine fetoplacental metabolism and transport of pyruvate in guinea pigs. Hyperpolarized (13) C MRI may provide a novel method for longitudinal studies of fetoplacental abnormalities. © 2015 Wiley Periodicals, Inc.

  8. Stem cell selection in vivo using foamy vectors cures canine pyruvate kinase deficiency.

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    Grant D Trobridge

    Full Text Available Hematopoietic stem cell (HSC gene therapy has cured immunodeficiencies including X-linked severe combined immunodeficiency (SCID-X1 and adenine deaminase deficiency (ADA. For these immunodeficiencies corrected cells have a selective advantage in vivo, and low numbers of gene-modified cells are sufficient to provide therapeutic benefit. Strategies to efficiently transduce and/or expand long-term repopulating cells in vivo are needed for treatment of diseases that require higher levels of corrected cells, such as hemoglobinopathies. Here we expanded corrected stem cells in vivo in a canine model of a severe erythroid disease, pyruvate kinase deficiency.We used a foamy virus (FV vector expressing the P140K mutant of methylguanine methyltransferase (MGMTP140K for in vivo expansion of corrected hematopoietic repopulating cells. FV vectors are attractive gene transfer vectors for hematopoietic stem cell gene therapy since they efficiently transduce repopulating cells and may be safer than more commonly used gammaretroviral vectors. Following transplantation with HSCs transduced ex vivo using a tri-cistronic FV vector that expressed EGFP, R-type pyruvate kinase, and MGMTP140K, we were able to increase marking from approximately 3.5% to 33% in myeloid long-term repopulating cells resulting in a functional cure.Here we describe in one affected dog a functional cure for a severe erythroid disease using stem cell selection in vivo. In addition to providing a potential cure for patients with pyruvate kinase deficiency, in vivo selection using foamy vectors with MGMTP140K has broad potential for several hematopoietic diseases including hemoglobinopathies.

  9. Maturation of pig oocytes in vitro in a medium with pyruvate

    Directory of Open Access Journals (Sweden)

    H. Gonzales-Figueroa

    2005-06-01

    Full Text Available The aim of in vitro maturation oocyte systems is to produce oocytes of comparable quality to those derived in vivo. The present study was designed to examine the surface morphological changes of the cumulus-oocyte complex (COC and nuclear maturation in a culture system containing pyruvate. Ovaries were obtained from a slaughterhouseand transported to the laboratory within 2 h at 35-39ºC,and rinsed three times in 0.9% NaCl. The COCs were harvested from the ovaries and in vitro maturation was evaluated in San Marcos (SM medium, a chemically defined culture system containing 22.3 mM sodium pyruvate. Oocytes were cultured in SM, SM + porcine follicular fluid (pFF and in SM + pFF + gonadotropins (eCG and hCG for 20-22 h and then without hormonal supplements for an additional 20-22 h. After culture, the degree of cumulus expansion and frequency of nuclear maturation were determined. Oocytes matured in SM (40.9% and SM + pFF (42.9% showed moderate cumulus expansion, whereas oocytes matured in SM + pFF + gonadotropins (54.6% showed high cumulus expansion. The maturation rate of cultured oocytes, measured in function of the presence of the polar corpuscle, did not differ significantly between SM (40.9 ± 3.6% and SM + pFF (42.9 ± 3.7%. These results indicate that pig oocytes can be successfully matured in a chemically definedmedium and suggest a possible bifunctional role of pyruvate as an energy substrate and as an antioxidant protecting oocytes against the stress of the in vitro environment.

  10. Domain interaction in rabbit muscle pyruvate kinase. II. Small angle neutron scattering and computer simulation.

    Science.gov (United States)

    Consler, T G; Uberbacher, E C; Bunick, G J; Liebman, M N; Lee, J C

    1988-02-25

    The effects of ligands on the structure of rabbit muscle pyruvate kinase were studied by small angle neutron scattering. The radius of gyration, RG, decreases by about 1 A in the presence of the substrate phosphoenolpyruvate, but increases by about the same magnitude in the presence of the allosteric inhibitor phenylalanine. With increasing pH or in the absence of Mg2+ and K+, the RG of pyruvate kinase increases. Hence, there is a 2-A difference in RG between two alternative conformations. Length distribution analysis indicates that, under all experimental conditions which increase the radius of gyration, there is a pronounced increase observed in the probability for interatomic distance between 80 and 110 A. These small angle neutron scattering results indicate a "contraction" and "expansion" of the enzyme when it transforms between its active and inactive forms. Using the alpha-carbon coordinates of crystalline cat muscle pyruvate kinase, a length distribution profile was calculated, and it matches the scattering profile of the inactive form. These observations are expected since the crystals were grown in the absence of divalent cations (Stuart, D. I., Levine, M., Muirhead, H., and Stammers, D. K. (1979) J. Mol. Biol. 134, 109-142). Hence, results from neutron scattering, x-ray crystallographic, and sedimentation studies (Oberfelder, R. W., Lee, L. L.-Y., and Lee, J.C. (1984) Biochemistry 23, 3813-3821) are totally consistent with each other. With the aid of computer modeling, the crystal structure has been manipulated in order to effect changes that are consistent with the conformational change described by the solution scattering data. The structural manipulation involves the rotation of the B domain relative to the A domain, leading to the closure of the cleft between these domains. These manipulations resulted in the generation of new sets of atomic (C-alpha) coordinates, which were utilized in calculations, the result of which compared favorably with the

  11. Protective Effect of Pyruvate Against Radiation-Induced Damage in Collagenized Tissues

    Science.gov (United States)

    Griko, Y. V.; Yan, Xiaoli

    2016-01-01

    Exposure to high doses of ionizing radiation produces both acute and late effects on the collagenized tissues and have profound effects on wound healing. Because of the crucial practical importance for new radioprotective agents, our study has been focused on evaluation of the efficacy of non-toxic naturally occurring compounds to protect tissue integrity against high-dose gamma radiation. Here, we demonstrate that molecular integrity of collagen may serve as a sensitive biological marker for quantitative evaluation of molecular damage to collagenized tissue and efficacy of radioprotective agents. Increasing doses of gamma radiation (0-50kGy) result in progressive destruction of the native collagen fibrils, which provide a structural framework, strength, and proper milieu for the regenerating tissue. The strategy used in this study involved the thermodynamic specification of all structural changes in collagenized matrix of skin, aortic heart valve, and bone tissue induced by different doses and conditions of g-irradiation. This study describes a simple biophysical approach utilizing the Differential Scanning Calorimetry (DSC) to characterize the structural resistance of the aortic valve matrix exposed to different doses of g-irradiation. It allows us to identify the specific response of each constituent as well as to determine the influence of the different treatments on the characteristic parameters of protein structure. We found that pyruvate, a substance that naturally occurs in the body, provide significant protection (up to 80%) from biochemical and biomechanical damage to the collagenized tissue through the effective targeting of reactive oxygen species. The recently discovered role of pyruvate in the cell antioxidant defense to O2 oxidation, and its essential constituency in the daily human diet, indicate that the administration of pyruvate-based radioprotective formulations may provide safe and effective protection from deleterious effects of ionizing

  12. Comparison the effectiveness of pyruvic acid 50% and salicylic acid 30% in the treatment of acne

    Directory of Open Access Journals (Sweden)

    Fariba Jaffary

    2016-01-01

    Full Text Available Background: Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles and one of the most common skin diseases. The peeling method has been recently found to be effective for acne treatment. This study aimed to compare the efficacy of pyruvic acid 50% and salicylic acid 30% peeling in the treatment of mild to moderate acne. Materials and Methods: In a prospective single-blinded clinical trial, 86 patients with acne were randomly assigned into two groups. In both groups, the routine treatment of acne (topical solution of erythromycin 4%, triclorocarban soap, and sunscreen were used twice a day for 8 weeks. In addition, salicylic acid 30% for the control group and pyruvic acid 50% for the case group were used. In both groups, acne severity index (ASI was calculated before and at week 2, 4, 6, and 8 of the treatment. Patient satisfaction was assessed at the end of the treatment. Side effects were recorded using a checklist. Results: In both groups, the reduction in the number of comedones, papules, and ASI were statistically significant (P < 0.001 in the course of treatment. However, it was not significant regarding the number of pustules (P = 0.09. None of the number of comedone, papules, pustules, and ASI was statistically different between study groups. Both treatment groups had similar side effects except for scaling in the fifth session, which was significantly lower in salicylic acid - treated patients (P = 0.015. Conclusion: Both pyruvic acid 50% and salicylic acid 30% are effective in the improvement of mild to moderate acne with no significant difference in efficacy and side effects.

  13. Specific Arabidopsis thaliana malic enzyme isoforms can provide anaplerotic pyruvate carboxylation function in Saccharomyces cerevisiae.

    Science.gov (United States)

    Badia, Mariana Beatriz; Mans, Robert; Lis, Alicia V; Tronconi, Marcos Ariel; Arias, Cintia Lucía; Maurino, Verónica Graciela; Andreo, Carlos Santiago; Drincovich, María Fabiana; van Maris, Antonius J A; Gerrard Wheeler, Mariel Claudia

    2017-02-01

    NAD(P)-malic enzyme (NAD(P)-ME) catalyzes the reversible oxidative decarboxylation of malate to pyruvate, CO 2 , and NAD(P)H and is present as a multigene family in Arabidopsis thaliana. The carboxylation reaction catalyzed by purified recombinant Arabidopsis NADP-ME proteins is faster than those reported for other animal or plant isoforms. In contrast, no carboxylation activity could be detected in vitro for the NAD-dependent counterparts. In order to further investigate their putative carboxylating role in vivo, Arabidopsis NAD(P)-ME isoforms, as well as the NADP-ME2del2 (with a decreased ability to carboxylate pyruvate) and NADP-ME2R115A (lacking fumarate activation) versions, were functionally expressed in the cytosol of pyruvate carboxylase-negative (Pyc - ) Saccharomyces cerevisiae strains. The heterologous expression of NADP-ME1, NADP-ME2 (and its mutant proteins), and NADP-ME3 restored the growth of Pyc - S. cerevisiae on glucose, and this capacity was dependent on the availability of CO 2 . On the other hand, NADP-ME4, NAD-ME1, and NAD-ME2 could not rescue the Pyc - strains from C 4 auxotrophy. NADP-ME carboxylation activity could be measured in leaf crude extracts of knockout and overexpressing Arabidopsis lines with modified levels of NADP-ME, where this activity was correlated with the amount of NADP-ME2 transcript. These results indicate that specific A. thaliana NADP-ME isoforms are able to play an anaplerotic role in vivo and provide a basis for the study on the carboxylating activity of NADP-ME, which may contribute to the synthesis of C 4 compounds and redox shuttling in plant cells. © 2017 Federation of European Biochemical Societies.

  14. The effect of combined Moringa oleifera and demineralized freeze-dried bovine bone xenograft on the amount of osteoblast and osteoclast in the healing of tooth extraction socket of Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Rostiny Rostiny

    2016-12-01

    Full Text Available Background: Alveolar bone has an important role in providing support to teeth and dentures. Loss of support caused by alveolar resorption will cause functional and aesthetic problems. Preservation socket using bone graft is one way to maintain the dimensions of the alveolar bone. Moringa oleifera leaf can increase the activity of bone graft in the formation of new bone. Purpose: This study was aimed to evaluate the effect of combined Moringa oleivera leaf extract and demineralized freeze-dried bovine bone xenograft (DFDBBX towards the formation of osteoblasts and osteoclasts in the tooth extraction sockets of cavia cobaya. Method: This study used 28 cavia cobayas divided into four groups. The combination of Moringa oleifera leaf extract and DFDBBX was inducted into the sockets of lower incisor tooth with certain dose in each group, ointment 1 containing PEG (a mixture of PEG 400 and PEG 4000 for control group, ointment 2 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active subtance consentration of 0.5% for group 1, ointment 3 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance concentration of 1% for group 2, and Ointment 4 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance consentration of 2% for group 3. paraffin block preparations were made for histopathology examination using hematoxylin eosin staining. Result: The results showed that there were significant differences of the number of osteoblasts and osteoclasts in each treatment group (p <0.05. Conclusion: It can be concluded that the combination of Moringa oleifera leaf extract and DFDBBX at 2% cocentration can increase the number of osteoblasts and decrease osteoclasts in the healing of tooth extraction sockets of cavia cobaya.

  15. Hyperpolarized 1-13C Pyruvate Imaging of Porcine Cardiac Metabolism shift by GIK Intervention

    DEFF Research Database (Denmark)

    Søvsø Szocska Hansen, Esben; Tougaard, Rasmus Stilling; Mikkelsen, Emmeli

    Cardiac metabolism has gained considerable attention worldwide lately, both as a diagnostic and prognostication tool, as well as a novel target for treatment. As human trials involving hyperpolarized MR in the heart are imminent, we employed a clinically relevant, large animal model, and sought...... to evaluate the general feasibility to detect an imposed shift in metabolic substrate utilization during metabolic modulation with glucose, insulin and potassium (GIK) infusion. This study demonstrates that hyperpolarized 13C-pyruvate, in a large animal, is a feasible method for cardiac studies, and...

  16. Cloning and sequencing of pyruvate decarboxylase (PDC) genes from bacteria and uses therefor

    Science.gov (United States)

    Maupin-Furlow, Julie A [Gainesville, FL; Talarico, Lee Ann [Gainesville, FL; Raj, Krishnan Chandra [Tamil Nadu, IN; Ingram, Lonnie O [Gainesville, FL

    2008-02-05

    The invention provides isolated nucleic acids molecules which encode pyruvate decarboxylase enzymes having improved decarboxylase activity, substrate affinity, thermostability, and activity at different pH. The nucleic acids of the invention also have a codon usage which allows for high expression in a variety of host cells. Accordingly, the invention provides recombinant expression vectors containing such nucleic acid molecules, recombinant host cells comprising the expression vectors, host cells further comprising other ethanologenic enzymes, and methods for producing useful substances, e.g., acetaldehyde and ethanol, using such host cells.

  17. Inborn Errors of Metabolism with Acidosis: Organic Acidemias and Defects of Pyruvate and Ketone Body Metabolism.

    Science.gov (United States)

    Schillaci, Lori-Anne P; DeBrosse, Suzanne D; McCandless, Shawn E

    2018-04-01

    When a child presents with high-anion gap metabolic acidosis, the pediatrician can proceed with confidence by recalling some basic principles. Defects of organic acid, pyruvate, and ketone body metabolism that present with acute acidosis are reviewed. Flowcharts for identifying the underlying cause and initiating life-saving therapy are provided. By evaluating electrolytes, blood sugar, lactate, ammonia, and urine ketones, the provider can determine the likelihood of an inborn error of metabolism. Freezing serum, plasma, and urine samples during the acute presentation for definitive diagnostic testing at the provider's convenience aids in the differential diagnosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Structural Basis for Flip-Flop Action of Thiamin-Dependent Enzymes Revealed by Crystal Structure of Human Pyruvate Dehydrogenase

    Science.gov (United States)

    Ciszak, Ewa; Korotchkina, Lioubov G.; Dominiak, Paulina M.; Sidhu, Sukdeep; Patel, Mulchand S.

    2003-01-01

    The biologically active derivative of vitamin B1; thiamin pyrophosphate; is used as cofactor by many enzymes that perform a wide range of catalytic functions in the pathways of energy production. In alpha2beta2-heterotetrameric human pyruvate dehydrogenase, the first catalytic component enzyme of human pyruvate dehydrogenase complex, this cofactor is used to cleave the C(sup alpha)-C(=0) bond of pyruvate followed by reductive acetyl transfer to lipoyl-dihydrolipoamide acetyltransferase, the second catalytic component of the complex. The dynamic nonequivalence of two, otherwise chemically equivalent, catalytic sites have puzzled researchers from earlier functional studies of this enzyme. In order to gain insight into the mechanism of action of this enzyme, we determined the crystal structure of the holoform of human pyruvate dehydrogenase at 1.958, resolution. We propose a kinetic model for the flip-flop action of this enzyme through the concerted approx. 2A, shuttle-like motion of the heterodimers. The similarity of thiamin pyrophosphate binding in human pyruvate dehydrogenase and other functionally related enzymes suggests this newly defined mechanism of shuttle-like motion of domains to be common for the family of thiamin pyrophosphate-dependent enzymes.

  19. Comparison of two metal-dependent pyruvate aldolases related by convergent evolution: substrate specificity, kinetic mechanism, and substrate channeling.

    Science.gov (United States)

    Wang, Weijun; Baker, Perrin; Seah, Stephen Y K

    2010-05-04

    HpaI and BphI are two pyruvate class II aldolases found in aromatic meta-cleavage degradation pathways that catalyze similar reactions but are not related in sequence. Steady-state kinetic analysis of the aldol addition reactions and product inhibition assays showed that HpaI exhibits a rapid equilibrium random order mechanism while BphI exhibits a compulsory order mechanism, with pyruvate binding first. Both aldolases are able to utilize aldehyde acceptors two to five carbons in length; however, HpaI showed broader specificity and had a preference for aldehydes containing longer linear alkyl chains or C2-OH substitutions. Both enzymes were able to bind 2-keto acids larger than pyruvate, but only HpaI was able to utilize both pyruvate and 2-ketobutanoate as carbonyl donors in the aldol addition reaction. HpaI lacks stereospecific control producing racemic mixtures of 4-hydroxy-2-oxopentanoate (HOPA) from pyruvate and acetaldehyde while BphI synthesizes only (4S)-HOPA. BphI is also able to utilize acetaldehyde produced by the reduction of acetyl-CoA catalyzed by the associated aldehyde dehydrogenase, BphJ. This aldehyde was directly channeled from the dehydrogenase to the aldolase active sites, with an efficiency of 84%. Furthermore, the BphJ reductive deacylation reaction increased 4-fold when BphI was catalyzing the aldol addition reaction. Therefore, the BphI-BphJ enzyme complex exhibits unique bidirectionality in substrate channeling and allosteric activation.

  20. Difference of 14C turnovers in brain and in transplanted glioma after intravenous injection of 14C-1-pyruvate rats

    International Nuclear Information System (INIS)

    Hara, Toshihiko; Yokoi, Fuji

    1986-01-01

    Carbon 14 from 14 C-1-pyruvate injected intravenously into glioma-transplanted rats was incorporated into various compounds in the brain and in the tumor. In the brain the majority of activity was found in CO 2 (60%), and minor activities were found in alanine, lactate (15%), glutamate, and aspartate, with decreasing order, 5 min after injection. In the tumor, at 5 min. the largest activity was in lactate (56%), and lower activities were found in CO 2 (24%), alanine, glutamate, and aspartate. The total 14 C concentration in the tumor was twice that in the brain at 5 min and 15 min. The results was in accordance with the prediction that in brain, where the mitochondrial function is active, 14 C-1-pyruvate will be oxidized completely into 14 CO 2 , and that in tumor, where the mitochondrial function is insufficient, 14 C-1-pyruvate will be converted only into 14 C-lactate and prevent further degradation. It may be assumed that this difference in the turnover of 14 C and 14 C-1-pyruvate between brain and tumor could constitute a basis for the ''hot'' visualization of human brain tumor using cyclotron-produced 11 C-1-pyruvate and positron-emission tomography. (orig.)

  1. [Development and analytical validation according COFRAC recommendations of pyruvate and ketone body assay on open automated analyser].

    Science.gov (United States)

    Boulet, Lysiane; Van Noolen, Laetitia; Bosson, Caroline; Faure, Patrice; Corne, Christelle

    2014-01-01

    Measurements of pyruvate and ketones bodies (acetoacetate and 3-hydroxybutyrate) are essential to the investigation of intermediary metabolism. Indeed, their blood levels reflect energy balance influenced by nutritional status. This balance can be disturbed in certain diseases such as diabetes and some inherited metabolic disorders. We have developed methods for assays on open automated biochemistry analyser, Konelab 20 XT (ThermoFischer, Whaltham USA), using kits marketed by Sobioda (Montbonnot, France) for pyruvate and Wako Chemicals GmbH (Neuss, Germany) for ketones, on deproteinised blood sample. We have validated the performance of these three quantitative methods using NF EN ISO 15189 (range B) standard criteria. We obtain satisfactory results concerning fidelity (precision measured as within and between batch CVs are respectively less than 7% and less than 6%), measuring ranges (from 7.7 to 228 μmol/L for pyruvate and from 22.6 to 650 μM for total ketone bodies), accuracy (10.4 μmol/L in physiological range for pyruvate and 7.1 μmol/L for 3-hydroxybutyrate) and comparing methods (versus manual assay with spectrophotometry on Uvikon XL). Establishment of reference ranges (35 to 74 μmol/L for pyruvate, less than 100 μM for 3-hydroxybutyrate and less than 44 μmol/L for acetoacetate) and reagents stability study (up to 12 weeks if frozen) have enabled us to finalize method validation and to add these assays to our routine laboratory repertoire.

  2. Structure function studies on the lipoate-acetyltransferase--component-X-core assembly of the ox heart pyruvate dehydrogenase complex.

    Science.gov (United States)

    Hodgson, J A; De Marcucci, O G; Lindsay, J G

    1988-02-01

    Component X, the recently recognised subunit of mammalian pyruvate dehydrogenase complex, was shown by immune blotting to be present in all of nine tissues dissected from rat. This finding indicated that component X was not an isoenzyme of the lipoate acetyltransferase (E2) associated with one or a limited number of tissues. Native pyruvate dehydrogenase complex was shown to bind IgG raised to isolated component X, indicating that there were at least some regions of the X subunit exposed at the periphery of the complex. Lipoyl groups of ox heart pyruvate dehydrogenase complex were specifically cross-linked by reaction with phenylene-o-bismaleimide in the presence of pyruvate and the subunits contributing to the products of cross-linking were identified by immune blotting. Species with very high Mr containing both E2 and component X, were formed in high yield, as well as apparent E2/E2 and E2/X dimers and trimers and an X/X dimer. These results showed that acetylated lipoyl groups of different E2 and X subunits were able to interact in all possible combinations. The types of cross-linked E2 products formed suggested that two thiols, reactible with phenylene-o-bismaleimide, were rapidly generated in the presence of pyruvate. The results were most easily explained by the presence of two acetylatable lipoyl groups on each E2 polypeptide.

  3. Kinetic simulation of malate-aspartate and citrate-pyruvate shuttles in association with Krebs cycle.

    Science.gov (United States)

    Korla, Kalyani; Vadlakonda, Lakshmipathi; Mitra, Chanchal K

    2015-01-01

    In the present work, we have kinetically simulated two mitochondrial shuttles, malate-aspartate shuttle (used for transferring reducing equivalents) and citrate-pyruvate shuttle (used for transferring carbon skeletons). However, the functions of these shuttles are not limited to the points mentioned above, and they can be used in different arrangements to meet different cellular requirements. Both the shuttles are intricately associated with Krebs cycle through the metabolites involved. The study of this system of shuttles and Krebs cycle explores the response of the system in different metabolic environments. Here, we have simulated these subsets individually and then combined them to study the interactions among them and to bring out the dynamics of these pathways in focus. Four antiports and a pyruvate pump were modelled along with the metabolic reactions on both sides of the inner mitochondrial membrane. Michaelis-Menten approach was extended for deriving rate equations of every component of the system. Kinetic simulation was carried out using ordinary differential equation solver in GNU Octave. It was observed that all the components attained steady state, sooner or later, depending on the system conditions. Progress curves and phase plots were plotted to understand the steady state behaviour of the metabolites involved. A comparative analysis between experimental and simulated data show fair agreement thus validating the usefulness and applicability of the model.

  4. Cancer metabolism meets systems biology: Pyruvate kinase isoform PKM2 is a metabolic master regulator

    Directory of Open Access Journals (Sweden)

    Fabian V Filipp

    2013-01-01

    Full Text Available Pyruvate kinase activity is controlled by a tightly woven regulatory network. The oncofetal isoform of pyruvate kinase (PKM2 is a master regulator of cancer metabolism. PKM2 engages in parallel, feed-forward, positive and negative feedback control contributing to cancer progression. Besides its metabolic role, non-metabolic functions of PKM2 as protein kinase and transcriptional coactivator for c-MYC and hypoxia-inducible factor 1-alpha are essential for epidermal growth factor receptor activation-induced tumorigenesis. These biochemical activities are controlled by a shift in the oligomeric state of PKM2 that includes acetylation, oxidation, phosphorylation, prolyl hydroxylation and sumoylation. Metabolically active PKM2 tetramer is allosterically regulated and responds to nutritional and stress signals. Metabolically inactive PKM2 dimer is imported into the nucleus and can function as protein kinase stimulating transcription. A systems biology approach to PKM2 at the genome, transcriptome, proteome, metabolome and fluxome level reveals how differences in biomolecular structure translate into a global rewiring of cancer metabolism. Cancer systems biology takes us beyond the Warburg effect, opening unprecedented therapeutic opportunities.

  5. Pyruvate oxidase influences the sugar utilization pattern and capsule production in Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Sandra M Carvalho

    Full Text Available Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence, oxidative stress survival and death in stationary phase. Under semi-aerobic conditions, transcriptomic and metabolite profiling analysis of a spxB mutant grown on glucose showed minor changes compared to the wild type, apart from the significant induction of two operons involved in carbohydrate uptake and processing. This induction leads to a change in the sugar utilization capabilities of the bacterium, as indicated by the analysis of the growth profiles of the D39 parent and spxB mutant on alternative carbohydrates. Metabolic analysis and growth experiments showed that inactivation of SpxB has no effect on the glucose fermentation pattern, except under aerobic conditions. More importantly, we show that mutation of spxB results in the production of increased amounts of capsule, the major virulence factor of S. pneumoniae. Part of this increase can be attributed to induction of capsule operon (cps transcription. Therefore, we propose that S. pneumoniae utilizes pyruvate oxidase as an indirect sensor of the oxygenation of the environment, resulting in the adaption of its nutritional capability and the amount of capsule to survive in the host.

  6. Pyruvate oxidase influences the sugar utilization pattern and capsule production in Streptococcus pneumoniae.

    Science.gov (United States)

    Carvalho, Sandra M; Farshchi Andisi, Vahid; Gradstedt, Henrik; Neef, Jolanda; Kuipers, Oscar P; Neves, Ana R; Bijlsma, Jetta J E

    2013-01-01

    Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence, oxidative stress survival and death in stationary phase. Under semi-aerobic conditions, transcriptomic and metabolite profiling analysis of a spxB mutant grown on glucose showed minor changes compared to the wild type, apart from the significant induction of two operons involved in carbohydrate uptake and processing. This induction leads to a change in the sugar utilization capabilities of the bacterium, as indicated by the analysis of the growth profiles of the D39 parent and spxB mutant on alternative carbohydrates. Metabolic analysis and growth experiments showed that inactivation of SpxB has no effect on the glucose fermentation pattern, except under aerobic conditions. More importantly, we show that mutation of spxB results in the production of increased amounts of capsule, the major virulence factor of S. pneumoniae. Part of this increase can be attributed to induction of capsule operon (cps) transcription. Therefore, we propose that S. pneumoniae utilizes pyruvate oxidase as an indirect sensor of the oxygenation of the environment, resulting in the adaption of its nutritional capability and the amount of capsule to survive in the host.

  7. Erk regulation of pyruvate dehydrogenase flux through PDK4 modulates cell proliferation

    Science.gov (United States)

    Grassian, Alexandra R.; Metallo, Christian M.; Coloff, Jonathan L.; Stephanopoulos, Gregory; Brugge, Joan S.

    2011-01-01

    Loss of extracellular matrix (ECM) attachment leads to metabolic impairments that limit cellular energy production. Characterization of the metabolic alterations induced by ECM detachment revealed a dramatic decrease in uptake of glucose, glutamine, and pyruvate, and a consequent decrease in flux through glycolysis, the pentose phosphate pathway, and the tricarboxylic acid (TCA) cycle. However, flux through pyruvate dehydrogenase (PDH) is disproportionally decreased, concomitant with increased expression of the PDH inhibitory kinase, PDH kinase 4 (PDK4), and increased carbon secretion. Overexpression of ErbB2 maintains PDH flux by suppressing PDK4 expression in an Erk-dependent manner, and Erk signaling also regulates PDH flux in ECM-attached cells. Additionally, epidermal growth factor (EGF), a potent inducer of Erk, positively regulates PDH flux through decreased PDK4 expression. Furthermore, overexpression of PDK4 in ECM-detached cells suppresses the ErbB2-mediated rescue of ATP levels, and in attached cells, PDK4 overexpression decreases PDH flux, de novo lipogenesis, and cell proliferation. Mining of microarray data from human tumor data sets revealed that PDK4 mRNA is commonly down-regulated in tumors compared with their tissues of origin. These results identify a novel mechanism by which ECM attachment, growth factors, and oncogenes modulate the metabolic fate of glucose by controlling PDK4 expression and PDH flux to influence proliferation. PMID:21852536

  8. Src drives the Warburg effect and therapy resistance by inactivating pyruvate dehydrogenase through tyrosine-289 phosphorylation

    Science.gov (United States)

    Shenoy, Anitha K.; Lim, Sangbin; Zhang, Ying; Charles, Steve; Tarrash, Miriam; Fu, Xueqi; Kamarajugadda, Sushama; Trevino, Jose G.; Tan, Ming; Lu, Jianrong

    2016-01-01

    The Warburg effect, which reflects cancer cells' preference for aerobic glycolysis over glucose oxidation, contributes to tumor growth, progression and therapy resistance. The restraint on pyruvate flux into mitochondrial oxidative metabolism in cancer cells is in part attributed to the inhibition of pyruvate dehydrogenase (PDH) complex. Src is a prominent oncogenic non-receptor tyrosine kinase that promotes cancer cell proliferation, invasion, metastasis and resistance to conventional and targeted therapies. However, the potential role of Src in tumor metabolism remained unclear. Here we report that activation of Src attenuated PDH activity and generation of reactive oxygen species (ROS). Conversely, Src inhibitors activated PDH and increased cellular ROS levels. Src inactivated PDH through direct phosphorylation of tyrosine-289 of PDH E1α subunit (PDHA1). Indeed, Src was the main kinase responsible for PDHA1 tyrosine phosphorylation in cancer cells. Expression of a tyrosine-289 non-phosphorable PDHA1 mutant in Src-hyperactivated cancer cells restored PDH activity, increased mitochondrial respiration and oxidative stress, decreased experimental metastasis, and sensitized cancer cells to pro-oxidant treatment. The results suggest that Src contributes to the Warburg phenotype by inactivating PDH through tyrosine phosphorylation, and the metabolic effect of Src is essential for Src-driven malignancy and therapy resistance. Combination therapies consisting of both Src inhibitors and pro-oxidants may improve anticancer efficacy. PMID:26848621

  9. Modulation of Malaria Phenotypes by Pyruvate Kinase (PKLR Variants in a Thai Population.

    Directory of Open Access Journals (Sweden)

    Rebekah van Bruggen

    Full Text Available Pyruvate kinase (PKLR is a critical erythrocyte enzyme that is required for glycolysis and production of ATP. We have shown that Pklr deficiency in mice reduces the severity (reduced parasitemia, increased survival of blood stage malaria induced by infection with Plasmodium chabaudi AS. Likewise, studies in human erythrocytes infected ex vivo with P. falciparum show that presence of host PK-deficiency alleles reduces infection phenotypes. We have characterized the genetic diversity of the PKLR gene, including haplotype structure and presence of rare coding variants in two populations from malaria endemic areas of Thailand and Senegal. We investigated the effect of PKLR genotypes on rich longitudinal datasets including haematological and malaria-associated phenotypes. A coding and possibly damaging variant (R41Q was identified in the Thai population with a minor allele frequency of ~4.7%. Arginine 41 (R41 is highly conserved in the pyruvate kinase family and its substitution to Glutamine (R41Q affects protein stability. Heterozygosity for R41Q is shown to be associated with a significant reduction in the number of attacks with Plasmodium falciparum, while correlating with an increased number of Plasmodium vivax infections. These results strongly suggest that PKLR protein variants may affect the frequency, and the intensity of malaria episodes induced by different Plasmodium parasites in humans living in areas of endemic malaria.

  10. Pyruvate carboxylase is critical for non–small-cell lung cancer proliferation

    Science.gov (United States)

    Sellers, Katherine; Fox, Matthew P.; Bousamra, Michael; Slone, Stephen P.; Higashi, Richard M.; Miller, Donald M.; Wang, Yali; Yan, Jun; Yuneva, Mariia O.; Deshpande, Rahul; Lane, Andrew N.; Fan, Teresa W.-M.

    2015-01-01

    Anabolic biosynthesis requires precursors supplied by the Krebs cycle, which in turn requires anaplerosis to replenish precursor intermediates. The major anaplerotic sources are pyruvate and glutamine, which require the activity of pyruvate carboxylase (PC) and glutaminase 1 (GLS1), respectively. Due to their rapid proliferation, cancer cells have increased anabolic and energy demands; however, different cancer cell types exhibit differential requirements for PC- and GLS-mediated pathways for anaplerosis and cell proliferation. Here, we infused patients with early-stage non–small-cell lung cancer (NSCLC) with uniformly 13C-labeled glucose before tissue resection and determined that the cancerous tissues in these patients had enhanced PC activity. Freshly resected paired lung tissue slices cultured in 13C6-glucose or 13C5,15N2-glutamine tracers confirmed selective activation of PC over GLS in NSCLC. Compared with noncancerous tissues, PC expression was greatly enhanced in cancerous tissues, whereas GLS1 expression showed no trend. Moreover, immunohistochemical analysis of paired lung tissues showed PC overexpression in cancer cells rather than in stromal cells of tumor tissues. PC knockdown induced multinucleation, decreased cell proliferation and colony formation in human NSCLC cells, and reduced tumor growth in a mouse xenograft model. Growth inhibition was accompanied by perturbed Krebs cycle activity, inhibition of lipid and nucleotide biosynthesis, and altered glutathione homeostasis. These findings indicate that PC-mediated anaplerosis in early-stage NSCLC is required for tumor survival and proliferation. PMID:25607840

  11. Methylobacterium sp. isolated from a Finnish paper machine produces highly pyruvated galactan exopolysaccharide.

    Science.gov (United States)

    Verhoef, René; de Waard, Pieter; Schols, Henk A; Siika-aho, Matti; Voragen, Alphons G J

    2003-09-01

    The slime-forming bacterium Methylobacterium sp. was isolated from a Finnish paper machine and its exopolysaccharide (EPS) was produced on laboratory scale. Sugar compositional analysis revealed a 100% galactan (EPS). However, FT-IR showed a very strong peak at 1611 cm(-1) showing the presence of pyruvate. Analysis of the pyruvate content revealed that, based on the sugar composition, the EPS consists of a trisaccharide repeating unit consisting of D-galactopyranose and [4,6-O-(1-carboxyethylidene)]-D-galactopyranose with a molar ratio of 1:2, respectively. Both linkage analysis and 2D homo- and heteronuclear 1H and 13C NMR spectroscopy revealed the following repeating unit: -->3)-[4,6-O-(1-carboxyethylidene)]-alpha-D-Galp-(1-->3)[4,6-O-(1-carboxyethylidene)]-alpha-D-Galp-(1-->3)-alpha-D-Galp-(1-->. By enrichment cultures from various ground and compost heap samples a polysaccharide-degrading culture was obtained that produced an endo acting enzyme able to degrade the EPS described. The enzyme hydrolysed the EPS to a large extent, releasing oligomers that mainly consisted out of two repeating units.

  12. Liquid-liquid extraction equilibrium for pyruvic acid recovery: experimental data and modeling

    Directory of Open Access Journals (Sweden)

    Dharm Pal

    Full Text Available ABSTRACT Physical extraction studies of pyruvic acid from dilute aqueous solutions (0.025 kmol·m-3 to 0.200 kmol·m-3 using several pure solvents (tri-n-butylphosphate (TBP, 1-decanol, 1-octanol, toluene, Methyl-isobutylketone (MIBK, and n-heptane and their binary mixtures are reported in this work. All the batch extraction experiments were carried out at isothermal conditions (T=303±1K and the results are reported in terms of distribution coefficient (K D. The results obtained by the equilibrium studies of the different extraction system were correlated with solvatochromic parameters of the solvents. A linear solvation energy relationship (LSER model was applied to interpret the extraction equilibrium which specifically considers physical interactions. The values of the LSER model parameters for the extraction system were optimized by regression technique and the model equations have been proposed. Experimental and model values were in good agreement (RMSD < 0.1.Reported outcomes are useful in the selection of a suitable extraction system and understanding the extraction mechanism for the separation of pyruvic acid from dilute aqueous solutions.

  13. Heavy-atom isotope effects on binding of reactants to lactate dehydrogenase and pyruvate kinase

    International Nuclear Information System (INIS)

    Gawlita, E.

    1993-04-01

    18 O and 13 C kinetic isotope effects have been measured on the reaction of pyruvate kinase with phospho-enol-pyruvate and ADP using a remote label technique. The magnitude of both investigated isotope effects showed a dependence on the concentration of ADP. However, while the carbon effect was simply 'washed out' to unity at high ATP concentration, the oxygen effect becomes inverse and reached 0.9928 at the highest used concentration of ADP. Such a result testifies that the assumption of the negligible effect of isotopic substitution on enzyme-substrate associations remains correct only for carbon effects. An equilibrium 18 O isotope effect on association of oxalate with lactate dehydrogenase in the presence of NADHP has been evaluated by both experimental and theoretical means. Experimental methods, which involved equilibrium dialysis and gas chromatographic/mass spectrometric measurement of isotopic ration, yielded an inverse value of 0.9840. Semiempirical methods involved vibrational analysis of oxalate in two different environments. The comparison of calculated values with the experimentally determined isotope effect indicated that the AM 1 Hamiltonian proved superior to its PM 3 counterpart in this modelling. 160 refs, 8 figs, 18 tabs

  14. Ketogenic diet in pyruvate dehydrogenase complex deficiency: short- and long-term outcomes.

    Science.gov (United States)

    Sofou, Kalliopi; Dahlin, Maria; Hallböök, Tove; Lindefeldt, Marie; Viggedal, Gerd; Darin, Niklas

    2017-03-01

    Our aime was to study the short- and long-term effects of ketogenic diet on the disease course and disease-related outcomes in patients with pyruvate dehydrogenase complex deficiency, the metabolic factors implicated in treatment outcomes, and potential safety and compliance issues. Pediatric patients diagnosed with pyruvate dehydrogenase complex deficiency in Sweden and treated with ketogenic diet were evaluated. Study assessments at specific time points included developmental and neurocognitive testing, patient log books, and investigator and parental questionnaires. A systematic literature review was also performed. Nineteen patients were assessed, the majority having prenatal disease onset. Patients were treated with ketogenic diet for a median of 2.9 years. All patients alive at the time of data registration at a median age of 6 years. The treatment had a positive effect mainly in the areas of epilepsy, ataxia, sleep disturbance, speech/language development, social functioning, and frequency of hospitalizations. It was also safe-except in one patient who discontinued because of acute pancreatitis. The median plasma concentration of ketone bodies (3-hydroxybutyric acid) was 3.3 mmol/l. Poor dietary compliance was associated with relapsing ataxia and stagnation of motor and neurocognitive development. Results of neurocognitive testing are reported for 12 of 19 patients. Ketogenic diet was an effective and safe treatment for the majority of patients. Treatment effect was mainly determined by disease phenotype and attainment and maintenance of ketosis.

  15. Pyruvate Decarboxylase Provides Growing Pollen Tubes with a Competitive Advantage in PetuniaW⃞

    Science.gov (United States)

    Gass, Nathalie; Glagotskaia, Tatiana; Mellema, Stefan; Stuurman, Jeroen; Barone, Mario; Mandel, Therese; Roessner-Tunali, Ute; Kuhlemeier, Cris

    2005-01-01

    Rapid pollen tube growth places unique demands on energy production and biosynthetic capacity. The aim of this work is to understand how primary metabolism meets the demands of such rapid growth. Aerobically grown pollen produce ethanol in large quantities. The ethanolic fermentation pathway consists of two committed enzymes: pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH). Because adh mutations do not affect male gametophyte function, the obvious question is why pollen synthesize an abundant enzyme if they could do just as well without. Using transposon tagging in Petunia hybrida, we isolated a null mutant in pollen-specific Pdc2. Growth of the mutant pollen tubes through the style is reduced, and the mutant allele shows reduced transmission through the male, when in competition with wild-type pollen. We propose that not ADH but rather PDC is the critical enzyme in a novel, pollen-specific pathway. This pathway serves to bypass pyruvate dehydrogenase enzymes and thereby maintain biosynthetic capacity and energy production under the unique conditions prevailing during pollen–pistil interaction. PMID:15994907

  16. Pyruvate decarboxylase provides growing pollen tubes with a competitive advantage in petunia.

    Science.gov (United States)

    Gass, Nathalie; Glagotskaia, Tatiana; Mellema, Stefan; Stuurman, Jeroen; Barone, Mario; Mandel, Therese; Roessner-Tunali, Ute; Kuhlemeier, Cris

    2005-08-01

    Rapid pollen tube growth places unique demands on energy production and biosynthetic capacity. The aim of this work is to understand how primary metabolism meets the demands of such rapid growth. Aerobically grown pollen produce ethanol in large quantities. The ethanolic fermentation pathway consists of two committed enzymes: pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH). Because adh mutations do not affect male gametophyte function, the obvious question is why pollen synthesize an abundant enzyme if they could do just as well without. Using transposon tagging in Petunia hybrida, we isolated a null mutant in pollen-specific Pdc2. Growth of the mutant pollen tubes through the style is reduced, and the mutant allele shows reduced transmission through the male, when in competition with wild-type pollen. We propose that not ADH but rather PDC is the critical enzyme in a novel, pollen-specific pathway. This pathway serves to bypass pyruvate dehydrogenase enzymes and thereby maintain biosynthetic capacity and energy production under the unique conditions prevailing during pollen-pistil interaction.

  17. Structural intermediates and directionality of the swiveling motion of Pyruvate Phosphate Dikinase

    Science.gov (United States)

    Minges, Alexander; Ciupka, Daniel; Winkler, Christian; Höppner, Astrid; Gohlke, Holger; Groth, Georg

    2017-03-01

    Pyruvate phosphate dikinase (PPDK) is a vital enzyme in cellular energy metabolism catalyzing the ATP- and Pi-dependent formation of phosphoenolpyruvate from pyruvate in C4 -plants, but the reverse reaction forming ATP in bacteria and protozoa. The multi-domain enzyme is considered an efficient molecular machine that performs one of the largest single domain movements in proteins. However, a comprehensive understanding of the proposed swiveling domain motion has been limited by not knowing structural intermediates or molecular dynamics of the catalytic process. Here, we present crystal structures of PPDKs from Flaveria, a model genus for studying the evolution of C4 -enzymes from phylogenetic ancestors. These structures resolve yet unknown conformational intermediates and provide the first detailed view on the large conformational transitions of the protein in the catalytic cycle. Independently performed unrestrained MD simulations and configurational free energy calculations also identified these intermediates. In all, our experimental and computational data reveal strict coupling of the CD swiveling motion to the conformational state of the NBD. Moreover, structural asymmetries and nucleotide binding states in the PPDK dimer support an alternate binding change mechanism for this intriguing bioenergetic enzyme.

  18. Mechanism of Decarboxylation of Pyruvic Acid in the Presence of Hydrogen Peroxide.

    Science.gov (United States)

    Lopalco, Antonio; Dalwadi, Gautam; Niu, Sida; Schowen, Richard L; Douglas, Justin; Stella, Valentino J

    2016-02-01

    The purpose of this work was to probe the rate and mechanism of rapid decarboxylation of pyruvic acid in the presence of hydrogen peroxide (H2O2) to acetic acid and carbon dioxide over the pH range 2-9 at 25 °C, utilizing UV spectrophotometry, high performance liquid chromatography (HPLC), and proton and carbon nuclear magnetic resonance spectrometry ((1)H, (13)C-NMR). Changes in UV absorbance at 220 nm were used to determine the kinetics as the reaction was too fast to follow by HPLC or NMR in much of the pH range. The rate constants for the reaction were determined in the presence of molar excess of H2O2 resulting in pseudo first-order kinetics. No buffer catalysis was observed. The calculated second-order rate constants for the reaction followed a sigmoidal shape with pH-independent regions below pH 3 and above pH 7 but increased between pH 4 and 6. Between pH 4 and 9, the results were in agreement with a change from rate-determining nucleophilic attack of the deprotonated peroxide species, HOO(-), on the α-carbonyl group followed by rapid decarboxylation at pH values below 6 to rate-determining decarboxylation above pH 7. The addition of H2O2 to ethyl pyruvate was also characterized. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  19. Gluconeogenesis in Leishmania mexicana: contribution of glycerol kinase, phosphoenolpyruvate carboxykinase, and pyruvate phosphate dikinase.

    Science.gov (United States)

    Rodriguez-Contreras, Dayana; Hamilton, Nicklas

    2014-11-21

    Gluconeogenesis is an active pathway in Leishmania amastigotes and is essential for their survival within the mammalian cells. However, our knowledge about this pathway in trypanosomatids is very limited. We investigated the role of glycerol kinase (GK), phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate phosphate dikinase (PPDK) in gluconeogenesis by generating the respective Leishmania mexicana Δgk, Δpepck, and Δppdk null mutants. Our results demonstrated that indeed GK, PEPCK, and PPDK are key players in the gluconeogenesis pathway in Leishmania, although stage-specific differences in their contribution to this pathway were found. GK participates in the entry of glycerol in promastigotes and amastigotes; PEPCK participates in the entry of aspartate in promastigotes, and PPDK is involved in the entry of alanine in amastigotes. Furthermore, the majority of alanine enters into the pathway via decarboxylation of pyruvate in promastigotes, whereas pathway redundancy is suggested for the entry of aspartate in amastigotes. Interestingly, we also found that l-lactate, an abundant glucogenic precursor in mammals, was used by Leishmania amastigotes to synthesize mannogen, entering the pathway through PPDK. On the basis of these new results, we propose a revision in the current model of gluconeogenesis in Leishmania, emphasizing the differences between amastigotes and promastigotes. This work underlines the importance of studying the trypanosomatid intracellular life cycle stages to gain a better understanding of the pathologies caused in humans. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. n-Octyl gallate as inhibitor of pyruvate carboxylation and lactate gluconeogenesis.

    Science.gov (United States)

    Eler, Gabrielle Jacklin; Santos, Israel Souza; de Moraes, Amarilis Giaretta; Comar, Jurandir Fernando; Peralta, Rosane Marina; Bracht, Adelar

    2015-04-01

    The alkyl gallates are found in several natural and industrial products. In the latter products, these compounds are added mainly for preventing oxidation. In the present work, the potencies of methyl gallate, n-propyl gallate, n-pentyl gallate, and n-octyl gallate as inhibitors of pyruvate carboxylation and lactate gluconeogenesis were evaluated. Experiments were done with isolated mitochondria and the isolated perfused rat liver. The potency of the gallic acid esters as inhibitors of pyruvate carboxylation in isolated mitochondria obeyed the following decreasing sequence: n-octyl gallate > n-pentyl gallate > n-propyl gallate > methyl gallate. A similar sequence of decreasing potency for lactate gluconeogenesis inhibition in the perfused liver was found in terms of the portal venous concentration. Both actions correlate with the lipophilicity of the compounds. The effects are harmful at high concentrations. At appropriate concentrations, however, octyl gallate should act therapeutically because its inhibitory action on gluconeogenesis will contribute further to its proposed antihyperglycemic effects. © 2014 Wiley Periodicals, Inc.

  1. Enzymatic and mechanistic studies on the formation of N-phenylglycolohydroxamic acid from nitrosobenzene and pyruvate in spinach leaf homogenate.

    Science.gov (United States)

    Tatsunami, Ryosuke; Yoshioka, Tadao

    2006-01-25

    The biotransformation mechanism of an unknown metabolite formed enzymatically from nitrosobenzene (NOB) and pyruvate in spinach (Spinacea oleracea L.) was investigated using spinach leaf homogenate. The unknown metabolite was identified as N-phenylglycolohydroxamic acid (PGA). The activity of PGA formation was decreased by l-alanine, increased by l-serine, and completely inhibited by aminooxyacetic acid, an inhibitor of transaminases. These results indicate that the transaminase participates in PGA formation. Indeed, hydroxypyruvate and alanine were produced in the transamination between pyruvate and serine. Hydroxypyruvate served as a direct-acting glycoloyl donor for PGA formation. A good correlation between the activities of the 200 g supernatant of spinach homogenate and commercial yeast transketolase for PGA formation from several glycoloyl donors was obtained. These results suggest the following mechanism for PGA formation from NOB and pyruvate: transamination of l-serine into hydroxypyruvate, which serves as a glycoloyl donor to NOB.

  2. Brain ischemia and infarction positively visualized by pyruvate-1-11C using positron-emission tomography

    International Nuclear Information System (INIS)

    Hara, Toshihiko; Iio, Masaaki; Yokoi, Fuji

    1986-01-01

    We describe positron-emission tomography (PET) scintigraphic findings obtained using pyruvate-1- 11 C in eight patients with cerebral ischemic hypoxia or infarction. The extraction of 11 C by brain tissue from blood after an i.v. injection of 11 C-pyruvate was very rapid, being almost complete after a single circulatory passage. Most ischemic lesions were found to be more or less deficient with regard to 11 C-extraction capacity. With time, however, the ratio of 11 C in ischemic tissue to that in normal tissue was inverted, and the ischemic lesion appeared as a ''hot'' area in the scintigram. Very old infarcts did not exhibit this phenomenon. These observations indicate the usefulness of an 11 C-pyruvate PET scan for the diagnosis of therapeutically restorable brain damage. (orig.)

  3. Effect of gamma radiation on the concentration of pyruvate and lactate in erythrocytes of healthy men after submaximal physical exercise

    International Nuclear Information System (INIS)

    Zagorski, T.; Dudek, I.; Berkan, L.; Chmielewski, H.; Kedziora, J.

    1993-01-01

    The aim of this work was to study the effect of gamma radiation and submaximal physical exercise on the concentration of final products of anaerobic glycolytic pathway in erythrocytes of healthy men. Twenty one men aged 20-22 were examined. They underwent physical exercise at doses of 2 w/kg body weight for 15 min. Erythrocytes were taken in the rest and after physical exercise and were exposed to gamma radiation (500 Gy doses) from 60 Co source. The concentration of pyruvate was estimated by Fermognost tests and the concentration of lactate by Boehringer Mannheim tests. The submaximal physical exercise was found to cause a significantly increased concentration of pyruvate and lactate in the non-radiated and irradiated erythrocytes. Gamma radiation at 500 Gy dose was found to increase concentration of pyruvate in erythrocytes (in the rest and after physical exercise) with simultaneous decrease of lactate concentration. (author). 17 refs, 1 tab

  4. Identification of cysteine as the reactive group in pyruvate kinase alkylated by 5-chloro-4-oxopentanoic acid.

    Science.gov (United States)

    Chalkley, R A; Bloxham, D P

    1976-11-01

    4-Hydroxypentanoic acid alanine thioether was synthesized and characterized by n.m.r. spectroscopy. This derivative corresponded to the modified amino acid obtained by allowing 5-chloro-4-oxo[3,5-3H]pentanoic acid to react with rabbit muscle pyruvate kinase. Performic acid oxidation of 4-oxo[3,5-3H]pentanoic acid alanine thioether in pyruvate kinase gave [3H]succinate (67%) and [3H]carboxymethylcysteine (33%) as expected. Evidence is presented to show that NaBH4 reduction followed by periodate oxidation and analysis of radioactive formaldehyde production may provide a convenient method for distinguishing between thiol and amino alkylation by halogenomethyl ketone compounds. Peptide 'mapping' confirms that the modification by 5-chloro-4-oxopentanoic acid occurs primarily at one region of pyruvate kinase.

  5. Anatomia do fígado de fetos de Guinea pig em final de gestação (Cavia porcellus [Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Mariangela Toledo Barbino

    2011-08-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2011v24n3p97 Desenvolveu-se este trabalho com o objetivo de descrever a anatomia do fígado de fetos de Guinea pig (Cavia porcellus [Linnaeus, 1758] em final de gestação e obter caracterizações anatômicas que possam fundamentar e auxiliar na compreensão da fisiologia da circulação fetal. Coletou-se os fetos de 3 fêmeas em final de gestação, os quais foram dissecados e retirado o fígado. Estes foram analisados, descritos e fotodocumentados macroscopicamente, por microscopia de luz em coloração HE e por microscopia eletrônica de varredura. O fígado dos fetos apresenta coloração castanho avermelhada e sua divisão em lobos é nitidamente observada, assim como a presença da vesícula biliar.  O fígado divide-se em lobo lateral esquerdo, lobo medial esquerdo, lobo lateral direito, lobo medial direito, lobo quadrado e lobo caudado com processos papilar e caudado Através da microscopia de luz, observa-se o tecido intensamente vascularizado sendo que, a porção esquerda do fígado recebe o sangue oriundo da placenta pela veia umbilical, e a porção direita é irrigada pela veia porta. Através desses resultados pode-se concluir que os fetos de Guinea pig possuem estruturas semelhantes anatomicamente aos de outras espécies de mamíferos.

  6. Intake, selection, digesta retention, digestion and gut fill of two coprophageous species, rabbits (Oryctolagus cuniculus) and guinea pigs (Cavia porcellus), on a hay-only diet.

    Science.gov (United States)

    Franz, R; Kreuzer, M; Hummel, J; Hatt, J-M; Clauss, M

    2011-10-01

    A colonic separation mechanism (CSM) is the prerequisite for the digestive strategy of coprophagy. Two different CSM are known in small herbivores, the 'wash-back' CSM of lagomorphs and the 'mucous-trap' CSM of rodents. Differences between these groups in their digestive pattern when fed exclusively hay were investigated in six rabbits (Oryctolagus cuniculus) and six guinea pigs (Cavia porcellus). Intake, digestibility (by total faecal collection), solute and particle mean retention times (MRT, using Co-EDTA and Cr-mordanted fibres) were measured. Rabbits selected less fibrous parts of the hay than guinea pigs, leaving orts with higher content of neutral detergent fibre [NDF; 721 ± 21 vs. 642 ± 31 g/kg dry matter (DM) in guinea pigs]. They also expressed a lower NDF digestibility (0.44 ± 0.10 vs. 0.55 ± 0.05 of total), a similar particle MRT (15 ± 3 vs. 18 ± 6 h), a longer solute MRT (51 ± 9 vs. 16 ± 4 h), and a lower calculated dry matter gut fill (19.6 ± 4.7 vs. 29.7 ± 4.1 g DM/kg body mass) than guinea pigs (p bacterial matter from the colonic digesta plug than the 'mucous-trap' CSM found in the guinea pigs. Related to metabolic body mass, rabbits therefore need a less capacious colon for their CSM where a more efficient bacteria wash-out is reflected in the lower fibre digestibility. A lighter digestive tract could contribute to a peculiarity of lagomorphs: their ability to run faster than other similar-sized mammals. © 2010 Blackwell Verlag GmbH.

  7. Absence of CD59 in Guinea Pigs: Analysis of theCavia porcellusGenome Suggests the Evolution of aCD59Pseudogene.

    Science.gov (United States)

    Boshra, Hani; Zelek, Wioleta M; Hughes, Timothy R; Rodriguez de Cordoba, Santiago; Morgan, B Paul

    2018-01-01

    CD59 is a membrane-bound regulatory protein that inhibits the assembly of the terminal membrane attack complex (C5b-9) of complement. From its original discovery in humans almost 30 years ago, CD59 has been characterized in a variety of species, from primates to early vertebrates, such as teleost fish. CD59 is ubiquitous in mammals; however, we have described circumstantial evidence suggesting that guinea pigs ( Cavia porcellus ) lack CD59, at least on erythrocytes. In this study, we have used a combination of phylogenetic analyses with syntenic alignment of mammalian CD59 genes to identify the only span of genomic DNA in C. porcellus that is homologous to a portion of mammalian CD59 and show that this segment of DNA is not transcribed. We describe a pseudogene sharing homology to exons 2 through 5 of human CD59 present in the C. porcellus genome. This pseudogene was flanked by C. porcellus homologs of two genes, FBXO3 and ORF91 , a relationship and orientation that were consistent with other known mammalian CD59 genes. Analysis using RNA sequencing confirmed that this segment of chromosomal DNA was not transcribed. We conclude that guinea pigs lack an intact gene encoding CD59; to our knowledge, this is the first report of a mammalian species that does not express a functional CD59. The pseudogene we describe is likely the product of a genomic deletion event during its evolutionary divergence from other members of the rodent order. Copyright © 2017 by The American Association of Immunologists, Inc.

  8. Differences between magnesium-activated and manganese-activated pyruvate kinase from the muscle of Concholepas concholepas.

    Science.gov (United States)

    González, R; Carvajal, N; Morán, A

    1984-01-01

    In contrast to the Mg2+-activated enzyme, in the presence of Mn2+ pyruvate kinase exhibits hyperbolic kinetics with respect to the substrate phosphoenolpyruvate and is insensitive to fructose 1,6-biphosphate, phenylalanine and alanine. However, with both metal activated species inhibition by excess ADP is observed. In contrast with Mg2+, which affords significant protection against inactivation caused by 5,5'-dithiobis (2-nitrobenzoic acid), the rate of inactivation by this reagent is increased in the presence of Mn2+. Differences in conformational changes induced by combination of pyruvate kinase with Mg2+ or Mn2+ were indicated by u.v. difference spectra.

  9. Saturation-recovery metabolic‐exchange rate imaging with hyperpolarized [1‐13C] pyruvate using spectral‐spatial excitation

    DEFF Research Database (Denmark)

    Schulte, Rolf F.; Sperl, Jonathan I.; Weidl, Eliane

    2013-01-01

    ‐recovery” scheme with the detected signal content being determined by forward conversion of the available pyruvate. In case of repetitive excitations, the polarization is preserved using smaller flip angles for pyruvate. Metabolic exchange rates are determined spatially resolved from the metabolite images using...... a simplified two‐site exchange model. This novel contrast is an important step toward more quantitative metabolic imaging. Goal of this work was to derive, analyze, and implement this “saturation‐recovery metabolic exchange rate imaging” and demonstrate its capabilities in four rats bearing subcutaneous tumors...

  10. Cerebrospinal fluid acid-base status and lactate and pyruvate concentrations after convulsions of varied duration and aetiology in children.

    Science.gov (United States)

    Simpson, H; Habel, A H; George, E L

    1977-01-01

    Twenty-two infants and children were studied after convulsions of varied cause and duration. Arterial and CSF acid-base variables, lactate and pyruvate concentrations, and lactate/pyruvate ratios were measured between 3 and 18 hours after convulsive episodes. Biochemical signs of cerebral hypoxia were found in 7 patients with prolonged (greater than 30 minutes) or recurrent short convulsions. These signs were absent in patients with single short convulsions. These findings indicate that cerebral hypoxia and possible brain damage is a hazard of prolonged or rapidly recurring short convulsions. PMID:23078

  11. Transmissão do Trypanosoma cruzi em três gerações de Cavia porcellus sem a participação de triatomíneos

    Directory of Open Access Journals (Sweden)

    Ítalo A. Sherlock

    1976-02-01

    Full Text Available Foi verificada a transmissão sucessiva do T. cruzi em três gerações da cobaia Cavia porcellus sem a participação de triatomíneos. Embora não fosse determinado qual das vias, se placentária, leite, excreções ou contágio direto pelo qual o protozoário foi transmitido para os descendentes, chama-se atenção para a importância da manutenção de reservatórios da Doença de Chagas, mesmo na ausência de vetores invertebrados.The sucessive transmission of Trypanosoma cruzi among three generations of the guinea pig Cavia porcellus without the participation of triatomine bugs is verified. Although the mode of transmission, such as congenital, infected milk or other excretion or direct contagion was not defined, this maybe of importance in natural maintenance of reservoirs of T. cruzi without the invertebrate vectors.

  12. Ethyl pyruvate inhibits proliferation and induces apoptosis of hepatocellular carcinoma via regulation of the HMGB1–RAGE and AKT pathways

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Ping; Dai, Weiqi; Wang, Fan; Lu, Jie; Shen, Miao; Chen, Kan; Li, Jingjing; Zhang, Yan; Wang, Chengfen; Yang, Jing; Zhu, Rong; Zhang, Huawei; Zheng, Yuanyuan; Guo, Chuan-Yong, E-mail: guochuanyong@hotmail.com; Xu, Ling, E-mail: xuling606@sina.com

    2014-01-24

    Highlights: • Ethyl pyruvate inhibits liver cancer. • Promotes apoptosis. • Decreased the expression of HMGB1, p-Akt. - Abstract: Ethyl pyruvate (EP) was recently identified as a stable lipophilic derivative of pyruvic acid with significant antineoplastic activities. The high mobility group box-B1 (HMGB1)–receptor for advanced glycation end-products (RAGE) and the protein kinase B (Akt) pathways play a crucial role in tumorigenesis and development of many malignant tumors. We tried to observe the effects of ethyl pyruvate on liver cancer growth and explored its effects in hepatocellular carcinoma model. In this study, three hepatocellular carcinoma cell lines were treated with ethyl pyruvate. An MTT colorimetric assay was used to assess the effects of EP on cell proliferation. Flow cytometry and TUNEL assays were used to analyze apoptosis. Real-time PCR, Western blotting and immunofluorescence demonstrated ethyl pyruvate reduced the HMGB1–RAGE and AKT pathways. The results of hepatoma orthotopic tumor model verified the antitumor effects of ethyl pyruvate in vivo. EP could induce apoptosis and slow the growth of liver cancer. Moreover, EP decreased the expression of HMGB1, RAGE, p-AKT and matrix metallopeptidase-9 (MMP9) and increased the Bax/Bcl-2 ratio. In conclusion, this study demonstrates that ethyl pyruvate induces apoptosis and cell-cycle arrest in G phase in hepatocellular carcinoma cells, plays a critical role in the treatment of cancer.

  13. Effects of adrenergic agents on intracellular ca(2+) homeostasis and metabolism of glucose in astrocytes with an emphasis on pyruvate carboxylation, oxidative decarboxylation and recycling

    DEFF Research Database (Denmark)

    Obel, Linea Lykke Frimodt; Andersen, Karen M H; Bak, Lasse Kristoffer

    2012-01-01

    and oxidative decarboxylation in astrocytic glucose metabolism. Importantly, pyruvate carboxylation was best visualized at 10 min of incubation. The abundance and pattern of labeling in lactate and alanine indicated not only an extensive activity of malic enzyme (initial step for pyruvate recycling) but also...

  14. Pyruvate induces transient tumor hypoxia by enhancing mitochondrial oxygen consumption and potentiates the anti-tumor effect of a hypoxia-activated prodrug TH-302.

    Directory of Open Access Journals (Sweden)

    Yoichi Takakusagi

    Full Text Available BACKGROUND: TH-302 is a hypoxia-activated prodrug (HAP of bromo isophosphoramide mustard that is selectively activated within hypoxic regions in solid tumors. Our recent study showed that intravenously administered bolus pyruvate can transiently induce hypoxia in tumors. We investigated the mechanism underlying the induction of transient hypoxia and the combination use of pyruvate to potentiate the anti-tumor effect of TH-302. METHODOLOGY/RESULTS: The hypoxia-dependent cytotoxicity of TH-302 was evaluated by a viability assay in murine SCCVII and human HT29 cells. Modulation in cellular oxygen consumption and in vivo tumor oxygenation by the pyruvate treatment was monitored by extracellular flux analysis and electron paramagnetic resonance (EPR oxygen imaging, respectively. The enhancement of the anti-tumor effect of TH-302 by pyruvate treatment was evaluated by monitoring the growth suppression of the tumor xenografts inoculated subcutaneously in mice. TH-302 preferentially inhibited the growth of both SCCVII and HT29 cells under hypoxic conditions (0.1% O2, with minimal effect under aerobic conditions (21% O2. Basal oxygen consumption rates increased after the pyruvate treatment in SCCVII cells in a concentration-dependent manner, suggesting that pyruvate enhances the mitochondrial respiration to consume excess cellular oxygen. In vivo EPR oxygen imaging showed that the intravenous administration of pyruvate globally induced the transient hypoxia 30 min after the injection in SCCVII and HT29 tumors at the size of 500-1500 mm(3. Pretreatment of SCCVII tumor bearing mice with pyruvate 30 min prior to TH-302 administration, initiated with small tumors (∼ 550 mm(3, significantly delayed tumor growth. CONCLUSIONS/SIGNIFICANCE: Our in vitro and in vivo studies showed that pyruvate induces transient hypoxia by enhancing mitochondrial oxygen consumption in tumor cells. TH-302 therapy can be potentiated by pyruvate pretreatment if started at the

  15. Sources and sinks of formic, acetic, and pyruvic acids over central Amazonia. II - Wet season

    Science.gov (United States)

    Talbot, R. W.; Andreae, M. O.; Berresheim, H.; Jacob, D. J.; Beecher, K. M.

    1990-01-01

    Potential sources and sinks of formic, acetic, and pyruvic acids over the Amazon forest were investigated using a photochemical model and data collected on gas phase concentrations of these acids in the forest canopy, boundary layer, and free troposphere over the central Amazon Basin during the 1987 wet season. It was found that the atmospheric reactions previously suggested in the literature as sources of carboxylic acids (i.e., the gas phase decomposition of isoprene, the reaction between CH3CO3 and a peroxide, and aqueous phase oxidation of CH2O) appear to be too slow to explain the observed concentrations, suggesting that other atmospheric reactions, so far unidentified, could make a major contribution to the carboxylic acid budgets.

  16. Auxins Upregulate Expression of the Indole-3-Pyruvate Decarboxylase Gene in Azospirillum brasilense

    Science.gov (United States)

    Vande Broek, Ann; Lambrecht, Mark; Eggermont, Kristel; Vanderleyden, Jos

    1999-01-01

    Transcription of the Azospirillum brasilense ipdC gene, encoding an indole-3-pyruvate decarboxylase involved in the biosynthesis of indole-3-acetic acid (IAA), is induced by IAA as determined by ipdC-gusA expression studies and Northern analysis. Besides IAA, exogenously added synthetic auxins such as 1-naphthaleneacetic acid, 2,4-dichlorophenoxypropionic acid, and p-chlorophenoxyacetic acid were also found to upregulate ipdC expression. No upregulation was observed with tryptophan, acetic acid, or propionic acid or with the IAA conjugates IAA ethyl ester and IAA-l-phenylalanine, indicating structural specificity is required for ipdC induction. This is the first report describing the induction of a bacterial gene by auxin. PMID:9973364

  17. Loss of succinate dehydrogenase activity results in dependency on pyruvate carboxylation for cellular anabolism

    Science.gov (United States)

    Lussey-Lepoutre, Charlotte; Hollinshead, Kate E. R.; Ludwig, Christian; Menara, Mélanie; Morin, Aurélie; Castro-Vega, Luis-Jaime; Parker, Seth J.; Janin, Maxime; Martinelli, Cosimo; Ottolenghi, Chris; Metallo, Christian; Gimenez-Roqueplo, Anne-Paule; Favier, Judith; Tennant, Daniel A.

    2015-01-01

    The tricarboxylic acid (TCA) cycle is a central metabolic pathway responsible for supplying reducing potential for oxidative phosphorylation and anabolic substrates for cell growth, repair and proliferation. As such it thought to be essential for cell proliferation and tissue homeostasis. However, since the initial report of an inactivating mutation in the TCA cycle enzyme complex, succinate dehydrogenase (SDH) in paraganglioma (PGL), it has become clear that some cells and tissues are not only able to survive with a truncated TCA cycle, but that they are also able of supporting proliferative phenotype observed in tumours. Here, we show that loss of SDH activity leads to changes in the metabolism of non-essential amino acids. In particular, we demonstrate that pyruvate carboxylase is essential to re-supply the depleted pool of aspartate in SDH-deficient cells. Our results demonstrate that the loss of SDH reduces the metabolic plasticity of cells, suggesting vulnerabilities that can be targeted therapeutically. PMID:26522426

  18. The effects of creatine pyruvate and creatine citrate on performance during high intensity exercise

    Directory of Open Access Journals (Sweden)

    Purpura Martin

    2008-02-01

    Full Text Available Abstract Background A double-blind, placebo-controlled, randomized study was performed to evaluate the effect of oral creatine pyruvate (Cr-Pyr and creatine citrate (Cr-Cit supplementation on exercise performance in healthy young athletes. Methods Performance during intermittent handgrip exercise of maximal intensity was evaluated before (pretest and after (posttest 28 days of Cr-Pyr (5 g/d, n = 16, Cr-Cit (5 g/d, n = 16 or placebo (pla, 5 g/d, n = 17 intake. Subjects performed ten 15-sec exercise intervals, each followed by 45 sec rest periods. Results Cr-Pyr (p Conclusion It is concluded that four weeks of Cr-Pyr and Cr-Cit intake significantly improves performance during intermittent handgrip exercise of maximal intensity and that Cr-Pyr might benefit endurance, due to enhanced activity of the aerobic metabolism.

  19. Apparent rate constant mapping using hyperpolarized [1-(13) C]pyruvate

    DEFF Research Database (Denmark)

    Khegai, O.; Schulte, R. F.; Janich, M. A.

    2014-01-01

    frequencies are automatically estimated using a matching pursuit algorithm. Second, a time-discretized formulation of the two-site exchange kinetic model is used to quantify metabolite signal dynamics by two characteristic rate constants in the form of (i) an apparent build-up rate (quantifying the build......) and suppression of high perfusion regions with low conversion (e.g. blood vessels). Apparent build-up rate constant mapping provides a novel quantitative image contrast for the characterization of metabolic activity. Its possible implementation as a quantitative standard will be subject to further studies......-up of downstream metabolites from the pyruvate substrate) and (ii) an effective decay rate (summarizing signal depletion due to repetitive excitation, T1-relaxation and backward conversion). The presented spectral and kinetic quantification were experimentally verified in vitro and in vivo using hyperpolarized [1...

  20. Crystal Structures of Human and Staphylococcus aureus Pyruvate Carboxylase and Molecular Insights into the Carboxyltransfer Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Xiang,S.; Tong, L.

    2008-01-01

    Pyruvate carboxylase (PC) catalyzes the biotin-dependent production of oxaloacetate and has important roles in gluconeogenesis, lipogenesis, insulin secretion and other cellular processes. PC contains the biotin carboxylase (BC), carboxyltransferase (CT) and biotin-carboxyl carrier protein (BCCP) domains. We report here the crystal structures at 2.8-Angstroms resolution of full-length PC from Staphylococcus aureus and the C-terminal region (missing only the BC domain) of human PC. A conserved tetrameric association is observed for both enzymes, and our structural and mutagenesis studies reveal a previously uncharacterized domain, the PC tetramerization (PT) domain, which is important for oligomerization. A BCCP domain is located in the active site of the CT domain, providing the first molecular insights into how biotin participates in the carboxyltransfer reaction. There are dramatic differences in domain positions in the monomer and the organization of the tetramer between these enzymes and the PC from Rhizobium etli.

  1. Further investigation of inhibitors of MRSA pyruvate kinase: Towards the conception of novel antimicrobial agents.

    Science.gov (United States)

    Labrière, Christophe; Gong, Huansheng; Finlay, B Brett; Reiner, Neil E; Young, Robert N

    2017-01-05

    Several novel series of compounds were synthesized and evaluated as inhibitors of methicillin-resistant Staphylococcus aureus (MRSA) pyruvate kinase (PK). PK has been identified as a highly interconnected essential 'hub' protein in MRSA, with structural features distinct from the human homologs which makes it a novel antimicrobial target. Several MRSA PK inhibitors (including the hydrazide 1) were identified using in silico screening combined with enzyme assays and were found to be selective for bacterial enzyme compared to human PK isoforms. Structure-activity relationship (SAR) studies were carried out on the replacement of the hydrazide linker with 3-atoms, 2-atoms and 0-atom linkers and led us to discover more potent compounds with enzyme inhibiting activities in the low nanomolar range and some were found to effectively inhibit bacteria growth in culture with minimum inhibitory concentrations (MIC) as low as 1 μg/mL. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. Detection and formation scenario of citric acid, pyruvic acid, and other possible metabolism precursors in carbonaceous meteorites

    Science.gov (United States)

    Cooper, George; Reed, Chris; Nguyen, Dang; Carter, Malika; Wang, Yi

    2011-01-01

    Carbonaceous meteorites deliver a variety of organic compounds to Earth that may have played a role in the origin and/or evolution of biochemical pathways. Some apparently ancient and critical metabolic processes require several compounds, some of which are relatively labile such as keto acids. Therefore, a prebiotic setting for any such individual process would have required either a continuous distant source for the entire suite of intact precursor molecules and/or an energetic and compact local synthesis, particularly of the more fragile members. To date, compounds such as pyruvic acid, oxaloacetic acid, citric acid, isocitric acid, and α-ketoglutaric acid (all members of the citric acid cycle) have not been identified in extraterrestrial sources or, as a group, as part of a “one pot” suite of compounds synthesized under plausibly prebiotic conditions. We have identified these compounds and others in carbonaceous meteorites and/or as low temperature (laboratory) reaction products of pyruvic acid. In meteorites, we observe many as part of three newly reported classes of compounds: keto acids (pyruvic acid and homologs), hydroxy tricarboxylic acids (citric acid and homologs), and tricarboxylic acids. Laboratory syntheses using 13C-labeled reactants demonstrate that one compound alone, pyruvic acid, can produce several (nonenzymatic) members of the citric acid cycle including oxaloacetic acid. The isotopic composition of some of the meteoritic keto acids points to interstellar or presolar origins, indicating that such compounds might also exist in other planetary systems. PMID:21825143

  3. Brain hypoxanthine concentration correlates to lactate/pyruvate ratio but not intracranial pressure in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, Peter Nissen; Hauerberg, John; Jørgensen, Linda

    2010-01-01

    of hypoxanthine, inosine, and lactate/pyruvate (LP) ratio are increased and correlated in patients with acute liver failure. Furthermore, we expect the purines and L/P ratio to correlate with intracranial pressure (ICP) (positively), and cerebral perfusion pressure (CPP) (negatively)....

  4. Multi-echo balanced steady state imaging of hyperpolarized [1-13C]-pyruvate at 9.4T

    DEFF Research Database (Denmark)

    Mariager, Christian; Riis-Vestergaard, Mette Ji; Qi, Haiyun

    2017-01-01

    Hyperpolarized (HP) [1- 13C]-pyruvate imaging has gained increasing attention, as its ability to monitor metabolic changes in real-time is expected tohave a great clinical impact. In this work we investigate the use of a fast multi-echo balanced steady state free precession (BSSFP) sequence...

  5. Pyruvate: immunonutritional effects on neutrophil intracellular amino or alpha-keto acid profiles and reactive oxygen species production

    NARCIS (Netherlands)

    Mathioudakis, D.; Engel, J.; Welters, I.D.; Dehne, M.G.; Matejec, R.; Harbach, H.; Henrich, M.; Schwandner, T.; Fuchs, M.; Weismuller, K.; Scheffer, G.J.; Muhling, J.

    2011-01-01

    For the first time the immunonutritional role of pyruvate on neutrophils (PMN), free alpha-keto and amino acid profiles, important reactive oxygen species (ROS) produced [superoxide anion (O(2) (-)), hydrogen peroxide (H(2)O(2))] as well as released myeloperoxidase (MPO) acitivity has been

  6. Leigh syndrome associated with a deficiency of the pyruvate dehydrogenase complex: results of treatment with a ketogenic diet

    NARCIS (Netherlands)

    Wijburg, F. A.; Barth, P. G.; Bindoff, L. A.; Birch-Machin, M. A.; van der Blij, J. F.; Ruitenbeek, W.; TURNBULL, D. M.; Schutgens, R. B.

    1992-01-01

    A one-year-old boy suffering from intermittent lactic acidosis, muscular hypotonia, horizontal gaze paralysis and spasticity in both legs had low activity of the pyruvate dehydrogenase complex associated with low amounts of immunoreactive E 1 alpha and E 1 beta. Leigh syndrome was diagnosed on the

  7. Decreased Inflammatory Responses of Human Lung Epithelial Cells after Ethanol Exposure Are Mimicked by Ethyl Pyruvate

    Directory of Open Access Journals (Sweden)

    B. Relja

    2014-01-01

    Full Text Available Background and Purpose. Leukocyte migration into alveolar space plays a critical role in pulmonary inflammation resulting in lung injury. Acute ethanol (EtOH exposure exerts anti-inflammatory effects. The clinical use of EtOH is critical due to its side effects. Here, we compared effects of EtOH and ethyl pyruvate (EtP on neutrophil adhesion and activation of cultured alveolar epithelial cells (A549. Experimental Approach. Time course and dose-dependent release of interleukin- (IL- 6 and IL-8 from A549 were measured after pretreatment of A549 with EtP (2.5–10 mM, sodium pyruvate (NaP, 10 mM, or EtOH (85–170 mM, and subsequent lipopolysaccharide or IL-1beta stimulation. Neutrophil adhesion to pretreated and stimulated A549 monolayers and CD54 surface expression were determined. Key Results. Treating A549 with EtOH or EtP reduced substantially the cytokine-induced release of IL-8 and IL-6. EtOH and EtP (but not NaP reduced the adhesion of neutrophils to monolayers in a dose- and time-dependent fashion. CD54 expression on A549 decreased after EtOH or EtP treatment before IL-1beta stimulation. Conclusions and Implications. EtP reduces secretory and adhesive potential of lung epithelial cells under inflammatory conditions. These findings suggest EtP as a potential treatment alternative that mimics the anti-inflammatory effects of EtOH in early inflammatory response in lungs.

  8. In vitro bioconversion of chitin to pyruvate with thermophilic enzymes.

    Science.gov (United States)

    Honda, Kohsuke; Kimura, Keisuke; Ninh, Pham Huynh; Taniguchi, Hironori; Okano, Kenji; Ohtake, Hisao

    2017-09-01

    Chitin is the second most abundant organic compound on the planet and thus has been regarded as an alternative resource to petroleum feedstocks. One of the key challenges in the biological conversion of biomass-derived polysaccharides, such as cellulose and chitin, is to close the gap between optimum temperatures for enzymatic saccharification and microbial fermentation and to implement them in a single bioreactor. To address this issue, in the present study, we aimed to perform an in vitro, one-pot bioconversion of chitin to pyruvate, which is a precursor of a wide range of useful metabolites. Twelve thermophilic enzymes, including that for NAD + regeneration, were heterologously produced in Escherichia coli and semi-purified by heat treatment of the crude extract of recombinant cells. When the experimentally decided concentrations of enzymes were incubated with 0.5 mg mL -1 colloidal chitin (equivalent to 2.5 mM N-acetylglucosamine unit) and an adequate set of cofactors at 70°C, 0.62 mM pyruvate was produced in 5 h. Despite the use of a cofactor-balanced pathway, determination of the pool sizes of cofactors showed a rapid decrease in ATP concentration, most probably due to the thermally stable ATP-degrading enzyme(s) derived from the host cell. Integration of an additional enzyme set of thermophilic adenylate kinase and polyphosphate kinase led to the deceleration of ATP degradation, and the final product titer was improved to 2.1 mM. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Cerebral Developmental Abnormalities in a Mouse with Systemic Pyruvate Dehydrogenase Deficiency.

    Directory of Open Access Journals (Sweden)

    Lioudmila Pliss

    Full Text Available Pyruvate dehydrogenase (PDH complex (PDC deficiency is an inborn error of pyruvate metabolism causing a variety of neurologic manifestations. Systematic analyses of development of affected brain structures and the cellular processes responsible for their impairment have not been performed due to the lack of an animal model for PDC deficiency.In the present study we investigated a murine model of systemic PDC deficiency by interrupting the X-linked Pdha1 gene encoding the α subunit of PDH to study its role on brain development and behavioral studies.Male embryos died prenatally but heterozygous females were born. PDC activity was reduced in the brain and other tissues in female progeny compared to age-matched control females. Immunohistochemical analysis of several brain regions showed that approximately 40% of cells were PDH(-. The oxidation of glucose to CO2 and incorporation of glucose-carbon into fatty acids were reduced in brain slices from 15 day-old PDC-deficient females. Histological analyses showed alterations in several structures in white and gray matters in 35 day-old PDC-deficient females. Reduction in total cell number and reduced dendritic arbors in Purkinje neurons were observed in PDC-deficient females. Furthermore, cell proliferation, migration and differentiation into neurons by newly generated cells were reduced in the affected females during pre- and postnatal periods. PDC-deficient mice had normal locomotor activity in a novel environment but displayed decreased startle responses to loud noises and there was evidence of abnormal pre-pulse inhibition of the startle reflex.The results show that a reduction in glucose metabolism resulting in deficit in energy production and fatty acid biosynthesis impairs cellular differentiation and brain development in PDC-deficient mice.

  10. Aeromonas caviae mimicking Vibrio cholerae infectious enteropathy in a cholera-endemic region with possible public health consequences: two case reports.

    Science.gov (United States)

    van Zwetselaar, Marco; Nyombi, Balthazar; Sonda, Tolbert; Kumburu, Happiness; Chamba, Nyasatu; Dekker, Marieke C J; Kilonzo, Kajiru G; Urasa, Sarah J; Mmbaga, Blandina T

    2018-03-17

    Aeromonas species have been documented to yield false positive results in microbiological tests for Vibrio cholerae. They share many biochemical properties with Vibrio species, with which they were jointly classified in the family Vibrionaceae until genotypic information provided new insights. Aeromonas species are increasingly associated with gastrointestinal infections, albeit with great apparent variation in pathogenicity and virulence both between and within species of the genus. We report two cases with clinically mild cholera-like symptoms, at a time when a cholera outbreak was unfolding in other regions of the country (Tanzania). These are the first cases to be reported with Aeromonas mimicking cholera in our area. Two patients were admitted at the isolation unit designated by the Kilimanjaro Christian Medical Centre for emerging infectious diseases and provided informed consent about regular stool analysis and culture under the provisional diagnosis of gastroenteritis. The first patient was a 23-year-old black African woman with a 2-day history of watery diarrhea and vomiting associated with a temperature of 39.7 °C. The second patient was a 47-year-old black African woman with a 2-day history of diarrhea and vomiting with a temperature of 37.7 °C, and she was hemodynamically stable. Both patients were isolated in a specific area for infection control and treated with fluids and orally administered rehydration solution, ciprofloxacin, metronidazole, and paracetamol. Stool culture was done. The isolated colonies were reported as V. cholerae and transferred to the research laboratory of Kilimanjaro Clinical Research Institute for confirmation using whole genome sequencing. Microbiological testing determined colonies isolated from stool to be V. cholerae, and warranted the conclusion "presumptive cholera." Whole genome sequencing, however, established the presence of Aeromonas caviae rather than V. cholerae. The co-existence of Aeromonas species with V

  11. St. John's Wort

    Science.gov (United States)

    ... St. John’s wort is a plant with yellow flowers that has been used in traditional European medicine ... E-mail: info@nccih.nih.gov PubMed® A service of the National Library of Medicine, PubMed® contains ...

  12. Candide in St. Louis

    Science.gov (United States)

    Yee, Roger

    1974-01-01

    A young, St. Louis, Missouri, architectural firm, seeking a personal style of practice, has succeeded in creating structures that reveal client input, and which are sensitive, articulate, and at ease with complexity. Describes an elementary school, a condominium, a shopping mall, a high school, and a "community mall." Illustrated with photographs…

  13. [Paracelsus in St. Gallen].

    Science.gov (United States)

    Ochsenbein, P

    1993-12-21

    Once, coming from Nürnberg, Paracelsus interrupted his journey and remained from 1531 to 1533 in the eastern part of Switzerland: First as personal physician of the severely ill mayor of St. Gall, Christian Studer, after the death of Studer (30. 12. 1531) he probably stayed in Roggenhalm near Bühler, a small village in the Canton of Appenzell. In most of the rare testimonies from citizens of St. Gall (Bartlome Schowinger, Johannes Rütiner, Vadian) about the man from Hohenheim he is described negatively as a rather unfavorable, unpleasant outsider. Vadian himself, to whom Paracelsus dedicated the third book of his "Opus Paramirum", obviously avoided him. In St. Gall Paracelsus wrote two prognostic scripts that were promptly printed in Zurich: The "Exposition of the Comet" and the "Exposition of the Arch of Peache". Rütiner tells in his diary about a (finally successful) surgical intervention on a hand operated by Paracelsus. Another successful treatment performed on a monk in December 1533, when he lived in Roggenheim, is registered in the expense-book of the abbot of St. Gall.

  14. Combined Hyperpolarized 13C-pyruvate MRS and 18F-FDG PET (HyperPET) Estimates of Glycolysis in Canine Cancer Patients

    DEFF Research Database (Denmark)

    Hansen, Adam E.; Gutte, Henrik; Holst, Pernille

    2018-01-01

    13C Magnetic Resonance Spectroscopy (MRS) using hyperpolarized 13C-labeled pyruvate as a substrate offers a measure of pyruvate-lactate interconversion and is thereby a marker of the elevated aerobic glycolysis (Warburg effect) generally exhibited by cancer cells. Here, we aim to compare hyperpol......13C Magnetic Resonance Spectroscopy (MRS) using hyperpolarized 13C-labeled pyruvate as a substrate offers a measure of pyruvate-lactate interconversion and is thereby a marker of the elevated aerobic glycolysis (Warburg effect) generally exhibited by cancer cells. Here, we aim to compare...... hyperpolarized [1-13C]pyruvate MRS with simultaneous 18F-2-fluoro-2-deoxy-D-glucose (FDG) PET in a cross-sectional study of canine cancer patients. Methods: Canine cancer patients underwent integrated PET/MRI using a clinical whole-body system. Hyperpolarized [1-13C]pyruvate was obtained using dissolution......-DNP. 18F-FDG PET, dynamic 13C MRS, 13C MRS Imaging (MRSI) and anatomical 1 H MRI was acquired from 17 patients. Apparent pyruvate-to-lactate rate constants were estimated from dynamic 13C MRS. 18F-FDG Standard Uptake Values and maximum [1-13C]lactate-to-total-13C ratios were obtained from tumor regions...

  15. Structural Basis for Flip-Flop Action of Thiamin Pyrophosphate-Dependent Enzymes Revealed by Human Pyruvate Dehydrogenase

    Science.gov (United States)

    Dominiak, Paulina; Ciszak, Ewa M.; Korotchkina, Lioubov; Sidhu, Sukhdeep; Patel, Mulchand

    2003-01-01

    Thiamin pyrophosphate (TPP), the biologically active form of vitamin BI, is a cofactor of enzymes catalyzing reactions involving the cleavage of a carbon-carbon bond adjacent to an oxo group. TPP-dependent enzymes show a common mechanism of TPP activation by: (1) forming the ionic N-H...O(sup -) hydrogen bonding between the N1' atom of the aminopirymidine ring of the coenzyme and intrinsic gamma-carboxylate group of glutamate and (2) imposing an "active" V-conformation that brings the N4' atom of the aminopirymidine to the distance required for the intramolecular C-H.. .N hydrogen bonding with the thiazolium C2 atom. Within these two hydrogen bonds that rapidly exchange protons, protonation of the N1' atom is strictly coordinated with the deprotonation of the 4' -amino group and eventually abstraction of the proton from C2. The human pyruvate dehydrogenase Elp, component of human pyruvate dehydrogenase complex, catalyzes the irreversible decarboxylation of the pyruvate followed by the reductive acetylation of the lipoyl group of dihydrolipoyl acyltransferase. Elp is alpha(sub 2)beta(sub2)-heterotetrameric with a molecular mass of I54 kDa, which has two catalytic sites, each providing TPP and magnesium ion as cofactors and each formed on the interface between the PP and PYR domains. The dynamic nonequivalence of two otherwise chemically equivalent catalytic sites has been observed and the flip-flop mechanism was suggested, according to which two active sites affect each other and in which different steps of the catalytic reaction are performed in each of the sites at any given moment. Based on specific futures of human pyruvate dehydrogenase including rigid and flexible connections between domains that bind the cofactor we propose a mechanistic model for the flip-flop action of this enzyme. We postulate that the dynamic protein environment drives the exchange of tautomers in the 4' -aminopyrimidine ring of the cofactor through a concerted shuttl-like motion of

  16. Adaptive mutations in sugar metabolism restore growth on glucose in a pyruvate decarboxylase negative yeast strain.

    Science.gov (United States)

    Zhang, Yiming; Liu, Guodong; Engqvist, Martin K M; Krivoruchko, Anastasia; Hallström, Björn M; Chen, Yun; Siewers, Verena; Nielsen, Jens

    2015-08-08

    A Saccharomyces cerevisiae strain carrying deletions in all three pyruvate decarboxylase (PDC) genes (also called Pdc negative yeast) represents a non-ethanol producing platform strain for the production of pyruvate derived biochemicals. However, it cannot grow on glucose as the sole carbon source, and requires supplementation of C2 compounds to the medium in order to meet the requirement for cytosolic acetyl-CoA for biosynthesis of fatty acids and ergosterol. In this study, a Pdc negative strain was adaptively evolved for improved growth in glucose medium via serial transfer, resulting in three independently evolved strains, which were able to grow in minimal medium containing glucose as the sole carbon source at the maximum specific rates of 0.138, 0.148, 0.141 h(-1), respectively. Several genetic changes were identified in the evolved Pdc negative strains by genomic DNA sequencing. Among these genetic changes, 4 genes were found to carry point mutations in at least two of the evolved strains: MTH1 encoding a negative regulator of the glucose-sensing signal transduction pathway, HXT2 encoding a hexose transporter, CIT1 encoding a mitochondrial citrate synthase, and RPD3 encoding a histone deacetylase. Reverse engineering of the non-evolved Pdc negative strain through introduction of the MTH1 (81D) allele restored its growth on glucose at a maximum specific rate of 0.053 h(-1) in minimal medium with 2% glucose, and the CIT1 deletion in the reverse engineered strain further increased the maximum specific growth rate to 0.069 h(-1). In this study, possible evolving mechanisms of Pdc negative strains on glucose were investigated by genome sequencing and reverse engineering. The non-synonymous mutations in MTH1 alleviated the glucose repression by repressing expression of several hexose transporter genes. The non-synonymous mutations in HXT2 and CIT1 may function in the presence of mutated MTH1 alleles and could be related to an altered central carbon metabolism in

  17. Pyruvate dehydrogenase complex and lactate dehydrogenase as targets for therapy of acute liver failure.

    Science.gov (United States)

    Ferriero, Rosa; Nusco, Edoardo; De Cegli, Rossella; Carissimo, Annamaria; Manco, Giuseppe; Brunetti-Pierri, Nicola

    2018-03-23

    Acute liver failure is a rapidly progressive deterioration of hepatic function resulting in high mortality and morbidity. Metabolic enzymes can translocate in the nucleus to regulate histone acetylation and gene expression. Levels and activities of pyruvate dehydrogenase complex (PDHC) and lactate dehydrogenase (LDH) were evaluated in nuclear fractions of livers of mice exposed to various hepatotoxins including CD95-Ab, α-amanitin, and acetaminophen. Whole-genome gene expression profiling by RNA-seq was performed in livers of mice with acute liver failure and analyzed by Gene Ontology Enrichment Analysis. Efficacy of histone acetyltransferase inhibitor garcinol and LDH inhibitor galloflavin at reducing liver damage was evaluated in mice with induced hepatotoxicity. Levels and activities of PDHC and LDH were increased in cytoplasmatic and nuclear fractions of livers of mice with acute liver failure. The increase of nuclear PDHC and LDH was associated with increased concentrations of acetyl-coA and lactate in nuclear fractions, and histone H3 hyper-acetylation. Gene expression in livers of mice with acute liver failure suggested that increased histone H3 acetylation induces the expression of genes related to response to damage. Reduced histone acetylation by the histone acetyltransferase inhibitor garcinol decreased liver damage and improved survival in mice with acute liver failure. Knock-down of PDHC or LDH improved viability in cells exposed to a pro-apoptotic stimulus. Treatment with the LDH inhibitor galloflavin that was also found to inhibit PDHC, reduced hepatic necrosis, apoptosis, and expression of pro-inflammatory cytokines in mice with acute liver failure. Mice treated with galloflavin also showed a dose-response increase in survival. PDHC and LDH translocate to the nucleus and are targets for therapy of acute liver failure. Acute liver failure is a rapidly progressive and life-threatening deterioration of liver function resulting in high mortality and

  18. Oliver St John Gogarty.

    Science.gov (United States)

    Clarke, R W

    1997-01-01

    Oliver St John Gogarty--Otolaryngologist to fashionable Edwardian Dublin--was a distinguished poet and a Senator in the fledgling Irish Free State after its establishment in 1922. He numbered amongst his acquaintances the poet William Butler Yeats, the novelist James Joyce and a host of political and literary persona who helped to shape modern Ireland. He was satirised as 'stately plump Buck Mulligan' in Joyce's novel Ulysses.

  19. The influence of Aloe vera and xenograft XCB toward of bone morpho protein 2 BMP2 expression and amount of osteoblast of alveolar bone induced into tooth extraction sockets Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2014-12-01

    Full Text Available Tooth extraction can cause inflammation leading to alveolar ridge resorption. In addition, prominent ridge has crucial role for making denture su-ccessfully. Thus, socket preservation is needed to prevent greater alveolar ridge resorption. An innovative material, a combination of Aloe vera and xe-nograft (XCB, is then considered as a biogenic stimulator that can reduce inflammation, as a result, the growth of alveolar bone is expected to be impro-ved. This research is aimed to prove whether the mixture of Aloe vera and xenograft can stimulate BMP2 and increase osteoblasts. Forty-eight Cavia co-baya animals were divided into eight groups each of which consisted of six animals. The mandibular incisors of those Cavia cobaya animals were then extracted and filled with PEG as Group Control, XCB as Group XCB, Aloe vera as Group Aloe vera, and a combination of Aloe vera +XCB as Group Aloe vera +XCB. Next, the first four groups were sacrificed seven days after extraction, and the second four groups were sacrificed 30 days after extrac-tion. And then, immunohistochemical and histopathology examinations were conducted to examine BMP2 expression and osteoblasts. Based on the re-sult known that the mixture of Aloe vera and xenograft can increase BMP2 expression and amount of osteoblasts. It can be concluded that the mixture of Aloe vera and xenograft can increase BMP2 expression and amount of osteoblast cel . It can be used as an alternative material to increase the growth of alveolar bone after extraction.

  20. Skin diseases in companion guinea pigs (Cavia porcellus): a retrospective study of 293 cases seen at the Veterinary Medical Teaching Hospital, University of California at Davis (1990-2015).

    Science.gov (United States)

    White, Stephen D; Guzman, David Sanchez-Migallon; Paul-Murphy, Joanne; Hawkins, Michelle G

    2016-10-01

    Guinea pigs (Cavia porcellus) are popular companion animals with reported skin diseases, but most reports are accessed from textbooks or review articles. To document skin diseases and their prevalence in companion guinea pigs in northern California, USA, and to investigate predilections for the most common conditions over a 25 year period. Two hundred and ninety three guinea pigs from the hospital population met inclusion criteria. A retrospective study was performed by searching computerized medical records seen at the Veterinary Medical Teaching Hospital (VMTH), School of Veterinary Medicine, University of California from 1 January 1990 to 31 July 2015 using key words relevant to dermatology. Of the 580 guinea pigs seen at the VMTH, 50% (293) had skin disease. Of the 293 cases, 154 (52%) presented for nondermatological reasons. Guinea pigs with skin disease were significantly older than those without skin disease (P = 0.0002); females with skin disease were more likely to have cystic ovaries (P = 0.0203), although these were not always associated with alopecia. Pododermatitis and infestation with Trixacarus caviae or lice were the most common skin diseases. Ivermectin or selamectin was used for ectoparasite treatment. Abscesses unassociated with pododermatitis were the most common nodules. Benign follicular tumours were the most common neoplasm. Despite the frequent mention of dermatophytosis in the veterinary literature, only two cases of Trichophyton mentagrophytes were diagnosed. Cutaneous conditions in companion guinea pigs in the USA are common. Clinicians should include a dermatological examination when examining these rodents regardless of the reason for presentation. © 2016 ESVD and ACVD.

  1. Effets de Panicum maximum Jacq. associé à Euphorbia heterophylla (L. Klotz. & Garcke sur la productivité des femelles durant le cycle de reproduction chez le cobaye (Cavia porcellus L.

    Directory of Open Access Journals (Sweden)

    N'G. D.V. Kouakou

    2015-01-01

    Full Text Available Effect of Panicum maximum Jacq. Associated with Euphorbia heterophylla (L. Klotz. & Garcke on Productivity of Females (Cavia porcellus L During the Reproductive Cycle. In Ivory Coast, Guinea pigs reared for meat (Cavia porcellus L. are mainly fed with Panicum maximum Jacq. The association of this forage with Euphorbia heterophylla (L. Klotz. & Garcke improves the organic matter digestibility of the mixed diet compared to P. maximum distributed alone in growing male guinea pigs. In order to determine the effect of this diet during gestation and lactation in female guinea pigs, three diets: P. maximum (PAN basic diet; P. maximum associated to E. heterophylla (PANEUPH and P. maximum associated to pellets for rabbit (PANGRAN, were distributed ad libitum to multiparous guinea pigs (604.9 ± 40.8 g. The daily ingestion during gestation and lactation were 59.8±11.2 and 53.2±8.5; 61.5±5.2 and 72.9±16.4; 83.1±12.9 and 111.3±13.9 g DM.d-1 respectively for PAN, PANEUPH and PANGRAN. Similarly, the rates of fecundity were 111.1±0.9; 188.9±0.6 and 244.4±0.5% respectively for PAN, PANEUPH and PANGRAN. The individual birth weight and weight gain during lactation of the piglets were 58.7±12.4, 75.6±16.2 and 102.5±12 g and 2.4±0.6; 4.1±0.9 and 6.5±1.2 g.d-1 respectively for PAN, PANEUPH, and PANGRAN. In conclusion, the association of P. maximum and E. heterophylla significantly improves ingestion, digestibility, fecundity, birth weight and weaning weight in guinea pigs in comparison to Panicum maximum used as a sole diet.

  2. ST Safety What's on?

    CERN Document Server

    Jacot, C

    2001-01-01

    Du premier coup de pioche jusqu'à la mise en place de la tente abritant le buffet offert lors de la cérémonie d'achèvement d'un projet, la division ST est sur les rangs et apporte son savoir faire. Ces projets nombreux et pluridisciplinaires sont étudiés, se réalisent, s'exploitent et font l'objet de maintenance jusqu'à leur démantèlement. Durant leurs cycles de vie, la division ST avance les compétences professionnelles spécifiques à chaque corps de métiers incluant le recours à de nombreux contrats avec des entreprises extérieures pour réaliser les travaux sur les sites du CERN. Pour en conserver la maîtrise, la division ST applique une gestion de projet, une assurance de la qualité et s'attache tout particulièrement à la sécurité, à la réglementation, à la prévention des risques et la gestion de ceux-ci. Sous la supervision du DSO, un ensemble de procédures et de démarches a été développé afin de faciliter les tâches du maître d'ouvrage et des entreprises contractantes, c...

  3. St. John's Wort.

    Science.gov (United States)

    Field, H L; Monti, D A; Greeson, J M; Kunkel, E J

    2000-01-01

    The objective of this article is to review the current knowledge of the pharmacology, sites of action, and therapeutic effectiveness of St. John's Wort. The method used was a review of the available literature, using keywords to search the medline database. Bibliographies of the papers, thus obtained, were searched for further documents not referenced by medline. We reviewed papers from this collection. This review reveals that most of the available data on efficacy and safety of St. John's Wort involve its use in mild to moderate depression. Much, but not all of the prevailing opinion is positive. Nevertheless, the quality of therapeutic trials vary so greatly that definitive conclusions are not possible. Both the source and mode of St. John's Wort's therapeutic effect are unclear. We need further controlled studies of effectiveness, safety, and mode of action. In addition to its use in depression, there are reports suggesting possible therapeutic effects in other conditions such as certain malignancies and infections, but these are far too preliminary to permit any conclusions.

  4. Formation and utilization of acetoin, an unusual product of pyruvate metabolism by Ehrlich and AS30-D tumor mitochondria.

    Science.gov (United States)

    Baggetto, L G; Lehninger, A L

    1987-07-15

    [14C]Pyruvate was rapidly non-oxidatively decarboxylated by Ehrlich tumor mitochondria at a rate of 40 nmol/min/mg of protein in the presence or absence of ADP. A search for decarboxylation products led to significant amounts of acetoin formed when Ehrlich tumor mitochondria were incubated with 1 mM [14C] pyruvate in the presence of ATP. Added acetoin to aerobic tumor mitochondria was rapidly utilized in the presence of ATP at a rate of 65 nmol/min/mg of protein. Citrate has been found as a product of acetoin utilization and was exported from the tumor mitochondria. Acetoin has been found in the ascitic liquid of Ehrlich and AS30-D tumor-bearing animals. These unusual reactions were not observed in control rat liver mitochondria.

  5. [The effect of succinate on respiration, transamination, and pyruvate formation in cells of the yeast Dipodascus magnusii].

    Science.gov (United States)

    Il'chenko, A P; Ogorelyshev, D I; Shishkanova, N V; Sokolov, A P; Finogenova, T V; Kondrashova, M N

    2005-01-01

    The effect of succinate on the growth and respiration of the yeast Dipodascus magnusii VKM Y-1072, which is auxotrophic for thiamine and biotin, was studied. The addition of succinate to a culture grown on glucose was found to activate the respiration of cells on various substrates by enhancing the processes related to transamination reactions. In this case, aerobic fermentation (ethanol production) decreased, whereas pyruvate production increased. When succinate was added to the medium as the sole carbon source, it supported yeast growth in the absence of one of the two vitamins, thiamine or biotin, but not both. The yeast metabolism was completely respiratory, without any signs of aerobic fermentation. A drastic rise in pyruvate production in the yeast grown on glucose in the presence of succinate and the absence of biotin are also indicative of metabolic changes.

  6. Arsanilic acid-Sepharose chromatography of pyruvate kinase from KB cells.

    Science.gov (United States)

    Huang, R N; Yeh, H Y; Cheng, S C; Chow, L P; Lee, T C

    2000-03-31

    In the present study, arsanical-based affinity chromatography for pyruvate kinase (PK) isolation was explored. p-Arsanilic acid (4-aminophenyl arsonic acid), which contains an arsonic acid moiety structurally similar to inorganic pentavalent arsenate, was conjugated to Sepharose 4B via its para-amino group to form an As(V)-Sepharose matrix. The cellular proteins from KB cells bound to arsonic acid moieties were eluted by 50 mM sodium arsenate in Tris-HCl buffer (50 mM, pH 7.6). A single protein band with a molecular mass of 58 kDa was shown on a sodium dodecyl sulfate-polyacrylamide gel. By immunoblotting, amino acid sequencing and enzymatic analysis, the sodium arsenate-eluted 58-kDa protein was demonstrated to be a human PK (type M2). By using this one-step As(V)-Sepharose chromatography, PK from KB cells was purified 35.4-fold with a specific activity of 153.15 U/mg protein in the presence of 6 mM fructose-1,6-biphosphate. Although PK was eluted from an As(V)-Sepharose column with sodium arsenate, PK activity was apparently inhibited by the used eluent system, but not by p-arsanilic acid, indicating a specific interaction of As(V) to PK. In summary, our results indicate that As(V)-Sepharose can serve as a simple and efficient chromatographic support for PK purification from KB cells.

  7. Pyruvate kinase isoform expression alters nucleotide synthesis to impact cell proliferation

    Science.gov (United States)

    Lunt, Sophia Y.; Muralidhar, Vinayak; Hosios, Aaron M.; Israelsen, William J.; Gui, Dan Y.; Newhouse, Lauren; Ogrodzinski, Martin; Hecht, Vivian; Xu, Kali; Acevedo, Paula N. Marín; Hollern, Daniel P.; Bellinger, Gary; Dayton, Talya L.; Christen, Stefan; Elia, Ilaria; Dinh, Anh T.; Stephanopoulos, Gregory; Manalis, Scott R.; Yaffe, Michael B.; Andrechek, Eran R.; Fendt, Sarah-Maria; Heiden, Matthew G. Vander

    2014-01-01

    SUMMARY Metabolic regulation influences cell proliferation. The influence of pyruvate kinase isoforms on tumor cells has been extensively studied, but whether PKM2 is required for normal cell proliferation is unknown. We examine how PKM2-deletion affects proliferation and metabolism in non-transformed, non-immortalized PKM2-expressing primary cells. We find that deletion of PKM2 in primary cells results in PKM1 expression and proliferation arrest. PKM1 expression, rather than PKM2 loss, is responsible for this effect, and proliferation arrest cannot be explained by cell differentiation, senescence, death, changes in gene expression, or prevention of cell growth. Instead, PKM1 expression impairs nucleotide production and the ability to synthesize DNA and progress through the cell cycle. Nucleotide biosynthesis is limiting, as proliferation arrest is characterized by severe thymidine depletion, and supplying exogenous thymine rescues both nucleotide levels and cell proliferation. Thus, PKM1 expression promotes a metabolic state that is unable to support DNA synthesis. PMID:25482511

  8. A new family of covalent inhibitors block nucleotide binding to the active site of pyruvate kinase.

    Science.gov (United States)

    Morgan, Hugh P; Walsh, Martin J; Blackburn, Elizabeth A; Wear, Martin A; Boxer, Matthew B; Shen, Min; Veith, Henrike; McNae, Iain W; Nowicki, Matthew W; Michels, Paul A M; Auld, Douglas S; Fothergill-Gilmore, Linda A; Walkinshaw, Malcolm D

    2012-11-15

    PYK (pyruvate kinase) plays a central role in the metabolism of many organisms and cell types, but the elucidation of the details of its function in a systems biology context has been hampered by the lack of specific high-affinity small-molecule inhibitors. High-throughput screening has been used to identify a family of saccharin derivatives which inhibit LmPYK (Leishmania mexicana PYK) activity in a time- (and dose-) dependent manner, a characteristic of irreversible inhibition. The crystal structure of DBS {4-[(1,1-dioxo-1,2-benzothiazol-3-yl)sulfanyl]benzoic acid} complexed with LmPYK shows that the saccharin moiety reacts with an active-site lysine residue (Lys335), forming a covalent bond and sterically hindering the binding of ADP/ATP. Mutation of the lysine residue to an arginine residue eliminated the effect of the inhibitor molecule, providing confirmation of the proposed inhibitor mechanism. This lysine residue is conserved in the active sites of the four human PYK isoenzymes, which were also found to be irreversibly inhibited by DBS. X-ray structures of PYK isoforms show structural differences at the DBS-binding pocket, and this covalent inhibitor of PYK provides a chemical scaffold for the design of new families of potentially isoform-specific irreversible inhibitors.

  9. In vitro synthesis of the pyruvate dehydrogenase complex components of Ascaris suum mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Desai, S.; Ruff, V.; DuBrul, E.F.; Komuniecki, R.W.

    1987-05-01

    The pyruvate dehydrogenase complex (PDC) plays a pivotal role in the anaerobic metabolism of Ascaris suum mitochondria. They have initiated a series of studies on the in vitro synthesis and mitochondrial import of PDC. PDC has been purified from adult Ascaris body wall muscle, fully phosphorylated in vitro, and separated into its component subunits on SDS/PAGE. The individual components were electroeluted from the gels and used to immunize rabbits. IgG's to the individual subunits were prepared from antisera and their specificities were verified by immuno-blotting. Each IgG identified a single specific band at the appropriate location in extracts of adult Ascaris body wall muscle mitochondria. Poly A/sup +/-RNA was prepared from body wall muscle and translated in a reticylocyte lysate system using /sup 35/S-methionine. Translation products were immunoprecipitated with specific IgG's, electrophoresed, and fluorographed. Each immunoprecipitation gave rise to a single radioactive polypeptide that was slightly larger than the specific PDC subunit isolated from the adult mitochondria. This system has demonstrated its feasibility for the study of mitochondrial import of a multienzyme complex that is critical for the anaerobic mitochondrial metabolism of Ascaris suum.

  10. Succinate-dependent energy generation and pyruvate dehydrogenase complex activity in isolated Ascaris suum mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, T.A.

    1988-01-01

    Body wall muscle from the parasitic nematode, Ascaris suum, contain unique anaerobic mitochondria that preferentially utilize fumarate and branched-chain enoyl CoA's as terminal electron acceptors instead of oxygen. While electron transport in these organelles is well characterized, the role of oxygen in succinate-dependent phosphorylation is still not clearly defined. Therefore, the present study was designed to more fully characterize succinate metabolism in these organelles as well as the in vitro regulation of a key mitochondrial enzyme, the pyruvate dehydrogenase complex (PDC). In the absence of added adenine nucleotides, incubations in succinate resulted in substantial elevations in intramitochrondrial ATP levels, but ATP/ADP ratios were considerably higher in incubations with malate. The stimulation of phosphorylation in aerobic incubations with succinate was rotenone sensitive and appears to be Site I dependent. Increase substrate level phosphorylation, coupled to propionate formation, or additional sites of electron-transport associated ATP synthesis were not significant. Under aerobic conditions, {sup 14}CO{sub 2} evolution from 1,4-({sup 14}C)succinate was stimulated and NADH/NAD{sup +} ratios were elevated, but the formation of {sup 14}C propionate was unchanged.

  11. Ameliorative effect of ethyl pyruvate in neuropathic pain induced by chronic constriction injury of sciatic nerve

    Directory of Open Access Journals (Sweden)

    Varsha J. Bansode

    2014-01-01

    Full Text Available Objective: The present study was designed to investigate the ameliorative effects of ethyl pyruvate (EP in chronic constriction injury (CCI-induced painful neuropathy in rats. Materials and Methods: EP 50 and 100 mg/kg was administered for 21 consecutive days starting from the day of surgery. The effects of EP in the paw pressure, acetone drop, and tail heat immersion tests were assessed, reflecting the degree of mechanical hyperalgesia, cold allodynia, and spinal thermal sensation, respectively. Axonal degeneration of the sciatic nerve was assessed histopathologically. The levels of thiobarbituric acid reactive species, reduced glutathione (GSH, catalase (CAT, and superoxide dismutase (SOD were determined to assess oxidative stress. Key Findings: Administration of 50 and 100 mg/kg EP attenuated the reduction of nociceptive threshold in the paw pressure, acetone drop, and tail heat immersion tests. EP 100 mg/kg significantly attenuated reactive changes in histopathology and increase in oxidative stress. Conclusion: EP 100 mg/kg showed beneficial activity against nerve trauma-induced neuropathy. Hence, it can be used as a better treatment option in neuropathic pain (NP. The observed antinociceptive effects of EP may possibly be attributed to its antioxidant and anti-inflammatory activity.

  12. Benchmarking predictions of allostery in liver pyruvate kinase in CAGI4.

    Science.gov (United States)

    Xu, Qifang; Tang, Qingling; Katsonis, Panagiotis; Lichtarge, Olivier; Jones, David; Bovo, Samuele; Babbi, Giulia; Martelli, Pier L; Casadio, Rita; Lee, Gyu Rie; Seok, Chaok; Fenton, Aron W; Dunbrack, Roland L

    2017-09-01

    The Critical Assessment of Genome Interpretation (CAGI) is a global community experiment to objectively assess computational methods for predicting phenotypic impacts of genomic variation. One of the 2015-2016 competitions focused on predicting the influence of mutations on the allosteric regulation of human liver pyruvate kinase. More than 30 different researchers accessed the challenge data. However, only four groups accepted the challenge. Features used for predictions ranged from evolutionary constraints, mutant site locations relative to active and effector binding sites, and computational docking outputs. Despite the range of expertise and strategies used by predictors, the best predictions were marginally greater than random for modified allostery resulting from mutations. In contrast, several groups successfully predicted which mutations severely reduced enzymatic activity. Nonetheless, poor predictions of allostery stands in stark contrast to the impression left by more than 700 PubMed entries identified using the identifiers "computational + allosteric." This contrast highlights a specialized need for new computational tools and utilization of benchmarks that focus on allosteric regulation. © 2017 Wiley Periodicals, Inc.

  13. Acute hypertensive stress imaged by cardiac hyperpolarized [1-C]pyruvate magnetic resonance

    DEFF Research Database (Denmark)

    Tougaard, Rasmus Stilling; Hansen, Esben Søvsø Szocska; Laustsen, Christoffer

    2018-01-01

    PURPOSE: Deranged metabolism is now recognized as a key causal factor in a variety of heart diseases, and is being studied extensively. However, invasive methods may alter metabolism, and conventional imaging techniques measure tracer uptake but not downstream metabolism. These challenges may...... be overcome by hyperpolarized MR, a noninvasive technique currently crossing the threshold into human trials. The aim of this study was to image metabolic changes in the heart in response to endogastric glucose bolus and to acute hypertension. METHODS: Five postprandial pigs were scanned with hyperpolarized.......008) and ejection fraction decreased from 54 ± 2% to 47 ± 6% (P = 0.03) The hemodynamic changes were accompanied by increases in the hyperpolarized [1-13C]pyruvate MR derived ratios of lactate/alanine (from 0.58 ± 0.13 to 0.78 ± 0.06, P = 0.03) and bicarbonate/alanine (from 0.55 ± 0.12 to 0.91 ± 0.14, P = 0...

  14. Control of biotin biosynthesis in mycobacteria by a pyruvate carboxylase dependent metabolic signal.

    Science.gov (United States)

    Lazar, Nathaniel; Fay, Allison; Nandakumar, Madhumitha; Boyle, Kerry E; Xavier, Joao; Rhee, Kyu; Glickman, Michael S

    2017-12-01

    Biotin is an essential cofactor utilized by all domains of life, but only synthesized by bacteria, fungi and plants, making biotin biosynthesis a target for antimicrobial development. To understand biotin biosynthesis in mycobacteria, we executed a genetic screen in Mycobacterium smegmatis for biotin auxotrophs and identified pyruvate carboxylase (Pyc) as required for biotin biosynthesis. The biotin auxotrophy of the pyc::tn strain is due to failure to transcriptionally induce late stage biotin biosynthetic genes in low biotin conditions. Loss of bioQ, the repressor of biotin biosynthesis, in the pyc::tn strain reverted biotin auxotrophy, as did reconstituting the last step of the pathway through heterologous expression of BioB and provision of its substrate DTB. The role of Pyc in biotin regulation required its catalytic activities and could be supported by M. tuberculosis Pyc. Quantitation of the kinetics of depletion of biotinylated proteins after biotin withdrawal revealed that Pyc is the most rapidly depleted biotinylated protein and metabolomics revealed a broad metabolic shift in wild type cells upon biotin withdrawal which was blunted in cell lacking Pyc. Our data indicate that mycobacterial cells monitor biotin sufficiency through a metabolic signal generated by dysfunction of a biotinylated protein of central metabolism. © 2017 John Wiley & Sons Ltd.

  15. Posttranslational Modifications of Pyruvate Kinase M2: Tweaks that Benefit Cancer

    Directory of Open Access Journals (Sweden)

    Gopinath Prakasam

    2018-02-01

    Full Text Available Cancer cells rewire metabolism to meet biosynthetic and energetic demands. The characteristic increase in glycolysis, i.e., Warburg effect, now considered as a hallmark, supports cancer in various ways. To attain such metabolic reshuffle, cancer cells preferentially re-express the M2 isoform of pyruvate kinase (PKM2, M2-PK and alter its quaternary structure to generate less-active PKM2 dimers. The relatively inactive dimers cause the accumulation of glycolytic intermediates that are redirected into anabolic pathways. In addition, dimeric PKM2 also benefits cancer cells through various non-glycolytic moonlight functions, such as gene transcription, protein kinase activity, and redox balance. A large body of data have shown that several distinct posttranslation modifications (PTMs regulate PKM2 in a way that benefits cancer growth, e.g., formation of PKM2 dimers. This review discusses the recent advancements in our understanding of various PTMs and the benefits they impart to the sustenance of cancer. Understanding the PTMs in PKM2 is crucial to assess their therapeutic potential and to design novel anticancer strategies.

  16. Metabolic modeling of energy balances in Mycoplasma hyopneumoniae shows that pyruvate addition increases growth rate.

    Science.gov (United States)

    Kamminga, Tjerko; Slagman, Simen-Jan; Bijlsma, Jetta J E; Martins Dos Santos, Vitor A P; Suarez-Diez, Maria; Schaap, Peter J

    2017-10-01

    Mycoplasma hyopneumoniae is cultured on large-scale to produce antigen for inactivated whole-cell vaccines against respiratory disease in pigs. However, the fastidious nutrient requirements of this minimal bacterium and the low growth rate make it challenging to reach sufficient biomass yield for antigen production. In this study, we sequenced the genome of M. hyopneumoniae strain 11 and constructed a high quality constraint-based genome-scale metabolic model of 284 chemical reactions and 298 metabolites. We validated the model with time-series data of duplicate fermentation cultures to aim for an integrated model describing the dynamic profiles measured in fermentations. The model predicted that 84% of cellular energy in a standard M. hyopneumoniae cultivation was used for non-growth associated maintenance and only 16% of cellular energy was used for growth and growth associated maintenance. Following a cycle of model-driven experimentation in dedicated fermentation experiments, we were able to increase the fraction of cellular energy used for growth through pyruvate addition to the medium. This increase in turn led to an increase in growth rate and a 2.3 times increase in the total biomass concentration reached after 3-4 days of fermentation, enhancing the productivity of the overall process. The model presented provides a solid basis to understand and further improve M. hyopneumoniae fermentation processes. Biotechnol. Bioeng. 2017;114: 2339-2347. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Brain Glycogenolysis, Adrenoceptors, Pyruvate Carboxylase, Na+,K+-ATPase and Marie E. Gibbs’ Pioneering Learning Studies

    Directory of Open Access Journals (Sweden)

    Leif eHertz

    2013-04-01

    Full Text Available The involvement of glycogenolysis, occurring in astrocytes but not in neurons, in learning is undisputed (Duran et al., JCBFM, in press. According to one school of thought the role of astrocytes for learning is restricted to supply of substrate for neuronal oxidative metabolism. The present ‘perspective’ suggests a more comprehensive and complex role, made possible by lack of glycogen degradation, unless specifically induced by either i activation of astrocytic receptors, perhaps especially beta-adrenergic, or ii even small increases in extracellular K+ concentration above its normal resting level. It discusses i the known importance of glycogenolysis for glutamate formation, requiring pyruvate carboxylation; ii the established role of K+-stimulated glycogenolysis for K+ uptake in cultured astrocytes, which probably indicates that astrocytes are an integral part of cellular K+ homeostasis in the brain in vivo; and iii the plausible role of transmitter-induced glycogenolysis, stimulating Na+,K+-ATPase/NKCC1 activity and thereby contributing both to the post-excitatory undershoot in extracellular K+ concentration and the memory-enhancing effect of transmitter-mediated reduction of slow neuronal afterhyperpolarization (sAHP.

  18. Regulation of Muscle Pyruvate Dehydrogenase Complex in Insulin Resistance: Effects of Exercise and Dichloroacetate

    Directory of Open Access Journals (Sweden)

    Dumitru Constantin-Teodosiu

    2013-10-01

    Full Text Available Since the mitochondrial pyruvate dehydrogenase complex (PDC controls the rate of carbohydrate oxidation, impairment of PDC activity mediated by high-fat intake has been advocated as a causative factor for the skeletal muscle insulin resistance, metabolic syndrome, and the onset of type 2 diabetes (T2D. There are also situations where muscle insulin resistance can occur independently from high-fat dietary intake such as sepsis, inflammation, or drug administration though they all may share the same underlying mechanism, i.e., via activation of forkhead box family of transcription factors, and to a lower extent via peroxisome proliferator-activated receptors. The main feature of T2D is a chronic elevation in blood glucose levels. Chronic systemic hyperglycaemia is toxic and can lead to cellular dysfunction that may become irreversible over time due to deterioration of the pericyte cell's ability to provide vascular stability and control to endothelial proliferation. Therefore, it may not be surprising that T2D's complications are mainly macrovascular and microvascular related, i.e., neuropathy, retinopathy, nephropathy, coronary artery, and peripheral vascular diseases. However, life style intervention such as exercise, which is the most potent physiological activator of muscle PDC, along with pharmacological intervention such as administration of dichloroacetate or L-carnitine can prove to be viable strategies for treating muscle insulin resistance in obesity and T2D as they can potentially restore whole body glucose disposal.

  19. Protective effect of ethyl pyruvate on pancreas injury in rats with severe acute pancreatitis.

    Science.gov (United States)

    Luan, Zheng-Gang; Ma, Xiao-Chun; Zhang, Hao; Zhang, Cheng; Guo, Ren-Xuan

    2013-05-01

    Systemic inflammatory mediators have an important role in the development of acute pancreatitis. In this study, we investigated the effect of ethyl pyruvate (EP) on pancreas injury in rats with severe acute pancreatitis (SAP) and its possible mechanism. We randomly allocated rats into the following three experimental groups: control and SAP- and EP-treated. Then, we recorded the mortality rate. We harvested tissue specimens for morphological studies, streptavidin-peroxidase immunohistochemistry examination, and Western blot analysis. We tested the levels of pancreatic tissue malondialdehyde and the activity of serum amylase, myeloperoxidase in the pancreas. In addition, we studied nuclear factor-κB (NF-κB) activation, tumor necrosis factor-α levels, and high mobility group box 1 protein expression levels in the pancreas. Treatment with EP after SAP was associated with a reduction in the severity of SAP and pancreas injury. Treatment with EP significantly decreased the expression of tumor necrosis factor-α and high mobility group box 1, and ameliorated malondialdehyde concentration and myeloperoxidase activity in the pancreas in SAP rats. Compared with the SAP group, treatment with EP significantly decreased the number of inflammatory cell infiltration, markedly inhibited pancreatic NF-κB DNA binding, and increased the survival rates. This study demonstrates that preventing the activation of NF-κB by EP ameliorates tissue injury associated with experimental murine acute pancreatitis. This result provides an important insight into the molecular biology of acute pancreatitis. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Lapachol inhibits glycolysis in cancer cells by targeting pyruvate kinase M2.

    Directory of Open Access Journals (Sweden)

    Mani Shankar Babu

    Full Text Available Reliance on aerobic glycolysis is one of the hallmarks of cancer. Although pyruvate kinase M2 (PKM2 is a key mediator of glycolysis in cancer cells, lack of selective agents that target PKM2 remains a challenge in exploiting metabolic pathways for cancer therapy. We report that unlike its structural analog shikonin, a known inhibitor of PKM2, lapachol failed to induce non-apoptotic cell death ferroxitosis in hypoxia. However, melanoma cells treated with lapachol showed a dose-dependent inhibition of glycolysis and a corresponding increase in oxygen consumption. Accordingly, in silico studies revealed a high affinity-binding pocket for lapachol on PKM2 structure. Lapachol inhibited PKM2 activity of purified enzyme as well as in melanoma cell extracts. Blockade of glycolysis by lapachol in melanoma cells led to decreased ATP levels and inhibition of cell proliferation. Furthermore, perturbation of glycolysis in melanoma cells with lapachol sensitized cells to mitochondrial protonophore and promoted apoptosis. These results present lapachol as an inhibitor of PKM2 to interrogate metabolic plasticity in tumor cells.

  1. Switching of pyruvate kinase isoform L to M2 promotes metabolic reprogramming in hepatocarcinogenesis.

    Directory of Open Access Journals (Sweden)

    Carmen Chak-Lui Wong

    Full Text Available Hepatocellular carcinoma (HCC is an aggressive tumor, with a high mortality rate due to late symptom presentation and frequent tumor recurrences and metastasis. It is also a rapidly growing tumor supported by different metabolic mechanisms; nevertheless, the biological and molecular mechanisms involved in the metabolic reprogramming in HCC are unclear. In this study, we found that pyruvate kinase M2 (PKM2 was frequently over-expressed in human HCCs and its over-expression was associated with aggressive clinicopathological features and poor prognosis of HCC patients. Furthermore, knockdown of PKM2 suppressed aerobic glycolysis and cell proliferation in HCC cell lines in vitro. Importantly, knockdown of PKM2 hampered HCC growth in both subcutaneous injection and orthotopic liver implantation models, and reduced lung metastasis in vivo. Of significance, PKM2 over-expression in human HCCs was associated with a down-regulation of a liver-specific microRNA, miR-122. We further showed that miR-122 interacted with the 3UTR of the PKM2 gene. Re-expression of miR-122 in HCC cell lines reduced PKM2 expression, decreased glucose uptake in vitro, and suppressed HCC tumor growth in vivo. Our clinical data and functional studies have revealed a novel biological mechanism involved in HCC metabolic reprogramming.

  2. An improved strategy for the crystallization of Leishmania mexicana pyruvate kinase

    International Nuclear Information System (INIS)

    Morgan, Hugh P.; McNae, Iain W.; Hsin, Kun-Yi; Michels, Paul A. M.; Fothergill-Gilmore, Linda A.; Walkinshaw, Malcolm D.

    2010-01-01

    The first crystal structure of Leishmania mexicana pyruvate kinase (LmPYK) obtained at a neutral pH. LmPYK was co-crystallized with the small molecule 1,3,6,8-pyrenetetrasulfonic acid, which provides a helpful intermolecular bridge between macromolecules. The inclusion of novel small molecules in crystallization experiments has provided very encouraging results and this method is now emerging as a promising alternative strategy for crystallizing ‘problematic’ biological macromolecules. These small molecules have the ability to promote lattice formation through stabilizing intermolecular interactions in protein crystals. Here, the use of 1,3,6,8-pyrenetetrasulfonic acid (PTS), which provides a helpful intermolecular bridge between Leishmania mexicana PYK (LmPYK) macromolecules in the crystal, is reported, resulting in the rapid formation of a more stable crystal lattice at neutral pH and greatly improved X-ray diffraction results. The refined structure of the LmPYK–PTS complex revealed the negatively charged PTS molecule to be stacked between positively charged (surface-exposed) arginine side chains from neighbouring LmPYK molecules in the crystal lattice

  3. Ethyl pyruvate reduces hepatic mitochondrial swelling and dysfunction in a rat model of sepsis.

    Science.gov (United States)

    Jiang, Zhiyi; Li, Xiaoyue; Lin, Zongqin; Chen, Juan; Guan, Xiangdong; Chen, Minying

    2015-01-01

    Sepsis causes mitochondrial oxidative injury and swelling. Ethyl pyruvate (EP) is a cytoprotective agent, while aquaporin-8 (AQP8) is a mitochondrial water channel that can induce mitochondrial swelling. We assessed whether EP protects mitochondria during sepsis, and whether AQP8 contributes to the underlying mechanisms. A cecal ligation and puncture (CLP) sepsis model was established in Sprague-Dawley rats, randomized to 3 groups: sham (n=20), CLP (n=59) and CLP+EP (n=51). All rats received postoperative intraperitoneal fluid resuscitation (30 ml/kg); the CLP+EP group also received intraperitoneal EP (100 mg/kg). Survival was assessed at 24 hours. Hepatic mitochondrial ultrastructure was characterized by electron microscopy. The membrane potential of isolated hepatic mitochondria was determined using JC-1 and flow cytometry. Mitochondrial AQP8 expression and cytochrome C (Cyt C) release were measured by Western blotting (values normalized to ß-actin). Survival in the sham, CLP and CLP+EP groups was 100%, 21% and 41%, respectively. Mitochondrial cross-sectional area was smaller in the CLP+EP group than in the CLP group (0.231±0.110 vs. 0.641±0.460 µm(2); Psepsis outcome by targeting the mitochondrion, possibly through modulation of AQP8 expression.

  4. Pyruvate Kinase and Fcγ Receptor Gene Copy Numbers Associated With Malaria Phenotypes.

    Science.gov (United States)

    Faik, Imad; van Tong, Hoang; Lell, Bertrand; Meyer, Christian G; Kremsner, Peter G; Velavan, Thirumalaisamy P

    2017-07-15

    Genetic factors are associated with susceptibility to many infectious diseases and may be determinants of clinical progression. Gene copy number variation (CNV) has been shown to be associated with phenotypes of numerous diseases, including malaria. We quantified gene copy numbers of the pyruvate kinase, liver, and red blood cell (PKLR) gene as well as of the Fcγ receptor 2A and Fcγ receptor 2C (FCGR2A, FCGR2C) and Fcγ receptor 3 (FCGR3) genes using real-time quantitative polymerase chain reaction (RT-qPCR) assays in Gabonese children with severe (n = 184) or and mild (n = 189) malaria and in healthy Gabonese and white individuals (n = 76 each). The means of PKLR, FCGR2A, FCGR2C, and FCGR3 copy numbers were significantly higher among children with severe malaria compared to those with mild malaria (P malaria severity. Copy numbers of the FCGR2A and FCGR2C genes were significantly lower (P = .005) in Gabonese individuals compared with white individuals. In conclusion, CNV of the PKLR, FCGR2A, FCGR2C, and FCGR3 genes is associated with malaria severity, and our results provide evidence for a role of CNV in host responses to malaria. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  5. Radial spectroscopic MRI of hyperpolarized [1-(13) C] pyruvate at 7 tesla.

    Science.gov (United States)

    Ramirez, Marc S; Lee, Jaehyuk; Walker, Christopher M; Sandulache, Vlad C; Hennel, Franciszek; Lai, Stephen Y; Bankson, James A

    2014-10-01

    The transient and nonrenewable signal from hyperpolarized metabolites necessitates extensive sequence optimization for encoding spatial, spectral, and dynamic information. In this work, we evaluate the utility of radial single-timepoint and cumulative spectroscopic MRI of hyperpolarized [1-(13) C] pyruvate and its metabolic products at 7 Tesla (T). Simulations of radial echo planar spectroscopic imaging (EPSI) and multiband frequency encoding (MBFE) acquisitions were performed to confirm feasibility and evaluate performance for HP (13) C imaging. Corresponding sequences were implemented on a 7T small-animal MRI system, tested in phantom, and demonstrated in a murine model of anaplastic thyroid cancer. MBFE provides excellent spectral separation but is susceptible to blurring and T2 * signal loss inherent to using low readout gradients. The higher readout gradients and more flexible spectral encoding for EPSI result in good spatial resolution and spectral separation. Radial acquisition throughout HP signal evolution offers the flexibility for reconstructing spatial maps of mean metabolite distribution and global dynamic time courses of multiple metabolites. Radial EPSI and MBFE acquisitions are well-suited for hyperpolarized (13) C MRI over short and long durations. Advantages to this approach include robustness to nonstationary magnetization, insensitivity to precise acquisition timing, and versatility for reconstructing dynamically acquired spectroscopic data. Copyright © 2013 Wiley Periodicals, Inc.

  6. Lapachol inhibits glycolysis in cancer cells by targeting pyruvate kinase M2.

    Science.gov (United States)

    Shankar Babu, Mani; Mahanta, Sailendra; Lakhter, Alexander J; Hato, Takashi; Paul, Subhankar; Naidu, Samisubbu R

    2018-01-01

    Reliance on aerobic glycolysis is one of the hallmarks of cancer. Although pyruvate kinase M2 (PKM2) is a key mediator of glycolysis in cancer cells, lack of selective agents that target PKM2 remains a challenge in exploiting metabolic pathways for cancer therapy. We report that unlike its structural analog shikonin, a known inhibitor of PKM2, lapachol failed to induce non-apoptotic cell death ferroxitosis in hypoxia. However, melanoma cells treated with lapachol showed a dose-dependent inhibition of glycolysis and a corresponding increase in oxygen consumption. Accordingly, in silico studies revealed a high affinity-binding pocket for lapachol on PKM2 structure. Lapachol inhibited PKM2 activity of purified enzyme as well as in melanoma cell extracts. Blockade of glycolysis by lapachol in melanoma cells led to decreased ATP levels and inhibition of cell proliferation. Furthermore, perturbation of glycolysis in melanoma cells with lapachol sensitized cells to mitochondrial protonophore and promoted apoptosis. These results present lapachol as an inhibitor of PKM2 to interrogate metabolic plasticity in tumor cells.

  7. A Symmetrical Tetramer for S. aureus Pyruvate Carboxylase in Complex with Coenzyme A

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.; Xiang, S; Lasso, G; Gil, D; Valle, M; Tong, L

    2009-01-01

    Pyruvate carboxylase (PC) is a conserved metabolic enzyme with important cellular functions. We report crystallographic and cryo-electron microscopy (EM) studies of Staphylococcus aureus PC (SaPC) in complex with acetyl-CoA, an allosteric activator, and mutagenesis, biochemical, and structural studies of the biotin binding site of its carboxyltransferase (CT) domain. The disease-causing A610T mutation abolishes catalytic activity by blocking biotin binding to the CT active site, and Thr908 might play a catalytic role in the CT reaction. The crystal structure of SaPC in complex with CoA reveals a symmetrical tetramer, with one CoA molecule bound to each monomer, and cryo-EM studies confirm the symmetrical nature of the tetramer. These observations are in sharp contrast to the highly asymmetrical tetramer of Rhizobium etli PC in complex with ethyl-CoA. Our structural information suggests that acetyl-CoA promotes a conformation for the dimer of the biotin carboxylase domain of PC that might be catalytically more competent.

  8. Ethyl Pyruvate Inhibits Retinal Pathogenic Neovascularization by Downregulating HMGB1 Expression

    Directory of Open Access Journals (Sweden)

    Yun Mi Lee

    2013-01-01

    Full Text Available Retinal pathogenic angiogenesis in the eyes is a causative factor in retinopathy of prematurity, diabetic retinopathy, and age-related macular degeneration. This study was designed to examine the pathogenic role of the high-mobility group box-1 (HMGB1 protein and the inhibitory effect of ethyl pyruvate (EP, a well-known antioxidant substance, in retinal pathogenic angiogenesis in mice with oxygen-induced retinopathy (OIR, one of the animal models of proliferative ischemic retinopathy. The OIR mouse model was used for our in vivo studies. The mice were exposed to 75% oxygen from postnatal day 7 (P7 to P11, after which the mice were brought to room air and intraperitoneally injected with EP (50 mg/kg, or 100 mg/kg for five days. At P17, the mice were perfused with fluorescein isothiocyanate-dextran, and flat-mounted retinas were used to measure nonperfused and neovascular tufts. In OIR mice, an intraperitoneal injection of EP reduced the nonperfused retinal area in the treatment group and significantly reduced the retinal neovascular tufts. In addition, EP inhibited the overexpression of HMGB1 in the retinas of OIR mice. These data suggest that EP could serve as an innovative pharmaceutical agent to prevent retinal neovascularization through inhibiting HMGB1 expression.

  9. Pyruvic Oxime Nitrification and Copper and Nickel Resistance by a Cupriavidus pauculus, an Active Heterotrophic Nitrifier-Denitrifier

    OpenAIRE

    Ramirez, Miguel; Obrzydowski, Jennifer; Ayers, Mary; Virparia, Sonia; Wang, Meijing; Stefan, Kurtis; Linchangco, Richard; Castignetti, Domenic

    2014-01-01

    Heterotrophic nitrifiers synthesize nitrogenous gasses when nitrifying ammonium ion. A Cupriavidus pauculus, previously thought an Alcaligenes sp. and noted as an active heterotrophic nitrifier-denitrifier, was examined for its ability to produce nitrogen gas (N2) and nitrous oxide (N2O) while heterotrophically nitrifying the organic substrate pyruvic oxime [CH3–C(NOH)–COOH]. Neither N2 nor N2O were produced. Nucleotide and phylogenetic analyses indicated that the organism is a member of a g...

  10. Enhancing the [13C]bicarbonate signal in cardiac hyperpolarized [1‐13C]pyruvate MRS studies by infusion of glucose, insulin and potassium

    DEFF Research Database (Denmark)

    Lauritzen, Mette Hauge; Laustsen, Christoffer; Butt, Sadia Asghar

    2013-01-01

    the myocardial glucose oxidation in the citric acid cycle, reflected as an increase in the [13C]bicarbonate signal in cardiac hyperpolarized [1‐13C]pyruvate MRS measurements in fasted rats. Two groups of rats were infused with two different doses of GIK and investigated by MRS after injection of hyperpolarized...... [1‐13C]pyruvate. No [13C]bicarbonate signal could be detected in the fasted state. However, a significant increase in the [13C]bicarbonate signal was observed by the infusion of a high dose of GIK. This study demonstrates that a high [13C]bicarbonate signal can be achieved by GIK infusion in fasted...... rats. The increased [13C]bicarbonate signal indicates an increased flux of pyruvate through the pyruvate dehydrogenase enzyme complex and an increase in myocardial glucose oxidation through the citric acid cycle. Copyright © 2013 John Wiley & Sons, Ltd....

  11. Inhibition of Pyruvate Dehydrogenase Kinase 2 Protects Against Hepatic Steatosis Through Modulation of Tricarboxylic Acid Cycle Anaplerosis and Ketogenesis.

    Science.gov (United States)

    Go, Younghoon; Jeong, Ji Yun; Jeoung, Nam Ho; Jeon, Jae-Han; Park, Bo-Yoon; Kang, Hyeon-Ji; Ha, Chae-Myeong; Choi, Young-Keun; Lee, Sun Joo; Ham, Hye Jin; Kim, Byung-Gyu; Park, Keun-Gyu; Park, So Young; Lee, Chul-Ho; Choi, Cheol Soo; Park, Tae-Sik; Lee, W N Paul; Harris, Robert A; Lee, In-Kyu

    2016-10-01

    Hepatic steatosis is associated with increased insulin resistance and tricarboxylic acid (TCA) cycle flux, but decreased ketogenesis and pyruvate dehydrogenase complex (PDC) flux. This study examined whether hepatic PDC activation by inhibition of pyruvate dehydrogenase kinase 2 (PDK2) ameliorates these metabolic abnormalities. Wild-type mice fed a high-fat diet exhibited hepatic steatosis, insulin resistance, and increased levels of pyruvate, TCA cycle intermediates, and malonyl-CoA but reduced ketogenesis and PDC activity due to PDK2 induction. Hepatic PDC activation by PDK2 inhibition attenuated hepatic steatosis, improved hepatic insulin sensitivity, reduced hepatic glucose production, increased capacity for β-oxidation and ketogenesis, and decreased the capacity for lipogenesis. These results were attributed to altered enzymatic capacities and a reduction in TCA anaplerosis that limited the availability of oxaloacetate for the TCA cycle, which promoted ketogenesis. The current study reports that increasing hepatic PDC activity by inhibition of PDK2 ameliorates hepatic steatosis and insulin sensitivity by regulating TCA cycle anaplerosis and ketogenesis. The findings suggest PDK2 is a potential therapeutic target for nonalcoholic fatty liver disease. © 2016 by the American Diabetes Association.

  12. Efficient Production of Pyruvate from DL-Lactate by the Lactate-Utilizing Strain Pseudomonas stutzeri SDM

    Science.gov (United States)

    Gao, Chao; Qiu, Jianhua; Ma, Cuiqing; Xu, Ping

    2012-01-01

    Background The platform chemical lactate is currently produced mainly through the fermentation of sugars presented in biomass. Besides the synthesis of biodegradable polylactate, lactate is also viewed as a feedstock for the green chemistry of the future. Pyruvate, another important platform chemical, can be produced from lactate through biocatalysis. Methodology/Principal Findings It was established that whole cells of Pseudomonas stutzeri SDM catalyze lactate oxidation with lactate-induced NAD-independent lactate dehydrogenases (iLDHs) through the inherent electron transfer chain. Unlike the lactate oxidation processes observed in previous reports, the mechanism underlying lactate oxidation described in the present study excluded the costliness of the cofactor regeneration step and production of the byproduct hydrogen peroxide. Conclusions/Significance Biocatalysis conditions were optimized by using the cheap dl-lactate as the substrate and whole cells of the lactate-utilizing P. stutzeri SDM as catalyst. Under optimal conditions, the biocatalytic process produced pyruvate at a high concentration (48.4 g l−1) and a high yield (98%). The bioconversion system provides a promising alternative for the green production of pyruvate. PMID:22792404

  13. Scanning mutagenesis of the amino acid sequences flanking phosphorylation site 1 of the mitochondrial pyruvate dehydrogenase complex

    Directory of Open Access Journals (Sweden)

    Nagib eAhsan

    2012-07-01

    Full Text Available The mitochondrial pyruvate dehydrogenase complex is regulated by reversible seryl-phosphorylation of the E1α subunit by a dedicated, intrinsic kinase. The phospho-complex is reactivated when dephosphorylated by an intrinsic PP2C-type protein phosphatase. Both the position of the phosphorylated Ser-residue and the sequences of the flanking amino acids are highly conserved. We have used the synthetic peptide-based kinase client assay plus recombinant pyruvate dehydrogenase E1α and E1α-kinase to perform scanning mutagenesis of the residues flanking the site of phosphorylation. Consistent with the results from phylogenetic analysis of the flanking sequences, the direct peptide-based kinase assays tolerated very few changes. Even conservative changes such as Leu, Ile, or Val for Met, or Glu for Asp, gave very marked reductions in phosphorylation. Overall the results indicate that regulation of the mitochondrial pyruvate dehydrogenase complex by reversible phosphorylation is an extreme example of multiple, interdependent instances of co-evolution.

  14. Coordination of manganous ion at the active site of pyruvate, phosphate dikinase: the complex of oxalate with the phosphorylated enzyme

    International Nuclear Information System (INIS)

    Kofron, J.L.; Ash, D.E.; Reed, G.H.

    1988-01-01

    Electron paramagnetic resonance spectroscopy has been used to investigate the structure of the complex of manganous ion with the phosphorylated form of pyruvate, phosphate dikinase (E/sub p/) and the inhibitor oxalate. Oxalate, an analogue of the enolate of pyruvate, is competitive with respect to pyruvate in binding to the phosphorylated form of the enzyme. Superhyperfine coupling between the unpaired electrons of Mn(I) and ligands specifically labeled with 17 O has been used to identify oxygen ligands to Mn(II) in the complex with oxalate and the phosphorylated form of the enzyme. Oxalate binds at the active site as a bidentate chelate with Mn(II). An oxygen from the 3'-N-phosphohistidyl residue of the protein is in the coordination sphere of Mn(II), and at least two water molecules are also bound to Mn(II) in the complex. Oxalate also binds directly to Mn(II) in a complex with nonphosphorylated enzyme. The structure for the E/sub p/-Mn(II)-oxalate complex implies that simultaneous coordination of a phospho group and of the attacking nucleophile to the divalent cation is likely an important factor in catalysis of this phospho-transfer reaction

  15. Identification of a mitochondrial target of thiazolidinedione insulin sensitizers (mTOT--relationship to newly identified mitochondrial pyruvate carrier proteins.

    Directory of Open Access Journals (Sweden)

    Jerry R Colca

    Full Text Available Thiazolidinedione (TZD insulin sensitizers have the potential to effectively treat a number of human diseases, however the currently available agents have dose-limiting side effects that are mediated via activation of the transcription factor PPARγ. We have recently shown PPARγ-independent actions of TZD insulin sensitizers, but the molecular target of these molecules remained to be identified. Here we use a photo-catalyzable drug analog probe and mass spectrometry-based proteomics to identify a previously uncharacterized mitochondrial complex that specifically recognizes TZDs. These studies identify two well-conserved proteins previously known as brain protein 44 (BRP44 and BRP44 Like (BRP44L, which recently have been renamed Mpc2 and Mpc1 to signify their function as a mitochondrial pyruvate carrier complex. Knockdown of Mpc1 or Mpc2 in Drosophila melanogaster or pre-incubation with UK5099, an inhibitor of pyruvate transport, blocks the crosslinking of mitochondrial membranes by the TZD probe. Knockdown of these proteins in Drosophila also led to increased hemolymph glucose and blocked drug action. In isolated brown adipose tissue (BAT cells, MSDC-0602, a PPARγ-sparing TZD, altered the incorporation of (13C-labeled carbon from glucose into acetyl CoA. These results identify Mpc1 and Mpc2 as components of the mitochondrial target of TZDs (mTOT and suggest that understanding the modulation of this complex, which appears to regulate pyruvate entry into the mitochondria, may provide a viable target for insulin sensitizing pharmacology.

  16. Pyruvate into lactate and back: From the Warburg effect to symbiotic energy fuel exchange in cancer cells

    International Nuclear Information System (INIS)

    Feron, Olivier

    2009-01-01

    Tumor cells fuel their metabolism with glucose and glutamine to meet the bioenergetic and biosynthetic demands of proliferation. Hypoxia and oncogenic mutations drive glycolysis, with the pyruvate to lactate conversion being promoted by increased expression of lactate dehydrogenase A and inactivation of pyruvate dehydrogenase. The NAD + pool is consecutively regenerated and supports the high glycolytic flux required to produce anabolic intermediates. Glutaminolysis provides metabolic intermediates such as α-ketoglutarate to feed and thereby maintain the tricarboxylic acid cycle as a biosynthetic hub. Glycolysis and glutaminolysis share the capacity to generate NADPH, from the pentose phosphate pathway and through the malate conversion into pyruvate, respectively. Both pathways ultimately lead to the secretion of lactate. More than a waste product, lactate was recently identified as a major energy fuel in tumors. Lactate produced by hypoxic tumor cells may indeed diffuse and be taken up by oxygenated tumor cells. Preferential utilization of lactate for oxidative metabolism spares glucose which may in turn reach hypoxic tumor cells. Monocarboxylate transporter 1 regulates the entry of lactate into oxidative tumor cells. Its inhibition favors the switch from lactate-fuelled respiration to glycolysis and consecutively kills hypoxic tumor cells from glucose starvation. Combination with radiotherapy renders remaining cells more sensitive to irradiation, emphasizing how interference with tumor cell metabolism may complement current anticancer modalities.

  17. Hepatic Mitochondrial Pyruvate Carrier 1 Is Required for Efficient Regulation of Gluconeogenesis and Whole-Body Glucose Homeostasis.

    Science.gov (United States)

    Gray, Lawrence R; Sultana, Mst Rasheda; Rauckhorst, Adam J; Oonthonpan, Lalita; Tompkins, Sean C; Sharma, Arpit; Fu, Xiaorong; Miao, Ren; Pewa, Alvin D; Brown, Kathryn S; Lane, Erin E; Dohlman, Ashley; Zepeda-Orozco, Diana; Xie, Jianxin; Rutter, Jared; Norris, Andrew W; Cox, James E; Burgess, Shawn C; Potthoff, Matthew J; Taylor, Eric B

    2015-10-06

    Gluconeogenesis is critical for maintenance of euglycemia during fasting. Elevated gluconeogenesis during type 2 diabetes (T2D) contributes to chronic hyperglycemia. Pyruvate is a major gluconeogenic substrate and requires import into the mitochondrial matrix for channeling into gluconeogenesis. Here, we demonstrate that the mitochondrial pyruvate carrier (MPC) comprising the Mpc1 and Mpc2 proteins is required for efficient regulation of hepatic gluconeogenesis. Liver-specific deletion of Mpc1 abolished hepatic MPC activity and markedly decreased pyruvate-driven gluconeogenesis and TCA cycle flux. Loss of MPC activity induced adaptive utilization of glutamine and increased urea cycle activity. Diet-induced obesity increased hepatic MPC expression and activity. Constitutive Mpc1 deletion attenuated the development of hyperglycemia induced by a high-fat diet. Acute, virally mediated Mpc1 deletion after diet-induced obesity decreased hyperglycemia and improved glucose tolerance. We conclude that the MPC is required for efficient regulation of gluconeogenesis and that the MPC contributes to the elevated gluconeogenesis and hyperglycemia in T2D. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Effects of insulin on perfused liver from streptozotocin-diabetic and untreated rats: 13C NMR assay of pyruvate kinase flux

    International Nuclear Information System (INIS)

    Cohen, S.M.

    1987-01-01

    The effects of insulin in vitro on perfused liver from streptozotocin-diabetic rats and their untreated littermates during gluconeogenesis from either [3- 13 C]alanine + ethanol or [2- 13 C]pyruvate + NH 4 Cl + ethanol were studied by 13 C NMR. A 13 C NMR determination of the rate of pyruvate kinase flux under steady-state conditions of active gluconeogenesis was developed; this assay includes a check on the reuse of recycled pyruvate. The preparations studied provided gradations of pyruvate kinase flux within the confines of the assay's requirement of active gluconeogenesis. By this determination, the rate of pyruvate kinase flux was 0.74 +/- 0.04 of the gluconeogenic rate in liver from 24-h-fasted controls; in liver from 12-h fasted controls, relative pyruvate kinase flux increased to 1.0 +/- 0.2. In diabetic liver, this flux was undetectable by the authors NMR method. Insulin's hepatic influence in vitro was greatest in the streptozotocin model of type 1 diabetes: upon treatment of diabetic liver with 7 nM insulin in vitro, a partial reversal of many of the differences noted between diabetic and control liver was demonstrated by 13 C NMR. A major effect of insulin in vitro upon diabetic liver was the induction of a large increase in the rate of pyruvate kinase flux, bringing relative and absolute fluxes up to the levels measured in 24-h-fasted controls. By way of comparison, the effects of ischemia on diabetic liver were studied by 13 C NMR to test whether changes in allosteric effectors under these conditions could also increase pyruvate kinase flux. A large increase in this activity was demonstrated in ischemic diabetic liver

  19. Mount St. Helens Rebirth

    Science.gov (United States)

    2002-01-01

    The catastrophic eruption of Mt. St. Helens 20 years ago today (on May 18, 1980), ranks among the most important natural events of the twentieth century in the United States. Because Mt. St. Helens is in a remote area of the Cascades Mountains, only a few people were killed by the eruption, but property damage and destruction totaled in the billions of dollars. Mount St. Helens is an example of a composite or stratovolcano. These are explosive volcanoes that are generally steep-sided, symmetrical cones built up by the accumulation of debris from previous eruptions and consist of alternating layers of lava flows, volcanic ash and cinder. Some of the most photographed mountains in the world are stratovolcanoes, including Mount Fuji in Japan, Mount Cotopaxi in Ecuador, Mount Hood in Oregon, and Mount Rainier in Washington. The recently erupting Mount Usu on the island of Hokkaido in Japan is also a stratovolcano. Stratovolcanoes are characterized by having plumbing systems that move magma from a chamber deep within the Earth's crust to vents at the surface. The height of Mt. St. Helens was reduced from about 2950 m (9677 ft) to about 2550 m (8364 ft) as a result of the explosive eruption on the morning of May 18. The eruption sent a column of dust and ash upwards more than 25 km into the atmosphere, and shock waves from the blast knocked down almost every tree within 10 km of the central crater. Massive avalanches and mudflows, generated by the near-instantaneous melting of deep snowpacks on the flanks of the mountain, devastated an area more than 20 km to the north and east of the former summit, and rivers choked with all sorts of debris were flooded more than 100 km away. The area of almost total destruction was about 600 sq. km. Ash from the eruption cloud was rapidly blown to the northeast and east producing lightning which started many small forest fires. An erie darkness caused by the cloud enveloped the landscape more than 200 km from the blast area, and ash

  20. Cardiac-Specific Deletion of Pyruvate Dehydrogenase Impairs Glucose Oxidation Rates and Induces Diastolic Dysfunction.

    Science.gov (United States)

    Gopal, Keshav; Almutairi, Malak; Al Batran, Rami; Eaton, Farah; Gandhi, Manoj; Ussher, John Reyes

    2018-01-01

    Obesity and type 2 diabetes (T2D) increase the risk for cardiomyopathy, which is the presence of ventricular dysfunction in the absence of underlying coronary artery disease and/or hypertension. As myocardial energy metabolism is altered during obesity/T2D (increased fatty acid oxidation and decreased glucose oxidation), we hypothesized that restricting myocardial glucose oxidation in lean mice devoid of the perturbed metabolic milieu observed in obesity/T2D would produce a cardiomyopathy phenotype, characterized via diastolic dysfunction. We tested our hypothesis via producing mice with a cardiac-specific gene knockout for pyruvate dehydrogenase (PDH, gene name Pdha1 ), the rate-limiting enzyme for glucose oxidation. Cardiac-specific Pdha1 deficient ( Pdha1 Cardiac-/- ) mice were generated via crossing a tamoxifen-inducible Cre expressing mouse under the control of the alpha-myosin heavy chain (αMHC-MerCreMer) promoter with a floxed Pdha1 mouse. Energy metabolism and cardiac function were assessed via isolated working heart perfusions and ultrasound echocardiography, respectively. Tamoxifen administration produced an ~85% reduction in PDH protein expression in Pdha1 Cardiac-/- mice versus their control littermates, which resulted in a marked reduction in myocardial glucose oxidation and a corresponding increase in palmitate oxidation. This myocardial metabolism profile did not impair systolic function in Pdha1 Cardiac-/- mice, which had comparable left ventricular ejection fractions and fractional shortenings as their αMHC-MerCreMer control littermates, but did produce diastolic dysfunction as seen via the reduced mitral E/A ratio. Therefore, it does appear that forced restriction of glucose oxidation in the hearts of Pdha1 Cardiac-/- mice is sufficient to produce a cardiomyopathy-like phenotype, independent of the perturbed metabolic milieu observed in obesity and/or T2D.

  1. The effect of ethyl pyruvate on oxidative stress in intestine and bacterial translocation after thermal injury.

    Science.gov (United States)

    Karabeyoğlu, Melih; Unal, Bülent; Bozkurt, Betül; Dolapçi, Iştar; Bilgihan, Ayşe; Karabeyoğlu, Işil; Cengiz, Omer

    2008-01-01

    Thermal injury causes a breakdown in the intestinal mucosal barrier due to ischemia reperfusion injury, which can induce bacterial translocation (BT), sepsis, and multiple organ failure in burn patients. The aim of this study was to investigate the effect of ethyl pyruvate (EP) on intestinal oxidant damage and BT in burn injury. Thirty-two rats were randomly divided into four groups. The sham group was exposed to 21 degrees C water and injected intraperitoneal with saline (1 mL/100 g). The sham + EP group received EP (40 mg/kg) intraperitoneally 6 h after the sham procedure. The burn group was exposed to thermal injury and given intraperitoneal saline injection (1 mL/100 g). The burn + EP group received EP (40 mg/kg) intraperitoneally 6 h after thermal injury. Twenty-four hours later, tissue samples were obtained from mesenteric lymph nodes, spleen, and liver for microbiological analysis and ileum samples were harvested for biochemical analysis. Thermal injury caused severe BT in burn group. EP supplementation decreased BT in mesenteric lymph nodes and spleen in the burn + EP group compared with the burn group (P < 0.05). Also, burn caused BT in liver, but this finding was not statistically significant among all groups. Thermal injury caused a statistically significant increase in malondialdehyde and myeloperoxidase levels, and EP prevented this effects in the burn + EP group compared with the burn group (P < 0.05). Our data suggested that EP can inhibit the BT and myeloperoxidase and malondialdehyde production in intestine following thermal injury, suggesting anti-inflammatory and anti-oxidant properties of EP.

  2. Physical exercise reduces pyruvate carboxylase (PCB) and contributes to hyperglycemia reduction in obese mice.

    Science.gov (United States)

    Muñoz, Vitor Rosetto; Gaspar, Rafael Calais; Crisol, Barbara Moreira; Formigari, Guilherme Pedron; Sant'Ana, Marcella Ramos; Botezelli, José Diego; Gaspar, Rodrigo Stellzer; da Silva, Adelino S R; Cintra, Dennys Esper; de Moura, Leandro Pereira; Ropelle, Eduardo Rochete; Pauli, José Rodrigo

    2017-07-14

    The present study evaluated the effects of exercise training on pyruvate carboxylase protein (PCB) levels in hepatic tissue and glucose homeostasis control in obese mice. Swiss mice were distributed into three groups: control mice (CTL), fed a standard rodent chow; diet-induced obesity (DIO), fed an obesity-inducing diet; and a third group, which also received an obesity-inducing diet, but was subjected to an exercise training protocol (DIO + EXE). Protocol training was carried out for 1 h/d, 5 d/wk, for 8 weeks, performed at an intensity of 60% of exhaustion velocity. An insulin tolerance test (ITT) was performed in the last experimental week. Twenty-four hours after the last physical exercise session, the animals were euthanized and the liver was harvested for molecular analysis. Firstly, DIO mice showed increased epididymal fat and serum glucose and these results were accompanied by increased PCB and decreased p-Akt in hepatic tissue. On the other hand, physical exercise was able to increase the performance of the mice and attenuate PCB levels and hyperglycemia in DIO + EXE mice. The above findings show that physical exercise seems to be able to regulate hyperglycemia in obese mice, suggesting the participation of PCB, which was enhanced in the obese condition and attenuated after a treadmill running protocol. This is the first study to be aimed at the role of exercise training in hepatic PCB levels, which may be a novel mechanism that can collaborate to reduce the development of hyperglycemia and type 2 diabetes in DIO mice.

  3. Organism-adapted specificity of the allosteric regulation of pyruvate kinase in lactic acid bacteria.

    Directory of Open Access Journals (Sweden)

    Nadine Veith

    Full Text Available Pyruvate kinase (PYK is a critical allosterically regulated enzyme that links glycolysis, the primary energy metabolism, to cellular metabolism. Lactic acid bacteria rely almost exclusively on glycolysis for their energy production under anaerobic conditions, which reinforces the key role of PYK in their metabolism. These organisms are closely related, but have adapted to a huge variety of native environments. They include food-fermenting organisms, important symbionts in the human gut, and antibiotic-resistant pathogens. In contrast to the rather conserved inhibition of PYK by inorganic phosphate, the activation of PYK shows high variability in the type of activating compound between different lactic acid bacteria. System-wide comparative studies of the metabolism of lactic acid bacteria are required to understand the reasons for the diversity of these closely related microorganisms. These require knowledge of the identities of the enzyme modifiers. Here, we predict potential allosteric activators of PYKs from three lactic acid bacteria which are adapted to different native environments. We used protein structure-based molecular modeling and enzyme kinetic modeling to predict and validate potential activators of PYK. Specifically, we compared the electrostatic potential and the binding of phosphate moieties at the allosteric binding sites, and predicted potential allosteric activators by docking. We then made a kinetic model of Lactococcus lactis PYK to relate the activator predictions to the intracellular sugar-phosphate conditions in lactic acid bacteria. This strategy enabled us to predict fructose 1,6-bisphosphate as the sole activator of the Enterococcus faecalis PYK, and to predict that the PYKs from Streptococcus pyogenes and Lactobacillus plantarum show weaker specificity for their allosteric activators, while still having fructose 1,6-bisphosphate play the main activator role in vivo. These differences in the specificity of allosteric

  4. Significant accumulation of C(4)-specific pyruvate, orthophosphate dikinase in a C(3) plant, rice.

    Science.gov (United States)

    Fukayama, H; Tsuchida, H; Agarie, S; Nomura, M; Onodera, H; Ono, K; Lee, B H; Hirose, S; Toki, S; Ku, M S; Makino, A; Matsuoka, M; Miyao, M

    2001-11-01

    The C(4)-Pdk gene encoding the C(4) enzyme pyruvate, orthophosphate dikinase (PPDK) of maize (Zea mays cv Golden Cross Bantam) was introduced into the C(3) plant, rice (Oryza sativa cv Kitaake). When the intact maize C(4)-Pdk gene, containing its own promoter and terminator sequences and exon/intron structure, was introduced, the PPDK activity in the leaves of some transgenic lines was greatly increased, in one line reaching 40-fold over that of wild-type plants. In a homozygous line, the PPDK protein accounted for 35% of total leaf-soluble protein or 16% of total leaf nitrogen. In contrast, introduction of a chimeric gene containing the full-length cDNA of the maize PPDK fused to the maize C(4)-Pdk promoter or the rice Cab promoter only increased PPDK activity and protein level slightly. These observations suggest that the intron(s) or the terminator sequence of the maize gene, or a combination of both, is necessary for high-level expression. In maize and transgenic rice plants carrying the intact maize gene, the level of transcript in the leaves per copy of the maize C(4)-Pdk gene was comparable, and the maize gene was expressed in a similar organ-specific manner. These results suggest that the maize C(4)-Pdk gene behaves in a quantitatively and qualitatively similar way in maize and transgenic rice plants. The activity of the maize PPDK protein expressed in rice leaves was light/dark regulated as it is in maize. This is the first reported evidence for the presence of an endogenous PPDK regulatory protein in a C(3) plant.

  5. miR-122 targets pyruvate kinase M2 and affects metabolism of hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Angela M Liu

    Full Text Available In contrast to normal differentiated cells that depend on mitochondrial oxidative phosphorylation for energy production, cancer cells have evolved to utilize aerobic glycolysis (Warburg's effect, with benefit of providing intermediates for biomass production. MicroRNA-122 (miR-122 is highly expressed in normal liver tissue regulating a wide variety of biological processes including cellular metabolism, but is reduced in hepatocellular carcinoma (HCC. Overexpression of miR-122 was shown to inhibit cancer cell proliferation, metastasis, and increase chemosensitivity, but its functions in cancer metabolism remains unknown. The present study aims to identify the miR-122 targeted genes and to investigate the associated regulatory mechanisms in HCC metabolism. We found the ectopic overexpression of miR-122 affected metabolic activities of HCC cells, evidenced by the reduced lactate production and increased oxygen consumption. Integrated gene expression analysis in a cohort of 94 HCC tissues revealed miR-122 level tightly associated with a battery of glycolytic genes, in which pyruvate kinase (PK gene showed the strongest anti-correlation coefficient (Pearson r = -0.6938, p = <0.0001. In addition, reduced PK level was significantly associated with poor clinical outcomes of HCC patients. We found isoform M2 (PKM2 is the dominant form highly expressed in HCC and is a direct target of miR-122, as overexpression of miR-122 reduced both the mRNA and protein levels of PKM2, whereas PKM2 re-expression abrogated the miR-122-mediated glycolytic activities. The present study demonstrated the regulatory role of miR-122 on PKM2 in HCC, having an implication of therapeutic intervention targeting cancer metabolic pathways.

  6. Pyruvate formate lyase acts as a formate supplier for metabolic processes during anaerobiosis in Staphylococcus aureus.

    Science.gov (United States)

    Leibig, Martina; Liebeke, Manuel; Mader, Diana; Lalk, Michael; Peschel, Andreas; Götz, Friedrich

    2011-02-01

    Previous studies demonstrated an upregulation of pyruvate formate lyase (Pfl) and NAD-dependent formate dehydrogenase (Fdh) in Staphylococcus aureus biofilms. To investigate their physiological role, we constructed fdh and pfl deletion mutants (Δfdh and Δpfl). Although formate dehydrogenase activity in the fdh mutant was lost, it showed little phenotypic alterations under oxygen-limited conditions. In contrast, the pfl mutant displayed pleiotropic effects and revealed the importance of formate production for anabolic metabolism. In the pfl mutant, no formate was produced, glucose consumption was delayed, and ethanol production was decreased, whereas acetate and lactate production were unaffected. All metabolic alterations could be restored by addition of formate or complementation of the Δpfl mutant. In compensation reactions, serine and threonine were consumed better by the Δpfl mutant than by the wild type, suggesting that their catabolism contributes to the refilling of formyl-tetrahydrofolate, which acts as a donor of formyl groups in, e.g., purine and protein biosynthesis. This notion was supported by reduced production of formylated peptides by the Δpfl mutant compared to that of the parental strain, as demonstrated by weaker formyl-peptide receptor 1 (FPR1)-mediated activation of leukocytes with the mutant. FPR1 stimulation could also be restored either by addition of formate or by complementation of the mutation. Furthermore, arginine consumption and arc operon transcription were increased in the Δpfl mutant. Unlike what occurred with the investigated anaerobic conditions, a biofilm is distinguished by nutrient, oxygen, and pH gradients, and we thus assume that Pfl plays a significant role in the anaerobic layer of a biofilm. Fdh might be critical in (micro)aerobic layers, as formate oxidation is correlated with the generation of NADH/H(+), whose regeneration requires respiration.

  7. Attenuation of Methotrexate-Induced Embryotoxicity and Oxidative Stress by Ethyl Pyruvate

    Directory of Open Access Journals (Sweden)

    Najafi Gholamreza

    2016-07-01

    Full Text Available Background Methotrexate (MTX, as an anti-folate agent, is widely used in the treatment of rheumatic disorders and malignant tumors, however it damages reproductive sys- tem in mice. The aim of this research was to study the effects of ethyl pyruvate (EP on embryo development and oxidative stress changes in the testis of mice treated with MTX. Materials and Methods In this experimental study, thirty-two adult male Naval Medical Research Institute mice, with average weight of 26 ± 2 g, were divided into four groups. The first group (control received distilled water (0.1 ml/mice/day, while the second group was intraperitoneally (IP treated with 20 mg/kg MTX once per week. The third group was IP treated with 40 mg/kg/day EP, and the fourth group was IP treated with both 20 mg/kg MTX and 40 mg/kg/day EP for 30 days. At the end of treatment fertilization rate and embryonic development were evaluated. Differences between these groups were assessed by ANOVA using the SPSS software package for Windows with a Tukey-Kramer multiple post-hoc comparison test. Results MTX treatment caused significant (P<0.05 increase in malondialdehyde (MDA and reduced catalase (CAT, as well as leading to in vitro fertilization (IVF and embryonic development. The improved effects of EP on the IVF were determined by the reduced level of MDA (index of oxidative stress and significant increased level of CAT (a key antioxidant. We observed significant increase in fertilization rate and embryonic development in the treated group with both MTX and EP. Conclusion It is suggested that EP can be useful in ameliorating testicular damages and embryotoxicity induced by MTX. These effects could be attributed to its antioxidant properties.

  8. Communication from ST Group

    CERN Document Server

    TS Department

    2008-01-01

    In order to prepare the organization of the Open Days, please note that FM Group will not able to take into account either specific requests for waste collection from 2nd to 6th of April, either removal or PC transport requests between the 31st and the 11th of March. We kindly ask you to plan the collection of any type of waste and the urgent transport of office furniture or PC before the 31st of March. Waste collection requests shall be formulated contacting FM Support at 77777 or at the email address mailto:Fm.Support@cern.ch; removal of office furniture or PC transport requests must be made using the EDH ‘Transport request’ form selecting the "Removals" or the "PC transport" category from the drop-down menu. For any question concerning the waste sorting, please consult the following web address: http://dechets-waste.web.cern.ch/dechets-waste/. Thank you for your understanding and collaboration. TS/FM Group

  9. Mount St. Helens Flyover

    Science.gov (United States)

    2002-01-01

    This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image of Mt. St. Helens volcano in Washington State was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER's 3-D stereo bands. The color was computer enhanced to create a 'natural' color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief. Landsat7 aquired an image of Mt. St. Helens on August 22, 1999. Image and animation courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  10. The contribution of two isozymes to the pyruvate kinase activity of Vibrio cholerae: One K+-dependent constitutively active and another K+-independent with essential allosteric activation.

    Science.gov (United States)

    Guerrero-Mendiola, Carlos; García-Trejo, José J; Encalada, Rusely; Saavedra, Emma; Ramírez-Silva, Leticia

    2017-01-01

    In a previous phylogenetic study of the family of pyruvate kinase EC (2.7.1.40), a cluster with Glu117 and another with Lys117 were found (numbered according to the rabbit muscle enzyme). The sequences with Glu117 have been found to be K+-dependent, whereas those with Lys117 were K+-independent. Interestingly, only γ-proteobacteria exhibit sequences in both branches of the tree. In this context, it was explored whether these phylogenetically distinct pyruvate kinases were both expressed and contribute to the pyruvate kinase activity in Vibrio cholerae. The main findings of this work showed that the isozyme with Glu117 is an active K+-dependent enzyme. At the same substrate concentration, its Vmax in the absence of fructose 1,6 bisphosphate was 80% of that with its effector. This result is in accordance with the non-essential activation described by allosteric ligands for most pyruvate kinases. In contrast, the pyruvate kinase with Lys117 was a K+-independent enzyme displaying an allosteric activation by ribose 5-phosphate. At the same substrate concentration, its activity without the effector was 0.5% of the one obtained in the presence of ribose 5-phosphate, indicating that this sugar monophosphate is a strong activator of this enzyme. This absolute allosteric dependence is a novel feature of pyruvate kinase activity. Interestingly, in the K+-independent enzyme, Mn2+ may "mimic" the allosteric effect of Rib 5-P. Despite their different allosteric behavior, both isozymes display a rapid equilibrium random order kinetic mechanism. The intracellular concentrations of fructose 1,6-bisphosphate and ribose 5-phosphate in Vibrio cholerae have been experimentally verified to be sufficient to induce maximal activation of both enzymes. In addition, Western blot analysis indicated that both enzymes were co-expressed. Therefore, it is concluded that VcIPK and VcIIPK contribute to the activity of pyruvate kinase in this γ-proteobacterium.

  11. StUbEx

    DEFF Research Database (Denmark)

    Akimov, Vyacheslav; Henningsen, Jeanette; Hallenborg, Philip

    2014-01-01

    Post-translational modification of proteins with the small polypeptide ubiquitin plays a pivotal role in many cellular processes, altering protein lifespan, location, and function and regulating protein-protein interactions. Ubiquitination exerts its diverse functions through complex mechanisms...... by formation of different polymeric chains and subsequent recognition of the ubiquitin signal by specific protein interaction domains. Despite some recent advances in the analytical tools for the analysis of ubiquitination by mass spectrometry, there is still a need for additional strategies suitable...... for investigation of cellular ubiquitination at the proteome level. Here, we present a stable tagged ubiquitin exchange (StUbEx) cellular system in which endogenous ubiquitin is replaced with an epitope-tagged version, thereby allowing specific and efficient affinity purification of ubiquitinated proteins...

  12. Mt. St. Helens

    Science.gov (United States)

    2001-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1 Movie This 3-D anaglyph image of Mt. St. Helens volcano combines the nadir-looking and back-looking band 3 images of ASTER. To view the image in stereo, you will need blue-red glasses. Make sure to look through the red lens with your left eye. Figure 1: This ASTER image of Mt. St. Helens volcano in Washington was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The image is centered at 46.2 degrees north latitude, 122.2 degrees west longitude. Movie: The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER's 3-D stereo bands. The color was computer enhanced to create a natural color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  13. GABAergic transmission and chloride equilibrium potential are not modulated by pyruvate in the developing optic tectum of Xenopus laevis tadpoles.

    Directory of Open Access Journals (Sweden)

    Arseny S Khakhalin

    Full Text Available In the developing mammalian brain, gamma-aminobutyric acid (GABA is thought to play an excitatory rather than an inhibitory role due to high levels of intracellular Cl(- in immature neurons. This idea, however, has been questioned by recent studies which suggest that glucose-based artificial cerebrospinal fluid (ACSF may be inadequate for experiments on immature and developing brains. These studies suggest that immature neurons may require alternative energy sources, such as lactate or pyruvate. Lack of these other energy sources is thought to result in artificially high intracellular Cl(- concentrations, and therefore a more depolarized GABA receptor (GABAR reversal potential. Since glucose metabolism can vary widely among different species, it is important to test the effects of these alternative energy sources on different experimental preparations. We tested whether pyruvate affects GABAergic transmission in isolated brains of developing wild type Xenopus tadpoles in vitro by recording the responsiveness of tectal neurons to optic nerve stimulation, and by measuring currents evoked by local GABA application in a gramicidin perforated patch configuration. We found that, in contrast with previously reported results, the reversal potential for GABAR-mediated currents does not change significantly between developmental stages 45 and 49. Partial substitution of glucose by pyruvate had only minor effects on both the GABA reversal potential, and the responsiveness of tectal neurons at stages 45 and 49. Total depletion of energy sources from the ACSF did not affect neural responsiveness. We also report a strong spatial gradient in GABA reversal potential, with immature cells adjacent to the lateral and caudal proliferative zones having more positive reversal potentials. We conclude that in this experimental preparation standard glucose-based ACSF is an appropriate extracellular media for in vitro experiments.

  14. Molecular and functional characterization of two pyruvate decarboxylase genes, PDC1 and PDC5, in the thermotolerant yeast Kluyveromyces marxianus.

    Science.gov (United States)

    Choo, Jin Ho; Han, Changpyo; Lee, Dong Wook; Sim, Gyu Hun; Moon, Hye Yun; Kim, Jae-Young; Song, Ji-Yoon; Kang, Hyun Ah

    2018-04-01

    Pyruvate decarboxylase (Pdc) is a cytosolic enzyme located at the branch point between fermentative and respiratory sugar catabolism. Here, we identified and functionally characterized KmPDC1 and KmPDC5 encoding two homologs of Pdc in the thermotolerant yeast Kluyveromyces marxianus KCTC 17555. Despite the conservation of important Pdc domains, a few amino acid sequences essential for enzymatic activity are not conserved in KmPdc5p. Deletion of KmPDC1 alone eliminated most of Pdc activity, but the growth of the Kmpdc1Δ strain on glucose was comparable to that of the wild type (WT) strain under aerobic conditions. In contrast to the WT, Kmpdc1Δ could not grow on glucose under oxygen-limited conditions. The KmPDC5 deletion did not generate any apparent change in Pdc activity or growth patterns under several tested conditions. Whereas the expression of KmPDC1 was enhanced by glucose, the basic expression levels of KmPDC5 were very low, without a detectable difference between glucose and nonfermentable carbon sources. Moreover, KmPDC5 overexpression was unable to complement the growth defect of Kmpdc1Δ in the presence of antimycin A, and the purified recombinant KmPdc5p was inactive in Pdc activity assay, supporting the notion that KmPdc5p may lack Pdc enzymatic activity. Notably, compared to the WT, Kmpdc1Δ single and Kmpdc1Δpdc5Δ double mutants produced significantly less glycerol, acetate, and ethanol while accumulating pyruvate. Altogether, our data indicate that a single deletion of KmPDC1 is sufficient in Crabtree-negative K. marxianus strains to generate a starting host strain for engineering of production of high-value biomaterials derived from pyruvate without byproduct formation.

  15. Cloning of affecting pyruvate decarboxylase gene in the production bioethanol of agricultural waste in the E.coli bacteria

    Directory of Open Access Journals (Sweden)

    Masome Zeinali

    2016-09-01

    Full Text Available Introduction: Ethanol made by a biomass is one of the useful strategies in terms of economic and environmental and as a clean and safe energy to replace fossil fuels considered and examined. Materials and methods: In this study, key enzyme in the production of ethanol (Pyruvate decarboxylase from Zymomonas mobilis bacteria was isolated and cloned at E. coli bacteria by freeze and thaw method. For gene cloning, we used specific primers of pdc and PCR reaction and then pdc gene isolated and pET 28a plasmid double digested with (Sal I and Xho I enzymes. Digestion Products were ligated by T4 DNA ligase in 16 °C for 16 hours. Results: Results of bacteria culture showed that a few colonies containing pET 28a plasmid could grow. Result of colony pcr of pdc gene with specific primers revealed 1700 bp bands in 1% agarose gel electrophoresis. The results of PCR with T7 promotor forward primer and pdc revers primer have proved the accurate direction of integration of pdc gene into plasmid and revealed 1885 bp band. Double digestion of recombinant plasmid with SalI and XhoI enzymes revealed same bands. Finally, RT showed the expected band of 1700 bp that implies the desired gene expression in the samples. Discussion and conclusion: Due to the increased production of ethanol via pyruvate decarboxylase gene cloning in expression plasmids with a strong promoter upstream of the cloning site can conclude that, pyruvate decarboxylase cloning as a key gene would be useful and according to beneficial properties of E. coli bacteria, transfering the gene to bacteria appears to be reasonable.

  16. Enhanced pyruvate dehydrogenase activity improves cardiac outcomes in a murine model of cardiac arrest.

    Directory of Open Access Journals (Sweden)

    Lin Piao

    Full Text Available Post-ischemic changes in cellular metabolism alter myocardial and neurological function. Pyruvate dehydrogenase (PDH, the limiting step in mitochondrial glucose oxidation, is inhibited by increased expression of PDH kinase (PDK during ischemia/reperfusion injury. This results in decreased utilization of glucose to generate cellular ATP. Post-cardiac arrest (CA hypothermia improves outcomes and alters metabolism, but its influence on PDH and PDK activity following CA are unknown. We hypothesized that therapeutic hypothermia (TH following CA is associated with the inhibition of PDK activity and increased PDH activity. We further hypothesized that an inhibitor of PDK activity, dichloroacetate (DCA, would improve PDH activity and post-CA outcomes.Anesthetized and ventilated adult female C57BL/6 wild-type mice underwent a 12-minute KCl-induced CA followed by cardiopulmonary resuscitation. Compared to normothermic (37°C CA controls, administering TH (30°C improved overall survival (72-hour survival rate: 62.5% vs. 28.6%, P<0.001, post-resuscitation myocardial function (ejection fraction: 50.9±3.1% vs. 27.2±2.0%, P<0.001; aorta systolic pressure: 132.7±7.3 vs. 72.3±3.0 mmHg, P<0.001, and neurological scores at 72-hour post CA (9.5±1.3 vs. 5.4±1.3, P<0.05. In both heart and brain, CA increased lactate concentrations (1.9-fold and 3.1-fold increase, respectively, P<0.01, decreased PDH enzyme activity (24% and 50% reduction, respectively, P<0.01, and increased PDK protein expressions (1.2-fold and 1.9-fold, respectively, P<0.01. In contrast, post-CA treatment with TH normalized lactate concentrations (P<0.01 and P<0.05 and PDK expressions (P<0.001 and P<0.05, while increasing PDH activity (P<0.01 and P<0.01 in both the heart and brain. Additionally, treatment with DCA (0.2 mg/g body weight 30 min prior to CA improved both myocardial hemodynamics 2 hours post-CA (aortic systolic pressure: 123±3 vs. 96±4 mmHg, P<0.001 and 72-hour survival rates

  17. Mechanisms of pyruvate kinase M2 isoform inhibits cell motility in hepatocellular carcinoma cells.

    Science.gov (United States)

    Chen, Yan-Ling; Song, Jun-Jiao; Chen, Xiao-Chun; Xu, Wei; Zhi, Qiang; Liu, Yun-Peng; Xu, Hong-Zhi; Pan, Jin-Shui; Ren, Jian-Lin; Guleng, Bayasi

    2015-08-14

    To investigate biological mechanisms underlying pyruvate kinase M2 isoform (PKM2) regulation of cell migration and invasion in hepatocellular carcinoma cells. HepG2 and Huh-7 hepatocellular carcinoma cell lines were stably transfected and cultured in DMEM (HyClone, Logan, UT, United States). To investigate the effects of PKM2 on cellular proliferation, hepatocellular carcinoma cells were subjected to the Cell Counting Kit-8 (Dojindo, Kamimashiki-gun, Kumamoto, Japan). And investigate the effects of PKM2 on cell signal pathway related with migration and invasion, Western immunoblotting were used to find out the differential proteins. All the antibody used was purchaseed from Cell Signal Technology. In order to explore cell motility used Transwell invasion and wound healing assays. The transwell plate with 0.5 mg/mL collagen type I (BD Bioscience, San Jose, CA)-coated filters. The wound-healing assay was performed in 6-well plates. Total RNA was extracted using TRIzol reagent (Invitrogen, CA, United States) and then reverse transcription was conducted. Quantitative reverse transcription-polymerase chain reaction (PCR) analysis was performed with the ABI 7500 real-time PCR system (Applied Biosystems). We further use digital gene expression tag profiling and identification of differentially expressed genes. The cells seeded in four 96-well plates were measured OD450 by conducted Cell Counting Kit-8. From this conduction we observed that both HepG2 and Huh-7 hepatocellular carcinoma cells with silenced PKM2 turn on a proliferate inhibition; however, cell migration and invasion were enhanced compared with the control upon stimulation with epidermal growth factor (EGF). Our results indicate that the knockdown of PKM2 decreased the expression of E-cadherin and enhanced the activity of the EGF/EGFR signaling pathway, furthermore up-regulate the subsequent signal molecular the PLCγ1 and extracellular signal-regulated kinase 1/2 expression in the hepatocellular carcinoma

  18. Coupling between the blood lactate-to-pyruvate ratio and MCA Vmean at the onset of exercise in humans

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Madsen, Camilla A; Nielsen, Henning B

    2009-01-01

    Activation-induced increase in cerebral blood flow is coupled to enhanced metabolic activity, maybe with brain tissue redox state and oxygen tension as key modulators. To evaluate this hypothesis at the onset of exercise in humans, blood was sampled at 0.1 to 0.2 Hz from the radial artery and right...... internal jugular vein, while middle cerebral artery mean flow velocity (MCA V(mean)) was recorded. Both the arterial and venous lactate-to-pyruvate ratio increased after 10 s (P capillary...... state and oxygenation as potential modulators of an increase in cerebral blood flow at the onset of exercise....

  19. Measuring Mitochondrial Metabolism in Rat Brain in vivo using MR Spectroscopy of Hyperpolarized [2-13C]Pyruvate

    OpenAIRE

    Park, Jae Mo; Josan, Sonal; Grafendorfer, Thomas; Yen, Yi-Fen; Hurd, Ralph E.; Spielman, Daniel M.; Mayer, Dirk

    2013-01-01

    Hyperpolarized [1-13C]pyruvate (Pyr) has been used to assess metabolism in healthy and diseased states, focusing on downstream labeling of lactate (Lac), bicarbonate (Bic), and alanine. Whereas hyperpolarized [2-13C]Pyr, which retains the labeled carbon when Pyr is converted to acetyl-coenzyme A (acetyl-CoA), has been successfully used to assess mitochondrial metabolism in the heart, the application of [2-13C]Pyr in the study of brain metabolism has been limited to date, with Lac being the on...

  20. Simultaneous hyperpolarized 13C-pyruvate MRI and 18F-FDG-PET in cancer (hyperPET)

    DEFF Research Database (Denmark)

    Gutte, Henrik; Hansen, Adam E.; Henriksen, Sarah T.

    2015-01-01

    corresponded to high 18F-FDG uptake on PET. This is in agreement with the fact that glycolysis and production of lactate are increased in tumor cells compared to normal cells. Yet, most interestingly, also in the muscle of the forepaw of the dog high 18F-FDG uptake was observed. This was due to activity...... between causes of increased glucose uptake. We propose that this new concept of simultaneous hyperpolarized 13C-pyruvate MRSI and PET may be highly valuable for image-based non-invasive phenotyping of tumors. This methods may be useful for treatment planning and therapy monitoring....

  1. Brain hypoxanthine concentration correlates to lactate/pyruvate ratio but not intracranial pressure in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, Peter Nissen; Hauerberg, John; Jørgensen, Linda

    2010-01-01

    The pathogenesis of cerebral edema in acute liver failure is suggested, in in vitro and animal studies, to involve a compromised oxidative metabolism with a decrease in cerebral ATP levels and an increase in purine concentrations. In this study we hypothesize that the cerebral concentrations...... of hypoxanthine, inosine, and lactate/pyruvate (LP) ratio are increased and correlated in patients with acute liver failure. Furthermore, we expect the purines and L/P ratio to correlate with intracranial pressure (ICP) (positively), and cerebral perfusion pressure (CPP) (negatively)....

  2. Functional pyruvate formate lyase pathway expressed with two different electron donors in Saccharomyces cerevisiae at aerobic growth

    DEFF Research Database (Denmark)

    Zhang, Yiming; Dai, Zongjie; Krivoruchko, Anastasia

    2015-01-01

    Pyruvate formate lyase (PFL) is characterized as an enzyme functional at anaerobic conditions, since the radical in the enzyme's active form is sensitive to oxygen. In this study, PFL and its activating enzyme from Escherichia coli were expressed in a Saccharomyces cerevisiae strain lacking...... of either of these electron donors had a positive effect on growth under aerobic conditions, indicating increased activity of PFL. The positive effect on growth was manifested as a higher final biomass concentration and a significant increase in transcription of formate dehydrogenases. Among the two...

  3. Growth of Campylobacter incubated aerobically in fumarate-pyruvate media or media supplemented with dairy, meat, or soy extracts and peptones.

    Science.gov (United States)

    Hinton, Arthur

    2016-09-01

    The ability of Campylobacter to grow aerobically in media supplemented with fumarate-pyruvate or with dairy, meat, or soy extracts or peptones was examined. Optical densities (OD) of Campylobacter cultured in basal media, media supplemented with fumarate-pyruvate or with 1.0, 2.5, 5.0, or 7.5% beef extract was measured. Growth was also compared in media supplemented with other extracts or peptones. Finally, cfu/mL of Campylobacter recovered from basal media or media supplemented with fumarate-pyruvate, casamino acids, beef extract, soytone, or beef extract and soytone was determined. Results indicated that OD of cultures grown in media supplemented with fumarate-pyruvate or with 5.0 or 7.5% beef extract were higher than OD of isolates grown in basal media or media supplemented with lower concentrations of beef extract. Highest OD were produced by isolates grown in media supplemented with beef extract, peptone from meat, polypeptone, proteose peptone, or soytone. Also, more cfu/mL were recovered from media with fumarate-pyruvate, beef extract, soytone, or beef extract-soytone than from basal media or media with casamino acids. Findings indicate that media supplemented with organic acids, vitamins, and minerals and media supplemented with extracts or peptones containing these metabolites can support aerobic growth of Campylobacter. Published by Elsevier Ltd.

  4. Reverse reaction of malic enzyme for HCO3- fixation into pyruvic acid to synthesize L-malic acid with enzymatic coenzyme regeneration.

    Science.gov (United States)

    Ohno, Yoko; Nakamori, Toshihiko; Zheng, Haitao; Suye, Shin-ichiro

    2008-05-01

    Malic enzyme [L-malate: NAD(P)(+) oxidoreductase (EC 1.1.1.39)] catalyzes the oxidative decarboxylation of L-malic acid to produce pyruvic acid using the oxidized form of NAD(P) (NAD(P)(+)). We used a reverse reaction of the malic enzyme of Pseudomonas diminuta IFO 13182 for HCO(3)(-) fixation into pyruvic acid to produce L-malic acid with coenzyme (NADH) generation. Glucose-6-phosphate dehydrogenase (EC1.1.1.49) of Leuconostoc mesenteroides was suitable for coenzyme regeneration. Optimum conditions for the carboxylation of pyruvic acid were examined, including pyruvic acid, NAD(+), and both malic enzyme and glucose-6-phosphate dehydrogenase concentrations. Under optimal conditions, the ratio of HCO(3)(-) and pyruvic acid to malic acid was about 38% after 24 h of incubation at 30 degrees C, and the concentration of the accumulated L-malic acid in the reaction mixture was 38 mM. The malic enzyme reverse reaction was also carried out by the conjugated redox enzyme reaction with water-soluble polymer-bound NAD(+).

  5. Divisions-ST Formation

    CERN Document Server

    Henny, L

    2001-01-01

    Au CERN la formation est une partie intégrante des activités de l'Organisation. Mentionnée dans le Statut du Personnel depuis l'origine, elle figure au Règlement depuis 1981 et est largement explicitée dans la Circulaire Administrative N° 16. L'organe réglementaire est constitué par la Commission Paritaire de Formation (Joint Training Board dont le sigle est JTB) qui a pour but de conseiller le Directeur Général en matière de formation, de définir la politique de formation et d'en faire l'évaluation. Des organes spécifiques ont été mis en place pour organiser les différents programmes : le Groupe Formation et Développement, le Comité exécutif de formation (sigle TEC), le Comité d'enseignement académique. Des délégués divisionnaires à la formation (sigle DTO) servent de courroie de transmission entre ces organes, le personnel et le Service de l'Enseignement (Div. HR). La Division ST dont les activités présentent une grande variété se doit de poursuivre une politique de formation s...

  6. Effect of Pyruvate Decarboxylase Knockout on Product Distribution Using Pichia pastoris (Komagataella phaffii Engineered for Lactic Acid Production

    Directory of Open Access Journals (Sweden)

    Nadiele T. M. Melo

    2018-02-01

    Full Text Available Lactic acid is the monomer unit of the bioplastic poly-lactic acid (PLA. One candidate organism for lactic acid production is Pichia pastoris, a yeast widely used for heterologous protein production. Nevertheless, this yeast has a poor fermentative capability that can be modulated by controlling oxygen levels. In a previous study, lactate dehydrogenase (LDH activity was introduced into P. pastoris, enabling this yeast to produce lactic acid. The present study aimed to increase the flow of pyruvate towards the production of lactic acid in P. pastoris. To this end, a strain designated GLp was constructed by inserting the bovine lactic acid dehydrogenase gene (LDHb concomitantly with the interruption of the gene encoding pyruvate decarboxylase (PDC. Aerobic fermentation, followed by micro-aerophilic culture two-phase fermentations, showed that the GLp strain achieved a lactic acid yield of 0.65 g/g. The distribution of fermentation products demonstrated that the acetate titer was reduced by 20% in the GLp strain with a concomitant increase in arabitol production: arabitol increased from 0.025 g/g to 0.174 g/g when compared to the GS115 strain. Taken together, the results show a significant potential for P. pastoris in producing lactic acid. Moreover, for the first time, physiological data regarding co-product formation have indicated the redox balance limitations of this yeast.

  7. Escherichia coli pyruvate dehydrogenase complex: particle masses of the complex and component enzymes measured by scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    CaJacob, C.A.; Frey, P.A.; Hainfeld, J.F.; Wall, J.S.; Yang, H.

    1985-01-01

    Particle masses of the Escherichia coli pyruvate dehydrogenase (PDH) complex and its component enzymes have been measured by scanning transmission electron microscopy (STEM). The particle mass of PDH complex measured by STEM is 5.28 X 10(6) with a standard deviation of 0.40 X 10(6). The masses of the component enzymes are 2.06 X 10(5) for the dimeric pyruvate dehydrogenase (E1), 1.15 X 10(5) for dimeric dihydrolipoyl dehydrogenase (E3), and 2.20 X 10(6) for dihydrolipoyl transacetylase (E2), the 24-subunit core enzyme. STEM measurements on PDH complex incubated with excess E3 or E1 failed to detect any additional binding of E3 but showed that the complex would bind additional E1 under forcing conditions. The additional E1 subunits were bound too weakly to represent binding sites in an isolated or isolable complex. The mass measurements by STEM are consistent with the subunit composition 24:24:12 when interpreted in the light of the flavin content of the complex and assuming 24 subunits in the core enzyme (E2)

  8. Fusarium graminearum pyruvate dehydrogenase kinase 1 (FgPDK1 Is Critical for Conidiation, Mycelium Growth, and Pathogenicity.

    Directory of Open Access Journals (Sweden)

    Tao Gao

    Full Text Available Pyruvate dehydrogenase kinase (PDK is an important mitochondrial enzyme that blocks the production of acetyl-CoA by selectively inhibiting the activity of pyruvate dehydrogenase (PDH through phosphorylation. PDK is an effectively therapeutic target in cancer cells, but the physiological roles of PDK in phytopathogens are largely unknown. To address these gaps, a PDK gene (FgPDK1 was isolated from Fusarium graminearum that is an economically important pathogen infecting cereals. The deletion of FgPDK1 in F. graminearum resulted in the increase in PDH activity, coinciding with several phenotypic defects, such as growth retardation, failure in perithecia and conidia production, and increase in pigment formation. The ΔFgPDK1 mutants showed enhanced sensitivity to osmotic stress and cell membrane-damaging agent. Physiological detection indicated that reactive oxygen species (ROS accumulation and plasma membrane damage (indicated by PI staining, lipid peroxidation, and electrolyte leakage occurred in ΔFgPDK1 mutants. The deletion of FgPDK1 also prohibited the production of deoxynivalenol (DON and pathogenicity of F. graminearum, which may resulted from the decrease in the expression of Tri6. Taken together, this study firstly identified the vital roles of FgPDK1 in the development of phytopathogen F. graminearum, which may provide a potentially novel clue for target-directed development of agricultural fungicides.

  9. Roles of Pyruvate, NADH, and Mitochondrial Complex I in Redox Balance and Imbalance in β Cell Function and Dysfunction

    Directory of Open Access Journals (Sweden)

    Xiaoting Luo

    2015-01-01

    Full Text Available Pancreatic β cells not only use glucose as an energy source, but also sense blood glucose levels for insulin secretion. While pyruvate and NADH metabolic pathways are known to be involved in regulating insulin secretion in response to glucose stimulation, the roles of many other components along the metabolic pathways remain poorly understood. Such is the case for mitochondrial complex I (NADH/ubiquinone oxidoreductase. It is known that normal complex I function is absolutely required for episodic insulin secretion after a meal, but the role of complex I in β cells in the diabetic pancreas remains to be investigated. In this paper, we review the roles of pyruvate, NADH, and complex I in insulin secretion and hypothesize that complex I plays a crucial role in the pathogenesis of β cell dysfunction in the diabetic pancreas. This hypothesis is based on the establishment that chronic hyperglycemia overloads complex I with NADH leading to enhanced complex I production of reactive oxygen species. As nearly all metabolic pathways are impaired in diabetes, understanding how complex I in the β cells copes with elevated levels of NADH in the diabetic pancreas may provide potential therapeutic strategies for diabetes.

  10. 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.

  11. miR-378 Activates the Pyruvate-PEP Futile Cycle and Enhances Lipolysis to Ameliorate Obesity in Mice

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2016-03-01

    Full Text Available Obesity has been linked to many health problems, such as diabetes. However, there is no drug that effectively treats obesity. Here, we reveal that miR-378 transgenic mice display reduced fat mass, enhanced lipolysis, and increased energy expenditure. Notably, administering AgomiR-378 prevents and ameliorates obesity in mice. We also found that the energy deficiency seen in miR-378 transgenic mice was due to impaired glucose metabolism. This impairment was caused by an activated pyruvate-PEP futile cycle via the miR-378-Akt1-FoxO1-PEPCK pathway in skeletal muscle and enhanced lipolysis in adipose tissues mediated by miR-378-SCD1. Our findings demonstrate that activating the pyruvate-PEP futile cycle in skeletal muscle is the primary cause of elevated lipolysis in adipose tissues of miR-378 transgenic mice, and it helps orchestrate the crosstalk between muscle and fat to control energy homeostasis in mice. Thus, miR-378 may serve as a promising agent for preventing and treating obesity in humans.

  12. Cloning and characterization of F3PYC gene encoding pyruvate carboxylase in Aspergillus flavus strain (F3).

    Science.gov (United States)

    Qayyum, Sadia; Khan, Ibrar; Bhatti, Zulfiqar Ahmad; Peng, Changsheng

    2017-08-01

    Pyruvate carboxylase is a major enzyme for biosynthesis of organic acids like; citric acid, fumeric acid, and L-malic acid. These organic acids play very important role for biological remediation of heavy metals. In this study, gene walking method was used to clone and characterize pyruvate carboxylase gene (F3PYC) from heavy metal resistant indigenous fungal isolate Aspergillus flavus (F3). 3579 bp of an open reading frame which encodes 1193 amino acid protein (isoelectric point: 6.10) with a calculated molecular weight of 131.2008 kDa was characterized. Deduced protein showed 90-95% similarity to those deduced from PYC gene from different fungal strains including; Aspergillus parasiticus, Neosartorya fischeri, Aspergillus fumigatus, Aspergillus clavatus, and Aspergillus niger. Protein generated from the PYC gene was a homotetramer (α4) and having four potential N-linked glycosylation sites and had no signal peptide. Amongst most possible N-glycosylation sites were -N-S-S-I- at 36 amino acid, -N-G-T-V- at 237 amino acid, N-G-S-S- at 517 amino acid, and N-T-S-R- at 1111 amino acid, with several functions have been proposed for the carbohydrate moiety such as thermal stability, pH, and temperature optima for activity and stabilization of the three-dimensional structure. Hence, cloning of F3PYC gene from A. flavus has important biotechnological applications.

  13. Plasmodium pyruvate dehydrogenase activity is only essential for the parasite's progression from liver infection to blood infection.

    Science.gov (United States)

    Pei, Ying; Tarun, Alice S; Vaughan, Ashley M; Herman, Rob W; Soliman, Joanne M B; Erickson-Wayman, Alyssa; Kappe, Stefan H I

    2010-02-01

    Plasmodium parasites possess a single pyruvate dehydrogenase (PDH) enzyme complex that is localized to the plastid-like organelle known as the apicoplast. Unlike most eukaryotes, Plasmodium parasites lack a mitochondrial PDH. The PDH complex catalyses the conversion of pyruvate to acetyl-CoA, an important precursor for the tricarboxylic acid cycle and type II fatty acid synthesis (FAS II). In this study, using a rodent malaria model, we show that the PDH E1 alpha and E3 subunits colocalize with the FAS II enzyme FabI in the apicoplast of liver stages but are not significantly expressed in blood stages. Deletion of the E1 alpha or E3 subunit genes of Plasmodium yoelii PDH caused no defect in blood stage development, mosquito stage development or early liver stage development. However, the gene deletions completely blocked the ability of the e1 alpha(-) and e3(-) parasites to form exo-erythrocytic merozoites during late liver stage development, thus preventing the initiation of a blood stage infection. This phenotype is similar to that observed for deletions of genes involved in FAS II elongation. The data strongly support the hypothesis that the sole role of PDH is to provide acetyl-CoA for FAS II.

  14. Effect of Pyruvate Decarboxylase Knockout on Product Distribution Using Pichia pastoris (Komagataella phaffii) Engineered for Lactic Acid Production.

    Science.gov (United States)

    Melo, Nadiele T M; Mulder, Kelly C L; Nicola, André Moraes; Carvalho, Lucas S; Menino, Gisele S; Mulinari, Eduardo; Parachin, Nádia S

    2018-02-16

    Lactic acid is the monomer unit of the bioplastic poly-lactic acid (PLA). One candidate organism for lactic acid production is Pichia pastoris , a yeast widely used for heterologous protein production. Nevertheless, this yeast has a poor fermentative capability that can be modulated by controlling oxygen levels. In a previous study, lactate dehydrogenase (LDH) activity was introduced into P. pastoris, enabling this yeast to produce lactic acid. The present study aimed to increase the flow of pyruvate towards the production of lactic acid in P. pastoris . To this end, a strain designated GLp was constructed by inserting the bovine lactic acid dehydrogenase gene (LDHb) concomitantly with the interruption of the gene encoding pyruvate decarboxylase (PDC). Aerobic fermentation, followed by micro-aerophilic culture two-phase fermentations, showed that the GLp strain achieved a lactic acid yield of 0.65 g/g. The distribution of fermentation products demonstrated that the acetate titer was reduced by 20% in the GLp strain with a concomitant increase in arabitol production: arabitol increased from 0.025 g/g to 0.174 g/g when compared to the GS115 strain. Taken together, the results show a significant potential for P. pastoris in producing lactic acid. Moreover, for the first time, physiological data regarding co-product formation have indicated the redox balance limitations of this yeast.

  15. Functional pyruvate formate lyase pathway expressed with two different electron donors in Saccharomyces cerevisiae at aerobic growth.

    Science.gov (United States)

    Zhang, Yiming; Dai, Zongjie; Krivoruchko, Anastasia; Chen, Yun; Siewers, Verena; Nielsen, Jens

    2015-06-01

    Pyruvate formate lyase (PFL) is characterized as an enzyme functional at anaerobic conditions, since the radical in the enzyme's active form is sensitive to oxygen. In this study, PFL and its activating enzyme from Escherichia coli were expressed in a Saccharomyces cerevisiae strain lacking pyruvate decarboxylase and having a reduced glucose uptake rate due to a mutation in the transcriptional regulator Mth1, IMI076 (Pdc(-) MTH1-ΔT ura3-52). PFL was expressed with two different electron donors, reduced ferredoxin or reduced flavodoxin, respectively, and it was found that the coexpression of either of these electron donors had a positive effect on growth under aerobic conditions, indicating increased activity of PFL. The positive effect on growth was manifested as a higher final biomass concentration and a significant increase in transcription of formate dehydrogenases. Among the two electron donors reduced flavodoxin was found to be a better electron donor than reduced ferredoxin. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Molecular identification and characterization of the pyruvate decarboxylase gene family associated with latex regeneration and stress response in rubber tree.

    Science.gov (United States)

    Long, Xiangyu; He, Bin; Wang, Chuang; Fang, Yongjun; Qi, Jiyan; Tang, Chaorong

    2015-02-01

    In plants, ethanolic fermentation occurs not only under anaerobic conditions but also under aerobic conditions, and involves carbohydrate and energy metabolism. Pyruvate decarboxylase (PDC) is the first and the key enzyme of ethanolic fermentation, which branches off the main glycolytic pathway at pyruvate. Here, four PDC genes were isolated and identified in a rubber tree, and the protein sequences they encode are very similar. The expression patterns of HbPDC4 correlated well with tapping-simulated rubber productivity in virgin rubber trees, indicating it plays an important role in regulating glycometabolism during latex regeneration. HbPDC1, HbPDC2 and HbPDC3 had striking expressional responses in leaves and bark to drought, low temperature and high temperature stresses, indicating that the HbPDC genes are involve in self-protection and defense in response to various abiotic and biotic stresses during rubber tree growth and development. To understand ethanolic fermentation in rubber trees, it will be necessary to perform an in-depth study of the regulatory pathways controlling the HbPDCs in the future. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. Simultaneous Hyperpolarized 13C-Pyruvate MRI and 18F-FDG PET (HyperPET) in 10 Dogs with Cancer

    DEFF Research Database (Denmark)

    Gutte, Henrik; Hansen, Adam E; Larsen, Majbrit M E

    2015-01-01

    With the introduction of combined PET/MR spectroscopic (MRS) imaging, it is now possible to directly and indirectly image the Warburg effect with hyperpolarized (13)C-pyruvate and (18)F-FDG PET imaging, respectively, via a technique we have named hyperPET. The main purpose of this present study...... was to establish a practical workflow for performing (18)F-FDG PET and hyperpolarized (13)C-pyruvate MRS imaging simultaneously for tumor tissue characterization and on a larger scale test its feasibility. In addition, we evaluated the correlation between (18)F-FDG uptake and (13)C-lactate production. Ten dogs...... with biopsy-verified spontaneous malignant tumors were included for imaging. All dogs underwent a protocol of simultaneous (18)F-FDG PET, anatomic MR, and hyperpolarized dynamic nuclear polarization with (13)C-pyruvate imaging. The data were acquired using a combined clinical PET/MR imaging scanner. We found...

  18. Fast metabolite mapping in the pig heart after injection of hyperpolarized 13C-pyruvate with low-flip angle balanced steady-state free precession imaging.

    Science.gov (United States)

    Månsson, Sven; Petersson, J Stefan; Scheffler, Klaus

    2012-12-01

    The conversion of hyperpolarized (13)C pyruvate to metabolic products in the Krebs cycle provides valuable information about the metabolic status and the viability of the myocardium. Therefore, imaging methods must be able to spectrally discriminate different (13)C metabolites. However, the requirement for spectral selectivity conflicts with the demands for rapid image acquisition and high spatial resolution in cardiac imaging. In this work, the feasibility of a balanced steady state free precession sequence with low flip angles was investigated in the pig heart after injection of hyperpolarized (13)C(1)-pyruvate. Using cardiac gating, it was possible to acquire (13)C-bicarbonate images within a single heartbeat (acquisition time 150 ms) without destroying the substrate signal from the hyperpolarized pyruvate. Therefore, the technique may be useful in dynamic studies of cardiac metabolism. Copyright © 2012 Wiley Periodicals, Inc.

  19. Studies on the nitroso-glyoxylate reaction. Relative hydroxamic acid production by glyoxylate, pyruvate, and formaldehyde in reactions with 4-nitrosobiphenyl.

    Science.gov (United States)

    Corbett, M D; Corbett, B R

    1993-01-01

    The pH rate profiles for the reactions of 4-nitrosobiphenyl with three carbonyl substrates in aqueous buffers were determined by use of chromatographic and spectrophotometric methods. Glyoxylate and formaldehyde caused the conversion of 4-nitrosobiphenyl to N-(4-biphenyl)-formohydroxamic acid, while pyruvate resulted in the production of N-(4-biphenyl)acetohydroxamic acid. The dramatic effect of pH on the kinetics of these reactions provided considerable information concerning the nature of these reactions. The reactions with pyruvate and formaldehyde displayed similar pH rate profiles and were significant only at acidic pH. Glyoxylate displayed a pH rate profile that differed markedly from those of pyruvate and formaldehyde as the pH was increased beyond 2.0. The ability of glyoxylate to convert 4-nitrosobiphenyl to the hydroxamic acid increased rapidly in the pH range 2.0-4.0, above which the pH dependency was constant. This biphasic appearance of the pH rate profile was unique to glyoxylate, since the reactions of pyruvate and formaldehyde became extremely slow as solution neutrality was approached. A second substrate, 4-chloronitrosobenzene, displayed similar pH rate profiles in its reactions with these carbonyl substrates. For 4-nitrosobiphenyl, hydroxamic acid formation by glyoxylate was 10(4) times faster than that by pyruvate at neutral pH, but only about 3-fold faster at pH 1.0. The appearance of the pH rate profile for glyoxylate suggested that this alpha-oxo acid reacts with nitrosoarenes at neutrality via a pathway that is insignificant for pyruvate or formaldehyde. Thus, the nitroso-glyoxylate reaction is unique to this alpha-oxo acid under physiological pH conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Metabolic fate of the carboxyl groups of malate and pyruvate and their influence on δ13C of leaf respired CO2 during light enhanced dark respiration

    Directory of Open Access Journals (Sweden)

    Marco M Lehmann

    2016-06-01

    Full Text Available The enhanced CO2 release of illuminated leaves transferred into darkness, termed light enhanced dark respiration (LEDR, is often associated with an increase in the carbon isotope ratio of the respired CO2 (δ13CLEDR. The latter has been hypothesized to result from different respiratory substrates and decarboxylation reactions in various metabolic pathways, which are poorly understood so far. To provide a better insight into the underlying metabolic processes of δ13CLEDR, we fed position-specific 13C-labelled malate and pyruvate via the xylem stream to leaves of species with high and low δ13CLEDR values (Halimium halimifolium and Oxalis triangularis, respectively. During respective label application, we determined label-derived leaf 13CO2 respiration using laser spectroscopy and the 13C allocation to metabolic fractions during light-dark transitions. Our results clearly show that both carboxyl groups (C-1 and C-4 position of malate similarly influence respiration and metabolic fractions in both species, indicating possible isotope randomization of the carboxyl groups of malate by the fumarase reaction. While C-2 position of pyruvate was only weakly respired, the species-specific difference in natural δ13CLEDR patterns were best reflected by the 13CO2 respiration patterns of the C-1 position of pyruvate. Furthermore, 13C label from malate and pyruvate were mainly allocated to amino and organic acid fractions in both species and only little to sugar and lipid fractions. In summary, our results suggest that respiration of both carboxyl groups of malate (via fumarase by tricarboxylic acid cycle reactions or by NAD-malic enzyme influences δ13CLEDR. The latter supplies the pyruvate dehydrogenase reaction, which in turn determines natural δ13CLEDR pattern by releasing the C-1 position of pyruvate.

  1. Hyperpolarized [1-13C]Pyruvate MRI identifies metabolic differences pertaining to the fasted and fed state in porcine cardiac metabolism

    DEFF Research Database (Denmark)

    Tougaard, Rasmus Stilling; Søvsø Szocska Hansen, Esben; Laustsen, Christoffer

    for increasing hyperpolarized [1-13C]Pyruvate signal in the heart. All metabolic ratios were higher in fed animals with no additional variance. This indicates the role of pyruvate uptake to be more important in pigs than in rodents, underlining the need for large animals in metabolic research, and also suggests......Standardized large animal models for cardiac hyperpolarized MR metabolic studies are becoming increasingly important as translation into human trials progresses. We employed a porcine (n=17) model of fasting/feeding to study these two states and to examine normal feeding as a standardized model...

  2. Comparative kinetic studies of Mn2+-activated and fructose-1,6-P-modified Mg2+-activated pyruvate kinase from Concholepas concholepas.

    Science.gov (United States)

    Carvajal, N; González, R; Morán, A; Oyarce, A M

    1985-01-01

    Initial velocity and product inhibition studies of Mn2+-activated and FDP-modified Mg2+-activated pyruvate kinase from Concholepas concholepas, were performed. Evidence is presented to show that the Mn2+-enzyme catalyzes an ordered sequential mechanism, with ADP being the first substrate and pyruvate the last product. The results presented are consistent with a random combination of reactants with the FDP-modified Mg2+-activated enzyme and the formation of the dead-end complexes enzyme ADP-ATP and enzyme-PEP-ATP.

  3. EFEK ANTIPIRETIK KOMBINASI EKSTRAK DAUN COCOR BEBEK (Kalanchoe pinnata L. DAN EKSTRAK DAUN TEMBELEKAN(Lantana camara L. PERS.TERHADAP MARMUT (Cavia porcellus DENGAN DEMAM YANG DIINDUKSI PEPTON

    Directory of Open Access Journals (Sweden)

    Heni Purwitasari

    2017-03-01

    Full Text Available Cocor Bebek (Kalanchoe pinnata L. is a medicinal plant that has been used as traditional medicine for long period, used to fight fever, but it empirically leaves of  Tembelekan (Lantana camara L. are also generally primarily used to treat fever. Research on the effects of the combination of Cocor Bebek’s leaf extract (Kalanchoe pinnata L. and the leaf extract of tembelekan (Lantana camara L. Pers on male guinea pig (Cavia porcellus is induced peptone 5% at a dose of 150 mg / kg body weight. With the aim to determine the effect of the combination and determine the effects of the most effective as an antipyretic. Extracts prepared by maceration method using ethanol 95%. Marmots were divided into 4 groups. Each guinea pig was induced using peptone 5%. The first group was given Na CMC as a negative control group 2nd given a combination of one dose combinations (50 + 720. Group 3 was given a second dose combination (100 + 720. Group-4 were given a 3-dose combination (150 + 720. Temperature measurement is carried out for 2 hours with a 30 minute interval. Data were analyzed temperature measurements were statistically analyzed using ANOVA (Analisys Of Variance. The research result was addressing, that the combination of extracts can reduce fever. The combination is most effective as an antipyretic is cocor duck leaf extract 50 mg and 720 mg tembelekan leaf extract (50 + 720.

  4. Potential of pomegranate fruit extract (Punica granatum Linn.) to increase vascular endothelial growth factor and platelet-derived growth factor expressions on the post-tooth extraction wound of Cavia cobaya.

    Science.gov (United States)

    Nirwana, Intan; Rachmadi, Priyawan; Rianti, Devi

    2017-08-01

    Pomegranates fruit extracts have several activities, among others, anti-inflammatory, antibacterial, and antioxidants that have the main content punicalagin and ellagic acid. Pomegranate has the ability of various therapies through different mechanisms. Vascular endothelial growth factor (VEGF) function was to form new blood vessels produced by various cells one of them was macrophages. Platelet-derived growth factor (PDGF) was a growth factor proven chemotactic, increased fibroblast proliferation and collagen matrix production. In addition, VEGF and PDGF synergize in their ability to vascularize tissues. The PDGF function was to stabilize and regulate maturation of new blood vessels. Activities of pomegranate fruit extract were observed by measuring the increased of VEGF and PDGF expression as a marker of wound healing process. To investigate the potential of pomegranate extracts on the tooth extraction wound to increase the expression of VEGF and PDGF on the 4 th day of wound healing process. This study used 12 Cavia cobaya , which were divided into two groups, namely, the provision of 3% sodium carboxymethyl cellulose and pomegranate extract. The 12 C. cobaya would be executed on the 4 th day, the lower jaw of experimental animals was taken, decalcified about 30 days. The expression of VEGF and PDGF was examined using immunohistochemical techniques. The differences of VEGF and PDGF expression were evaluated statistically using t-test. Statistically analysis showed that there were significant differences between control and treatment groups (p<0.05). Pomegranate fruit extract administration increased VEGF and PDGF expression on post-tooth extraction wound.

  5. Teknisk Ståbi

    DEFF Research Database (Denmark)

    Teknisk Ståbi er de bygningsprojekterendes og entreprenørers håndbog. Den dækker matematik, fysik, statestik, laster og sikkerhed samt beggematerialerne: beton, stål, træ, murværk, letbeton, glas og endelig fundering. Denne udgave er en næsten totalrevision, baseret på de nye Eurocodes, der afløs...

  6. An internal deletion in MTH1 enables growth on glucose of pyruvate-decarboxylase negative, non-fermentative Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Oud Bart

    2012-09-01

    Full Text Available Abstract Background Pyruvate-decarboxylase negative (Pdc- strains of Saccharomyces cerevisiae combine the robustness and high glycolytic capacity of this yeast with the absence of alcoholic fermentation. This makes Pdc-S. cerevisiae an interesting platform for efficient conversion of glucose towards pyruvate-derived products without formation of ethanol as a by-product. However, Pdc- strains cannot grow on high glucose concentrations and require C2-compounds (ethanol or acetate for growth under conditions with low glucose concentrations, which hitherto has limited application in industry. Results Genetic analysis of a Pdc- strain previously evolved to overcome these deficiencies revealed a 225bp in-frame internal deletion in MTH1, encoding a transcriptional regulator involved in glucose sensing. This internal deletion contains a phosphorylation site required for degradation, thereby hypothetically resulting in increased stability of the protein. Reverse engineering of this alternative MTH1 allele into a non-evolved Pdc- strain enabled growth on 20 g l-1 glucose and 0.3% (v/v ethanol at a maximum specific growth rate (0.24 h-1 similar to that of the evolved Pdc- strain (0.23 h-1. Furthermore, the reverse engineered Pdc- strain grew on glucose as sole carbon source, albeit at a lower specific growth rate (0.10 h-1 than the evolved strain (0.20 h-1. The observation that overexpression of the wild-type MTH1 allele also restored growth of Pdc-S. cerevisiae on glucose is consistent with the hypothesis that the internal deletion results in decreased degradation of Mth1. Reduced degradation of Mth1 has been shown to result in deregulation of hexose transport. In Pdc- strains, reduced glucose uptake may prevent intracellular accumulation of pyruvate and/or redox problems, while release of glucose repression due to the MTH1 internal deletion may contribute to alleviation of the C2-compound auxotrophy. Conclusions In this study we have discovered and

  7. An internal deletion in MTH1 enables growth on glucose of pyruvate-decarboxylase negative, non-fermentative Saccharomyces cerevisiae.

    Science.gov (United States)

    Oud, Bart; Flores, Carmen-Lisset; Gancedo, Carlos; Zhang, Xiuying; Trueheart, Joshua; Daran, Jean-Marc; Pronk, Jack T; van Maris, Antonius J A

    2012-09-15

    Pyruvate-decarboxylase negative (Pdc⁻) strains of Saccharomyces cerevisiae combine the robustness and high glycolytic capacity of this yeast with the absence of alcoholic fermentation. This makes Pdc⁻S. cerevisiae an interesting platform for efficient conversion of glucose towards pyruvate-derived products without formation of ethanol as a by-product. However, Pdc⁻ strains cannot grow on high glucose concentrations and require C₂-compounds (ethanol or acetate) for growth under conditions with low glucose concentrations, which hitherto has limited application in industry. Genetic analysis of a Pdc⁻ strain previously evolved to overcome these deficiencies revealed a 225 p in-frame internal deletion in MTH1, encoding a transcriptional regulator involved in glucose sensing. This internal deletion contains a phosphorylation site required for degradation, thereby hypothetically resulting in increased stability of the protein. Reverse engineering of this alternative MTH1 allele into a non-evolved Pdc⁻ strain enabled growth on 20 g l⁻¹ glucose and 0.3% (v/v) ethanol at a maximum specific growth rate (0.24 h⁻¹) similar to that of the evolved Pdc⁻ strain (0.23 h⁻¹). Furthermore, the reverse engineered Pdc⁻ strain grew on glucose as sole carbon source, albeit at a lower specific growth rate (0.10 h⁻¹) than the evolved strain (0.20 h⁻¹). The observation that overexpression of the wild-type MTH1 allele also restored growth of Pdc⁻S. cerevisiae on glucose is consistent with the hypothesis that the internal deletion results in decreased degradation of Mth1. Reduced degradation of Mth1 has been shown to result in deregulation of hexose transport. In Pdc⁻ strains, reduced glucose uptake may prevent intracellular accumulation of pyruvate and/or redox problems, while release of glucose repression due to the MTH1 internal deletion may contribute to alleviation of the C₂-compound auxotrophy. In this study we have discovered and characterised a

  8. FoxO1 regulates myocardial glucose oxidation rates via transcriptional control of pyruvate dehydrogenase kinase 4 expression.

    Science.gov (United States)

    Gopal, Keshav; Saleme, Bruno; Al Batran, Rami; Aburasayn, Hanin; Eshreif, Amina; Ho, Kim L; Ma, Wayne K; Almutairi, Malak; Eaton, Farah; Gandhi, Manoj; Park, Edwards A; Sutendra, Gopinath; Ussher, John R

    2017-09-01

    Pyruvate dehydrogenase (PDH) is the rate-limiting enzyme for glucose oxidation and a critical regulator of metabolic flexibility during the fasting to feeding transition. PDH is regulated via both PDH kinases (PDHK) and PDH phosphatases, which phosphorylate/inactivate and dephosphorylate/activate PDH, respectively. Our goal was to determine whether the transcription factor forkhead box O1 (FoxO1) regulates PDH activity and glucose oxidation in the heart via increasing the expression of Pdk4 , the gene encoding PDHK4. To address this question, we differentiated H9c2 myoblasts into cardiac myocytes and modulated FoxO1 activity, after which Pdk4 /PDHK4 expression and PDH phosphorylation/activity were assessed. We assessed binding of FoxO1 to the Pdk4 promoter in cardiac myocytes in conjunction with measuring the role of FoxO1 on glucose oxidation in the isolated working heart. Both pharmacological (1 µM AS1842856) and genetic (siRNA mediated) inhibition of FoxO1 decreased Pdk4 /PDHK4 expression and subsequent PDH phosphorylation in H9c2 cardiac myocytes, whereas 10 µM dexamethasone-induced Pdk4 /PDHK4 expression was abolished via pretreatment with 1 µM AS1842856. Furthermore, transfection of H9c2 cardiac myocytes with a vector expressing FoxO1 increased luciferase activity driven by a Pdk4 promoter construct containing the FoxO1 DNA-binding element region, but not in a Pdk4 promoter construct lacking this region. Finally, AS1842856 treatment in fasted mice enhanced glucose oxidation rates during aerobic isolated working heart perfusions. Taken together, FoxO1 directly regulates Pdk4 transcription in the heart, thereby controlling PDH activity and subsequent glucose oxidation rates. NEW & NOTEWORTHY Although studies have shown an association between FoxO1 activity and pyruvate dehydrogenase kinase 4 expression, our study demonstrated that pyruvate dehydrogenase kinase 4 is a direct transcriptional target of FoxO1 (but not FoxO3/FoxO4) in the heart. Furthermore, we

  9. Apparent target size of rat brain benzodiazepine receptor, acetylcholinesterase, and pyruvate kinase is highly influenced by experimental conditions

    International Nuclear Information System (INIS)

    Nielsen, M.; Braestrup, C.

    1988-01-01

    Radiation inactivation is a method to determine the apparent target size of molecules. In this report we examined whether radiation inactivation of various enzymes and brain receptors is influenced by the preparation of samples preceding irradiation. The apparent target sizes of endogenous acetylcholinesterase and pyruvate kinase from rat brain and from rabbit muscle and benzodiazepine receptor from rat brain were investigated in some detail. In addition the target sizes of alcohol dehydrogenase (from yeast and horse liver), beta-galactosidase (from Escherichia coli), lactate dehydrogenase (endogenous from rat brain), and 5-HT2 receptors, acetylcholine muscarine receptors, and [ 35 S] butyl bicyclophosphorothionate tertiary binding sites from rat brain were determined. The results show that apparent target sizes are highly influenced by the procedure applied for sample preparation before irradiation. The data indicate that irradiation of frozen whole tissue as opposed to lyophilized tissue or frozen tissue homogenates will estimate the smallest and most relevant functional target size of a receptor or an enzyme

  10. Crystallization and preliminary X-ray diffraction analysis of ω-amino acid:pyruvate transaminase from Chromobacterium violaceum

    International Nuclear Information System (INIS)

    Sayer, Christopher; Isupov, Michail N.; Littlechild, Jennifer A.

    2007-01-01

    An ω-amino acid:pyruvate transaminase from C. violaceum has been purified and crystallized in two crystal forms. The structure has been solved using molecular replacement. The enzyme ω-transaminase catalyses the conversion of chiral ω-amines to ketones. The recombinant enzyme from Chromobacterium violaceum has been purified to homogeneity. The enzyme was crystallized from PEG 4000 using the microbatch method. Data were collected to 1.7 Å resolution from a crystal belonging to the triclinic space group P1, with unit-cell parameters a = 58.9, b = 61.9, c = 63.9 Å, α = 71.9, β = 87.0, γ = 74.6°. Data were also collected to 1.95 Å from a second triclinic crystal form. The structure has been solved using the molecular-replacement method

  11. The MDM2-p53-pyruvate carboxylase signalling axis couples mitochondrial metabolism to glucose-stimulated insulin secretion in pancreatic β-cells

    DEFF Research Database (Denmark)

    Li, Xiaomu; Cheng, Kenneth K. Y.; Liu, Zhuohao

    2016-01-01

    deletion or pharmacological inhibition of its negative regulator MDM2, impairs GSIS, leading to glucose intolerance in mice. Mechanistically, p53 activation represses the expression of the mitochondrial enzyme pyruvate carboxylase (PC), resulting in diminished production of the TCA cycle intermediates...

  12. The level of pyruvate-formate lyase controls the shift from homolactic to mixed-acid product formation in Lactococcus lactis

    DEFF Research Database (Denmark)

    Melchiorsen, C.R.; Jokumsen, K.V.; Villadsen, John

    2002-01-01

    Regulation of pyruvate-formate lyase (PFL) activity in vivo plays a central role in the shift from homolactic to mixed-acid product formation observed during the growth of Lactococcus lactis on glucose and galactose, respectively. Characterisation of L lactis MG1363 in anaerobic batch cultures sh...

  13. Simultaneous hyperpolarized 13C-pyruvate MRI and 18F-FDG-PET in cancer (hyperPET)

    DEFF Research Database (Denmark)

    Borgwardt, Henrik Gutte; Hansen, Adam Espe; Henriksen, Sarah T.

    2015-01-01

    In this paper we demonstrate, for the first time, the feasibility of a new imaging concept - combined hyperpolarized (13)C-pyruvate magnetic resonance spectroscopic imaging (MRSI) and (18)F-FDG-PET imaging. This procedure was performed in a clinical PET/MRI scanner with a canine cancer patient. W...

  14. Interaction between the thyroid hormone receptor and co-factors on the promoter of the gene encoding phospho enol pyruvate carboxykinase

    NARCIS (Netherlands)

    Schmidt, E. D.; van Beeren, M.; Glass, C. K.; Wiersinga, W. M.; Lamers, W. H.

    1993-01-01

    Using transient transfection studies we localized a thyroid hormone-responsive element on the promoter of the rat phospho-enol pyruvate carboxykinase gene between 355 and 174 bp upstream of the transcription start site. DNAse 1 footprinting analysis within this region showed that a 28 bp fragment at

  15. Elevated levels of 14-3-3 proteins, serotonin, gamma enolase and pyruvate kinase identified in clinical samples from patients diagnosed with colorectal cancer

    Czech Academy of Sciences Publication Activity Database

    Dowling, P.; Hughes, D. J.; Larkin, A.M.; Meiller, J.; Henry, M.; Meleady, P.; Lynch, V.; Pardini, B.; Naccarati, A.; Levý, M.; Vodička, Pavel; Neary, P.; Clynes, M.

    2015-01-01

    Roč. 441, feb. (2015), s. 133-141 ISSN 0009-8981 Institutional support: RVO:68378041 Keywords : biomarkers * colorectal cancer * proteomics * mass spectrometry * 14-3-3 proteins * pyruvate kinase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.799, year: 2015

  16. Investigations on organic fungicides. X. Pyruvic acid accumulation and its relation to the phenomenon of inversion growth as effected by sodium dimethyldithiocarbamate

    NARCIS (Netherlands)

    Kaars Sijpesteijn, A.; Kerk, G.J.M. van der

    1956-01-01

    1. 1. Sodium dimethyldithiocarbamate (NaDDC) induces spores and mycelium of A. niger and P. italicum to accumulate pyruvic acid in the medium. This accumulation shows a maximum at those NaDDC concentrations which in growth experiments on agar lead to the zone of inversion growth, and decreases

  17. Starmerella bombicola influences the metabolism of Saccharomyces cerevisiae at pyruvate decarboxylase and alcohol dehydrogenase level during mixed wine fermentation

    Science.gov (United States)

    2012-01-01

    Background The use of a multistarter fermentation process with Saccharomyces cerevisiae and non-Saccharomyces wine yeasts has been proposed to simulate natural must fermentation and to confer greater complexity and specificity to wine. In this context, the combined use of S. cerevisiae and immobilized Starmerella bombicola cells (formerly Candida stellata) was assayed to enhance glycerol concentration, reduce ethanol content and to improve the analytical composition of wine. In order to investigate yeast metabolic interaction during controlled mixed fermentation and to evaluate the influence of S. bombicola on S. cerevisiae, the gene expression and enzymatic activity of two key enzymes of the alcoholic fermentation pathway such as pyruvate decarboxylase (Pdc1) and alcohol dehydrogenase (Adh1) were studied. Results The presence of S. bombicola immobilized cells in a mixed fermentation trial confirmed an increase in fermentation rate, a combined consumption of glucose and fructose, an increase in glycerol and a reduction in the production of ethanol as well as a modification in the fermentation of by products. The alcoholic fermentation of S. cerevisiae was also influenced by S. bombicola immobilized cells. Indeed, Pdc1 activity in mixed fermentation was lower than that exhibited in pure culture while Adh1 activity showed an opposite behavior. The expression of both PDC1 and ADH1 genes was highly induced at the initial phase of fermentation. The expression level of PDC1 at the end of fermentation was much higher in pure culture while ADH1 level was similar in both pure and mixed fermentations. Conclusion In mixed fermentation, S. bombicola immobilized cells greatly affected the fermentation behavior of S. cerevisiae and the analytical composition of wine. The influence of S. bombicola on S. cerevisiae was not limited to a simple additive contribution. Indeed, its presence caused metabolic modifications during S. cerevisiae fermentation causing variation in the gene

  18. Amino acid substitutions at glutamate-354 in dihydrolipoamide dehydrogenase of Escherichia coli lower the sensitivity of pyruvate dehydrogenase to NADH.

    Science.gov (United States)

    Sun, Zhentao; Do, Phi Minh; Rhee, Mun Su; Govindasamy, Lakshmanan; Wang, Qingzhao; Ingram, Lonnie O; Shanmugam, K T

    2012-05-01

    Pyruvate dehydrogenase (PDH) of Escherichia coli is inhibited by NADH. This inhibition is partially reversed by mutational alteration of the dihydrolipoamide dehydrogenase (LPD) component of the PDH complex (E354K or H322Y). Such a mutation in lpd led to a PDH complex that was functional in an anaerobic culture as seen by restoration of anaerobic growth of a pflB, ldhA double mutant of E. coli utilizing a PDH- and alcohol dehydrogenase-dependent homoethanol fermentation pathway. The glutamate at position 354 in LPD was systematically changed to all of the other natural amino acids to evaluate the physiological consequences. These amino acid replacements did not affect the PDH-dependent aerobic growth. With the exception of E354M, all changes also restored PDH-dependent anaerobic growth of and fermentation by an ldhA, pflB double mutant. The PDH complex with an LPD alteration E354G, E354P or E354W had an approximately 20-fold increase in the apparent K(i) for NADH compared with the native complex. The apparent K(m) for pyruvate or NAD(+) for the mutated forms of PDH was not significantly different from that of the native enzyme. A structural model of LPD suggests that the amino acid at position 354 could influence movement of NADH from its binding site to the surface. These results indicate that glutamate at position 354 plays a structural role in establishing the NADH sensitivity of LPD and the PDH complex by restricting movement of the product/substrate NADH, although this amino acid is not directly associated with NAD(H) binding.

  19. Cloning and characterization of pyruvate carboxylase gene responsible for calcium malate overproduction in Penicillium viticola 152 and its expression analysis.

    Science.gov (United States)

    Khan, Ibrar; Qayyum, Sadia; Ahmed, Shehzad; Maqbool, Farhana; Tauseef, Isfahan; Haleem, Kashif Syed; Chi, Zhen-Ming

    2017-03-20

    In this study, a pyruvate carboxylase gene (PYC) from a marine fungus Penicillium viticola 152 isolated from marine algae was cloned and characterized by using Genome Walking method. An open reading frame (ORF) of The PYC gene (accession number: KM593097) had 3582bp encoding 1193 amino acid protein (isoelectric point: 5.01) with a calculated molecular weight of 131.2757kDa. A putative promoter (intronless) of the gene was located at -666bp and contained a TATA box, several CAAT boxes, the 5'-SYGGRG-3' and a 5'-HGATAR-3' sequences. A consensus polyadenylation site (AATAAA) was also observed at +10bp downstream of the ORF. The protein deduced from the PYC gene had no signal peptide, was a homotetramer (4), and had the four functional domains. Furthermore, PYC protein also had three potential N-linked glycosylation sites, among them, -N-S-T-I- at 36 amino acid, -N-G-T-V- at 237 amino acid, and -N-G-S-S- at 517 amino acid were the most possible N-glycosylation sites. After expression of the PYC gene of P. viticola 152 in medium supplemented with CSL and biotin, it was found that the specific pyruvate carboxylase activity in MA production medium supplemented with CSL was much higher (0.5U/mg) than in MA medium supplemented with biotin (0.3U/mg), suggesting that optimal concentration of CSL is required for increased expression of the PYC gene, which is responsible for high level production of malic acid in P. viticola 152 strain. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Interaction Between the Biotin Carboxyl Carrier Domain and the Biotin Carboxylase Domain in Pyruvate Carboxylase from Rhizobium etli†

    Science.gov (United States)

    Lietzan, Adam D.; Menefee, Ann L.; Zeczycki, Tonya N.; Kumar, Sudhanshu; Attwood, Paul V.; Wallace, John C.; Cleland, W. Wallace; Maurice, Martin St.

    2011-01-01

    Pyruvate carboxylase (PC) catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. To effect catalysis, the tethered biotin of PC must gain access to active sites in both the biotin carboxylase domain and the carboxyl transferase domain. Previous studies have demonstrated that a mutation of threonine 882 to alanine in PC from Rhizobium etli renders the carboxyl transferase domain inactive and favors the positioning of biotin in the biotin carboxylase domain. We report the 2.4 Å resolution X-ray crystal structure of the Rhizobium etli PC T882A mutant which reveals the first high-resolution description of the domain interaction between the biotin carboxyl carrier protein domain and the biotin carboxylase domain. The overall quaternary arrangement of Rhizobium etli PC remains highly asymmetrical and is independent of the presence of allosteric activator. While biotin is observed in the biotin carboxylase domain, its access to the active site is precluded by the interaction between Arg353 and Glu248, revealing a mechanism for regulating carboxybiotin access to the BC domain active site. The binding location for the biotin carboxyl carrier protein domain demonstrates that tethered biotin cannot bind in the biotin carboxylase domain active site in the same orientation as free biotin, helping to explain the difference in catalysis observed between tethered biotin and free biotin substrates in biotin carboxylase enzymes. Electron density located in the biotin carboxylase domain active site is assigned to phosphonoacetate, offering a probable location for the putative carboxyphosphate intermediate formed during biotin carboxylation. The insights gained from the T882A Rhizobium etli PC crystal structure provide a new series of catalytic snapshots in PC and offer a revised perspective on catalysis in the biotin-dependent enzyme family. PMID:21958016

  1. Cross-linking and 1H n.m.r. spectroscopy of the pyruvate dehydrogenase complex of Escherichia coli.

    Science.gov (United States)

    Packman, L C; Perham, R N; Roberts, G C

    1982-08-01

    The pyruvate dehydrogenase complex of Escherichia coli was treated with o-phenylene bismaleimide in the presence of the substrate pyruvate, producing almost complete cross-linking of the lipoate acetyltransferase polypeptide chains as judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This took place without effect on the catalytic activities of the other two component enzymes and with little evidence of cross-links being formed with other types of protein subunit. Limited proteolysis with trypsin indicated that the cross-links were largely confined to the lipoyl domains of the lipoate acetyltransferase component of the same enzyme particle. This intramolecular cross-linking had no effect on the very sharp resonances observed in the (1)H n.m.r. spectrum of the enzyme complex, which derive from regions of highly mobile polypeptide chain in the lipoyl domains. Comparison of the spin-spin relaxation times, T(2), with the measured linewidths supported the idea that the highly mobile region is best characterized as a random coil. Intensity measurements in spin-echo spectra showed that it comprises a significant proportion (probably not less than one-third) of a lipoyl domain and is thus much more than a small hinge region, but there was insufficient intensity in the resonances to account for the whole lipoyl domain. On the other hand, no evidence was found in the (1)H n.m.r. spectrum for a substantial structured region around the lipoyl-lysine residues that was free to move on the end of this highly flexible connection. If such a structured region were bound to other parts of the enzyme complex for a major part of its time, its resonances might be broadened sufficiently to evade detection by (1)H n.m.r. spectroscopy.

  2. Starmerella bombicola influences the metabolism of Saccharomyces cerevisiae at pyruvate decarboxylase and alcohol dehydrogenase level during mixed wine fermentation

    Directory of Open Access Journals (Sweden)

    Milanovic Vesna

    2012-02-01

    Full Text Available Abstract Background The use of a multistarter fermentation process with Saccharomyces cerevisiae and non-Saccharomyces wine yeasts has been proposed to simulate natural must fermentation and to confer greater complexity and specificity to wine. In this context, the combined use of S. cerevisiae and immobilized Starmerella bombicola cells (formerly Candida stellata was assayed to enhance glycerol concentration, reduce ethanol content and to improve the analytical composition of wine. In order to investigate yeast metabolic interaction during controlled mixed fermentation and to evaluate the influence of S. bombicola on S. cerevisiae, the gene expression and enzymatic activity of two key enzymes of the alcoholic fermentation pathway such as pyruvate decarboxylase (Pdc1 and alcohol dehydrogenase (Adh1 were studied. Results The presence of S. bombicola immobilized cells in a mixed fermentation trial confirmed an increase in fermentation rate, a combined consumption of glucose and fructose, an increase in glycerol and a reduction in the production of ethanol as well as a modification in the fermentation of by products. The alcoholic fermentation of S. cerevisiae was also influenced by S. bombicola immobilized cells. Indeed, Pdc1 activity in mixed fermentation was lower than that exhibited in pure culture while Adh1 activity showed an opposite behavior. The expression of both PDC1 and ADH1 genes was highly induced at the initial phase of fermentation. The expression level of PDC1 at the end of fermentation was much higher in pure culture while ADH1 level was similar in both pure and mixed fermentations. Conclusion In mixed fermentation, S. bombicola immobilized cells greatly affected the fermentation behavior of S. cerevisiae and the analytical composition of wine. The influence of S. bombicola on S. cerevisiae was not limited to a simple additive contribution. Indeed, its presence caused metabolic modifications during S. cerevisiae fermentation

  3. Starmerella bombicola influences the metabolism of Saccharomyces cerevisiae at pyruvate decarboxylase and alcohol dehydrogenase level during mixed wine fermentation.

    Science.gov (United States)

    Milanovic, Vesna; Ciani, Maurizio; Oro, Lucia; Comitini, Francesca

    2012-02-03

    The use of a multistarter fermentation process with Saccharomyces cerevisiae and non-Saccharomyces wine yeasts has been proposed to simulate natural must fermentation and to confer greater complexity and specificity to wine. In this context, the combined use of S. cerevisiae and immobilized Starmerella bombicola cells (formerly Candida stellata) was assayed to enhance glycerol concentration, reduce ethanol content and to improve the analytical composition of wine. In order to investigate yeast metabolic interaction during controlled mixed fermentation and to evaluate the influence of S. bombicola on S. cerevisiae, the gene expression and enzymatic activity of two key enzymes of the alcoholic fermentation pathway such as pyruvate decarboxylase (Pdc1) and alcohol dehydrogenase (Adh1) were studied. The presence of S. bombicola immobilized cells in a mixed fermentation trial confirmed an increase in fermentation rate, a combined consumption of glucose and fructose, an increase in glycerol and a reduction in the production of ethanol as well as a modification in the fermentation of by products. The alcoholic fermentation of S. cerevisiae was also influenced by S. bombicola immobilized cells. Indeed, Pdc1 activity in mixed fermentation was lower than that exhibited in pure culture while Adh1 activity showed an opposite behavior. The expression of both PDC1 and ADH1 genes was highly induced at the initial phase of fermentation. The expression level of PDC1 at the end of fermentation was much higher in pure culture while ADH1 level was similar in both pure and mixed fermentations. In mixed fermentation, S. bombicola immobilized cells greatly affected the fermentation behavior of S. cerevisiae and the analytical composition of wine. The influence of S. bombicola on S. cerevisiae was not limited to a simple additive contribution. Indeed, its presence caused metabolic modifications during S. cerevisiae fermentation causing variation in the gene expression and enzymatic

  4. Ethyl Pyruvate Preserves IGF-I Sensitivity toward mTOR Substrates and Protein Synthesis in C2C12 Myotubes

    Science.gov (United States)

    Frost, Robert A.; Pereyra, Erika; Lang, Charles H.

    2011-01-01

    Bacterial infection decreases skeletal muscle protein synthesis via inhibition of the mammalian target of rapamycin (mTOR), a key regulator of translation initiation. To better define the mechanism by which muscle mTOR activity is decreased, we used an in vitro model of C2C12 myotubes treated with endotoxin [lipopolysaccharide (LPS)]and interferon (IFN)-γ to determine whether stable lipophilic pyruvate derivatives restore mTOR signaling. Myotubes treated with a combination of LPS and IFNγ down-regulated the phosphorylation of the mTOR substrates S6 kinase-1 and 4E binding protein-1. The phosphorylation of ribosomal protein S6 was decreased, whereas phosphorylation of elongation factor-2 was enhanced; all results consistent with defects in both translation initiation and elongation. LPS/IFNγ decreased protein synthesis 60% in myotubes. Treatment with methyl or ethyl pyruvate partially protected against the LPS/IFNγ-induced fall in mTOR signaling. The protective effect of ethyl and methyl pyruvate could not be replicated by an equimolar amount of sodium pyruvate. Although LPS/IFNγ treated myotubes were initially IGF-I responsive, prolonged exposure (≥17 h) resulted in IGF-I resistance at the level of mTOR despite normal IGF-I receptor phosphorylation. Ethyl pyruvate treatment restored IGF-I sensitivity as evidenced by the left shift in the IGF-I dose-response curve and maintained IGF-I responsiveness for a prolonged period of time. Ethyl pyruvate also restored IGF-I-stimulated protein synthesis in LPS/IFNγ-treated myotubes. Cotreatment with N-acetyl cysteine or ascorbic acid also preserved IGF-I sensitivity and mTOR activity. The data suggest that the combination of LPS and IFNγ inhibits mTOR activity and that prolonged exposure induces IGF-I resistance in myotubes. Lipophilic pyruvate derivatives and antioxidants show promise at rescuing mTOR activity and muscle protein synthesis by maintaining IGF-I sensitivity in this model. PMID:21106878

  5. Metabolic compartmentalization in the human cortex and hippocampus: evidence for a cell- and region-specific localization of lactate dehydrogenase 5 and pyruvate dehydrogenase

    Directory of Open Access Journals (Sweden)

    Kovari Enikö

    2007-05-01

    Full Text Available Abstract Background For a long time now, glucose has been thought to be the main, if not the sole substrate for brain energy metabolism. Recent data nevertheless suggest that other molecules, such as monocarboxylates (lactate and pyruvate mainly could be suitable substrates. Although monocarboxylates poorly cross the blood brain barrier (BBB, such substrates could replace glucose if produced locally. The two key enzymatiques systems required for the production of these monocarboxylates are lactate dehydrogenase (LDH; EC1.1.1.27 that catalyses the interconversion of lactate and pyruvate and the pyruvate dehydrogenase complex that irreversibly funnels pyruvate towards the mitochondrial TCA and oxydative phosphorylation. Results In this article, we show, with monoclonal antibodies applied to post-mortem human brain tissues, that the typically glycolytic isoenzyme of lactate dehydrogenase (LDH-5; also called LDHA or LDHM is selectively present in astrocytes, and not in neurons, whereas pyruvate dehydrogenase (PDH is mainly detected in neurons and barely in astrocytes. At the regional level, the distribution of the LDH-5 immunoreactive astrocytes is laminar and corresponds to regions of maximal 2-deoxyglucose uptake in the occipital cortex and hippocampus. In hippocampus, we observed that the distribution of the oxidative enzyme PDH was enriched in the neurons of the stratum pyramidale and stratum granulosum of CA1 through CA4, whereas the glycolytic enzyme LDH-5 was enriched in astrocytes of the stratum moleculare, the alveus and the white matter, revealing not only cellular, but also regional, selective distributions. The fact that LDH-5 immunoreactivity was high in astrocytes and occurred in regions where the highest uptake of 2-deoxyglucose was observed suggests that glucose uptake followed by lactate production may principally occur in these regions. Conclusion These observations reveal a metabolic segregation, not only at the cellular but also

  6. Pyruvate dehydrogenase complex regulator (PdhR) gene deletion boosts glucose metabolism in Escherichia coli under oxygen-limited culture conditions.

    Science.gov (United States)

    Maeda, Soya; Shimizu, Kumiko; Kihira, Chie; Iwabu, Yuki; Kato, Ryuichi; Sugimoto, Makoto; Fukiya, Satoru; Wada, Masaru; Yokota, Atsushi

    2017-04-01

    Pyruvate dehydrogenase complex regulator (PdhR) is a transcriptional regulator that negatively regulates formation of pyruvate dehydrogenase complex (PDHc), NADH dehydrogenase (NDH)-2, and cytochrome bo 3 oxidase in Escherichia coli. To investigate the effects of a PdhR defect on glucose metabolism, a pdhR deletion mutant was derived from the wild-type E. coli W1485 strain by λ Red-mediated recombination. While no difference in the fermentation profiles was observed between the two strains under oxygen-sufficient conditions, under oxygen-limited conditions, the growth level of the wild-type strain was significantly decreased with retarded glucose consumption accompanied by by-production of substantial amounts of pyruvic acid and acetic acid. In contrast, the mutant grew and consumed glucose more efficiently than did the wild-type strain with enhanced respiration, little by-production of pyruvic acid, less production yield and rates of acetic acid, thus displaying robust metabolic activity. As expected, increased activities of PDHc and NDH-2 were observed in the mutant. The increased activity of PDHc may explain the loss of pyruvic acid by-production, probably leading to decreased acetic acid formation, and the increased activity of NDH-2 may explain the enhanced respiration. Measurement of the intracellular NAD + /NADH ratio in the mutant revealed more oxidative or more reductive intracellular environments than those in the wild-type strain under oxygen-sufficient and -limited conditions, respectively, suggesting another role of PdhR: maintaining redox balance in E. coli. The overall results demonstrate the biotechnological advantages of pdhR deletion in boosting glucose metabolism and also improve our understanding of the role of PdhR in bacterial physiology. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. The Danish St. Croix Project

    DEFF Research Database (Denmark)

    J. Douma, Michael; Rasmussen, Anders Bo

    2014-01-01

    Working from previously unknown sources in Danish archives, this article establishes for the first time the important role that the island of St. Croix played in the Lincoln Administration’s considerations on colonizing African Americans abroad. The paper argues that U.S. Secretary of State Willi...... H. Seward, commonly viewed as an anti-colonizationist, was at least a mild proponent of colonization in its earliest stages. The paper demonstrates further that in the summer of 1862 the St. Croix colonization project was an important stepping stone in the Lincoln administration’s legal...

  8. Análise morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus da pré-puberdade até a pós-puberdade

    Directory of Open Access Journals (Sweden)

    Amanda K.R. Nunes

    2013-12-01

    Full Text Available Este estudo descreveu as análises morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus de cinco (S5; seis (S6; nove (S9 e onze (S11 semanas de idade (N=5/grupo. Os aspectos analisados incluíram a contagem das populações celulares presentes no estádio 1 do ciclo do epitélio seminífero (CES, eficiência das mitoses espermatogoniais (RMi, produção meiótica (RMe, rendimento geral da espermatogênese (RGE, índice de células de Sertoli (ICS e capacidade de suporte das células de Sertoli (CSCS. Os resultados mostraram que número médio de espermatogônias A, espermatócitos primários em pré-leptóteno/leptóteno, espermatócitos primários em paquíteno, células espermatogênicas totais e células de Sertoli mostraram variações numéricas em função da idade, entretanto, não detectadas estatisticamente, enquanto espermátides arredondadas aumentaram significativamente na puberdade e depois se estabilizaram. A produção espermatogênica de cobaios de 5 a 11 semanas não atingiu o ponto de estabilização e o RMi, RMe, RGE, ICS e CSCS mostraram variação numérica significativa em função da idade. Os resultados demonstraram que Cavia porcellus na pós-puberdade 2 são um modelo experimental vantajoso para estudos de processos de reconhecimento homólogos, alinhamento, e sinapses durante a prófase meiótica; o rendimento intrínseco da espermatogênese em cobaios é semelhante ao relatado para ratos Wistar, pacas e cutias (Dasyprocta sp. e menor do que em preás, enquanto que a eficiência funcional das células de Sertoli é superior a de cutias e ratos Wistar e inferior à de pacas, rato espinhoso e catetos. Concluiu-se que em cobaios a espermatogênese está completamente estabelecida na semana 6 de idade, indicando a fase púbere do desenvolvimento sexual, e até a semana 11 eles não atingiram a produção espermática diária máxima e, portanto, a maturidade sexual.

  9. Efecto de la harina de hojas de Erythrina sp. sobre el perfil bioquímico, parámetros biológicos e histopatología del hígado de Cavia porcellus

    Directory of Open Access Journals (Sweden)

    Daniel Paredes - López

    2017-01-01

    Full Text Available El objetivo de este estudio fue determinar el efecto de la harina de hojas de Erythrina sobre los perfiles bioquímicos, parámetros biológicos y tejido hepático de Cavia porcellus . S e utilizaron 75 cuyes machos de 13 días de edad, formándose 5 grupos experimentales con tres repeticiones cada uno. Todos se alimentaron con 100 g/día de King grass y alimento balanceado para cuyes ad libitum . Las hojas con peciolo se secaron y se molturar on a 1 mm de diámetro. La sangre se obtuvo a los 75 días de edad de la vena safena lateral y en suero sanguíneo se determinó perfiles de glucosa, proteína total, albumina, aspartato aminotrasferasa, alanino aminotransferasa, lactato deshidrogenasa y urea. Trozos de hígado se procesaron hasta obtener los cortes histológicos. Los perfiles de proteína total y albumina mostraron regresión lineal positiva (p < 0,05, el rendimiento de carcasa regresión lineal negativa (p < 0,05 y la estructura histológica del h ígado no tuvo cambios a medida que incrementó el nivel de harina de Erytrhina en la ración. La Erythrina causó una respuesta contrastante entre los perfiles de proteína total y albumina en sangre y el rendimiento de carcasa y no causó alteración estructura l del hígado.

  10. 1st quarterly report 1977

    International Nuclear Information System (INIS)

    1977-06-01

    The present report describes the activities carried out in the 1st quarter of 1977 at the Gesellschaft fuer Kernforschung in Karlsruhe or on its behalf in the framework of the fast breeder project (PSB). The problems and main results of the partial projects fuel rod development, materials testing, reactor physics, reactor safety and reactor technology are presented. (RW) [de

  11. Methylphenidatinduceret ST-elevations-myokardieinfarkt

    DEFF Research Database (Denmark)

    Ruwald, Martin Huth; Ruwald, Anne-Christine Huth; Tønder, Niels

    2012-01-01

    Adult attention deficit and hyperkinetic disorder (ADHD) is increasingly diagnosed and treated with methylphenidate. We present the case of an 20 year-old man, who was diagnosed with ADHD and suffered a ST elevation acute myocardial infarction due to coronary vasospasm related to an overdose...

  12. Investigation of the biosynthesis of acetyl-CoA and oxaloacetic acid from pyruvic acid and the quantitative evaluation of incorporated 13C-labeled l-alanine in Arthrobacter hyalinus

    International Nuclear Information System (INIS)

    Katsumi Iida

    2014-01-01

    Studies on the contribution to acetyl-CoA and oxaloacetic acid from the pyruvic acid transformation from l-alanine in Arthrobacter hyalinus were conducted by means of feeding experiments with l-[1- 13 C]alanine and l-[3- 13 C]alanine, followed by an analysis of the labeling patterns of coproporphyrinogen III using 13 C NMR spectroscopy. The results demonstrated that l-alanine was transformed via pyruvic acid to both acetyl-CoA and oxaloacetic acid. Additionally, the quantitative analysis indicated that pyruvic acid was transformed to acetyl-CoA and oxaloacetic acid in the ratio of 1:0.8. (author)

  13. Engineering acetyl coenzyme A supply: functional expression of a bacterial pyruvate dehydrogenase complex in the cytosol of Saccharomyces cerevisiae.

    Science.gov (United States)

    Kozak, Barbara U; van Rossum, Harmen M; Luttik, Marijke A H; Akeroyd, Michiel; Benjamin, Kirsten R; Wu, Liang; de Vries, Simon; Daran, Jean-Marc; Pronk, Jack T; van Maris, Antonius J A

    2014-10-21

    The energetic (ATP) cost of biochemical pathways critically determines the maximum yield of metabolites of vital or commercial relevance. Cytosolic acetyl coenzyme A (acetyl-CoA) is a key precursor for biosynthesis in eukaryotes and for many industrially relevant product pathways that have been introduced into Saccharomyces cerevisiae, such as isoprenoids or lipids. In this yeast, synthesis of cytosolic acetyl-CoA via acetyl-CoA synthetase (ACS) involves hydrolysis of ATP to AMP and pyrophosphate. Here, we demonstrate that expression and assembly in the yeast cytosol of an ATP-independent pyruvate dehydrogenase complex (PDH) from Enterococcus faecalis can fully replace the ACS-dependent pathway for cytosolic acetyl-CoA synthesis. In vivo activity of E. faecalis PDH required simultaneous expression of E. faecalis genes encoding its E1α, E1β, E2, and E3 subunits, as well as genes involved in lipoylation of E2, and addition of lipoate to growth media. A strain lacking ACS that expressed these E. faecalis genes grew at near-wild-type rates on glucose synthetic medium supplemented with lipoate, under aerobic and anaerobic conditions. A physiological comparison of the engineered strain and an isogenic Acs(+) reference strain showed small differences in biomass yields and metabolic fluxes. Cellular fractionation and gel filtration studies revealed that the E. faecalis PDH subunits were assembled in the yeast cytosol, with a subunit ratio and enzyme activity similar to values reported for PDH purified from E. faecalis. This study indicates that cytosolic expression and assembly of PDH in eukaryotic industrial microorganisms is a promising option for minimizing the energy costs of precursor supply in acetyl-CoA-dependent product pathways. Importance: Genetically engineered microorganisms are intensively investigated and applied for production of biofuels and chemicals from renewable sugars. To make such processes economically and environmentally sustainable, the energy

  14. Inhibiting sperm pyruvate dehydrogenase complex and its E3 subunit, dihydrolipoamide dehydrogenase affects fertilization in Syrian hamsters.

    Directory of Open Access Journals (Sweden)

    Archana B Siva

    Full Text Available BACKGROUND/AIMS: The importance of sperm capacitation for mammalian fertilization has been confirmed in the present study via sperm metabolism. Involvement of the metabolic enzymes pyruvate dehydrogenase complex (PDHc and its E3 subunit, dihydrolipoamide dehydrogenase (DLD in hamster in vitro fertilization (IVF via in vitro sperm capacitation is being proposed through regulation of sperm intracellular lactate, pH and calcium. METHODOLOGY AND PRINCIPAL FINDINGS: Capacitated hamster spermatozoa were allowed to fertilize hamster oocytes in vitro which were then assessed for fertilization, microscopically. PDHc/DLD was inhibited by the use of the specific DLD-inhibitor, MICA (5-methoxyindole-2-carboxylic acid. Oocytes fertilized with MICA-treated (MT [and thus PDHc/DLD-inhibited] spermatozoa showed defective fertilization where 2nd polar body release and pronuclei formation were not observed. Defective fertilization was attributable to capacitation failure owing to high lactate and low intracellular pH and calcium in MT-spermatozoa during capacitation. Moreover, this defect could be overcome by alkalinizing spermatozoa, before fertilization. Increasing intracellular calcium in spermatozoa pre-IVF and in defectively-fertilized oocytes, post-fertilization rescued the arrest seen, suggesting the role of intracellular calcium from either of the gametes in fertilization. Parallel experiments carried out with control spermatozoa capacitated in medium with low extracellular pH or high lactate substantiated the necessity of optimal sperm intracellular lactate levels, intracellular pH and calcium during sperm capacitation, for proper fertilization. CONCLUSIONS: This study confirms the importance of pyruvate/lactate metabolism in capacitating spermatozoa for successful fertilization, besides revealing for the first time the importance of sperm PDHc/ DLD in fertilization, via the modulation of sperm intracellular lactate, pH and calcium during capacitation. In

  15. Inhibiting Sperm Pyruvate Dehydrogenase Complex and Its E3 Subunit, Dihydrolipoamide Dehydrogenase Affects Fertilization in Syrian Hamsters

    Science.gov (United States)

    Sailasree, Purnima; Singh, Durgesh K.; Kameshwari, Duvurri B.; Shivaji, Sisinthy

    2014-01-01

    Background/Aims The importance of sperm capacitation for mammalian fertilization has been confirmed in the present study via sperm metabolism. Involvement of the metabolic enzymes pyruvate dehydrogenase complex (PDHc) and its E3 subunit, dihydrolipoamide dehydrogenase (DLD) in hamster in vitro fertilization (IVF) via in vitro sperm capacitation is being proposed through regulation of sperm intracellular lactate, pH and calcium. Methodology and Principal Findings Capacitated hamster spermatozoa were allowed to fertilize hamster oocytes in vitro which were then assessed for fertilization, microscopically. PDHc/DLD was inhibited by the use of the specific DLD-inhibitor, MICA (5-methoxyindole-2-carboxylic acid). Oocytes fertilized with MICA-treated (MT) [and thus PDHc/DLD-inhibited] spermatozoa showed defective fertilization where 2nd polar body release and pronuclei formation were not observed. Defective fertilization was attributable to capacitation failure owing to high lactate and low intracellular pH and calcium in MT-spermatozoa during capacitation. Moreover, this defect could be overcome by alkalinizing spermatozoa, before fertilization. Increasing intracellular calcium in spermatozoa pre-IVF and in defectively-fertilized oocytes, post-fertilization rescued the arrest seen, suggesting the role of intracellular calcium from either of the gametes in fertilization. Parallel experiments carried out with control spermatozoa capacitated in medium with low extracellular pH or high lactate substantiated the necessity of optimal sperm intracellular lactate levels, intracellular pH and calcium during sperm capacitation, for proper fertilization. Conclusions This study confirms the importance of pyruvate/lactate metabolism in capacitating spermatozoa for successful fertilization, besides revealing for the first time the importance of sperm PDHc/ DLD in fertilization, via the modulation of sperm intracellular lactate, pH and calcium during capacitation. In addition, the

  16. Team Danmarks støttekoncept

    DEFF Research Database (Denmark)

    Storm, Rasmus K.

    Evaluering af Team Danmarks støttekoncept 2005-2008 med omfattende analyser af Team Danmarks virke, dets støttekoncept og de samarbejdsrelationer med specialforbund, udøvere, politisk valgte ledere, trænere mv., som udmøntningen af støttekonceptet forudsætter. Herunder analyse af...

  17. Pyruvate-sensitive AOX exists as a non-covalently associated dimer in the homeothermic spadix of the skunk cabbage, Symplocarpus renifolius.

    Science.gov (United States)

    Onda, Yoshihiko; Kato, Yoshiaki; Abe, Yukie; Ito, Takanori; Ito-Inaba, Yasuko; Morohashi, Miyuki; Ito, Yuka; Ichikawa, Megumi; Matsukawa, Kazushige; Otsuka, Minoru; Koiwa, Hiroyuki; Ito, Kikukatsu

    2007-12-22

    The cyanide-resistant alternative oxidase (AOX) is a homodimeric protein whose activity can be regulated by the oxidation/reduction state and by alpha-keto acids. To further clarify the role of AOX in the skunk cabbage, Symplocarpus renifolius, we have performed expression and functional analyses of the encoding gene. Among the various tissues in the skunk cabbage, SrAOX transcripts were found to be specifically expressed in the thermogenic spadix. Moreover, our data demonstrate that the SrAOX protein exists as a non-covalently associated dimer in the thermogenic spadix, and is more sensitive to pyruvate than to other carboxylic acids. Our results suggest that the pyruvate-mediated modification of SrAOX activity plays a significant role in thermoregulation in the skunk cabbage.

  18. Effect of L-carnitine and pyruvate on equine sperm maintained at 5 ºC and 15 ºC during 24 h: preliminary results

    Directory of Open Access Journals (Sweden)

    Avila G

    2016-12-01

    Full Text Available The aim of this study was to evaluate if the addition of L-carnitine and pyruvate to two semen transport extenders (Kenney and Kenney modified by Tyrodes is able to maintain sperm parameters for 24 h at 5 ºC and 15 ºC. Semen was obtained from 3 stallions (n=3; r=2 and at time 0 and after 24 h of cooling, the following parameters evaluated: total and progressive motility (CASA, viability and acrosome status (FITC-PNA-PI, membrane function (HOS, and DNA with Toluidine Blue stain (TB and the Sperm Chromatin Dispersion assay (SCD. Each temperature was individually analyzed using a factorial design with a 5% significance level. No interactions were observed. For the moment, the Kenney extender with the addition of L-carnitine and pyruvate showed the best results for maintaining most sperm parameters for 24 h at both 5 ºC and 15 ºC.

  19. Amsterdam - St. Paul Hotspot History

    OpenAIRE

    Janin, Myriam; Hémond, Christophe,; Maia, Marcia

    2010-01-01

    The Amsterdam St. Paul hotspot (Indian Ocean) interacts with a regional depleted mantle containing some DUPAL-like blobs. Its lateral motion velocity is about 1-2 cm/yr. The plume induced the construction of a volcanic chain and of an oceanic plateau through two pulses of more intense magmatic activity. The intraplate plate activity appears partially controlled by some tectonic stress induced by the diverging motion of the Australian and Capricorn plates along a diffuse boundary.

  20. Molecular modeling on pyruvate phosphate dikinase of Entamoeba histolytica and in silico virtual screening for novel inhibitors.

    Science.gov (United States)

    Stephen, Preyesh; Vijayan, Ramachandran; Bhat, Audesh; Subbarao, N; Bamezai, R N K

    2008-09-01

    Pyruvate phosphate dikinase (PPDK) is the key enzyme essential for the glycolytic pathway in most common and perilous parasite Entamoeba histolytica. Inhibiting the function of this enzyme could control the wide spread of intestinal infections caused by Entamoeba histolytica in humans. With this objective, we modeled the three dimensional structure of the PPDK protein. We used templates with 51% identity and 67% similarity to employ homology-modeling approach. Stereo chemical quality of protein structure was validated by protein structure validation program PROCHECK and VERIFY3D. Experimental proof available in literature along with the in silico studies indicated Lys21, Arg91, Asp323, Glu325 and Gln337 to be the probable active sites in the target protein. Virtual screening was carried out using the genetic docking algorithm GOLD and a consensus scoring function X-Score to substantiate the prediction. The small molecule libraries (ChemDivision database, Diversity dataset, Kinase inhibitor database) were used for screening process. Along with the high scoring results, the interaction studies provided promising ligands for future experimental screening to inhibit the function of PPDK in Entamoeba histolytica. Further, the phylogeny study was carried out to assess the possibility of using the proposed ligands as inhibitors in related pathogens.

  1. In silico screening, genotyping, molecular dynamics simulation and activity studies of SNPs in pyruvate kinase M2.

    Directory of Open Access Journals (Sweden)

    Ponnusamy Kalaiarasan

    Full Text Available Role of, 29-non-synonymous, 15-intronic, 3-close to UTR, single nucleotide polymorphisms (SNPs and 2 mutations of Human Pyruvate Kinase (PK M2 were investigated by in-silico and in-vitro functional studies. Prediction of deleterious substitutions based on sequence homology and structure based servers, SIFT, PANTHER, SNPs&GO, PhD-SNP, SNAP and PolyPhen, depicted that 19% emerged common between all the mentioned programs. SNPeffect and HOPE showed three substitutions (C31F, Q310P and S437Y in-silico as deleterious and functionally important. In-vitro activity assays showed C31F and S437Y variants of PKM2 with reduced activity, while Q310P variant was catalytically inactive. The allosteric activation due to binding of fructose 1-6 bisphosphate (FBP was compromised in case of S437Y nsSNP variant protein. This was corroborated through molecular dynamics (MD simulation study, which was also carried out in other two variant proteins. The 5 intronic SNPs of PKM2, associated with sporadic breast cancer in a case-control study, when subjected to different computational analyses, indicated that 3 SNPs (rs2856929, rs8192381 and rs8192431 could generate an alternative transcript by influencing splicing factor binding to PKM2. We propose that these, potentially functional and important variations, both within exons and introns, could have a bearing on cancer metabolism, since PKM2 has been implicated in cancer in the recent past.

  2. Pyruvic oxime nitrification and copper and nickel resistance by a Cupriavidus pauculus, an active heterotrophic nitrifier-denitrifier.

    Science.gov (United States)

    Ramirez, Miguel; Obrzydowski, Jennifer; Ayers, Mary; Virparia, Sonia; Wang, Meijing; Stefan, Kurtis; Linchangco, Richard; Castignetti, Domenic

    2014-01-01

    Heterotrophic nitrifiers synthesize nitrogenous gasses when nitrifying ammonium ion. A Cupriavidus pauculus, previously thought an Alcaligenes sp. and noted as an active heterotrophic nitrifier-denitrifier, was examined for its ability to produce nitrogen gas (N2) and nitrous oxide (N2O) while heterotrophically nitrifying the organic substrate pyruvic oxime [CH3-C(NOH)-COOH]. Neither N2 nor N2O were produced. Nucleotide and phylogenetic analyses indicated that the organism is a member of a genus (Cupriavidus) known for its resistance to metals and its metabolism of xenobiotics. The microbe (a Cupriavidus pauculus designated as C. pauculus strain UM1) was examined for its ability to perform heterotrophic nitrification in the presence of Cu(2+) and Ni(2+) and to metabolize the xenobiotic phenol. The bacterium heterotrophically nitrified well when either 1 mM Cu(2+) or 0.5 mM Ni(2+) was present in either enriched or minimal medium. The organism also used phenol as a sole carbon source in either the presence or absence of 1 mM Cu(2+) or 0.5 mM Ni(2+). The ability of this isolate to perform a number of different metabolisms, its noteworthy resistance to copper and nickel, and its potential use as a bioremediation agent are discussed.

  3. Pyruvic Oxime Nitrification and Copper and Nickel Resistance by a Cupriavidus pauculus, an Active Heterotrophic Nitrifier-Denitrifier

    Directory of Open Access Journals (Sweden)

    Miguel Ramirez

    2014-01-01

    Full Text Available Heterotrophic nitrifiers synthesize nitrogenous gasses when nitrifying ammonium ion. A Cupriavidus pauculus, previously thought an Alcaligenes sp. and noted as an active heterotrophic nitrifier-denitrifier, was examined for its ability to produce nitrogen gas (N2 and nitrous oxide (N2O while heterotrophically nitrifying the organic substrate pyruvic oxime [CH3–C(NOH–COOH]. Neither N2 nor N2O were produced. Nucleotide and phylogenetic analyses indicated that the organism is a member of a genus (Cupriavidus known for its resistance to metals and its metabolism of xenobiotics. The microbe (a Cupriavidus pauculus designated as C. pauculus strain UM1 was examined for its ability to perform heterotrophic nitrification in the presence of Cu2+ and Ni2+ and to metabolize the xenobiotic phenol. The bacterium heterotrophically nitrified well when either 1 mM Cu2+ or 0.5 mM Ni2+ was present in either enriched or minimal medium. The organism also used phenol as a sole carbon source in either the presence or absence of 1 mM Cu2+ or 0.5 mM Ni2+. The ability of this isolate to perform a number of different metabolisms, its noteworthy resistance to copper and nickel, and its potential use as a bioremediation agent are discussed.

  4. Evaluation of hyperpolarized [1-¹³C]-pyruvate by magnetic resonance to detect ionizing radiation effects in real time.

    Directory of Open Access Journals (Sweden)

    Vlad C Sandulache

    Full Text Available Ionizing radiation (IR cytotoxicity is primarily mediated through reactive oxygen species (ROS. Since tumor cells neutralize ROS by utilizing reducing equivalents, we hypothesized that measurements of reducing potential using real-time hyperpolarized (HP magnetic resonance spectroscopy (MRS and spectroscopic imaging (MRSI can serve as a surrogate marker of IR induced ROS. This hypothesis was tested in a pre-clinical model of anaplastic thyroid carcinoma (ATC, an aggressive head and neck malignancy. Human ATC cell lines were utilized to test IR effects on ROS and reducing potential in vitro and [1-¹³C] pyruvate HP-MRS/MRSI imaging of ATC orthotopic xenografts was used to study in vivo effects of IR. IR increased ATC intra-cellular ROS levels resulting in a corresponding decrease in reducing equivalent levels. Exogenous manipulation of cellular ROS and reducing equivalent levels altered ATC radiosensitivity in a predictable manner. Irradiation of ATC xenografts resulted in an acute drop in reducing potential measured using HP-MRS, reflecting the shunting of reducing equivalents towards ROS neutralization. Residual tumor tissue post irradiation demonstrated heterogeneous viability. We have adapted HP-MRS/MRSI to non-invasively measure IR mediated changes in tumor reducing potential in real time. Continued development of this technology could facilitate the development of an adaptive clinical algorithm based on real-time adjustments in IR dose and dose mapping.

  5. Pyruvate kinase M2 overexpression and poor prognosis in solid tumors of digestive system: evidence from 16 cohort studies.

    Science.gov (United States)

    Wu, Jiayuan; Hu, Liren; Chen, Manyu; Cao, Wenjun; Chen, Haicong; He, Taiping

    2016-01-01

    The expression of pyruvate kinase M2 (PKM2) has been linked to tumor formation and invasion. Specifically, the relationship between high PKM2 expression and prognosis has been evaluated in solid tumors of digestive system. However, the prognostic value of PKM2 remains controversial. A literature search of PubMed, Embase, and Cochrane databases was conducted until October 2015. The end point focused on overall survival (OS). The pooled hazard ratio (HR) or odds ratio and the 95% confidence intervals were calculated to correlate PKM2 overexpression with OS and clinicopathological characteristics by employing fixed- or random-effects models, depending on the heterogeneity of the included studies. We identified 18 cohorts in 16 studies involving 2,812 patients for this meta-analysis. Overall, the combined HR for OS in all tumor types was 1.74 (1.44-2.11; Pdigestive system, thereby suggesting that PKM2 might be an indicator of poor prognosis in digestive system cancers.

  6. Preventing intraperitoneal adhesions with ethyl pyruvate and hyaluronic acid/carboxymethylcellulose: a comparative study in an experimental model.

    Science.gov (United States)

    Caglayan, E Kıyak; Caglayan, K; Erdogan, N; Cinar, H; Güngör, B

    2014-10-01

    To compare the effectiveness of ethyl pyruvate (EP) with that of hyaluronic acid+carboxymethyl cellulose (Seprafilm) for the prevention of intraperitoneal adhesions. Seprafilm has been shown to be effective in many experimental and clinical studies. Thirty rats were divided into three groups at random, and uterine horn abrasion was performed by laparotomy. One group received no treatment (control group), one group received a single intraperitoneal dose of EP 50mg/kg (EP group), and a 2×1-cm patch of Seprafilm was applied in the third group (Seprafilm group). All rats were killed 14 days after surgery. Macroscopic and histopathological evaluation were performed by a surgeon and a pathologist who were blinded to group allocation. Histopathologically, inflammation, fibroblastic activity, foreign body reaction, collagen proliferation, vascular proliferation, Masson-Trichrome score, matrix metalloproteinase-2 score and vascular endothelial growth factor score were studied. Median macroscopic intraperitoneal adhesion scores for the control, EP and Seprafilm groups were 2.8, 1.2 and 1.1, respectively. Multiple comparisons between groups showed a significant difference (p0.05). After histopathological evaluation, significant differences in all parameters were found between the groups (p0.0167). In comparison with the untreated control group, EP and Seprafilm were found to reduce the formation of intraperitoneal adhesions. No significant difference was found between EP and Seprafilm. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Molecular modeling on pyruvate phosphate dikinase of Entamoeba histolytica and in silico virtual screening for novel inhibitors

    Science.gov (United States)

    Stephen, Preyesh; Vijayan, Ramachandran; Bhat, Audesh; Subbarao, N.; Bamezai, R. N. K.

    2008-09-01

    Pyruvate phosphate dikinase (PPDK) is the key enzyme essential for the glycolytic pathway in most common and perilous parasite Entamoeba histolytica. Inhibiting the function of this enzyme could control the wide spread of intestinal infections caused by Entamoeba histolytica in humans. With this objective, we modeled the three dimensional structure of the PPDK protein. We used templates with 51% identity and 67% similarity to employ homology-modeling approach. Stereo chemical quality of protein structure was validated by protein structure validation program PROCHECK and VERIFY3D. Experimental proof available in literature along with the in silico studies indicated Lys21, Arg91, Asp323, Glu325 and Gln337 to be the probable active sites in the target protein. Virtual screening was carried out using the genetic docking algorithm GOLD and a consensus scoring function X-Score to substantiate the prediction. The small molecule libraries (ChemDivision database, Diversity dataset, Kinase inhibitor database) were used for screening process. Along with the high scoring results, the interaction studies provided promising ligands for future experimental screening to inhibit the function of PPDK in Entamoeba histolytica. Further, the phylogeny study was carried out to assess the possibility of using the proposed ligands as inhibitors in related pathogens.

  8. Reciprocal Changes in Phosphoenolpyruvate Carboxykinase and Pyruvate Kinase with Age Are a Determinant of Aging in Caenorhabditis elegans.

    Science.gov (United States)

    Yuan, Yiyuan; Hakimi, Parvin; Kao, Clara; Kao, Allison; Liu, Ruifu; Janocha, Allison; Boyd-Tressler, Andrea; Hang, Xi; Alhoraibi, Hanna; Slater, Erin; Xia, Kevin; Cao, Pengxiu; Shue, Quinn; Ching, Tsui-Ting; Hsu, Ao-Lin; Erzurum, Serpil C; Dubyak, George R; Berger, Nathan A; Hanson, Richard W; Feng, Zhaoyang

    2016-01-15

    Aging involves progressive loss of cellular function and integrity, presumably caused by accumulated stochastic damage to cells. Alterations in energy metabolism contribute to aging, but how energy metabolism changes with age, how these changes affect aging, and whether they can be modified to modulate aging remain unclear. In locomotory muscle of post-fertile Caenorhabditis elegans, we identified a progressive decrease in cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C), a longevity-associated metabolic enzyme, and a reciprocal increase in glycolytic pyruvate kinase (PK) that were necessary and sufficient to limit lifespan. Decline in PEPCK-C with age also led to loss of cellular function and integrity including muscle activity, and cellular senescence. Genetic and pharmacologic interventions of PEPCK-C, muscle activity, and AMPK signaling demonstrate that declines in PEPCK-C and muscle function with age interacted to limit reproductive life and lifespan via disrupted energy homeostasis. Quantifications of metabolic flux show that reciprocal changes in PEPCK-C and PK with age shunted energy metabolism toward glycolysis, reducing mitochondrial bioenergetics. Last, calorie restriction countered changes in PEPCK-C and PK with age to elicit anti-aging effects via TOR inhibition. Thus, a programmed metabolic event involving PEPCK-C and PK is a determinant of aging that can be modified to modulate aging. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Regulation of pyruvate orthophosphate dikinase gene expression in C3 plants as compared to that in C4 plants

    International Nuclear Information System (INIS)

    Aoyagi, K.

    1985-01-01

    Pyruvate orthophosphate dikinase (PPDK) was found to be more widely distributed in both leaves and seeds of C 3 and C 4 plants than previously realized. Physicochemical and enzymic properties appear to be strongly conserved over this distribution. In wheat, a C 3 plant, both in seeds and leaves, the amount of PPDK protein is developmentally regulated. In seeds the enzyme level is determined by the level of PPDK mRNA. The role of PPDK seems to be providing phosphoenolpyruvate as a substrate for amino acid interconversions during development. In leaves, the PPDK protein level increased with development. PPDK is present in chloroplasts also in C 3 plants. In maize, a C 4 plant, PPDK is not limited to mesophyll cells but also is present in bundle sheath cells, kernels and other tissues. In the leaf, the appearance and accumulation of PPDK is well coordinated with other enzymes of carbon metabolism. In maize callus, a heterotrophic type PPDK is synthesized independently in light and is active in the dark. Shoot formation and establishment of autotrophy enhances the accumulation of the leaf-type PPDK and leaf-type isozymes of phosphoenolpyruvate carboxylase and NADP-malic enzyme. Ultrastructural changes and 14 C uptake patterns during regeneration of leaves from callus indicate that cell differentiation and Kranz anatomy are essential for the functional C 4 photosynthesis as well as for coordinated expression of enzymes involved in the C 4 pathway

  10. Increased Interstitial Concentrations of Glutamate and Pyruvate in Vastus Lateralis of Women with Fibromyalgia Syndrome Are Normalized after an Exercise Intervention - A Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Björn Gerdle

    Full Text Available Fibromyalgia syndrome (FMS is associated with central alterations, but controversies exist regarding the presence and role of peripheral factors. Microdialysis (MD can be used in vivo to study muscle alterations in FMS. Furthermore for chronic pain conditions such as FMS, the mechanisms for the positive effects of exercise are unclear. This study investigates the interstitial concentrations of algesics and metabolites in the vastus lateralis muscle of 29 women with FMS and 28 healthy women before and after an exercise intervention.All the participants went through a clinical examination and completed a questionnaire. In addition, their pressure pain thresholds (PPTs in their upper and lower extremities were determined. For both groups, MD was conducted in the vastus lateralis muscle before and after a 15-week exercise intervention of mainly resistance training of the lower limbs. Muscle blood flow and interstitial muscle concentrations of lactate, pyruvate, glutamate, glucose, and glycerol were determined.FMS was associated with significantly increased interstitial concentrations of glutamate, pyruvate, and lactate. After the exercise intervention, the FMS group exhibited significant decreases in pain intensity and in mean interstitial concentrations of glutamate, pyruvate, and glucose. The decrease in pain intensity in FMS correlated significantly with the decreases in pyruvate and glucose. In addition, the FMS group increased their strength and endurance.This study supports the suggestion that peripheral metabolic and algesic muscle alterations are present in FMS patients and that these alterations contribute to pain. After an exercise intervention, alterations normalized, pain intensity decreased (but not abolished, and strength and endurance improved, all findings that suggest the effects of exercise are partially peripheral.

  11. Flux control analysis of mitochondrial oxidative phosphorylation in rat skeletal muscle: pyruvate and palmitoyl-carnitine as substrates give different control patterns

    DEFF Research Database (Denmark)

    Fritzen, Anette J; Grunnet, Niels; Quistorff, Bjørn

    2007-01-01

    was associated with the ADP-generating system, i.e., 0.58 +/- 0.05 with pyruvate, but significantly lower, 0.40 +/- 0.05, with palmitoyl-carnitine as substrate. The flux control coefficients of complex I, III and IV, the ATP synthase, the ATP/ADP carrier and the P(i) carrier were 0.070 +/- 0.03, 0.083 +/- 0...

  12. Resistance imparted by traditional Chinese medicines to the acute change of glutamic pyruvic transaminase, alkaline phosphatase and creatine kinase activities in rat blood caused by noise.

    Science.gov (United States)

    Zhu, Bei-Wei; Sun, Yu-Mei; Yun, Xia; Han, Song; Piao, Mei-Lan; Murata, Yoshiyuki; Tada, Mikiro

    2004-05-01

    The activities of serum glutamic pyruvic transaminase (GPT), alkaline phosphatase (ALP) and creatine kinase (CK) in rats injected or not with the Chinese medicines, Astragali, Rhodiolae and Ligusticum, were determined after noise exposure. Noise at 95 and 105 dB significantly increased the activities of GPT, ALP and CK, and showed a dependence on the exposure time. The injection of each medicine significantly suppressed the increased enzyme activities by 95 and 105 dB noise.

  13. Preparation, characterization and thermal behaviour study of 4-dimethyl amino benzal pyruvate of lanthanides (III) and yttrium (III) in solid state

    International Nuclear Information System (INIS)

    Miyano, M.H.

    1990-01-01

    Solid state compounds involving Ln and DMBP, where Ln trivalent lanthanides (except promethium) and yttrium; DMBP 4-dimethyl amino benzylidene pyruvate, were prepared by addition of ligand to the corresponding metal ions chlorides, both in aqueous solution. The precipitates were washed with distilled water and dried at 40 0 C in a forced circulation oven. Complexometry with EDTA, thermogravimetry (TG), differential thermal analysis (DTA), infra-red absorption and X-ray diffraction have been used in the study of these compounds. (author)

  14. Lactate and Pyruvate Are Major Sources of Energy for Stallion Sperm with Dose Effects on Mitochondrial Function, Motility, and ROS Production.

    Science.gov (United States)

    Darr, Christa R; Varner, Dickson D; Teague, Sheila; Cortopassi, Gino A; Datta, Sandipan; Meyers, Stuart A

    2016-08-01

    Stallion sperm rely primarily on oxidative phosphorylation for production of ATP used in sperm motility and metabolism. The objective of the study was to identify which substrates included in Biggers, Whitten, and Whittingham (BWW) media are key to optimal mitochondrial function through measurements of sperm motility parameters, mitochondrial oxygen consumption, and cellular reactive oxygen species (ROS) production. It was expected that mitochondrial substrates, pyruvate and lactate, would support sperm motility and mitochondrial function better than the glycolytic substrate, glucose, due to direct utilization within the mitochondria. Measurements were performed after incubation in modified BWW media with varying concentrations of lactate, pyruvate, and glucose. The effects of media and duration of incubation on sperm motility, ROS production, and oxygen consumption were determined using a linear mixed-effects model. Duplicate ejaculates from four stallions were used in three separate experiments to determine the effects of substrate availability and concentration on sperm motility and mitochondrial function and the relationship of oxygen consumption with cellular ROS production. The present results indicate that lactate and pyruvate are the most important sources of energy for stallion sperm motility and velocity, and elicit a dose-dependent response. Additionally, lactate and pyruvate are ideal for maximal mitochondrial function, as sperm in these media operate at a very high level of their bioenergetic capability due to the high rate of energy metabolism. Moreover, we found that addition of glucose to the media is not necessary for short-term storage of equine sperm, and may even result in reduction of mitochondrial function. Finally, we have confirmed that ROS production can be the result of mitochondrial dysfunction as well as intense mitochondrial activity. © 2016 by the Society for the Study of Reproduction, Inc.

  15. Data regarding the growth of Lactobacillus acidophilus NCFM on different carbohydrates and recombinant production of elongation factor G and pyruvate kinase

    Directory of Open Access Journals (Sweden)

    Hasan Ufuk Celebioglu

    2017-10-01

    Full Text Available The present study describes the growth of the very well-known probiotic bacterium Lactobacillus acidophilus NCFM on different carbohydrates. Furthermore, recombinant production of putative moonlighting proteins elongation factor G and pyruvate kinase from this bacterium is described. For further and detailed interpretation of the data presented here, please see the research article “Mucin- and carbohydrate-stimulated adhesion and subproteome changes of the probiotic bacterium Lactobacillus acidophilus NCFM” (Celebioglu et al., 2017 [1].

  16. Data regarding the growth of Lactobacillus acidophilus NCFM on different carbohydrates and recombinant production of elongation factor G and pyruvate kinase

    DEFF Research Database (Denmark)

    Celebioglu, Hasan Ufuk; Olesen, Sita Vaag; Prehn, Kennie

    2017-01-01

    The present study describes the growth of the very well-known probiotic bacterium Lactobacillus acidophilus NCFM on different carbohydrates. Furthermore, recombinant production of putative moonlighting proteins elongation factor G and pyruvate kinase from this bacterium is described. For further ...... and detailed interpretation of the data presented here, please see the research article “Mucin- and carbohydrate-stimulated adhesion and subproteome changes of the probiotic bacterium Lactobacillus acidophilus NCFM” (Celebioglu et al., 2017) [1]....

  17. Effects of heavy ion irradiation, FSH/LH ratio and sodium pyruvate concentration on the in vitro maturation f sheep oocytes

    International Nuclear Information System (INIS)

    Chang Weihua; Zhang Yong; Xu Peng; Wu Haifeng; Wang Yanling; Zhang Hong

    2011-01-01

    This project evaluated the different effects of heavy-ion irradiation, the ratio of FSH/LH, and sodium pyruvate concentration on the in vitro maturation (IVM) sheep oocytes. Results showed that irradiation with 1.0 and 1.5 Gy could significantly improve IVM of sheep oocytes compared with the unirradiated control (p<0.05). Addition with 10 μg/ml FSH and 10 μg/ml LH (1 : 1, Ⅱ group) in the maturation medium resulted in the highest of IVM compared with Ⅰ group (1 : 2) , Ⅲ group (1 : 2) (p<0.05) and Ⅳ (5 : 1) group (p<0.01). IVM rate of the maturation medium with 0.2 g/L of sodium pyruvate was significantly higher than that with 0.1 g/L (p<0.05), 0.4 g/L (p<0.01), 0.6 g/L (p<0.01) and the control group (p<0.01). These data indicated that the heavy-ion irradiation to sheep oocytes with 1.0 and 1.5 Gy significantly promoted its maturation, and exposure to maturation medium with FSH and LH for 10 μg/ml (1 : 1) resulted in optimum maturity and the best maturing rate with 0.2 g/L of sodium pyruvate. (authors)

  18. In vivo 13C NMR study of the bidirectional reactions of the Wood-Werkman cycle and around the pyruvate node in Propionibacterium freudenreichii subsp. shermanii and Propionibacterium acidipropionici.

    Science.gov (United States)

    Deborde, C; Rolin, D B; Boyaval, P

    1999-10-01

    This study used in vitro 13C NMR spectroscopy to directly examine bidirectional reactions of the Wood-Werkman cycle involved in central carbon metabolic pathways of dairy propionibacteria during pyruvate catabolism. The flow of [2-13C]pyruvate label was monitored on living cell suspensions of Propionibacterium freudenreichii subsp. shermanii and Propionibacterium acidipropionici under acidic conditions. P. shermanii and P. acidipropionici cells consumed pyruvate at apparent initial rates of 161 and 39 micromol min(-1) g(-1) (cell dry weight), respectively. The bidirectionality of reactions in the first part of the Wood-Werkman cycle was evident from the formation of intermediates such as [3-13C]pyruvate and [3-13C]malate and of products like [2-13C]acetate from [2-13C]pyruvate. For the first time alanine labeled on C2 and C3 and aspartate labeled on C2 and C3 were observed during [2-13C]pyruvate metabolism by propionibacteria. The kinetics of aspartate isotopic enrichment was evidence for its production from oxaloacetate via aspartate aminotransferase. Activities of a partial tricarboxylic acid pathway, acetate synthesis, succinate synthesis, gluconeogenesis, aspartate synthesis, and alanine synthesis pathways were evident from the experimental results.

  19. Phosphate-Catalyzed Hydrogen Peroxide Formation from Agar, Gellan, and κ-Carrageenan and Recovery of Microbial Cultivability via Catalase and Pyruvate.

    Science.gov (United States)

    Kawasaki, Kosei; Kamagata, Yoichi

    2017-11-01

    Previously, we reported that when agar is autoclaved with phosphate buffer, hydrogen peroxide (H 2 O 2 ) is formed in the resulting medium (PT medium), and the colony count on the medium inoculated with environmental samples becomes much lower than that on a medium in which agar and phosphate are autoclaved separately (PS medium) (T. Tanaka et al., Appl Environ Microbiol 80:7659-7666, 2014, https://doi.org/10.1128/AEM.02741-14). However, the physicochemical mechanisms underlying this observation remain largely unknown. Here, we determined the factors affecting H 2 O 2 formation in agar. The H 2 O 2 formation was pH dependent: H 2 O 2 was formed at high concentrations in an alkaline or neutral phosphate buffer but not in an acidic buffer. Ammonium ions enhanced H 2 O 2 formation, implying the involvement of the Maillard reaction catalyzed by phosphate. We found that other gelling agents (e.g., gellan and κ-carrageenan) also produced H 2 O 2 after being autoclaved with phosphate. We then examined the cultivability of microorganisms from a fresh-water sample to test whether catalase and pyruvate, known as H 2 O 2 scavengers, are effective in yielding high colony counts. The colony count on PT medium was only 5.7% of that on PS medium. Catalase treatment effectively restored the colony count of PT medium (to 106% of that on PS medium). In contrast, pyruvate was not as effective as catalase: the colony count on sodium pyruvate-supplemented PT medium was 58% of that on PS medium. Given that both catalase and pyruvate can remove H 2 O 2 from PT medium, these observations indicate that although H 2 O 2 is the main cause of reduced colony count on PT medium, other unknown growth-inhibiting substances that cannot be removed by pyruvate (but can be by catalase) may also be involved. IMPORTANCE The majority of bacteria in natural environments are recalcitrant to laboratory culture techniques. Previously, we demonstrated that one reason for this is the formation of high H 2 O

  20. COMPARATIVE CHARACTERISTICS OF Co(II, Ni (II, Cu(II COORDINATION COMPOUNDS WITH SOME HYDRAZONES OF PYRUVIC ACID

    Directory of Open Access Journals (Sweden)

    A. V. Pulya

    2016-11-01

    Full Text Available Сonducted comparative analysis of the coordination compounds of Co2+, Ni2+, Cu2+ with condensation products of 2-(7-bromo-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-1-yl acetohydrazide – Hydazepam (Hydr, nicotinoyl- and isonicotinoyl hydrazones (H2N, H2I with pyruvic acid (HPv: [Co(HydrHPvCl2]·2H2O (I, [Ni(HydrPv2] (II, [Cu(HydrHPv (H2OCl2] (III, [CoCl(HNPv(H2O2] (IV, [CoCl(HIPv(H2O2] (V, [NiCl(HNPv(H2O2] (VI, [NiCl(HIPv(H2O2] (VII, [CuCl(HNPv]·H2O (VIII, [CuCl(HIPv]·H2O (IX. Complexes characterized by elemental analysis, IR spectroscopy, electrical conductivity, and magnetic susceptibility. Thermal stability of the complexes has been characterized. Structure of the coordination node of the complexes has been determined by EXAFS-spectroscopy. Regardless of composition, structure by heterocyclic nitrogen-containing moiety of the molecules HydrHPv, H2NРv, H2IРv formation of I-IX complexes is due to binding of complexing with a hydrazide functional group ketone form of the ligands. Ni2+ complexes II, VI, VII are different by composition (Ni2+:HydrHPv в II = 1:2, Ni2+:H2NРv(H2IРv в VI, VII = 1:1. Co2+, Cu2+ complexes with the same composition (M2+:ligand = 1:1. H2NPv, H2IPv in all complexes IV-IX – tridentate, occurs deprotonation and bonding carboxylate group НPv. HydrHPv coordinated to the Co2+, Cu2+ bidentate (I, III, without participation of the carboxylic group, and to the Ni2+ – tridentate (II.

  1. Half-sandwich rhodium(III) transfer hydrogenation catalysts: Reduction of NAD(+) and pyruvate, and antiproliferative activity.

    Science.gov (United States)

    Soldevila-Barreda, Joan J; Habtemariam, Abraha; Romero-Canelón, Isolda; Sadler, Peter J

    2015-12-01

    Organometallic complexes have the potential to behave as catalytic drugs. We investigate here Rh(III) complexes of general formula [(Cp(x))Rh(N,N')(Cl)], where N,N' is ethylenediamine (en), 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen) or N-(2-aminoethyl)-4-(trifluoromethyl)benzenesulfonamide (TfEn), and Cp(x) is pentamethylcyclopentadienyl (Cp*), 1-phenyl-2,3,4,5-tetramethylcyclopentadienyl (Cp(xPh)) or 1-biphenyl-2,3,4,5-tetramethyl cyclopentadienyl (Cp(xPhPh)). These complexes can reduce NAD(+) to NADH using formate as a hydride source under biologically-relevant conditions. The catalytic activity decreased in the order of N,N-chelated ligand bpy > phen > en with Cp* as the η(5)-donor. The en complexes (1-3) became more active with extension to the Cp(X) ring, whereas the activity of the phen (7-9) and bpy (4-6) compounds decreased. [Cp*Rh(bpy)Cl](+) (4) showed the highest catalytic activity, with a TOF of 37.4±2h(-1). Fast hydrolysis of the chlorido complexes 1-10 was observed by (1)H NMR (hydrogenation reactions was highly dependent on the nature of the chelating ligand and the Cp(x) ring. Competition reactions between NAD(+) and pyruvate for reduction by formate catalysed by 4 showed a preference for reduction of NAD(+). The antiproliferative activity of complex 3 towards A2780 human ovarian cancer cells increased by up to 50% when administered in combination with non-toxic doses of formate, suggesting that transfer hydrogenation can induce reductive stress in cancer cells. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Understanding the role of PknJ in Mycobacterium tuberculosis: biochemical characterization and identification of novel substrate pyruvate kinase A.

    Directory of Open Access Journals (Sweden)

    Gunjan Arora

    Full Text Available Reversible protein phosphorylation is a prevalent signaling mechanism which modulates cellular metabolism in response to changing environmental conditions. In this study, we focus on previously uncharacterized Mycobacterium tuberculosis Ser/Thr protein kinase (STPK PknJ, a putative transmembrane protein. PknJ is shown to possess autophosphorylation activity and is also found to be capable of carrying out phosphorylation on the artificial substrate myelin basic protein (MyBP. Previous studies have shown that the autophosphorylation activity of M. tuberculosis STPKs is dependent on the conserved residues in the activation loop. However, our results show that apart from the conventional conserved residues, additional residues in the activation loop may also play a crucial role in kinase activation. Further characterization of PknJ reveals that the kinase utilizes unusual ions (Ni(2+, Co(2+ as cofactors, thus hinting at a novel mechanism for PknJ activation. Additionally, as shown for other STPKs, we observe that PknJ possesses the capability to dimerize. In order to elucidate the signal transduction cascade emanating from PknJ, the M. tuberculosis membrane-associated protein fraction is treated with the active kinase and glycolytic enzyme Pyruvate kinase A (mtPykA is identified as one of the potential substrates of PknJ. The phospholabel is found to be localized on serine and threonine residue(s, with Ser(37 identified as one of the sites of phosphorylation. Since Pyk is known to catalyze the last step of glycolysis, our study shows that the fundamental pathways such as glycolysis can also be governed by STPK-mediated signaling.

  3. Skeletal Muscle Pyruvate Dehydrogenase Phosphorylation and Lactate Accumulation During Sprint Exercise in Normoxia and Severe Acute Hypoxia: Effects of Antioxidants

    Directory of Open Access Journals (Sweden)

    David Morales-Alamo

    2018-03-01

    Full Text Available Compared to normoxia, during sprint exercise in severe acute hypoxia the glycolytic rate is increased leading to greater lactate accumulation, acidification, and oxidative stress. To determine the role played by pyruvate dehydrogenase (PDH activation and reactive nitrogen and oxygen species (RNOS in muscle lactate accumulation, nine volunteers performed a single 30-s sprint (Wingate test on four occasions: two after the ingestion of placebo and another two following the intake of antioxidants, while breathing either hypoxic gas (PIO2 = 75 mmHg or room air (PIO2 = 143 mmHg. Vastus lateralis muscle biopsies were obtained before, immediately after, 30 and 120 min post-sprint. Antioxidants reduced the glycolytic rate without altering performance or VO2. Immediately after the sprints, Ser293- and Ser300-PDH-E1α phosphorylations were reduced to similar levels in all conditions (~66 and 91%, respectively. However, 30 min into recovery Ser293-PDH-E1α phosphorylation reached pre-exercise values while Ser300-PDH-E1α was still reduced by 44%. Thirty minutes after the sprint Ser293-PDH-E1α phosphorylation was greater with antioxidants, resulting in 74% higher muscle lactate concentration. Changes in Ser293 and Ser300-PDH-E1α phosphorylation from pre to immediately after the sprints were linearly related after placebo (r = 0.74, P < 0.001; n = 18, but not after antioxidants ingestion (r = 0.35, P = 0.15. In summary, lactate accumulation during sprint exercise in severe acute hypoxia is not caused by a reduced activation of the PDH. The ingestion of antioxidants is associated with increased PDH re-phosphorylation and slower elimination of muscle lactate during the recovery period. Ser293 re-phosphorylates at a faster rate than Ser300-PDH-E1α during the recovery period, suggesting slightly different regulatory mechanisms.

  4. Pyruvate carboxylase from Mycobacterium smegmatis: stabilization, rapid purification, molecular and biochemical characterization and regulation of the cellular level.

    Science.gov (United States)

    Mukhopadhyay, B; Purwantini, E

    2000-07-26

    This is the first report on the purification and characterization of an anaplerotic enzyme from a Mycobacterium. The anaplerotic reactions play important roles in the biochemical differentiation of mycobacteria into non-replicating stages. We have purified and characterized a pyruvate carboxylase (PYC) from Mycobacterium smegmatis and cloned and sequenced its gene. We have developed a very rapid and efficient purification protocol that provided PYC with very high specific activities (up to 150 U/mg) that remained essentially unchanged over a month. The enzyme was found to be a homomultimer of 121 kDa subunits, mildly thermophilic, absolutely dependent on acyl-CoAs for activity and inhibited by ADP, by excess Mg(2+), Co(2+), and Mn(2+), by aspartate, but not by glutamate and alpha-ketoglutarate. Supplementation of minimal growth medium with aspartate did not lower the cellular PYC level, rather doubled it; with glutamate the level remained unchanged. These observations would not fit the idea that the M. smegmatis enzyme fulfills a straightforward anaplerotic function; in a closely related organism, Corynebacterium glutamicum, PYC is the major anaplerotic enzyme. Growth on glucose provided 2-fold higher cellular PYC level than that observed with glycerol. The PYCs of M. smegmatis and Mycobacterium tuberculosis were highly homologous to each other. In M. smegmatis, M. tuberculosis and M. lepra, pyc was flanked by a putative methylase and a putative integral membrane protein genes in an identical operon-like arrangement. Thus, M. smegmatis could serve as a model for studying PYC-related physiological aspects of mycobacteria. Also, the ease of purification and the extraordinary stability could make the M. smegmatis enzyme a model for studying the structure-function relationships of PYCs in general. It should be noted that no crystal structure is available for this enzyme of paramount importance in all three domains of life, archaea, bacteria, and eukarya.

  5. H2S-induced S-sulfhydration of pyruvate carboxylase contributes to gluconeogenesis in liver cells.

    Science.gov (United States)

    Ju, YoungJun; Untereiner, Ashley; Wu, Lingyun; Yang, Guangdong

    2015-11-01

    Cystathionine gamma-lyase (CSE)-derived hydrogen sulfide (H(2)S) possesses diverse roles in the liver, affecting lipoprotein synthesis, insulin sensitivity, and mitochondrial biogenesis. H(2)S S-sulfhydration is now proposed as a major mechanism for H(2)S-mediated signaling. Pyruvate carboxylase (PC) is an important enzyme for gluconeogenesis. S-sulfhydration regulation of PC by H(2)S and its implication in gluconeogenesis in the liver have been unknown. Gene expressions were analyzed by real-time PCR and western blotting, and protein S-sulfhydration was assessed by both modified biotin switch assay and tag switch assay. Glucose production and PC activity was measured with coupled enzyme assays, respectively. Exogenously applied H(2)S stimulates PC activity and gluconeogenesis in both HepG2 cells and mouse primary liver cells. CSE overexpression enhanced but CSE knockout reduced PC activity and gluconeogenesis in liver cells, and blockage of PC activity abolished H(2)S-induced gluconeogenesis. H(2)S had no effect on the expressions of PC mRNA and protein, while H(2)S S-sulfhydrated PC in a dithiothreitol-sensitive way. PC S-sulfhydration was significantly strengthened by CSE overexpression but attenuated by CSE knockout, suggesting that H(2)S enhances glucose production through S-sulfhydrating PC. Mutation of cysteine 265 in human PC diminished H(2)S-induced PC S-sulfhydration and activity. In addition, high-fat diet feeding of mice decreased both CSE expression and PC S-sulfhydration in the liver, while glucose deprivation of HepG2 cells stimulated CSE expression. CSE/H(2)S pathway plays an important role in the regulation of glucose production through S-sulfhydrating PC in the liver. Tissue-specific regulation of CSE/H(2)S pathway might be a promising therapeutic target of diabetes and other metabolic syndromes. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Lack of consistent intracranial pressure pulse morphological changes during episodes of microdialysis lactate/pyruvate ratio increase

    International Nuclear Information System (INIS)

    Asgari, Shadnaz; Vespa, Paul; Bergsneider, Marvin; Hu, Xiao

    2011-01-01

    Lactate/pyruvate ratio (LPR) from microdialysis is a well-established marker of cerebral metabolic crisis. For brain injury patients, abnormally high LPR could indicate cerebral ischemia or failure of O 2 uptake. However, there is a debate on the primary factor responsible for LPR increase. Exploiting the potential of using the morphology of a high temporal resolution signal such as intracranial pulse (ICP) to characterize cerebrovascular changes, a data analysis experiment is taken to test whether consistent changes in ICP pulse morphological metrics accompany the LPR increase. We studied 3517 h of LPR and continuous ICP data from 19 severe traumatic brain injury patients. Our morphological clustering and analysis of intracranial pressure (MOCAIP) algorithm was applied to ICP pulses, which were matched in time to the LPR measurements, and 128 pulse morphological metrics were extracted. We automatically identified the episodes of LPR increases using a moving time window of 10–20 h. We then studied the trending patterns of each of the 128 ICP MOCAIP metrics within these identified periods and determined them to be one of the following three types: increasing, decreasing or no trend. A binomial test was employed to investigate whether any MOCAIP metrics show a consistent trend among all episodes of LPR increase per patient. Regardless of the selected values for different parameters of the proposed method, for the majority of the subjects in the study (78%), none of the ICP metrics show any consistent trend during the episodes of LPR increase. Even for the few subjects who have at least one ICP metric with a consistent trend during the LPR increase episodes, the number of such metrics is small and varies from subject to subject. Given the fact that ICP pulse morphology is influenced by the cerebral vasculature, our results suggest that a dominant cerebral vascular cause may be behind the changes in LPR when LPR trends correlate with ICP pulse morphological changes

  7. Distribution of phosphorylated metabolites and magnesium in the red cells of a patient with hyperactive pyruvate kinase

    International Nuclear Information System (INIS)

    Ouwerkerk, R.; van Echteld, C.J.; Staal, G.E.; Rijksen, G.

    1988-01-01

    The intracellular distribution of adenosine 5'-triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) was studied in the red cells of a patient with a high-ATP syndrome by using 31P nuclear magnetic resonance. In this patient, red cell ATP was increased 2.5-fold, whereas 2,3-DPG was decreased fourfold due to the presence of a hyperactive pyruvate kinase. In oxygenated red cells, these abnormal concentrations were reflected to the same extent in all complexes in which ATP and 2,3-DPG take part. The diminished amount of 2,3-DPG bound to hemoglobin was almost completely replaced by ATP-hemoglobin complexes. Therefore, free hemoglobin was only slightly increased. In deoxygenated cells, the relative distribution of ATP and 2,3-DPG complexes was significantly disturbed. The main difference was a shift in the ratio of magnesium ATP (MgATP) over the ATP-hemoglobin complex; 74% of total ATP was complexed to hemoglobin (45% in normal cells), whereas the concentration of MgATP was only slightly increased with respect to normal. The shortage in 2,3-DPG bound to hemoglobin could partially be replenished by an increase in hemoglobin (Mg) ATP complexes. Therefore, the amount of uncomplexed hemoglobin raised from 15% in normal cells to 38% in the patient's cells. As a result, the oxygen-dissociation curve was only moderately shifted to the left. It is concluded that the regulatory role of 2,3-DPG in oxygen transport is taken over in part by (Mg) ATP in this patient. In both aerobic and anaerobic cells, the increase in magnesium bound to ATP, either free or bound to hemoglobin, exceeds the decrease in 2,3-DPG Mg complex. In spite of this, the amount of intracellular free Mg++ was normal or slightly lowered. This suggests the presence of a compensatory mechanism by which the amount of total cellular magnesium could be increased

  8. Special report: Mt. St. Helens

    Science.gov (United States)

    Mt. St Helens Volcano, Cascade Range, Southern Washington, USA (46.20°N, 122.18°W.) All times are local (GMT - 7 h through October 24, GMT - 8 h thereafter. Lava extrusion that probably began October 30 added a new lobe to the composite dome in the crater of Mt. St. Helens. After lava extrusion ended September 10 (see September 22 Eos), rates of deformation in the crater remained low for several weeks, as they had after earlier extrusion episodes. Sulfur dioxide emission ranged from 70 to 190 tons per day between October 9 and 24, but showed no particular trends. Inflation of the dome has caused small thrust faults to form in the surrounding crater floor. In early October the most active thrust, south of the dome, was moving at about 1.5 cm/d, and stations on the north crater rampart showed outward movement of about 0.5 cm/d. By October 24 these rates had increased to 14.5 and 3.5-4 cm/d, respectively, and leveling profiles perpendicular to the dome showed that crater floor tilt rates had reached 400-500 μrad/d, prompting the U.S. Geological Survey (USGS) to issue an advisory prediction of renewed lava extrusion within the next two weeks.

  9. Effets de la substitution par l'arachide fourragère (Arachis glabrata de l'herbe à éléphant (Pennisetum purpurum sur le nombre d'ovulations et les mortalités prénatales chez le cobaye (Cavia porcellus L. adulte

    Directory of Open Access Journals (Sweden)

    Kenfack, A.

    2006-01-01

    Full Text Available Effects of Arachis glabrata Substitution to Pennisetum purpurum on the Ovulations'Number and the Prenatal Mortalities in Adult Guinea-pig Cavia porcellus L. In order to study the effects of Pennisetum purpurum substitution by Arachis glabrata on the ovulations' number and the prenatal mortalities in guinea-pigs, 36 animals including 30 females and 6 males were divided into 3 identical groups. To each group were randomly allotted one of the three diets characterised by its substitution level. The number of ovulation (2.20 ± 0.30, identical between the two rations with less legumes forage has been higher compared to the diet containing the greatest quantity of legume (2.00 ± 0.40. Only the group of guinea-pigs fed with a ration including the second highest level of forage legume recorded one prenatal mortality, which represented 4.20% of formed zygotes.

  10. Some fossil Clypeastrids (Echinoidea) from Brimstone Hill (St. Kitts) and Sugar Loaf (St. Eustatius), Lesser Antilles

    NARCIS (Netherlands)

    Engel, H.

    1961-01-01

    In March 1958 Dr. J. H. WESTERMANN and Mr. H. KIEL collected some fossil Echinids on the islands of St. Kitts and St. Eustatius. The fossils of St. Kitts were found in a yellow limestone (sample nr. 42), situated on the west flank of Brimstone Hill, belonging to a series of peculiar-looking upturned

  11. Altered cytotoxicity of ROS-inducing compounds by sodium pyruvate in cell culture medium depends on the location of ROS generation.

    Science.gov (United States)

    Kelts, Jessica L; Cali, James J; Duellman, Sarah J; Shultz, John

    2015-01-01

    Induction of oxidative stress by drugs and other xenobiotics is an important mechanism of cytotoxicity. However, in vitro studies on the relationship between oxidative stress and cytotoxicity in cultured cells is frequently complicated by the fact that cell culture medium components affect reactive oxygen species (ROS) exposures in ways that vary with the mode of ROS production. The objectives of this study were to first determine the mode of ROS induction by certain model compounds when they are applied to cultured cells, and then to determine how ROS induction and cytotoxicity were affected by the ROS-quenching medium component pyruvate. Three compounds, eseroline, benserazide, and pyrogallol induced H2O2 in cell culture media independent of cells. However, another compound, menadione, induced H2O2 in a manner largely dependent on the MDA-MB-231 breast cancer cells used in this study, which is consistent with its known mechanism of inducing ROS through intracellular redox cycling. 1 mM pyruvate, as well as catalase, reduced the H2O2 in culture wells with each ROS inducer tested but it only reduced the cytotoxicity of cell-independent inducers. It reduced the cytotoxicity of benserazide and pyrogallol >10-fold and of eseroline about 2.5-fold, but had no effect on menadione cytotoxicity. From this data, it was concluded that depending on the mechanism of ROS induction, whether intra- or extracellular, a ROS-quenching medium component such as pyruvate will differentially affect the net ROS-induction and cytotoxicity of a test compound.

  12. 21st Century Security Manager

    Directory of Open Access Journals (Sweden)

    Stelian ARION

    2010-11-01

    Full Text Available We live in world of uncertainty that generates major paradigms changing that affect security risk management. Modern organization’s security risks management can’t be done without a profound knowlegde and daily practice for security governance, security risk management and resilience. 21st Century security manager need to deal with several areas of konwledge in order to succesfully manage security risks. The document presents the advantages, disadvantages and challenges for security managers thah have government backgroud, or IT security backgroud, or are promoted from organization’s inside leaders. There are six different areas of knowledge that successful security programs of the future must incorporate, either in the knowledge base of their leaders or in the collective knowledge of the leading staff. They are government elements, security organization, emerging issue awareness, IT security, business elements and executive leadership.

  13. Countering 21st Century Threats

    DEFF Research Database (Denmark)

    Scharling Pedersen, Peter; Pillai, Chad M.; Hun, Lee Jae

    2015-01-01

    The United States and its Allies confront an increasingly volatile world where threats range from traditional state-on-state challenges to non-state transnational networks. To successfully combat these 21st Century problems, in an era of resource and geo-political power constraints, the U...... to be addressed in order to successfully conduct IW. As result of researching the issues associated with developing a JIIM approach to IW, the paper makes the following recommendations: • Establishing universally accepted concepts and doctrines for IW, UW, Foreign Internal Defense (FID), Counter Insurgency (COIN......), Counter-Terrorism (CT), and Security and Stability Operations (SSO). • Establishing a construct that allows a strategic Whole-of-Government capacity for operations coordinated by joint interagency task forces. • Continue to developing the Global SOF network. • Increased intelligence sharing in areas...

  14. 21st International Meshing Roundtable

    CERN Document Server

    Weill, Jean-Christophe

    2013-01-01

    This volume contains the articles presented at the 21st International Meshing Roundtable (IMR) organized, in part, by Sandia National Laboratories and was held on October 7–10, 2012 in San Jose, CA, USA. The first IMR was held in 1992, and the conference series has been held annually since. Each year the IMR brings together researchers, developers, and application experts in a variety of disciplines, from all over the world, to present and discuss ideas on mesh generation and related topics. The technical papers in this volume present theoretical and novel ideas and algorithms with practical potential, as well as technical applications in science and engineering, geometric modeling, computer graphics, and visualization.

  15. Pyruvate kinase deficiency

    Science.gov (United States)

    ... anemia may need blood transfusions. Removing the spleen ( splenectomy ) may help reduce the destruction of red blood ... donor blood or plasma. Someone who had a splenectomy should receive the pneumococcal vaccine at recommended intervals. ...

  16. Molecular association of glucose-6-phosphate isomerase and pyruvate kinase M2 with glyceraldehyde-3-phosphate dehydrogenase in cancer cells.

    Science.gov (United States)

    Das, Mahua R; Bag, Arup K; Saha, Shekhar; Ghosh, Alok; Dey, Sumit K; Das, Provas; Mandal, Chitra; Ray, Subhankar; Chakrabarti, Saikat; Ray, Manju; Jana, Siddhartha S

    2016-02-24

    For a long time cancer cells are known for increased uptake of glucose and its metabolization through glycolysis. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a key regulatory enzyme of this pathway and can produce ATP through oxidative level of phosphorylation. Previously, we reported that GAPDH purified from a variety of malignant tissues, but not from normal tissues, was strongly inactivated by a normal metabolite, methylglyoxal (MG). Molecular mechanism behind MG mediated GAPDH inhibition in cancer cells is not well understood. GAPDH was purified from Ehrlich ascites carcinoma (EAC) cells based on its enzymatic activity. GAPDH associated proteins in EAC cells and 3-methylcholanthrene (3MC) induced mouse tumor tissue were detected by mass spectrometry analysis and immunoprecipitation (IP) experiment, respectively. Interacting domains of GAPDH and its associated proteins were assessed by in silico molecular docking analysis. Mechanism of MG mediated GAPDH inactivation in cancer cells was evaluated by measuring enzyme activity, Circular dichroism (CD) spectroscopy, IP and mass spectrometry analyses. Here, we report that GAPDH is associated with glucose-6-phosphate isomerase (GPI) and pyruvate kinase M2 (PKM2) in Ehrlich ascites carcinoma (EAC) cells and also in 3-methylcholanthrene (3MC) induced mouse tumor tissue. Molecular docking analyses suggest C-terminal domain preference for the interaction between GAPDH and GPI. However, both C and N termini of PKM2 might be interacting with the C terminal domain of GAPDH. Expression of both PKM2 and GPI is increased in 3MC induced tumor compared with the normal tissue. In presence of 1 mM MG, association of GAPDH with PKM2 or GPI is not perturbed, but the enzymatic activity of GAPDH is reduced to 26.8 ± 5 % in 3MC induced tumor and 57.8 ± 2.3 % in EAC cells. Treatment of MG to purified GAPDH complex leads to glycation at R399 residue of PKM2 only, and changes the secondary structure of the protein complex. PKM2

  17. L-carnitine and pyruvate are prosurvival factors during the storage of stallion spermatozoa at room temperature.

    Science.gov (United States)

    Gibb, Zamira; Lambourne, Sarah R; Quadrelli, Julianne; Smith, Nathan D; Aitken, Robert J

    2015-10-01

    The spermatozoa of many stallions do not tolerate being cooled, restricting the commercial viability of these animals and necessitating the development of a chemically defined room temperature (RT) storage medium. This study examined the impact of two major modulators of oxidative phosphorylation, pyruvate (Pyr) and L-carnitine (L-C), on the storage of stallion spermatozoa at RT. Optimal concentrations of Pyr (10 mM) and L-C (50 mM) were first identified and these concentrations were then used to investigate the effects of these compounds on sperm functionality and oxidative stress at RT. Mitochondrial and cytosolic reactive oxygen species, along with lipid peroxidation, were all significantly suppressed by the addition of L-C (48 h MitoSOX Red negative: 46.2% vs. 26.1%; 48 and 72 h dihydroethidium negative: 61.6% vs. 43.1% and 64.4% vs. 46.9%, respectively; 48 and 72 h 4-hydroxynonenal negative: 37.1% vs. 23.8% and 41.6% vs. 25.7%, respectively), while the Pyr + L-C combination resulted in significantly higher motility compared to the control at 72 h (total motility: 64.2% vs. 39.4%; progressive motility: 34.2% vs. 15.2%). In addition, supplementation with L-C significantly reduced oxidative DNA damage at 72 h (9.0% vs. 15.6%). To investigate the effects of L-C as an osmolyte, comparisons were made between media that were osmotically balanced with NaCl, choline chloride, or L-C. This analysis demonstrated that spermatozoa stored in the L-C balanced medium had significantly higher total motility (55.0% vs. 39.0%), rapid motility (44.0% vs. 25.7%), and ATP levels (70.9 vs. 12.8 ng/ml) following storage compared with the NaCl treatment, while choline chloride did not significantly improve these parameters compared to the control. Finally, mass spectrometry was used to demonstrate that a combination of Pyr and L-C produced significantly higher acetyl-L-carnitine production than any other treatment (6.7 pg/10(6) spermatozoa vs. control at 4.0 pg/10(6) spermatozoa

  18. Molecular association of glucose-6-phosphate isomerase and pyruvate kinase M2 with glyceraldehyde-3-phosphate dehydrogenase in cancer cells

    International Nuclear Information System (INIS)

    Das, Mahua R.; Bag, Arup K.; Saha, Shekhar; Ghosh, Alok; Dey, Sumit K.; Das, Provas; Mandal, Chitra; Ray, Subhankar; Chakrabarti, Saikat; Ray, Manju; Jana, Siddhartha S.

    2016-01-01

    For a long time cancer cells are known for increased uptake of glucose and its metabolization through glycolysis. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a key regulatory enzyme of this pathway and can produce ATP through oxidative level of phosphorylation. Previously, we reported that GAPDH purified from a variety of malignant tissues, but not from normal tissues, was strongly inactivated by a normal metabolite, methylglyoxal (MG). Molecular mechanism behind MG mediated GAPDH inhibition in cancer cells is not well understood. GAPDH was purified from Ehrlich ascites carcinoma (EAC) cells based on its enzymatic activity. GAPDH associated proteins in EAC cells and 3-methylcholanthrene (3MC) induced mouse tumor tissue were detected by mass spectrometry analysis and immunoprecipitation (IP) experiment, respectively. Interacting domains of GAPDH and its associated proteins were assessed by in silico molecular docking analysis. Mechanism of MG mediated GAPDH inactivation in cancer cells was evaluated by measuring enzyme activity, Circular dichroism (CD) spectroscopy, IP and mass spectrometry analyses. Here, we report that GAPDH is associated with glucose-6-phosphate isomerase (GPI) and pyruvate kinase M2 (PKM2) in Ehrlich ascites carcinoma (EAC) cells and also in 3-methylcholanthrene (3MC) induced mouse tumor tissue. Molecular docking analyses suggest C-terminal domain preference for the interaction between GAPDH and GPI. However, both C and N termini of PKM2 might be interacting with the C terminal domain of GAPDH. Expression of both PKM2 and GPI is increased in 3MC induced tumor compared with the normal tissue. In presence of 1 mM MG, association of GAPDH with PKM2 or GPI is not perturbed, but the enzymatic activity of GAPDH is reduced to 26.8 ± 5 % in 3MC induced tumor and 57.8 ± 2.3 % in EAC cells. Treatment of MG to purified GAPDH complex leads to glycation at R399 residue of PKM2 only, and changes the secondary structure of the protein complex. PKM2

  19. Firmaets Største Bedrift

    DEFF Research Database (Denmark)

    Hansen, Peer Henrik

    fortæller, hvordan de tidligere modstandsfolk Arne Sejr og Niels Frommelt få år efter befrielsen etablerede deres såkaldte Firma for med støtte fra ledende danske politikere, Forsvarets Efterretningstjeneste og CIA at organisere en hemmelig krig mod Sovjetunionens danske støtter. Meget tyder på, at både...

  20. 78 FR 7663 - SLR; 2013 International Rolex Regatta; St. Thomas Harbor; St. Thomas, U.S. Virgin Islands

    Science.gov (United States)

    2013-02-04

    ... 1625-AA08 SLR; 2013 International Rolex Regatta; St. Thomas Harbor; St. Thomas, U.S. Virgin Islands... special local regulations on the waters of St. Thomas Harbor in St. Thomas, U. S. Virgin Islands during... through March 24, 2013, the St. Thomas Yacht Club is sponsoring the 2013 Rolex Regatta, a series of sail...

  1. 78 FR 22778 - Safety Zone; Corp. Event Finale UHC, St. Thomas Harbor; St. Thomas, U.S.V.I.

    Science.gov (United States)

    2013-04-17

    ...-AA00 Safety Zone; Corp. Event Finale UHC, St. Thomas Harbor; St. Thomas, U.S.V.I. AGENCY: Coast Guard... waters of St. Thomas Harbor in St. Thomas, U.S. Virgin Islands during the Corp. Event Finale UHC, a... barge being positioned near the St. Thomas Harbor channel from which fireworks will be lit. The safety...

  2. 78 FR 23489 - Safety Zone; V.I. Carnival Finale, St. Thomas Harbor; St. Thomas, U.S.V.I.

    Science.gov (United States)

    2013-04-19

    ...-AA00 Safety Zone; V.I. Carnival Finale, St. Thomas Harbor; St. Thomas, U.S.V.I. AGENCY: Coast Guard... waters of St. Thomas Harbor in St. Thomas, U.S. Virgin Islands during the V.I. Carnival Finale, a... being positioned near the St. Thomas Harbor channel from which fireworks will be lit. The safety zone is...

  3. 78 FR 16208 - Safety Zone; V. I. Carnival Finale; St. Thomas Harbor; St. Thomas, U.S. Virgin Islands

    Science.gov (United States)

    2013-03-14

    ... 1625-AA00 Safety Zone; V. I. Carnival Finale; St. Thomas Harbor; St. Thomas, U.S. Virgin Islands AGENCY... establish a safety zone on the waters of St. Thomas Harbor in St. Thomas, U. S. Virgin Islands during the V..., 2013, and will entail a barge being positioned near the St. Thomas Harbor channel from which fireworks...

  4. 78 FR 16211 - Safety Zone, Corp. Event Finale UHC, St. Thomas Harbor; St. Thomas, U.S. Virgin Islands

    Science.gov (United States)

    2013-03-14

    ... 1625-AA00 Safety Zone, Corp. Event Finale UHC, St. Thomas Harbor; St. Thomas, U.S. Virgin Islands... establish a temporary safety zone on the waters of St. Thomas Harbor in St. Thomas, U.S. Virgin Islands... near the St. Thomas Harbor channel from which fireworks will be lit. DATES: Comments and related...

  5. Galleria mellonella infection model demonstrates high lethality of ST69 and ST127 uropathogenic E. coli.

    Directory of Open Access Journals (Sweden)

    Majed F Alghoribi

    Full Text Available Galleria mellonella larvae are an alternative in vivo model for investigating bacterial pathogenicity. Here, we examined the pathogenicity of 71 isolates from five leading uropathogenic E. coli (UPEC lineages using G. mellonella larvae. Larvae were challenged with a range of inoculum doses to determine the 50% lethal dose (LD50 and for analysis of survival outcome using Kaplan-Meier plots. Virulence was correlated with carriage of a panel of 29 virulence factors (VF. Larvae inoculated with ST69 and ST127 isolates (10(4 colony-forming units/larvae showed significantly higher mortality rates than those infected with ST73, ST95 and ST131 isolates, killing 50% of the larvae within 24 hours. Interestingly, ST131 isolates were the least virulent. We observed that ST127 isolates are significantly associated with a higher VF-score than isolates of all other STs tested (P≤0.0001, including ST69 (P<0.02, but one ST127 isolate (strain EC18 was avirulent. Comparative genomic analyses with virulent ST127 strains revealed an IS1 mediated deletion in the O-antigen cluster in strain EC18, which is likely to explain the lack of virulence in the larvae infection model. Virulence in the larvae was not correlated with serotype or phylogenetic group. This study illustrates that G. mellonella are an excellent tool for investigation of the virulence of UPEC strains. The findings also support our suggestion that the incidence of ST127 strains should be monitored, as these isolates have not yet been widely reported, but they clearly have a pathogenic potential greater than that of more widely recognised clones, including ST73, ST95 or ST131.

  6. Assessing the survival of MRC5 and a549 cell lines upon exposure to pyruvic Acid, sodium citrate and sodium bicarbonate - biomed 2013.

    Science.gov (United States)

    Farah, Ibrahim O; Lewis, Veshell L; Ayensu, Wellington K; Cameron, Joseph A

    2013-01-01

    Lung cancer is among the most prevalent and deadly cancers in United States. In general, cancer cells are known to exhibit higher rates of glycolysis in comparison to normal cells. In attempting to exploit this unique cancer-dependent ATP generation phenomenon, it was our hypothesis that upon exposure to organic inhibitors of glycolysis, cancer cells would not survive normally and that their growth and viability would be vastly decreased; essential glycolytic ATP production will be exhausted to the point of collapsing energy utilization. Furthermore, we hypothesize that no negative effect would be seen with exposures to organic inhibitors for normal lung cells. The human lung fibroblast MRC-5 and the human A549 alveolar epithelial cell lines were used as in vitro models of normal lung and lung cancers respectively. Using standard methods, both cell lines were maintained and exposed to pyruvic acid, sodium citrate and sodium bicarbonate reagents at concentration levels ranging from 31.3-2,000 µg/ml in 96 well plates in quadruplets and experiments repeated at least three times using MTT, and cell counting (T4 Cellometer) assays as well as phase-contrast photo-imaging for parallel morphological displays of any changes in the course of their vitality and metabolic activities. Our results indicate that exposure of both cell lines to these organics resulted in concentration dependent cell destruction/cell survival depending on the cell line exposed. Pyruvic acid, sodium citrate and sodium bicarbonate showed statistically significant (pcancer biotherapeutics.

  7. Determination of pyruvate and lactate as potential biomarkers of embryo viability in assisted reproduction by capillary electrophoresis with contactless conductivity detection.

    Science.gov (United States)

    Mádr, Aleš; Celá, Andrea; Klejdus, Bořivoj; Pelcová, Marta; Crha, Igor; Žáková, Jana; Glatz, Zdeněk

    2015-06-01

    Human-assisted reproduction is increasing in importance due to the constantly rising number of couples suffering from infertility issue. A key step in in vitro fertilization is the proper assessment of embryo viability in order to select the embryo with the highest likelihood of resulting in a pregnancy. This study proposes a method based on CE with contactless conductivity detection for the determination of pyruvate and lactate in spent culture media used in human-assisted reproduction. A fused-silica capillary of 64.0 cm total length and 50 μm inner diameter was used. The inner capillary wall was modified by the coating of successive layers of the ionic polymers polybrene and dextran sulfate to reverse EOF. The BGE was composed of 10 mM MES/lithium hydroxide, pH 6.50. The sample was injected by pressure 50 mbar for 18 s, separation voltage was set to -24 kV, and capillary temperature to 15°C. The presented method requires only 2 μL of the culture medium, with LODs for pyruvate and lactate of 0.03 and 0.02 μM, respectively. The results demonstrated the method's suitability for the analysis of spent culture media to support embryo viability assessment by light microscopy, providing information about key metabolites of the energy metabolism of a developing embryo. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Activation of Pyruvate Dehydrogenase by Sodium Dichloroacetate Shifts Metabolic Consumption from Amino Acids to Glucose in IPEC-J2 Cells and Intestinal Bacteria in Pigs.

    Science.gov (United States)

    An, Rui; Tang, Zhiru; Li, Yunxia; Li, Tiejun; Xu, Qingqing; Zhen, Jifu; Huang, Feiru; Yang, Jing; Chen, Cheng; Wu, Zhaoliang; Li, Mao; Sun, Jiajing; Zhang, Xiangxin; Chen, Jinchao; Wu, Liuting; Zhao, Shengjun; Qingyan, Jiang; Zhu, Weiyun; Yin, Yulong; Sun, Zhihong

    2018-04-18

    The extensive metabolism of amino acids (AA) as fuel is an important reason for the low use efficiency of protein in pigs. In this study, we investigated whether regulation of the pyruvate dehydrogenase kinase (PDK)/pyruvate dehydrogenase alpha 1 (PDHA1) pathway affected AA consumption by porcine intestinal epithelial (IPEC-J2) cells and intestinal bacteria in pigs. The effects of knockdown of PDHA1 and PDK1 with small interfering RNA (siRNA) on nutrient consumption by IPEC-J2 cells were evaluated. IPEC-J2 cells were then cultured with sodium dichloroacetate (DCA) to quantify AA and glucose consumption and nutrient oxidative metabolism. The results showed that knockdown of PDHA1 using siRNA decreased glucose consumption but increased total AA (TAA) and glutamate (Glu) consumption by IPEC-J2 cells ( P < 0.05). Opposite effects were observed using siRNA targeting PDK1 ( P < 0.05). Additionally, culturing IPEC-J2 cells in the presence of 5 mM DCA markedly increased the phosphorylation of PDHA1 and PDH phosphatase 1, but inhibited PDK1 phosphorylation ( P < 0.05). DCA treatment also reduced TAA and Glu consumption and increased glucose depletion ( P < 0.05). These results indicated that PDH was the regulatory target for shifting from AA metabolism to glucose metabolism and that culturing cells with DCA decreased the consumption of AAs by increasing the depletion of glucose through PDH activation.

  9. The regulation of glucose and pyruvate formation from glutamine and citric-acid-cycle intermediates in the kidney cortex of rats, dogs, rabbits and guinea pigs.

    Science.gov (United States)

    Watford, M; Vinay, P; Lemieux, G; Gougoux, A

    1980-01-01

    The suppression by 3-mercaptopicolinate of gluconeogenesis from glutamine or 2-oxoglutarate in rat or dog kidney tubules did not affect the amount of these substrates undergoing complete oxidation. Furthermore, 3-mercaptopicolinate caused an accumulation of lactate in dog tubules. 3-Mercaptopicolinate abolished both gluconeogenesis and substrate oxidation in tubules from rabbit and guinea-pig kidney. These results imply the presence of an alternative pathway to phosphoenolpyruvate carboxykinase/pyruvate kinase for the production of pyruvate from citric-acid-cycle intermediates in the kidney cortex of rats and dogs but not in that of rabbits or guinea pigs. Oxaloacetate decarboxylase (present in the kidney cortex of all four species) or 'malic' enzyme (present in rat and dog but absent in rabbit and guinea-pig kidney cortex) could function in this role. Our observations indicate that 'malic' enzyme is probably implicated in this phenomenon. The lactate production observed in dog tubules in the presence of 3-mercaptopicolinate can be suppressed when aspartate formation is inhibited by 2-amino-4-methoxy-trans-but-3-enoic acid. This suggests that the provision of cytosolic NADH from citric-acid-cycle intermediates is facilitated by accumulation of aspartate acting as a 'sink' for cytosolic oxaloacetate. PMID:7470031

  10. Insulin-induced inhibition of gluconeogenesis genes, including glutamic pyruvic transaminase 2, is associated with reduced histone acetylation in a human liver cell line.

    Science.gov (United States)

    Honma, Kazue; Kamikubo, Michiko; Mochizuki, Kazuki; Goda, Toshinao

    2017-06-01

    Hepatic glutamic pyruvic transaminase (GPT; also known as alanine aminotransferase) is a gluconeogenesis enzyme that catalyzes conversions between alanine and pyruvic acid. It is also used as a blood biomarker for hepatic damage. In this study, we investigated whether insulin regulates GPT expression, as it does for other gluconeogenesis genes, and if this involves the epigenetic modification of histone acetylation. Human liver-derived HepG2 cells were cultured with 0.5-100nM insulin for 8h, and the mRNA expression of GPT, glutamic-oxaloacetic transaminase (GOT), γ-glutamyltransferase (GGT), PCK1, G6PC and FBP1 was measured. We also investigated the extent of histone acetylation around these genes. Insulin suppressed the mRNA expression of gluconeogenesis genes (GPT2, GOT1, GOT2, GGT1, GGT2, G6PC, and PCK1) in HepG2 cells in a dose-dependent manner. mRNA levels of GPT2, but not GPT1, were decreased by insulin. Histone acetylation was also reduced around GPT2, G6PC, and PCK1 in response to insulin. The expression of GPT2 and other gluconeogenesis genes such as G6PC and PCK1 was suppressed by insulin, in association with decreases in histone H3 and H4 acetylation surrounding these genes. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Coordinate cis-[Cr(C2O4(pm(OH22]+ Cation as Molecular Biosensor of Pyruvate’s Protective Activity Against Hydrogen Peroxide Mediated Cytotoxity

    Directory of Open Access Journals (Sweden)

    Lech Chmurzyński

    2008-08-01

    Full Text Available In this paper instrumental methods of carbon dioxide (CO2 detection in biological material were compared. Using cis-[Cr(C2O4(pm(OH22]+ cation as a specific molecular biosensor and the stopped-flow technique the concentrations of CO2 released from the cell culture medium as one of final products of pyruvate decomposition caused by hydrogen peroxide were determined. To prove the usefulness of our method of CO2 assessment in the case of biological samples we investigated protective properties of exogenous pyruvate in cultured osteosarcoma 143B cells exposed to 1 mM hydrogen peroxide (H2O2 added directly to culture medium. Pyruvic acid is well known scavenger of H2O2 and, moreover, a molecule which is recognized as one of the major mediator of oxidative stress detected in many diseases and pathological situations like ischemiareperfusion states. The pyruvate's antioxidant activity is described as its rapid reaction with H2O2,which causes nonenzymatic decarboxylation of pyruvate and releases of CO2, water and acetate as final products. In this work for the first time we have correlated the concentration of CO2 dissolved in culture medium with pyruvate's oxidant-scavenging abilities. Moreover, the kinetics of the reaction between aqueous solution of CO2 and coordinate ion, cis-[Cr(C2O4(pm(OH22]+ was analysed. The results obtained enabled determination of the number of steps of the reaction studied. Based on the kinetic equations, rate constants were determined for each step.

  12. Ableitung des Selenbedarfs wachsender Meerschweinchen (Cavia porcellus)

    OpenAIRE

    Jensen, Christine

    2008-01-01

    Der Selenbedarf des Meerschweinchens wurde in der Vergangenheit von dem der Ratte abgeleitet und wurde für wachsende und ausgewachsene Meerschweinchen mit 0,15 mg/kg Futtermittel angegeben (NRC 1995). Da beide Tierarten auf Grund zahlreicher Unterschiede im antioxidativen Stoffwechsel nur begrenzt miteinander vergleichbar sind, wurde in dieser Arbeit der Selenbedarf für wachsende Meerschweinchen abgeleitet. In einem Fütterungsversuch wurden sechs Versuchsgruppen à 7 Tiere gebildet, di...

  13. ST peak during percutaneous coronary intervention serves as an early prognostic predictor in patients with ST-segment elevation myocardial

    DEFF Research Database (Denmark)

    Lønborg, Jacob; Kelbæk, Henning; Engstrøm, Thomas

    2014-01-01

    AIMS: To evaluate the clinical importance of the ST peak phenomenon during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). METHODS AND RESULTS: Continuous ST monitoring was performed in 942 STEMI patients from arrival until 90...... minutes after revascularisation. ST peak was defined as ≥1 mm increase in the ST-segment during PCI compared with the ST elevation before intervention. ST peak was observed in 26.9% of patients. During median follow-up of 4.1 years, 20.7% of patients experienced a major adverse cardiac event (MACE). ST...

  14. Urbanization in 21st century.

    Science.gov (United States)

    Altarejos, R G

    1990-01-01

    Due to a combination of rapid population growth and high levels of rural-urban migration, overcrowding will be common in many cities around the world in the 21st century. Currently at 5.3 billion, the global population is expected to increase to 6 billion by the year 2000, and to 9 billion by 2025. Experts predict that urban centers will bear the brunt of the population growth. Rural areas have seen declines in the standard of living, partly due to natural disasters, civil war, and economic policies favoring urban centers. In search of jobs, better access to education, and health services, rural populations will flock to cities. But the rapid growth of cities will inevitably lead to the creation of slums, which will hamper urban development. Urban demographers predict that by the end of the century, 1/2 of the world's population will be urban, and 1/5 of these people will be concentrated in "mega cities," populations of 4 million or more. International migration will play a significant role, as people cross borders in search of opportunity. But contrary to the traditional model of urban growth, much of it will take place in developing countries. According to a 1985 study, developed nations had an urbanization level of 71%, compared to 31% in developing countries. However, experts calculate that by 2025, these levels will practically even out, with an urbanization level of 74% for developing countries and 77% for developed countries. By 2025, 25 cities will have populations of over 9 million, including Mexico City (25.8), Sao Paulo (24.0), Tokyo (20.2), Calcutta (16.5), Greater Bombay (16.0), and New York (15.8).

  15. Integrable quantum Stäckel systems

    International Nuclear Information System (INIS)

    Błaszak, Maciej; Domański, Ziemowit; Sergyeyev, Artur; Szablikowski, Błażej M.

    2013-01-01

    The Stäckel separability of a Hamiltonian system is well known to ensure existence of a complete set of Poisson commuting integrals of motion quadratic in the momenta. We consider a class of Stäckel separable systems where the entries of the Stäckel matrix are monomials in the separation variables. We show that the only systems in this class for which the integrals of motion arising from the Stäckel construction keep commuting after quantization are, up to natural equivalence transformations, the so-called Benenti systems. Moreover, it turns out that the latter are the only quantum separable systems in the class under study.

  16. Specification For ST-5 Li Ion Battery

    Science.gov (United States)

    Castell, Karen D.; Day, John H. (Technical Monitor)

    2000-01-01

    This Specification defines the general requirements for rechargeable Space Flight batteries intended for use in the ST-5 program. The battery chemistry chosen for this mission is lithium ion (Li-Ion).

  17. Location - Managed Facility - St. Paul District (MVP)

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — St. Paul District - US Army Corps of Engineers Managed Facility locations. District headquarters, Natural Resource, Recreation, Lock and Dam, and Regulatory offices...

  18. Control Strategy Tool (CoST)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EPA Control Strategy Tool (CoST) is a software tool for projecting potential future control scenarios, their effects on emissions and estimated costs. This tool...

  19. 2014 Lidar DEM: St. Charles Parish (LA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Under this task order, Precision Aerial Reconnaissance, LLC was contracted to provide acquisition and processing of airborne Lidar over St. Charles Parish,...

  20. Nursing research in the 21 st century

    Directory of Open Access Journals (Sweden)

    Roger Watson

    2013-01-01

    Conclusion: Nursing research has developed greatly over the past century and continues to develop in the 21 st century. Nursing research is relevant to the needs of patients and has had an impact on clinical practice.

  1. 2008 St. Johns County, FL Countywide Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne terrestrial LiDAR was collected for St. Johns County, FL. System Parameters/Flight Plan. The LiDAR system acquisition parameters were developed based on a...

  2. Meteor detection on ST (MST) radars

    International Nuclear Information System (INIS)

    Avery, S.K.

    1987-01-01

    The ability to detect radar echoes from backscatter due to turbulent irregularities of the radio refractive index in the clear atmosphere has lead to an increasing number of established mesosphere - stratosphere - troposphere (MST or ST) radars. Humidity and temperature variations are responsible for the echo in the troposphere and stratosphere and turbulence acting on electron density gradients provides the echo in the mesosphere. The MST radar and its smaller version, the ST radar, are pulsed Doppler radars operating in the VHF - UHF frequency range. These echoes can be used to determine upper atmosphere winds at little extra cost to the ST radar configuration. In addition, the meteor echoes can supplement mesospheric data from an MST radar. The detection techniques required on the ST radar for delineating meteor echo returns are described

  3. St. John's Wort (Hypericum Perforatum) and Pregnancy

    Science.gov (United States)

    ... amount of time it takes your body to eliminate half of the dose of the medication). It ... 2006. St. John’s wort (Hypericum perforatum) and breastfeeding: plasma and breast milk concentrations of hyperforin for 5 ...

  4. Fossil fuels in the 21st century.

    Science.gov (United States)

    Lincoln, Stephen F

    2005-12-01

    An overview of the importance of fossil fuels in supplying the energy requirements of the 21st century, their future supply, and the impact of their use on global climate is presented. Current and potential alternative energy sources are considered. It is concluded that even with substantial increases in energy derived from other sources, fossil fuels will remain a major energy source for much of the 21st century and the sequestration of CO2 will be an increasingly important requirement.

  5. St Sava and the cloud-chasers

    OpenAIRE

    Loma Aleksandar

    2013-01-01

    A gloss in the Nomocanon of St Sava condemns folk superstitions related to magically provoking hailstorms and eclipses. St Sava’s miracle with the king of Hungary as described in his Vitae seems to go back to the same complex of popular beliefs. Its acceptance by the hagiography was probably due to the influence of the figure of prince magician as common to the Serbian and the Russian oral epics.

  6. St Sava and the cloud-chasers

    Directory of Open Access Journals (Sweden)

    Loma Aleksandar

    2013-01-01

    Full Text Available A gloss in the Nomocanon of St Sava condemns folk superstitions related to magically provoking hailstorms and eclipses. St Sava’s miracle with the king of Hungary as described in his Vitae seems to go back to the same complex of popular beliefs. Its acceptance by the hagiography was probably due to the influence of the figure of prince magician as common to the Serbian and the Russian oral epics.

  7. Differentiating inflamed and normal lungs by the apparent reaction rate constants of lactate dehydrogenase probed by hyperpolarized (13)C labeled pyruvate.

    Science.gov (United States)

    Xu, He N; Kadlececk, Stephen; Shaghaghi, Hoora; Zhao, Huaqing; Profka, Harilla; Pourfathi, Mehrdad; Rizi, Rahim; Li, Lin Z

    2016-02-01

    Clinically translatable hyperpolarized (HP) (13)C-NMR can probe in vivo enzymatic reactions, e.g., lactate dehydrogenase (LDH)-catalyzed reaction by injecting HP (13)C-pyruvate into the subject, which is converted to (13)C labeled lactate by the enzyme. Parameters such as (13)C-lactate signals and lactate-to-pyruvate signal ratio are commonly used for analyzing the HP (13)C-NMR data. However, the biochemical/biological meaning of these parameters remains either unclear or dependent on experimental settings. It is preferable to quantify the reaction rate constants with a clearer physical meaning. Here we report the extraction of the kinetic parameters of the LDH reaction from HP (13)C-NMR data and investigate if they can be potential predictors of lung inflammation. Male Sprague-Dawley rats (12 controls, 14 treated) were used. One dose of bleomycin (2.5 U/kg) was administered intratracheally to the treatment group. The lungs were removed, perfused, and observed by the HP-NMR technique, where a HyperSense dynamic nuclear polarization system was used to generate the HP (13)C-pyruvate for injecting into the lungs. A 20 mm (1)H/(13)C dual-tuned coil in a 9.4-T Varian vertical bore NMR spectrometer was employed to acquire the (13)C spectral data every 1 s over a time period of 300 s using a non-selective, 15-degree radiofrequency pulse. The apparent rate constants of the LDH reaction and their ratio were quantified by applying ratiometric fitting analysis to the time series data of (13)C labeled pyruvate and lactate. The apparent forward rate constant kp =(3.67±3.31)×10(-4) s(-1), reverse rate constant kl =(4.95±2.90)×10(-2) s(-1), rate constant ratio kp /kl =(7.53±5.75)×10(-3) for the control lungs; kp =(11.71±4.35)×10(-4) s(-1), kl =(9.89±3.89)×10(-2) s(-1), and kp /kl =(12.39±4.18)×10(-3) for the inflamed lungs at the 7(th) day post treatment. Wilcoxon rank-sum test showed that the medians of these kinetic parameters of the 7-day cohort were significantly

  8. Increased lactate/pyruvate ratio with normal beta-hydroxybutyrate/acetoacetate ratio and lack of oxygen supply dependency in a patient with fatal septic shock.

    Science.gov (United States)

    Gallet, D; Goudable, J; Vedrinne, J M; Viale, J P; Annat, G

    1997-01-01

    We report a case of fatal septic shock, with hyperlactatemia and blood cultures positive for Streptococcus pneumoniae, in a 70-year-old patient. On two occasions (5 days, and 2 days before the patient's death), the relationship between oxygen delivery (DO2) and consumption (VO2) was examined in conjunction with two presumed markers of tissue oxygenation: the lactate/pyruvate ratio (L/P), and the beta-hydroxybutyrate acetoacetate ratio (beta OHB/AcAc). Increasing DO2 by about 30% ("oxygen flux test") failed to increase VO2. The beta OHB/AcAc ratio remained within normal limits, thus suggesting uncompromised tissue oxygenation at the hepatic level. The L/P ratio remained persistently above normal limits, thus suggesting actual organ or regional hypoxia. This case shows that during an overwhelming septic shock, the "oxygen flux test" can be negative, despite the presence of hyperlactatemia and of an increased L/P ratio suggestive of impaired tissue oxygenation.

  9. THE CATALYTIC DOMAIN OF THE DIHYDROLIPOYL TRANSACETYLASE COMPONENT OF THE PYRUVATE-DEHYDROGENASE COMPLEX FROM AZOTOBACTER-VINELANDII AND ESCHERICHIA-COLI - EXPRESSION, PURIFICATION, PROPERTIES AND PRELIMINARY-X-RAY ANALYSIS

    NARCIS (Netherlands)

    SCHULZE, E; WESTPHAL, AH; OBMOLOVA, G; MATTEVI, A; HOL, WGJ; DEKOK, A

    1991-01-01

    Partial sequences of the dihydrolipoyl transacetylase component (E2p) of the pyruvate dehydrogenase complex from Azotobacter vinelandii and Escherichia coli, containing the catalytic domain, were cloned in pUC plasmids and over-expressed in E. coli TG2. A high expression of a homogeneous protein was

  10. High-performance liquid chromatography-fluorescence assay of pyruvic acid to determine cysteine conjugate beta-lyase activity : application to S-1,2-dichlorovinyl-L-cysteine and S-2-benzothiazolyl-L-cysteine

    NARCIS (Netherlands)

    Stijntjes, G.J.; te Koppele, J.M.; Vermeulen, N P

    1992-01-01

    An HPLC-fluorescence assay has been developed for the determination of the activity of rat renal cytosolic cysteine conjugate beta-lyase. The method is based on isocratic HPLC separation and fluorescence detection of pyruvic acid, derivatized with o-phenylenediamine (OPD), and is shown to be rapid,

  11. St. James marine terminal facility description

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    The US Department of Energy (DOE) currently owns and operates a marine terminal on the west bank of the Mississippi River at St. James, Louisiana. The St. James facility was constructed by the Department to provide marine services associated with the fill and drawdown of the Strategic Petroleum Reserve (SPR) crude oil storage facilities located at Bayou Choctaw and Weeks Island, Louisiana. Although strategic to the mission of the SPR in the event of a national emergency, the St. James terminal is situated such that it has a high potential to also serve the commercial industry`s needs for crude oil terminalling and storage. The St. James terminal is located approximately 45 miles west of New Orleans and 30 miles southeast of Baton Rouge, and approximately 160 miles upstream from the mouth of the Mississippi River. Construction of the St. James terminal was initiated in 1978 and was completed in 1980. Since then, the terminal has received and transferred over 125 million barrels of crude oil to the SPR sites for storage. For crude oil distribution, the St. James terminal was connected to the neighboring LOCAP terminal by a 0.1 mile 36-inch pipeline in 1981 and to the Capline terminal by a 0.5 mile 30-inch pipeline in 1988. The terminal also has a 30-inch pipeline connection to the Koch oil terminal which was used for initial fill purposes; however, this pipeline has been disconnected and is currently inactive. A complete description of the St. James terminal facilities, operational capabilities, operational certifications, and future Government requirements are presented in Sections 2, 3, 4, and 5 respectively.

  12. Glycolytic Functions Are Conserved in the Genome of the Wine Yeast Hanseniaspora uvarum, and Pyruvate Kinase Limits Its Capacity for Alcoholic Fermentation.

    Science.gov (United States)

    Langenberg, Anne-Kathrin; Bink, Frauke J; Wolff, Lena; Walter, Stefan; von Wallbrunn, Christian; Grossmann, Manfred; Heinisch, Jürgen J; Schmitz, Hans-Peter

    2017-11-15

    Hanseniaspora uvarum (anamorph Kloeckera apiculata ) is a predominant yeast on wine grapes and other fruits and has a strong influence on wine quality, even when Saccharomyces cerevisiae starter cultures are employed. In this work, we sequenced and annotated approximately 93% of the H. uvarum genome. Southern and synteny analyses were employed to construct a map of the seven chromosomes present in a type strain. Comparative determinations of specific enzyme activities within the fermentative pathway in H. uvarum and S. cerevisiae indicated that the reduced capacity of the former yeast for ethanol production is caused primarily by an ∼10-fold-lower activity of the key glycolytic enzyme pyruvate kinase. The heterologous expression of the encoding gene, H. uvarum PYK1 ( HuPYK1 ), and two genes encoding the phosphofructokinase subunits, HuPFK1 and HuPFK2 , in the respective deletion mutants of S. cerevisiae confirmed their functional homology. IMPORTANCE Hanseniaspora uvarum is a predominant yeast species on grapes and other fruits. It contributes significantly to the production of desired as well as unfavorable aroma compounds and thus determines the quality of the final product, especially wine. Despite this obvious importance, knowledge on its genetics is scarce. As a basis for targeted metabolic modifications, here we provide the results of a genomic sequencing approach, including the annotation of 3,010 protein-encoding genes, e.g., those encoding the entire sugar fermentation pathway, key components of stress response signaling pathways, and enzymes catalyzing the production of aroma compounds. Comparative analyses suggest that the low fermentative capacity of H. uvarum compared to that of Saccharomyces cerevisiae can be attributed to low pyruvate kinase activity. The data reported here are expected to aid in establishing H. uvarum as a non- Saccharomyces yeast in starter cultures for wine and cider fermentations. Copyright © 2017 American Society for

  13. Pyruvate Carboxylase Is Up-Regulated in Breast Cancer and Essential to Support Growth and Invasion of MDA-MB-231 Cells.

    Directory of Open Access Journals (Sweden)

    Phatchariya Phannasil

    Full Text Available Pyruvate carboxylase (PC is an anaplerotic enzyme that catalyzes the carboxylation of pyruvate to oxaloacetate, which is crucial for replenishing tricarboxylic acid cycle intermediates when they are used for biosynthetic purposes. We examined the expression of PC by immunohistochemistry of paraffin-embedded breast tissue sections of 57 breast cancer patients with different stages of cancer progression. PC was expressed in the cancerous areas of breast tissue at higher levels than in the non-cancerous areas. We also found statistical association between the levels of PC expression and tumor size and tumor stage (P < 0.05. The involvement of PC with these two parameters was further studied in four breast cancer cell lines with different metastatic potentials; i.e., MCF-7, SKBR3 (low metastasis, MDA-MB-435 (moderate metastasis and MDA-MB-231 (high metastasis. The abundance of both PC mRNA and protein in MDA-MB-231 and MDA-MB-435 cells was 2-3-fold higher than that in MCF-7 and SKBR3 cells. siRNA-mediated knockdown of PC expression in MDA-MB-231 and MDA-MB-435 cells resulted in a 50% reduction of cell proliferation, migration and in vitro invasion ability, under both glutamine-dependent and glutamine-depleted conditions. Overexpression of PC in MCF-7 cells resulted in a 2-fold increase in their proliferation rate, migration and invasion abilities. Taken together the above results suggest that anaplerosis via PC is important for breast cancer cells to support their growth and motility.

  14. Identification of a Gene for Pyruvate-Insensitive Mitochondrial Alternative Oxidase Expressed in the Thermogenic Appendices in Arum maculatum1[W][OA

    Science.gov (United States)

    Ito, Kikukatsu; Ogata, Takafumi; Kakizaki, Yusuke; Elliott, Catherine; Albury, Mary S.; Moore, Anthony L.

    2011-01-01

    Heat production in thermogenic plants has been attributed to a large increase in the expression of the alternative oxidase (AOX). AOX acts as an alternative terminal oxidase in the mitochondrial respiratory chain, where it reduces molecular oxygen to water. In contrast to the mitochondrial terminal oxidase, cytochrome c oxidase, AOX is nonprotonmotive and thus allows the dramatic drop in free energy between ubiquinol and oxygen to be dissipated as heat. Using reverse transcription-polymerase chain reaction-based cloning, we reveal that, although at least seven cDNAs for AOX exist (AmAOX1a, -1b, -1c, -1d, -1e, -1f, and -1g) in Arum maculatum, the organ and developmental regulation for each is distinct. In particular, the expression of AmAOX1e transcripts appears to predominate in thermogenic appendices among the seven AmAOXs. Interestingly, the amino acid sequence of AmAOX1e indicates that the ENV element found in almost all other AOX sequences, including AmAOX1a, -1b, -1c, -1d, and -1f, is substituted by QNT. The existence of a QNT motif in AmAOX1e was confirmed by nano-liquid chromatography-tandem mass spectrometry analysis of mitochondrial proteins from thermogenic appendices. Further functional analyses with mitochondria prepared using a yeast heterologous expression system demonstrated that AmAOX1e is insensitive to stimulation by pyruvate. These data suggest that a QNT type of pyruvate-insensitive AOX, AmAOX1e, plays a crucial role in stage- and organ-specific heat production in the appendices of A. maculatum. PMID:21988877

  15. Impact of the Staphylococcus epidermidis LytSR two-component regulatory system on murein hydrolase activity, pyruvate utilization and global transcriptional profile

    Directory of Open Access Journals (Sweden)

    Yu Fangyou

    2010-11-01

    Full Text Available Abstract Background Staphylococcus epidermidis has emerged as one of the most important nosocomial pathogens, mainly because of its ability to colonize implanted biomaterials by forming a biofilm. Extensive studies are focused on the molecular mechanisms involved in biofilm formation. The LytSR two-component regulatory system regulates autolysis and biofilm formation in Staphylococcus aureus. However, the role of LytSR played in S. epidermidis remained unknown. Results In the present study, we demonstrated that lytSR knock-out in S. epidermidis did not alter susceptibility to Triton X-100 induced autolysis. Quantitative murein hydrolase assay indicated that disruption of lytSR in S. epidermidis resulted in decreased activities of extracellular murein hydrolases, although zymogram showed no apparent differences in murein hydrolase patterns between S. epidermidis strain 1457 and its lytSR mutant. Compared to the wild-type counterpart, 1457ΔlytSR produced slightly more biofilm, with significantly decreased dead cells inside. Microarray analysis showed that lytSR mutation affected the transcription of 164 genes (123 genes were upregulated and 41 genes were downregulated. Specifically, genes encoding proteins responsible for protein synthesis, energy metabolism were downregulated, while genes involved in amino acid and nucleotide biosynthesis, amino acid transporters were upregulated. Impaired ability to utilize pyruvate and reduced activity of arginine deiminase was observed in 1457ΔlytSR, which is consistent with the microarray data. Conclusions The preliminary results suggest that in S. epidermidis LytSR two-component system regulates extracellular murein hydrolase activity, bacterial cell death and pyruvate utilization. Based on the microarray data, it appears that lytSR inactivation induces a stringent response. In addition, LytSR may indirectly enhance biofilm formation by altering the metabolic status of the bacteria.

  16. ¹³C metabolic flux analysis identifies an unusual route for pyruvate dissimilation in mycobacteria which requires isocitrate lyase and carbon dioxide fixation.

    Directory of Open Access Journals (Sweden)

    Dany J V Beste

    2011-07-01

    Full Text Available Mycobacterium tuberculosis requires the enzyme isocitrate lyase (ICL for growth and virulence in vivo. The demonstration that M. tuberculosis also requires ICL for survival during nutrient starvation and has a role during steady state growth in a glycerol limited chemostat indicates a function for this enzyme which extends beyond fat metabolism. As isocitrate lyase is a potential drug target elucidating the role of this enzyme is of importance; however, the role of isocitrate lyase has never been investigated at the level of in vivo fluxes. Here we show that deletion of one of the two icl genes impairs the replication of Mycobacterium bovis BCG at slow growth rate in a carbon limited chemostat. In order to further understand the role of isocitrate lyase in the central metabolism of mycobacteria the effect of growth rate on the in vivo fluxes was studied for the first time using ¹³C-metabolic flux analysis (MFA. Tracer experiments were performed with steady state chemostat cultures of BCG or M. tuberculosis supplied with ¹³C labeled glycerol or sodium bicarbonate. Through measurements of the ¹³C isotopomer labeling patterns in protein-derived amino acids and enzymatic activity assays we have identified the activity of a novel pathway for pyruvate dissimilation. We named this the GAS pathway because it utilizes the Glyoxylate shunt and Anapleurotic reactions for oxidation of pyruvate, and Succinyl CoA synthetase for the generation of succinyl CoA combined with a very low flux through the succinate--oxaloacetate segment of the tricarboxylic acid cycle. We confirm that M. tuberculosis can fix carbon from CO₂ into biomass. As the human host is abundant in CO₂ this finding requires further investigation in vivo as CO₂ fixation may provide a point of vulnerability that could be targeted with novel drugs. This study also provides a platform for further studies into the metabolism of M. tuberculosis using ¹³C-MFA.

  17. Cloning and Characterization of a Pyruvate Carboxylase Gene from Penicillium rubens and Overexpression of the Genein the Yeast Yarrowia lipolytica for Enhanced Citric Acid Production.

    Science.gov (United States)

    Fu, Ge-Yi; Lu, Yi; Chi, Zhe; Liu, Guang-Lei; Zhao, Shou-Feng; Jiang, Hong; Chi, Zhen-Ming

    2016-02-01

    In this study, a pyruvate carboxylase gene (PYC1) from a marine fungus Penicillium rubens I607 was cloned and characterized. ORF of the gene (accession number: KM397349.1) had 3534 bp encoding 1177 amino acids with a molecular weight of 127.531 kDa and a PI of 6.20. The promoter of the gene was located at -1200 bp and contained a TATAA box, several CAAT boxes and a sequence 5'-SYGGRG-3'. The PYC1 deduced from the gene had no signal peptide, was a homotetramer (α4), and had the four functional domains. After expression of the PYC1 gene from the marine fungus in the marine-derived yeast Yarrowia lipolytica SWJ-1b, the transformant PR32 obtained had much higher specific pyruvate carboxylase activity (0.53 U/mg) than Y. lipolytica SWJ-1b (0.07 U/mg), and the PYC1 gene expression (133.8%) and citric acid production (70.2 g/l) by the transformant PR32 were also greatly enhanced compared to those (100 % and 27.3 g/l) by Y. lipolytica SWJ-1b. When glucose concentration in the medium was 60.0 g/l, citric acid (CA) concentration formed by the transformant PR32 was 36.1 g/l, leading to conversion of 62.1% of glucose into CA. During a 10-l fed-batch fermentation, the final concentration of CA was 111.1 ± 1.3 g/l, the yield was 0.93 g/g, the productivity was 0.46 g/l/h, and only 1.72 g/l reducing sugar was left in the fermented medium within 240 h. HPLC analysis showed that most of the fermentation products were CA. However, minor malic acid and other unknown products also existed in the culture.

  18. Clenbuterol, a β2-adrenergic agonist, reciprocally alters PGC-1 alpha and RIP140 and reduces fatty acid and pyruvate oxidation in rat skeletal muscle.

    Science.gov (United States)

    Hoshino, Daisuke; Yoshida, Yuko; Holloway, Graham P; Lally, James; Hatta, Hideo; Bonen, Arend

    2012-02-01

    Clenbuterol, a β2-adrenergic agonist, reduces mitochondrial content and enzyme activities in skeletal muscle, but the mechanism involved has yet to be identified. We examined whether clenbuterol-induced changes in the muscles' metabolic profile and the intrinsic capacity of mitochondria to oxidize substrates are associated with reductions in the nuclear receptor coactivator PGC-1 alpha and/or an increase in the nuclear corepressor RIP140. In rats, clenbuterol was provided in the drinking water (30 mg/l). In 3 wk, this increased body (8%) and muscle weights (12-17%). In red (R) and white (W) muscles, clenbuterol induced reductions in mitochondrial content (citrate synthase: R, 27%; W, 52%; cytochrome-c oxidase: R, 24%; W, 34%), proteins involved in fatty acid transport (fatty acid translocase/CD36: R, 36%; W, 35%) and oxidation [β-hydroxyacyl CoA dehydrogenase (β-HAD): R, 33%; W, 62%], glucose transport (GLUT4: R, 8%; W, 13%), lactate transport monocarboxylate transporter (MCT1: R, 61%; W, 37%), and pyruvate oxidation (PDHE1α, R, 18%; W, 12%). Concurrently, only red muscle lactate dehydrogenase activity (25%) and MCT4 (31%) were increased. Palmitate oxidation was reduced in subsarcolemmal (SS) (R, 30%; W, 52%) and intermyofibrillar (IMF) mitochondria (R, 17%; W, 44%) along with reductions in β-HAD activity (SS: R, 17%; W, 51%; IMF: R, 20%; W, 57%). Pyruvate oxidation was only reduced in SS mitochondria (R, 20%; W, 28%), but this was not attributable solely to PDHE1α, which was reduced in both SS (R, 21%; W, 20%) and IMF mitochondria (R, 15%; W, 43%). These extensive metabolic changes induced by clenbuterol were associated with reductions in PGC-1α (R, 37%; W, 32%) and increases in RIP140 (R, 23%; W, 21%). This is the first evidence that clenbuterol appears to exert its metabolic effects via simultaneous and reciprocal changes in the nuclear receptor coactivator PGC-1α and the nuclear corepressor RIP140.

  19. 76 FR 68101 - Safety Zone; Art Gallery Party St. Pete 2011 Fireworks Display, Tampa Bay, St. Petersburg, FL

    Science.gov (United States)

    2011-11-03

    ... [Docket No. USCG-2011-0774] RIN 1625-AA00 Safety Zone; Art Gallery Party St. Pete 2011 Fireworks Display... St. Petersburg, Florida during the Art Gallery Party St. Pete 2011 Fireworks Display on Friday... November 11, 2011, Creative Pyrotechnics is sponsoring the Art Gallery Party St. Pete 2011 Fireworks...

  20. 78 FR 16780 - Special Local Regulation; 2013 International Rolex Regatta; St. Thomas Harbor; St. Thomas, U.S...

    Science.gov (United States)

    2013-03-19

    ... 1625-AA08 Special Local Regulation; 2013 International Rolex Regatta; St. Thomas Harbor; St. Thomas, U... is establishing special local regulations on the waters of St. Thomas Harbor in St. Thomas, U. S.... Thomas Yacht Club is sponsoring the 2013 Rolex Regatta, a series of sail boat races. The races will be...

  1. The Role of the st313-td Gene in Virulence of Salmonella Typhimurium ST313

    DEFF Research Database (Denmark)

    Herrero-Fresno, Ana; Wallrodt, Inke; Leekitcharoenphon, Pimlapas

    2014-01-01

    Multidrug-resistant Salmonella enterica serovar Typhimurium ST313 has emerged in sub-Saharan Africa causing severe infections in humans. Therefore, it has been speculated that this specific sequence type, ST313, carries factors associated with increased pathogenicity. We assessed the role...

  2. St. Thomas and St. John, U.S. Virgin Islands Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1/3 arc-second St. Thomas and St. John, U.S. Virgin Islands Coastal Digital Elevation Model will be used to support NOAA's tsunami forecast system and for...

  3. The marine Algal Vegetation of St. Martin, St. Eustatius and Saba (Netherlands Antilles)

    NARCIS (Netherlands)

    Vroman, M.

    1968-01-01

    Along the coast of St. Martin, St. Eustatius and Saba the rocks above sea-level often show a number of differently coloured zones. This is clearly visible when the coast over a larger distance is formed by one type of rock, as for instance on Saba. In many places a light-coloured belt is seen above

  4. ST depression in lead aVL differentiates inferior ST-elevation myocardial infarction from pericarditis.

    Science.gov (United States)

    Bischof, Johanna E; Worrall, Christine; Thompson, Peter; Marti, David; Smith, Stephen W

    2016-02-01

    ST-segment elevation (STE) due to inferior STE myocardial infarction (STEMI) may be misdiagnosed as pericarditis. Conversely, this less life-threatening etiology of ST elevation may be confused for inferior STEMI. We sought to determine if the presence of any ST-segment depression in lead aVL would differentiate inferior STEMI from pericarditis. Retrospective study of 3 populations. Cohort 1 included patients coded as inferior STEMI, cohort 2 included patients with a discharge diagnosis of pericarditis who presented with chest pain and at least 0.5 mm of ST elevation in at least 1 inferior lead. We analyzed the presenting electrocardiogram in both populations, with careful assessment of leads II, III, aVF, and aVL. In addition, we retrospectively studied a third cohort of patients with subtle inferior STEMI (pericarditis group, all 49 had some inferior STE but none had any ST-segment depression in lead aVL (specificity, 100%; confidence interval, 91%-100%). In the third cohort, there were 272 inferior MIs with coronary occlusion, of which 54 were "subtle." Of these, 49 had some ST depression in lead aVL. When there is inferior ST-segment elevation, the presence of any ST depression in lead aVL is highly sensitive for coronary occlusion in inferior myocardial infarction and very specific for differentiating inferior myocardial infarction from pericarditis. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Three members of Medicago truncatula ST family are ubiquitous during development and modulated by nutritional status (MtST1) and dehydration (MtST2 and MtST3).

    Science.gov (United States)

    Albornos, Lucía; Martín, Ignacio; Labrador, Emilia; Dopico, Berta

    2017-07-10

    ShooT specific/Specific Tissue (ST) belong to a protein family of unknown function characterized by the DUF2775 domain and produced in specific taxonomic plant families, mainly Fabaceae and Asteraceae, with the Medicago truncatula ST family being the largest. The putative roles proposed for this family are cell elongation, biotic interactions, abiotic stress and N reserve. The aim of this work was to go deeper into the role of three M. truncatula ST proteins, namely ST1, ST2 and ST3. Our starting hypothesis was that each member of the family could perform a specific role, and hence, each ST gene would be subjected to a different type of regulation. The search for cis-acting regulatory elements (CREs) in silico in pST1, pST2 and pST3 promoters showed prevalence of tissue/organ specific motifs, especially root- and seed-specific ones. Light, hormone, biotic and abiotic related motifs were also present. None of these pSTs showed the same combination of CREs, or presented the same activity pattern. In general, pST activity was associated with the vascular cylinder, mainly in roots. Promoter activation was highly specific and dissimilar during reproductive development. The ST1, ST2 and ST3 transcripts accumulated in most of the organs and developmental stages analysed - decreasing with age - and expression was higher in the roots than in the aerial parts and more abundant in light-grown plants. The effect of the different treatments on transcript accumulation indicated that ST1 behaved differently from ST2 and ST3, mainly in response to several hormones and dehydration treatments (NaCl or mannitol), upon which ST1 transcript levels decreased and ST2 and ST3 levels increased. Finally, the ST1 protein was located in the cell wall whereas ST2 and ST3 were present both in the cytoplasm and in the cell wall. The ST proteins studied are ubiquitous proteins that could perform distinct/complementary roles in plant biology as they are encoded by differentially regulated genes

  6. VaST: A variability search toolkit

    Science.gov (United States)

    Sokolovsky, K. V.; Lebedev, A. A.

    2018-01-01

    Variability Search Toolkit (VaST) is a software package designed to find variable objects in a series of sky images. It can be run from a script or interactively using its graphical interface. VaST relies on source list matching as opposed to image subtraction. SExtractor is used to generate source lists and perform aperture or PSF-fitting photometry (with PSFEx). Variability indices that characterize scatter and smoothness of a lightcurve are computed for all objects. Candidate variables are identified as objects having high variability index values compared to other objects of similar brightness. The two distinguishing features of VaST are its ability to perform accurate aperture photometry of images obtained with non-linear detectors and handle complex image distortions. The software has been successfully applied to images obtained with telescopes ranging from 0.08 to 2.5 m in diameter equipped with a variety of detectors including CCD, CMOS, MIC and photographic plates. About 1800 variable stars have been discovered with VaST. It is used as a transient detection engine in the New Milky Way (NMW) nova patrol. The code is written in C and can be easily compiled on the majority of UNIX-like systems. VaST is free software available at http://scan.sai.msu.ru/vast/.

  7. Draft Genome Sequences of Staphylococcus aureus AMRF1 (ST22) and AMRF2 (ST672), Ocular Methicillin-Resistant Isolates

    KAUST Repository

    Velusamy, Nithya

    2014-03-20

    Sequence type 22 (ST22) and ST672 are the two major emerging clones of community-acquired methicillin-resistant Staphylococcus aureus in India. ST672 strains were found to cause severe ocular infections. We report the draft genome sequences of two emerging strains of methicillin-resistant S. aureus, AMRF1 (ST22) and AMRF2 (ST672), isolated from patients with ocular infections.

  8. Selective Reproduction in the 21st Century

    DEFF Research Database (Denmark)

    In the 21st century, human reproduction increasingly involves decisions about which gametes to fertilize, which embryos to implant, or which fetuses to abort. The term ‘selective reproduction’ refers to these increasingly widespread efforts to bring specific kinds of children into being. To this ......In the 21st century, human reproduction increasingly involves decisions about which gametes to fertilize, which embryos to implant, or which fetuses to abort. The term ‘selective reproduction’ refers to these increasingly widespread efforts to bring specific kinds of children into being...... detection of fetal anomalies during prenatal screening and testing programs, the development of preimplantation genetic diagnosis techniques as well as the screening of potential gamete donors by egg agencies and sperm banks. Selective Reproduction in the 21st Century provides unique ethnographic insights...

  9. Analyse of Maintenance Cost in ST

    CERN Document Server

    Jenssen, B W

    2001-01-01

    An analyse has been carried out in ST concerning the total costs for the division. Even though the target was the maintenance costs in ST, the global budget over has been analysed. This has been done since there is close relation between investments & consolidation and the required level for maintenance. The purpose of the analyse was to focus on maintenance cost in ST as a ratio of total maintenance costs over the replacement value of the equipment, and to make some comparisons with other industries and laboratories. Families of equipment have been defined and their corresponding ratios calculated. This first approach gives us some "quantitative" measurements. This analyse should be combined with performance indicators (more "qualitative" measurements) that are telling us how well we are performing. This will help us in defending our budget, make better priorities, and we will satisfy the requirements from our external auditors.

  10. Materials for the 21st century

    CERN Document Server

    Segal, David

    2017-01-01

    The book is a general text that shows how materials can contribute to solving problems facing nations in the 21st century. It is illustrated with diverse applications and highlights the potential of existing materials for everyday life, healthcare and the economies of nations. There are 13 chapters and a glossary of 500 materials with their descriptions, historical development, their use or potential use and a range of references. Specific areas include synthetic polymers (e.g. nylon), natural polymers (e.g. proteins, cellulose) and the role of materials in the development of digital computers and in healthcare. Solid-state lighting, energy supplies in the 21st century, disruptive technologies and intellectual property, in particular patents, are discussed. The book concludes by asking how the 21st century will be characterised. Will it be the Silicon Age, Genomic Age or New Polymer Age, as examples?

  11. Detection of methicillin-resistant Staphylococcus pseudintermedius ST169 and novel ST354 SCCmec II-III isolates related to the worldwide ST71 clone.

    Science.gov (United States)

    Ishihara, K; Koizumi, A; Saito, M; Muramatsu, Y; Tamura, Y

    2016-01-01

    The recent appearance of methicillin-resistant Staphylococcus pseudintermedius (MRSP) is a concern for both veterinary and human healthcare. MRSP clonal lineages with sequence type (ST) 71-spa t02-staphylococcal cassette chromosome mec (SCCmec) II-III and ST68-spa t06-SCCmec V have spread throughout Europe and North America, respectively. The current study compared the molecular characteristics of 43 MRSP isolates from dogs in Japan with those of MRSP from previous reports using multilocus sequence typing based on seven housekeeping genes, SCCmec typing, and detection of antimicrobial resistance genes. Three related clonal lineages, ST71, ST169, and the newly registered ST354, were observed in SCCmec II-III isolates from Japan, despite MRSP SCCmec II-III isolates being thought to belong to a single clonal lineage. The majority of SCCmec II-III isolates belonging to ST169 (9/11) and ST354 (3/3), but not ST71 (0/11), harboured tetM. Four STs were observed for the SCCmec V isolates; however, neither ST68 nor related STs were found in the Japanese MRSP isolates. In conclusion, MRSP SCCmec II-III isolates from Japan belonged to ST71 and related STs (ST169 and ST354). A variety of MRSP SCCmec V clones, including some novel clones, were identified.

  12. The 21st Century as Whose Century?

    Directory of Open Access Journals (Sweden)

    David Scott

    2015-08-01

    Full Text Available Macro-analysis and East-West encounter are shown through consideration of objective yet subjective constructed concepts for the international system and international economy in the 21st century. Three paradigms are considered, namely the 21st century as the ‘Pacific Century’, as ‘China’s Century’ and as the ‘Asian Century’. Overlaps are shown between these three paradigms, as also developments in time, and gradually shift in geographical location. The ‘Pacific Century’, and its associated Rimspeak, was the paradigm emerging in the late 1970s, knitting together America’s West Coast and the Japanese economy. By the late 1980s this was already shifting to talk of the 21st century likely to be an ‘Asian Century’ model, mark-1, based on the Pacific Asia dynamism shown by the ‘Asian Tigers’ and Japan. However, the Asian financial crash of 1997-8, and the economic downturn in Japan, meant that such an ‘Asian Century’ seemed premature as the 21st century arrived. Instead, it was China’s economic growth that seemed most evident, and with it the concept of the 21st century as ‘China’s Century’. However, in turn that has already been modified during the first decade of the century by India’s arrival as a rapidly growing economy. Consequently the 21st century as ‘China’s Century’ and as ‘India’s Century’ has been combined into talk of an ‘Asian Century’, mark-2.

  13. Omsorg/støtte i ungdomsskolen

    OpenAIRE

    Vasseng, Eli Dahl

    2012-01-01

    Master's thesis in Special education Denne studien handler om forholdet mellom lærer-elev og ser på hvordan ungdomsskoleelever beskriver omsorgsfulle/støttende lærere og den betydning det har for motivasjon i skolearbeid og læringsmiljø. Jeg har tatt utgangspunkt i ungdomsskoleelevenes forståelse av fenomenet omsorg/støtte og brukt en fenomenologisk tilnærming med intervju som metode. Seks elever fra ungdomstrinnet ble intervjuet og jeg har brukt en intervjuguide som er bygget på det teore...

  14. 51st North American Chemical Residue Workshop.

    Science.gov (United States)

    Yang, Paul; Martos, Perry; Barrett, Brad

    2015-06-03

    Manuscripts collected in this 51st North American Chemical Residue Workshop (NACRW) Symposium issue of the Journal of Agricultural and Food Chemistry (JAFC) were originally presented at the 51st NACRW meeting. The 2014 NACRW JAFC symposium collects 14 publications representing the broad range of topics in chemical analyses presented at the 2014 meeting. These include the analysis of chemical residues and contaminants in food, environment, feed, botanical, and bee samples as well as the application of quality control/quality assurance protocols in routine and method development.

  15. Statistics in the 21st century

    CERN Document Server

    Wells, Martin T; Wells, Martin T

    2001-01-01

    Exactly what is the state of the art in statistics as we move forward into the 21st century? What promises, what trends does its future hold? Through the reflections of 70 of the world's leading statistical methodologists, researchers, theorists, and practitioners, Statistics in the 21st Century answers those questions. Originally published in the Journal of the American Statistical Association, this collection of vignettes examines our statistical past, comments on our present, and speculates on our future. Although the coverage is broad and the topics diverse, it reveals the essential intell

  16. Kirjallisuuskatsaus tiimityöstä

    OpenAIRE

    Uimi, Jutta

    2012-01-01

    Laurea-ammattikorkeakoulu Tiivistelmä Laurea Lohja Hoitotyön koulutusohjelma Uimi Jutta Kirjallisuuskatsaus tiimityöstä Vuosi 2012 Sivumäärä 43 Tämän opinnäytetyön tavoitteena oli kuvata kirjallisuuskatsauksen muodossa, miten tiimityö määritellään terveydenhuollon organisaatiossa ja tiimityön käytettävyyttä sekä millaisissa yhteyksissä tiimityötä käytetään. Tarkoituksena oli tuottaa tutkittua tietoa tiimityöstä Helsingin ja Uudenmaan sairaanhoitopiiriin (HUS) kuulu...

  17. Verdens største blomsterudstilling

    DEFF Research Database (Denmark)

    Larsen, Bjarne

    2011-01-01

    Verdens største blomsterudstilling fi nder sted i udkanten af London hvert år i juli måned. Det er parken omkring det tidligere kongepalads Hampton Court palace, der danner de fantastiske omgivelser for det enorme blomster- og haveshow......Verdens største blomsterudstilling fi nder sted i udkanten af London hvert år i juli måned. Det er parken omkring det tidligere kongepalads Hampton Court palace, der danner de fantastiske omgivelser for det enorme blomster- og haveshow...

  18. Nursing theory: the 21st century.

    Science.gov (United States)

    Randell, B P

    1992-01-01

    On September 21, 1990, at the University of California, Los Angeles, Neuropsychiatric Institute and Hospital, six nurse theorists participated in a panel discussion on theory development for the 21st century. The theorists included Dorothy Johnson, Betty Neuman, Dorothea E. Orem, Rosemarie Rizzo Parse, Martha E. Rogers and Callista Roy. The panel provided the participants the opportunity to speculate on the course for future development of nursing knowledge. Three questions were posed to the panel relating to the development of their models, the direction nursing theory will take in the 21st century, and current research emerging from the extant theories. The panel also addressed questions from the audience.

  19. Mystic of St. Seraphim of Sarov and St. Francis of Assisi

    Directory of Open Access Journals (Sweden)

    Mirosław Białous

    2015-11-01

    Full Text Available This paper presents figures of St. Seraphim and St. Francis, comparing their mystic. Both saints are regarded as typical representatives of his age and his milieu: St. Seraphim – of the Eastern Orthodox Christian mystic, St. Francis – of the Christian West, the Roman Catholic mysticism. Similar was their life of poverty, similar the joy of life and the attitude towards nature, similar the ecclesial and sacramental dimension of their spirituality. But there were differences. St. Francis’ mystic is more associated with the sphere of emotional and material world, with the earthly reality. And St. Seraphim is a faithful follower of the monastic tradition of Mount Sinai, of Athos and of the other representatives of hesychasm who remaining in the earthly body experienced the spiritual liberation. These differences are visible, if we compare the experience of Christ by Seraphim on Great Thursday and the vision of St Francis on the mountain of Alvernia.

  20. REFORMED THEOLOGY FOR THE 21ST CENTURY ...

    African Journals Online (AJOL)

    pressed in these volumes warrant a thorough and detailed study. It is not feasible to give a summary of the .... resemble the faces of consecutive generations in a family photo album: They do not look alike … They do not .... as directive the presentation of the providence of God in the Heidelberg. Catechism, even for the 21st ...